Tremella aurantialba sourced fruit and vegetable fresh-keeping agent as well as preparation method and application thereof

Abstract

The invention provides a tremella aurantialba sourced fruit and vegetable fresh-keeping agent as well as a preparation method and application thereof, and belongs to the technical field of fruit and vegetable fresh-keeping agents. In the invention, the tremella aurantialba sporocarp is subjected to ultrasonic extraction with water, and then alcohol precipitation and drying are performed to obtain the tremella aurantialba-derived fruit and vegetable fresh-keeping agent disclosed by the invention. When fruits and vegetables are soaked in an aqueous solution of the tremella aurantialba sourced fruit and vegetable preservative, the preservation time and the storage period of the fruits and vegetables can be prolonged, the loss rate is reduced, the shelf life of the fruits and vegetables is prolonged, and economic benefits are improved. The fruit and vegetable fresh-keeping agent has the advantages of easily available raw materials, simple preparation method, natural components and no chemical residue, accords with the concept of green and pollution-free, and is suitable for large-scale popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of fruit and vegetable preservatives, and in particular to a golden ear source fruit and vegetable preservative, and a preparation method and application thereof. Background Art

[0002] Fruits and vegetables contain a variety of nutrients needed for human life, but the production of fruits and vegetables is highly seasonal and regional, and fruits and vegetables themselves are perishable, which contradicts the urgency of consumers for the diversity of fruits and vegetables and off-season regulation. Therefore, maintaining the natural quality and characteristics of fruits and vegetables as long as possible has become an important issue in the food field. At present, the preservation methods used in the field of fruit and vegetable preservation mainly include physical, chemical and biological methods. The physical methods mainly include: low temperature storage, gas storage, reduced pressure storage, electromagnetic radiation storage, etc. Among them, the more advanced preservation technologies mainly include critical low temperature and high humidity preservation, intercellular water structured gas storage, ozone gas storage, etc. Although these preservation methods are widely used, they require special environmental equipment, complex operation and high cost; chemical methods mainly preserve fruits through fruit preservatives. The use of preservatives is to inhibit the respiration of fruits, control the speed of fruit aging, and control the growth of microorganisms in fruits through antiseptic and sterilization methods. In addition, maintaining relative humidity is also an important measure for fruit preservation to avoid internal water evaporation. Chemical fruit preservatives include preservatives, ethylene removers, coating preservatives, gas generators, gas regulators, humidity regulators and physiological activity regulators, etc. However, long-term consumption of fruits treated with chemical fruit preservatives will have a negative impact on the human body. Therefore, the development of natural preservatives for the preservation of fruits and vegetables will be the future development direction.

[0003] Tremella aurantialba is a fungus of the family Tremella, also known as yellow fungus, golden white fungus, yellow fungus, and brain fungus. Tremella contains rich polysaccharides, protein, and trace elements such as phosphorus, sulfur, manganese, iron, magnesium, calcium, and potassium. It is a nutritional tonic and can be used as a medicine. It is warm in nature with a cold taste, sweet in taste, can resolve phlegm, relieve cough, calm asthma, regulate qi, soothe the liver and intestines, and is mainly used to treat lung heat, excessive phlegm, cold cough, asthma, hypertension and other diseases. However, there is no report on the use of Tremella extract to prepare a preservative. Summary of the invention

[0004] The purpose of the present invention is to provide a golden ear source fruit and vegetable preservative and a preparation method and application thereof, so as to solve the problem of harmful residues of chemical fruit and vegetable preservatives.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a golden ear source fruit and vegetable preservative, comprising the following steps:

[0007] S1. Mix the Tremella fuciformis fruiting body with water, extract at 50-70° C. for 20-30 min, and obtain a Tremella fuciformis extract;

[0008] S2. The Tremella extract is concentrated to 25 to 33% of the original volume to obtain a Tremella extract concentrate;

[0009] S3. The Tremella fuciformis extract concentrate was mixed with an ethanol solution, allowed to stand, centrifuged, and the precipitate was collected;

[0010] S4. washing and drying the precipitate to obtain the golden ear source preservative.

