Chay Pak Ting Bertrand P, Mine Yoshinori, Juneja Lekh R, Okubo Tsutomu, Gauthier Sylvie F, Pouliot Yves
Institute of Nutraceuticals and Functional Foods (INAF), Department of Food Science and Nutrition, Université Laval, Québec, QC, G1V 0A6, Canada.
Department of Food Science, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Membranes (Basel). 2011 Jul 6;1(3):149-61. doi: 10.3390/membranes1030149.
The objective of the study was to compare the antioxidant activity of two distinct hydrolysates and their peptide fractions prepared by ultrafiltration (UF) using membranes with molecular weight cut-off of 5 and 1 kDa. The hydrolysates were a delipidated egg yolk protein concentrate (EYP) intensively hydrolyzed with a combination of two bacterial proteases, and a phosphoproteins (PPP) extract partially hydrolyzed with trypsin. Antioxidant activity, as determined by the oxygen radical absorbance capacity (ORAC) assay, was low for EYP and PPP hydrolysates with values of 613.1 and 489.2 µM TE×g-1 protein, respectively. UF-fractionation of EYP hydrolysate increased slightly the antioxidant activity in permeate fractions (720.5-867.8 µM TE×g-1 protein). However, ORAC values were increased by more than 3-fold in UF-fractions prepared from PPP hydrolysate, which were enriched in peptides with molecular weight lower than 5 kDa. These UF-fractions were characterized by their lower N/P atomic ratio and higher phosphorus content compared to the same UF-fractions obtained from EYP-TH. They also contained high amounts of His, Met, Leu, and Phe, which are recognized as antioxidant amino acids, but also high content in Lys and Arg which both represent target amino acids of trypsin used for the hydrolysis of PPP.
本研究的目的是比较两种不同水解产物及其通过超滤（UF）制备的肽级分的抗氧化活性，超滤使用截留分子量为5 kDa和1 kDa的膜。水解产物一种是用两种细菌蛋白酶组合强烈水解的脱脂蛋黄浓缩蛋白（EYP），另一种是用胰蛋白酶部分水解的磷蛋白（PPP）提取物。通过氧自由基吸收能力（ORAC）测定法测定，EYP和PPP水解产物的抗氧化活性较低，分别为613.1和489.2 μM TE×g-1蛋白。EYP水解产物的超滤分级分离使渗透级分中的抗氧化活性略有增加（720.5 - 867.8 μM TE×g-1蛋白）。然而，从PPP水解产物制备的超滤级分中ORAC值增加了3倍以上，这些级分富含分子量低于5 kDa的肽。与从EYP-TH获得的相同超滤级分相比，这些超滤级分的特征在于其较低的N/P原子比和较高的磷含量。它们还含有大量的His、Met、Leu和Phe，这些被认为是抗氧化氨基酸，但Lys和Arg的含量也很高，这两种氨基酸都是用于水解PPP的胰蛋白酶的靶标氨基酸。
