The Effect of Milk Protein on the Biological and Rheological Properties of Probiotic Capsules

Probiotics are often infused into functional foods or encapsulated in a supplement form to maintain a healthy balance between the gut microbiota and their host. Because there are milk-based functional foods such as yogurt and cheese on the market, it has been suggested that milk-based probiotics could be incorporated into skim milk proteins in a liquid capsule. Skim milk is mainly composed of casein and whey protein, which create a strong natural barrier and can be used to encapsulate probiotics. In this study, we compared the encapsulated probiotics prepared with milkbased concentrated cell mixtures using commercial probiotics. Probiotic capsules were emulsified with skim milk proteins using vegetable oil to form a double coating layer. The product was heatstable when tested using a rheometer. The survival rate of the milk-based probiotic cells in the lower gastric environment with bile was significantly higher than commercial probiotics. Thus, milkencapsulated probiotics exhibited greater efficacy in the host than other types of probiotics, suggesting that the former could be more viable with a longer shelf life under harsh conditions than other form of probiotics. Our findings suggested that, compared with other types of probiotics, milkbased probiotics may be a better choice for producers and consumers.