Hamad Samar, Chen Run, Zhou Zhitong, Nasr Pedram, Li Ye Ling, Rafiee Tari Niloufar, Rogers Michael A, Wright Amanda J
Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada.
Department of Food Science, University of Guelph, Guelph, ON, Canada.
Front Nutr. 2022 Jul 22;9:940045. doi: 10.3389/fnut.2022.940045. eCollection 2022.
It is poorly understood how the physical state of emulsified triacylglycerol (TAG) alters colloidal behavior in the gastrointestinal tract to modulate lipid digestion and absorption. We, therefore, aimed to investigate the individual and combined effects on fatty acid (FA) bioaccessibility using the dynamic TIM-1 digestion model and integrate the results with those from a human clinical study. Four 20% oil-in-water emulsions with overlapping particle size distributions contained either partially crystalline solid (palm stearin) or liquid (palm olein) lipid droplets at 37°C and either the colloidally acid-stable Tween 80 (2.2%) or acid-unstable Span 60 (2.5%) emulsifier. Experimental meals were fed to the TIM-1, and jejunal and ileal dialysates were analyzed over 6 h to measure free FA concentration. Cumulative FA bioaccessibility was significantly higher for the liquid stable emulsion compared to all others ( < 0.05), which did not differ ( > 0.05). Emulsified TAG physical state was associated with differences in overall bioaccessibility (higher for liquid state TAG) in the colloidally stable emulsions, but this difference was blunted in droplets susceptible to acidic flocculation. In contrast, human postprandial TAG concentrations did not differ significantly between the emulsions. The discrepancy may relate to differences in gastric emptying (GE) as evidenced by ultrasonography. When the differences in GE were accounted for in follow-up TIM-1 experiments, the findings aligned more closely. Cumulative FA bioaccessibility for the liquid stable emulsion no longer differed significantly from the other emulsions, and SU's bioaccessibility was the lowest, consistent with the observations. This work highlights the potential for TAG physical state and colloidal stability to interactively alter behavior in the gastrointestinal tract with implications for FA absorption, and the importance of establishing and improving correlations in food-nutrition research.
目前人们对乳化三酰甘油（TAG）的物理状态如何改变胃肠道中的胶体行为以调节脂质消化和吸收了解甚少。因此，我们旨在使用动态TIM-1消化模型研究其对脂肪酸（FA）生物可及性的单独和综合影响，并将结果与一项人体临床研究的结果相结合。四种具有重叠粒径分布的20%水包油乳液在37°C下含有部分结晶固体（棕榈硬脂）或液体（棕榈油）脂滴，以及胶体酸稳定的吐温80（2.2%）或酸不稳定的司盘60（2.5%）乳化剂。将实验餐喂给TIM-1，并在6小时内分析空肠和回肠透析液以测量游离脂肪酸浓度。与所有其他乳液相比，液体稳定乳液的累积FA生物可及性显著更高（<0.05），其他乳液之间无差异（>0.05）。在胶体稳定的乳液中，乳化TAG的物理状态与整体生物可及性的差异有关（液态TAG更高），但这种差异在易受酸性絮凝影响的液滴中减弱。相比之下，各乳液之间人体餐后TAG浓度无显著差异。这种差异可能与超声检查所显示的胃排空（GE）差异有关。当在后续的TIM-1实验中考虑GE的差异时，研究结果更趋于一致。液体稳定乳液的累积FA生物可及性与其他乳液不再有显著差异，而SU的生物可及性最低，与观察结果一致。这项工作强调了TAG物理状态和胶体稳定性可能相互作用改变胃肠道行为从而影响FA吸收的可能性，以及在食品营养研究中建立和改善相关性的重要性。
