P. JAYAMMA, M. KEERTHI BAI, R. ARUNA, Y. ALEKHYA REDDY, M. SOWJANYA AND Y. NAVYA SREE
Abstract
The fruit waste of pineapple peel and jackfruit rag contains rich amount of carbohydrates can be tuned as substrates for the cultivation of bacteria and fungi. These wastes were also used as raw material for production of lactic acid. Increasing demand of lactic acid in food, bakery, pharmaceutical and cosmetic industries etc., had made it necessary to develop a sustainable and conventional method for lactic acid production by fermentation. The present study aimed for lactic acid production from pineapple peel and jackfruit rag. A total of 15 isolates were isolated from different fruit wastes by streak plate method and were identified as Lactic acid bacteria based on gram staining and biochemical tests. The physicochemical properties of pineapple peel and jackfruit rag were: pH (4.3 and 6.2), TSS in brix (12 and 19.5), moisture content (83.8% and 80%), respectively. Different pre-treatment methods were employed for the extraction of reducing sugars from pineapple peel and jackfruit rag. Among six pre-treatments, the substrate with 1 per cent hydrochloric acid followed by autoclave resulted the highest value of reducing sugars. The lactic acid production was carried out by inoculating the 5% lactic acid bacterial isolates (MM, G1 and A2) in acid hydrolysate of substrates and incubated at 30 ºC with 120 rpm for three days. Maximum Lactic acid yield was recorded with pineapple peel substrate (3.15%) than jackfruit rag (2.7%) after 3 days of incubation with MM isolate. This study highlights the potential of pineapple peel and jackfruit rag waste as a low cost and economically viable fermentation substrate for the production of lactic acid.