Quality control Quality control

Quality control

Although the general principles of quality control for many years remain the same, now instead of the term "control" is often used the concept of "security".
In dictionaries the term "provide» (to assure) compared to "guarantee", whereas "control» (to control) is to control, regulate within certain authority. In this regard, the term "support" is more appropriate because management within the data authority often does not guarantee good results (which is worth bearing in mind the quality control managers).
In recent years, as well as for many years before that, we had to go to large and small businesses around the world. Approaches to comply with the quality they are significantly different - in some places almost no control at all, and other enterprises are laboratories performing multiple tests, but these tests often have no relation to the quality of the product.
Sometimes, employees of enterprises slightly familiar with the scientific principles and technology of production, with a minimal representation of such fundamental properties as relative humidity, water activity, cooling, and the solubility value of pH.
In large factories, control and regulation facilities are built into production lines, which allows for continuous technological monitoring. Signals of deviation from the specified characteristics of the final product are received in the early technological stages, where the correction of certain parameters is automatically performed. An example is the continuous production of fondant, in which minor changes in the moisture content can lead to appreciable deviations in the texture of the final product. Temperature sensors at the stage of syrup boiling convey information that allows adjusting the syrup consumption and vapor pressure.
Much more attention is being paid to microbiological parameters, since there were cases of food poisoning due to salmonella, E. coli (Escherichia coli) and other pathogens.
Significant changes have occurred in the package. If many before packaging constituted simply overlapping paper wrappers nowadays most confectionery, including chocolate, producing a sealable protective packaging. Such packaging material (film or laminate) is characterized by impermeability to water vapor and gases and protects the products from the most insects.
Quality Control Principles
Many books on quality control issues abound in mathematical formulas, and we owe much to mathematicians and statisticians, giving the manufacturer's recommendations for acceptance or culling of raw materials and finished products, but the quality control is not limited to statistical methods. To give the right advice, statisticians need factual information (usually a large amount), but often the knowledge of the technology would greatly reduce the need for mathematical data processing.
In the pastry industry in the past 60-70 years, there has been a shift from handicraft (manual) production to mass production with a high degree of automation and a relatively small number of operators who do not need extensive knowledge of confectionery. The product is developed by technologists, and engineers create equipment for stable release in accordance with the standard (technical conditions) determined by technologists and the marketing service. The quality and production process in accordance with the standard are then determined by the combination of precise raw material control and equipment control at all stages of the process, as well as statistical methods for checking the quality of the finished product. The latter include mass control, organoleptic analysis and packaging quality control.
Who determines the quality standard?
When developing a new product or changing existing technology, the quality standard is established by the head of the marketing and sales department (commercial service). This standard should, of course, be as high as possible while maintaining a reasonable price for the product in accordance with the requirements of the market for which it is oriented. There are many cases where the standard was too high quality of the product at a price that is acceptable only for a very small number of consumers. In the confectionery industry, the concept of quality includes packaging. At one end of the scale there are carefully designed exquisite boxes for assorted sets, and on the other - simple wraps of chocolate-glazed bars that simply inform the buyer about the contents and provide some protection for the product.
In accordance with modern concepts of quality standards should be set at a fairly early stage of product development, and include the type of packaging. The acquisition of highly mechanized equipment for the mass production of confectionery bars may require a very large capital expenditures in connection with what is necessary to determine exactly what should be the production line (including quality standards) before ordering it, as changes at a later stage can be very expensive.
Who controls the quality?
Responsibility for production in accordance with the quality standard lies entirely with the production units where engineers and technologists are currently working. It is completely wrong to consider that the quality department is responsible for the quality control department (or OTK). With this approach, the production staff begins to take care only of the quantity, not quality, and the units engaged in quality control are forced to reject unsuitable products at the output of the production line, which is very wasteful. The real task of the quality control department is timely provision of information on the observed deviations from the quality standard.
How to be organized quality control?
As a control, there are three areas: control of raw materials, strictly control the production process and control of the finished product.
The primary responsibility of quality control departments - authorizing the use of raw materials for the production and control of the finished product. This requires contact with the production staff, and to achieve the most effective results requires a certain tact and "diplomatic" efforts. Check - it's not just quality control, it means the reception of raw materials or finished product culling. Value culling is that based on it can be given advice on how to prevent further occurrence of marriage.
Testing of the finished product should also include a survey of stocks in warehouses and stores. Many companies include within the scope of responsibilities of the quality control department to study the claims and check retail outlets.
Acceptance or culling of raw materials is usually the responsibility of the laboratory staff included, as a rule, in the quality control department. Chemical analysis is important to determine whether the type of raw material specifications agreed upon, but is important and visual inspection of the parties as a whole. If such a check very quickly becomes a damaged bags or boxes, the need to define batch numbers the manufacturer and thus greatly reduce the amount of required sampling.
Testing is usually combined with sampling, and it allows the employee, whose duties include sampling, perform a visual inspection of raw materials in open bags or boxes. It is possible to make a fairly complete picture of deviations as a raw material, its purity or contamination.
Sampling - the most important part of the control of raw materials, and properly taken sample or trial, are not typical for the party, endanger correct subsequent analysis in general, and may even cause damage to the large volume of product. Employee performing sampling, must be reliable, and follow the instructions.
Statisticians can recommend the best method of sampling from the party on the basis of purely mathematical models, but the technologist or analyst usually have the advantage that they know the product, its origin, and exposure to changes in the impact of these changes on the final product. This knowledge usually can significantly reduce the number of samples to be taken and analyzes conducted.
Presented below feed control procedures based on common sense and has been used successfully with a very small number of errors. The need for on the basis of sampling and testing of purely statistical approach is very rare.
Type of raw materials
