Sakkas Lambros, Lekaki Eleni, Moatsou Golfo
Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece.
Foods. 2022 Jul 15;11(14):2103. doi: 10.3390/foods11142103.
Tryptic WPHs with considerable residual whey protein content intact were developed from two sheep/goat WPCs (65% and 80% protein) without pH control. Pasteurization was used to avoid denaturation. Changes in non-protein nitrogen (DH_TCASN), free amino groups (DH_TNBS), and major whey proteins were used to investigate the degree and extent of hydrolysis. Antihypertensive potential (ACE-IA), radical scavenging (DPPH-RSA), and iron chelation (Fe-CA) were assessed. No statistically significant changes in pH (5.84−6.29) were observed during hydrolysis and storage. At the start of hydrolysis, DH_TCASN was ≅11% for both substrates whereas DH_TNBS was >10% and >5% for WP65 and WP80, respectively. After one-hour hydrolysis, DH_TCASN was ≅17% for both substrates and DH_TNBS was ≅15% and ≅11% for WP65 and WP80, respectively. The β-lactoglobulin, α-lactalbumin, and caseinomacropeptide of WP65 were hydrolyzed by 14 ± 1.3%, 73.9 ± 2.6% and 37 ± 2.6%. The respective values for WP80 were 14.9 ± 1.7%, 79.9 ± 1%, and 32.7 ± 4.8%. ACE-IA of the hydrolysates of both substrates was much higher (>80%) than that of controls (<10%). Hydrolysis, substrate type, and storage did not affect the DPPH-RSA (45−54%). Fe-CA of the WP65 and WP80 hydrolysates were ≅40% and ≅20%, respectively; a similar outcome was found in the respective controls. Refrigerated storage for 17 h did not affect the degree of hydrolysis and biofunctional activities.
在不控制pH值的情况下，由两种绵羊/山羊乳清蛋白浓缩物（蛋白质含量分别为65%和80%）制备了具有相当数量完整残留乳清蛋白的胰蛋白酶水解乳清蛋白水解物。采用巴氏杀菌法避免变性。通过非蛋白氮（DH_TCASN）、游离氨基（DH_TNBS）的变化以及主要乳清蛋白的变化来研究水解程度和范围。评估了降压潜力（ACE-IA）、自由基清除能力（DPPH-RSA）和铁螯合能力（Fe-CA）。在水解和储存过程中未观察到pH值（5.84−6.29）有统计学显著变化。水解开始时，两种底物的DH_TCASN均约为11%，而WP65和WP80的DH_TNBS分别>10%和>5%。水解1小时后，两种底物的DH_TCASN均约为17%，WP65和WP80的DH_TNBS分别约为15%和约为11%。WP65的β-乳球蛋白、α-乳白蛋白和酪蛋白巨肽分别水解了14±1.3%、73.9±2.6%和37±2.6%。WP80的相应值分别为14.9±1.7%、79.9±1%和32.7±4.8%。两种底物水解产物的ACE-IA均远高于对照组（>80%对<10%）。水解、底物类型和储存均不影响DPPH-RSA（45−54%）。WP65和WP80水解产物的Fe-CA分别约为40%和约为20%；在各自的对照组中也发现了类似结果。冷藏储存17小时不影响水解程度和生物功能活性。
