阅读说明：本技术 一种脱水蔬菜的制备方法 (A method for preparing dehydrated vegetable ) 是由 谢高峰 于 2020-06-05 设计创作，主要内容包括：本发明公开了.一种脱水蔬菜的制备方法,其步骤包括：原料→清理→浸泡→清洗→沥干水分→切制→护色剂浸泡→漂烫→冷冻干燥→微波干燥→灭菌→包装成品。脱水蔬菜制品可保留原有光泽,蔬菜脱水后其含水率为4％～6％,水分活度在0.5～0.6。脱水蔬菜低含水率使微生物和酶处于低生命活性状态,防止了微生物,特别是致病菌的生长繁殖,达到防腐、保鲜的效果。(The invention discloses a preparation method of dehydrated vegetables, which comprises the following steps: raw materials → cleaning → soaking → cleaning → draining water → cutting → color fixative soaking → blanching → freeze drying → microwave drying → sterilization → packaging finished product. The dehydrated vegetable product can keep the original luster, the water content of the dehydrated vegetable is 4-6%, and the water activity is 0.5-0.6. The low water content of the dehydrated vegetables enables microorganisms and enzymes to be in a low-activity state, prevents the growth and propagation of microorganisms, particularly pathogenic bacteria, and achieves the effects of corrosion prevention and fresh keeping.)

1. a method for preparing dehydrated vegetables comprises the steps of: raw materials → cleaning → soaking → cleaning → draining water → cutting → color fixative soaking → blanching → freeze drying → microwave vacuum drying → sterilization → packaging finished product.

2. The method of claim 1, wherein the dehydrated vegetable is prepared by: the color fixative is soaked, and comprises the following components in parts by mass: 12-23 parts of D-sodium erythorbate, 12-21 parts of disodium ethylene diamine tetraacetate, 7-10 parts of sodium citrate and 2-7 parts of sodium tripolyphosphate.

3. The method of producing a dehydrated vegetable according to claim 1 or 2, wherein: and soaking the color fixative, preparing the color fixative and water into an aqueous solution, and soaking the vegetables, wherein the mass fraction of the aqueous solution is 3-8%.

4. The method of claim 1, wherein the dehydrated vegetable is prepared by: and blanching for 30-50 seconds at 91-94 ℃.

5. The method of claim 1, wherein the dehydrated vegetable is prepared by: the freeze drying comprises the following steps: rapidly freezing to a temperature below-15 ℃ for at least 2 hours; and then, drying for 8-10 hours in vacuum in an environment with the vacuum degree of 10-50 Pa and the temperature of 55-60 ℃.

6. The method of claim 1, wherein the dehydrated vegetable is prepared by: the microwave vacuum drying is carried out under the process conditions that the vacuum pressure is 3-5 MPa, the drying temperature is 45-50 ℃, the microwave power is 15-20kW, the drying time is 50-70min, and the drying is carried out until the water content is 4-6%.

7. The method of claim 1, wherein the dehydrated vegetable is prepared by: the sterilization is irradiation sterilization: the radiation dose is controlled between 5kGy and 10kGy, and the irradiation time is at least 60 minutes.

Technical Field

The invention relates to the technical field of vegetable processing, in particular to a preparation method of dehydrated vegetables.

Background

The technical means adopted at present for keeping and controlling the quality of vegetables are quite many, such as normal-temperature moisture preservation storage, low-temperature storage, plastic packaging storage, chemical agent storage, quick-freezing fresh-keeping storage, radioactive ray irradiation and the like, and the above means have the defects of high processing cost, poor fresh-keeping effect and the like. Can not meet the requirements of the modern market.

The dehydrated vegetable is prepared by washing and drying fresh vegetable, so that its water content is reduced, and its color and nutrient components are basically retained. The dehydrated vegetables are easy to store, transport and sell, can effectively regulate the light and vigorous season of vegetable production, and are popular in domestic and foreign markets.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: provides a preparation method of dehydrated vegetables which can keep the original luster of the vegetables and is long-lasting in storage.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: a method for preparing dehydrated vegetables comprises the steps of: raw materials → cleaning → soaking → cleaning → draining water → cutting → color fixative soaking → blanching → freeze drying → microwave vacuum drying → sterilization → packaging finished product.

