阅读说明：本技术 一种延长芦笋贮藏期的保鲜方法 (Fresh-keeping method for prolonging storage period of asparagus ) 是由 范柳萍 王建 李进伟 于 2019-12-31 设计创作，主要内容包括：本发明公开了一种延长芦笋贮藏期的保鲜方法,属于农产品贮藏保鲜技术领域的应用。所述保鲜方法是将芦笋经超声、保鲜剂处理后,再进行气调包装。该发明方法很好地抑制了芦笋的腐烂变质,表面菌落总数、霉菌和酵母菌总数分别下降了约1.5个log和2个log；同时该发明方法抑制芦笋的呼吸作用,保留了可溶性固形物、Vc和叶绿素含量,抑制了木质素的生成,从而保持芦笋的品质,可使芦笋的贮藏期延长至40天。本方面根据芦笋品质特点,工艺流程设计合理、成本低和适用于工业化生产。(The invention discloses a preservation method for prolonging the storage period of asparagus, belonging to the application of the technical field of storage and preservation of agricultural products. The fresh-keeping method is that the asparagus is treated by ultrasound and fresh-keeping agent and then is packaged in modified atmosphere. The method well inhibits the decay and deterioration of the asparagus, and the total number of surface colonies, the total number of moulds and yeasts are respectively reduced by about 1.5 logs and 2 logs; meanwhile, the method inhibits the respiration of the asparagus, reserves the content of soluble solid, Vc and chlorophyll, and inhibits the generation of lignin, thereby keeping the quality of the asparagus and prolonging the storage period of the asparagus to 40 days. According to the quality characteristics of the asparagus, the process flow is reasonable in design, low in cost and suitable for industrial production.)

1. ExtensionThe fresh-keeping method for asparagus in the storage period is characterized in that the fresh-keeping method comprises the steps of treating asparagus by ultrasound and a fresh-keeping agent, and then performing controlled atmosphere packaging, wherein the gas component in the controlled atmosphere packaging is O₂5-15% and CO₂Is 5-15%.

2. A method for improving asparagus nutritional quality is characterized in that asparagus is subjected to ultrasonic treatment and fumigation by 1-methylcyclopropene, and then subjected to modified atmosphere packaging, wherein the gas component in the modified atmosphere packaging is O₂5-15% and CO₂Is 5-15%.

3. The method as claimed in claim 1 or 2, wherein the ultrasonic power is 100-360W, and the ultrasonic time is 5-15 min.

4. The method of claim 1, wherein the preservative is a composite preservative of acetic acid and gibberellin or a preservative of 1-methylcyclopropene.

5. The method as claimed in claim 4, wherein the concentration of acetic acid in the acetic acid + gibberellin composite preservative is 10-30mL/L, and the concentration of gibberellin is 25-50 mg/L.

6. The method as claimed in claim 2 or 4, wherein the mass concentration of 1-methylcyclopropene is 0.1-1g/5kg of asparagus, i.e. the amount of 1-methylcyclopropene added is 0.002% -0.02% of asparagus mass.

7. Method according to claim 1 or 2, characterized in that it comprises the following steps:

(1) selecting high-grade asparagus with stem length of 25cm, diameter of 16-18mm, no bending, no mechanical damage, no abrasion and no rot;

(2) treating the superior asparagus selected in the step (1) by ultrasonic, immersing the asparagus into an ultrasonic generator containing water, selecting ultrasonic power of 100-;

(3) soaking the asparagus treated in the step (2) in a preservative for 5-15min, then taking out, and quickly draining;

(4) performing controlled atmosphere packaging on the asparagus obtained by the treatment in the step (3) by using a controlled atmosphere packaging machine, wherein the gas component in the controlled atmosphere packaging is O₂5-15% of CO₂5-15% and N₂80-100%;

(5) and (3) refrigerating the asparagus subjected to modified atmosphere packaging, wherein the refrigerating temperature is 2-5 ℃, and the relative humidity is 80-90%.

8. The method as claimed in claim 7, wherein the low density polyethylene antibacterial freshness protection package is used for packaging, and the thickness of the low density polyethylene antibacterial freshness protection package is 2-10 mm.

9. The method of claim 1, wherein the preservation comprises mildew and rot resistance, yellowing resistance, and lignification resistance.

10. The method of claim 1 or 2, applied to the aspects of fruit and vegetable fresh-keeping and nutrition quality enhancement.

Technical Field

The invention relates to a preservation method for prolonging the storage period of asparagus, belonging to the technical field of storage and preservation of agricultural products.

Background

Green Asparagus (Asparagus officinalis L.) is named as Asparagus and Asparagus, belongs to Asparagus plants in Liliaceae, and is known as the king of vegetables in the international market. The asparagus is rich in nutrition and various nutrient elements such as vitamins, inorganic salts, polyphenol and the like. Besides, the asparagus has high medicinal value, and modern medical research proves that the asparagus not only can enhance physical strength of people and eliminate fatigue, but also has prevention effects on atherosclerosis, cancer resistance and the like.

