The production of citric-acid from Bilimbi (Averrhoa bilimbi) fruits through the fermentation process using Aspergillus niger

Abstract

The aimed of this study was to evaluate the quality of citric acid products made from bilimbi fruits by fermentation method using Aspergillus niger as inoculum at various levels of concentration (3%, 6%, and 9%) and fermentation time (1, 3, 5, and 7 days). The citric acid obtained was then analysed their quality including yield, total sugar content, and citric acid content. There is significantly different of citric acid content as affected by the interaction of inoculum concentration and fermentation period, but no significantly different effect on yield and total sugar of fermentation product. The best fermentation condition for citric acid production from bilimbi fruit juice was 6% inoculum concentration with 5 days fermentation. At this condition the citric acid concentration was 3.33%.