Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Università di Udine, via Sondrio 2/a, 33100 Udine, Italy.
Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Università di Udine, via Sondrio 2/a, 33100 Udine, Italy; Istituto di Cristallografia, Consiglio Nazionale delle Ricerche, 34100 Trieste, Italy.
Food Res Int. 2018 Mar;105:599-604. doi: 10.1016/j.foodres.2017.11.062. Epub 2017 Nov 26.
The aim of this research was to study β-carotene degradation kinetics into lipid systems containing different fat crystal networks in the presence of increasing liquid oil amounts. To this purpose, fat blends containing liquid saturated medium chain triacylglycerols (MCT) with increasing content of saturated monoglycerides (MG), tripalmitin (PPP) and tristearin (SSS) were added with 0.6mg/g β-carotene. The fat crystal networks formed in the fat blends were characterized by using polarized light microscopy and synchrotron X-ray diffraction (XRD). In addition, β-carotene degradation was monitored during storage in the dark at 20°C. Results highlighted that fat crystallization could differently affect β-carotene stability. In bulk SSS and PPP, β-carotene degradation proceeded at comparable rate, whereas when the saturated liquid oil MCT is included in the fat network, the rate of oxidation slightly decreased. Interestingly, the oxidation rate was not significantly affected by the solid/liquid ratio of the systems. A completely different behavior was observed in MG containing systems: the rate of β-carotene oxidation was in every case significantly lower than that observed in SSS and PPP containing samples. Also in this case, the MG protective effect was independent on its content in the fat mixtures.
本研究旨在研究β-胡萝卜素在含有不同脂肪晶体网络的脂质体系中的降解动力学，同时考察随着液体油含量的增加所产生的影响。为此，向含有液体饱和中链三酰基甘油（MCT）且其饱和单甘油脂（MG）、三棕榈酸甘油酯（PPP）和三硬脂酸甘油酯（SSS）含量逐渐增加的脂肪混合物中添加 0.6mg/g 的β-胡萝卜素。采用偏光显微镜和同步加速器 X 射线衍射（XRD）对脂肪混合物中形成的脂肪晶体网络进行了表征。此外，还在 20°C 避光条件下储存过程中监测了β-胡萝卜素的降解情况。结果表明，脂肪结晶会对β-胡萝卜素的稳定性产生不同的影响。在块状的 SSS 和 PPP 中，β-胡萝卜素的降解速度相当，而当饱和液体油 MCT 包含在脂肪网络中时，氧化速度略有下降。有趣的是，氧化速率不受体系固液比的显著影响。在含有 MG 的体系中观察到完全不同的行为：β-胡萝卜素氧化的速率在每种情况下均明显低于含有 SSS 和 PPP 的样品。在这种情况下，MG 的保护作用与其在脂肪混合物中的含量无关。
