Thamamsena Rommanee, Liu Deng Cheng
Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan.
Asian-Australas J Anim Sci. 2020 Sep;33(9):1487-1496. doi: 10.5713/ajas.19.0361. Epub 2019 Dec 24.
The objective of this study was to look for optimal preparation of hydrolysates of desalted duck egg white powder (DDEWP) by the three different proteases and to investigate their antioxidant and antimicrobial properties.
DDEWP was hydrolyzed by three proteases, including pepsin (PEP), Bacillus spp. (BA) and natokinase (NAT) with three different enzyme concentrations (0.1%, 0.3%, and 0.5%), individually. The important key hydrolysis parameters such as hydrolysis degree, yield, antioxidant and antimicrobial activity were evaluated in this experiment.
The results showed that the degree of hydrolysis (DH) of all treatments increased with increasing hydrolysis time and protease concentrations. The antioxidant and antimicrobial activities of the hydrolysates were affected by type and concentration of protease as well as hydrolysis time. Hydrolysis of PEP significantly (p<0.05) obtained the highest yield of hydrolysates, however, both of BA and NAT showed substantially lower DH values and still did not exceed 5% by the end of hydrolysis. Among the different hydrolysates, PEP exhibited significantly higher 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than BA and NAT. All DDEWP hydrolysates from PEP had low ferrous ion chelating activity (<37%) that was significantly lower than that of NAT (>37% to 92%) and BA (30% to 79%). Besides, DDEWP hydrolysates of PEP presented significantly higher reducing power than BA and NAT. In antimicrobial activities, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa were not effectively inhibited by any DDEWP hydrolysates of PEP except for Staphylococcus aureus. Especially, the excellent antibacterial activity against S. aureus only was displayed in DDEWP hydrolysates of PEP 0.1%.
DDEWP hydrolysates from PEP demonstrated significantly better DH, yield, DPPH radical scavenging activity and reducing power, furthermore, had excellent inhibitory on S. aureus due to large clear zone and moderated inhibitory in bactericidal inhibition.
本研究旨在探寻三种不同蛋白酶对脱盐鸭蛋清粉（DDEWP）水解产物的最佳制备方法，并研究其抗氧化和抗菌性能。
用三种蛋白酶分别对DDEWP进行水解，这三种蛋白酶包括胃蛋白酶（PEP）、芽孢杆菌属（BA）和纳豆激酶（NAT），各自采用三种不同的酶浓度（0.1%、0.3%和0.5%）。本实验评估了诸如水解度、产率、抗氧化和抗菌活性等重要的关键水解参数。
结果表明，所有处理的水解度（DH）均随水解时间和蛋白酶浓度的增加而提高。水解产物的抗氧化和抗菌活性受蛋白酶类型、浓度以及水解时间的影响。PEP水解显著（p<0.05）获得了最高的水解产物产率，然而，BA和NAT在水解结束时的DH值均显著较低，仍未超过5%。在不同的水解产物中，PEP表现出比BA和NAT显著更高的2,2-二苯基-1-苦基肼（DPPH）自由基清除活性。来自PEP的所有DDEWP水解产物的亚铁离子螯合活性较低（<37%），显著低于NAT（>37%至92%）和BA（30%至79%）。此外，PEP的DDEWP水解产物表现出比BA和NAT显著更高的还原力。在抗菌活性方面，除金黄色葡萄球菌外，PEP的任何DDEWP水解产物均未有效抑制大肠杆菌、鼠伤寒沙门氏菌和铜绿假单胞菌。特别是，仅在0.1%的PEP的DDEWP水解产物中显示出对金黄色葡萄球菌的优异抗菌活性。
来自PEP的DDEWP水解产物表现出显著更好的DH、产率、DPPH自由基清除活性和还原力，此外，由于有较大的透明圈且杀菌抑制作用适中，对金黄色葡萄球菌具有优异的抑制作用。
