Chemical preservation of fruit and berry puree.

This method of preserving fruit and berry puree is most common in practice.

It lies in the fact that it introduces chemical agents (preservatives) that act bactericidal on the microorganisms of this medium at the dosage of them in small quantities. The main requirements for preservatives for fruit and berry puree are as follows: harmless to the human body in the doses used, chemical stability, i e. Unchanged chemical composition of the preservative throughout its duration, non-volatility and chemical indifference to the puree itself. It is necessary that the preservative had no effect on taste, color and jelly - forming ability of mashed potatoes and that it has good solubility in water.

There are a large number of chemical preservatives, which are used in the food industry. Of these, for apple puree used in various countries: benzoic, sulfurous, (formic acid, salicylic acid, the latter isomers, salts of these acids, and others.

In Ukraine, allowed to be used for fruit and berry puree, only two preservatives: benzoic acid and sulfurous acid.

Byenzoinaya kislota (C6Н5COOH) is a universal preservative for a number of food products (fruits, meat, eggs, etc.). Particularly strong bactericidal effect of benzoic acid and its compounds are in media with a low content of nitrogenous substances and with a clear acidic reaction. The most suitable for preserving it are products having a pH within 2,5-3,5. Benzoic acid has a preservative effect, directed mainly against yeast. It follows that it is suitable as a preservative for apple puree, since the latter has a relatively high acidity and a low content of nitrogenous substances. The dosage of benzoic acid necessary for canning can be varied within 0,05-0,10% depending on the natural acidity (pH) of the apple puree: when working with acidic puree, you can take the maximum dosage of the preservative and vice versa.

Benzoic acid and its compounds impart a light sauce sugary-tart flavor. At the canning within the dosage not exceeding 0,1%, the flavor of benzoic acid is not felt.

Benzoic acid is poisonous, but getting into the human body in small doses, it does not stay in it. React with glycine in the body it is converted to hippuric acid11.1

This reaction develops in kidneys where a preservative as hippuric acid excreted.

Limits for the content of benzoic acid in the finished product marmalade-Pastila production to establish the Ministry of Health Academic Medical Council is 0,07%. For the applesauce, this rule is 0,10%.

Benzoic acid and low-volatile compounds, which makes it possible to use them for preserving puree both hot and cold in hermetically apparatus.

Due to the poor solubility of benzoic acid in water are usually used for preserving its mashed soluble sodium salt (sodium benzoate) or an ammonium salt (ammonium benzoate). The sour mash, which is available a sufficient number of free acid stronger than benzoic acid, the latter is released from the benzoate.

If applesauce slightly acid, sometimes there is a browning sauce for canning sodium benzoate. Thus there is a neutralization of the acid and a significant pH offset undesirable for studneobrazovaniya, taste and firmness puree. In these cases, a beneficial use of free benzoic acid or artificial acidification of mashed food acid.

To enhance the action against mold benzoic acid use it is sometimes mixed with food acids or sulfurous acid. Benzoic acid is often used in the form of esters of benzoic acid or its mixtures with its derivatives, which have high bactericidal action. These drugs are known abroad under the name "mikrobin" (sodium salt parahlorbenzoynoy acid C6Н4S1SOShe"Nipakombin" (mixture 2 parts benzoic acid ethyl ester and propyl ester 4 parts of the same acid) and others. There are formulations representing combinations of sulfur and benzoic acids.

Technology preservation sodium benzoate is as follows.

Prepare 10% ethyl or ethyl benzoynonatrievoy 20% salt solution in a hot (70-80 °) water. The solution was filtered or filtered and then added to the hot stirred with mashed them with a mechanical stirrer or by hand. It is important that this has been achieved by uniform distribution throughout the preservative puree mass. The amount of preservative solution is taken from the corresponding calculation to provide a concentration of benzoic acid in sauce within 0,07-0,10%.

When using the free benzoic acid is necessary to convert the latter into sodium benzoate by treatment with soda. To convert the benzoic acid to sodium bicarbonate of soda used. It is necessary to take a chemically pure drugs with known content of C6Н5SOON i Nansi3 by the reaction equation:11.2

Sulfurous acid H2S03 is more potent preservative than benzoic acid. It exerts its bactericidal action and against yeast and molds against. Thanks to its regenerating effect sulfurous acid helps to preserve color and antiscorbutic properties canned puree.

