Researches on the freezing of blueberries and green bean pods using an experimental model of a fast freezing equipment

In order to conserve perishable food and extend the permissible storage and marketing period, one of the best methods that uses artificial frost is freezing. The action of low temperatures leads to a slowing down of the modifying processes, both nutritionally and organoleptically. The researches presented within the paper aims to determine some specific parameters for the freezing process using an experimental model of a fast freezing equipment with liquid nitrogen. Experimental researches use two species of horticultural products, namely blueberries and green bean pods. The results indicate that the values of total freezing time, average linear freezing rate and liquid nitrogen consumption for quick freezing of blueberries were higher than those recorded for green bean pods. Also, with the lowering of the set temperature inside the freezing chamber, the freezing time from 0°C to the temperature of -15°C decreases, resulting in lower freezing times, higher average linear freezing rates and liquid nitrogen consumptions with increasing tendency.