How to make sweet potato golden shreds? Detailed production process analysis
Sweet potato is also called yam, red yam, sweet potato, white potato, earth potato, red potato, fan shu, etc. It belongs to the Convolvulaceae family, Ipomoea genus, sweet potato species, and is a trailing herbaceous plant that remains evergreen year-round in the tropics and is perennial. The sweet potato has strong adaptability and stress resistance, is drought-tolerant, barren-tolerant, and alkali-tolerant, has low requirements for soil conditions, and has a strong ability to recover and regenerate after insect damage. Under poor soil conditions and low fertilization levels, it can yield more than a thousand jin of fresh tubers per mu. Sweet potato has a wide range of industrial uses, but in rural areas it is mostly used as feed, and its economic value cannot be well realized. Making fresh sweet potato into sweet potato golden shreds can preserve the flavor and nutritional value of the fresh fruit, and the equipment is simple, the technology is easy to master, and it is easy to promote in rural areas and small enterprises.
I. Process requirements
Raw material selection: Yunnan sweet potatoes are mostly of three varieties: red-skinned sweet potato, white-skinned yellow-fleshed sweet potato, and white-skinned white-fleshed sweet potato. Red-skinned sweet potato should be selected; this variety has high yield, high water content, and good color in the finished product.
Peeling: Use a stainless steel knife, peel in water or drop into water as you peel. Submerge in water to prevent oxidation and discoloration.
Cutting into strips: Use a stainless steel knife to cut them into thin strips of 60mm×6mm×6mm. The cuts should be smooth, with no dirt or impurities. Put the thin strips into water immediately and submerge them.
Color protection: Soak in a mixed solution of 0.2% calcium chloride and 0.4% sodium bisulfite for 1 hour; the sulfur fumigation method can also be used. The amount of sulfur depends on the water content of the potato strips. Generally, when the water content is 35%——45%, the amount of sulfur is 0.15%——0.2% of the weight of the potato strips; when the water content of the potato strips is 25%——5%, the amount of sulfur is 0.1%——0.15% of the weight of the potato strips, and fumigate for 3 hours.
Washing: Rinse the raw materials after color protection treatment repeatedly until there is no calcium taste or sulfur taste.
Pre-boiling: Pre-boil the rinsed potato strips in 90°C warm water for 10 minutes, then remove and rinse again.
Sugar boiling: Weigh sugar equal to 10——15% of the weight of the thin strips and mix well with the thin strips, and soak in sugar for 1 day. The next day, remove and filter out the sugar liquid, then take sugar equal to 10% of the weight of the thin strips and boil with the thin strips in boiling water at 100°C——105°C, stirring constantly, and boil until there is no raw taste (for raw materials fumigated with sulfur, the boiling time is relatively shorter). Quickly put them into a jar together with the sugar liquid, soak in sugar for 1 day, filter out the sugar liquid, and rinse the sugar liquid on the surface of the thin strips with cool boiled water.
Baking: Spread the thin strips on a baking tray and send them to the drying room. The baking temperature is 55°C——60°C, and bake until the sweet potato has lost about 65——70% of its water.
Resting: Cool the potato strips to room temperature, put them into jars, boxes, or pile them on boards with a pile thickness of 40——50 cm, and cover them with reed mats, burlap sacks, or plastic film. After 4——5 days, after the sweet potato strips soften, the soluble substances inside seep outward. Take them out and spread them in a ventilated and cool place, and air-dry the surface.
Packaging: Use polyethylene film bags. After quantitatively packing the product according to requirements, package it with an inflatable packaging machine for market, or it can also be sold in bulk.
II. Quality standards
The finished product is golden yellow in color, slightly sweet with a glutinous texture, refreshing and cool in the mouth, contains the original flavor of sweet potato, and when rubbed by hand the potato strips do not stick to the hand and do not deliquesce.