Calcium Alters the Interfacial Organization of Hydrolyzed Lipids during Intestinal Digestion.
Calcium Alters the Interfacial Organization of Hydrolyzed Lipids during Intestinal Digestion.
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DOI：
10.1021/acs.langmuir.8b00841
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发表时间：
2018-06
期刊：
影响因子：
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通讯作者：
A. Torcello-Gómez;C. Boudard;A. Mackie
中科院分区：
文献类型：
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作者：
A. Torcello-Gómez;C. Boudard;A. Mackie
钙在脂质消化中起着重要的双重作用：通过形成不溶性钙皂促进长链脂肪酸从油水界面去除，同时也限制了它们的生物可及性。这在含钙浓度高的食物中更为明显，如乳制品。然而，很少有人关注钙对脂质消化过程中界面性质的影响，尽管这主要是一个界面反应。本研究的重点是在没有和存在两种主要的人胆汁盐（糖胆酸钠或糖鹅脱氧胆酸钠）的情况下，胰腺脂肪酶在油脂分解过程中油水界面形成钙皂的动力学。脂肪酶、胆汁盐和脂解产物的竞争性吸附，以及在钙浓度增加的情况下钙皂的形成，主要是通过记录界面张力和原位膨胀模量来表征的。在没有胆盐的情况下，随着时间的推移，钙与脂肪酸在油水界面处形成相对较强的钙皂粘弹性网络。钙皂网的膨胀模量与脂解产物的界面浓度和钙体积浓度有直接关系。钙皂也可以在浸入模拟肠道水相的油滴表面形成连续的粗糙层。尽管胆盐具有不同的表面活性，但它们在与脂肪酶和脂解产物的界面竞争中发挥相似的作用，尽管改变了它们的动力学。胆汁盐的存在破坏了钙皂的网络，正如膨胀模量的降低和在油滴表面形成钙皂岛所表明的那样。钙对脂肪分解的促进作用可能是由于脂肪酸络合和随后从界面上去除，而不是减少了脂肪酶和胆盐分子之间的静电排斥，促进了脂肪酶的吸附。这里显示的工作对在钙存在下的油溶性生物活性的传递有影响。
Calcium plays an important dual role in lipid digestion: promoting removal of long-chain fatty acids from the oil-water interface by forming insoluble calcium soaps while also limiting their bioaccessibility. This becomes more significant in food containing high calcium concentration, such as dairy products. Nevertheless, scarce attention has been paid to the effect of calcium on the interfacial properties during lipid digestion, despite this being largely an interfacial reaction. This study focused on the dynamics of the formation of calcium soaps at the oil-water interface during lipolysis by pancreatic lipase in the absence and presence of the two primary human bile salts (sodium glycocholate or sodium glycochenodeoxycholate). The competitive adsorption of lipase, bile salts, and lipolysis products, as well as the formation of calcium soaps in the presence of increasing concentrations of calcium were mainly characterized by recording the interfacial tension and dilatational modulus in situ. In the absence of bile salts, calcium complexes with fatty acids at the oil-water interface forming a relatively strong viscoelastic network of calcium soaps over time. The dilatational modulus of the calcium soap network is directly related to the interfacial concentration of lipolysis products and the calcium bulk concentration. Calcium soaps are also visualized forming a continuous rough layer on the surface of oil droplets immersed in simulated intestinal aqueous phase. Despite bile salts having different surface activity, they play a similar role on the interfacial competition with lipase and lipolysis products although altering their kinetics. The presence of bile salts disrupts the network of calcium soaps, as suggested by the decrease in the dilatational modulus and the formation of calcium soap islands on the surface of the oil droplets. The accelerant effect of calcium on lipolysis is probably because of fatty acid complexation and subsequent removal from the interface rather than reduced electrostatic repulsion between lipase and bile salt molecules and promoted lipase adsorption. The work shown here has implications for the delivery of oil-soluble bioactives in the presence of calcium.