[0011] Preferably, the mass volume ratio of the Tremella fuciformis fruiting body to water is 1g:15-20mL.

[0012] Preferably, the extraction is accompanied by ultrasound, and the frequency of the ultrasound is 400-500W.

[0013] Preferably, the concentration is rotary evaporation concentration, the rotation speed of the rotary evaporation is 140-160 rpm, and the temperature of the rotary evaporation is 50-70°C.

[0014] Preferably, the volume fraction of the ethanol solution is 90-95%, the volume fraction of the ethanol solution is 90-95%, and the volume ratio of the Tremella fuciformis extract concentrated solution to the ethanol solution is 1:2-3.

[0015] Preferably, the centrifugal speed is 4000-5000 rpm, and the centrifugal time is 10-15 min.

[0016] Preferably, the Tremella fuciformis fruiting bodies are cut into particles with a size of 0.5 to 2 cm before extraction.

[0017] Preferably, the drying temperature is 50-60° C., and the drying time is 2.5-3.5 hours.

[0018] The invention also provides a golden ear source fruit and vegetable preservative obtained by the preparation method.

[0019] The present invention also provides a method for preserving fruits and vegetables. The golden ear source fruit and vegetable preservative is dissolved in water and then the fruits and vegetables are soaked for 2 to 3 minutes. The mass volume ratio of the golden ear source fruit and vegetable preservative and water is 1g:50 to 100mL.

[0020] By adopting the above technical scheme, the present invention has the following beneficial effects: the golden ear source fruit and vegetable preservative prepared by the present invention is rich in polysaccharides, has antibacterial and antioxidant effects, and the edible film formed on the surface of fruits and vegetables can inhibit respiration, reduce water loss, and thus achieve the effect of preservation. Soaking fruits and vegetables in an aqueous solution of the golden ear source fruit and vegetable preservative of the present invention can extend the fresh-keeping time and storage period of fruits and vegetables, reduce the loss rate, and thus extend the shelf life of fruits and vegetables, and improve economic benefits. The raw materials of the fruit and vegetable preservative of the present invention are easy to obtain, the preparation method is simple, and the fruit and vegetable preservative of the present invention is a natural ingredient without chemical residues, which conforms to the concept of "green and pollution-free", and is suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the freshness of strawberries on the first day of storage. The left is the control, and the right is the strawberries using the preservative of Example 1.

[0022] Figure 2 This is the freshness of strawberries on the third day of storage. The left is the control, and the right is the strawberries using the preservative of Example 1.

[0023] Figure 3 This is the freshness of strawberries on the fourth day of storage. The left is the control, and the right is the strawberries using the preservative of Example 1.

[0024] Figure 4 This is the freshness of strawberries on the fifth day of storage. The left is the control, and the right is the strawberries using the preservative of Example 1.

[0025] Figure 5 This is the freshness of mangoes on the fifth day of storage. The left is the control, and the right is the mangoes using the preservative of Example 1.

[0026] Figure 6 The freshness of bananas on the fifth day of storage. The left is the control, and the right is the bananas treated with the preservative of Example 1. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing a golden ear source fruit and vegetable preservative, comprising the following steps:

[0028] S1. Mix the Tremella fuciformis fruiting body with water, extract at 80-100° C. for 20-30 min, and obtain a Tremella fuciformis extract;

[0029] S2. The Tremella fuciformis extract is concentrated to 25 to 33% of the original volume to obtain a Tremella fuciformis extract concentrate;

[0030] S3. The Tremella fuciformis extract concentrate was mixed with an ethanol solution, allowed to stand, centrifuged, and the precipitate was collected;

[0031] S4. washing and drying the precipitate to obtain the golden ear source preservative.

