Food wastes as potential substrates for lactic acid production in open fermentation

Chemical compositions of food wastes collected in Universiti Sains Malaysia were compared against Japanese food wastes. Food waste slurry was fermented in open condition without any sterilization and neither inoculums nor nutrients were added. The relation of glucose to lactic acid with parameters of fermentation time, temperature and initial pH were observed. Highest lactic acid yield for all three parameters were 18.06±4.61, 15.91±1.23 and 24.09±2.34 g/L respectively. When initial pH was set at pH 9, bioconversion of initial glucose to lactic acid was 38.04 % compared to only 30.30 % when initial pH was 7. Lactic acid production showed an increasing trend as initial pH increased from 7 to 9.