RU2327368C1 - Blanched fast frozen vegetables and method of their production - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: method of preparation of blanched fast frozen vegetables, mainly potatoes, includes blanching of washed, peeled and cut fresh vegetables with steam at temperature of 90 - 96°C for 3-5 minutes, further cooling in cold running water down to temperature of 8 - 15°C, afterwards moisture is removed from vegetables surface with air flow at temperature from 0 to minus 5°C with further freezing at temperature of minus 25 - 35°C in suspended condition.

EFFECT: invention allows to preserve taste properties; food and biological value of products and to increase its shelf life practically without loss of value.

2 cl, 3 ex

Description

The invention relates to the field of processing agricultural products, namely to freezing potatoes and vegetables. The method can be used in areas with stable winter freezing temperatures.

Potatoes and vegetables play an important role in human nutrition. For the normal functioning of the human body, not only energy sources are necessary, but also vitamins, mineral salts, various acids, digestive aids, flavoring and aromatic substances. Potatoes and vegetables contain many of them. It is very important not only to grow, but also to choose a method of storing and processing potatoes and vegetables that will maximize the taste and nutritional value of the product for a long period of time, including the winter and spring season, when the lack of vitamins is felt especially sharply.

The well-known "Method for producing frozen pre-cooked potato chips and frozen pre-cooked potato chips" (Patent for invention RU No. 2055489, A23L 1/216, publ. 1996.03.10), including cleaning, cutting into thin slices, blanching in water, dehydration with hot air, keeping to achieve equilibrium humidity, preliminary frying and freezing, characterized in that at the same time as dehydration, blanching with moist hot air is carried out for 5-15 minutes at a temperature a dry bulb temperature 110-140 ° C.

The disadvantages of this method include the following.

Firstly, double blanching: blanching in water and blanching with moist hot air for 5-15 minutes, while carbohydrates and vitamins C and B are washed out of the product.

Secondly - preliminary frying before freezing. Vegetable fat or a mixture of fats is used to fry potatoes. Prolonged heating (180 ° C) leads to the oxidation of fats (interaction with atmospheric oxygen), a change in organoleptic properties, and a decrease in their nutritional and biological value. In addition, the primary oxidation products have carcinogenic properties and have a toxic effect on the human body.

The closest technical solution to the claimed one is "Frozen potato product and method for its production" (Application for invention RU No. 2003131336, A23B 7/04, publ. 2004.12.27, prototype), which includes stages

(a ') immersing the peeled, chopped and washed fresh potatoes in saline with a food additive as a preserving antioxidant agent with continuous stirring at a temperature T1 between 55 ° C and 75 ° C for a period of time t1 between 5 and 15 minutes, preferably 10 minutes at a salt concentration between 0.1% and 2% (w / v) and an additive concentration between 0.5 and 1.5% (w / v);

(b ') immersing the potatoes from step (a') in an aqueous solution with a homogenizing color, alkalizing and stabilizing the structure of the food additive for a time t2 between 20 and 40 minutes at a temperature T2 between 55 ° C and 70 ° C with an additive concentration between 0, 5 and 2% (w / v);

(b ") cooling the potatoes from step (b ') by immersion in an aqueous solution with a temperature of T3 between 5 ° C and 20 ° C for a time t3 between 2 and 10 minutes, possibly with the addition of food additives to improve color or taste;

(c ') drying the potatoes from step (b ") with an air stream at a temperature of T4 between 3 and 25 ° C for a time t4 between 2 and 10 minutes at an air speed of between 0.5 m / s and 4 m / s and relative humidity between 15% and 40%;

(d ') freezing potatoes from step (c') by any of the conventional plant product freezing systems known in the art.

The disadvantages of this method include double blanching of potatoes with an aqueous solution of 55-75 ° C in stage (a ') and 55-70 ° C in stage (b') for a long time (20-40 min) for washing out reducing sugars, while carbohydrates are also washed out of the product (Amylose - as an integral part of starch).

Saline solution with a food additive as a preserving antioxidant agent, in which the potatoes are immersed in stage (a '), destroys vitamins B and C.

To improve the taste and color in stages (b ') and (b "), a food additive is introduced into the aqueous solution, while the external property of the potato is improved, but the nutritional and biological value of the product is significantly impaired.

The problem to which the claimed technical solution is directed is to select methods of processing, storage and transportation of potatoes and vegetables that will maximize the preservation of the taste and nutritional value of the product over a long period of time, reduce the cooking time of the finished dish.

