An investigation into copper-binding capacity of the white leg shrimp head (Litopenaeus vannamei) protein hydrolysate

The aim of this study is to obtain the copper-binding protein hydrolysate from the white leg shrimp head (WLSH) by-product using enzymatic hydrolysis. The outcome indicated that the copper-binding capacity (CBC) of the WLSH protein hydrolysate achieved the maximum value of 19.4±0.5 mg Cu2+/g protein with hydrolysis conditions including Flavourzyme preparation, pH 7.5, 50°C, the enzyme:substrate (E:S) ratio of 80 U/g protein and 5h of hydrolysis. Under the pH treatment in a range of 1-11 or heat treatment at 100°C for up to 180 min, its CBC remained over 80%. The water holding capacity (WHC) and the oil-holding capacity (OHC) of the protein hydrolysate were 4.1±0.1 ml water/g protein hydrolysate powder and 4.5±0.1 ml oil/g protein hydrolysate powder, respectively. The solution also encompassed up to 8 essential amino acids, accounting for 36.1% of the total amino acid content. The protein hydrolysate could serve not only as a copper chelating agent, preventing copper-deficient or superfluous relating diseases, but also as a texturizer and an amino acid supplement fortified in various types of food.