Nanguo Northern Transport Point and Transport Freshness Technology
2024-11-07 14:01:29
I. General situation The concept of China's Nanguo Beiyun refers to the fruit grown and sold in the tropical and subtropical evergreen trees in the south. It is transported to all parts of the north and is called Nanguo Beiyun. As for some deciduous fruit trees in the southern provinces, such as pears, persimmons, kiwifruit, and pomegranates, they are not included. According to incomplete statistics, the total amount of Nanguo Beiyun in recent years is about 6.6 million tons each year. Among them, there were 5.18 million tons of oranges, 830,000 tons of bananas, 298,000 tons of litchi, 170,000 tons of pineapples, 49,000 tons of mangoes, 210,000 tons of longan, 14,000 tons of batches, and papayas. 10,000 tons, 990,000 tons of foreign peaches and 0.12 million tons of Yangmei. The transportation and circulation of fruits is an indispensable part of the fruit industry chain. With the rapid increase of fruit production in our country and the continuous development of domestic and foreign markets, Nanguo Beiyun, North Fruit Nanyang go abroad, and circulate in the international market. The long-distance transportation of fruit products has become more prominent and more important. Nanguo Beiyun is another major component of long-distance transportation of fruit. Whether it is Nanguobeiyun or Nanguonanyun, it must be subject to some basic conditions. Otherwise, it is difficult to achieve the goal. However, the fruits produced by the southern evergreen fruit tree must be fruits grown under specific phenotypic conditions in the tropics and subtropics. The botany and postharvest physiology of the fruits are very different from those of the northern fruits. Therefore, when carrying out the Nanguo North Transportation, we must pay attention to the basic conditions for the long-distance transportation of fruit, but also pay attention to the special conditions of the Nanguo North Transport.
Second, the basic conditions of Nanguo Beiyun (1), fruit quality. In the storage and transportation of fruits and vegetables, the quality of the fruit is a prerequisite for basic conditions. In Nanguo Beiyun, for a tree species, not only the choice of fruit should be emphasized, but more importantly, attention should be paid to the external quality (grade, shape, color, finish, etc.) and internal quality (maturity, nutrient content, hardness). , fragrances, etc.) and whether there are diseases, insects, etc.
(b) Pay attention to commercialization. The fruit of Nanguo Beiyun is a product after harvesting in the fruit producing area. After being processed into commercial products, it can be transported to the north, otherwise it will not achieve the intended purpose. The commercialization of the products of the southern evergreen fruit tree is more important and complicated than that of the northern fruits. The main contents of commercialized processing include strict selection, grading, cleaning, antiseptic treatment, single fruit packaging (excluding litchi, longan, bayberry, etc.), waxing, pre-cooling, etc., and some also require stacking of sweating pretreatment and labeling. Non-commercially processed fruits cannot be counted as commodities, but only processed products.
(c) Packaging. Packaging is not only a content of commercialization, but also a measure in long-distance transportation, or a technology in transportation preservation. The materials used for packaging can be broadly divided into three types. One is the inner packaging, which includes film and film bags inside the village, single-fruit packaging film bags, wrapping paper (including anti-corrosion plastic wrap), foam net cover, etc.; Including cartons (large cardboard boxes with small cardboard boxes), foam boxes, plastic boxes, wooden boxes, bamboo baskets, etc.; third, trademarks, patents, or green food signs attached to the outer packaging or single fruit. Therefore, good or bad packaging directly affects the quality of transportation and circulation benefits.
(D) Transport facilities. This is a very important basic condition for the Nanguo North Transport. At home and abroad, the main facilities for the transportation of fruits and vegetables are the following four:
l. Aircraft transportation. Radio transmission has the advantages of high speed, high transport quality, and light mechanical damage. However, shipping costs are high, there are many turnover links, and the shortcomings such as the rapid rise of fruit at high altitudes. The use of insulated containers will improve the quality of transportation.