The technical result is to prevent the washing out of hot substances of beneficial substances and vitamins by accelerating the thermal effect on the product, rapid uniform freezing of potatoes and vegetables.

To achieve a technical result in a known method for producing blanched, quick-frozen potatoes and vegetables, including blanching washed, peeled and chopped fresh potatoes and vegetables, cooling and drying potatoes and vegetables before freezing and freezing, according to the invention, blanching of potatoes and vegetables is carried out with steam for 3-5 minutes, the potatoes are cooled in running water to a temperature of 8-25 ° C, and the fast freezing of potatoes and vegetables is carried out in suspension (in fluidization s continuous freezers). In this case, the blanching of potatoes and vegetables is carried out with a steam of 90-96 ° C.

In addition, before freezing, drying is carried out, moisture from the surface of the potato is removed by an air stream, the temperature of which is 0 minus 5 ° С.

In addition, potatoes are frozen at a temperature of minus 25-35 ° C.

In contrast to the prototype, where potatoes are immersed twice in solutions at a temperature of 55-75 ° C for 5-15 and 20-40 minutes, in the inventive method, in order to inactivate the enzymatic processes leading to darkening of the product, they use a single short-term high-temperature effect on product, namely steam exposure for 3-5 minutes, while the physical and technical properties of potatoes and vegetables are improved, carbohydrates and vitamins C and B are not washed out. This effect is achieved by reducing the time of heat treatment of products. A blanching time of less than 3 minutes will not produce the desired result, and with a blanching time of more than 5 minutes, the texture of potatoes and vegetables changes.

In the process of technological processing of potatoes and vegetables, unlike the prototype, cooling is carried out in cold running water to a temperature of 8-25 ° C and food additives and chemicals are not used, which eliminates the possibility of a harmful effect of the product on human health, including on the children's body.

In contrast to the prototype, drying of potatoes and vegetables is carried out by a stream of air at a temperature of 0 minus 5 ° C, and not by hot air, which destroys amylose.

Unlike the prototype, where freezing is carried out using any of the conventional systems for freezing plant products, quick freezing of potatoes and vegetables is carried out in suspension, which ensures uniform freezing of the product without destroying the texture.

Consider examples of the implementation of the method for specific examples.

Example 1: POTATOES. A method of obtaining blanched quick-frozen potatoes includes the following processing steps.

1. Sort

Potatoes are sorted manually or on conveyors of the type A9-KKT-1, A9-KKT-2, the tubers are wrinkled, sluggish, having mechanical damage and damaged by agricultural pests.

2. Calibration

Potato calibration is performed manually or on calibration machines such as A9KX.

3. Washing

The raw materials received in production are washed thoroughly until complete removal of contaminants. Raw materials are washed manually or in washing machines at a water pressure of 200-300 kPa (2-3 kgf / cm ² ).

The water used for washing and rinsing must meet the requirements of GOST R51232, San Pin 2.1.4.1074-01, the quality of the washing is systematically monitored.

4. Cleaning

Cleaning is done manually or mechanically on machines of the type MSK-350.

For peeling potatoes, in addition to mechanical, a steam-thermal method can be used at a steam pressure of 0.8 MPa in apparatuses of the type A9-CNI.

5. Slicing

Potatoes are cut on machines of the MP-500, A9-KR2 V, RSKE-KIM type with rings or circles from 2 to 15 mm thick, cubes with a long face from 3 to 19 mm or straws with a cross section from 3 to 19 mm or chopped into strips up to 7 mm wide.

6. Inspection

Potatoes are inspected on an inspection conveyor.

7. Blanching

Potato blanching is carried out in hot or boiling water, or with hot steam for 3-5 minutes.

Use blanchers type A9-KBZH.

8. Cooling

After blanching, the potatoes are cooled in running water to a temperature of 10-20 ° C.

9. Moisture removal

The moisture removal from the surface of the potato before freezing is carried out with air at an air velocity of about 1.0 m / s at a temperature of -5 ° C.

10. Inspection

The potatoes are inspected on an inspection conveyor with a magnetic device and sent for freezing.

11. Freezing

Potatoes are frozen in continuous or intermittent air freezers such as ASMF-20, Ya10-AZA, ASM-100YA, ASM-2100 or foreign analogues at an air temperature of minus 30-35 ° C or in a chamber freezer at a temperature of no higher than minus 24 ° C with forced air circulation. In continuous freezers, potatoes are frozen in bulk. The duration of the freezing of potatoes in the fluidization quick freezers of continuous operation in the fluidized bed (air velocity 3-6 m / s) no more than 15 minutes.

