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.

Keywords: Acetobacter aceti, acetification rate, amla (Emblica officinalis Gaertn.), concentrated sugar syrup, fermentation, Saccharomyces cerevisiae, vinegar, waste utilization, yield factor.