Some raw materials are almost pure substances. Sugar, for example, more than 99,9% is a pure chemical substance (sucrose), and if the source of raw materials and a manufacturer known, does not make sense to carry out its detailed analysis. Usually it is sufficient to perform inspection of the external party (assuming the sugar is delivered in bags) for local damage or contamination and to check the color of manufactured syrup single representative sample.
To a similar category are glucose syrup (molasses), starch and fats. Glucose can be of varying degrees of saccharification, fats can have different melting points, and starch can be used for casting mass or as an ingredient in the formulation. In such cases, for the description of the product, all packages, boxes or bags should be appropriately marked (the bulk supply issues will be discussed below). A visual inspection of the entire batch and a limited analysis of a representative number of samples are performed (for example, determination of the melting point of fat). Essential oils, other aromatic substances, spices, cocoa beans, nuts, dried fruits, egg whites and other similar materials require a different approach. Essential oils can be a problem if their origin is not entirely clear. In this case, it is necessary to take more samples and perform some measurements (for example, the specific gravity, the direction of rotation of the plane of polarization of light and the refractive index) to determine the aroma. It is very important to determine the purity, since raw materials contaminated with metals (in particular, lead and copper) are often found. Spices along with aroma testing need microbiological control and checking for the presence of foreign impurities. Cocoa beans require a "slice test" to ensure that they are properly fermented. Nuts and dried fruits require careful testing for taste / smell, for foreign matter and for moisture content.
From the foregoing, it is clear, as a check should be carried out, and where necessary, can be used more detailed checks. For more information, see. Other sections of the book devoted to certain types of raw materials, as well as numerous for the tehnohimkontrolya management.
Knowledge of supplier of raw materials used by them production and quality control methods greatly affects how much detail should be carried out on the input control of the confectionery industry.
Manufacturers of most types of raw materials (especially ingredients that are supplied in large quantities) have improved and mechanized their production methods in the same way as they did in the confectionery industry. Quality control was also improved. It is desirable that the head of the chemical laboratory and the head of the procurement department, in a detailed discussion with the supplier, agree on the required characteristics of the raw materials, the type of packaging, the marking of batches and the shelf life. Laboratory staff performing quality control of raw materials should familiarize themselves with the control methods used in the supplier's laboratory.
This greatly simplifies the task of raw materials and consumer control reduces to a minimum. In many cases, the supplier of each party presents a certificate of analysis (in the case of bulk delivery of its presence is a prerequisite).
When working with a new supplier or a new ingredient in the procedure described above is only possible to establish good relations of the supplier and the consumer.
Acceptance of raw materials and its preparation for use in the manufacture of
Sugar, glucose syrup, mixed syrups and fats are supplied to large enterprises in the automotive and rail tank cars. Similar methods are used for the transportation of liquid chocolate, coatings, cocoa butter and milk products when they are between enterprises of one firm or if the factory specializing in the production of chocolate for enrobing, delivers it to another company which does not have the appropriate equipment.
The tank usually comes in from 10 to 20 t, and when it arrives at the factory, the contents of the tank are pumped into storage tanks (which may contain several hundred tons of product). If from the tank the contaminated contents or other substance enter the storage tank, this will have catastrophic consequences, and therefore it is necessary to carry out an operative control of the sample from the tank. Usually, it is not possible to detain the tank for the time of the chemical analysis, however, using electronic methods, it is possible to measure the specific gravity or moisture content. The sample should always be checked organoleptically for the presence of foreign inclusions.
Above we noted that most of the suppliers of raw materials to each batch of bulk cargo provide a "certificate of conformity", and in this case, prior to discharge into the store enough to perform organoleptic sample analysis. It is very likely that the enterprise vendor during the production were carried out chemical analysis and other quality assessment, and they are shipped only tested party, which authorized the shipment accordingly.
Many kinds of food raw materials are still delivered in paper or cloth bags, in wooden or cardboard boxes or barrels. In recent years found wide application thick polyethylene bags or less thick polyethylene liners of paper or cloth bags.
First, an external inspection of the arriving party is carried out and a representative sample for analysis is taken. If there is no preliminary information on the consignment (batch number, vendor data on the physico-chemical analysis performed), the sample should be taken by a method known as random selection. This method consists in numbering each package or group of packages and then referring to the tables of random numbers found in many works on statistics. Then, having selected a sample or samples, it is necessary to decide whether to return or accept the cargo. As if the supplier did not seek to improve the quality control system for the production of its product, it has to put up with some degree of variation in its quality. Similarly, a consumer must be brought in, who must be prepared for the presence of permissible deviations from the quality standards.
Whenever possible, if the ranges of variations are known, we can calculate the required number of samples can be confident that the risk to accept or reject the goods defective good, very small.
To perform the analysis of the delivered parts in individual containers in laboratory workers is usually longer. Such analyzes are necessary to test raw materials, in doubt by visual inspection of the cargo.
After receiving the incoming party, it must be sent to the production, which means opening the packaging and dispensing. It is very desirable to work with containers at production sites (except, perhaps, drums), as the product can get foreign objects - nails, splinters, staples, wire, pieces of paper or polyethylene. Emptying bags can also result in the ingress of dirt or fiber raw material on the outside of the bag, and therefore prior to emptying the bag must always be cleaned.
Tara should be opened in a special room for the preparation of a production batch of raw materials or in the warehouse, where special measures to combat pollution can be taken. In many cases, it is desirable to apply the contents of the package in metal tanks, which are installed in manufacturing plants (the raw material of the packages can be unloaded in dosing or automatic weighing equipment mechanically).
With the opening of the container should be used to detect any possibility of raw material defects. This staff must immediately report all unusual. The same applies to personnel working on the premises for the preparation of raw materials and production halls, which once again underlines the fact that responsible for quality control and production staff.
Another point that regulates quality is the choice of an alternative supplier of raw materials. The laboratory worker, engaged in quality control, after a chemical analysis and the release of several pilot batches at the enterprise, may recommend changing the source of raw material supply. Sometimes you can choose a cheaper supplier, even if some raw material quality indicators are below the standard. Sometimes the application of a minimum special treatment can improve the quality of raw materials and make it quite suitable for the release of a finished product of high quality. In such cases, the cost of additional processing should be commensurate with the lower price of the material. Often the use of additional processing is quite a lucrative business.
