Lyophilization effect on rosehip extract physico-chemical properties

Abstract

Concentrated products feature a longer shelf life, easier transportation because of lower weight, and a shorter recovery time. Many food products, in particular beverages, are thermolabile. When they are exposed to high temperatures, their native properties are lost, the chemical composition changes and the quality may deteriorate. Therefore, concentrates of such products benefit from low temperatures treatment. Lyophilization, or vacuum freeze-drying, allows to effectively preserve physico-chemical properties of raw materials in food concentrates and avoid high temperatures treatment. Nowadays, plant extracts are used as important additives in the food industry due to their content in biologically active substances such as polyphenolic compounds, which have antioxidant activity and play an important role in the fight against free radicals. A plant that possesses polyphenols in its chemical composition is rosehip. The article describes experiments conducted to study the effect of lyophilization on the change in physico-chemical properties of rosehip fruit extract. An analysis was carried out to evaluate the dry matter concentration, total content of polyphenolic compounds, chromaticity, turbidity and pH losses of the extract under the developed mode of lyophilization. Based on the research results, lyophilization allows to obtain the concentrated rosehip extract with a high level of preservation of the dry matter concentration, total content of polyphenols, chromaticity, turbidity and pH.