Abstract：
Alternative milk products such as A2 milk are gaining popular stand within consumer market, for their healthy profile and expected greater digestibility characteristics. However, total mineral content and its bioaccessible profile have lacked in studies through the years, even more because of their relevance in public health. The present study aimed to evaluate the mineral profile of commercial A2 bovine milk (AT) and estimate the bioaccessibility of calcium, phosphorus and magnesium using the INFOGEST protocol. Non-A2 samples (NAT) were evaluated for comparison purpose. The determination of Ca, Mg, Na and K was performed by FAAS and total P was quantified by colorimetric method. Total protein content was determined by Kjeldahl method. Free amino acids were quantified by OPA method along the in vitro digestion stages. Total content of Ca, Na and P exhibited equivalent results between samples, although A2 milk showed elevated levels of total Mg and K in the analyzed batches. AT showed protein content equivalent to NAT. In addition, levels of free NH2 were observed 2 times higher in AT, during the first hour of pancreatic phase in the intestinal digestion. Bioaccessibility of Ca showed equivalent percentages for AT (12-42 %) and NAT (10-39 %). The observed low values were possibly derived from interferences with saturated fatty acids and standardized electrolytes during digestion. Similar amounts of bioaccessible Mg were found for all milk samples (35-97 %), while A2 samples evidenced percentages of bioaccessible P exceeding 60 % across the three batches. Despite the health benefits associated to A2 milk, the study did not evidence clear distinction from non-A2 milk in terms of enhanced essential mineral solubility in digestive tract simulation, considering the association of greater digestibility expected for A2 milk.
摘要：
替代奶制品，如A2牛奶在消费市场中获得了广泛的地位，因为它们的健康特征和预期的更高的消化率特征。然而,多年来的研究中缺乏总矿物质含量及其生物可及性特征，更重要的是，它们与公共卫生有关。本研究旨在评估商业A2牛乳（AT）的矿物质分布并估计钙的生物可及性，磷和镁使用INFOGEST协议。为了比较目的,评价非A2样品(NAT)。Ca的测定,Mg,Na和K通过FAAS进行，总P通过比色法定量。用Kjeldahl法测定总蛋白含量。在体外消化阶段通过OPA方法定量游离氨基酸。Ca总含量,Na和P在样品之间表现出相等的结果，尽管A2牛奶在分析的批次中显示出升高的总Mg和K水平。AT显示蛋白质含量相当于NAT。此外,在AT中观察到游离NH2的水平高2倍，在肠道消化的第一个小时胰腺阶段。对于AT（12-42％）和NAT（10-39％），Ca的生物可及性显示出相等的百分比。观察到的低值可能来自消化过程中对饱和脂肪酸和标准化电解质的干扰。在所有牛奶样品中发现了相似量的生物可利用的Mg（35-97％），而A2样品证明在三个批次中生物可利用P的百分比超过60%。尽管与A2牛奶相关的健康益处，该研究没有证据表明与非A2牛奶在消化道模拟中增加的必需矿物质溶解度方面有明显区别，考虑到A2牛奶预期的更高消化率的关联。