More difficult is the decision to use a substitute raw material - for example, replacing the egg white with another foaming agent. Such a decision is beyond the competence of the laboratory supervisor of quality (in the scope of his duties only control is included), and is carried out by a group of product developers who conduct laboratory experiments and, if these experiments prove promising, they make prototype batches, and the finished product is presented to members of the tasting commission . If the samples obtained are acceptable, they are tested for shelf life.
process control
In recent years, the methods of production in the confectionery industry have changed significantly, in particular, more continuous processes have been used instead of periodic ones. In a batch process, control is mainly carried out by two people - one who weighs the ingredients in accordance with a given recipe, and one who releases a batch of the product. The first uses scales and dimensional containers, and the second uses a thermometer or, if it tends to keep pace with the times, also a refractometer. Sometimes both of these functions are performed by one person, and it is clear that the quality is highly dependent on the conscientiousness and knowledge of the staff. The more the output, the greater the number of parties and the more likely the risk of quality deviations from different parties. The same goes for the staff.
Quality control of a large number of small parties - a serious problem in itself, but a statistical approach requires a large number of test samples.
It is necessary to check the taste, aroma characteristics of each sample, and many samples can be carried out at least one analysis (usually for moisture analysis). In practice, for the production of this kind of necessary quality checks are carried out, and the resulting properties of the product may vary significantly.
An alternative to a large number of small batches and, accordingly, a large amount of control is the increase in the size of batches or the continuous release of the product. Unfortunately, in the confectionery industry, before the introduction of new technologies and equipment, they often do not sufficiently study their influence on the quality of products, especially taste and aromatic properties. As a result, for a long time the technological processes were treated with distrust as if they did not provide the required quality of products. In many enterprises, if you need to increase the output of products instead of using a continuous production cycle, an automatic batch system is installed in which, for example, the lines of steam boilers (of the same type used for the production of batches by hand) are automatically filled with ingredients, boiled for exactly the specified period Time, and then automatically unloaded. Although this system can be very complex and witty, its application is not scientifically justified - it is more reasonable and fruitful to first study the actual periodic process. In the process of such a study, the cooking time, the time of finding the product in the boilers under the desired temperature conditions, the effect of the addition sequence of the ingredients, the determination of the time and reactions occurring at the final stage are recorded. As a result, data are obtained for the development of a continuous process.
In batch processes, cooking and cooling time is usually longer than continuous processes. The impact of such differences is illustrated by the following examples.
Milk candy, fudge. Taste, flavor, and color caused by the Maillard reaction between milk proteins and sugar. The longer the cooking time, the stronger developing flavor, aroma and color. When short-term continuous processes for the formation of flavor and aroma, additional chamber ramelizatory (see. 19 chapter).
Pectin jelly. To pour the jelly pectin requires a certain acidity. boiling mass causes a significant inversion of sugar (at short-term continuous process of inversion is much less).
Microbiological properties. Raw materials (cocoa powder, nuts, canned fruits, some dairy products and egg protein) contains enzymes and mold. In a continuous process, they are not always deleted (especially if the components are added near the end of the process).
Sometimes problems can arise due to the nature of the continuous process. A typical example is the production of creamy fudge. When the creamy fudge mass (fudge) is released by the periodic technology, the burnt sugar is heated to about 118-121 ° C and cooled on a baking sheet to about 82 ° C, after which the lipstick is quickly mixed on it. Then the mixture is poured onto a table where it cools down in a stationary state and a characteristic crystalline structure is formed. Such creamy fudge has a certain strength and can be rolled, cut and glazed without signs of destruction. If the cream lipstick is made and cooled on a baking sheet with continuous stirring, the crystal structure is destroyed, and the creamy fudge turns into a soft paste, which is difficult to work with. With continuous technologies, excessive mixing often occurs, and if a continuous frying machine is used for making creamy fudge, and then a continuous chiller (the product is mixed there and there), it is necessary to add components near the point of exit of the product from Cooling tunnel, but providing enough time for the distribution of lipstick components in the burnt sugar. The final cooling of the mixture is best carried out on the belt of the conveyor, where the growth of the crystals provides a more stable mass, which can then be shaped (rolled, cut or extruded, as with batch technology) and stored.
Integrated Process Control System
In the confectionery industry, much attention is paid to such systems. They were developed in the chemical and petroleum industries on the basis of certain physical or chemical characteristics - boiling point, density, viscosity, refractive index, pH, color, etc. In the case of batch processes, these parameters are measured manually (usually only for parts of batches) Laboratory instruments or their stationary modifications intended for use in production. For on-line monitoring, continuous recording devices are used that provide signals to controllers that control valves that control vapor pressure, the flow of liquids or solids, which allows you to quickly correct the defects found in the final product.
When developing the control system for the technological line, it is first necessary to determine the critical points and to determine the control methods for all points. The main principle of this is best explained on the example of the development of a continuous technology for manufacturing a bar of foamed sugar solution, manufactured for many years by periodic technology. The process is simple - in the boiling syrup, bicarbonate soda (sodium bicarbonate) is added, mixed well and the mass is poured onto the tables for cooling and maturing. Then the mass is cut into bars. In periodic technology, the process is broken down into small batches - it is necessary to cut the seams, and too thin strata to be sent to the marriage, then to process it using an expensive process of discoloration and filtration.
Continuous technology was developed after a large number of experiments. Installation diagram indicating the critical control points is shown in Fig. 23.1. Two of the most important point in the system - it is a point in I 1 where recorded syrup boiling point which determines the final texture of the product and influences the form and density of the porous structure and K in 2 point where controlled
23.1 Fig. 23.1. The technological scheme of installation with built-in automated system
Feed ingredients, the quality of which is closely monitored. flow control and quality of sodium bicarbonate and a suspension.
Automatic dosing, volume or weight (a critical point 1).
An apparatus for continuous dissolution filing syrup constant composition O. Storage Tank syrup
E. Adjustable pump feeding the syrup to the heat exchanger (the critical point 2)
R. Plate heat exchanger, through which the control valve in the steam is high (critical point 3) who pressure.
N. Thermometer, working on the principle of measuring the electrical resistance (a critical point 4). a flow sensor in the syrup at the outlet of the heat exchanger This syrup is fed into a continuous mixer, into which the slurry is fed from a small reservoir foaming E.
