CN103027105A - Fruit wax for fresh-keeping of fruits and vegetables and preparation method and application - Google Patents

Abstract

The invention discloses a fresh-keeping fruit wax for fruits and vegetables and its preparation method and application. A phase inversion emulsification method is adopted, and high-quality oleic acid, myristic acid, morpholine, potassium hydroxide, poly Methyl siloxane, deionized water, choose the emulsification temperature and time suitable for emulsified wax, and the amount and speed of deionized water added, to form an O/W emulsion, and you can obtain composite wax such as oxidized polyethylene and carnauba wax. Fruit and vegetable fresh-keeping fruit wax. The fruit wax synthesized by this method has high film-forming strength. After film formation, not only the gloss is extremely high, which is comparable to imported wax liquid, but also the water retention and air permeability are good. Its excellent performance completely surpasses the current imported high-gloss fruit wax. , in line with food green safety and mechanized waxing requirements. This product can be widely used for waxing citrus, apple, peach, tomato and other fruits and vegetables.

Description

A kind of fresh-keeping fruit wax for fruits and vegetables, its preparation method and application

technical field

The invention belongs to the field of post-harvest fruit and vegetable biotechnology, and specifically relates to a fruit wax for preserving freshness of fruits and vegetables, a preparation method of fruit wax for preserving freshness of fruits and vegetables, and an application of fruit wax for preserving freshness of fruits and vegetables. The freshness preserving wax liquid is suitable for citrus, Apples, peaches, tomatoes and other fruits and vegetables.

Background technique

With the improvement of people's living standards at home and abroad, in order to achieve the freshness of fruits and vegetables and their annual supply, waxing preservation has emerged as a new preservation method. It is artificially smearing a layer of film on the surface of fruits and vegetables. To regulate the pores of the fruit and vegetable skin, reduce the water loss of fruits and vegetables, delay the wilting of fruits and vegetables, limit the gas exchange between fruits and vegetables and the external environment, inhibit the respiratory metabolism of fruits and vegetables, slow down the loss of nutrients and aging, and prolong the storage and shelf life of fruits and vegetables (Bai et al., Alternatives to shellaccoaings provide comparable benefits in terms of gloss, internal gases modification, and quality for 'Delicious' apple fruit. HortSciene 2002, 37: 559-563.); At the same time, it can also increase the gloss of fruits and vegetables and beautify the appearance, thereby increasing the commodity value of fruits and vegetables. As early as the twelfth century, there was a record of "sealing the pedicles with wax" to reduce the water loss of citrus in my country. It was not until the 1930s in the United States that they began to coat citrus and other fruits and vegetables with hot-melted paraffin wax. With a history of more than 70 years, it is widely used in the preservation of citrus, apple, pear, tomato and other fruits and vegetables. Most of the waxes used commercially in the early days were based on paraffin wax and carnauba wax, because paraffin wax controls water loss well, and carnauba wax gives fruit an attractive luster. Now most countries and regions generally use fruit wax, and have their own fruit wax products, such as the Xianliang series fruit wax (211, 402, 402F) of the American DECCO company, the American FMC series fruit wax (Sta-fresh 890HS), Spain FOMESA fruit wax series (Weibao, Weite, Fuxi). This kind of fruit wax can not only meet the health and safety requirements, but also because it contains high shellac resin, it can significantly improve the gloss of fruits and vegetables, and it will soon be used in the United States, China, Spain, Japan, Australia, Israel, South Africa and other countries. The current research on fruit and vegetable waxing treatment in our country is obviously lagging behind developed countries. Although our country has higher and higher requirements for the commercialization of fruits and vegetables, most of the fruit wax used in commercial treatment depends on imports from the United States, Japan, and Spain.

