Laboratory of Animal Breeding and Husbandry, Department of Animal Science, Agricultural University of Athens, 118 55 Athens, Greece.
Laboratory of Animal Breeding and Husbandry, Department of Animal Science, Agricultural University of Athens, 118 55 Athens, Greece.
J Dairy Sci. 2024 Feb;107(2):683-694. doi: 10.3168/jds.2023-23643. Epub 2023 Sep 13.
A side effect of the raised consumption of Greek yogurt is the generation of massive amounts of yogurt acid whey (YAW). The dairy industry has tried several methods for handling these quantities, which constitute an environmental problem. Although the protein content of YAW is relatively low, given the huge amounts of produced YAW, the final protein amount in the produced YAW should not be underestimated. Taking into consideration the increased interest for bioactive peptides and the increased demand for dietary proteins, combined with protein and peptides content of YAW, efforts should be made toward reintroducing the latter in the food supply chain. In this context and in view of the prevalent dietary iron deficiency problem, the objective of the present study was the investigation of YAW fractions' effect on Fe bioavailability. With this purpose, an in vitro digest approach, following the INFOGEST protocol, was coupled with the Caco2 cell model. To evaluate whether YAW digest fractions exert positive, negative or neutral effect on Fe bioavailability, they were compared with the ones derived from milk, a well-studied food in this context. Milk and YAW showed the same effectiveness on both Fe bioavailability and the expression of relative genes (DCYTB, DMT1, FPN1, and HEPH). Focusing further on YAW fractions, by comparison with their blank digest control counterparts, it resulted that YAW 3- to 10-kDa digests fraction had a superior effect over the 0- to 3-kDa fraction on Fe-uptake, which was accompanied by a similar effect on the expression of Fe metabolism-related genes (DCYTB, FPN1, and HEPH). Finally, although the 3- to 10-kDa fraction of bovine YAW digests resulted in a nonsignificant increased Fe uptake, compared with the ovine and caprine YAW, the expression of DCYTB and FPN1 genes underlined this difference by showing a similar pattern with statistically significant higher expression of bovine compared with ovine and bovine compared with both ovine and caprine, respectively. The present study deals with the novel concept that YAW may contain factors affecting Fe bioavailability. The results show that it does not exert any negative effect and support the extensive investigation for specific peptides with positive effect as well as that YAW proteins should be further assessed on the prospect that they can be used in human nutrition.
希腊酸奶消耗量的增加带来了一个副作用，即产生大量的酸奶酸乳清（YAW）。乳制品行业已经尝试了几种处理这些数量的方法，但这构成了一个环境问题。尽管 YAW 的蛋白质含量相对较低，但考虑到产生的 YAW 数量巨大，最终产生的 YAW 中的蛋白质含量不应被低估。考虑到人们对生物活性肽的兴趣增加和对膳食蛋白质的需求增加，以及 YAW 的蛋白质和肽含量，应努力将后者重新引入食品供应链中。在这种情况下，考虑到普遍存在的膳食铁缺乏问题，本研究的目的是研究 YAW 馏分对 Fe 生物利用度的影响。为此，采用体外消化方法，遵循 INFOGEST 协议，与 Caco2 细胞模型相结合。为了评估 YAW 消化馏分对 Fe 生物利用度是产生积极、消极还是中性影响，将它们与牛奶（这是该领域中研究较好的一种食品）的衍生馏分进行比较。牛奶和 YAW 对 Fe 生物利用度和相对基因（DCYTB、DMT1、FPN1 和 HEPH）的表达具有相同的效果。进一步关注 YAW 馏分，与它们的空白消化对照物相比，结果表明，YAW 3-10 kDa 消化馏分在铁摄取方面的效果优于 0-3 kDa 馏分，这伴随着对铁代谢相关基因（DCYTB、FPN1 和 HEPH）表达的类似影响。最后，尽管与绵羊和山羊 YAW 相比，牛 YAW 消化 3-10 kDa 馏分的铁摄取量没有显著增加，但 DCYTB 和 FPN1 基因的表达强调了这一差异，表明牛与绵羊和牛与绵羊和山羊相比，基因表达均具有统计学意义上更高的表达。本研究涉及一个新的概念，即 YAW 可能含有影响 Fe 生物利用度的因素。结果表明，它不会产生任何负面影响，并支持对具有积极影响的特定肽进行广泛研究，同时也应进一步评估 YAW 蛋白，以期将其用于人类营养。