However, the asparagus tender stems have high water content, so that the asparagus tender stems can breathe vigorously after being harvested, and a large amount of nutrient substances are consumed, and the asparagus tender stems are green and yellow and accumulate lignin. The asparagus is very sensitive to temperature change, the asparagus is yellow and wilted only 2 to 4 days at room temperature, and the cuts are easy to be infected and corrupted, so that the quality is deteriorated, the commodity value is reduced, and the earning of asparagus exports and the domestic market expansion are restricted to a great extent. Therefore, the method has very important significance on prolonging the storage period of the asparagus and improving the fresh-keeping quality of the asparagus product.

At present, the postharvest fresh-keeping technology for asparagus at home and abroad mainly comprises methods such as precooling, refrigeration, radiation treatment, heat treatment, modified atmosphere treatment and the like, but the problems of difficult storage and easy decay of the green asparagus at home and abroad cannot be solved at present. The microorganisms are the main cause of asparagus spoilage, so that the asparagus needs to be sterilized, the rotting rate during storage is reduced, the nutritional quality of the asparagus needs to be maintained to a greater extent, and the method has great practical significance for realizing the commercial value of the asparagus.

Disclosure of Invention

In order to solve the technical problems, the modified atmosphere packaging method is used for keeping asparagus fresh by adopting different pretreatment combinations, can inhibit the growth of microorganisms, inhibit the asparagus from rotting and deteriorating, reduce the metabolic rate, maintain the nutritional quality and delay the asparagus aging, thereby achieving the purpose of prolonging the storage period and solving the problems that the asparagus is easy to yellow, lignify, mildew and soft rot in the storage process in the prior art.

The invention aims to provide a fresh-keeping method for prolonging the storage period of asparagus, which is to perform modified atmosphere packaging after the asparagus is treated by ultrasonic and antistaling agents.

The second purpose of the invention is to provide a method for improving the nutritional quality of asparagus, which is to perform modified atmosphere packaging after the asparagus is subjected to ultrasonic treatment and 1-methylcyclopropene fumigation.

In one embodiment of the present invention, the ultrasonic power is 100-.

In one embodiment of the invention, the gas component in the modified atmosphere package is O₂5-15% and CO₂Is 5-15%.

In one embodiment of the invention, the preservative is an acetic acid and gibberellin compound preservative or a 1-methylcyclopropene preservative.

In one embodiment of the invention, the concentration of acetic acid in the acetic acid and gibberellin compound preservative is 10-30mL/L, and the concentration of gibberellin is 25-50 mg/L.

In one embodiment of the invention, the mass concentration of the 1-methylcyclopropene is 0.1-1g/5kg of asparagus, i.e. the addition amount of the 1-methylcyclopropene is 0.002% -0.02% of the mass of the asparagus.

In one embodiment of the invention, the method comprises the steps of:

(1) selecting high-grade asparagus with stem length of 25cm, diameter of 16-18mm, no bending, no mechanical damage, no abrasion and no rot;

(2) treating the superior asparagus selected in the step (1) by ultrasonic, immersing the asparagus into an ultrasonic generator containing water, selecting ultrasonic power of 100-;

(3) soaking the asparagus treated in the step (2) in a composite preservative of acetic acid and gibberellin for 5-15min, then taking out and quickly draining;

(4) modified atmosphere packaging the asparagus obtained by the step (3) by using a modified atmosphere packaging machine, and packaging by using a low-density polyethylene antibacterial freshness protection package, wherein the thickness of the low-density polyethylene antibacterial freshness protection package is 2-10mm, and the gas component in the modified atmosphere packaging is O₂5-15% of CO₂5-15% and N₂80-100%;

(5) and (3) refrigerating the asparagus subjected to modified atmosphere packaging, wherein the refrigerating temperature is 2-5 ℃, and the relative humidity is 80-90%.

In one embodiment of the invention, the preservation includes protection from mildew and rot, protection from yellowing, and protection from lignification.

The third purpose of the invention is to provide the application of the method in the aspects of fruit and vegetable fresh-keeping and nutrition quality enhancement.

The invention has the beneficial effects that:

(1) the invention adopts ultrasonic treatment, and the ultrasonic wave can generate cavitation effect, mechanical effect and thermal effect when being transmitted in a liquid medium, thereby achieving the purposes of sterilization, enzyme inactivation and the like. In the aspect of cleaning and sterilizing asparagus, the ultrasonic treatment can effectively remove bacteria, saccharomycetes, moulds and other microorganisms on the surface of the asparagus, thereby effectively inhibiting the growth of the microorganisms on the surface of the asparagus vegetables, preventing the asparagus vegetables from rotting and deteriorating, and prolonging the storage period.

