Shock freezing of edible honeysuckle berries for obtaining biologically active dietary ingredients

Abstract

Edible honeysuckle berries are a unique source of the most important biologically active substances for human beings. Shock freezing of these berries will provide the food industry with raw materials for enriching many products with physiologically functional ingredients of honeysuckle berries. To determine the suitability of edible honeysuckle berries for freezing the varieties were selected that have the highest quality, providing the daily requirement of the human beeing with biologically active substances and antioxidants, characterized by a high content of soluble solids, sugars, protopectin (at least 0.5%). Screening of berries according to these indicators revealed that these requirements were met by varieties Goluboi Desert, Zhimorodok, Goluboe Vereteno. They were used in our shock freezing experiments. The optimum temperature for shock freezing of honeysuckle berries has been determined experimentally - minus 35ºС. The berries were frozn in a fluidized freezing apparatus in a vibro-boiling layer 4 cm thick at -35ºС to the final temperature in the berry flesh minus 20ºС. This temperature provides the minimum loss of biologically active substances of honeysuckle berries during the shock freezing process and preservation of their properties during the following long-term storage at -18ºC. Organoleptic, physico-chemical and microbiological parameters of frozen berries have been determined. The changes in these indicators in the process of berry storage have been revealed. The maximum storage time of frozen berries without significant changes in their consumer properties, which is 12 months, has been established.