Abstract

Recovery of high-added-value compounds from seafood waste is a promising area of research. Mussel byssus is a by-product from mussel production for human consumption, which is a potential source of collagen. The goal of this study was to extract collagen from the byssus of Chilean mussel using two methods (acidic and enzymatic) and determine their extraction yields. Acidic extraction was performed by immersing the byssus into distilled water adjusted to pH 4 with HCl at two extraction temperatures (60 or 80 A degrees C) and times (6 or 24 h). For enzymatic extraction, first an enzymatic hydrolysis at two times (4 or 24 h) and pepsin/substrate ratios (1:50 or 4:50) was done. Then, the extraction was conducted at 80 A degrees C for 24 h. All samples were analyzed for total protein, amino acid profile and molecular weight of collagen extracts. Extraction time and temperature had significant effects (p < 0.05) on protein and hydroxyproline contents after acidic extraction, where the higher level of process parameters (80 A degrees C and 24 h) gave the highest protein (6 mg/mL) and hydroxyproline (7.6 mg/g protein) values. Using an enzymatic step before extraction, an increase in protein and hydroxyproline contents was observed, with maximum values of 31 mg/mL and 32 mg/g protein, respectively. The enzyme extraction presented the higher extraction yield, values ranging from 3.86 to 7.56 %. Electrophoretic patterns of collagen presented only beta and gamma bands, suggesting that this collagen is highly cross-linked at the telopeptide region. These results indicate that the Chilean mussel byssus is a good source of collagen that can be extracted for different purposes.