In recent years, many kinds of wax liquids have been developed at home and abroad, but these fruit waxes are mainly high-brightness fruit waxes containing shellac. Although this kind of fruit wax can increase the appearance of fruits and vegetables, make the fruits produce an attractive luster, and reduce the time spent on storage and transportation of fruits and vegetables. The weight loss during the process enhances its competitiveness in the market, but the luster of fruits and vegetables after waxing cannot last long, and the gas permeability of fruits and vegetables after waxing is poor, and anaerobic respiration is easy to occur. Storage at room temperature for 1-2 weeks can lead to ethanol , acetaldehyde, methanol and other volatile odor substances accumulate in large quantities. When the ethanol content is low, it is used as fruit and vegetable aromatic substances, but when the content exceeds 1500 μl/L, the fruits and vegetables are prone to produce peculiar smells such as 'distiller's grains' (Hagenmaier et al., Changes in volatile components of stored tangerines and other specialty citrus fruits with different coatings.J.Food Sci. 2002, 67: 1742-1745). By studying the effects of different waxes on the air permeability and odor content of apples and citrus, it is concluded that oxidized polyethylene wax is better than shellac wax (Hagenmaier, R.D. The flavor of mandarin hybrids with different coatings. Postharvest Biol. Technol. 2002, 24:79-87). Although the gas permeability of oxidized polyethylene wax is slightly better, in many fruit and vegetable varieties, it has poor water retention and low gloss after processing fruits and vegetables, and it will still significantly increase the rate of odorous substances in fruits. Although developed countries have invested a lot of energy in research on improving the gas permeability and gloss of wax liquid, and some new materials have been used in wax liquid modification, this situation has not been effectively changed.

my country is the world's largest fruit and vegetable production and consumption country. In order to improve the competitiveness of the domestic market or export overseas markets of fruits and vegetables, it is urgent to develop high-gloss fruit wax, which has a long-lasting luminosity and can significantly reduce the content of ethanol, acetaldehyde and other odor substances. Shelf life, improve the commodity value of fruits and vegetables.

Contents of the invention

The object of the present invention is to provide a kind of fresh-keeping fruit wax for fruits and vegetables. The fruit wax has selected oxidized polyethylene with good air permeability and carnauba wax with high gloss as the main wax liquid material, and invented a kind of high gloss, which can It is a new type of fruit wax that can reduce the weight loss rate of fruits and vegetables to the greatest extent during the storage and shelf life of fruits and vegetables, has good air permeability, can significantly reduce the accumulation of ethanol, acetaldehyde and other odor substances, and has obvious water and freshness preservation effects.

Another object of the present invention is to provide a preparation method of fruit and vegetable fresh-keeping fruit wax, which adopts the phase transition emulsification method, the method is easy to operate, and the operation is convenient. According to the characteristics of oxidized polyethylene and carnauba wax, high-quality oleic acid and myristic acid are selected. , morpholine, potassium hydroxide, polydimethylsiloxane, deionized water, select the emulsification temperature and time suitable for the emulsified wax, and the amount and speed of deionized water to form an O/W emulsion. Obtain compound fruit and vegetable fresh-keeping fruit waxes such as oxidized polyethylene and carnauba wax. The fruit wax synthesized by this method has high film-forming strength. After film formation, not only the gloss is extremely high, which is comparable to imported wax liquid, but also the water retention and air permeability are good. Its excellent performance completely surpasses the current imported high-gloss fruit wax. , in line with food green safety and mechanized waxing requirements. This product can be widely used for waxing citrus, apple, peach, tomato and other fruits and vegetables.

In order to achieve the above object, the present invention takes the following technical measures:

A fruit and vegetable fresh-keeping fruit wax, which is made of the following raw material mass percentages:

A fruit and vegetable fresh-keeping fruit wax, which is made of the following raw material mass percentages (the preferred range is):

A kind of fresh-keeping fruit wax for fruits and vegetables, which is made of the following raw material weight percentages (best range):

A preparation method for fruit and vegetable fresh-keeping fruit wax, it comprises the steps:

(1) Select and match fresh-keeping fruit wax raw materials: select and match each raw material according to the composition and weight ratio;