K. Peristaltic pump adjustable performance (critical point 5).
The hot mass is discharged from the /. M on the conveyor, where the reaction proceeds in the product and, ultimately, a uniform thickness is achieved.
N. The recording control device thickness.
sodium bicarbonate entering the mixer, which affects the thickness of the layer on the tape, the degree of aeration, taste, smell and color of the final product.
Pump supplying the slurry with sodium bicarbonate, it should be very accurately adjusted, since it ra.skhod very small compared with the flow rate of the syrup, and a small error in the amount of syrup delivered immediately affects the thickness and weight of the color on the tape. This effect is so significant that the correction is easy to perform manually on the testimony of the device, which measures the thickness. A more reliable method - automatic pump of sodium bicarbonate using a thickness gauge.
In addition to the main points of control, shown in the figure, there are mechanical devices that control the temperature, the width and the uniformity of the mass on the tape. The cooled product is fed to the cutting machines, therefore characterized by a constant quality, and checks are rarely required. In general, they are reduced to the determination of sugars in the starting syrup ratio, the measurement of moisture and density.
For the latest developments in this area relates to the control of a computer, allowing the monitor to instantly reflect the conditions existing at the critical points.
Control of finished product
If properly conducted quality control of raw materials and production technology, testing of the finished product are not necessary, but such a state of affairs at the company - it is a utopia. However, the embedded control system can reduce the volume of the finished product inspection and the number of cases it may reject achieve very low levels.
Even in the advanced enterprises with conscientious workers sometimes things do not go wrong, and to check the correctness of the previous process steps necessary to control the finished product. The problem is to determine the minimum amount of control that does not come cheap. It is unreasonable to first reduce the cost of production workers and then hire a staff of inspectors. It is not only relatively expensive in financial terms, but also bad for the ratio of workers to the case.
At the end of the confectionery production line hundreds of packaged products come at any moment, and you need to decide what kind of control should be carried out. The most important control
  • appearance of the product (as a product, and packaging);
  • taste;
  • product weight.
Controllers in the enterprise have a "control sample" - the packaging of products. The contents of the package and the wrapper without presented in trays. The control sample must be approved by marketing and quality control of the service department.
Probootbor and wine tasting
Samples taken for weight control (see. Below) are evaluated in appearance and postponed for later tasting carried out by the methods described in Chapter 18.
Often tastings are carried out on a sample taken from the original nerasfasovan- tion party. The chocolate storage tank, for example, may be 5 t, from which the 90 thousand. Bars weighing approximately 60 In this case, the chocolate bars formed container, after which express produced tasting products. As a result of tasting it becomes clear whether deviates significantly from the standard chocolate, and it avoids the formation and packaging of a product that will eventually be discarded.
The controllers responsible for verifying the weight and appearance of products, can also perform periodic tastings, but they do not take decisions on culling, but only warn about possible violations.
weight control[*]
The production of overweight products naturally affects profits, and making a large number of products with a weight below the nominal is a deception of consumers and a violation of the law. Hence the need to organize a system for controlling the mass of products. Some enterprises use cards of the "less-than" type with a zero line representing the nominal (correct) mass. The integers on the map, denoting grams, depend on the type of product. On the mass distribution map, the controller can quickly get an idea of ​​how the masses of the products are distributed - if there is a shift towards the upper control limit, the operators perform the appropriate adjustments towards a decrease in mass, and when there is a shift toward the lower control limit, Increase.
The distribution curve makes it possible to determine the average mass that is put in the prime cost. In addition, it shows the characteristics of the installation and points to points where enhanced monitoring is required. This curve allows the operator to determine when the situation is "out of control" and corrections need to be made to adjust. To obtain the distribution curve, and on the basis of the calibration chart, an appropriate sampling is necessary. If, as a result of the analysis of the samples, a bell-shaped curve (the normal distribution law) is not obtained, then the process is out of control. When receiving a bell-shaped curve, the lower line corresponding to the root-mean-square deviation is the lower control limit, and the upper line is the upper limit (a). The method used to prepare the verification charts and distribution maps is described below.
The mass of patisserie bars for some time (usually 8-hour shift) is entered into the table according to the verification chart (Fig. 23.3). Then find the sum for each column and for each horizontal line (for example, one bar weighing 0,82 ounces, four - 0,81 ounces, 23 - 0,75 ounces, etc., in Figure 23.2 only 4 h is reflected). Based on the data thus obtained, a distribution graph is constructed (Fig. 23.3). The frequency / is the number of different values ​​for weighing. Since it was assumed that 0,75 ounces is the average value of mass, then for two eight-hour shifts this group was given the name zero (0). Masses greater than 0,75 ounces are marked with positive numbers (+), for example, 1, 2, 3, etc., and masses less than 0,75 ounces are denoted by negative numbers (-) - for example, -1, -2, -3, etc. Such designations help simplify calculations.
23.3 Fig. 23.3. distribution map mass confectionery bars
Frequency ƒMultiplied by the class of deviation (mark + or -) gives a certain value ƒd. Multiplication ƒd by d gives ƒd2.
The formula for standard deviation (a) has the form
where A - the actual interval for the group (in the above example - 1), and n - number of samples or sum frequency.
The standard deviation (a) is the most important measure of the mass dispersion. It determines how large the deviations in the samples are - the greater the value of the standard deviation, the less grouped the samples. What do you mean, when they say that the standard deviation of the bars is 3,04? This means that the bars differ in weight - some were higher and some below average. The root-mean-square (standard) deviation is equal to the square root of the variance. When the resulting mass distribution makes it possible to construct a normal bell-shaped curve, the standard deviation is related to the mean. Between 1 and + 1 (72,3 and 78,4) 68,3% of bars should fall, between 2 and 2 (69,3 and 81,4) 95,3% of bars should fall, and between a3 and 3 66,3 (84,5 and 99,7) 3% of bars. The verification (control) card can not be created until the upper and lower control limits (confidence intervals) and the average mass have been determined. Such a map should be based on the distribution curve and on the data obtained on its basis. For the upper control limit, we must have a 84,5 or three standard deviations of 75,4 with an average mass of 66,3 and a lower control limit of 0,85, three standard deviations below the average. Thus, one item weighing 0,66 ounces and two others (one in 0,65 ounces and one in 0,48 ounces) is a marriage that extends beyond the confidence intervals, which is XNUMX%. The real masses of confectionery bars, measured in two eight-hour shifts, are shown in the following example.
These masses are kept in groups, after which the calculations (Table. 23.1) were performed.
23.1 Table. Masses of confectionery bars


















































































