2, cold storage ship transportation. Refers to ships with refrigeration equipment that can control lower transportation temperatures. Nanguo Beiyun is currently using a large number of ship-cold storage vessels in China, and the smallest cold storage vessels are also over 300 tons. Jianghuan cold storage vessels are rarely used. The use of cold storage vessels to carry out the Nanguo Beiyun mostly concentrated in the southeastern coastal provinces and fruits exported to Japan and South Korea. Due to its large volume of shipments and smooth sea movements, not only is the freight rate low, but also the transportation quality is high, but the time spent on transportation is longer. In the north of the boat, the Nanguo transport, in addition to the special transport of cold storage vessels, there are a considerable number of Nanguo transported by ordinary cargo carriers and mixed passenger and cargo ships. In the summer and autumn when the temperature is high, refrigerated containers are mostly used to carry out large-scale packaging and shipping. When the temperature is low in winter and spring, they are shipped directly.
3, train transportation. This is one of the largest transport equipment in China's current Nanguo North Transport. Train transportation, according to its different equipment, is divided into refrigerator car, ice truck and ordinary freight wagon. In general, five vehicle wagons are grouped into a group. One of the wagons is equipped with refrigeration control equipment. The other four wagons are refrigerated trucks, and a number of engine maintenance teams form a set (also mixed with other wagons). The ice carts are all single wagons. The wagons have double walls and are used to add crushed ice cubes with salt. During the train journey, as the salt ice cubes continue to melt, salt ice is added at fixed points. This type of ice-carrying vehicle fluctuates during the entire transportation process. In train transportation, the use of that type of wagon transport should be based on the temperature control conditions and the variety of transport fruit.
4, car transport. With the rapid development of China's highway industry and the accelerated construction of expressways, automobile transportation will also become the main mode of transport for Nanguobeiyun. The biggest advantage of the car is that it can reduce the number of turnovers of the fruit as much as possible, and the fruit turnover can be 2-3 from the place of production to the place of sale. For example, a vacuum rapid pre-cooling equipment in the production area is more effective. However, the biggest drawback of automobile transportation is the large bumps in transit, causing mechanical injuries during transportation. At present, the main types of domestic automobile transport facilities are two kinds of refrigerated and fresh-keeping vehicles with clear temperature and high temperature. The transport vehicle is equipped with refrigeration equipment and power supply equipment (generators); refrigerated container trucks; (Chemical); insulation car: ordinary trucks and other types. In some places there is also a "soil warmer" in transit.
(5) Precooling In the Nanguo North Transport, pre-cooling before fruit shipment is also a basic condition for the success of Nanguo North Transport. Under the specific phenological conditions of the tropics and subtropics in the south, after the fruit is harvested, it carries a lot of field heat, and at the same time, it constantly generates heat of respiration. If these two kinds of calories are brought into the transportation facilities at the same time, the product temperature will continue to rise, and the respiration intensity of the fruits will be continuously increased, the senescence of the fruits will be accelerated, and the harm of the diseases will be aggravated, and the rot of the fruits will be increased, directly affecting the quality of the fruits. . The purpose of pre-cooling is to remove the field heat and some of the heat of respiration brought by the fruit, thereby reducing the respiratory intensity of the fruit, delaying the aging of the fruit, and improving its resistance to storage and transportation. There are many methods for pre-cooling, which are roughly divided into four categories:
1, rely on natural cold source pre-cooling, this method is mostly used for fruit harvested in autumn and winter, such as citrus (excluding summer orange), winter harvested bananas and papaya. After harvesting, the fruits are prevented from cooling in the shade or using the nighttime low temperature for cooling.
2, pre-cooled ice water, add the right amount of ice in the water at room temperature, "wait for the ice to dissolve to a certain extent, when the water temperature reaches the desired temperature, the fruit is immersed in the water pre-cooling. This pre-cooling method is faster, the effect Better used for fruit harvested in spring and summer, such as litchi, longan, peach, summer orange and so on.
3, cold air pre-cooled. The cold air produced by mechanical refrigeration is used to lower the product temperature to a suitable temperature, and then the long-distance transportation is cold air precooling. Cold air precooling can be accomplished using a chiller, or it can be performed using a dedicated pre-cooling unit. As long as the fruit temperature is higher than the appropriate temperature during transportation, it can be cooled in this way.
4, vacuum rapid cooling. Using the vacuum rapid precooler, the transported Nanguo was reduced to a suitable temperature for transportation within a short period of time. This pre-cooling method is to put the fruit in a vacuum-sealed container, and use a rapid depressurization of the evacuation to complete the temperature. The principle of vacuum rapid precooling is to quickly evaporate a small amount of water in the state of ultra-low pressure during the depressurization process, so that the product temperature can be quickly reduced (20-30 minutes). This method is good for some fruits, but it is not obvious for other fruits, such as papaya, pineapple and so on.
