CN103583675A - Method for maintaining low temperature of postharvest logistic microenvironment of waxberry fruits - Google Patents

Abstract

The invention provides a method for maintaining a suitable low temperature for post-harvest logistics microenvironment of red bayberry fruit. By selecting fruits with uniform size, uniform maturity and no mechanical damage, they are placed in a cold storage for low temperature pre-cooling, and temperature control materials are placed at -20°C. Freeze for more than 24 hours, put the bayberry fruit into the foam box for logistics, and then put it into the temperature control material to maintain the low temperature. The foam box is sealed and then transported. The invention can effectively maintain the relatively low logistics temperature of the harvested red bayberry fruit, delay the aging process, reduce the microbial activity on the fruit surface, reduce fruit rot, and better maintain the commercial quality of the fruit. At the same time, transporting bayberry fruit through the present invention can reduce the transport cost by reducing the weight of the cold storage agent, especially the transport cost of long-distance air transport, and at the same time, it can solve the problem of increasing the humidity of the logistics microenvironment due to the damage of the ice bag during the use of ordinary ice cubes , reduce bayberry fruit rot. The present invention can also be applied to other horticultural products such as non-peel coatings and perishable fruits.

Description

A method for maintaining low temperature in microenvironment of postharvest logistics of red bayberry fruit

technical field

The invention belongs to fruit storage and transportation, and relates to a method for maintaining a suitable low temperature in the post-harvest logistics microenvironment of bayberry fruit. the

Background technique

In the process of fruit sealing and logistics, the microenvironment temperature of the sealing is often too high due to high external temperature and vigorous respiration of the fruit itself, resulting in abnormal respiration and metabolism of the fruit, especially for fruits with high water content, abnormal microbial activity on the surface, and accelerated fruit ripening and aging. The fruit rots, the quality deteriorates, and it is difficult to maintain the normal quality and commerciality of the fruit. Appropriate low temperature conditions are an effective way to maintain commerciality in the logistics process of horticultural products. In the past, the method of using ordinary ice cubes can maintain a suitable low temperature, but problems such as rot caused by high humidity and excessive transportation costs caused by the large amount of ordinary ice cubes have caused excessive rot loss and quality decline in the logistics process of red bayberry fruit, making it difficult to achieve The economic benefits in the logistics process and the limitation of the logistics radius also greatly limit the large-scale development of the red bayberry industry. Biological ice packs are a new type of freezing medium. There is no water pollution when thawing and thawing, and they can be used repeatedly. The price is low, and their effective cold capacity is 3-6 times that of ordinary ice cubes of the same volume. Because of its large cold capacity, odorless, non-toxic high polymer compound as the basic composition of raw materials, its content is crystal clear, non-reflective, non-corrosive, and flexible, biological ice packs can replace ice cubes, dry ice, etc. and can be widely used in reagents , food, microbiology, industry, animal husbandry, fishery, storage and transportation of precision instruments, and other freezing media that require cold sources. Common biological ice packs are divided into three types: high, medium and low temperature (phase transition temperatures are: 6°C, 0°C; and -18°C). The use of biological ice packs for the cold chain logistics of perishable special fruits such as red bayberry, while maintaining a low temperature in the microenvironment, will not cause excessive humidity due to melting, which can prolong the storage and logistics preservation time and expand the logistics radius. It is an effective A new method for microenvironmental temperature control of specialty perishable fruit logistics. the

Contents of the invention

The purpose of the present invention is to provide a method for maintaining the low temperature of the post-harvest logistics microenvironment of red bayberry fruit, which is achieved by the following steps: (1) selecting fruits with uniform size, uniform maturity, and no mechanical damage; (2) placing them in cold storage at low temperature Pre-cooling to release field heat to effectively reduce respiratory consumption and maintain good product quality; (3) Put the temperature control material (the biological ice pack with a phase transition temperature of 0°C in this invention) into -20°C for freezing More than 24 hours; (4) Put the bayberry fruit into the foam box for logistics, and then put it into the temperature control material to maintain the low temperature; (5) Logistics transport after the foam box is sealed. the

The low-temperature pre-cooling temperature in step (2) is 2-3°C, and the pre-cooling time is more than 3-12 hours. the

The temperature control material in steps (3) and (4) is a biological ice pack with a phase transition temperature of 0°C. the

Step (4) The usage of biological ice packs is as follows: In order to ensure the uniformity of temperature in the logistics foam box, the biological ice packs are placed in the middle and at both ends of the foam box respectively, and the packaging size of the biological ice packs should be 50 or 100 g as much as possible. the

The consumption of biological ice pack is: the consumption of biological ice pack decides according to the weight of bayberry fruit and the volume of foam box. Packed in a foam box of 2 kg bayberry fruit (volume about 7 liters), put 150-200 g of biological ice packs into it; pack 2.5-3 kg of bayberry fruit in a foam box (volume of about 10 liters), put 250-300 g of biological ice packs into it. Ice packs; packaged as 9-12 kg bayberry fruit foam box (volume about 20 liters), put 400-500 g biological ice packs. By analogy, determine the amount of biological freezing point according to the volume of the foam box and the amount of fruit. the

