The food additive carrageenan (E407) (CGN) is a family of sulphated galactans widely used in numerous processed foods, including dairy. There are various indications that CGN may hinder digestive proteolysis. This study sought to link CGN macromolecular characteristics to its implications on digestive proteolysis of whey protein isolate (WPI) in toddlers, adults and seniors. Size exclusion chromatography and dynamic laser scattering reveal commercial CGN samples differ in molecular weight distributions, zeta-potentials and flow behavior of WPI-CGN mixtures. Moreover, κ-CGN, ι-CGN and λ-CGN were found to contain low MW (<200kDa) fractions at levels of 6.36±2.11% (w/w), 3.64±1.06% (w/w) and 2.08±1.41% (w/w), respectively. In vitro human digestion of WPI-CGN mixtures and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of digesta indicate that CGN alters the breakdown of alpha-lactalbumin, beta-lactoglobulin and lactoferrin differentially in toddlers, adults and seniors digestion conditions. Interestingly, proteomic analyses indicate there is a possible correlation between CGN degree of sulphation and the release of bioactive peptide homologues in the gut lumen. Moreover, these analyses indicate CGN compromises the bioaccessibility of essential amino acids. Altogether, this study shows CGN may attenuate whey digestive proteolysis. This effect should be taken in account by food manufacturers and regulatory agencies in view of the rising levels of exposure to CGN in the human diet.

食品添加剂卡拉胶（E407）（CGN）是一族硫酸半乳聚糖，广泛用于包括乳制品在内的多种加工食品中。有各种迹象表明，CGN可能会阻碍消化蛋白水解。这项研究试图将CGN大分子特征与其对幼儿，成人和老年人的乳清蛋白分离物（WPI）的消化蛋白水解的影响联系起来。尺寸排阻色谱和动态激光散射揭示了商用CGN样品在WPI-CGN混合物的分子量分布，ζ电位和流动行为方面存在差异。此外，发现κ-CGN，ι-CGN和λ-CGN包含低MW（<200kDa）分数，含量分别为6.36±2.11％（w / w），3.64±1.06％（w / w）和2.08±1.41 ％（w / w）分别。体外人体对WPI-CGN混合物的消化和十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）分析表明，CGN在幼儿，成人和老年人的消化条件下会不同程度地改变α-乳白蛋白，β-乳球蛋白和乳铁蛋白的分解。有趣的是，蛋白质组学分析表明，CGN的硫酸化程度与肠腔中生物活性肽同源物的释放之间可能存在相关性。此外，这些分析表明CGN损害了必需氨基酸的生物可及性。总而言之，这项研究表明CGN可能会减弱乳清消化蛋白水解作用。鉴于人类饮食中CGN暴露水平的上升，食品制造商和监管机构应考虑到这种影响。