The effect of the addition of galactooligosaccharides (GOS) on sterol bioaccessibility in three plant sterol (PS)-enriched milk-based fruit beverages (without GOS addition (MfB) and with 2.5 g (MfB-G₂) and 5.0 g (MfB-G₅) GOS per 250 mL) was evaluated after micellar gastrointestinal digestion. Cholesterol bioaccessibility was very similar among beverages, though a slight significant increase (from 80% to 85%) was observed by the addition of 5.0 g GOS. The addition of GOS did not affect total PS bioaccessibility (≈37%). Based on the results obtained after micellar digestion, it has been demonstrated that these beverages could be a suitable food matrix for simultaneous enrichment with PS and GOS. The harmonized in vitro digestion model INFOGEST was applied to the MfB beverage, but the cholesterol content could not be quantified due to its contribution of bile salts. Hence, it was proposed: (i) a change in porcine bile salt concentration from 10 mM to 1.4 mM (in order to compare with micellar digestion); or (ii) a change of bile salt origin (bovine instead of porcine), maintaining physiological concentration (10 mM, INFOGEST condition). Both options allowed cholesterol quantification, with bioaccessibilities of 62% (reduction of bile salts) and 38% (replacement of the bile salt source), whereas plant sterol bioaccessibilities were 22% and 14%, respectively. Therefore, the change of bile salt origin maintaining INFOGEST concentration is proposed as a method to evaluate sterol (cholesterol and PS) bioaccessibility in these beverages, demonstrating the need for the selection of appropriate conditions of the INFOGEST harmonized method according to the food matrix and compounds to be determined.

中文翻译：

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低聚半乳糖对富含植物固醇的饮料中固醇的生物可及性的影响：INFOGEST统一消化方法的适应

在三种富含植物固醇（PS）的牛奶基果汁饮料中添加低聚半乳糖（GOS）对固醇生物可及性的影响（不添加GOS（MfB）以及添加2.5 g（MfB-G ₂）和5.0 g（MfB-胶束胃肠消化后，评估G ₅）（每250 mL GOS）。饮料之间的胆固醇生物利用度非常相似，尽管通过添加5.0 g GOS可以观察到胆固醇的轻微增加（从80％增至85％）。添加GOS不会影响总PS生物可及性（约37％）。根据胶束消化后获得的结果，已证明这些饮料可能是同时富含PS和GOS的合适食品基质。体外协调消化模型INFOGEST被应用于MfB饮料，但是由于胆汁盐的贡献，无法对胆固醇含量进行定量。因此，建议：（i）将猪胆汁盐浓度从10 mM改变为1.4 mM（以便与胶束消化比较）；或（ii）改变胆汁盐的来源​​（用牛代替猪），保持生理浓度（10 mM，INFOGEST条件）。两种选择均允许对胆固醇进行定量，其生物利​​用度分别为62％（减少胆汁盐）和38％（代替胆汁盐源），而植物固醇的生物利用度分别为22％和14％。因此，建议将维持INFOGEST浓度的胆汁盐来源的变化作为评估这些饮料中固醇（胆固醇和PS）生物利用度的方法，