Development of a Fermentation Process for Utilization of Emblica Officinalis Gaertn (Amla) Candy Waste for Production of Natural Vinegar

Abstract

Emblica officinalis Gaertn (amla) fruit while being processed into candy by food processing industry generates a high brix candy syrup which otherwise is a waste and poses burden to environment. This candy syrup was converted into natural vinegar, a nutrient rich value added food product through two successive fermentations: alcoholic and acetic acid fermentations. Diluted candy syrup (20°Bx) supplemented with raisins was fermented to ethanol by using Saccharomyces cerevisiae strain 35 which produced 10.5% (v/v) ethanol in 28 days. The ethanol was further used for production of amla-candy syrup vinegar using cells of Acetobacter aceti NRRL 746. The wort (supplemented with mother vinegar and nutrients in the form of sulphates and nitrogen substrates) with initial acidity of 2% was fermented by A.aceti @7.5% (v/v) and mother vinegar @ 10% (v/v) at 5L scale. This resulted in production of vinegar with a final acidity of 5.7% (w/v) in 14 days having a fermentation efficiency of 75.5±8.21%, acetification rate of 4.11±0.36g/L/d and a yield factor of 0.95±0.07. The fermented vinegar so produced had 180mg/100ml of total phenols and 390mg/100ml ascorbic acid, making it a value added product from an otherwise amla waste.