Enzymatic hydrolysis of camel milk casein and its antioxidant properties

Abstract

The aim of this work was to investigate the enzymatic hydrolysis of whole casein from camel milk with proteolytic enzymes, viz. alcalase, α-chymotrypsin and papain, and to assess the antioxidant activity of hydrolysates. Casein powder was reconstituted (5% TS) and the selected enzymes were added at 1:100 (enzyme/substrate). Hydrolysis was carried out for 6 h at 55°C for alcalase and papain and 37°C for α-chymotrypsin, and samples were drawn at 2-h interval. The hydrolysates were analysed for pH, degree of hydrolysis (DH) and antioxidant activities, viz. 2, 2′-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), 2, 2′-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay. The decrease in pH of the hydrolysates was observed with the progress of hydrolysis time, and as compared to alcalase, the rate of pH decrease was higher for α-chymotrypsin and papain. The DH increased significantly (P<0.05) up to 6 h on hydrolysis with alcalase and papain, whereas with chymotrypsinolysis, DH increased significantly (P<0.05) up to 4 h; thereafter, a non-significant increase was observed. The antioxidant activity assessed by ABTS, DPPH and FRAP assay increased significantly (P<0.05) with the increase in hydrolysis time as well as the degree of hydrolysis. The chymotrypsinolysis exhibited higher antioxidant activity as compared to alcalase and papain. The results obtained in this study suggested that camel milk casein could be used as an ingredient in nutraceuticals or health-oriented foods.

Camel Milk: An Important Natural Adjuvant

“…Camel b-CN showed high antioxidant activity after hydrolysis with chymotrypsin. The results of this study suggest that when camel milk is consumed and digested, the produced peptides start to act as natural antioxidants [65,66,101].…”

“…There are reports that camel milk acts as an adjuvant and has medicinal properties, suggesting it contains protective proteins, which may have possible role for enhancing immune defense mechanism [120]. These potential health benefits are obtained through a number of bioactive components in camel milk [63,65]. These components either exist naturally in camel milk or are derived from camel milk protein hydrolysates using proteolytic enzymes and/or fermentation with lactic acid bacteria (LAB) [64,66].…”

“…After enzymatic hydrolysis, antioxidant activities of camel whole casein [65] and camel b-CN were enhanced. Camel b-CN showed high antioxidant activity after hydrolysis with chymotrypsin.…”

Effect of Heat Treatment and Fermentation on Bioactive Behavior in Yoghurt Made from Camel Milk

“…This may be due to the pro-oxidant effects of bioactive peptides produced after fermentation of camel milk and presence of functional groups such as hydroxyl groups on phenolic compounds [59]. Also, demonstrated that a number of food-derived peptides were capable of interacting and quenching DPPH radicals [10,60]. Escherichia coli (ACCT 8739)…”

“…Addition to, the bioactive peptides are used as health-promoting food supplements or as food grade bio-preservatives in the food industry. The common source of bioactive peptides is egg proteins [8], muscle protein, plant proteins, fish proteins [9], casein [10] and whey proteins [8].…”