G - group (weight up to 0,01 ounces); d - the deviation of the class; f - frequency
23.4Fig. 23.4. Checklist
It is assumed that the average mass equal to 75; 227, divided by 620, equal to 0,366. This value is added to the estimated average for the true mean 75,366.
Standard deviation (sigma) while still
Then you can build a control card for use in the production (Fig. 23.4).
In the production control weight measurements are performed every 15 minutes. On the map shown in Fig. 23.4, the estimated values ​​are marked by crosses (x). After 60 min measurements there is a clear bias towards weight reduction, requiring corrective action. On the basis of these checklists can be decided on the tolerance (as from a legal point of view and in terms of cost).
Shelf life - limits and tests
Over time, any food products are reduced in quality, and eventually there is a condition in which the product becomes unusable and can not be sold. The rate of deterioration in quality depends on a combination of factors such as storage temperature, composition, quality of the ingredients and the properties of the packaging material. It is necessary to evaluate the period called the shelf life of storage. This period represents the time after which the product stored at an average temperature and humidity for a given outlet point comes to a state where it can not be sold. Given the volatility of conditions in retail outlets, the assessment should establish the most stringent requirements.
When determining the shelf life of a product, it is necessary to consider both the storage time in the store and the conditions in which the product will be stored. If to speak about average values, at half of the sold products quality will be better than minimum established, and at half - it is worse. Therefore, certain reference points are used: "90%" of two distributions (that only 10% of all products are exposed to the worst conditions at the outlet and 10% will be stored longer). This procedure ensures that approximately 98% of the products are of better quality than the specified minimum value.
Many products, including confectionery products, labeling currently indicating "pass to ...". Some indicated shelf life may be considered too optimistic - to maintain the high quality products for over a year requires the ideal storage conditions and packaging.
It is desirable to have the composition of the product with a low water activity without bystropor- inated ingredients (such as some dairy products, egg white, some fats and natural taste, aromatic additives).
To determine the true value of maximum shelf life required prolonged storage test under conditions typical for the average retail outlet, which is time consuming and is usually used only to verify the results obtained with the help of accelerated tests.
Accelerated tests for shelf life are performed using the following method. Take representative samples of the tested product and conduct their tasting. The samples are then subjected to different storage conditions (if possible in several types of packaging), depending on the properties of the product, after which the samples are again tasted at appropriate intervals. All tastings are carried out by a commission of experts, and the samples are evaluated on the scale of the sales opportunity. For testing, storage rooms with a temperature controlled by a thermal relay or large incubators are used. Preferably, the temperatures are 18,23, 27 and 29,5 ° C. Samples are usually checked after exposure to these temperatures for one and two months. Samples in incubators at temperatures 27 and 29,5 ° C without special moisture control are usually tested in drier conditions than real ones. When evaluating the results, this is taken into account.
And others have also been developed test procedures for special storage conditions such as:
in tropical conditions 29 ° C, relative vlazhnost85-90%;
in cold storage conditions 7 and 10 ° C
frozen -7 ° C
Storage at low temperatures requires special comment. While such temperatures allow to preserve flavor, chocolate coated confectionery bars with waffles, a porous body or other similar fillers when stored under conditions of very low temperatures, crack and sometimes break. Especially not tolerate such storage products with a milk chocolate coating.
breaking testing
In some confectioneries, samples are sometimes exposed to varying temperatures and humidity. The maximum and minimum conditions often mimic the most severe tropical conditions. For example, the temperature changes every 24 h from 15,5 to 32 ° C, and the relative humidity can increase to 85-90%. Such a method of accelerated testing can often be misleading, and they should not replace the above-mentioned tests in incubators. It may be of some value for packaging testing, but it should never be applied to unpackaged confectionery.
Specific conditions necessary for accelerated shelf life tests, vary by product, region and type of sale retail outlet (shop, supermarket, kiosk). These conditions shall be determined by the quality inspector in cooperation with the marketing department.
For the analysis of the test results of shelf life can be used method of slope (relative slope of the curve), which evaluates the damage rate, is used to compare types of packaging or storage conditions.
23.5 Fig. 23.5. Changing the quality of products under different conditions and duration of storage
Some experimental data are shown in Fig. 23.5. Four straight lines correspond to the four different combinations of storage conditions. It is assumed that the starting products are fresh (L); starting from this point, damage develops linearly at a rate depending on the packaging and storage conditions.
When using the angular coefficient method, a mathematical model is used, which is an accurate description of this process. In practice, it is not assumed that the results will exactly match it. Influence on the results may be several factors - a mistake in tasting, unstable storage conditions or heterogeneity of products, but it is assumed that the model corresponds to data within certain limits, estimated by the statistical criterion. Therefore, a number of different tests are applied to a specific data set to determine the applicability of this model to available data. On the basis of tasting, a series of curves is usually constructed, and on their basis, the angular coefficients (the value of the average slopes of the curve) are obtained, which allow estimating the limits of shelf life.
Control of microbiological quality
Microbiological issues are discussed in detail in the relevant sections. The need for microbiological control is determined mainly by the following objectives:
  • prevent the presence in the products of pathogens;
  • preventing bacterial spoilage of products.
Infection may be due to:
  • with purchased raw materials;
  • with the growth of microorganisms during processing;
  • with mishandling the finished product or the unsatisfactory storage.
It should also be taken into account that despite the microbiological contamination, the finished product can be quite satisfactory to taste and appearance. Nevertheless, the microorganisms present under suitable conditions (human body, warm moist conditions during the subsequent cooking) will multiply rapidly. Unlike meat, fish and other perishable foods in most confectionery products, microorganisms remain in stable form at ambient temperature because of low water activity and high concentration of the liquid phase of the syrup.
Microbiologist Company is primarily responsible for ensuring that the raw materials have been reported to the company clean of pathogens. In the past, salmonella was found in coconuts, some dairy products and egg whites, and mycotoxins - in peanuts and various spices.
Microbiological control of raw materials for confectionery production should show a lack of raw materials 1 g Salmonella, E. coli (Escherichia coli) and intestinal bacteria (Enterobacteriaceae). The presence of the last two microorganisms indicates unsanitary food preparation.
The presence of microorganisms that cause spoilage (rancidity, fermentation, flavor defects), molds and yeasts to be at a low level (for example, the total content of CFU should be less than 5000, and mold and yeast - no more than 50 1 in the city
Some enzymes (especially lipase) confer confections higher fat soapy taste. The cocoa powder and egg white lipolytic activity must be negative.
Process Control
During most of the confectionery cooking processes all microorganisms are destroyed, but in the production of some pastes, sweets and aerated marshmallow and marshmallow products like this does not happen.
In microbiologically highly vulnerable such intermediate processes as soaking gelatin or egg protein, and therefore should be carefully monitored. The solutions must be freshly prepared, and the equipment and supplies used for the preparation of solutions should always be washed and sterilized.
With proper control of raw materials and production processes in the finished products must be microbiologically faultless. Some risks may be working with them in packaging and, in addition, there is always a chance of getting into the product contaminated dust microorganisms, and therefore the final product must always be checked selectively (that can perform the function of a kind of dual control of raw materials and the manufacturing process).
