A method of vacuum drying and positive and negative high-pressure low-temperature fermentation technology to prepare spicy frosted sweet potato leaf shreds

Abstract

The invention discloses a method for preparing spicy frosted sweet potato leaf shreds by adopting vacuum drying and positive-negative high-pressure low-temperature fermentation technologies. The method comprises the following steps that: sweet potato leaves are subjected to three-section microwave vacuum drying until the moisture content is 10 percent to 20 percent; and low-temperature fermentation is carried out by adopting three-stage positive-negative high-pressure penetration technology. The start fermentation is carried out at the temperature of 25 DEG C to 28 DEG C and under the pressure of 0.1MPa to 0.2MPa for 30 minutes to 40 minutes; then, the pressure is released, and vacuumization is carried out until the vacuum degree is -0.05MPa to -0.1MPa; and the state is maintained for 5 minutes to 10 minutes. Thereafter, the vacuum is relieved to restore the normal pressure, and the second-stage positive-negative high-pressure penetration fermentation and the third-stage positive- negative high-pressure penetration after-ripening fermentation are carried out. The spicy frosted sweet potato leaf shreds prepared by the method are spicy, delicious, nutritious and healthy, and can be produced at a high speed. Besides, the sweet potato leaf shreds are not prone to bacterial contamination.

Description

technical field [0001] The application belongs to the technical field of food processing, and relates to a method for preparing fragrant and spicy frosted sweet potato shreds by vacuum drying and reverse high-pressure low-temperature fermentation technology. Background technique [0002] Sweet potato leaves, also known as sweet potato leaves, sweet potato leaves. Sweet potato leaf is a very nutritious vegetable, its nutritional value is much higher than that of sweet potato, and its protein and fat content, especially inorganic salt content is very high. According to determination, every 100 grams of sweet potato leaves contains 2.8 grams of protein, 0.8 grams of fat, 4.1 grams of carbohydrates, 1.1 grams of crude fiber, 16 mg of calcium, 34 mg of phosphorus, and 2.3 mg of iron. In addition, sweet potato leaves also contain carotene, riboflavin, nicotinic acid, ascorbic acid and other ingredients. Sweet potato leaves are flat and sweet, non-toxic, and taste a bit like wate...

AI Technical Summary

Problems solved by technology

Along with people's pursuit of nutritious meals, sweet potato leaves gradually come to people's dining tables, but their eating methods are still very single, almost all of which are used in kitchen cooking, and there are no instant foods made of sweet potato leaves as raw materials.

[0003] Lactic acid fermentation is used in the traditional pickling of leafy vegetables. The content and quality of naturally proliferating lactic acid bacteria are extremely unstable due to various factors, which not only directly affects the final fermentation effect, but also is difficult to industrialize due to the existence of various unstable factors. Large-scale and standardized production

In addition, the fermentation temperature of the bacteria is generally between 25 and 35°C, and under this environment, it is very easy to cause the rot of the fermented leafy vegetables, so the quality of the fermented leafy vegetables is difficult to guarantee

Moreover, the fermentation cycle in traditional fermentation is generally relatively long in a few days, and the time-consuming fermentation cycle directly affects the production efficiency

Therefore, it is difficult to realize large-scale high-speed industrial production if the traditional fermentation method is still used to make fermented spicy sweet potato shreds