Laboratório de Bioquímica e Microbiologia Aplicada, Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS, Brazil.
J Sci Food Agric. 2011 Sep;91(12):2247-54. doi: 10.1002/jsfa.4446. Epub 2011 May 10.
Bioactive peptides might be released from precursor proteins through enzymatic hydrolysis. These molecules could be potentially employed in health and food products. In this investigation, ovine milk caseinate hydrolysates obtained with a novel microbial protease derived from Bacillus sp. P7 were evaluated for antioxidant, antimicrobial, and angiotensin I-converting enzyme (ACE)-inhibitory activities.
Antioxidant activity measured by the 2,2'-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid method increased with hydrolysis time up to 2 h, remaining stable for up to 4 h. Hydrolysates showed low 2,2-diphenyl-1-picrylhydrazyl radical-scavenging abilities, with higher activity (31%) reached after 1 h of hydrolysis. Fe(2+) -chelating ability was maximum for 0.5 h hydrolysates (83.3%), decreasing thereafter; and the higher reducing power was observed after 1 h of hydrolysis. ACE-inhibitory activity was observed to increase up to 2 h of hydrolysis (94% of inhibition), declining afterwards. 3 h hydrolysates were shown to inhibit the growth of Bacillus cereus, Corynebacterium fimi, Aspergillus fumigatus, and Penicillium expansum.
Ovine caseinate hydrolyzed with Bacillus sp. P7 protease presented antioxidant, antihypertensive, and antimicrobial activities. Hydrolysis time was observed to affect the evaluated bioactivities. Such hydrolysates might have potential applications in the food industry.
生物活性肽可能通过酶解从前体蛋白中释放出来。这些分子可能被应用于健康和食品产品中。在这项研究中，用一种新型来源于芽孢杆菌的微生物蛋白酶对绵羊乳清酪蛋白水解物进行了评估，以研究其抗氧化、抗菌和血管紧张素转化酶（ACE）抑制活性。
通过 2,2'-偶氮双（3-乙基苯并噻唑啉-6-磺酸）法测定的抗氧化活性随着水解时间的增加而增加，在 4 小时内保持稳定。水解产物对 2,2-二苯基-1-苦基肼自由基的清除能力较低，水解 1 小时后活性达到 31%。Fe(2+)螯合能力在 0.5 小时水解物中达到最大值（83.3%），之后下降；1 小时水解物的还原能力较高。ACE 抑制活性随着水解时间的增加（抑制 94%）而增加，之后下降。3 小时水解物被证明可以抑制蜡状芽孢杆菌、藤仓氏菌、烟曲霉和扩展青霉的生长。
用芽孢杆菌蛋白酶水解的绵羊乳清酪蛋白具有抗氧化、降血压和抗菌活性。水解时间影响评价的生物活性。这种水解产物可能在食品工业中有潜在的应用。
