This research aimed to investigate the effects of the inoculation method and diverse ingredients on the quality properties and probiotics viability of pudding with milk and/or soymilk. The probiotic strain (Lactobacillus acidophilus, LA-5) was inoculated into the yogurt base and fermented until the pH is 5.10 ± 0.05. The fermented yogurt was added into pudding base (yogurt inoculation), or LA-5 was directly inoculated (direct inoculation). During the storage of the puddings at 4±1oC for 4 wks, the quality characteristics (pH, acidity, texture) and the probiotics viability of pudding were measured and compared. As a result, the puddings with yogurt inoculation showed significantly lower pH and higher acidity than those with direct inoculation. In texture properties, including hardness, chewiness, and gumminess, the addition of rice powder increased those in milk pudding more but the addition of inulin in the milk-soymilk pudding more. The addition of rice powder increased probiotics viability more than inulin in milk and milk-soymilk puddings. Therefore, adding rice and/or inulin can potentially improve the probiotics viability and quality characteristics of pudding.

In this study, soybean is used to produce soymilk according to various extracting methods and heating time. Specifically, the soy slurry is being filtered before being heated, or heated before being filtered. Following that the soymilk produced is freeze-dried to be powdered, and then, the quality characteristics of the powdered soymilk are mutually compared to determine the applicability of various food additives. The freeze-dried soymilk powder shows 2.03~6.35% of moisture content, and in terms of unit quantity, retained more proteins, which suggests that the ratio of protein extraction is higher than any other nutrients. Accordingly, the protein coefficient is significantly higher in soymilk powder being heated and processed than in raw soybeans. In particular, protein coefficient is the highest in the soymilk which is heated for 20 minutes before being filtered (SHBF20). The longer the heating time was, the trypsin inhibitor (TI) tended to be far less active. Such an inactivation seems to be more apparent in the “SHAF” soymilk powder than “SHBF” soymilk powder. Because protein had to be denaturated by heating for soymilk, the nitrogen solubility index (NSI) of soymilk powder is decreased considerably, while the protein digestibility, water absorption, emulsification and foaming activity all increase. Oil absorption tends to decrease slightly. As discussed above, the soymilk heated for 10 minutes after being filtered (SHAF10) and the soymilk heated for 20 minutes before being filtered (SHBF20) show optimum processing conditions for soymilk powder.