Enzymatic formation of galactooligosaccharides in goat milk
Enzymatic formation of galactooligosaccharides in goat milk
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羊奶中低聚半乳糖的酶促形成
DOI：
10.1016/j.fbio.2018.09.005
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发表时间：
2018
期刊：
影响因子：
5.2
通讯作者：
Y. Hemar
中科院分区：
文献类型：
--
作者：
F. Zhu;C. Prosser;Ying Zhu;D. Otter;Y. Hemar
羊奶因其诱人的营养成分而变得越来越受欢迎。低聚半乳糖 (GOS) 是具有健康益处的益生元。研究了使用两种商业 β-半乳糖苷酶（来自乳酸克鲁维酵母的 L6500 和来自米曲霉的 L10）在复原羊奶中酶促形成 GOS。使用高效阴离子交换色谱法对牛奶系统的碳水化合物组成进行定量。实验条件（45°C，pH 6.7）下β-半乳糖苷酶产生的主要GOS是6-半乳二糖、异乳糖和6-半乳糖基乳糖。当 L10 的乳糖转化率为 59%、L6500 的乳糖转化率为 88% 时，总固体量为 10% 的羊奶中 GOS 产量最高。进一步增加乳糖转化可减少 GOS 的形成。使用 L6500，将牛奶总固体浓度从 10% 增加到 30%（乳糖浓度从 47 克/升增加到 143 克/升），GOS 产量增加至总糖的 22%。由此可见，适宜的实验条件可用于在羊奶中生产具有益生元功能的GOS。
Goat milk has become more popular due to its attractive nutritional profile. Galactooligosaccharides (GOS) are prebiotics with health benefits. The enzymatic formation of GOS in reconstituted goat milk using two commercial β-galactosidases (L6500 from Kluyveromyces lactis and L10 from Aspergillus oryzae) was studied. The carbohydrate composition of the milk system was quantified using high-performance anion-exchange chromatography. Major GOS produced by β-galactosidases under the experimental conditions (45 °C, pH 6.7) were 6-galactobiose, allolactose, and 6-galactosyllactose. The maximum GOS yields in goat milk with 10% total solids were obtained when the lactose conversion rates were 59% for L10 and 88% for L6500. Further increasing lactose conversion decreased GOS formation. Increasing milk concentration from 10% to 30% total solids (lactose concentration from 47 to 143 g/L) increased GOS yields up to 22% of the total sugars using L6500. It may be concluded that suitable experimental conditions can be used to produce GOS in goat milk with prebiotic function.