Another aspect of microbiological control is the study of customer claims, which all manufacturers hope to avoid. Nevertheless, there are claims (in the confectionery industry claims related to microbiological reasons may concern fermentation, rancidity or the presence of foreign flavors, and sometimes microbiological dilution). The latter defect can promote mold growth. When analyzing the samples that served as a reason for presenting a claim, the cause of the microbiological contamination of the product should be identified - it may be a mistake in the recipe or a malfunction in the process control system.
Sanitary condition, food poisoning and the presence of foreign bodies
Author's Note. Much of the information in this chapter is based on the experience and practice of the UK, but we hope that it will benefit both readers from other countries. Due to differences in climate and more population problems in other countries may be even more serious, but the knowledge of the general quality control methods, including hygienic measures necessary everywhere.
Some parts of this section are based on publications of the well-known UK chain stores system «Marks & Spencer» - Hygienic Food Handling ( «Methods of hygienic handling of food") and Hygiene in Marks and Spencer Staff Kitchen and Dining Rooms ( «Health in canteens and premises for preparation of food, "Marks & Spencer" ").
In humans, there is no "hygienic instinct", and people historically regarded health care that arose from ignorance and sheer neglect. Until now, the attitude of many to sanitation and hygiene, unfortunately, exasperated sanepidnadzora employees, and to maintain at a food facility necessary sanitary standards required constant pressure on managers and staff.
Here is a story related to the rural West of England and the characteristic attitude towards sanitation and hygiene in some parts of the developed countries.
The traveler, who wants to escape from the urban civilization among the rural beauty and quiet location, removed one of the farms (residents earned money by letting housing for rent).
Arriving tired late at night, the traveler went to bed. Getting up early in the morning, he walked around the house in search of a toilet and, not finding it, asked a relevant question worked in the yard man.
Closet, sir, there, behind the trees.
Our guest, finding "convenience", and returned again met in the courtyard of the same employee.
Found, sir?
Yes, but there are hundreds of fat black flies!
A fly, sir ... Yes ... You should have to go through half an hour, then they would be in the kitchen!
Historical background
At certain periods of the history of civilization (for example, the Babylonians and the Romans) related to health in line with the best modern standards, although old and did not understand the true causes of diseases and ailments.
After the Romans conquered Europe and the resettlement of people in the city, where the water was dirty, it was not enough, there was no sewage system, and the products were often corrupt, hygiene standards have fallen to very low levels. Such conditions prevailed over 1000 years, and is therefore not surprising that the rampant plague, cholera and other epidemics. The nature of these diseases in those days was not known - it was believed that they work of the devil and other supernatural beings.
The modern understanding of hygiene and sanitation appeared little more than 100 years ago, although the opening of the "germs" Dutchman Leeuwenhoek (1632-1723) gave rise to a general interest in finding a variety of causes of disease.
You can call the great names associated with this area: Louis Pasteur (1822-1895) made the discoveries that led to the creation of the famous Scottish surgeon Joseph Lister (1827-1912) antiseptic surgery. Robert Koch (1843-1910) tied some diseases with certain microorganisms and discovered the bacillus that causes tuberculosis. Austrian obstetrician Semmelweis (1818-1865) discovered the cause of puerperal infection, causes more deaths in childbirth.
By the middle of the XIX century. Medicine has made significant development, but a significant reduction in the incidence occurred only after major social changes.
Living conditions in the industrial regions, has developed rapidly in the beginning of the XIX century., Were just awful that 1830-ies, along with cholera epidemics. was the reason for calling for the improvement of the sanitary legislation. In the UK, the names of Sir Edwin Chadwick (1801-1890) and Sir John Simon (1816-1904) went down in history thanks to their work, which laid the foundation for the development of public health. Thanks to their efforts in 1875, was established by the Council for Health and the Law on public health.
Along with poor living conditions, society had to tolerate low-quality food, and this situation could not be corrected until science was able to provide satisfactory control and analysis. The Food and Drug Law, published in the UK at 1875, has the responsibility for ensuring that food is of high quality, entrusted to local authorities, and eventually certain standards have been implemented. Special attention was paid to milk and dairy products, as it was shown that they were the main reason for the spread of infections.
The application of the law by local courts, supported by effective work of analytical chemists, has made a huge contribution to improving food quality, and the law on public health (Public Health Act) gave the right to destroy unsafe products.
Over time and with changes in production methods in the food industry and cooking methods, it became clear that the original version of the law is not sufficient, however, before the advent of stricter legislation passed 60 years.
The law on public health in the UK, the 1936 and laws on food and medicines 1938,1944 and 1950 years. great attention was paid to the hygienic conditions in the premises used for the storage and preparation of food, conditions of transport, and, most importantly, issues of personal hygiene of staff.
In the United States to protect the public from the dangers that threaten the health, adopted federal laws and state laws and local laws.
Here you can quote the Federal Law on Food, Medicine and Cosmetics 1938, section 402. It states that a food product must be considered spoiled if "... it is wholly or partly composed of any contaminated, rotten or spoiled substance, or otherwise unsuitable as a food; If it was prepared, packaged or stored under unsanitary conditions, so that it could become contaminated, or be considered harmful to health; If it is obtained from a sick animal; If it is in a container contaminated with a hazardous substance ... ", etc.
Another aspect which arose after food hygiene (if you can call hygiene) refers to food additives, introduced deliberately or caught in a food product by accident. To increase the shelf life of the food product or to prevent the development of bad odor and taste to it can be added preservatives, some of the components were previously used are hazardous to health.
food poisoning
Most cases of food poisoning in recent years due to bacterial factors, although marked and cases of food contamination by chemicals. Food products currently produced and prepared in large quantities. Widespread public catering system, which means an increase in the likelihood that contaminated products will have an impact on a larger number of people.
Food poisoning is usually caused by one or two types of bacteria - salmonella and staphylococcus. Both of these microorganisms can cause severe inflammation of the gastrointestinal tract, accompanied by vomiting, diarrhea, pain in the stomach area and severe weakness.
The extent of poisoning may be different - from mild to severe ailments of the disease until death. There is also the possibility of chronic diseases due to prolonged consumption even slightly contaminated food.
It should also be mentioned microorganisms which, although not directly related to confectionery, can sometimes cause cross-contamination.
From time to time there have been serious outbreaks of botulism, sometimes leading to death. The cause is invariably poorly cooked food that was stored for some time, and then consumed cold. Particularly vulnerable in this sense home-cooked vegetables, if insufficient heat treatment carried out (requires their sterilization in an autoclave). Precaution fruit is the use of low pH.
These organisms are present in the feces of animals, insects and humans. Contamination of food is the result of inadequate sanitary measures in poor preparation and storage.
This microorganism, once common only in the Far East, are now spread throughout the world. As a rule, it is associated with infection with the consumption of raw fish.
In earlier times, failure to comply with sanitary and hygiene measures when working with food led to the emergence of serious infectious diseases - typhoid, cholera and tuberculosis, but the improvement of production methods, the use of clean water and more modern equipment of toilets at the food enterprises virtually eliminate this problem. An important factor in the prevention of contamination of food remains the fight against insects and rodents (see. 21 chapter).
