The quick-frozen berries and mushrooms represent the whole components packed and frozen on technology of a shock freezing at a temperature — 35–40 °C before achievement in a product of temperature of -18 °C and intended for storage and realization at this temperature.
Suitability of wild-growing berries and mushrooms for further freezing is defined first of all by their specific (genetic) features. It:
- harmonious taste, pronounced aroma, beautiful appearance and coloring in a consumer maturity;
- high content of solids, including sugars;
- security with biologically active agents — vitamin C, carotene, antotsiana, catechins that predetermines not only the vitamin value, but also richness of taste and appearance.
- the minimum change of moisture-holding ability after freezing;
- structural durability of fabrics, their resistance to cracking, that is the increased content of the substances providing a consistence of pulp and integrity of integumentary fabrics — celluloses, gemitsellyuloz, protopectin.
Freezing is based on use of temperatures below krioskopichesky that stops or slows down many biochemical and microbiological processes. Low temperatures cause effective decrease in quantitative and high-quality losses. Quality of production depends on a look and a condition of raw materials, its preparation and a way of freezing. For processing berries in which the residual amount of pesticides, toxic elements exceeds the most admissible levels approved by the Ministry of Health are not allowed.
The quick-frozen production of high quality turns out at fast and superfast freezing. On organoleptic indicators (appearance, taste, aroma) the quick-frozen berries and mushrooms differ from fresh berries and mushrooms a little. In them biologically active agents well remain, besides, freezing allows to use the most economic types of packing materials. Fast and superfast freezing provides the high speed of process, at the same time water crystallizes in the form of the smallest crystals at the same time both in cages, and in intercellular spaces.