Enzymatic isolation of carotenoid-protein complex from shrimp head waste and its use as a source of carotenoids

Nearly 150,000–175,000 Gg of shrimp waste per annum is generated from shrimps-processing companies in India. Shrimp waste is a rich sources of protein, chitin and carotenoids. The extracting carotenoids from shrimp waste by using different proteolytic enzymes gave improved extraction of carotenoids and maximum yield over the traditional, solvent extraction process and SC–CO2 extraction. Trypsin recovered highest amount of carotenoids from all types of head wastes, but pepsin and papain also showed good recoveries of carotenoids. The percent of recovery varied with the raw materials and the trend was Penaeus indicus>Penaeus monodon (culture)>Metapenaeus monocerous>Penaeus monodon (wild). The loss of carotenoids during processing of frozen carotenoid-protein cake (CPC) to freeze-dried product was noticed in all trials. Astaxanthin was the main stable pigment and its proportion in total carotenoids increased in freeze-dried product with the loss of minor carotenoids such as β-carotene and their derivatives. The predominance of astaxanthin in the carotenoids indicates that the both frozen CPC and freeze-dried CPC are good source of natural antioxidant and also natural carotenoids.