The production method of purple sweet potato powder is made through multiple processes, so purple sweet potato is rich in nutritional value, widely used and has a large planting area in China. However, fresh purple sweet potato is difficult to keep fresh for a long time because of its high water content, which leads to high nutrient consumption and serious disease loss during storage. Therefore, in order to prolong the supply time of purple potato, it must be dried. The key point of Shandong Lenong's experiment is to develop a kind of sweet potato powder to make it easy to store and prolong its storage time. This sweet potato powder can be used as an ingredient for steamed bread, flower rolls, bread, cakes, fillings, etc.

(1) operating procedures

Ingredients: purple potato, with three pulp colors: purple pulp, orange pulp and yellow pulp.

② process flow

Wash, peel, shred, dice, dry, crush (measure moisture) and package the three raw materials of purple potato.

(1) cleaning: it must be cleaned, which is related to the final quality of the product.

(2) Peeling: Clean the sweet potato skin with a bamboo knife, especially the concave part of the purple potato skin.

③ Slicing or shredding: cut peeled purple potato into potato chips or diced potatoes with a vegetable slicer.

④ Color protection: Prepare a 0.5% solution with salt, and soak the cut purple potato chips or diced potatoes in it for a few minutes.

⑤ Drying: Dry with drying equipment to ensure the hygiene of products, and pay attention to the temperature, which is generally between 45-50℃. The drying time can be determined according to the size of potato chips and silk, so that the final moisture content is below 6%.

⑥ crushing and packaging: the dried purple potato is crushed by a hammer crusher to make the fineness of the purple potato powder reach about 80 meshes.

(III) Results and Analysis Among the three kinds of dried purple sweet potato powder, purple and orange sweet potato powder are better in color, while yellow sweet potato powder is darker in color. Therefore, purple and orange sweet potato varieties were selected as raw materials. The sweet potato powder prepared by the above method can be used as food raw materials to make various foods. Such as sweet potato cake, sweet potato cake, sweet potato roll, sweet potato bread, etc. The preparation method can be steaming, boiling or frying.