Thermal-induced-stable high internal phase emulsion for lycopene encapsulation and delivery: Pre-heat treatment mediated facilitation on the isomerization, stabilization, and release of lycopene
Hai Chen, Yi Sun, Xin Feng, Liang Ma, Hongjie Dai, Hongxia Wang, Hankun Zhu, Yong Yu, Yuhao Zhang
Abstract
Lycopene possesses many beneficial physiological effects, especially the Z-isomer, but the hydrophobic property, poor stability, lower percentage of Z-isomer and bioaccessibility highly limited its practical applications. Herein, the purpose of this study is to provide an alternative delivery system for lycopene isomerization and delivery by using thermal-induced-stable high internal phase emulsion (TIS-HIPE). The results shows that encapsulation of lycopene in TIS-HIPE significantly improved its storage stability, and pre-heat treatment on the lycopene-loaded TIS-HIPE can enhance the protective effect of lycopene against temperature and UV exposures. After storage at 40 °C for 14 days, the retention rate of lycopene increased from 40% to 86%. More importantly, pre-heat treatment promoted the conformational conversion of lycopene into more absorbable Z-isomers. Meanwhile, the protective effect of TIS-HIPE effectively inhibited the degradation of converted Z-isomers during storage. Besides, the pre-heated TIS-HIPE is more stable in the gastrointestinal tract and is more prone to form micelle phase. Moreover, as compared to lycopene in oil, the bioaccessibility in TIS-HIPE increased almost 2 times, and pre-heat treatment can further improve its bioaccessibility. Therefore, the TIS-HIPE could serve as excellent vehicles for lycopene delivery, and pre-heat treatment can facilitate the stability improvement, Z-isomerization, release and absorption of lycopene.