RU2075949C1 - Method to treat unpeeled potatoes - Google Patents

Abstract

FIELD: food industry. SUBSTANCE: method deals with thermal treatment in ultra-high frequency field for 1.5-10 minutes at frequency to provide temperature of 100 C in tuber center. Cooling is conducted in two stages: the first stage cooling deals with temperature of 50±10^oC in tuber center, the second stage - up to 20±10^oC in tuber center, freezing is conducted up to 18±2^oC in tuber center. EFFECT: higher efficiency to be applied in the sphere of public nutrition.

Description

 The invention relates to the food industry and can be used in enterprises of the processing industry, catering, as well as in the production of quick-frozen vegetables and fruits and, in particular, unpeeled potatoes.

A known method for the production of frozen potatoes, including sorting, peeling, washing whole potatoes, blanching at a water temperature of 100 ^o C for 5 min, cooling and freezing.

 The disadvantage of this method is the inability to obtain a high-quality semi-finished product suitable for long-term storage. This is caused, firstly, by peeling potato tubers from the peel and, secondly, by heat treatment with hot water. In addition, during the specified heat treatment, leaching of nutrients occurs, which leads to a negative phenomenon on the surface of the potato.

 A known method of processing potatoes, including pre-processing, including washing unpeeled potatoes, calibrating tubers, sorting them for quality, peeling, washing peeled potatoes, slicing, washing starch with cold water, separating water from potatoes, and heat treatment including blanching and roasting, as well as refrigeration processing, including cooling and freezing.

 The disadvantages of this method are the same as in the known production method. In addition, during storage of frozen tubers that are not protected by skin, significant shrinkage of potatoes occurs, and when it is defrosted, tubers are darkened.

 Closest to the proposed method is the preparation of unpeeled potatoes, which includes washing, calibration, sorting, heat treatment and freezing.

 The storage time of diffused potatoes before cooking is several hours. This is due to significant bactericidal contamination and drying of the surface of the tubers of peeled potatoes at a positive temperature, which also significantly reduces the quality of the product.

 The aim of the invention is the intensification of the processing of potatoes, preserving the quality of the potato semi-finished product during storage, as well as increasing the shelf life.

The goal is achieved in the proposed method due to the fact that after pre-processing of unpeeled potatoes, heat treatment is carried out in the microwave field for 1.5-10 minutes, moreover, different frequencies are used for tubers of different sizes, which provide semi-finished potatoes, and refrigeration is carried out in three stages: pre-cooling to a temperature in the center of the tuber 50 ± 10 ^o C, final cooling to a temperature in the center of the tuber 20 ± 10 ^o C and freezing potato cooled to evap s in the center of the tuber -18 ± 2 ^o C.

 A search by sources of patent and scientific and technical literature did not allow to identify an identical technical solution, which allows us to conclude that the proposed method meets the criterion of "novelty."

 Comparison of the proposed method not only with the prototype, but also with other similar methods, did not allow to reveal in the latter a combination of features that distinguish the claimed method from the prototype, which allows us to conclude that the proposed method meets the criterion of "inventive step".

Example:
Carefully washed potato tubers in a peel with a diameter of 40 mm were placed in a microwave field with a frequency of 2450 MHz for 4.5 minutes. After heat treatment, the temperature in the center of the tuber was 100 ^o C.

Then the tubers were subjected to preliminary cooling for 20 minutes on the grid by blowing air with a temperature of 20 ^o C, to a temperature in the center of the tubers of 50 ^o C. Then the cooled tubers were subjected to final cooling to a temperature of 20 ^o C.

 After cooling, the peel of the tubers was separated from the potato and wrinkled due to moisture loss of the potato when processed in a microwave field. The mass of tubers decreased by 20% in relation to the initial mass.

Chilled tubers were frozen for 45 minutes in a freezer with an air temperature of minus 30 ^o C, while the temperature in the center of the tuber dropped to minus 18 ^o C.

 After freezing, the potato tubers did not have a violation of the integrity of the peel.

Frozen tubers were stored at a temperature of -18 ± 2 ^o C for 30 days.

Then, the frozen tubers removed from storage were defrosted for 12 hours at room temperature (18 ^° C).

 Defrosted potato tubers were peeled and tasted.

To obtain comparative data in parallel, heat treatment (cooking) of potatoes in water with a temperature of 100 ^o C.

 The taste of potatoes processed by the proposed method was identical to the taste of potatoes in a peel boiled in boiling water.

 As a result, it was found that the proposed method of processing potatoes allows to obtain a semi-finished product suitable for long-term storage with high quality product.

 The specified semi-finished product after defrosting and storage at room temperature retained its qualities for 4-7 days.

Claims (1)

A method of processing potatoes in a peel, including washing, calibrating tubers, sorting, heat treatment, cooling and freezing, characterized in that the heat treatment is carried out in a microwave field for 1.5-10 minutes at a frequency providing a temperature in the center of the tuber of 100 ^o C, cooling is carried out in two stages, in the first stage it is cooled to a temperature in the center of the tuber 50 ± 10 ^o C, in the second stage to 20 ± 10 ^o C, and freezing is carried out to a temperature in the center of the tuber - 18 ± 2 ^o C.