[0032] The invention first cuts the golden ear fruiting bodies into blocks, wherein the particle size of the blocks is 0.5-2 cm, more preferably 0.8-1.7 cm, and more preferably 1.3 cm; then the cut golden ear fruiting bodies are mixed with water for extraction; the mass volume ratio of the golden ear fruiting bodies to water is 1 g:15-20 mL, more preferably 1 g:16-18 mL, and more preferably 1 g:17 mL; the extraction temperature is 50-70° C., more preferably 55-66° C., and more preferably 60° C.; the extraction time is 30-60 min, more preferably 40-50 min, and more preferably 45 min; the extraction is ultrasonic extraction, the ultrasonic power is 400-500 W, more preferably 430-480 W, and more preferably 450 W, the extraction is repeated 1-2 times, and the extracts are combined to obtain the golden ear extract.

[0033] The present invention concentrates the Tremella fuciformis extract to obtain a Tremella fuciformis extract concentrate; the concentrate is concentrated to 25-33% of the original volume, more preferably to 27-31%, and more preferably to 30%; the concentration is rotary evaporation concentration, the rotation speed of the rotary evaporation concentration is 140-160rpm, more preferably to 145-155rpm, and more preferably to 150rpm; the temperature of the rotary evaporation concentration is 50-70°C, more preferably to 65-65°C, and more preferably to 60°C.

[0034] The present invention mixes the Tremella fuciformis extract concentrate with an ethanol solution, allows the mixture to stand, performs centrifugation, and collects precipitates; the volume fraction of the ethanol is 90-95%, more preferably 91-93%, and more preferably 92%; the volume ratio of the Tremella fuciformis extract concentrate to the ethanol solution is 1:2-3, more preferably 1:2.2-2.8, and more preferably 1:2.5; the mixture is allowed to stand for 8-12 hours, more preferably 9-11 hours, and more preferably 10 hours; the mixture is centrifuged after standing, the rotation speed of the centrifuge is 4000-5000 rpm, more preferably 4200-4800 rpm, and more preferably 4500 rpm; the centrifugation time is 10-15 minutes, more preferably 12-14 minutes, and more preferably 13 minutes; and the precipitate is collected after centrifugation.

[0035] The precipitate is washed 2 to 3 times and then dried. The washing is preferably carried out with distilled water. The drying temperature is 50 to 60° C., more preferably 52 to 58° C., and more preferably 55° C.; the drying time is 2.5 to 3.5 h, more preferably 3 h, to obtain the golden ear source preservative.

[0036] The present invention also provides a golden ear source fruit and vegetable preservative prepared according to the preparation method.

[0037] The present invention also provides a preservation method, wherein the golden ear source fruit and vegetable preservative is dissolved in water, and then the fruits and vegetables are soaked for 2 to 3 minutes, preferably 2.2 to 2.8 minutes, and more preferably 2.5 minutes; the mass volume ratio of the golden ear source fruit and vegetable preservative and water is 1g:50 to 100mL, preferably 1g:70 to 90mL, and more preferably 1g:80mL.

[0038] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0039] Example 1

[0040] Cut 20g of Tremella fuciformis fruiting bodies into small pieces of 0.5-2cm and mix with water at a solid-liquid ratio of 1g:15mL, extract for 30min at 70℃ and 400W ultrasonic conditions, extract 3 times in total, combine the extracts to obtain Tremella fuciformis extract. Concentrate the Tremella fuciformis extract to 33% of the original volume by rotary evaporation at 60℃ and 140rpm to obtain Tremella fuciformis extract concentrate. Mix the Tremella fuciformis extract concentrate with 95% ethanol by volume in a volume ratio of 1:2, let stand for 8h, centrifuge at 4000rpm for 15min, and collect the precipitate. Wash the precipitate with distilled water 3 times, dry it at 50℃ for 3.5h, and obtain the Tremella fuciformis source preservative.