The color fixative in the color fixative soaking comprises the following components in parts by mass: 12-23 parts of D-sodium erythorbate, 12-21 parts of disodium ethylene diamine tetraacetate, 7-10 parts of sodium citrate and 2-7 parts of sodium tripolyphosphate.

And soaking the color fixative, preparing the color fixative and water into an aqueous solution, and soaking the vegetables, wherein the mass fraction of the aqueous solution is 3-8%.

And blanching for 30-50 seconds at 91-94 ℃. The color protecting agent is selected to be used for color protection by soaking and blanching, and the blanching can destroy an oxidase system in the vegetables, prevent browning and oxidation of nutrient substances, and have a certain sterilization effect.

The freeze drying comprises the following steps: rapidly freezing to a temperature below-15 ℃ for at least 2 hours; and then, drying for 8-10 hours in vacuum in an environment with the vacuum degree of 10-50 Pa and the temperature of 55-60 ℃.

The microwave vacuum drying is carried out under the process conditions that the vacuum pressure is 3-5 MPa, the drying temperature is 45-50 ℃, the microwave power is 15-20kW, the drying time is 50-70min, and the drying is carried out until the water content is 4-6%.

The sterilization is irradiation sterilization: the radiation dose is controlled between 5kGy and 10kGy, and the irradiation time is at least 60 minutes.

Has the advantages that: the dehydrated vegetable product can keep the original luster, the water content of the dehydrated vegetable is 4% -6%, the water activity is 0.5-0.6, and the rehydration ratio is 1: (4-8), the freshness can be recovered after 3-10 min. The low water content of the dehydrated vegetables enables microorganisms and enzymes to be in a low-activity state, prevents the growth and propagation of microorganisms, particularly pathogenic bacteria, and achieves the effects of corrosion prevention and fresh keeping. The product can be stored for a long time of 2-3 years in a low-temperature storage mode by sealing or vacuum packaging.

Detailed Description

The process of the present invention is further illustrated below with reference to examples, but the invention is not limited thereto.

A method for preparing dehydrated vegetables comprises the steps of: raw materials → cleaning → soaking → cleaning → draining water → cutting → color fixative soaking → blanching → freeze drying → microwave vacuum drying → sterilization → packaging finished product.

The color fixative in the color fixative soaking comprises the following components in parts by mass: 13 parts of D-sodium erythorbate, 18 parts of disodium ethylene diamine tetraacetate, 8 parts of sodium citrate and 3 parts of sodium tripolyphosphate.

And soaking the color fixative, preparing the color fixative and water into an aqueous solution, and soaking the vegetables, wherein the mass fraction of the aqueous solution is 5%.

And blanching for 30-50 seconds at 91-94 ℃. The color protecting agent is selected to be used for color protection by soaking and blanching, and the blanching can destroy an oxidase system in the vegetables, prevent browning and oxidation of nutrient substances, and have a certain sterilization effect.

The freeze drying comprises the following steps: rapidly freezing to a temperature below-15 ℃ for at least 2 hours; and then, drying for 8-10 hours in vacuum in an environment with the vacuum degree of 10-50 Pa and the temperature of 55-60 ℃.

The microwave vacuum drying is carried out under the process conditions that the vacuum pressure is 3-5 MPa, the drying temperature is 45-50 ℃, the microwave power is 15-20kW, the drying time is 50-70min, and the drying is carried out until the water content is 4-6%.

The sterilization is irradiation sterilization: the radiation dose is controlled between 5kGy and 10kGy, and the irradiation time is at least 60 minutes.

The obtained dehydrated vegetable product is detected:

(1) color: has the color of the raw materials.

(2) Fragrance: has the flavor of the variety (or the flavor after cooking).

(3) Granularity: meets the specification requirement, wherein the powder content is 2 percent.

(4) The water content is less than or equal to 5 percent

(5) The total number of the microbial bacteria is less than or equal to 500/g; coliform group is less than or equal to 10 per 100 g; pathogenic bacteria: not detected or determined according to the requirements of the client.

(6) Heavy metal arsenic (calculated by As) is less than or equal to 1.0 mg/kg; lead (calculated by Pb) is less than or equal to 2.0 mg/kg; copper (calculated by Cu) is less than or equal to 60 mg/kg.

Taking 5 g of dehydrated vegetable product, soaking in water at 50-55 ℃ for 10 minutes, fully rehydrating, taking out, draining, air-drying surface moisture, accurately weighing, and calculating the rehydration ratio as 1: 6.2.