Deep processing of sweet potatoes brings good returns, giving farmers a new way to increase their income

I. Crispy rice crust 1. Raw material preparation. Select 10 parts of fresh sweet potatoes with a high dry matter content, cut off the roots and stems, and wash them with water. Separately select 1 part of highly sticky glutinous rice, soak it in water and wash it for 30 minutes, then drain off the water. Next, put the sweet potatoes and glutinous rice into separate pots, add water, and steam them thoroughly over high heat for later use. Then put the mashed cooked sweet potatoes and glutinous rice, while still hot, into a bucket, and quickly pound them with a thick stick into a paste. At the same time add a small amount of white sugar water to increase sweetness and flavor.

2. Spreading the paste. Take a clean cloth sheet and spread it flat on a sun-drying mat, press down the four sides with heavy objects, then slowly pour the evenly pounded paste onto the cloth sheet, and quickly use the kind of trowel used for plastering walls to press and spread it evenly, spreading it as thin as possible. Then sprinkle a layer of sesame seeds on the paste.

3. Drying. Lift the two corners of the cloth sheet with both hands and place it lightly on a bamboo pole in a cool, shady place to dry, to prevent cracking from sun exposure. Then lay the dried cloth sheet face down on the sun-drying mat with the sweet potato skin facing down, soak the cloth sheet thoroughly with a wet towel, and quickly peel off the sweet potato skin piece by piece, then sun-dry or oven-dry it to prevent mold, and afterward cut it into various shapes of 3.3-6.6 cm square.

4. Deep-frying. Put the dried sweet potato skin into rapeseed oil at 140-160°C and fry for 3-5 minutes, until the surface of the sweet potato skin gradually turns yellow but is not burnt, then take it out, drain off the oil, and it is the finished product.

II. Flavored sweet dates

1. Raw material preparation. Choose sweet potato varieties with red or yellow flesh that have a high sugar content, little starch, and much moisture as the raw material. After harvesting, leave them for 15-20 days first, so that their starch is saccharified.

2. Steaming and cutting into pieces. Remove the head and tail of the sweet potatoes, wash them, steam them in a steamer until cooked, take them out, let them cool, peel off the skin, and then cut them into small pieces 5-6 cm long and 2-3 cm thick.

3. Baking. Put the cut small sweet potato pieces in the sun to dry or place them in an oven to bake, and gently turn them while drying (baking), taking care not to damage their original shape. Dry or bake until the moisture content of the sweet potato pieces is about 35%.

4. Shaping. Process the dried and baked small sweet potato pieces into oval shapes, then dry or bake them again until the moisture content is about 20%, and they become sweet potato sweet dates. The finished product has a beautiful appearance and a unique flavor, and has now been exported to various countries in Southeast Asia.

III. Sweet potato-flavored tofu

Sweet potato tofu has the characteristics of a mild taste, white color, and high nutritional value. Its processing method: first wash the soybeans and soak them in water for 15 hours (the soaking time in winter is about 24 hours), use a grinder to grind the soaked soybeans into a slurry while adding a small amount of water, then pour it into a vat and stir. Filter the resulting soybean milk to remove the residue, and mix every 7 liters of soybean milk liquid with about 700 grams of pasty sweet potato starch that has been pre-ground with a grinder. Then pour it into an iron pot and boil it, keep the temperature at about 100°C, stir gently for 1 minute, then add 50 grams of coagulant. At this point, the protein of the soybeans and sweet potatoes will gradually coagulate and separate out. Let it stand for a moment, pour it into a box provided with a filter cloth, press out the water and remove it from the box, cut it into pieces of an appropriate size, and cool it to obtain sweet potato tofu.

IV. Sweet potato bean paste

1. Raw material formula. 45 kg sweet potatoes, 15 kg black beans, 20 kg white granulated sugar, 1.5 kg vegetable oil, 0.2 kg caramel coloring, and a sufficient amount of water.

2. Processing key points. ① Treatment of raw and auxiliary materials. Choose fresh or winter-stored high-quality sweet potatoes and superior black beans, wash them with clean water, then soak the black beans in warm water for 3-4 hours; dissolve the granulated sugar with purified water and filter it to prepare a 75% sugar liquid; separately dissolve the caramel coloring with an appropriate amount of water, add the vegetable oil and stir evenly into an emulsion for later use.

② Pan-cooking and boiling. Put the treated sweet potatoes into a pan-cooking pot and heat them with steam until cooked, with no hard core; put the black beans into a jacketed pot and heat them with steam until fully soft and mushy. During the cooking process, prevent the sweet potatoes and black beans from burning.

③ Mixing to make paste. Let the cooked sweet potatoes cool and peel them by hand, mince them into pieces with a knife or other tool, then mix them with the cooked black beans in a certain proportion, and grind them into a paste with a beater or mill.

④ Blending. Place the material paste in a blending bucket, add the treated auxiliary materials, and stir mechanically until the color is uniform and consistent, while heating to 80°C.

⑤ Bagging, sterilization, and cooling. Fill the semi-finished product into retort pouches with a filling machine, in specifications of 500 grams or 250 grams per bag, heat-seal after vacuum exhausting, sterilize under high pressure for 45 minutes, and cool to 45°C to obtain the finished product.

V. Multi-flavor sweet potato cakes

1. Raw material formula. 1 kg sweet potatoes, 1 kg potatoes, 0.8 kg soybeans, 0.6 kg corn starch, 0.5 kg pork, 0.4 kg eggs, 20 grams monosodium glutamate, 30 grams table salt, 68 grams sweet baking powder.

2. Raw material pretreatment. Peel the sweet potatoes and potatoes and steam them until cooked, mash them into sweet potato paste with a masher, beat the eggs into egg batter with an egg beater, with the time controlled at about 2 minutes. Mince the pork and steam it until cooked; first stir-fry the soybeans until cooked, then grind them and pass them through a 40-mesh sieve.

3. Mixing and stirring. After the sweet potato paste and meat filling have cooled, mix them, pour in the egg liquid and stir evenly; mix the soybean powder, corn starch, salt, monosodium glutamate, and sweet baking powder. Then mix and stir the above two items, and adjust the dryness and wetness of the mixed material to facilitate the shaping of the blank.

4. Pressing the blank. Control the thickness of the pressed blank at 4-5 mm. The specification and shape are generally oval or rectangular. The weight is 50 grams.

5. Drying. Put it into a constant-temperature oven, control it between 65-70°C, and dry for 25 minutes; after drying, control the moisture at about 10%.

6. Deep-frying. Use edible palm oil as the frying oil, control the oil temperature between 170-180°C, and the frying time at about 30 seconds; fry until the surface of the sweet potato cake is golden yellow and the inside is crisp. After deep-frying, naturally cool to below 38°C, and after packaging it is the finished product.