Third, the main preservation technology of Nanguo Beiyun (1) In order to further master the main preservation technology in the Nanguo North Transport, we must first understand the storage and preservation technology of Nanguo. The following describes the preservation technology of 8 kinds of fruit in Nanguo and provides the parameters for preservation technology of Nanguo Beiyun: A summary of the main fruit preservation techniques in the South.
(II) Main transportation and preservation technologies of 8 kinds of Nanguo
1. Citruss: Among citrus, oranges, oranges, lemons, and extracts, most of the five categories are harvested in autumn and winter. At this time, the temperature is low, especially the oranges harvested in winter, when the harvest is close to the appropriate temperature for storage and transportation and preservation, natural cooling can be used for pre-cooling. However, the difference is that the relative humidity of the air in the south is very high, and there are many kinds of fruit diseases and the damage is severe. In particular, diseases such as chlorosis and phytophthora diseases are very strong. As long as the disease is in good contact, it will soon be It will be infected and rot. At higher temperatures, the rot rate is very high. Therefore, after the fruit is harvested, first of all, anti-corrosion treatment should be performed, and a certain amount of biological hormone (usually 4D-100PPm) should be added to the antiseptic solution to increase the activity of the cell tissue and prevent the atrophy, browning and shedding of the fruit pedicle. . In the commercialization, in addition to conscientiously doing a good job of sweating, cleaning (including removing the disease), and grading, it is necessary to pack the fruit and fruit, and to carry out the fruit of the larger citrus and orange, orange, lemon, cypress and other fruits. Wax, increase its product value. Southern evergreen fruit trees are vulnerable to cold damage at lower temperatures, and citrus fruits are no exception. There were some differences in chilling injury temperature among different types and varieties of citrus. Under normal circumstances, citrus and orange chilling injury temperature 3-goC (different varieties and different regions have different levels of temperature) orange chilling injury is 3-7oC (different origin and different varieties are also different, such as Sichuan Jincheng chilling temperature is 3.8 One, while the temperature of Xinhui orange and orange in Guangzhou is 65-7C), and lemon chilling temperature is 10-11.7OC. The chilling temperature for smoking is 5-10°C. After the chilling injury of citrus, its symptoms are also very different, such as citrus and orange cold damage, skin sag outside, or rot, edema disease occurs; du and lemon chilling injury, in addition to peel depression, the carpel wall brown Change, resulting in dryness (brown spot). According to the occurrence of chilling injury in citrus in different regions, regardless of the transport mode used in the Northern Transport, the fruit temperature in the transport should not be lower than the temperature at which cold damage occurs.
2. Bananas: In the banana growing area, it can be harvested all year round. According to folk customs, the bananas harvested in different seasons are called spring banana, summer banana, autumn banana and winter banana respectively. However, regardless of the different varieties of bananas harvested in that season, the following three technologies should be mastered in the Northern Campaign.
(1) Carry out commercialization of banana fruit. Bananas used for transport must be harvested during the hard maturation period (8-9). Because of the great difference in fruit ripeness in the panicles of bananas, strict grading is required in the debarking. The spikes harvested from the plants are transported to the processing site for de- combing, and various mechanical injuries must be strictly prevented. After de-combing, the banana should be washed immediately, and the solution should be soaked, dried and cooled. After being pre-cooled, it should be loaded into the 004-005mmp or PVC storage bag of Nakamura and transported by the truck.
(2) During banana transportation, the main causes of softening, rot, and peel darkening are the following three points: (a) The transport temperature is too high and the period of respiratory respiration is over. Although the peel is green, the pulp has reached full maturity. And become soft.
(3) Bananas have not been treated with antiseptic or improper anti-corrosion measures prior to transportation. In addition, high transportation temperatures cause banana anthracnose (invasion during growth period, long-term latency), and shaft rot (invasion of wounds or incisions) occurs greatly, prompting fruit and The comb shaft is rotted.
(4) There are two reasons for peel blackening: First, mechanical injury in transit, including smashing, touching, puncture, grinding, abrasions, etc.; Second, the transport temperature is too low, causing chilling injury leading to black skin. The temperature of banana chilling is 11.7-13.3°C. Therefore, the suitable temperature for banana north transport is 15-16°C. In view of the above situation, corresponding measures should be taken.
