To obtain natural protein gels as delivery systems loading with probiotics and protect the probiotics from heat treatment, we fabricated casein-based gels using micellar casein concentrates (MCC) via microfiltration and then embedded with Lactobacillus Rhamnosus GG (LGG). Rheological analysis indicated that MCC with a protein concentration of 12% would form gels greatly. The results of SDS-polyacrylamide gel electrophoresis showed that the contents of macromolecule in the gels increased as the heat treatment time is prolonged. After heat treatment, a fibrillated structure and a more stable structure were obtained in MCC-LGG gels by scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. The different changes of rheological behavior and texture of the gels were evaluated using a rheometer and texture analyzer, respectively. Similarly, centrifugation could reduce the property modified by heat inducing and contribute to LGG embedding completely. Importantly, LGG with a survival rate of 7.12% was in the gels after heat treatment at 75 °C for 10 min. Results showed that MCC could offer a protecting circumstance for living LGG cells from heat treatment. Therefore, MCC-LGG gels would be a potential healthy food for improving intestinal microflora in the dairy industry.

中文翻译：

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使用微滤嵌入鼠李糖乳杆菌GG（LGG）的微滤酪蛋白浓缩液（MCC）制备递送凝胶：温度对结构，流变行为和质地的影响。

为了获得天然蛋白凝胶作为载有益生菌的传递系统并保护益生菌免受热处理，我们使用胶束酪蛋白浓缩物（MCC）通过微滤制备了酪蛋白基凝胶，然后将其与鼠李糖乳杆菌一起包埋。GG（LGG）。流变学分析表明，蛋白质浓度为12％的MCC会大量形成凝胶。SDS-聚丙烯酰胺凝胶电泳的结果表明，随着热处理时间的延长，凝胶中大分子的含量增加。热处理后，分别通过扫描电子显微镜和傅里叶变换红外光谱在MCC-LGG凝胶中获得原纤化结构和更稳定的结构。分别使用流变仪和质地分析仪评估凝胶的流变行为和质地的不同变化。同样，离心会降低热诱导改性的性能，并完全有助于LGG的包埋。重要的是，在75°C热处理10分钟后，凝胶中的LGG的存活率为7.12％。结果表明，MCC可以为活LGG细胞提供免受热处理的保护环境。因此，MCC-LGG凝胶将是潜在的健康食品，可改善乳制品行业的肠道菌群。