Seasonal variation in the positional distribution of fatty acids in bovine milk fat (Supplementary Tables)

In this study, the variation in the regiospecific distribution of fatty acids (FA) of bovine milk fat throughout a year has been studied. The milk fat samples were collected on a weekly basis from May 2017 till April 2018 in the Netherlands as representative of the average bovine milk fat composition. The weekly samples were combined into months and the monthly FA compositions at the sn-2 and sn-1(3) positions were determined via enzymatic transesterification with Candida antarctica lipase B. The regiospecific distribution of FA were assessed by using intra- and interpositional approaches. Based on the intrapositional approach, majority of the sn-2 and sn-1(3) FA showed significant seasonal variation. In summer, the concentrations of blood derived FA (i.e. C18:0, C18:1 cis-9) increased and novo synthesized FA decreased. Highest concentrations of C16:0 was observed in sn-2 position of milk fat in winter whereas in summer unsaturated FA were highest at this position. Interestingly, according to interpositional distribution the esterification preferences of FA either sn-2 or sn-1(3) positions did not change significantly upon seasonal variation. The supplementary files reported in this depository are part of the manuscript by Yener et al., 2021 in Journal of Dairy Science entitled "Seasonal variation in the positional distribution of fatty acids in bovine milk fat". and can be described as below: -Supplementary Table 1 (Comparisons of the fatty acid (FA) concentrations (mol %) at the sn-2 and sn-1(3) positions in the triacylglycerol structures of bovine milk fat between seasons) -Supplementary Table 2 (Statistical analysis on the stereolocation preferences between the interpositional distribution (%) and the hypothetical proportions at the sn-2 (33.3%) and sn-1(3) (66.7%) positions in the triacylglycerol (TAG) structures) -Supplementary Table 3 (Fatty acid composition (mol %) and fat content of bovine milk fat)

本研究围绕牛乳脂肪中脂肪酸 (Fatty Acids, FA) 的区域特异性分布全年变化展开探究。研究于2017年5月至2018年4月期间在荷兰每周采集牛乳脂肪样本，以代表常规牛乳脂肪的组成特征。将每周采集的样本合并为月度样本，并通过南极假丝酵母脂肪酶B催化的酶促酯交换反应，测定月度样本在sn-2与sn-1(3)位点的脂肪酸组成。研究通过位点内分析法与位间分析法，对脂肪酸的区域特异性分布进行评估。基于位点内分析法结果，多数sn-2与sn-1(3)位点的脂肪酸均呈现出显著的季节性变化：夏季时，血液来源脂肪酸（即C18:0、C18:1顺式-9）的浓度升高，而从头合成脂肪酸的浓度则有所下降；冬季时，牛乳脂肪sn-2位点的C16:0浓度达到峰值，而夏季时该位点的不饱和脂肪酸浓度最高。值得注意的是，基于位间分布分析结果，脂肪酸在sn-2或sn-1(3)位点的酯化偏好性并未随季节变化出现显著改变。本数据集仓储中收录的补充文件，系Yener等人2021年发表于《乳业科学杂志》（*Journal of Dairy Science*）的论文《牛乳脂肪中脂肪酸位点分布的季节性变化》的配套材料，具体如下：
- 补充表1：不同季节牛乳脂肪甘油三酯 (Triacylglycerol, TAG) 结构中sn-2与sn-1(3)位点的脂肪酸浓度（摩尔百分比）对比
- 补充表2：甘油三酯结构中sn-2位点（理论占比33.3%）与sn-1(3)位点（理论占比66.7%）的位间分布（百分比）与立体定位偏好性的统计学分析
- 补充表3：牛乳脂肪的脂肪酸组成（摩尔百分比）与脂肪含量

搜集汇总

背景与挑战

背景概述

该数据集提供了牛乳脂肪中脂肪酸位置分布季节性变化的补充表格，基于2017-2018年荷兰每周采集的样本，分析sn-2和sn-1(3)位置的脂肪酸组成。研究发现，多数脂肪酸在sn-2和sn-1(3)位置呈现显著季节性变化，但脂肪酸的酯化位置偏好未因季节变化而显著改变，数据集包含三个Excel表格，支持脂质和乳制品化学研究。