School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Potenza, Viale dell'Ateneo Lucano 10-85100, Italy.
School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Potenza, Viale dell'Ateneo Lucano 10-85100, Italy.
J Dairy Sci. 2018 Sep;101(9):7691-7701. doi: 10.3168/jds.2018-14613. Epub 2018 Jun 28.
The aim of this work was to evaluate the phenolic compounds and antioxidant activity of goat milk yogurt characterized by different α-casein genotypes and fortified with Rhus coriaria leaf powder. The α-casein genotype was determined by isoelectric focusing, total phenol content was determined by the Folin-Ciocalteu method, phenolic compounds were identified and quantified by HPLC-UV analysis, and antioxidant activity was measured using 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing antioxidant power. The statistical analysis showed a significant effect of the studied factors. Comparing different genotypes it emerged that yogurt from goats with weak alleles at CSN1S1 loci (FF) showed the lowest phenolic compounds and therefore a lower antioxidant activity compared with yogurt from goats with strong alleles at CSN1S1 loci (AA, BB, AB). Rhus coriaria-fortified yogurt showed a significant increase in total phenolic compounds and antioxidant activity in comparison with plain yogurt. The FF-fortified yogurt presented the lowest total phenol content and antioxidant activity. This could be due to a greater capacity of proteins and peptides in this yogurt to form stable complexes with phenols. The different total phenol content detected in R. coriaria-fortified yogurt indicates that the α-casein genotype influenced the amount of added phenols that are bound to the caseins and, therefore, the part that remains free and that affects the biological capacity of the final product.
本研究旨在评估不同α-酪蛋白基因型的羊奶酸奶的酚类化合物和抗氧化活性，并对其进行强化，添加鼠李叶粉。α-酪蛋白基因型通过等电聚焦法确定，总酚含量通过福林-肖卡法测定，采用高效液相色谱-紫外分析鉴定和定量酚类化合物，使用 2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸和铁还原抗氧化能力法测定抗氧化活性。统计分析显示研究因素有显著影响。比较不同基因型发现，CSN1S1 基因座弱等位基因（FF）的羊奶酸奶的酚类化合物含量最低，因此抗氧化活性也低于 CSN1S1 基因座强等位基因（AA、BB、AB）的羊奶酸奶。与普通酸奶相比，添加鼠李叶粉的酸奶总酚含量和抗氧化活性显著增加。与普通酸奶相比，FF 强化酸奶的总酚含量和抗氧化活性最低。这可能是由于这种酸奶中的蛋白质和肽具有更大的能力与酚类形成稳定的复合物。添加鼠李叶粉的酸奶中检测到的不同总酚含量表明，α-酪蛋白基因型影响与酪蛋白结合的添加酚类的数量，因此影响游离部分和最终产品的生物学能力。
