The blended formulation apple-sugar mixture is directed as needed for cooking.
The main task of cooking the marmalade mass is to use gom to remove excess water and to create the ratios of pectin, sugar and acid that are most favorable for gelling.
In the process of cooking, the pectin substances of the fruit and berry puree are soluble, including the part that remains in undissolved form after the partial hydrolysis of the protopectin during the fruit crimping. However, the cooking conditions must be calculated in such a way as to prevent excessive splitting of pectic substances before breaking the polygalacturonic chain and obtaining degradation products that have lost the ability to gelatinous. In this regard, the most negative effect has a long cooking and high boiling point mass.
When cooking fruit and sugar mixture is a rapid and complete dissolution of sugar.
Important in the cooking process is the inversion of sucrose that develops under the effect of heat and organic fruit acids, residual sulfurous acid present in the mash as a preservative.
The presence of known amounts of invert sugar and other reducing substances in the marmalade mass is necessary. The reducing sugars play the role of an “anti-crystallizer” for sucrose.
The mechanism of action of reducing sugars in the marmalade mass as an anti-crystallizer, or a factor delaying the crystallization of sucrose, can be represented as follows. The sucrose content introduced into the formulation is about 65% by weight of the mass, which exceeds the saturation concentration of the aqueous solution of sucrose at room temperature. The substitution of a part of sucrose (granulated sugar) with products of its inversion during cooking leads to a decrease in the concentration of sucrose in the fruit-sugar mixture and to the elimination of the state of saturation (and supersaturation) of the sucrose solution.
It is also known that the joint presence of several sucrose in an aqueous solution contributes to an increase in the total amount of sugars; held in solution, which also reduces the risk of crystallization of the solution, in this case, the selection of sucrose in the solid phase. Meanwhile, excess invert sugar at low concentrations of sucrose in the composition of the fruit-sugar mass can also lead to saturation (and supersaturation) of the solution due to glucose, which has a weaker solubility compared to sucrose and fructose. In this case, it is possible to sugar the mass due to the crystallization of glucose.
The data of many studies and available experience show that when 14 is present in the marmalade mass — 16% of reducing substances, an equilibrium state is provided that virtually eliminates the crystallization of any sugar from this medium.
It should also be noted that the accumulation of invert sugar in the process of cooking above the specified norm leads to an increase in the hygroscopicity of the marmalade and reflects negatively on its persistence in storage.
When using applesauce with normal amount of acid produced in the process of cooking invert sugar does not exceed the required standards.
The increased accumulation of invert sugar mainly contributes to the duration of cooking. In view of this, it is necessary to achieve faster cooking, especially in the case of mashed potatoes with high acidity or highly sulfitated.
The VNII study indicated an effective means for controlling the inversion of sucrose when cooking marmalade mass in vacuum machines - regulating the degree of vacuum in the cooking space. Therefore, when cooking in vacuum machines, it is recommended to change the vacuum depending on the desired accumulation of invert sugar. It is quite obvious that if necessary, the inversion amplification should reduce the vacuum and vice versa.
In order to prevent excessive accumulation of invert sugar in the process of cooking marmalade mass (as well as in the subsequent process of marmalade drying), the introduction of alkaline or buffer salts to the prescription mixture has recently been practiced. However, the latter, when working with subacid puree, even with small dosages of these salts, lead to the necessity of introducing invert sugar into the marmalade mass from the outside in the form of invert syrup.
During cooking, marmalade mass of mashed potatoes, canned sulfurous acid, is also achieved by the removal of SO2 of boiled mass. Desulfitatsiya is successful when cooked mass in vacuum pans, especially if the latter are equipped with agitators.
On the other hand, in the cooking process also occurs volatilization of aromas, fruit and berry puree. To reduce the loss of volatile components of the raw material is necessary to avoid delaying the cooking.
When cooking fruit and sugar mass is determined by its willingness to as weight moisture.
The moisture of the mass to be boiled is controlled using a refractometer, which makes it possible to determine it within 1 — 2 minutes. up to 0,5%.
