SU1220614A1 - Method of processing fruit and berry raw material - Google Patents

Description

The invention relates to food processing, in particular, to methods of drying without the use of heat by freezing and evaporation in a vacuum, and can be used in the preparation of powders from fruit, year, vegetables, spice, herbal tea, hops, meat, fish and other products of plant and animal origin.

The purpose of the invention is to increase the biological and nutritional value of the finished product.

The method is carried out in a special manner.

Chopped fruits (sliced into slices, ie, about 5 mm thick, blocks, pears, oranges and lemons with or without dried zest), years, squeezing from a block, etc. subjected to rapid freezing by immersion in a container with liquid nitrogen for 2-3 minutes. The frozen starting products are placed in a freeze-drying chamber and they are vacuum freeze-dried using liquid nitrogen as a refrigerant. Sublimation drying is carried out until the source product has a moisture content of 0.1-0.01% (the control is most effectively carried out using the barometric method), starting at a pressure of 10 -8-10 P and temperature minus (25-30) C and ending at 10 Pa and temperatures plus (20-30) s. In this case, the leakage into the sublimation chamber without loading the source product should be no more than 30-10 lm / s. The duration of the freeze-drying day to ensure the specified moisture content of the dried product, depending on its type and degree of preliminary grinding, lies within 2-6 hours. So, for example, blocks, pears, lemons and oranges with dried peel cut into slices 5 mm thick require drying for 5 h, strawberries and black currants - 6 hours, squeezing out of the block - 2 hours. After the end of freeze-drying, the pressure in the chamber is increased to atmospheric by injecting gaseous nitrogen, the chamber is removed, the dried source product is removed, immersed return it to liquid nitrogen for 2–3 min to make it brittle and to prevent lumpiness and ground it in a nitrogen atmosphere, for example, in a demembrator.

20614J.

If you need to get powder

with a dispersion of 10–50 µm, the grinding in the desmembrator is carried out at least twice. If it is required to receive. powder with a dispersion of 1–10 µm, then, after grinding, the dismembrator is ground in a nitrogen environment, for example, in a ball cryo-mill, the body and balls must be made from porcelain and, moreover, the mill body must exclude moisture and oxygen from crushed product. After grinding, the obtained powder is dried in a vacuum chamber until it is 0.1-0.01% moisture, dried at a pressure of 10-4 Pa and temperature plus (20-30) C for approximately 20 -30 min. After drying, the pressure j in the vacuum chamber is expanded to atmospheric by injecting gaseous nitrogen and the resulting powder is packaged in an inert atmosphere (in gaseous nitrogen) into an opaque 2J gas-tight package (glass container, multilayer foil-based bags made of aluminum foil with thermoplastic coating, metal tins, etc.).

DP compare the quality of the powder obtained in different ways, use fresh fruit and the same years. first grade and one party collection.

For comparison, the processing of the initial product into powder was carried out in three ways: by heat drying and grinding in a screw mill (prototype method); freeze-drying and cryopolymer of the product frozen in liquid nitrogen, followed by drying the resulting powder in a nitrogen medium (proposed, method), freeze-drying and grinding in a screw mill (known method).

in the initial product and powders obtained by different methods, they control the activity of vitamins (C, B, B, carotene, E), as well as the content of Sugars, organic acids, protein and trace elements (Na, K, Ca, Mg, P).

In tab. Figure 1 shows the effect of various types of technology for obtaining powder from a block and pears on the preservation of vitamins and microelements in them, in Table. 2 - the effect of various types of technologies for producing fruit powders on the preservation of

thirty

35

40

45

SO

S5

these are sugars and organic acids, in table. 3 - chemical composition of fruit-bearing powders obtained by the proposed method.

As can be seen from the results of the experiments, the proposed method provides powders with higher compared with other methods, including the prototype, vitamin content equal to 93.4-99.2% relative to the original products, while this the indicator for the prototype method is 50-48%, and for the known method it is 80-84.3% (Table 1).

According to the proposed method, significantly more sugars and organic acids are saved in powders by 10 and 25-40%, respectively, compared to the prototype (Table 2).

The content of vitamins, sugars, organic acids, minerals, proteins obtained in the proposed method of fruit-bearing powders from various fruits and the year are presented in Table. 3

Separate operations are carried out at specific boundary conditions of pressure and temperature, which is; rye determined experimentally and are optimal.

The boundary values of these modes are justified as follows.

The time spent on drying depends on the initial temperature of the product and the pressure in the chamber at which the drying process takes place. The maximum drying speed (as shown by experiments) corresponds. pressure of 9 Pa, however, at the same time the drying temperature is higher,

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This results in a freezing effect that determines to a certain extent the quality of the final product. Therefore, the optimal end pressure

The drying process is a pressure of 810 Pa. At pressures greater than lOTI, the drying rate decreases dramatically, which increases the drying time. The end of drying at a temperature of plus

) 0 (20-30) s and the specified pressure ensures the moisture content of the product is not higher than 0.1-0.01% at which the product practically does not coagulate, and makes it possible to obtain high-quality powder with honest and long-term storage. The moisture content of the product depends on the flow into the chamber prior to loading and it should not exceed 3 10 L / m, otherwise the moisture content in the product will be 0.1-0.01%, which does not allow to get rid of the clumping of the powder. Drying at temperatures above + 30 ° C does not ensure the preservation of aromatic and nutrients

25 in the resulting product.

Thus, in the fruit-bearing powders obtained by the proposed method, compared to the powders according to the prototype method, the vitamins, aromatic and nutrients in relation to the original product are almost completely preserved; they smell, taste and color characteristic of fresh fruit and years. . Fine dispersion ensures the manufacture of a wide range of high-quality food products from powders. In addition, the powders are subject to long-term storage in the powdered state (in a hermetic package) with no change in quality.

thirty

Prototype

68,8

Sublimation Drying with Regular Grinding 68.8

Also

Sublimation onion drying with ordinary apple (from

whole fruits) 21.47

Apple (from pomace) 21,58

Pear 36,32 Orange 382.5 Lemon

Blackcurrant

Strawberry 224.0

0.049 0.133 0.101 2.40 68.52 44.31 23.00

0.119 0.226 0.540 3.27 0.119 0.236 0.098 2.10

65.71, 62.813 2.76 58.45 45.48 12.32

 2

68,8

D3,1

24.4

5.70

43.1

24.9

7.75

Table3

65.71, 62.813 2.76 58.45 45.48 12.32

Apple (from

whole fruits) 7.75 1.12

Apple (from

, 7

On lemon: Islote.

Editor E. Kopcha

Compiled by Y. Martynov

Tehred L.Oleynik Proofreader A.T.

Order 1503/2 Circulation 543 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch ShSh Patent, Uzhgorod, st. Project, 4

770 48

160

thirty

25

Claims (1)

METHOD FOR PROCESSING FRUIT-BASED RAW MATERIALS, including crushing the product, freezing in liquid nitrogen, vacuum freeze-drying and packaging in a sealed package filled with inert gas, characterized in that, in order to increase the biological and nutritional value of the finished product, freeze-drying is carried out until reaching a product temperature of 20 -30 C and humidity 0,1-0,017 while continuously decreasing pressure between 10 ³ and -8 x 10 'Pa to 10 Pa, and after freeze drying popolnitelno frozen in liquid nitrogen were ground in cFe e nitrogen to a particle size of 1-50 microns and dried at a pressure of 10 -10 Pa and a temperature of 20-30 ~ 0. >