RU2317711C1 - Method for producing of dried granulated pumpkin - Google Patents

Abstract

FIELD: food-processing industry.

SUBSTANCE: method involves preliminarily cutting, pressing and granulating raw material, with juice being expelled at grinding and pressing stages; drying resulted granules by providing infrared power feeding from each side, with initial content of dry substances in pumpkin granules constituting 16%, diameter of granules making 0.004 m, and heat flux density making 2.69 kW/m².

EFFECT: increased yield of dry product, increased nutrient value and content of vitamins.

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Description

This invention relates to the food industry, namely, the production of dry vegetable concentrates, mainly used in the canning industry for the production of biologically valuable semi-finished products, canned food, and also as additives in food, feed, medical and veterinary products, recommended for all population groups, in including for diet food.

A known method of drying high humidity materials [see RF patent No. 96116944, year 1998], which includes drying the material under the influence of infrared radiation in the first stage and drying in the second stage, moreover, at the first stage, one side of the material is exposed to the maximum intensity, and the other side to the minimum, and the side exposure changes in the second stage .

This method does not provide for the removal of free and loosely bound moisture by more economical hydromechanical methods (grinding, pressing, etc.), the creation of volumetric energy supply, which leads to multi-stage drying. In addition, this method does not provide a highly developed heat and mass transfer surface, which leads to a decrease in productivity and quality of the finished product.

Closest to the proposed method is a method of producing a dry granular product based on potatoes, which is mixed with pumpkin powder, including cleaning the raw materials, grinding, cooking, mixing with other components and granulating while moistening and subsequent drying of the granules in a vortex layer [see RF patent No. 97117731, year 1999] - prototype.

This method of drying does not allow to obtain dry products from pumpkin of high quality and a relatively large yield of the finished product due to uneven drying of particles, due to surface energy supply, low efficiency of internal moisture transfer, local under-drying of large and burning of small particles, high friability and violation of the shape of granules, small the degree of moisture extraction during grinding and the need for additional wetting of the mixture, as well as due to the significant amount of auxiliary overall equipment ments to dedusting, aspiration and losses during separation of the finished product, the propensity to aggregate (sticking) material, the difficulty of providing the set of output parameters for the vortex-dried.

The technical problem is the intensification of the operation of drying a granular product.

The technical result of the present invention is to increase the specific yield of dry product, the maximum preservation of its nutritional value and vitamins.

It is achieved by the fact that the method for producing a dry granular product involves pre-grinding, pressing and granulating the raw materials, as a result of which part of the moisture (juice) is separated off at the grinding and pressing stage, which are less energy-intensive operations compared to drying, and sent for further processing. The obtained granules are dried with a comprehensive infrared energy supply with an initial solids content in pumpkin granules of 15 to 18%. The method is carried out using light infrared (IR) emitters of the type KGT-220-I000 at a voltage of 130 V to 160 V (wavelength corresponding to a maximum radiation of 1.30 to 1.56 μm), the diameter of the granules is from 0.002 m to 0.008 m ; with a heat flux density of 2.5 kW / m ² to 3 kW / m ² . In this case, the removal of the dry product can reach P = 26 kg / (m ² h).

A specific implementation of the proposed method can be illustrated by examples of its implementation.

Example 1

The pumpkin of the Ordinary variety was washed, peeled, and the seed nest was removed. Then subjected to granulation with prepress (to a moisture content of 84%). The obtained granules had:

equivalent diameter d = 0.004 m

length l = 0.01 m.

Drying was carried out at a heat flux E = 2.69 kW / m ² , λ = 1.34 μm.

The performance was P = 14.6 kg / m ² .

Example 2

The pumpkin of the Ordinary variety was washed, peeled, and the seed nest was removed. Then subjected to granulation with prepress (to a moisture content of 84%). The obtained granules had:

equivalent diameter d = 0.007 m

length l = 0.015 m.

Drying was carried out at a heat flux E = 4.01 kW / m ² , λ = 1.16 μm.

The performance was P = 18.7 kg / m ² .

Example 3

The pumpkin of the Ordinary variety was washed, peeled, and the seed nest was removed. Then subjected to granulation with prepress (to a moisture content of 84%). The obtained granules had:

equivalent diameter d = 0.004 m

length l = 0.01 m.

Drying was carried out at a heat flux E = 2.69 kW / m ² , λ = 1.45 μm.

The performance was P = 26 kg / m ² .

The effectiveness of the method is illustrated by comparative tables 1, 2, which give comparative indicators of the chemical composition of dry pumpkin-based products.

The heat treatment of plant products containing a noticeable amount of pectins is aimed at destroying the secondary structure of pectin and partial release of water. This process starts at temperatures above 60 ° C and then accelerates about 2 times for every 10 ° C of temperature increase. As a result, the mechanical strength decreases by more than 10 times.

The mechanical strength of plant products depends on their water content. The less free water in a product, the greater its strength under other equal conditions. Table 1 shows the chemical composition of the powders and some pumpkin-based products dried by convective drying.

Table 1 Chemical composition of powders and some pumpkin-based products,% Product name Water Sugar Pectin Organic acid Ash Nitrogen Substances Cellulose β-carotene, mg /% Pumpkin powder 6-8 40-57 5-7 0.9-1.2 8-10 9-14 10-12 19-50 Pumpkin porridge 6-8 38-39 1.6-1.8 0.2-0.4 1,5-2 21-23 3.7-4 5.7-15

An experimental verification of the combination of the process of granulation and drying of pumpkins was carried out. Table 2 shows the chemical composition of the finished product.

table 2 The chemical composition of granular dry pumpkin,%. Water Sugar Pectin Organic acid Ash Nitrogen Substances Cellulose β-carotene, mg /% 7-10 45-60 7-9 0.9-1.3 9-11 7-12 9-14 20-55

Positive effect - this method allows several times to reduce the drying time and provides almost complete preservation of vitamins and active substances. Processed products are reduced in mass by 8-10 times, and in volume by 3-4 times, acquires the ability to long-term storage in ordinary (room) conditions and relatively quick recovery in water, a comparative analysis with the feedstock and dry powders obtained by other methods dehydration shows that the content of β-carotene, fiber, ash, pectin, sugar exceeds the content of analogues and this confirms the validity of the choice of dehydration method.

Claims (1)

A method of obtaining dry granulated pumpkin, including preliminary grinding, pressing and granulating the raw materials, while at the stages of grinding and pressing, part of the juice is separated, and after granulation, the product is dried with a comprehensive infrared energy supply with an initial dry matter content of 16% in pumpkin granules, the diameter of the granules is from 0.004 m, and the heat flux density is 2.69 kW / m ² .