Example 2: CARROT. A method of obtaining blanched quick-frozen carrots includes the following processing steps.

Stage 1-6 see example 1

7. Blanching

Blanching of root crops of carrots is carried out in hot or boiling water, or with hot steam for 3-4 minutes at a temperature of 92-94 ° C.

Use blanchers type A9-KBZH.

8. Cooling

After blanching, the roots of carrots are cooled in running water to a temperature of 10-13 ° C.

9. Moisture removal

Removing moisture from the surface of root crops before freezing is carried out with air at a speed of about 1.0 m / s at a temperature of 3-4 ° C.

10. Inspection

Root crops of carrots are inspected on an inspection conveyor with a magnetic device and sent for freezing.

11. Freezing

Root crops of carrots are frozen in continuous or periodic aerial freezers such as ASMF-20, Y10-АЗА, АСМ-100Я, АСМ-2100 or foreign analogues at an air temperature of minus 28-34 ° С or in a chamber freezer at a temperature not exceeding minus 26 ° C with forced air circulation. In continuous freezers of continuous action, root crops are frozen in bulk. The duration of freezing of root crops in fluidization quick-freezing apparatuses of continuous action in the fluidized bed (air velocity 3-6 m / s) no more than 15 minutes.

Example 3: BEET. A method of obtaining blanched quick-frozen beets includes the following processing steps.

Stage 1-6 see example 1

7. Blanching

Blanching beets is carried out in hot or boiling water, or with hot steam for 4-5 minutes.

Use blanchers type A9-KBZH.

8.Cooling

After blanching, the beets are cooled in running water to a temperature of 12-15 ° C.

9. Moisture removal

The moisture removal from the surface of root crops before freezing is carried out with air at a speed of about 1.0 m / s at a temperature of 4-5 ° C.

10. Inspection

Beets are inspected on an inspection conveyor with a magnetic device and sent for freezing.

11. Freezing

Beet root crops are frozen in continuous or intermittent air freezers of the ASMF-20, Y10-АЗА, АСМ-100Я, АСМ-2100 type or foreign analogs at an air temperature of minus 30-35 ° C or in a chamber freezer at a temperature not exceeding minus 26 ° C with forced air circulation. In continuous freezers of continuous action, root crops are frozen in bulk. The duration of freezing of root crops in fluidization quick-freezing apparatuses of continuous action in the fluidized bed (air velocity 3-6 m / s) no more than 15 minutes.

This way you can get blanched, quick-frozen white cabbage, cauliflower, broccoli cabbage, Brussels sprouts, kohlrabi cabbage, table turnip, sweet corn, zucchini, squash, eggplant, food pumpkin, sweet pepper, tomatoes, green peas, green beans, onions, onions garlic, root parsley, root celery, dill parsley, celery, leek.

The closest analogue to the claimed blanched quick-frozen potato obtained by the above method is a frozen potato product (Application for invention RU No. 2003131336, A23B 7/04, publ. 2004.12.27, prototype), which can be stored for long periods of more than 12 months without blackening, has a uniform and dense texture, retaining its organoleptic properties after frying for 15-20 minutes, with a composition measured by the yield of dry matter, similar to the composition of fresh natural potatoes, in the interval It is between 18 and 24%.

The disadvantages of this frozen potato product include the fact that vitamins are not stored in it during the production method described in the prototype.

The problem to which the claimed technical solution is directed is to select methods of processing, storage and transportation of potatoes that will maximize the preservation of the taste and nutritional value of the product over a long period of time, reduce the time of preparation of the finished dish.

The technical result is to prevent the washing out of hot water of useful substances and vitamins, by accelerating the thermal effect on the product, rapid uniform freezing of potatoes.

Frozen blanched potatoes, including proteins, fats, carbohydrates and vitamins C and B in the following ratio of ingredients, wt.%:

proteins - 2.5-2.7;

fats - 0.2-0.25;

carbohydrates - 20.0-20.5;

vitamins C and B - 20.2-20.6 mg / 100 g;

the rest is minerals and water.

Quick-frozen blanched potatoes can be stored for a long period, 12 months at a temperature of minus 18 ° С, and is also a universal product for preparing first and second courses: soup, mashed potatoes, fried, baked and stewed potatoes, etc., in addition, the cooking time is 3-5 minutes, while the taste, nutritional and biological value are preserved: the taste, appearance, color, naturalness, freshness and texture are preserved, according to the content of basic nutrients (carbohydrates, fats, vitamins c) it practically corresponds to fresh (not frozen) potatoes of a new crop, has a higher protein content than in fresh potatoes.