(2) Adding raw materials: using phase inversion emulsification method, oxidized polyethylene, carnauba wax, oleic acid, myristic acid, morpholine, potassium hydroxide, polydimethylsiloxane, a small part of deionized water (about 1/3 oxidized polyethylene and carnauba wax weight) raw materials are put into the reactor;

(3) Filler heating and melting: heating and melting at about 120°C, stirring evenly, stirring speed 200-300r/min, stirring emulsification time about 20min, forming W/O emulsion;

(4) Dilute with water: Slowly add hot water above 95°C during the stirring process, after phase inversion to form an O/W emulsion, you can quickly add the remaining hot water, and finally quickly cool down to below 50°C to obtain A fruit and vegetable fresh-keeping fruit wax;

(5) Inspection: inspection according to quality standards;

(6) Metering and packaging: the finished product is sealed and packaged according to the weight to obtain the fruit wax.

The excellent performance of the present invention completely surpasses the current imported high-gloss fruit wax, is even better than other domestic fruit waxes, and meets the requirements of food green safety and mechanized waxing. This product can be widely used for waxing citrus, apple, peach, tomato and other fruits and vegetables. Compared with the prior art, the present invention has the following advantages:

1. Fruit wax is a translucent brown emulsion. After coating, the vegetables are colorless and transparent, with high gloss and long-lasting luminosity;

2. The fruit wax dries quickly and has stable performance, and the fruit surface does not turn white;

3. The viscosity of fruit wax is low, and the mechanical spraying atomization effect is better, more uniform and smoother, preventing the nozzle from being blocked, and at the same time, it is easier to clean the waxing equipment;

4. The hydrophobic substance contained in fruit wax makes it have high water resistance, which can reduce water evaporation and prevent fruits and vegetables from dehydration and wilting;

5. Fruit wax has high air permeability. It is not easy to cause anaerobic respiration during storage. It can significantly reduce the accumulation of ethanol, acetaldehyde and other 'distiller's grains' odorous substances. At the same time, it inhibits the respiration of fruits and vegetables, delays the aging of fruits and vegetables, and prolongs Shelf life of fruits and vegetables.

6. Fruit wax can obviously prevent the browning of fruits and vegetables, keep the fresh color of fruits and vegetables, and continue the economic value of fruits and vegetables;

7. Fruit wax effectively reduces the chance of cross-infection of pathogenic microorganisms, controls the rot rate of fruits and vegetables, and improves the quality of fruits and vegetables.

Detailed ways

Examples 1-11

A fruit wax for preserving freshness, which is prepared from the following raw materials: oxidized polyethylene AC629 (Honeywell, USA), carnauba wax NO3 (Suzhou Yushiji Biotechnology Co., Ltd.), morpholine (BASF, Germany), Oleic acid (Sinopharm Chemical Reagent Co., Ltd.), myristic acid (Tyco Palm Chemicals (Zhangjiagang) Co., Ltd.), polydimethylsiloxane (Changzhou Dow Chemical Co., Ltd.), potassium hydroxide (Sinopharm Chemical Reagent Co., Ltd. company), deionized water.

Unit: mass percentage

A preparation method for fruit and vegetable fresh-keeping fruit wax, it comprises the steps:

(1), select fresh-keeping fruit wax raw materials: select and weigh each component described in any group in Examples 1 to 11;

(2) Adding raw materials: using phase inversion emulsification method, oxidized polyethylene, carnauba wax, oleic acid, myristic acid, morpholine, potassium hydroxide, polydimethylsiloxane, a small part of deionized water (about 1/3 oxidized polyethylene and carnauba wax weight) raw materials are put into the reactor;

(3) Filler heating and melting: heating and melting at about 120°C and stirring evenly, stirring speed 200-300r/min, stirring emulsification time about 20min, forming W/O emulsion;

(4) Dilute with water: Slowly add hot water above 95°C during the stirring process, after phase inversion to form an O/W emulsion, you can quickly add the remaining hot water, and finally quickly cool down to below 50°C to obtain A fruit and vegetable fresh-keeping fruit wax;

(5) Inspection: inspection according to quality standards;

(6) Metering and packaging: the finished product is sealed and packaged according to the weight to obtain the fruit wax.