(5) Bananas are not very sensitive to low O2 and high CO2. During long-distance transportation, long-distance transportation using CA (modified atmosphere container transportation) and MA preservation (PE and PVC storage bag packaging) can be performed. .
3. Litchi: Litchi is mainly produced in China's Guangdong, Guangxi, Fujian, Yunnan, Hainan Island and other provinces, many varieties (more than 100 varieties), storage and transportation of great differences. Litchi's harvesting period is experiencing high temperatures in summer, and the consequences are extremely dark; the fruit flesh will also be rancid soon after 2-3 days at high temperatures. Therefore, it is not only resistant to storage and transportation, but also difficult to store at room temperature for 3-4 days. According to the biological characteristics and difficult-to-storage characteristics of post-harvest litchi, the following four measures must be taken by litchi.
(l) Pre-cooling must be done in time after harvest to reduce the temperature to soC. The lowest IC cannot be low, or cold damage will occur. At the same time, higher humidity (95% or more) must be given, otherwise skin peeling may also occur. The pre-cooling method can use ice water, cold air and vacuum rapid pre-cooling.
(2) On the skin and fruit branches of litchi, there are many diseases during the growing period, such as filth, downy mildew, gray mold, black rot and so on. Litchi should be sprayed before harvesting, cleaning up some of the pathogens on fruit branches and fruits; post-harvest treatment should be done to prevent rot during transportation, and antiseptic treatment should be combined with anti-peel browning.
(3) Anti-browning treatment. During the storage and sale of lychee, the prevention of browning of the peel is a major problem that must be solved in the preservation and preservation of litchi. The method to solve this problem should be carried out from two aspects. First, to maintain high humidity (RH95% or more), accompanied by a lower temperature (2-3oC); the second is to use anti-peel brown chemical treatment. The two-stage fumigation color protection and preservative agent of CT Litchi developed and produced by the National Agricultural Products Preservation Engineering Technology Research Center (Tianjin) has a good treatment effect.
(4) Since litchi can be tolerant of higher CO2 (-5%) and lower O2 (3-5%) during storage and transportation, the use of MA gas-conditioning during the Northern Games will be better. Improve the transportation effect. The use of 0.04-005mlnPE or PVC, J' packaging for preservation during transport not only maintains high humidity in the transport environment, but also uses high COZ and low horses to suppress the respiratory intensity of fruits and improve the preservation effect.
4. Longan. Longan fruits are more resistant to storage and transportation than litchi. The main manifestations are that the peel is not easy to brown, the fruit is more resistant to high COZ (4-6%), the humidity in the transport environment (RH90-95%) does not need to be too high, and the preservation time is longer Door 4 months) etc. Long-distance transport of longan must meet the following four conditions:
(1) It must be timely and harmless. The harvesting maturity should reach 9 and it is appropriate to harvest 15-16% of the fruit sugar content (soluble solids).
(2) In time pre-cooling, the pre-cooling temperature is 3-soC, and the pre-cooling method is similar to that of litchi.
(3), anti-corrosion treatment can be used 2-AB fumigation or fruit dipping, can also be used ThZ fruit wash.
(4) It can be quick-frozen and fresh-keeping, and then transported to the north. The quick-freezing temperature is 20 - 23 °C, and the temperature of transportation is a small one 10 °C. After thawing, use 05% citric acid and 003%V. Mixture treatment improves longan's freshness and flavor.
5. Hey. The bran is also a famous fruit in southern China and it is widely distributed in the south. The harvest dates earlier, mostly in May-June in the late spring and early summer. As a result of a small fruit, but also a more concentrated period of maturity, storage and transportation of fresh more difficult. In the past many years, it was reported that the preservation time was less than one month, and the time allowed for transportation was only 2-3 days. However, with the constant development of preservation technology, the preservation time can reach two months or more under suitable conditions, and the transportation time can be prolonged to 5-7 days. The specific technical measures are as follows:
(1) Choose the species with storage and transportation, such as bells, bells, pincers, dahongbao and other late-maturing varieties, and white sand is more difficult to store and transport.
(2), timely recovery without injury, post-harvest sll preservation treatment, and pre-cooling the fruit to 3-4oC, long-distance transport temperature can be controlled between 3-6oC.
