Estimation of Transparency of Pomegranate Juice during its Storage

Abstract

Due to the ever-growing trend of using turbidity and stability indicators as indicators of the quality of fruit juices, the main purpose of our study is to identify the role of pomegranate juice components in processes that are accompanied by the formation of turbid suspensions in them and precipitation during their storage as a finished product.The experiments involved the fruits of 22 varieties and forms of pomegranate from Geokchay district (Azerbaijan), which were subjected to manual processing aimed at extracting juicy grains. Juice was obtained from pomegranate seeds using a juicer-press of the Kenwood JE290 type. The freshly squeezed juices were filtered through a two-layer paper-fabric filter, after which they were poured into glass bottles, processed in a pasteurizer for 30 minutes at a temperature of 75 ° C and transferred to storage at a temperature of 18 ... 22 ° C in a darkened room. Immediately after filtration, their composition was studied by chemical analysis, and after 9 months of storage, the percentage of raw sediment in each juice sample was determined using a method that included separating it using a centrifuge and weighing.The obtained data were processed using the method of correlation analysis aimed at establishing the relationship between the concentration of the analyzed substance and the percentage of sediment.It was discovered that the data on the mass fractions of catechins, ascorbic acid, and protein in freshly squeezed juices and the percentages of precipitation in the juices correlate.The preliminary membrane treatment of juices, which is intended to remove colloids, has found to be effective in increasing the stability of juices.