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Canned fruit and berry puree

Canned fruit and berry puree
Fruit puree and pulp products are primarily carbohydrate composition favorable for the development of yeasts, molds and certain acid-forming bacteria. When scalding fruits whole microflora on the surface died, but in the future,
After scalding, the processing of puree and storage of possible re-infection of said microorganism. Getting into the mashed potatoes, yeast causes alcoholic fermentation in it. Therefore, to protect against damage puree intended for long-term storage, canned.
There are several methods of preserving: chemical method, heat sterilization and freezing. The method of chemical canning is most common in practice. It consists in the fact that chemical substances (preservatives) are introduced into the preserved product, acting bactericidally on the microorganisms of the given medium when they are dosed in small amounts. The main requirements for preservatives of fruit and berry puree are as follows: harmless to the human body in the applied doses, chemical stability, i.e. The invariance of the chemical composition throughout the entire period of its action, non-volatility and chemical indifference to the puree itself. It is necessary that the preservative has no effect on taste, color, gel-forming ability of the puree and has good solubility in water.
Of the long list of preservatives authorized for use in the food industry, the most commonly used for the preservation of fruit and berry puree and pulp benzoic acid and sulfuric acid.
     Benzoic acid (C N5SOON) has a strong bactericidal effect in acidic media with a low content of nitrogenous substances, which is typical for fruit and berry puree. The required dosage for preserving puree benzoic acid vary within 0,05-0,10% depending on the natural acidity of the mash.
Benzoic acid and low-volatile compounds, which makes it possible to use them for preserving puree both hot and cold in hermetically apparatus. However, benzoic acid, slightly soluble in water, so it is used most often the sodium salt.
Prepare 10% or benzoynonatrievoy 20% hot salt solution (70-80 ° C) water and after filtration was added with stirring to the hot purée. The amount of preservative taken based solution to provide a concentration of benzoic acid in mash within 0,07- 0,10%.
     Sulfurous acid (H2S03) is more potent preservative than benzoic acid. It has a bactericidal effect against yeasts and molds.
However, sulfurous acid preservative and has a number of disadvantages. It is harmful to the human body is greater than the benzoic acid, as it is a cumulative poison that its consumption as accumulated in the body. In this connection, sanitary legislation strictly limits the permissible residual content of the preservative in the finished product (not more than 100 mg total S02 on 1 kg jellies and pastes, that is to 0,01% to the weight of the finished product).
Sulfurous acid is volatile, long-term storage mash is partially oxidized into sulfuric acid, is reacted with sugars and other organic substances puree, forming resistant sulfur compounds. Thus, with a partial time unpickle puree. Due to the volatility of sulfurous acid during preservation and processing puree considerably deteriorated working environment.
Sulfurous acid is a preservative, 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 and pulp in the absence of other preservatives. In the presence of benzoic acid and its salts necessary to use them advantageously.
For the preservation of fruit and berry puree and pulp sulfurous acid is used in the form of 6-7% solution or 100% solution of bottled gas SO2 Calculating the amount of preservative is conducted on the basis of the number of Shore, the working concentration of sulfurous acid and dosage 0,10-0,12% gas S02 on puree weight.
    The solubility of sulfur dioxide sharply decreases with increasing temperature. Therefore, before the mash is cooled to canning 50- 55 ° C, and for desulfitatsii contrary, heated to 100 ° C.
In recent years, for the preservation of fruit pieces used sorbic acid (SN3 = CH-CH = CH-COOH) and its sodium salt. They have quite a strong bactericidal effect, and in small doses are considered harmless to the human body. 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%.
  In addition to chemical methods of canning puree, used and others: heat sterilization, drying, jelly sugar, freezing. These methods have not yet found a fairly wide application in the production of apple puree.
Canned puree, pulp, intended for long-term storage, is poured into the barrels with a capacity of up to 100 200 l.
Sterilizovannoe puree.
For the production of dietetic and children's products are used fruit and berry puree: apple, apricot, plum, cherry, black currant and cranberry.
After washing fruits and berries rubbed on special machines.
Pureed pulp is poured into a glass or cans, hermetically sealed and sterilized by heat.
Dense and dry applesauce. These kinds of mashed potatoes are obtained from a conventional apple sauce by boiling until 15-17% or drying to 90-95% solids. The use of compressed puree reduces production cycle pastel products.
Dense puree usually made from pulp, and not from the puree. Puree has low thermal conductivity, high viscosity and often sticks to the surface of the heat exchanger when boiling. The resulting compacted pulp puree lighter and has better gelling properties.
  In order to reduce the hydrolytic cleavage of pectin boiling is conducted at low temperatures in a vacuum apparatus.
When boiling occurs desulfitatsiya product, so the sealed puree usually added preservative.
Of considerable interest in terms of savings on packaging and transportation costs, reduce storage space and improve the marmalade-Pastila product technology is a dry fruit and berry puree.
  By removing by drying the bulk of the water, dry mashed acquires sufficient resistance to microbial spoilage without preserving its chemicals. But dry mash has a hygroscopic property due to high content of invert sugar, so it must be zatarivatsya in plastic bags.
   Powdered mashed readily soluble in cold water and liquid fruit puree, which allows its use for normalization of solids in a liquid sauce, as well as for compressed puree without boiling.
Production of dry mashed reduced to the normal dried liquid puree. Important factors that affect the physical and chemical properties of dry mashed potatoes, are the temperature and duration of drying. Dried at a minimum temperature within 3-4 with applesauce practically does not change its properties. These drying parameters of the best-respected when using spray and vacuum Roller dryers.

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