(3) Packaging in transportation is very important. Whether it is preservation or transportation from the north, it is not allowed to use large packages. The amount of small packages should be controlled at l-Zkg. For ease of transportation, a small number of boxes can be packed and repacked into large boxes.
(4) The helium can be transported by MA, but it is necessary to strictly control the concentration of CO2 and O2. Usually O2 should be kept at 18%, COZ at 2-3%, and 002-003% PE or PVC bags are more suitable.
6, mango. In recent years, mangoes have developed rapidly in the south of China. The output has been increasing year by year and the variety has been increasing, especially in the Baise area of ​​Guangxi. Mango is a fruit that is difficult to keep fresh in the evergreen tree of the South, and it is also difficult to transport. The reason is that mango is a fruit with a significant period of respiration, and it reaches maturity, and the fruit is aging and can no longer be transported. On the other hand, there are many diseases during the fruit growth period, such as anthrax, peduncle, ring rot, and phytophthora, and some diseases have the ability to lurk in the infection, until the fruit is close to maturity and storage and transportation. harm. Therefore, to make long-distance transportation of mangoes, the following measures must be taken:
(1) Pay attention to the prevention and treatment of pre-harvest fruit diseases and bagging at the fruit growth period to reduce the harm of diseases. The fruit is sprayed with an efficient and low-toxic preservative before harvesting to remove pathogenic bacteria on the surface of the fruit and control the damage of the fruit during storage and transportation.
(2) Immediately after harvest, fruits are treated with a preservative (eg TBZ) and precooled with a temperature of 10°C. Can also be applied to wax the fruit (add appropriate amount of preservatives and human 4D hormone in fruit wax).
(3) Mangoes are fruits with a respiratory jump and are insensitive to low island high COZ. Therefore, DTCA or MA can be used for air transport during transportation, and 003-0.04mm fresh-keeping bags are used for inner packaging of fruit boxes.
(4) During the long-distance transportation of fruits, the temperature in the transportation environment should be maintained at 10-12oC. If the temperature is too low, cold injury will occur. Control humidity (RH is 90%).
7. Pineapple: Pineapple is a fruit tree with higher citric acid and stronger aroma. It is produced in Guangdong, Guangxi, Hainan Island and other provinces. Generally, it can be harvested l-2 times a year, treated with calcium carbide, and harvested 3 times a year. The fruit of pineapple can be eaten fresh and can be processed into canned food, fruit juice, and fruit wine. Pineapple Beiyun has a large circulation in the north. Long-distance transport of pineapple is easier, but the following issues should also be noted:
(l) After the pineapples have been harvested, the top buds must be removed to prevent the top buds from continuing to grow during transport, resulting in corkation of the fruit center. During harvesting, the fruit shank should be left with Zcm, and antiseptic treatment should be carried out to prevent the decay of the harvested wound pathogen causing invasion.
(2) The temperature should be controlled at 10-15oC during transportation. If it is lower than goC, it will cause cold damage (black heart disease). The humidity should not be too high (usually about 80%) to prevent decay. But the temperature should not be too high, otherwise it will speed up the carpentry of the heart and fruit rot.
(3) The fruit used for long-distance transportation is generally controlled to mature at 8-9 minutes. The ripe fruit and flesh are soft and easy to transport and produce more mechanical injuries.
8. Papaya: Papaya is a tropical fruit tree. Although it resembles a melon, it grows on a woody tree. Papaya is a dioecious plant, and only the female plants have migrated. A large fruit (usually in the l-Zkg), high nutritional value, soluble solids content of about 10%, with more protein and vitamins, especially high levels of vitamin A, C. The transport and preservation technology of papaya has the same place as other Nangoa. "There are also differences. The main points are as follows:
(1) Correctly grasp the transport maturity of papaya. Generally fully mature papaya, more than 80% of the husk appears yellow and yellow-brown, when harvesting, guati easily fall off, the flavor completely meets the original flavor of this species; 8-9 points mature papaya, is guati and Melon is yellowish-green and other melons appear light green, and some appear yellowish green; 7 ripe melons and guadi are light green or yellowish green, and other melons are green or light green. Papaya used for the Northern Games should be harvested at 7-8 minutes of maturity. When papaya 7 matures, the garden-shaped seeds have completely turned black.
(2) The difference between papaya skin and melon skin is that the melon skin is thin. During harvesting and transportation, mechanical injury can easily occur. But the same with Hami melon is prone to internal injuries. Therefore, the papayas to be transported should be packaged in a single melon, and the melon box can only be weighed in a single layer.
