Method for making purple yam chips through microwave vacuum low-temperature oil bath dehydration technology

Abstract

The invention discloses a method for making purple yam chips through a microwave vacuum low-temperature oil bath dehydration technology (VODT). The method includes the steps that fresh purple yam is cleaned, peeled and cut into chips, the chips are blanched for 30-120 s in water at the temperature of 95 DEG C-100 DEG C, spray cooling is carried out, and the chips are contained on a plate and frozen quickly for 24 h at the temperature of minus 35 DEG C; the thoroughly frozen purple yam chips are contained in a polytetrafluoroethylene material frame, the material frame is moved into a microwave vacuum low-temperature oil bath dehydration integrated machine, vacuumizing is carried out until the pressure is 0.095-0.098 Mpa, microwave heating is started until oil temperature rises to 80-105 DEG C, the material frame is soaked in hot oil to be heated, and water contained in the purple yam chips is greatly sublimated and evaporated for 20-25 min; after oil boiling becomes weaker, oil temperature rises again, the vacuum degree is stabilized at 0.095-0.097 Mpa, the hot oil in a kettle is pumped by an oil pump to a storage tank for use, and the material frame is centrifuged at the speed of 100-300 rpm for 2-5 min to remove oil on the surfaces of the purple yam chips; after centrifugation is stopped, the purple yam chips are taken out, seasoning is mixed while the purple yam chips are hot to obtain needed flavor through blending, and finished products are obtained after cooling and packaging. The produced purple yam chips can keep the color, the fragrance and nutrient ingredients of purple yam well, is fragrant, crispy, tasty and good in mouthfeel, and is leisure food having good market prospects.

Description

technical field [0001] The invention belongs to the field of food processing, and in particular relates to a method for making taro sticks using microwave vacuum low-temperature oil bath dehydration (VODT) technology, in particular to a dehydration process for taro stick processing using microwave vacuum low-temperature oil bath dehydration (VODT) technology . Background technique [0002] Vacuum low temperature oil bath dehydration (VODT) technology, also known as vacuum frying, is a relatively new food processing technology developed in the 1970s and introduced into China in the 1990s. This technology is mainly based on the principle of lowering the boiling point of water in food under vacuum conditions to achieve food dehydration under high vacuum and low temperature conditions. At present, it is mainly used in the processing of fruit and vegetable raw materials, and is the main processing technology of fruit and vegetable crisps. The processing temperature of this techn...

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Problems solved by technology

[0003] In the traditional vacuum low-temperature oil bath dehydration technology, steam is mainly used as the heat source. Fruit and vegetable processing plants need to be equipped with boilers. For some small manufacturers with only a few sets of equipment, the investment cost and operating cost of the enterprise are increased.

At the same time, the use of steam heating has undergone multiple heat conversions, with low thermal efficiency and relatively high energy consumption. The temperature difference between the steam temperature and the oil temperature is small, and the heat transfer efficiency is reduced. A large-area heat exchanger is required, which increases equipment investment.

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