INRAE, UR BIA, F-44316, Nantes, France.
Department of Food Technology and Engineering, School of Food Engineering, University of Campinas, 13083-862, Campinas, Brazil.
Food Funct. 2023 Dec 11;14(24):10868-10881. doi: 10.1039/d3fo03816e.
Investigating the gastrointestinal fate of food emulsions is critical to unveil their nutritional relevance. To this end, the protocol standardized by COST INFOGEST 2.0 is meaningful for guiding digestion experiments. In contrast with studies addressing emulsions with low dispersed phase volume fraction ( 0.05-0.1), we presently raise some points for a proper interpretation of the digestibility of emulsions with high lipid content using the pH-stat method. Oil-in-water high internal phase emulsions (HIPEs) were submitted to gastric pre-lipolysis with the addition of rabbit gastric lipase (RGE). Commercial mayonnaise ( 0.76) was systematically diluted ( 0.025, 0.05, 0.1, 0.15, 0.25, 0.4, and 0.76) to cover a wide range of enzyme-to-lipid ratios (8.5-0.3 U per µmol for RGE and 565.1-18.6 U per µmol for pancreatin, in the gastric and intestinal phases, respectively). Lipolysis was tracked either by fatty acid titration (NaOH titration) or completed by analysis of lipid classes and fatty acid composition. Gastric lipase resulted in substantial lipid hydrolysis, reaching 20 wt% at low lipid fractions ( 0.025 and 0.05). Likewise, the kinetics and extent of lipolysis during intestinal digestion were modulated by the enzyme-to-substrate ratio. A logarithmic relationship between lipid hydrolysis and lipid concentration was observed, with a very limited extent at the highest lipid content ( 0.76). A holistic interpretation relying on FFA titration and further evaluation of all lipolytic products appears of great relevance to capture the complexity of the effects involved. Overall, this work contributes to rationally and critically evaluating the outcomes of static experiments of lipid digestion.
研究食品乳液的胃肠道命运对于揭示其营养相关性至关重要。为此，COST INFOGEST 2.0 标准化的方案对于指导消化实验具有重要意义。与研究分散相体积分数较低（0.05-0.1）的乳液相比，我们目前提出了一些观点，以正确解释使用 pH -stat 法测定高脂质含量乳液的消化率。油包水高内相乳液（HIPE）用兔胃脂肪酶（RGE）进行胃前脂解。商业蛋黄酱（0.76）被系统稀释（0.025、0.05、0.1、0.15、0.25、0.4 和 0.76），以覆盖广泛的酶与脂质比（RGE 为 8.5-0.3 U/µmol，胰酶为 565.1-18.6 U/µmol，分别用于胃和肠阶段）。脂解通过脂肪酸滴定（NaOH 滴定）或通过分析脂质类和脂肪酸组成来跟踪。胃脂肪酶导致大量的脂质水解，在低脂质分数（0.025 和 0.05）下达到 20wt%。同样，在肠消化过程中，脂肪酶与底物比调节脂解的动力学和程度。观察到脂质水解与脂质浓度之间存在对数关系，在最高脂质含量（0.76）时，程度非常有限。依赖于 FFA 滴定和进一步评估所有脂解产物的整体解释似乎对于捕捉所涉及的复杂效应非常重要。总的来说，这项工作有助于合理和批判性地评估静态脂质消化实验的结果。
