The low yield of ASC might be due to many interchain cross-links (covalent bonds) formed via condensation reaction of aldehyde with lysine and hydroxylysine the telopeptide region, leading to the lesser solubility of collagen in acid. The higher yield of pepsin soluble collagen suggested that pepsin zyme facilitated the collagen extraction via the cleavage of telopeptide re- gion. The pepsin extraction cleaves the collagen telopeptides and releases molecules polymerized by the acid-stable cross-links. As well as the inter-molecular cross-linking, leading to a decrease in solubility of colla- gen under acidic condition. Pepsin was able to specifically cleave the telopeptide region of collagen. The cross-linked regions at the telopeptide could be cleaved by pepsin without damaging the integrity of the triple helix, resulting in the increased collagen extraction efficacy (Jia et al., 2012; Li et al., 2013; Veeruraj, Arumugam, & Balasubramanian, 2013). The extractability of the ASC and PSC in fish skin also depends the cies and cross-linking of collagen fibrils. The result of the study indicated the potential pepsin digestion to increase the yield of collagen extracted from the skin of Indian carps.