Abstract:
This research aimed to screen the lactic acid bacteria (LAB) from fermented foods and apply to the fermentation process of shrimp wastes for chitin, astaxanthin and protein hydrolysate production. The results indicated that 33 isolates of LAB were isolated from pickled fish (PF), sour pork (SP) and pickled bamboo shoot (PBS). Three isolates of LAB were selected to ferment shrimp wastes. Five hundred grams of minced shrimp waste was mixed with 10% of sucrose, 5% of selected LAB and fermented at 37 C for 24 h. After fermentation process, the ensilage was centrifuged to separate solid (chitin) and liquid (protein hydrolysate). The chitin product was analyzed for the glucosamine and the astaxanthin content and the protein hydrolysate was analyzed for the total amino acid content. The analysis results showed that the highest amount of glucosamine was detected from the chitin by fermenting shrimp shell with PBS, equal to 21.92±5.59 mg/g. For the astaxanthin, the highest amount of astaxanthin was detected from the chitin by fermenting shrimp head with PF, equal to 2.95±1.44 µg/g. Total amino acid and essential amino acid content were found in protein hydrolysate from the fermentation by LAB more than the control without LAB. The proportion of essential amino acid to total amino acid in the protein hydrolysate from the fermentation by PBS was maximum, equal to 42.8%. Glutamic acid was predominantly found in all protein hydrolysate and the highest amount was found in protein hydrolysate from the fermentation by PBS, equal to 1455.91 mg/ 100 g. From all results, it indicated that the fermentation shrimp waste with LAB was the choice to decrease the chemical utilization and could add the value of agricultural wastes.