Abstract The major reduction in probiotic viability that occurs during food storage and gastrointestinal transit limits their potential health benefits. Microencapsulation is one of the most effective methods to protect probiotics from various harsh conditions. In this study, a model probiotic (Pediococcus pentosaceus Li05) was encapsulated in an alginate-gelatin microgels in the absence and presence of magnesium oxide (MgO) nanoparticles (NPs). The morphology and surface properties of the encapsulation systems were characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM), which showed that both the probiotics and NPs were successfully incorporated into spherical microgels. The viability of the probiotic was evaluated after exposure to different conditions: long-term storage in an aerobic environment; heat treatment; and gastrointestinal transit. Encapsulation of the probiotics significantly enhanced their viability under these different conditions. Probiotics encapsulated in MgO-loaded microgels were more stable than free bacterial cells or those encapsulated in microgels alone: less than 2 log10 CFU reduction after 40 min incubation in gastric fluids versus 5 log10 CFU reduction in the first 10 min for free cells. The SEM images indicated that the NPs may lead to enhanced probiotic viability by filling pores inside the microgels, which may have inhibited the ability of oxygen and hydrogen ions to access the probiotics. Moreover, the MgO NPs neutralized the hydrogen ions in the gastric fluids, thereby reducing acid-induced degradation of the probiotics. These results demonstrate that MgO-loaded microgels may be a promising encapsulation and delivery system for improving the efficacy of orally administered probiotics by protecting them from the harsh conditions during storage and in the gastrointestinal tract.

中文翻译：

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通过封装在掺有无机纳米颗粒的微凝胶中增强益生菌（戊糖片球菌 Li05）的活力

摘要 在食品储存和胃肠道运输过程中，益生菌活力的大幅降低限制了它们潜在的健康益处。微胶囊化是保护益生菌免受各种恶劣条件影响的最有效方法之一。在这项研究中，在氧化镁 (MgO) 纳米粒子 (NPs) 不存在和存在的情况下，模型益生菌（戊糖片球菌 Li05）被封装在藻酸盐-明胶微凝胶中。封装系统的形态和表面性质通过透射电子显微镜 (TEM) 和原子力显微镜 (AFM) 进行表征，这表明益生菌和纳米颗粒都成功地结合到球形微凝胶中。在暴露于不同条件后评估益生菌的生存能力：在有氧环境中长期储存；热处理; 和胃肠道。益生菌的封装显着增强了它们在这些不同条件下的生存能力。封装在负载有 MgO 的微凝胶中的益生菌比游离细菌细胞或单独封装在微凝胶中的益生菌更稳定：在胃液中孵育 40 分钟后减少不到 2 log10 CFU，而游离细胞在前 10 分钟内减少 5 log10 CFU。SEM 图像表明，纳米颗粒可能通过填充微凝胶内部的孔来增强益生菌的活力，这可能抑制了氧和氢离子进入益生菌的能力。此外，MgO NPs 中和了胃液中的氢离子，从而减少了酸诱导的益生菌降解。