(3) Papaya pre-cooling and transportation temperature is 10-12°C and relative humidity is 70-80%.
(4) If the maturity level after harvesting and transportation is low, it can be completely cooked after 3-5 days treatment at 20-25 oC humidity. You can also use cooked methods to speed up post-cooking. The method of destructuring is to use concentrated lime water or concentrated alkalinity to drip into the pedicle of the fruit. It can also be dipped in ethephon 1000-1500ppm liquid for l-2 minutes. After each one for 2 days, it can reach ripeness, but the flavor of papaya is not as good as It's good to be cooked.
Second, the basic conditions of Nanguo Beiyun (1), fruit quality. In the storage and transportation of fruits and vegetables, the quality of the fruit is a prerequisite for basic conditions. In Nanguo Beiyun, for a tree species, not only the choice of fruit should be emphasized, but more importantly, attention should be paid to the external quality (grade, shape, color, finish, etc.) and internal quality (maturity, nutrient content, hardness). , fragrances, etc.) and whether there are diseases, insects, etc.
(b) Pay attention to commercialization. The fruit of Nanguo Beiyun is a product after harvesting in the fruit producing area. After being processed into commercial products, it can be transported to the north, otherwise it will not achieve the intended purpose. The commercialization of the products of the southern evergreen fruit tree is more important and complicated than that of the northern fruits. The main contents of commercialized processing include strict selection, grading, cleaning, antiseptic treatment, single fruit packaging (excluding litchi, longan, bayberry, etc.), waxing, pre-cooling, etc., and some also require stacking of sweating pretreatment and labeling. Non-commercially processed fruits cannot be counted as commodities, but only processed products.
(c) Packaging. Packaging is not only a content of commercialization, but also a measure in long-distance transportation, or a technology in transportation preservation. The materials used for packaging can be broadly divided into three types. One is the inner packaging, which includes film and film bags inside the village, single-fruit packaging film bags, wrapping paper (including anti-corrosion plastic wrap), foam net cover, etc.; Including cartons (large cardboard boxes with small cardboard boxes), foam boxes, plastic boxes, wooden boxes, bamboo baskets, etc.; third, trademarks, patents, or green food signs attached to the outer packaging or single fruit. Therefore, good or bad packaging directly affects the quality of transportation and circulation benefits.
(D) Transport facilities. This is a very important basic condition for the Nanguo North Transport. At home and abroad, the main facilities for the transportation of fruits and vegetables are the following four:
l. Aircraft transportation. Radio transmission has the advantages of high speed, high transport quality, and light mechanical damage. However, shipping costs are high, there are many turnover links, and the shortcomings such as the rapid rise of fruit at high altitudes. The use of insulated containers will improve the quality of transportation.
2, cold storage ship transportation. Refers to ships with refrigeration equipment that can control lower transportation temperatures. Nanguo Beiyun is currently using a large number of ship-cold storage vessels in China, and the smallest cold storage vessels are also over 300 tons. Jianghuan cold storage vessels are rarely used. The use of cold storage vessels to carry out the Nanguo Beiyun mostly concentrated in the southeastern coastal provinces and fruits exported to Japan and South Korea. Due to its large volume of shipments and smooth sea movements, not only is the freight rate low, but also the transportation quality is high, but the time spent on transportation is longer. In the north of the boat, the Nanguo transport, in addition to the special transport of cold storage vessels, there are a considerable number of Nanguo transported by ordinary cargo carriers and mixed passenger and cargo ships. In the summer and autumn when the temperature is high, refrigerated containers are mostly used to carry out large-scale packaging and shipping. When the temperature is low in winter and spring, they are shipped directly.
3, train transportation. This is one of the largest transport equipment in China's current Nanguo North Transport. Train transportation, according to its different equipment, is divided into refrigerator car, ice truck and ordinary freight wagon. In general, five vehicle wagons are grouped into a group. One of the wagons is equipped with refrigeration control equipment. The other four wagons are refrigerated trucks, and a number of engine maintenance teams form a set (also mixed with other wagons). The ice carts are all single wagons. The wagons have double walls and are used to add crushed ice cubes with salt. During the train journey, as the salt ice cubes continue to melt, salt ice is added at fixed points. This type of ice-carrying vehicle fluctuates during the entire transportation process. In train transportation, the use of that type of wagon transport should be based on the temperature control conditions and the variety of transport fruit.