Step (5) The temperature outside the foam box in the logistics process is room temperature (25°C). the

The present invention can also be applied to other horticultural products such as non-peel coatings and perishable fruits. the

The invention includes the steps of screening biological ice bag materials, biological ice bag dosage, use operation, packaging, transportation and the like in the logistics process of bayberry postharvest. It solves the problems of fruit rot, peculiar smell, and quality decline caused by excessive respiratory metabolism of the fruit and abnormal microbial activity on the surface caused by excessive temperature in the logistics process of bayberry fruit, and solves the problems caused by the use of ordinary ice cubes in the past The humidity in the micro-environment of the logistics is too high, which leads to the problem of rot and quality decline of the bayberry fruit, and at the same time solves the problem of high transportation costs caused by the excessive volume and weight of ordinary ice cubes used in the logistics process of bayberry air transport. The invention has the advantages of less consumption of biological ice packs, good effect of maintaining low temperature, relatively low humidity in micro-environment, good commerciality of logistics fruits, relatively low transportation cost and the like. the

The invention can effectively maintain the relatively low logistics temperature of the harvested red bayberry fruit, delay the aging process, reduce the microbial activity on the fruit surface, reduce fruit rot, and better maintain the commercial quality of the fruit. At the same time, transporting bayberry fruit through the present invention can reduce the transport cost by reducing the weight of the cold storage agent, especially the transport cost of long-distance air transport, and at the same time, it can solve the problem of increasing the humidity of the logistics microenvironment due to the damage of the ice bag during the use of ordinary ice cubes , reduce bayberry fruit rot. the

Description of drawings

Figure 1 is a curve diagram of temperature and humidity changes in the microenvironment in the foam box during the logistics process of bayberry fruit. the

Detailed ways

The present invention will be further described in conjunction with implementation examples. the

Embodiment one

(1) Select red bayberry fruits with uniform size, consistent maturity, and no mechanical damage; (2) Put them in the cold storage at 2-3°C, pre-cool for 3-12 hours, and release the heat in the field to effectively reduce respiratory consumption and maintain good quality. (3) Put the temperature control materials (ordinary ice cubes and biological ice packs) into -20°C for more than 24 hours to freeze; (4) Divide the pre-cooled red bayberry fruits into 4 groups and put them into logistics with the same specification The foam incubator is put into the temperature control material to maintain the low temperature. The temperature control material is biological ice packs with different phase transition temperatures. Among the four groups of fruits, one group was added with the same amount of ordinary ice cubes, and the other three groups were respectively added with three kinds of biological ice packs with different phase transition temperatures. The phase transition temperature is 0°C; the phase transition temperature of biological ice pack c is -18°C. (5) Sealed packaging, logistics at room temperature (25°C) for 20-25 hours, real-time recording of the temperature and humidity of the microenvironment in the box during transportation. (6) After the logistics process is over, take out the fruit and put it on the shelf, and count the rot rate, white spot index, etc. after the fruit logistics is over and 1 day and 2 days after the shelf.

Step (4) The usage of biological ice packs is as follows: place the biological ice packs in the middle and both ends of the foam box respectively. the

Step (4) The amount of biological ice packs is: the amount of biological ice packs depends on the weight of the bayberry fruit and the volume of the foam box. Packed in a foam box of 2 kg bayberry fruit (volume about 7 liters), put 150-200 g of biological ice packs into it; pack 2.5-3 kg of bayberry fruit in a foam box (volume of about 10 liters), put 250-300 g of biological ice packs into it. Ice packs; packaged as 9-12 kg bayberry fruit foam box (volume about 20 liters), put 400-500 g biological ice packs. By analogy, determine the amount of biological freezing point according to the volume of the foam box and the amount of fruit. the

Step (5) Use a wired temperature and humidity recorder to detect the temperature and humidity of the microenvironment in the foam box during the logistics process, and record the whole process. After the completion, take out the temperature and humidity data and download them to the computer for comparison. the

Step (6) The statistical method of the rot rate is: the number of rotten fruits accounts for the percentage of the total number of statistical fruits, and the statistics of rotten fruits are accumulated; the statistical method of the white spot index: no white spot is 0 grade, and the white spot area is ≤10 % is grade 1, white spot area > 10% is grade 2, and the inspection results are calculated according to the following formula to calculate the fruit white spot index: index = ∑ (level) × (number of fruits in each level) / (highest number × total number of inspected fruits ). the