[0041] Example 2

[0042] Cut 20g of Tremella fuciformis fruiting bodies into small pieces of 0.5-2cm and mix with water at a solid-liquid ratio of 1g:18mL, extract at 60℃, 450W ultrasonic conditions for 40min, extract 3 times in total, combine the extracts to obtain Tremella fuciformis extract. Concentrate the Tremella fuciformis extract to 30% of the original volume by rotary evaporation at 50℃, 150rpm to obtain Tremella fuciformis extract concentrate. Mix the Tremella fuciformis extract concentrate with 93% ethanol by volume at a volume ratio of 1:2.5, let stand for 10h, centrifuge at 4500rpm for 12min, and collect the precipitate. Wash the precipitate with distilled water 3 times, dry it at 55℃ for 3h, and obtain Tremella fuciformis source preservative.

[0043] Example 3

[0044] Cut 20g of Tremella fuciformis fruiting bodies into small pieces of 0.5-2cm and mix with water at a solid-liquid ratio of 1g:20mL, extract for 50min at 50°C and 500W ultrasonic conditions, extract 3 times in total, combine the extracts to obtain Tremella fuciformis extract. Concentrate the Tremella fuciformis extract to 25% of the original volume by rotary evaporation at 70°C and 160rpm to obtain Tremella fuciformis extract concentrate. Mix the Tremella fuciformis extract concentrate with 90% ethanol by volume in a volume ratio of 1:3, let stand for 12h, centrifuge at 5000rpm for 10min, and collect the precipitate. Wash the precipitate with distilled water 3 times, dry it at 60°C for 2.5h, and obtain a Tremella fuciformis source preservative.

[0045] Comparative Example 1

[0046] Different from Example 1, the extraction temperature is 40°C.

[0047] Comparative Example 2

[0048] The difference from Example 1 is that the ultrasonic power is 300W.

[0049] Comparative Example 3

[0050] The difference from Example 1 is that anhydrous ethanol is used for alcohol precipitation.

[0051] Comparative Example 4

[0052] The difference from Example 1 is that 80% by volume ethanol is used for alcohol precipitation.

[0053] Experimental Example 1

[0054] Weigh 0.1g of the above polysaccharide sample and dissolve it in distilled water and make up to 10mL. Accurately pipette 500μL of the above polysaccharide sample solution into a colorimetric tube, add water to 2.0mL, then add 1.0mL of 5% phenol solution, mix well, then add 10.0mL of concentrated sulfuric acid on an ice bath, mix well, heat in a boiling water bath for 20min, take out and cool to room temperature, and measure the absorbance at a wavelength of 485nm using a UV-visible spectrophotometer. The concentration of the polysaccharide in the sample solution to be tested is C (mg / mL); V is the volume of the sample solution to be tested (mL); n is the dilution multiple of the sample solution; m is the mass of the Tremella fuciformis raw material (g), and the yield of each group of polysaccharides is calculated. The results are shown in Table 1.

[0055]

[0056] Table 1 Polysaccharide yield of each treatment group

[0057] Treatment Group Tremella fuciformis polysaccharide yield (%) Example 1 11.3 Example 2 10.9 Example 3 12.1 Comparative Example 1 7.5 Comparative Example 2 7.2 Comparative Example 3 8.1 Comparative Example 4 6.9

[0058] As can be seen from Table 1, the yields of Tremella fuciformis polysaccharides in Examples 1 to 3 of the present invention are higher than those in the comparative example, indicating that the extraction temperature, ultrasonic frequency and the concentration of ethanol used for alcohol precipitation of the present invention are beneficial to improving the yield of Tremella fuciformis polysaccharides.

[0059] Experimental Example 1

[0060] Select fresh, ripe, uniform strawberries, mangoes and bananas, and remove those with diseases and mechanical damage for the experiment. Divide the above-screened fruits into 8 groups, each group has 50 strawberries, 50 mangoes and 50 bananas. Dissolve 30g of the golden ear source fresh-keeping prepared in Examples 1 to 3 and Comparative Examples 1 to 4 in 3L of water, and soak the fruits for 3 minutes; the fruits soaked in distilled water are used as controls. After the moisture on the surface of the fruit is naturally dried, observe the changes in the fruit every day, and count the freshness of each group of fruits. The results are shown in Tables 2 to 4 and Figures 1 to 6 shown.