To control the degree of boiling mass is used as the thermometer showing the signaling or mass boiling point. cooking temperature control is precise enough boiling mass when operating in open or boilers in a vacuum apparatus, if the latter is maintained at the end of cooking the same vacuum.
For cooking marmalade mass in large enterprises are operating continuously coiled cookers; in a small package production are spherical or universal cooking vacuum tubes.
The continuous marmalade pulping process was developed and carried out at the Moscow confectionary factory "Udarnitsa" on the basis of research conducted by the VNIII and the factory team. For this purpose, the coil column of the caramel vacuum apparatus of the Yaroslavsky plant system (without a vacuum chamber) is adapted. An apple-sugar mixture with an initial moisture content of 43 — 45% is sent to the collection before the cooking plant. The feed coil of the brewing column is powered by a plunger pump, with which the prescription mixture can be adjusted.
The mixture is boiled in a coil under atmospheric pressure to a final moisture content of 31 —- 33%. The end of cooking can be controlled by a thermometer at the mass outlet. The duration of the mass in the coil is 1 — 2 min. temperature of the mass leaving the / coil, 106 — 108 °.
Cooked weight comes from the coil in the receiving cone, which acts as a steam trap, to release it from the vapor bubbles.
The productivity of one cooking column with a heating surface 7,5 м2 is about 6 g per shift for marmalade mass or 5,3 t for ready-made marmalade.
High productivity of continuous cooking of marmalade mass and short-term heating of the prescription mixture best solves the problem of preserving the gelatinous ability of pectin and regulating the inversion of sucrose. Continuous cooking allows for a deeper mashing of the mass without harming the pectin, as well as the natural taste and color of apple sauce, and creates the necessary conditions for (full automation of control and process control).
In small enterprises, they use a universal cooking vacuum apparatus for quick cooking of marmalade mass. Load (in the upper digester) apple-sugar mixture in an amount calculated for the mass yield of 25 - 40 kg.
The masses are boiled under pressure of heating steam 4 — 5 ati to the final moisture content 31 — 33% for 6 — 8 min.
Transfer the mass to the lower vacuum cup, in which the mass is additionally condensed to a moisture content of 29 — 31% for 1 — 2 min. The content of reducing substances in the welded mass 14 — 16%, the total duration of cooking is 7 — 10 min.
When using a spherical vacuum suction apparatus set up by 400 600 mm vacuum gauge. Heating steam pressure of not less than 4 ati.
Sucked from the collection mixer apple-sugar mixture in an amount to provide data at the end of cooking conditions for 12 min.
Processing (cutting) marmalade mass
At the end of cooking, the marmalade mass is sent to the collection mixer, mounted above the casting mechanism. Add dyes, flavoring substances (supplies or essences) according to the dosages established by the laboratory and mix thoroughly. Acid is added to the mixed mass, depending on the need (acidification.
The amount of added acid should be adjusted according to the directions on the basis of laboratory data pH marmalade mixture and the pH of applesauce.
In production, it is often practiced to inject a certain amount of sugar to the end or after the end of cooking. Such an order of work gives the producer additional means for controlling the moment of the formation of the ball. At the same time, part of the sugar required for the formation of the jelly is turned off from the charge for cooking the marmalade mass. This eliminates the premature loss of pectin gel from the marmalade mass (coagulation). Such danger arises at a time when the jujube mass, as a result of excessive condensation, creates the necessary sugar for the formation of the sugar, acid and pectin.
Premature gelatinization is very undesirable. It has the effect that the jelly formed right after the cooking with further manipulations (cutting the mass, mixing and pouring it) is destroyed and its restoration as a jelly without re-cooking is no longer possible.
Due to the fact that the introduction of the required amount of sugar is removed by the end of the cooking, is also achieved a reduction of marmalade mass temperature during cooking, as the mass is a boiling point depending on the sugar concentration.
To a large extent these difficulties are eliminated by passing a continuous cooking marmalade mass, as in a short circulation and rapid heating of a mixture of pectin hydrolysis prescription and sucrose inversion are minimized.