Embodiment two

Biological ice packs with different phase transition temperatures have certain differences in cold storage capacity and cold release rate. The results show that the common temperature change is similar to the temperature change of the three kinds of biological ice packs, and the whole process is slightly higher than that of the biological ice packs. However, the amount of ordinary ice cubes in this process is 3 times that of the biological ice packs, and the ambient humidity in the box using ice cubes In the later stage, it is always higher than the three kinds of biological ice packs (the relative humidity is too high, which leads to abnormal respiratory metabolism, white spots of fruit, rot, etc., which are not conducive to the storage and transportation of bayberry fruit). Biological ice pack a can maintain a relatively lower temperature than biological ice pack b within the first 6 hours, and has been maintained at an ambient temperature lower than 5°C, while biological ice pack b is around 5-8°C, but as time goes by Prolonged, the temperature maintained by biological ice pack a rises rapidly, and after 10 hours it is already higher than 8°C, while biological ice pack b can still maintain the original temperature, especially after 20 hours or so, the temperature of biological ice pack a is close to 20°C while the biological The temperature of ice pack b is about 16°C, which is relatively stable. It can be seen that the freezing point of biological ice pack a is lower than that of biological ice pack b, and the cooling capacity is released faster, but the cold storage capacity is better than that of biological ice pack b. The biological ice pack c can maintain a low temperature of 2-3°C in the first 7 hours or so, but the temperature rises rapidly in the later period, especially when it is close to the room temperature outside the foam box at 20 hours, which is not conducive to maintaining low temperature for a long time. It can be seen that in terms of temperature and humidity maintenance, the effect of biological ice pack b is the best (Figure 1).

Embodiment three

Due to the biological characteristics of red bayberry fruit, temperature and humidity have a great influence on its rot rate during storage and logistics, and higher temperature and higher humidity can easily cause fruit rot. The results show that because the biological ice pack 2 can effectively control the temperature of the microenvironment of the bayberry fruit logistics at a low level, and will not cause excessive humidity in the microenvironment like ordinary ice cubes, the logistics bayberry fruit under the condition of this biological ice pack will rot The rot rate was the lowest, and the rot rate after 2 days on the shelf was only 6.4%. Compared with ordinary ice, biological ice packs 1 and 3 also reduced the fruit rot rate to a certain extent, which were 7.9% and 7.6% respectively; The rot was the worst and could reach 13.5% after two days on the shelf (Table 1).

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Embodiment Four

The occurrence of white spots is one of the important indicators of the quality deterioration of bayberry fruit during storage and logistics. The occurrence of white spots on red bayberry fruit is due to the fact that red bayberry fruit has no pericarp coating, a small amount of juice flowing out of the fruit due to slight mechanical injury or a small amount of water droplets accumulated on the surface of the fruit due to excessive environmental humidity, which eventually leads to the dissolution, loss and discoloration of anthocyanins on the surface of red bayberry fruit, resulting in White spots, the spots will be further dented and eventually rot will occur. The results show that among the four temperature control methods, the white spot index of biological ice pack 2 is the lowest, and the white spot index is 0.28 after 2 days of storage; the treatment with the highest white spot index is logistics bayberry fruit that is controlled by ordinary ice cubes, and reaches 0.43 after two days of storage , Bio-ice packs 1 and 3 had little difference, 0.34 and 0.32, respectively (Table 2).

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Claims (6)

1. maintain Waxberry fruit and adopt a method for rear logistics microenvironment low temperature, it is characterized in that, by following steps, realize: (1) selects the fruit that size is even, maturity is consistent, have no mechanical damage; (2) put into the precooling of freezer low temperature, discharge field heat, effectively to reduce respiration consumption, maintain good product quality; (3) temperature control material is put at-20 ℃ freezing more than 24 hours; (4) Waxberry fruit is put into logistics bubble chamber, then puts into temperature control material and maintain low temperature; (5) logistics transportation after bubble chamber sealing.

2. a kind of method that Waxberry fruit is adopted rear logistics microenvironment low temperature that maintains according to claim 1, is characterized in that, the low temperature precooling temperature in step (2) is 2-3 ℃, pre-more than cool time 3-12 hour.

3. a kind of method that Waxberry fruit is adopted rear logistics microenvironment low temperature that maintains according to claim 1, is characterized in that, step (3) and (4) described temperature control material are that phase transition temperature is the biological ice bag of 0 ℃.

4. a kind of method that Waxberry fruit is adopted rear logistics microenvironment low temperature that maintains according to claim 1, it is characterized in that, the side's of making usage of the biological ice bag of step (4) is: biological ice bag is placed on respectively in the middle of bubble chamber and two ends, and the size of biological ice bag packing adopts the packing of 50 or 100 g.

5. a kind of method that Waxberry fruit is adopted rear logistics microenvironment low temperature that maintains according to claim 1, it is characterized in that, the consumption of biological ice bag is: the consumption of biological ice bag is determined according to the volume of the weight of Waxberry fruit and bubble chamber, be packaged as the bubble chamber of 2 kilograms of Waxberry fruits, put into the biological ice bag of 150-200 g; Be packaged as the bubble chamber of 2.5-3 kilogram of Waxberry fruit, put into the biological ice bag of 250-300 g; Be packaged as the bubble chamber of 9-12 kilogram of Waxberry fruit, put into the biological ice bag of 400-500 g.

6. a kind of method that Waxberry fruit is adopted rear logistics microenvironment low temperature that maintains according to claim 1, is characterized in that, the temperature of step (5) logistics progress bubble chamber outside is room temperature.