Optimization of Microencapsulated Lactobacillus rhamnosus GG from Whey Protein and Glutinous Rice Starch by Spray Drying

Lactobacillus rhamnosus GG is commonly used as probiotic dietary supplements that show poor survival rate in dairy products during processing, storage and gastrointestinal tract, however, using encapsulated probiotics could be an interesting option. Spray drying is the most widely used encapsulation technique in the food industry. It offers the attractive advantage of microencapsulation in low operating costs, high quality and stability, rapid solubility and continuous operation. The encapsulating agent of microcapsules affects probiotic survival. The aim of this study was to optimize the microencapsulation of Lactobacillus rhamnosus GG (LGG) by spray drying using whey protein and glutinous rice starch as encapsulating agents. The composition ratio between glutinous rice starch and whey protein and spray drying parameter of inlet temperature was evaluated using response surface methodology (RSM). These results showed that 80 % of glutinous rice starch replacement in whey protein wall and inlet temperature of 143°C provided the desired LGG microcapsules with high percentage of process yield (over 74.44 ± 3.95%) and survival rate (over 97.83 ± 2.01%).