Example 12:

After the mechanized waxing of the present invention, the glossiness of Satsuma mandarins is comparable to that of the imported wax liquid. After storage for 2 weeks at room temperature at 20°C and 70-75% RH, the weight loss rate is 6.83%; the CO ₂ content inside the fruit is 6.64kPa, O ₂ is 9.29kPa, good air permeability, not easy to cause anaerobic respiration; the content of ethanol is 1707.8μl/L, the content of acetaldehyde is 25.3μl/L, the content of methanol is 24.6μl/L, and the commercial wax Xianliang 402D treatment Wenzhou After tangerine, the weight loss rate was 6.80%, the CO ₂ content inside the fruit was 9.54kPa, the O ₂ content was 4.32kPa; the ethanol content was 3200.3μl/L, the acetaldehyde content was 29.7μl/L, and the methanol content was 31.5μl/L. After being processed, this product has good air permeability when stored at room temperature, has low content of ethanol, acetaldehyde and other odorous substances, and has low distiller's taste, which can significantly prolong the shelf life of Wenzhou citrus.

Example 13

After artificial dipping and waxing of summer oranges in the present invention, after 3 weeks of storage at room temperature at 20°C and 70-75% RH, the weight loss rate is 3.07%, the soluble solids are 11.2%, the titratable acid is 0.55%, and the Vc content is 58.8mg/100g, the ethanol content is 1351.4μl/L, which is significantly lower than 1500μl/L (when the ethanol content is low, it is used as a citrus aromatic substance, and when the content exceeds 1500μl/L, the citrus is prone to produce peculiar smells such as 'distiller's grains'), B The aldehyde content is 16.7μl/L, the methanol content is 80.2μl/L, and the domestically imported commercial wax Xianliang 402D is used to treat summer oranges, the weight loss rate is 5.97%, the soluble solid content is 11.4%, and the titratable acid is 0.62%. , Vc 58.3mg/100g, the ethanol content was 1199.7μl/L after one week, and the content was as high as 7943μl/L after three weeks, the acetaldehyde content was 58.7μl/L and the methanol content was 134.3μl/L. The above results show that after the orange fruit is treated by the present invention, the content of ethanol, acetaldehyde, methanol and other odor substances is lower, and the fruit quality is better. Compared with the control, the shelf life can be significantly extended by about 1 week.

Example 14

After mechanized waxing treatment of Newhall navel oranges, this product has luster, long-lasting luminosity, no whitening, water retention and freshness. It is stored at room temperature 20 ℃, 70-75% RH for 3 weeks. The content of ethanol, acetaldehyde and other odor substances is low. The taste of distiller's grains is low, which can significantly prolong the shelf life of navel oranges. After storage at room temperature for three weeks at 20°C, the weight loss rate was 4.79%, the respiration intensity was 56.62ml CO ₂ ·kg ^-1 ·h ^-1 , the ethanol content was 2879.5μl/L, the acetaldehyde content was 17.9μl/L, and the methanol content The weight loss rate was 5.14%, the respiration intensity was 59.26ml CO ₂ ·kg ^-1 ·h ^-1 , and the ethanol content was as high as 4734.6μl/L. , the acetaldehyde content was 27.3 μl/L, and the methanol content was 90.5 μl/L.

Example 15

After the apples are artificially soaked and waxed by the present invention, the gloss of the apples is high, and the weight loss rate is 6.74% after being stored for 2 weeks at room temperature at 20°C and 70-75%RH; the CO ₂ content inside the fruit is 8.36kPa, and the O ₂ is 8.34 kPa, good air permeability, not easy to cause anaerobic respiration; the content of ethanol is 1528.7μl/L, the content of acetaldehyde is 30μl/L, and the content of methanol is 34.9μl/L. After the apples are treated with commercial wax AppleLustr 221Shellac Based Coating, the weight loss rate The content of CO ₂ inside the fruit is 11.54kPa, O ₂ is 4.32kPa; the content of ethanol is 2444μl/L, the content of acetaldehyde is 29.2μl/L, and the content of methanol is 31.9μl/L. After the apples are processed by this product and stored at room temperature, the content of ethanol, acetaldehyde and other odorous substances is low, and the smell of distiller's grains is low, which can significantly prolong the shelf life of apples.