4, car transport. With the rapid development of China's highway industry and the accelerated construction of expressways, automobile transportation will also become the main mode of transport for Nanguobeiyun. The biggest advantage of the car is that it can reduce the number of turnovers of the fruit as much as possible, and the fruit turnover can be 2-3 from the place of production to the place of sale. For example, a vacuum rapid pre-cooling equipment in the production area is more effective. However, the biggest drawback of automobile transportation is the large bumps in transit, causing mechanical injuries during transportation. At present, the main types of domestic automobile transport facilities are two kinds of refrigerated and fresh-keeping vehicles with clear temperature and high temperature. The transport vehicle is equipped with refrigeration equipment and power supply equipment (generators); refrigerated container trucks; (Chemical); insulation car: ordinary trucks and other types. In some places there is also a "soil warmer" in transit.
(5) Precooling In the Nanguo North Transport, pre-cooling before fruit shipment is also a basic condition for the success of Nanguo North Transport. Under the specific phenological conditions of the tropics and subtropics in the south, after the fruit is harvested, it carries a lot of field heat, and at the same time, it constantly generates heat of respiration. If these two kinds of calories are brought into the transportation facilities at the same time, the product temperature will continue to rise, and the respiration intensity of the fruits will be continuously increased, the senescence of the fruits will be accelerated, and the harm of the diseases will be aggravated, and the rot of the fruits will be increased, directly affecting the quality of the fruits. . The purpose of pre-cooling is to remove the field heat and some of the heat of respiration brought by the fruit, thereby reducing the respiratory intensity of the fruit, delaying the aging of the fruit, and improving its resistance to storage and transportation. There are many methods for pre-cooling, which are roughly divided into four categories:
1, rely on natural cold source pre-cooling, this method is mostly used for fruit harvested in autumn and winter, such as citrus (excluding summer orange), winter harvested bananas and papaya. After harvesting, the fruits are prevented from cooling in the shade or using the nighttime low temperature for cooling.
2, pre-cooled ice water, add the right amount of ice in the water at room temperature, "wait for the ice to dissolve to a certain extent, when the water temperature reaches the desired temperature, the fruit is immersed in the water pre-cooling. This pre-cooling method is faster, the effect Better used for fruit harvested in spring and summer, such as litchi, longan, peach, summer orange and so on.
3, cold air pre-cooled. The cold air produced by mechanical refrigeration is used to lower the product temperature to a suitable temperature, and then the long-distance transportation is cold air precooling. Cold air precooling can be accomplished using a chiller, or it can be performed using a dedicated pre-cooling unit. As long as the fruit temperature is higher than the appropriate temperature during transportation, it can be cooled in this way.
4, vacuum rapid cooling. Using the vacuum rapid precooler, the transported Nanguo was reduced to a suitable temperature for transportation within a short period of time. This pre-cooling method is to put the fruit in a vacuum-sealed container, and use a rapid depressurization of the evacuation to complete the temperature. The principle of vacuum rapid precooling is to quickly evaporate a small amount of water in the state of ultra-low pressure during the depressurization process, so that the product temperature can be quickly reduced (20-30 minutes). This method is good for some fruits, but it is not obvious for other fruits, such as papaya, pineapple and so on.
Third, the main preservation technology of Nanguo Beiyun (1) In order to further master the main preservation technology in the Nanguo North Transport, we must first understand the storage and preservation technology of Nanguo. The following describes the preservation technology of 8 kinds of fruit in Nanguo and provides the parameters for preservation technology of Nanguo Beiyun: A summary of the main fruit preservation techniques in the South.