Comparison results of finished products obtained from frozen potatoes and raw potatoes from the 2005 harvest: in a sample of finished products obtained from quick-frozen potatoes, the loss rate of ascorbic acid was 28.2% (from 20.59 to 14.78 mg / 100 g) the loss of thiamine was 30.8% (from 0.052 to 0.036 mg / 100 g); in the finished sample from fresh products, the loss of these vitamins was higher: for ascorbic acid 39.5% (from 20.06 to 12.14 mg / 100 g), for thiamine 44.3% (from 0.079 to 0.044 mg / 100 g) .

Packed potatoes are stored in refrigerators at a temperature not exceeding minus 18 ° С and relative humidity up to 95% for no more than 12 months from the date of manufacture.

It is allowed to store potatoes at a temperature of minus 15 ° C for no more than 8 months, and at a temperature of minus 12 ° C for no more than 6 months from the date of manufacture.

There is a sanitary and epidemiological opinion on the use of blanched quick-frozen potatoes within three days after the end of the defrosting process at a temperature of + 2 ° C to + 6 ° C.

Potatoes are used in public catering establishments, educational and public health institutions, in organizing meals for school and preschool children, as well as in military nutrition: military clinical hospitals, military units of the Air Force, Navy, flight and medical rations.

The technology of preliminary preparation and quick freezing allows you to make the product versatile in use, waste-free, convenient for transportation, storage and preparation, preserve taste, nutritional and biological value.

An analysis of the products by the Ural Center for Health Nutrition of the Federal State Institution of Medical Science and Education of the Russian Federation for Health Protection and Consumer Protection of Rospotrebnadzor showed that after a year of storage of blanched quick-frozen potatoes, taste, appearance, coloring, naturalness, freshness and texture are preserved. According to the content of basic nutrients (carbohydrates, fats, vitamins), potatoes practically correspond to fresh (unfrozen) products of the new crop. As a result, potatoes have no restrictions on cooking methods. It, like fresh, can be used for making soups, mashed potatoes, as well as for frying, stewing, baking.

Thus, given the long shelf life of 12 months at a temperature of minus 18 ° C, we can conclude that the nutritional and biological value of blanched quick-frozen potatoes is preserved.

The claimed technical solution "Method for producing potatoes and vegetables blanched quick-frozen and potatoes blanched quick-frozen" allows you to save all the qualitative characteristics of the product and bring its culinary properties to a high degree of readiness. In addition, it should be noted the technological aspects of the cooking of potatoes and vegetables that have a beneficial effect on the hygienic safety and nutritional value of the products - the absence of a primary cooking step (washing, cleaning, cutting), a significant reduction in cooking time.

In addition, studies were conducted and a sanitary and epidemiological conclusion was obtained on the use of blanched quick-frozen potatoes and vegetables for three days after the end of the defrosting process at a temperature of + 2 ° C to + 6 ° C, which allows us to solve a number of problems associated with transportation, storage and use blanched quick-frozen potatoes and vegetables.

Due to the wide range of dishes and the many methods of cooking blanched quick-frozen potatoes and vegetables, increasing the shelf life of products with almost no loss of nutritional and biological value, it is possible to create a diet balanced in basic nutrients and energy in organized children's groups, in catering establishments of educational institutions and health care facilities.

The Military Scientific Committee of the Central Control Center of the Ministry of Defense of the Russian Federation highly appreciated the technological and organoleptic properties of blanched and quick-frozen potatoes and vegetables, and tested them according to the flight and medical standards in the military medical institutions MVO, LenVO, PUrVO, SKVO, and the Northern Fleet.

Claims (2)

1. A method of obtaining blanched, quick-frozen vegetables, mainly potatoes, characterized in that it provides for blanching washed, peeled and chopped fresh vegetables with steam at a temperature of 90-96 ° C for 3-5 minutes, followed by cooling in cold running water to a temperature of 8- 15 ° C, after which moisture is removed from the surface of vegetables by air flow at a temperature of 0 to minus 5 ° C, followed by freezing at a temperature of minus 25-35 ° C in suspension. 2. Vegetables blanched quickly frozen, mainly potatoes, characterized in that they are obtained by the method according to claim 1.