(2) The invention provides a asparagus fresh-keeping method which can be operated in a large scale and has good effect and low cost. According to the method, acetic acid and gibberellin are used as ultrasonic liquid media and act on asparagus in a synergistic manner with ultrasonic treatment, and then modified atmosphere packaging is carried out, so that microorganisms on the surface of the asparagus are effectively killed, and the asparagus rot is delayed.

(3) The invention uses 1-methylcyclopropene to act on asparagus in a synergistic ultrasonic treatment manner, and then modified atmosphere packaging is carried out, so that the respiratory activity of the asparagus is obviously inhibited, the lignification process is delayed, and the storage quality is greatly improved.

(4) The invention uses the modified atmosphere to package the fresh-keeping asparagus, selects proper gas proportion, combines with the ultrasonic and the antistaling agent, has certain synergistic effect, prolongs the fresh-keeping period of the asparagus, prolongs the fresh-keeping period to 40 days, and ensures the freshness and the quality of the asparagus.

Drawings

FIG. 1 is a graph showing the effect of modified atmosphere packaging on the total number of surface colonies during storage of asparagus by combining different pretreatments;

FIG. 2 is a graph showing the effect of different pretreatment combinations on the total number of surface molds and yeasts during storage of asparagus; wherein, CK: a control group; US + MAP: ultrasonic combined air conditioning treatment; AG + MAP: the compound preservative acetic acid and gibberellin are subjected to combined modified atmosphere treatment; US + AG + MAP: the ultrasonic synergistic composite preservative acetic acid and gibberellin are subjected to combined modified atmosphere treatment.

FIG. 3 is a graph of the effect of different pretreatment combinations on the lignin content during storage of asparagus; wherein, CK: a control group; US + MAP: ultrasonic combined air conditioning treatment; 1-MCP + MAP: 1-methylcyclopropene combined modified atmosphere treatment; US +1-MCP + MAP: ultrasonic wave is cooperated with 1-methylcyclopropene for combined modified atmosphere treatment.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of better illustrating the invention and is not intended to limit the invention thereto.

And (4) writing out the total number of surface colonies, the total number of moulds and yeasts, the lignin content and other test methods.

1. Total number of colonies

Reference is made to GB 4789.2-2010.

2. Total number of mold yeasts

Reference is made to GB 4789.15-2016.

3. Lignin content

Drying a proper amount of fresh asparagus in an oven (at 50 ℃ for 10h), homogenizing 0.5g of dry asparagus sample with 80mL of 95% ethanol for 5min, filtering to obtain a residue, and cleaning the residue with 20mL of ethanol. Then dried in an oven (24 h at 50 ℃) to give a dry residue (alcohol-insoluble residue). Transferring the dry residue into a test tube, adding 7.5mL of 2mol/L HCl and 0.5mL of thioglycolic acid, mixing uniformly, reacting with boiling water for 4h, cooling, and centrifuging (7500r, 15min) to obtain the residue. Washing the residue with deionized water, stirring with 10mL0.5mol/L NaOH for 18h, and centrifuging to obtain supernatant.

Then 2mL of HCl is added into the supernatant, and the solution is subjected to complexation precipitation at 4 ℃ for 4h and then centrifuged to obtain the target residue. And finally, adding 10mL of NaOH for dissolution, measuring the absorbance value at 280nm, and drawing a standard curve by using a lignin standard substance.

4. Soluble solid

Refer to NY/T2637-.

Vc content

By 2, 6-dichloroindophenol method, 5g asparagus is weighed and crushed by a mortar, 10mL oxalic acid with the concentration of 20mg/mL is added, and the mixture is ground into pulp. The solution was transferred into a 25mL volumetric flask, and the volume was determined by oxalic acid solution and shaken up. After filtering the sample dilution, 10mL of the filtrate was taken in a 50mL Erlenmeyer flask and titrated with the calibrated 2, 6-dichloroindophenol solution until the solution became pink and did not fade within 15 s.

In the formula: t-mg of Vc content in each 100g of asparagus (mg/100 g);

V₁-volume (mL) of 2, 6-dichloroindophenol solution consumed upon titration of the sample;

V₂-volume (mL) of 2, 6-dichloroindophenol solution consumed upon titration of the sample;

m-mass (g) of sample contained in the filtrate taken at the time of dropping.

6. Chlorophyll content

Weighing 2g of asparagus, grinding the asparagus by using a mortar, redundant 10mL of ethanol-acetone (v/v, 50/50) solution, standing the asparagus for 5h in dark, filtering the solution to obtain supernatant, and measuring the absorbance values of 645nm and 663nm by using an ultraviolet spectrophotometer.

In the formula: v-sample volume (mL);

OD₆₆₃and OD₆₄₅Absorbance values at 663 and 645nm, respectively;

m-asparagus quality (g)