Evaluation of the effect of acidic and enzymatic extraction methods on collagen recovery from parrot fish (Scarus ghobban) skin and evaluation of their structural, chemical, antioxidant and functional properties

In the present study, the effect of acidic and enzymatic extraction of collagen from fish parrot skin was investigated. The results of extraction efficiency showed that the enzymatic method was three times more effective than acidic method. FTIR and SEM tests were used to further investigate the obtained collagens. The results showed that amides A and B appeared in similar regions for the obtained samples. Also, enzymes extracted by enzymatic method (PSC) had a more regular structure than collagen extracted by acidic method (ASC). The electrophoresis pattern of the extracted collagens revealed that the obtained collagens were type I and consisted of two 1α chains and one 2α chain with a density of 1α greater than 2α. The results of the percentage of neutralization of DPPH free radicals of the obtained collagens showed that among the concentrations of 0.1, 0.01 and 0.001 the highest concentration had the best performance and for ASC sample 34.35% and in the sample (ASCH) It was 53.86 % (P<0.05). Examination of emulsifying properties (EAI) of the obtained samples showed that both samples in acidic conditions showed higher emulsifying activity, the highest value of this index in acidic collagen 67.48% and enzymatic collagen 32/17%, respectively (P<0.05). The results of emulsion stability showed that hydrolyzed collagen samples at all pHs showed higher performance than non-hydrolyzed samples (P<0.05). The solubility of the samples was different at different pHs and the highest solubility of the samples was acidic pH with 2.38% for acidic collagen and 5.3% for enzymatic collagen (P<0.05). The results showed that the enzymatic method can have a better performance in extracting collagen from the skin of Scarus ghobban fish and also the obtained collagen can be used for food and cosmetic applications.