Processing of preserved Sweet Potato

1. Raw and auxiliary materials: fresh sweet potato, granulated sugar, sugar, citric acid, sodium sulfite, edible gelatin, quicklime and so on.

2. Technological process: sweet potato-cleaning-peeling-slicing-color protection-hardening-blanching-dipping-sugar boiling-sugar soaking-baking-packaging-finished product

3. Key points of process operation:

① cleaning: choose fresh potatoes that are compact, non-invasive, non-polluting, non-rotten and round in shape, and wash the soil by machine or by hand.

② peeling: use a peeling machine or manual peeling to remove potato skins. About 1 mm thick, leaving potato heart.

③ syncopation: cut into rectangle, diamond and other shapes according to product requirements to make the product appearance beautiful and generous. After cutting, wash off the crumbs and starch attached to the surface of the potato pieces with clean water.

④ color protection: put the cut potato pieces in 0.3% 0.5% sodium sulfite solution, soak for 90 minutes for 100 minutes, then rinse with clean water for 5 minutes for 10 minutes.

⑤ hardening: soak the potato pieces with good color protection in 0.2%-0.5% fresh lime solution for 12-16 hours, then take them out after completely hardening, rinse with clean water for 10-15 minutes.

⑥ blanching: put the hardened potato pieces into boiling water and boil for a few minutes, remove and drain.

⑦ dipping: put the blanched potato into 0.3% 0.5% gelatin solution, reduce pressure, vacuum 650-680 mm Hg, time 30-50 minutes, glue temperature about 50 degrees Celsius.

⑧ sugar boil, sugar stains: put 20kg white granulated sugar and 30kg water into stainless steel pot to make sugar solution, take out 7.5kg sugar solution for later use, add 1.5kg maltose to the remaining sugar solution, stir and boil the solution, pour in 50kg sweet potato blocks and boil for 5 minutes, immediately add 1.5kg cold sugar solution reserved in advance. Boil the sugar solution again for 5 minutes and add 1.5 kg cold sugar solution. After such repeated three times, when the sugar solution is boiled again, 1.5 kg of granulated sugar and 1 kg of cold sugar are added at the same time for three times, 7.5 kg of granulated sugar is added after the fourth boiling, and 3 kg of granulated sugar is added after boiling again, and use a gentle heat to boil until the potato pieces are transparent, 75 grams of citric acid can be added, stir evenly and remove the potato pieces to control the sugar removal solution. The preserved sweet potatoes made by this method are crystal clear and bright, with good taste and color. You can also put spare potato pieces into the pot, add 75kg of water, 20kg of granulated sugar, 1.5kg of caramel, 100g of citric acid, boil the pot with high heat as soon as possible, about half an hour, so that the potatoes are cooked but not rotten. Due to the variety of sweet potato, the sugar boiling time is also different. Put the potato pieces and sugar solution out of the pot and soak them in a large vat for 24 hours to make the potato pieces eat further sugar. Then remove the impregnated potatoes, spread the single layer flat on the drawer or bamboo mat, and drain the sugar.

⑨ baking: drain the sugar solution and send it to the baking room to bake, keeping the temperature at 60-70 degrees Celsius. Pay attention to adjust the position and turn frequently, and should be treated with moisture removal every 2-3 hours to shorten the baking time. Generally continuous baking for about 12 hours, so that the water content of potato pieces is reduced to 16%-18%, hands do not stick to hands, slightly elastic when out of the room. You can also put the potato pieces in the hot sun to dry, and turn the potato pieces from time to time.

⑩ plastic packaging: remove the crumbs and shapeless pieces from the potato chips that are qualified for room or air drying and store or sell them in food bags according to a certain weight. If you want to produce multicolor preserved potato, the potato cubes can be divided into several parts before boiling with sugar solution, and when the sugar is boiled, various natural food pigments of the specified amount can be put into the pot to make the multicolor preserved potato with attractive color.