Trigueros Lorena, Wojdyło Aneta, Sendra Esther
IPOA Research Group (UMH-1 and REVIV_Generalitat Valenciana), Departamento de Tecnología Agroalimentaria, Universidad Miguel Hernández , Ctra. de Beniel km 3.2, 03300 Orihuela, Alicante, Spain.
J Agric Food Chem. 2014 Jul 9;62(27):6417-25. doi: 10.1021/jf501503h. Epub 2014 Jun 26.
Pomegranate juice (PGJ) is rich in phenolics which are potent antioxidants but also prone to interact with proteins. A yogurt rich in PGJ (40%) made from arils was elaborated (PGY) to determine the antioxidant activity and to estimate the phenolics-proteins interaction during 28 days of cold storage. Juice, yogurts, and protein-free permeates were analyzed for phenolic composition. Yogurt fermentation modified the anthocyanin profile of the initial PGJ, especially the content in cyanidin-3-O-glucoside. During storage, individual anthocyanin content in PGY decreased but it did not modify yogurt color. The analysis of permeates revealed that the degree of phenol-protein interaction depends on the type of phenolic, ellagic acid and dephinidin-3,5-O-diglucoside being the least bound phenolic compounds. The presence of PGJ in yogurt enhanced radical scavenging performance, whereas all the observed ferric reducing power ability of PGY was strictly due to the PGJ present. The 84.73% of total anthocyanins remained bound to proteins at the first day of storage and 90.06% after 28 days of cold storage, revealing the high affinity of anthocyanins for milk proteins.
石榴汁（PGJ）富含酚类物质，这些酚类物质是强效抗氧化剂，但也容易与蛋白质相互作用。制备了一种由石榴籽制成的富含PGJ（40%）的酸奶（PGY），以测定其抗氧化活性，并评估冷藏28天期间酚类物质与蛋白质的相互作用。对果汁、酸奶和无蛋白渗透物进行了酚类成分分析。酸奶发酵改变了初始PGJ的花青素谱，尤其是矢车菊素-3-O-葡萄糖苷的含量。在储存期间，PGY中单个花青素的含量下降，但并未改变酸奶的颜色。对渗透物的分析表明，酚类物质与蛋白质的相互作用程度取决于酚类物质的类型，鞣花酸和飞燕草素-3,5-O-二葡萄糖苷是结合最少的酚类化合物。酸奶中PGJ的存在增强了自由基清除性能，而PGY所有观察到的铁还原能力完全归因于其中存在的PGJ。储存第一天，84.73%的总花青素与蛋白质结合，冷藏28天后这一比例为90.06%，这表明花青素与乳蛋白具有高亲和力。