The marmalade mass after tinting and flavoring with a temperature of about 80 — 85 ° and humidity 30 — 31% is poured into forms using a casting mechanism located above the forming conveyor that carries marmalade forms. In order to avoid mashing of the mass, it is necessary to isolate the pipelines along its route to the hopper of the casting head. The latter is equipped with water heating, which allows the mass to be tempered in the range of 78 — 80 °, i.e., slightly above the gel point of the mixture (~ 70 °).
Moulds jelly manufactured from stainless steel, porcelain or ceramics.
In the absence of mechanical casting, the mass is poured manually into molds mounted on a conveyor or on tables. For this purpose, use special stainless steel funnels with one or more drain holes. When working with periodically operating cookers, it is necessary to calculate the work so that the pouring of the mass from each boiler lasts no more than 10 minutes, or it is necessary to insulate the walls of the collector into which the mass is drained in order to avoid sticking it out.
The beginning of the gelation of apple pectin under these conditions, i.e., with the content of 1% pectin and about 65% sugar, occurs at a temperature of 70 °. If the hot mass is poured into molds before it has cooled to the specified temperature, then it is poured freely and easily. Otherwise, the mass partially zasudnevaet, loses the ability to flow freely from the funnel and poorly molded.
Process jam Sadki
The marmalade mass in the molds quickly cools, mainly as a result of contact with the cold walls of the mold cells. Under these conditions, the temperature of the marmalade decreases during 4 — 6 min. to 60 — 70 °, that is, it reaches the point of gelation of pectin.
The process of gelling is in production practice the name of the "cages" of marmalade. The cooling of marmalade is accompanied by an increase in the degree of supersaturation of the marmalade mass with sugar. Due to the strong dehydrating effect of excess sugar, the jelly framework is formed quickly. The latter gradually grows stronger and stronger. After some time, marmalade jelly is easily removed from the mold, amenable to cutting with a knife, etc.
The actual set-up process usually ends within 10 minutes. Thus, the residence time of marmalade in the forms is about 15 min. The duration of the set is important for production, since the turnover of the forms and the size of the production area required for this section depend on it.
With a weak pectin, improper cooking, insufficient acidity or incorrect recipe, the marmalade batch can be delayed in forms to 30 — 40 minutes. and more.
Cages duration mainly depends on the acidity of pH rather weight. The higher the concentration of hydrogen ions, the more passes the cage.
The stronger the marmalade mass is boiled down, the sooner the cage process develops (provided that during the boiling process
pectin was not particularly injured). At the same time, the acceleration of the charge is affected by the high degree of supersaturation of the solution (marmalade mass) with sugar.
The speed of the set depends on the quality of pectin. Normally gel-forming apple pectin gives a gradual growth at a temperature not higher than 70 °. Between the end of cooking and the beginning of the set, there is enough time for draining the mass, transferring it and pouring it into forms.
For the marmalade set-up process, it is important to ventilate the open surface of the marmalade in forms, which facilitates the free evaporation of water from the jelly and better cooling of the mass. The temperature of the ambient air also plays a role. The thermal conductivity of the mold material is also important.
According to VNII research, the following parameters of air passed into the forming conveyor zone are recommended: speed ~ 5 m / s, temperature 20 °, relative humidity 60 — 70%.
The role of alkali and buffer salts
In order to regulate the speed studneobrazovaniya pectin in the practice of the production of artificial (jelly), jelly, jelly candy shells and jelly on the basis of pectin is widely used abroad buffer salts. The most common of them: kremotartar (acidic potassium tartrate C4Н506K), diammonium phosphate (NH4) 2НР04, monosodium citrate NaC6Н7О7 et al. Addition of these salts is down cages pectin. The introduction of buffer salts in the pectin-sugar jelly mass makes it possible to broaden the terms of casting, m. To. The mass retains the liquid state and at the time cooling it.
