Abstract To maintain viable cells over the critical value of 106 cfu g-1 throughout shelf life of probiotic yoghurt, Lactobacillus acidophilus LA-5 was encapsulated by spray drying using whey powder (WP) and gum arabic (GA) mixtures. Box-Behnken Design (BBD) method was used to optimise drying conditions and WP to GA ratio in wall material. Responses were recorded for encapsulation efficiency and production efficiency of microcapsules. Optimum conditions were determined as: inlet air temperature, 140 °C; liquid flow rate, 0.485 L h-1; WP to GA ration 0.83:0.17 (dry weight basis), resulting in 93.95% maximum encapsulation efficiency and 48.36% maximum production efficiency. After exposure to simulated gastrointestinal conditions, the microcapsules produced under optimum conditions provided better protection of L. acidophilus, when compared with free cells, with a reduction of 10.84% and 24.54%, respectively. Particle size of microcapsules was D50:6.276 μm, which is acceptable for incorporation into dairy and other food products.

中文翻译：

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乳清和阿拉伯树胶中嗜酸乳杆菌封装喷雾干燥参数的优化：其在酸奶中的应用

摘要 为了在益生菌酸奶的整个保质期内维持活细胞超过 106 cfu g-1 的临界值，嗜酸乳杆菌 LA-5 使用乳清粉 (WP) 和阿拉伯树胶 (GA) 混合物通过喷雾干燥进行封装。Box-Behnken Design (BBD) 方法用于优化壁材中的干燥条件和 WP 与 GA 的比率。记录对微胶囊的包封效率和生产效率的响应。最佳条件确定为：入口空气温度，140 °C；液体流量，0.485 L h-1；WP 与 GA 的比例为 0.83:0.17（干重），导致 93.95% 的最大包封效率和 48.36% 的最大生产效率。暴露于模拟胃肠条件后，在最佳条件下产生的微胶囊对嗜酸乳杆菌提供了更好的保护，与游离细胞相比，分别减少了 10.84% 和 24.54%。微胶囊的粒径为 D50:6.276 μm，可用于掺入乳制品和其他食品中。