Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 PB Wageningen, The Netherlands.
Food Quality and Design group, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
Food Funct. 2024 Mar 18;15(6):3098-3107. doi: 10.1039/d3fo04063a.
: studies suggest that casein coagulation of milk is influenced by its mineral composition, and may therefore affect the dynamics of protein digestion, gastric emptying and appearance of amino acids (AA) in the blood, but this remains to be confirmed . : This study aimed to compare gastrointestinal digestion between two milks with the same total calcium content but different casein mineralization (CM). : Fifteen males (age 30.9 ± 13.8 years, BMI 22.5 ± 2.2 kg m) participated in this randomized cross-over study with two treatments. Participants underwent gastric magnetic resonance imaging (MRI) scans at the baseline and every 10 min up to 90 min after consumption of 600 ml milk with low or high CM. Blood samples were taken at the baseline and up to 5 hours postprandially. Primary outcomes were postprandial plasma AA concentrations and gastric emptying rate. Secondary outcomes were postprandial glucose and insulin levels, gastric coagulation as estimated by image texture metrics, and appetite ratings. : Gastric content volume over time was similar for both treatments. However, gastric content image analysis suggested that the liquid fraction emptied quicker in the high CM milk, while the coagulum emptied slower. Relative to high CM, low CM showed earlier appearance of AAs that are more dominant in casein, such as proline (MD 4.18 μmol L, 95% CI [2.38-5.98], < 0.001), while there was no difference in appearance of AAs that are more dominant in whey protein, such as leucine. The image texture metrics homogeneity and busyness differed significantly between treatments (MD 0.007, 95% CI [0.001, 0.012], = 0.022; MD 0.005, 95% CI [0.001, 0.010], = 0.012) likely because of a reduced coagulation in the low CM milk. : Mineral composition of milk can influence postprandial serum AA kinetics, likely due to differences in coagulation dynamics. The clinical trial registry number is NL8959 (https://clinicaltrials.gov).
研究表明，牛奶中的酪蛋白凝结受其矿物质组成的影响，因此可能会影响蛋白质消化、胃排空和血液中氨基酸（AA）的出现，但这仍有待证实。本研究旨在比较两种总钙含量相同但酪蛋白矿化程度（CM）不同的牛奶的胃肠道消化情况。15 名男性（年龄 30.9 ± 13.8 岁，BMI 22.5 ± 2.2 kg/m2）参与了这项随机交叉研究，接受了两种处理。参与者在摄入低或高 CM 牛奶 600 毫升后，每隔 10 分钟进行一次胃磁共振成像（MRI）扫描，直到 90 分钟。在基线和餐后 5 小时内采集血样。主要结局是餐后血浆 AA 浓度和胃排空率。次要结局是餐后血糖和胰岛素水平、通过图像纹理度量估计的胃凝结以及食欲评分。两种处理的胃内容物随时间的体积相似。然而，胃内容物图像分析表明，高 CM 牛奶中的液体部分排空更快，而凝结物排空更慢。与高 CM 相比，低 CM 显示出更早出现更受酪蛋白支配的 AA，如脯氨酸（MD 4.18 μmol/L，95%CI[2.38-5.98]， < 0.001），而在更受乳清蛋白支配的 AA 出现方面没有差异，如亮氨酸。两种处理之间的图像纹理度量均匀性和忙碌度差异显著（MD 0.007，95%CI[0.001，0.012]， = 0.022；MD 0.005，95%CI[0.001，0.010]， = 0.012），可能是因为低 CM 牛奶中的凝结减少了。牛奶的矿物质组成会影响餐后血清 AA 动力学，可能是由于凝结动力学的差异。临床试验注册号为 NL8959（https://clinicaltrials.gov）。