In plants treated confectionery product usually has a low moisture content, which does not promote bacterial growth. So here the requirements for sanitary-hygienic measures may be somewhat lower than in the enterprise where they work with milk, eggs, or meat products (where poor hygienic conditions are the major cause of loss of product, and to the rapid growth of any microorganisms present in the products).
At the confectionery enterprise, however, there are intermediate products and ingredients in which harmful microorganisms can be present or which can promote the growth of microorganisms causing food poisoning. First of all, these are dairy products, egg white, gelatin, nuts and some dried fruits. Eggs, milk and gelatin before being introduced into the confectionery mass are usually transferred to solutions, which are sometimes left in warm places, where microorganisms can quickly and intensively multiply. Fortunately, these solutions are usually added at temperatures high enough to kill microorganisms, but they can get into the hands of the personnel. In addition, sometimes equipment for working with bulk products before being fed to the forming and cutting equipment is used without proper washing and cleaning.
During certain processes microorganisms are not destroyed. If you have used an ingredient contaminated with microorganisms or the confectionery mass is transferred via contaminated supplies, the paste, marzipan and chocolate after manufacturing can remain infected. Because of the low moisture content in these products, they do not contribute to proliferation of microorganisms, but when consumed by the rapid multiplication of microorganisms in the digestive tract, they can cause disease.
In favorable conditions micro-organisms that cause food poisoning multiply with great speed - for example, in humid conditions at 38 12 ° C per hour the number of bacteria can increase in times 100 LLC.
Sanitary conditions in the enterprise
At any food company to maintain good sanitation and hygiene cal conditions it depends on several factors:
  • staff;
  • Ingredients;
  • equipment and facilities;
  • fight against insects and rodents.
Staff. If employees are not familiar with the basics of hygiene, then the choice of the best ingredients, equipment and facilities is useless. Responsibility for personal hygiene lies mainly with the medical staff. After a medical examination confirming that a person can work with food, he should receive appropriate instruction in the field of personal hygiene - clean hands, overalls, headgear, use of toilets and inform the master about the diseases, especially the digestive tract. For such instruction, new workers and artists often use films and interviews.
Food ingredients. Raw materials shall be prohibited to take your bare hands. Unfortunately, confectionery companies often violate this rule, but it should make every effort that the staff used to work with the raw material buckets and shovels, and to work with ready-made products - gloves. Dust from the raw material should not settle on the finished product.
Premises and equipment. Most often they do not work neatly in an untidy room. Maintenance of cleanliness is the responsibility of the person responsible for each room. It is necessary to regularly clean the equipment with jets of hot water and steam, it should be suitable for sterilization; A sufficient number of backup equipment should also be provided so that the equipment can be handled in turn. Damaged equipment must not be used. In addition to the washing equipment, a separate room for washing and sterilizing large equipment, bins and carts must be provided in each division. Disinfectants should be used cautiously, since many of them have a characteristic persistent smell.
Insects and rodents.
Storage. The standard of cleanliness of premises used for the storage of raw materials and finished products should be very high. An important feature here is the right inventory turnover.
Prevention of pollution by foreign bodies
For the reputation of the food products is very harmful litigation on claims of consumers related to the discovery of the product in the screws, pieces of metal or glass. Even more unpleasant for the consumer discovery in hair products, flies or excrement of rodents. Preventing the spread of all kinds of foreign bodies depends on the health of the enterprise. Below we look at the basic precautions that should be taken at all stages of production.
The use of a raw material in the company authorizes the laboratory of dealing with the control of its quality. He checks that the composition of the technical conditions and the fact that he had acted raw materials clean and safe (carried out pollution control rodent and insect fragments). The analysis is performed by dissolving or screening, so that the result can identify any foreign objects - pieces of wires, nails, splinters or fibers of the bags.
Raw materials delivered in bags, wooden crates or cardboard boxes lined with paper, easily contaminated upon opening the container. Quality Control Service Representatives must ensure that the packages are handled correctly, and in non-smokers. Nuts, raisins, and other similar materials to remove the stones, shells, twigs and other foreign bodies require mechanical and manual sorting. There is a special equipment for separation and pnevmosortirovki materials based on density differences, such as stones and metals.
Electronic Sorting
This sorting method based on the principle of the removal of any object of inappropriate color, used for the nuts and beans. Each nut is tested individually, and by means of a photocell when passing down the chute defective nuts quickly rejected. This method has its limitations.
Through magnetic separation of raw or partially processed products recovered metallic foreign bodies - bolts, screws and other metal inclusions. This is especially important in the direction of the raw material for grinding or processing, where a large failure can occur due to metal impurities.
When using electromagnets necessary at short intervals to remove adhering metal, without releasing all the captured magnet back to the product.
Vibrating screens and meshes IN PIPELINES
When the processing comprises dissolving raw or processed to its elastic-plastic state (as in the preparation of the chocolate mass), sieving allows to remove foreign bodies. Modern separation equipment allows the use of a sieve with small diameter holes without reducing performance.
When the raw material of the emulsion or solution is prepared, for example, before boiling caramel syrup or cream fondant, they should be passed through filters (screens) is possible with most small diameter holes in accordance with the required performance. Chocolate mass can be passed through screens, in-line built on site directly before molding or enrobing. For this purpose, various sizes are available vibrating screens having good capacity even for viscous chocolate.
Grids in pipelines or enrobing machine molding equipment - this is the last chance to prevent accidental contact with the product or equipment pieces of metal parts.
Electronic metal detector and X-ray detectors
Whatever precautions are in process has been undertaken, some impurities still fall into finished products, and to identify and remove such items require additional funds.
Electronic metal detector - a device that can be positioned over the conveyor belt, defining with it the metal particles present on the conveyor belt extending in confectionery. In recent years, the sensitivity of metal detectors has been significantly enhanced, and now they are less responsive to noise that interfered with work and significantly reduced the effectiveness of these devices.
The modern metal detector has the shape of a bridge, located above the conveyor, along which bars, small candies or packaged boxes move. Directly under the bridge, a "uniform electromagnetic field" is formed, and the metal particle, passing through it, breaks the electromagnetic equilibrium, as a result of which an electrical impulse is generated, from which the alarm system is triggered. The signal can be given in the form of a light bulb or a bell, while devices that indicate the place on the conveyor where the product with the inclusion of the metal should be triggered are triggered. It is necessary that the responsible employee manually remove these products.
Much more reliable automatic sorting when the product with mechanical impurities are removed from the tape. The conveyor can be divided, with the pastry with the impurities are discharged into the container located at the bottom. The detectors can be fitted and piping - thus diverting from the detector is triggered the mechanism to remove contaminated product.
Basic principles of detection and rejection device shown in Fig. 23.6 and 23.7. The sensitivity of these devices is shown in the table in Fig. 23.6, is now possible to determine the presence of iron or ferromagnetic particles of stainless steel in packs of aluminum foil. The recording device records, for example, the presence of metal in the package of candy particles to 1,5 mm diameter. To achieve maximum sensitivity is recommended to have the moving package in a line.
Waste pastries can be checked individually by passing through the detector during a stoppage in production. In some companies this is done using a special detector. Sometimes metal parts
Window size (apartury)

