Development of sublimation drying modes of rose hip fruits Freezing drying of rose hip

Abstract

The aim of the study was the selection of effective modes of rosehip sublimation dehydration. An Iney-6M unit was used for freeze drying. The selection of the duration of the sublimation stage and the final drying temperature was carried out. At the same time, such indicators as the duration of drying, organoleptic assessment and the preservation of vitamin C were analyzed. The duration of freeze drying of rose hips with a period of sublimation of 4, 5, 6 and 7 hours was 6, 7, 8 and 8.5 hours, respectively. It was found that with a decrease in the duration of the sublimation stage, a decrease in the quality characteristics of dry rose hips is observed. It was found that when the drying temperature changes from 70 to 40 °C, the drying time increases from 6.5 to 9.5 hours. At the same time, the loss of vitamin C also decreases. Based on the research, the most favorable modes of sublimation dehydration of rose hips have been determined - the final drying temperature is 50 °C and the duration of the sublimation stage is 5 hours. Under these modes, the duration of lyophilization is 8 hours, the total organoleptic assessment is 18.25 points out of 20, and the preservation of vitamin C is 27%. Lyophilized rose hips can be used as an independent product, or ground into powder for adding to other products - confectionery, dairy, bakery products, as well as biologically active additives and functional food.