Isolation and characterization of acid and pepsin soluble collagen extracted from sharpnose stingray (Dasyatis zugei) skin

This study aimed to isolate and characterize the acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the skin of the sharpnose stingray (Dasyatis zugei). Isolated ASC and PSC were subjected to chemical and physical characterizations. The yield of PSC (34.84±1.26%) was significantly higher than that of ASC (20.48±4.41%) (p<0.05). There were no significant differences between ASC and PSC in terms of chemical composition (p>0.05). Both ASC and PSC were thermally stable at high temperatures, with denaturation temperatures of 24.1°C and 25.2°C, respectively, and maximum temperatures of 31.94±0.13°C and 31.79±0.23°C, respectively. Fourier transform infrared (FTIR) investigations showed the presence of triple helical structure with strong hydrogen bonding in both ASC and PSC. Meanwhile, both collagens were highly solubilized at acidic pH but at different optimal pH. The surface morphologies of ASC and PSC were loose and possessed slender, less uniform and irregular fibrous network structures with large and irregular pores observed between the fibrils. This finding showed that the alternative source of marine collagen possesses good physicochemical properties which highly potential for nutraceutical, pharmaceutical or cosmeceutical application.

Characterization of acid soluble collagen (ASC) and pepsin soluble collagen (PSC) extracted from shortfin scad (Decapterus macrosoma) waste

Fish waste management is one of the biggest impacts towards the environment. However, it is one of the rich sources of protein. Therefore, the aim of this study was to isolate and characterize acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from shortfin scad (Decapterus macrosoma) waste, with the yields of ASC (3.35±3.43%) and PSC (0.10±0.13%) respectively. The isolated ASC and PSC from shortfin scad waste were characterized on chemical composition, protein concentration, structural properties by FTIR, solubility and morphology properties compared to the commercial collagen from tilapia (Oreochromis niloticus) scales. In terms of chemical composition, PSC showed better than ASC, since it contains comparatively higher in protein (26.97±1.02%) by Kjeldahl method and protein concentration (2.69±0.47 mg/mL) by biuret method, compared to ASC. The FTIR investigations also certified the existence of spacial triplehelical structures of collagens that are important for collagen backbones. Solubility results showed that both ASC and PSC are high insolubility at acidic pH with the lowest solubilisation point at the range of alkali condition. The morphological analysis of both ASC and PSC were almost similar too, as there were fibrils and porous structure. Therefore, collagen from shortfin scad waste, could be a useful alternative, with the potential to be used in food ingredient, biomedical, pharmaceutical and nutraceuticals industries