ASSESSMENT OF EXTRACTION PROCESS, DEGRADATION KINETICS OF ANTHOCYANIN FROM EGGPLANT (SOLANUM MELONGENA) PEEL AND ITS USE FOR MAKING OF GUAVA JELLY

Abstract

There is a growing attention in natural colorants as an alternative of synthetic colorants which have many biological activities and antioxidant potential on consumer health. The present study deals with the assessment of extraction process and the effects of pH (1.0, 3.0, and 5.0), extraction media (water and 50% ethanol) and storage condition (ambient and refrigeration) on anthocyanin content and degradation kinetics of total anthocyanin in the peel of eggplant. Maximum amount of anthocyanin content was obtained in water and 50% ethanol (247.02 ± 2.98) and (190.51 ± 3.40) mg/100g respectively at pH 3.0 followed by pH 1.0 and pH 5.0. Better results for kinetic parameters (t1/2, %R) were noticed at lower pH for water followed by 50% ethanol at refrigeration temperature. Anthocyanin degradation was accelerated at ambient atmospheric temperature (30 ± 2)° C than in refrigeration storage condition. PH, storage time and temperature affected the stability of anthocyanin. Experience of this research work suggests that anthocyanin from the peel of eggplant may be an excellent source to meet up the increasing need of natural colorants. The extracted anthocyanin from the peel of eggplant was also used to prepare guava jelly and investigate the changes in moisture content, ash content, acidity, reducing sugar, non-reducing sugar, total sugar and total soluble solids (TSS). The result showed that no significant changes in moisture content (28.72 ± 1.64)%, ash content (0.67 ± 0.01)%, acidity (0.35 ± 0.01)%, reducing sugar (27.08 ± 1.98)%, non-reducing sugar (35.81 ± 1.15)%, total sugar (62.89 ± 3.10)% and total soluble solids (66.00 ± 1.00) °brix of guava jelly due to addition of anthocyanin.