Steel, iron, copper, brass, aluminum

The non-magnetic stainless steel



EN58J 316


101 mm

101 mm

0.5 mm

0,6 mm

0.7 mm

35-5 mm

101 mm

1.0 mm

1.2 mm

1.4 mm

762 mm

203 mm

2.0 mm

2.4 mm

2.8 mm

660 mm

355 mm

2.5 mm

3.0 mm

3.5 mm

The minimum diameter of the spherical shape detectable metal particles
17 Metalldetector 1
konveerniy metallodetektor 3Fig. 23.6. metal detector and sensitivity table Courtesy Lock Metal Detectors company, Oldham, Manchester, United Kingdom
equipment destroyed, and parts thereof fall unnoticed into the product batch. This can lead to the fact that in-line detector will be activated very often and more convenient to check a batch of products on the detector separately established.
Often it makes sense to separately examine the discarded product that allows you to identify the origin of the metal particles, if there is an unusually high number of contaminated products. To do this, make the pulp with hot water, which is passed through a sieve, allowing to remove the foreign objects. Search more complicated, if the product contains nuts or fruit, but usually thorough magnetic separation can detect foreign metallic inclusions (particles of ferrous metals are much more common than colored particles).
Frequent detection of metal particles with identical properties may be necessary to verify the semi-finished products or raw materials.
Magnetic separation and screening can not be used in some technological processes, and the metal particles thus fall into finished product. Examples are small pieces of wire found in dried coconut, and lead shot in raisins (for shooting birds in the vineyards).
23.7 Fig. 23.7. Typical automatic rejection with metal detectors:
Metal detectors are installed on conveyors, chutes and pipes, on the packaging and processing equipment or other equipment to work with the material in a stream to provide fully automatic control. When metal is detected the relay is triggered detector, an alarm and stops the drive of the conveyor, and includes an automatic ejection mechanism for culling
Published with permission Lock Metal Detectors, Oldham, Manchester, United Kingdom
X-ray detectors theoretically have the advantage that they can reveal stones, glass and other dense nonmetallic particles. The use of X-ray detectors in large enterprises is a very expensive and time-consuming procedure, and because of the human factor, the efficiency of the determination is relatively low. Since this method involves visual control on the screen, the control speed is small compared to the speed of the electronic detector. Regardless of the conscientiousness of the controller in a very short time, he gets tired, besides many particles on the screen have an unclear contour.
Coping with the control of hundreds of thousands of packages is very difficult, and even semi-action system is usually unprofitable. The best solution seems fully automatic X-ray detection system of foreign bodies.
Foreign inclusions that fall into the product from personal items, office supplies and small auxiliary equipment are a great danger. In the product during its preparation pins, hair clips, buttons, clips, etc., can get, and only personal accuracy and strict control can prevent this. Despite the ban on smoking in production facilities, even cigarette butts and matches sometimes fall into the product, which can bring to the production areas on the soles of shoes. Use of clips, brackets, clerical or drawing buttons in production areas should be prohibited. If the production staff is provided with the required equipment, the need for personal penknives and similar small tools is eliminated, although the products have even found pieces of razor blades that the adjusters used for some of their purposes.
The production area is prohibited to bring food and drink (in most enterprises operating near a room where you can eat).
The reason for falling into glass products are most often broken windows or light bulbs. About all the broken or cracked panes should be promptly inform the management, and must be communicated immediately replaced. All electric lighting in rooms with bulk products must be protected.
Can not be ignored and the probability of malice. Sometimes employees because of dissatisfaction, management or for political reasons, may wish to enter a specially dangerous objects or substances in the product (such cases are known from press reports). In large companies usually have a medical unit, and to identify potentially unbalanced employees need a psychologist.
Monitor sanitary conditions
For effective implementation of the measures required of senior management's interest described above. Managers should perform periodic inspections without warning. Detailed survey carried out sanitary doctor and his staff. Their tasks include the control of insect and rodent control, the organization of the selection of equipment swabs for the presence of pathogenic microorganisms. Management is required to maintain sanitary doctor, since no other approach does not provide adequate control.
transportation test
Protective packaging quality for the type of packaging material and sealing method has been discussed in the relevant sections.
Often do not pay adequate attention to the construction group packaging (cardboard box, box). For information on the strength of such packaging to protect products during transportation and storage should provide the quality control department.
Some firms are transported batch of finished products from production plants to warehouses on pallets. Warehouses can be located in different parts of the country, in areas with road transport. From cargo on pallets in warehouses and then form a party on individual orders for delivery to wholesalers and retailers.
Other companies send products directly from factories to retailers in boxes made of corrugated cardboard, using public transport or other rented. The strength of boxes with the products should be sufficient to support the weight set top boxes. For loads on pallets, which are transported by trucks or vans, it has been found that the conduit must withstand pressure equivalent to the weight of the total of five boxes mounted on. This pressure can be calculated from the height of the cargo 1-1,5 m.
To test the boxes use a laboratory hydraulic press {Carver Laboratory Press), equipped with flat plates. The test box is placed between the plates, and the plates are gradually shifted, evenly applying hydraulic pressure, which is continuously recorded by the instrument. The pressure at which the box just begins to break down is recorded. With the help of this device it is possible to test boxes of different design and from different cardboard, with or without internal spacers. The required strength is affected by the type of confectionery in the box. For example, solid chocolate blocks, tightly packed in a box, can withstand considerable weight without damage, whereas in the case of transportation of assorted sets with soft fillings or marshmallows, the group container (box) should assume the entire load.
Unfortunately, the staff is extremely careless - in warehouses there are cases of picking too high stacks, in which the lower boxes are squeezed to half their normal size! Although the load test provides information for selecting the desired box (box), the final answer is given by transport or model tests. For this, cargoes are prepared on pallets or in cardboard boxes and cross-country vehicles are sent to several wholesale warehouses, where they are examined upon arrival.
For transport tests, there is a special complex equipment simulating the movement of the load and the pressure that can occur during transport, but the results obtained in this way should be approached with some caution.
  1. Birch, GG, and Parker, KJ Control of Food Quality and Food Analysis. - Barking, England: Elsevier Publishers, 1984.
  2. Butcher, DW On-line Monitoring of Continuous Process Plant. Ed. Dagenham, England: North East London Polytechnic. 1983.
  3. Gould, WA Food Quality Assurance. - Westport, Conn .: AVI Publishing Co., 1977.
  4. Quality control in the food industry conference papers / Institute of Quality Assurance, UK (Conference Communications). - Farnham, Surrey, England: Holly Tree House. 1974.
  5. Kramer, A., and Twigg, BA Quality Control for the Food Industry. - Westport, Conn .: AVI Publishing Co., 1970.
  6. McFarlane, I. Automatic Control of Food Manufacturing Processes. - Barking, England: Elsevier Publishers, 1983.
  7. Pearson, ES, and Hartley, HO Biometric Tables for Statisticians. Cambridge University Press, London.
  8. Steiner, EH Statistical Methods of Quality Control. - London: Academic Press, 1967.
  9. Stiles, EM Handbook of Total Quality Assurance. - Englewood Cliffs, NJ: Prentice-Hall, 1968.

[*] The section on mass control is based on a presentation on quality control at the University of Wisconsin as part of the course of the National Confectionery AssociationNCA), Made by the late Wesley Childs ( WesleyChilds), Working in the company CurtisCandy. - Note. Aut.
Last modified on Friday, November 06 2015 15: 46
Vladimir Zanizdra

Founder Baker-Group.net site. More than 25-years of experience in the confectionery industry. More than 20-five years of management experience. Experience in the organization and design of the production from scratch. Site: baker-group.net/contacts.html El. mail This e-mail address is protected from spam bots. You need JavaScript enabled to view.

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