With these positive properties of sulphurous acid is more harmful to humans than benzoic acid, as it is a cumulative poison, which, as its consumption is accumulated in the body. In this connection, sanitary legislation strictly limits the permissible residual content of the preservative in the finished product. According to our existing health statutes that rule is limited in the amount of not more than 20 mg (in terms of free S02) And not higher 100 mg total S02 on 1 kg jellies and pastes, t. e., respectively, in the range of up to 0,002 0,01% and% to the weight of the finished product.

Cooking ready confectionery semi-finished products it is usually accompanied by the removal of sulfur dioxide. Sulfited puree, particularly in the production of pastes, is pre desulfitatsii before churning it with sugar.

Disadvantages of sulfuric acid as a preservative are also in the fact that it is fragile and volatile. During long-term storage of puree, preserved with sulfuric acid, the latter part is oxidized to sulfuric acid, while part of it forms other sulfur compounds when interacting with sugars and other organic substances. Due to this, the preservative effect of sulfurous acid decreases with time. The attenuation of the action of sulfuric acid is also possible due to the volatilization of part of it during storage through the leakage of the container. Due to its volatility and partial separation in the processes of preservation, secondary wiping and knocking down sulphurous anhydride significantly worsens working conditions.

A disadvantage of sulfurous acid as a preservative is the fact that it causes corrosion of metal parts of the apparatus.

Despite these negative properties of sulphurous acid, it allowed for the preservation of fruit and berry puree in the absence of other preservatives. In the presence of benzoic acid and its preparations should be primarily to use them.

For the preservation of fruit and berry puree sulfurous acid is used in the form of 6-7% aqueous solution of 100% or bottled gas. Calculating the amount of preservative is conducted on the basis of the amount of mashed potatoes, the working concentration of sulfurous acid and dosage 0,10-0,12% $ 0? mashed by weight. Usually take the solution in several more considering possible B02 losses due to volatilization. Sulfur dioxide is dosed directly from cylinders on the net weight change cylinder, lying on the scales.

Sulfur dioxide is one of the gases whose solubility is greatly reduced with increasing temperature. In this connection, typically provided compulsory cooling fruit and berry puree into it prior to introduction of sulphurous acid.

Special cooling devices enables fast and quench puree until 10-15 temperature °, ie. E. To a temperature that is not hazardous to the development of yeast in it.

The study VKNII [13] was theoretically grounded and practically tested the possibility of preservation of sulfurous acid apple sauce hot without prior cooling of the latter.

These solubility S02 show that the saturation concentration S02 in water at 100 ° is about 0,1%, t. e. dosage corresponds S02Adopted for preserving purees. Due -c adsorbability pectins and other colloids included in the mash, it can be expected that the number 302, puree retained at high temperatures will be higher than in pure water.

In accordance with the law of Henry Dalton solubility of sulfur dioxide in the hot sauce can be greatly improved by increasing the partial pressure S02 in the space above the surface of the canned puree. In practice, this condition is carried out by dissolving and stirring a hot soup with S02 in hermetically sealed mixers. Good results in terms of minimum loss of preservative are obtained by mixing hot sauce with a preservative at temperatures no higher than 70-75 °.

In order to better preserve studneobrazuyuschey mashed capacity during sulfitation advisable to pre-cool it to 50-55 °.

The process of pre-cooling of apple puree and subsequent sulfitation it in an airtight unit is carried out in a continuously operating system installation of the Krasnodar branch of the Central Research Institute of the canning industry (Fig. 8).

The device consists of a vacuum receiver 1, which serves to pre-cool the puree. The latter is continuously sucked into the vacuum receiver, in which the vacuum 500-600 mm Hg is maintained. Art. In this case, the puree is cooled to 55 60 ° and somewhat thickens by self-evaporation. The second discharge port of the vacuum cleaner is pumped out continuously with the 2 plunger pump, driven by the 7 drive, pumped into the 4 sulfidator which is a 5 water jacketed cylinder and a 8 paddle stirrer -9. In the sulfitator saturation of mashed potatoes with sulfur dioxide and additional cooling of the mixture at 5-10 °. Sulfuric anhydride enters the sulphurator in the form of 100% S02, T. E directly from the cylinder through the 6 3 reducing valve.Continuously operating plant for canning fruit and berry puree.

