Dalaka Eleni, Stefos Georgios C, Politis Ioannis, Theodorou Georgios
Laboratory of Animal Breeding and Husbandry, Department of Animal Science, Agricultural University of Athens, 11855 Athens, Greece.
Antioxidants (Basel). 2023 Dec 18;12(12):2130. doi: 10.3390/antiox12122130.
Yogurt acid whey (YAW) is a by-product of Greek strained yogurt production. The disposal of YAW constitutes an environmental problem, and given the increasing demand of Greek yogurt worldwide, its handling is a challenge. However, whey-derived peptides, resulting from microbial fermentation as well as those resulting from further hydrolysis during the digestion process, have been linked to enhanced biological activities. In this study, the antioxidant capacity of 33 samples of YAW obtained from Greek dairy companies of bovine, ovine or caprine origin was investigated using both cell-free and cell-based assays. The YAW samples, their in vitro digestion products (YAW-Ds) and a fraction of the digests (less than 3 kDa; YAW-D-P3) were assessed using four biochemical assays, namely ORAC, ABTS, FRAP and P-FRAP. Our data revealed a higher antioxidant capacity for digested samples compared with undigested samples, with all four methods. ORAC values after in vitro digestion were higher for the ovine samples compared to their bovine (YAW-D and YAW-D-P3) and caprine (YAW-D-P3) counterparts. Furthermore, the YAW-D-P3 fraction derived from samples collected in the summer months exhibited higher ORAC values when compared to the respective fraction from the winter months' samples. The cellular antioxidant activity of ovine YAW-D-P3 was improved in HO-treated HT29 cells compared to the control HO-treated cells. However, YAW-D-P3 could not trigger either the pathways involving the transcription factors NF-κB or NFE2L2 or the gene expression of SOD1, CAT and HMOX1 in LPS-challenged THP-1-derived macrophages. These results suggest that YAW, and particularly YAW from ovine origin, could be used as a natural source for its antioxidant potential in human and animal nutrition.
酸奶酸乳清（YAW）是希腊滤过酸奶生产过程中的副产品。YAW的处理构成了一个环境问题，并且鉴于全球对希腊酸奶的需求不断增加，其处理是一项挑战。然而，微生物发酵产生的以及在消化过程中进一步水解产生的乳清衍生肽与增强的生物活性有关。在本研究中，使用无细胞和基于细胞的测定方法，对从希腊乳制品公司获得的33份牛、羊或山羊来源的YAW样品的抗氧化能力进行了研究。使用四种生化测定方法，即氧自由基吸收能力（ORAC）、2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸（ABTS）、铁离子还原抗氧化能力（FRAP）和磷-FRAP，对YAW样品、其体外消化产物（YAW-Ds）和一部分消化物（小于3 kDa；YAW-D-P3）进行了评估。我们的数据显示，与未消化样品相比，所有四种方法均显示消化样品具有更高的抗氧化能力。体外消化后，绵羊样品的ORAC值高于其牛（YAW-D和YAW-D-P3）和山羊（YAW-D-P3）对应样品。此外，与冬季月份样品的相应部分相比，夏季月份收集的样品衍生的YAW-D-P3部分表现出更高的ORAC值。与对照过氧化氢（HO）处理的细胞相比，HO处理的HT29细胞中绵羊YAW-D-P3的细胞抗氧化活性有所提高。然而，YAW-D-P3在脂多糖（LPS）刺激的THP-1衍生巨噬细胞中不能触发涉及转录因子核因子κB（NF-κB）或核因子E2相关因子2（NFE2L2）的途径以及超氧化物歧化酶1（SOD1）、过氧化氢酶（CAT）和血红素加氧酶1（HMOX1）的基因表达。这些结果表明，YAW，特别是绵羊来源的YAW，因其在人类和动物营养中的抗氧化潜力，可作为一种天然来源。
