Detailed Processing Technology of Sweet Potato Milk Fermented Beverage

1. Process flow: sweet potato juice preparation -- inoculation and fermentation -- blending, homogenization -- bottling, sterilization.

2. Key points of process operation:

① Preparation of sweet potato juice: take fresh sweet potatoes, wash and peel, cut into small pieces, steam-cook with steam for 20 minutes, mash with a masher, add 2 times the amount of water and homogenize in a colloid mill for 5 minutes, adjust the pH value to 6.5 with sodium carbonate solution, fill while hot into a sterile container, and cool to 40°C for later use.

② Inoculation and fermentation: inoculate 5% mixed strains (Lactobacillus bulgaricus : Streptococcus thermophilus at 1:1) into the sweet potato juice, and culture at 37°C for 12 hours.

③ Blending and homogenization: blend at a ratio of 100 parts sweet potato juice to 5 parts skim milk, control the temperature at 60-65°C, and carry out homogenization treatment at a homogenization pressure of 20 MPa.

④ Bottling and sterilization: fill the blended and homogenized beverage into 250 mL glass bottles or other containers. After filling and sealing, carry out sterilization treatment under the condition of 85°C for 20 minutes. After sterilization, it should be cooled immediately, and it is then the finished product.