Milinčić Danijel D, Stanisavljević Nemanja S, Kostić Aleksandar Ž, Gašić Uroš M, Stanojević Slađana P, Tešić Živoslav Lj, Pešić Mirjana B
Institute of Food Technology and Biochemistry, Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Belgrade, Serbia.
Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, P.O. Box 23, 11010 Belgrade, Serbia.
Antioxidants (Basel). 2022 Oct 31;11(11):2164. doi: 10.3390/antiox11112164.
This study deals with the evaluation of the bioaccessibility and antioxidant properties of phenolic compounds from heat-treated skim goat-milk powder fortified with grape-pomace-seed extract, after in vitro gastrointestinal digestion. Ultra-high performance liquid chromatography coupled to diode array detection and mass spectrometry (UHPLC-DAD MS/MS) analysis confirmed the abundant presence of phenolic acids and flavan-3-ols in the grape-pomace-seed extract (SE) and heat-treated skim goat-milk/seed-extract powder (TME). After in vitro digestion of TME powder and recovery of total quantified phenolics, flavan-3-ols and phenolic acids were 18.11%, 24.54%, and 1.17%, respectively. Low recovery of grape-pomace-seed phenolics indicated strong milk protein-phenolic interactions. Electrophoretic analysis of a soluble fraction of digested heat-treated skim goat milk (TM) and TME samples showed the absence of bands originating from milk proteins, indicating their hydrolysis during in vitro gastrointestinal digestion. The digested TME sample had better antioxidant properties in comparison to the digested TM sample (except for the ferrous ion-chelating capacity, FCC), due to the presence of bioaccessible phenolics. Taking into account the contribution of the digestive cocktail, digested TME sample had lower values of total phenolic content (TPC), in vitro phosphomolybdenum reducing capacity (TAC) and ferric reducing power (FRP), compared to the undigested TME sample. These results could be attributed to low recovery of phenolic compounds. TME powder could be a good carrier of phenolics to the colon; thus, TME powder could be a promising ingredient in the formulation of functional food.
本研究探讨了体外胃肠道消化后，添加葡萄皮籽提取物的热处理脱脂山羊奶粉中酚类化合物的生物可及性和抗氧化特性。超高效液相色谱-二极管阵列检测-质谱联用（UHPLC-DAD MS/MS）分析证实，葡萄皮籽提取物（SE）和热处理脱脂山羊奶/籽提取物粉（TME）中富含酚酸和黄烷-3-醇。TME粉体外消化并回收总定量酚类物质后，黄烷-3-醇和酚酸的回收率分别为18.11%、24.54%和1.17%。葡萄皮籽酚类物质回收率低表明牛奶蛋白与酚类物质之间存在强烈的相互作用。对消化后的热处理脱脂山羊奶（TM）和TME样品的可溶部分进行电泳分析，结果显示没有源自牛奶蛋白的条带，表明它们在体外胃肠道消化过程中发生了水解。由于存在生物可及性酚类物质，与消化后的TM样品（除亚铁离子螯合能力FCC外）相比，消化后的TME样品具有更好的抗氧化性能。考虑到消化液的作用，与未消化的TME样品相比，消化后的TME样品的总酚含量（TPC）、体外磷钼酸还原能力（TAC）和铁还原能力（FRP）值较低。这些结果可能归因于酚类化合物的回收率低。TME粉可能是酚类物质进入结肠的良好载体；因此，TME粉可能是功能性食品配方中有前景的成分。