[0061] Strawberry freshness classification standards:

[0062] Grade 1: The fruit is fresh and full, without any signs of shrinkage or rot;

[0063] Level 2: The fruit is shrunken but not rotten or deteriorated;

[0064] Level 3: The fruit has mold spots, rots and deteriorates.

[0065] Table 2 Preservative effect on strawberry

[0066]

[0067]

[0068] Mango freshness classification standards: Level 1: The fruit is fresh and plump, without any peeling or rot; Level 2: The peeling of the fruit is ≤30%, and there is no rot; Level 3: The peeling of the fruit is >30% or there is rot.

[0069] Table 3 Preservative effect on mango

[0070]

[0071]

[0072] Banana freshness classification standards:

[0073] Grade 1: The fruit is fresh and full, without black skin or rot;

[0074] Level 2: The fruit skin is ≤50% black, and there is no rot or deterioration;

[0075] Level 3: The black skin of the fruit is greater than 50% or it is rotten and deteriorated.

[0076] Table 4 Preservative effect on banana

[0077]

[0078] It can be seen from Tables 2 to 4 that after the preservative of the present invention is used to soak the fruit, the shelf life of the fruit is significantly increased, and the preservation effect is better than that of Comparative Examples 1 to 4, indicating that the extraction temperature, ultrasonic frequency and volume fraction of ethanol can affect the preservation effect of the preservative. The preservative prepared under the preparation conditions of the present invention can increase the proportion of fruits with a first-level freshness, prolong the time for fruit shrinkage and decay, and has a good preservation effect.

[0079] From the above examples, it can be seen that the present invention provides a golden ear source fruit and vegetable preservative and its preparation method and application. After soaking fruits in the golden ear source fruit and vegetable preservative aqueous solution prepared by the present invention, the preservation time of fruits and vegetables can be effectively extended, and it is green and pollution-free.

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a golden ear source fruit and vegetable preservative, characterized in that: The following steps are involved: S1. Mix the Tremella fuciformis fruiting body with water, extract at 50-70° C. for 20-30 min, and obtain a Tremella fuciformis extract; S2. The Tremella extract is concentrated to 25 to 33% of the original volume to obtain a Tremella extract concentrate; S3. The Tremella fuciformis extract concentrate was mixed with an ethanol solution, allowed to stand, centrifuged, and the precipitate was collected; S4. washing and drying the precipitate to obtain the golden ear source preservative.

2. The preparation method according to claim 1, characterized in that: The mass volume ratio of the Tremella fuciformis fruiting body to water is 1g:15-20mL.

3. The preparation method according to claim 2, characterized in that: The extraction is accompanied by ultrasound, and the frequency of the ultrasound is 400-500W.

4. The preparation method according to claim 3, characterized in that: The concentration is rotary evaporation concentration, the rotation speed of the rotary evaporation is 140-160 rpm, and the temperature of the rotary evaporation is 50-70°C.

5. The preparation method according to claim 4, characterized in that: The volume fraction of the ethanol solution is 90-95%, and the volume ratio of the Tremella fuciformis extract concentrated solution to the ethanol solution is 1:2-3.

6. The preparation method according to claim 5, characterized in that: The centrifugal speed is 4000-5000 rpm, and the centrifugal time is 10-15 min.

7. The preparation method according to claim 6, characterized in that: Before extraction, the Tremella truncatula fruiting bodies were cut into particles with a size of 0.5 to 2 cm.

8. The preparation method according to claim 7, characterized in that: The drying temperature is 50-60° C., and the drying time is 2.5-3.5 hours.

9. The golden ear source fruit and vegetable preservative obtained by the preparation method according to any one of claims 1 to 8.

10. A method for preserving fruits and vegetables, characterized in that: After the golden ear source fruit and vegetable preservative according to claim 9 is dissolved in water, the fruits and vegetables are soaked for 2 to 3 minutes; the mass volume ratio of the golden ear source fruit and vegetable preservative mixed with water is 1g:50 to 100mL.

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