Fig. 8. Continuously operating plant for canning fruit and berry puree.

With the last controlled feeding sulfitator gas in such a way that it is done with a pressure of about 0,4-0,5 atm and so that when mixed with the mashed їv gas for about two minutes the S02 mixture was 0,12-0,15%. Canned sauce continuously leaves the device through the pipe 10 pyureprovodu by handing it in storage tanks or barrels for transportation.

All parts of the plant in contact with mashed potatoes and S02, Made of corrosion-resistant materials.

Plant capacity of about 2 t / h on applesauce.

For small businesses are for this purpose constructed on the same principle hermetic sulfita- tori batch, in which specify a preservative in the form of bottled gas or as 6-7% aqueous solution.

In the latter case, there is some dilution of the mash water, which is undesirable, and therefore it is preferred to use sulfur dioxide dosed directly from cylinders.

Work with S02 should be possible under the eaves, t. e. in the open air or in rooms with special ventilation.

Workers who come into contact directly with a preservative (who make the working solution S02, Caring for gas cylinders and so forth.), You must use masks.

Canned sauce that is put into storage tanks should be immediately, as the filling of them is sealed, filled barrels - immediately capped.

Recently, for the preservation of fruit and berry puree offered some new preservatives, of which it should be pointed propionic acid, sorbic acid and their compounds.

The great interest in this respect is an unsaturated fatty acid - sorbic acid CH3-CH = CH-CH = CH-COOH. There are a number of reports that it reliably protects many food environments, including fruit and berry puree from the fermentation and growth of molds. It is more effective as a preservative than benzoic acid and said foreign taste products. The required dosage for its fruit and berry puree about 0,05%. According to reports, it is harmless; the lack of it - poor water solubility. Therefore, its use is practiced in a solution of propylene glycol in a concentration of about 5%.

Storage applesauce in transport and stationary containers

Companies that produce marmalade-Pastila products should be stored in a long-prepared for the future supply of fruit semi-finished products (applesauce, sulfited fruits, etc..).

Storage of fruit semi-finished products is an important step of the process in the production.

Canned applesauce for storing or sending, is poured into the barrels with a capacity of up to 100 200 l. Quality of drums has thus paramount. They must fully comply with the current conditions.

Prior to filling the barrels have to be thoroughly prepared for the purpose of pre-soaked in water to dirt, facilitate removal, for him, wet, and to stave swollen and compacted in the joints. After the soaking is necessary to wash drums with the help of special machines, wash them inside and out.

Then proshparivayut steam drums.

New barrels, not previously used, especially oak, must be subjected to pre-treatment 3- 5% -s' solution of soda to extract tannins timber, which may cause darkening of the puree. After treatment with soda barrel washed several times with pure cold water to completely remove the traces of alkali.

Old barrels not been processed with alkali, sulfur should be fumigated after scalding.

Proper preparation drum for receiving puree guarantees killing them foci of infection that could lead to contamination and spoilage puree.

Filling of barrels being approximately 0,9 their height, about 1 / 10 tank barrels is usually left unfilled, than to create a backup space in the barrel in the event of expansion due to the mashed zabrazhivaniya, warming or freezing.

Barrels of applesauce, canned sulfur dioxide immediately sealed at a temperature no higher than mashed 55-60 °.

If canned puree benzoic acid, its temperature at the time of capping the barrels should be no higher 45-50 °, since at a higher temperature may be some darkening of the pulp.

After capping the barrels with mashed them stand before shipment within 3-4 days under special surveillance in perhaps more cold place. The purpose of this exposure - to identify simultaneously with the progress of cooling mash barrel with defects or unstable puree.

The product of fermentation with signs or dokonservirovat necessary to resort to recycling.

After this test the barrel permanently sealed and secured to them hoops. On the upper bottom of the barrel is made in accordance with the labeling requirements of the standard.

Applesauce is stored in warehouses, isolated from the influence of external weather conditions. Optimal storage temperature 1-2 °.

Freezing applesauce undesirable since it necessitates a special defrosting puree before starting its production. The most favorable relative humidity 70-80%.

