Agriculture and Agri-Food Canada, Saint-Hyacinthe Research and Development Centre, Saint-Hyacinthe, QC J2S 8E3, Canada; Department of Food Science and Agricultural Chemistry, Macdonald Campus, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada.
Agriculture and Agri-Food Canada, Saint-Hyacinthe Research and Development Centre, Saint-Hyacinthe, QC J2S 8E3, Canada.
Food Res Int. 2024 Feb;178:113932. doi: 10.1016/j.foodres.2024.113932. Epub 2024 Jan 11.
The Digestible Indispensable Amino Acid Score (DIAAS) is the new gold standard method for the assessment of protein nutritional quality. The DIAAS is evaluated with in vivo models, that are complex, constraining and costly. There is still no established method to assess it in vitro. In this study, we proposed to add a jejunal-ileal digestion phase to the standardized in vitro gastrointestinal digestion protocol developed by the International Network of Excellence on the Fate of Food in the Gastrointestinal Tract (INFOGEST protocol) to mimic brush border digestion and to enable DIAAS assessment in vitro in a more physiologically relevant manner. This jejunal-ileal digestion phase was performed with a porcine intestinal aminopeptidase as an alternative to brush border membrane extract, which is more difficult to obtain in a standardized way. This modified INFOGEST protocol was applied to various food matrices (faba bean, pea and soy flours, whey protein isolate and caseins) and the results were compared to published in vivo data to assess the model's physiological relevance. The addition of the jejunal-ileal digestion phase lead to a significant (p < 0.05) increase of 31 and 29 % in free and total amino acid digestibility, respectively, and of 83 % on average for the in vitro DIAAS values for all food matrices. Although the in vitro DIAAS remained underestimated compared to the in vivo ones, a strong correlation between them was observed (r = 0.879, p = 0.009), stating the relevance of this last digestion phase. This improved digestion protocol is proposed as a suitable alternative to evaluate the DIAAS in vitro when in vivo assays are not applicable.
可消化必需氨基酸评分（DIAAS）是评估蛋白质营养质量的新金标准方法。DIAAS 通过体内模型进行评估，这些模型复杂、受限且昂贵。目前还没有建立体外评估它的方法。在这项研究中，我们提出在标准化的体外胃肠道消化方案中添加空肠-回肠消化阶段，该方案由国际食品在胃肠道中命运卓越网络（INFOGEST 方案）开发，以模拟刷状缘消化，并以更符合生理的方式在体外评估 DIAAS。这个空肠-回肠消化阶段使用猪肠氨肽酶进行，替代了更难以标准化方式获得的刷状缘膜提取物。该改良 INFOGEST 方案应用于各种食物基质（羽扇豆、豌豆和大豆粉、乳清蛋白分离物和酪蛋白），并将结果与已发表的体内数据进行比较，以评估模型的生理相关性。添加空肠-回肠消化阶段导致游离和总氨基酸消化率分别显著增加（p<0.05）31%和 29%，所有食物基质的体外 DIAAS 值平均增加 83%。尽管与体内相比，体外 DIAAS 仍然被低估，但它们之间观察到很强的相关性（r=0.879，p=0.009），表明最后消化阶段的相关性。当体内试验不可用时，这种改良的消化方案被提议作为体外评估 DIAAS 的合适替代方法。
