Abstract Bigels based on κ-carrageenan hydrogel and monoglyceride oleogels were developed as carriers for lipophilic bioactives. Bigels were prepared by mixing the hydrogel and oleogels under temperature control, and the roles of oleogel fraction in the structures of the bigels and the delivery of β-carotene were investigated. Microstructural observation indicated that the structures of bigels changed from oleogel-in-hydrogel type (25, 40, 50%) to bi-continuous type (60%) and to hydrogel-in-oleogel type (75%). Mechanical properties (storage modulus, stiffness, fracture stress) of the bigels were enhanced with higher content of oleogel, and the biggest enhancement was observed when the bigel was transformed into bi-continuous or hydrogel-in-oleogel structures. XRD analysis revealed the crystalline structures of monoglyceride and liquid state of the corn oil, and the highest crystallinity was found in the bigel with 50% oleogel. Thermal stability of the bigels was improved with the increase in oleogel fraction, as monoglyceride tended to melt at higher temperature with higher oleogel content. All the bigels had low swelling ratio except for the sample with 50% oleogel. When bigels were used to encapsulate β-carotene, oleogel fraction also influenced stability and in vitro gastrointestinal release of the bioactive. Both light stability and thermal stability of β-carotene were improved with the increase in oleogel fraction, and about 70% of the original β-carotene could be retained after 8 h of UV-light exposure in the bigel with 75% oleogel. All the bigels had minor release in simulated gastric juice, and the release ratios were greatly increased in the simulated intestinal juice, and higher content of oleogel could promote the release.

中文翻译：

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基于κ-角叉菜胶水凝胶和甘油单酯油凝胶作为β-胡萝卜素载体的食品级大凝胶的开发：油凝胶部分的作用

摘要 基于κ-角叉菜胶水凝胶和甘油单酯油凝胶的Bigels 被开发为亲脂性生物活性物质的载体。通过在温度控制下混合水凝胶和油凝胶制备 Bigels，并研究了油凝胶组分在 Biggel 结构和 β-胡萝卜素递送中的作用。微观结构观察表明，双凝胶的结构从油凝胶-水凝胶型（25%、40%、50%）变为双连续型（60%）和油凝胶-水凝胶型（75%）。Bigel 的机械性能（储能模量、刚度、断裂应力）随着油凝胶含量的增加而增强，当 Bigel 转变为双连续或油凝胶中的水凝胶结构时，观察到最大的增强。XRD分析揭示了玉米油的甘油单酯和液态的晶体结构，其中在含50%油凝胶的bigel中发现了最高的结晶度。bigels 的热稳定性随着油凝胶分数的增加而提高，因为单酸甘油酯倾向于在更高的温度下随着油凝胶含量的增加而熔化。除了含有 50% 油凝胶的样品外，所有 Biggel 的溶胀率都较低。当使用 bigels 封装 β-胡萝卜素时，油凝胶部分也会影响生物活性物质的稳定性和体外胃肠道释放。β-胡萝卜素的光稳定性和热稳定性都随着油凝胶分数的增加而提高，在含有 75% 油凝胶的 bigel 中，在紫外光照射 8 小时后可以保留约 70% 的原始 β-胡萝卜素。所有的bigels在模拟胃液中都有轻微的释放，