Barrels are stacked flat on 2, 3, 4, 5 rows horizontally or upright in 2-3 tiers vertically. Stacking barrels in tiers and tiers disassembly is facilitated by using special mechanical devices for lifting of barrels and drums perestilki tiers of wooden planks. In these cases, the barrels of mash can be stacked higher than in 2-3 tier.

Between piles or rows, in which the individual parties puree stacked along the walls and passages leave a width of about 0,75 m.

The required area under the given conditions (laying in 2 3-tier) on 1 t-mash of 1,3 1,6 m2.

Before laying in piles, each barrel of mash should be subjected to a thorough visual inspection.

The need for special monitoring of the airtight seal and removing the barrels from the warehouse of any remnants of mashed potatoes. This is important in order to deal with mashed pests. Of these, the most common so-called acetic fly, fly, or red (Drosophilla cellaris). It lays its larvae in the mashed potatoes and, in addition, is a carrier of yeast and acetic acid bacteria.

In winter, it is stored in the courtyard of apple sauce. However, during the winter the frozen applesauce after thawing should not be left for storage in warm conditions, since the multiplication of microorganisms in the thawed product is more intense than in the products of non-frozen.

During warmer months, the open storage of apple sauce is unacceptable.

In the absence of storage, storage of applesauce in barrels in the open air is possible in piles, provided that stacks are laid in winter in the snow or in ice and the entire collar is covered with an insulating layer to prevent the collar from warming up for the entire storage period. This method of storage guarantees almost completely from losses / valuable product due to the [14] perebrod and can be recommended for confectionery factories, and especially for jelly pastry shops in the regions of the northern and temperate regions of Ukraine.

To ensure the safety of the fermented mash, pledged long-term storage should contain sulfur dioxide at least 0,12-0,15% and sodium benzoate for at least 0,1% by weight of the puree.

If stored properly canned applesauce in strong casks losses from leakage, shrinkage or fermented have no place. However, in all the circumstances are known to absorb losses from the extractives mashed wood barrels. According VKNII [15] these losses absorbed in smaller barrels capacity 100, l make up to 0,4% by weight of the puree or about 4% by weight of dry matter puree.

In this connection is very important application of the insulating coating (paraffin, bakelite, enamel, varnish) on the inner surface of the barrels. Usually used for this purpose waxing them. When this molten paraffin applied to the inner surface of the thin layer, which closes the pores of the wood.

Preparation, filling, capping and uncorking of small barrels (with the capacity of 100-200 kg) require considerable labor costs. In view of this, for large volumes of production and consumption of apple puree, it is advisable to organize its storage in large tanks. On the inner surface of them should be coated, indifferent in chemical terms to the puree. Such tanks are widely used in the fruit-processing enterprises of the canning industry. The storage of mashed potatoes in large volumes is combined with mechanical pumping and non-stop (bulk) transportation of it. At the same time, the cost of packaging and its depreciation is sharply reduced, losses of puree are reduced during storage, the storage area is reduced, the cost of servicing the purées of storage is cheaper.

When storing apple (mashed necessary to carry out observations of changes in solids content in it. These observations must be accompanied by the control of microorganisms and preservative in the mashed potatoes.

Driving line production of fresh apple puree

Production of apple puree in large confectionery factories implemented in the form of production lines.

Below is a brief description of the production line production of apple puree Nalchik confectionery factory (Fig. 9). It provides stiffened apples shparitele Dmitrieva and preserving puree S02 by setting the Krasnodar branch of the Central Research Institute of the canning industry.

Apples are unloaded from boxes 1, weighed on scales 2. Then they are transferred to the inspection conveyor 3, on which the marriage is separated. The sorted apples are pre-washed in the 4 elevator and then in the 5 fan wash. The washed apples are lifted by the elevator 6 to the 7 scraper. Apples are unloaded from the bottom of the spar to the 10 wiper, and the condensate and sump from the crusher are collected into the 8 collector for use. Sprayed apples pass before rubbing through the 9 roller crusher for pre-grinding (the crushers are arranged in such a way as to avoid crushing the seeds). The mashed puree drains into the open collector 11, from where it is sucked into the vacuum receiver 12. The puree is pumped out of it by the 13 plunger pump into the 14 sulphurator, from which it continuously enters the reservoirs of the storage tank or is packaged in barrels.Driving line production puree from fresh apples.

Fig. 9. Driving line production puree from fresh apples.


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