Example 16

After the tomato is artificially dipped and waxed by the present invention, the gloss of the tomato is high, and after storage for 2 weeks at room temperature at 20°C and 70-75% RH, the weight loss rate is 6.12%, the soluble solid content is 8.8%, and the titratable acid is 0.35%. , the Vc content was 22.3mg/100g, the ethanol content was 1034.5μl/L, the acetaldehyde content was 17.2μl/L, and the methanol content was 22.3μl/L. After the tomato was treated with commercial wax DECCOTomakote 8, the weight loss rate was 6.83%. The solid content is 9.2%, the titratable acid is 0.33%, the Vc content is 19.6mg/100g, the ethanol content is 1430.4μl/L, the acetaldehyde content is 16.4μl/L, and the methanol content is 28.2μl/L. After the tomato is processed by this product and stored at room temperature, the content of ethanol, acetaldehyde and other odor substances is low, and the smell of distiller's grains is low, which can obviously delay the decline of tomato quality.

Claims (4)

1. A fruit and vegetable fresh-keeping fruit wax, which is made of the following raw material mass percentages: Raw material % by mass, % Oxidized polyethylene 5%-20% Carnauba wax 4%-15% Oleic acid 0.5%-5% Myristic acid 0.1%-5% Potassium Hydroxide 0.01%－2% Morpholine 0.5%-5% Polydimethylsiloxane 0.001%－0.01% Deionized water 53%-89%; Described fruit and vegetable fresh-keeping fruit wax, its preparation steps are: (1) Select and match fresh-keeping fruit wax raw materials: select and match each raw material according to the composition and weight ratio; (2) Adding raw materials: oxidized polyethylene, carnauba wax, oleic acid, myristic acid, morpholine, potassium hydroxide, polydimethylsiloxane, 1/3 oxidized polyethylene and The deionized water of carnauba wax weight is dropped in the reactor; (3) The filler is heated and melted: heat and melt at about 120°C and stir evenly, the stirring speed is 200-300 r/min, and the stirring and emulsifying time is about 20 minutes to form a W/O emulsion; (4) Dilute with water: Slowly add hot water above 95°C during the stirring process, after phase inversion to form an O/W emulsion, you can quickly add the remaining hot water, and finally cool down quickly to below 50°C Obtain a fruit and vegetable fresh-keeping fruit wax; (5), inspection: inspection according to quality standards; (6) Metering and packaging: the finished product is sealed and packaged according to the weight to obtain the fruit wax. 2. a kind of fruit and vegetable fresh-keeping fruit wax according to claim 1, it is made of following raw material mass percentage: Raw material % by mass, % Oxidized polyethylene 6%-15% Carnauba wax 4%-12% Oleic acid 1%-4% Myristic acid 0.2%-4% Potassium hydroxide 0.05%-1.5% Morpholine 0.8%-4% Polydimethylsiloxane 0.003%－0.009% Deionized water 60%-86%. 3. a kind of fruit and vegetable fresh-keeping fruit wax according to claim 1, it is made of following raw material mass percentage: Raw material % by mass, % Oxidized polyethylene 8%-10% Carnauba wax 6%-8% Oleic acid 2%-3% Myristic acid 0.5%-2% Potassium hydroxide 0.2%-0.5% Morpholine 1.5%-2% Polydimethylsiloxane 0.006%－0.008% Deionized water 75%-81%. 4. the application of a kind of fruit and vegetable fresh-keeping fruit wax described in claim 1 in fruit and vegetable fresh-keeping.