In the USSR, on the proposal Hildebrandt et al. Regulated the use of the salts for the production of natural fruit and berry marmalade. In practice, it is currently used by the lactic acid sodium NaS3Н5О3And Na2NR04 with a dosage of up to 0,1 0,35% by weight of a mixture of prescription, the dosage of salt vary depending on the total (titratable) acidity of apple puree .
The choice of these alkaline sodium salts due to their availability. These salts allow free mechanical pumping of the marmalade mass without special precautions; there is no need to strictly limit the time of mass casting, which is especially important in the absence of pipe insulation for the mass and during manual casting.
Adding salts to the prescription apple-sugar mixture eliminates the need for constant mixing it to prevent the ion-bound gel from falling out before cooking the mixture. It plays a positive role in the direction of reducing the duration of the marmalade drying, as it allows for deeper boiling of the marmalade mass to a moisture content of 31 — 32% instead of 36 — 38%.
The main disadvantages of making salts in natural fruit and berry marmalade are as follows.
The addition of disodium phosphate, sodium lactate and other salts of alkaline nature in the amount from 0,1 to 0,35% to the weight of the prescription mixture shifts the pH of the latter to the alkaline side, while the pH value increases by 0,3 — 0,8. This leads to a decrease in the physiological sensation of natural acidity, which characterizes the natural taste of fruits and berries. As a result, it becomes necessary to add acid to the marmalade mass. However, it is difficult to restore the original acidity of the apple-sugar mixture, since in the alkalized or buffered medium, artificial acidification results in a too low pH shift.
The addition of sodium salts with alkaline in nature, causes peptization pectin and therefore adversely affect the consistency of marmalade. Experience has shown that in this case, in particular, impaired ability to sample its jelly form.
The introduction of alkaline sodium salts over 0,1% by weight of a mixture of prescription delays sucrose inversion during cooking marmalade jelly mass and drying to such an extent that causes most of the need for the introduction of invert syrup in marmalade.
Slowing the process cages marmalade caused by the addition of salts, reduces performance filling and molding equipment.
Vyborka Marmalade form
After the cages marmalade he is ready for a sample of forms and layout on sieve. A special mechanism makes sampling operation marmalade and lays it on the perforated aluminum sieve.
Employees of the Moscow confectionary factory "Udarnitsa" created a special unit that allows in the conditions of large-scale production to mechanize casting, loading, selection and sizing of marmalade on the sieve (Fig. 13).
The hot marmalade mass, ready for pouring, is fed by gravity or by means of a pump into the hopper of the filling head of the 1 machine.
Mounted on the conveyor piston entering the 8 2 excipients cell mass is extruded into rectangular shapes of stainless steel.
The filled 2 molding conveyor, passing through the 3 duct, cools, encountering a stream of conditioned air on its way.
Fig. 13. Driving unit for casting, cages, and the sample layout jam.
Skirting the end drum, forming conveyor passes through the lower box 4, where additional moisture evaporates from the surface of the jelly.
Under Warming plates 9 metal molds are heated from its back side; in this case between the marmalade and the surface of the cell forms a thin layer of syrup, weakening the adhesion between them.
Further, the molding conveyor 2 comes in contact with the conveyor belt 5, the web which is pressed against a rubber roller 10 to the forming conveyor, pressed into the cell forms and extracts the marmalade, as the latter adheres to the rubber layer of the web.
The cloth of the belt conveyor, bending around the end roller And at an acute angle, shifts the marmalade separating from it onto the 12 sieve, moving on the 6 chain conveyor.
Sieve with marmalade removed from the chain conveyor and transported on trucks to the dryer.
Washing 7 box is used to form a periodic washing with water jets directed upwards. Four-speed variator allows to regulate the number of cycles of the casting speed and interacting with each other transporters. Performance of the machine varies depending on the time of cages marmalade.
In the absence of sampling mechanism jelly form is selected from them at the end of cages by means of plugs (single, double, triple).
The same forks lay the marmalade on a sieve, patterned up, in even rows.
The described mechanism of sampling marmalade from the forms was not fully justified in practice. Therefore, other sampling methods are currently being developed.