(II) Main transportation and preservation technologies of 8 kinds of Nanguo
1. Citruss: Among citrus, oranges, oranges, lemons, and extracts, most of the five categories are harvested in autumn and winter. At this time, the temperature is low, especially the oranges harvested in winter, when the harvest is close to the appropriate temperature for storage and transportation and preservation, natural cooling can be used for pre-cooling. However, the difference is that the relative humidity of the air in the south is very high, and there are many kinds of fruit diseases and the damage is severe. In particular, diseases such as chlorosis and phytophthora diseases are very strong. As long as the disease is in good contact, it will soon be It will be infected and rot. At higher temperatures, the rot rate is very high. Therefore, after the fruit is harvested, first of all, anti-corrosion treatment should be performed, and a certain amount of biological hormone (usually 4D-100PPm) should be added to the antiseptic solution to increase the activity of the cell tissue and prevent the atrophy, browning and shedding of the fruit pedicle. . In the commercialization, in addition to conscientiously doing a good job of sweating, cleaning (including removing the disease), and grading, it is necessary to pack the fruit and fruit, and to carry out the fruit of the larger citrus and orange, orange, lemon, cypress and other fruits. Wax, increase its product value. Southern evergreen fruit trees are vulnerable to cold damage at lower temperatures, and citrus fruits are no exception. There were some differences in chilling injury temperature among different types and varieties of citrus. Under normal circumstances, citrus and orange chilling injury temperature 3-goC (different varieties and different regions have different levels of temperature) orange chilling injury is 3-7oC (different origin and different varieties are also different, such as Sichuan Jincheng chilling temperature is 3.8 One, while the temperature of Xinhui orange and orange in Guangzhou is 65-7C), and lemon chilling temperature is 10-11.7OC. The chilling temperature for smoking is 5-10°C. After the chilling injury of citrus, its symptoms are also very different, such as citrus and orange cold damage, skin sag outside, or rot, edema disease occurs; du and lemon chilling injury, in addition to peel depression, the carpel wall brown Change, resulting in dryness (brown spot). According to the occurrence of chilling injury in citrus in different regions, regardless of the transport mode used in the Northern Transport, the fruit temperature in the transport should not be lower than the temperature at which cold damage occurs.
2. Bananas: In the banana growing area, it can be harvested all year round. According to folk customs, the bananas harvested in different seasons are called spring banana, summer banana, autumn banana and winter banana respectively. However, regardless of the different varieties of bananas harvested in that season, the following three technologies should be mastered in the Northern Campaign.
(1) Carry out commercialization of banana fruit. Bananas used for transport must be harvested during the hard maturation period (8-9). Because of the great difference in fruit ripeness in the panicles of bananas, strict grading is required in the debarking. The spikes harvested from the plants are transported to the processing site for de- combing, and various mechanical injuries must be strictly prevented. After de-combing, the banana should be washed immediately, and the solution should be soaked, dried and cooled. After being pre-cooled, it should be loaded into the 004-005mmp or PVC storage bag of Nakamura and transported by the truck.
(2) During banana transportation, the main causes of softening, rot, and peel darkening are the following three points: (a) The transport temperature is too high and the period of respiratory respiration is over. Although the peel is green, the pulp has reached full maturity. And become soft.
(3) Bananas have not been treated with antiseptic or improper anti-corrosion measures prior to transportation. In addition, high transportation temperatures cause banana anthracnose (invasion during growth period, long-term latency), and shaft rot (invasion of wounds or incisions) occurs greatly, prompting fruit and The comb shaft is rotted.
(4) There are two reasons for peel blackening: First, mechanical injury in transit, including smashing, touching, puncture, grinding, abrasions, etc.; Second, the transport temperature is too low, causing chilling injury leading to black skin. The temperature of banana chilling is 11.7-13.3°C. Therefore, the suitable temperature for banana north transport is 15-16°C. In view of the above situation, corresponding measures should be taken.
(5) Bananas are not very sensitive to low O2 and high CO2. During long-distance transportation, long-distance transportation using CA (modified atmosphere container transportation) and MA preservation (PE and PVC storage bag packaging) can be performed. .
3. Litchi: Litchi is mainly produced in China's Guangdong, Guangxi, Fujian, Yunnan, Hainan Island and other provinces, many varieties (more than 100 varieties), storage and transportation of great differences. Litchi's harvesting period is experiencing high temperatures in summer, and the consequences are extremely dark; the fruit flesh will also be rancid soon after 2-3 days at high temperatures. Therefore, it is not only resistant to storage and transportation, but also difficult to store at room temperature for 3-4 days. According to the biological characteristics and difficult-to-storage characteristics of post-harvest litchi, the following four measures must be taken by litchi.
(l) Pre-cooling must be done in time after harvest to reduce the temperature to soC. The lowest IC cannot be low, or cold damage will occur. At the same time, higher humidity (95% or more) must be given, otherwise skin peeling may also occur. The pre-cooling method can use ice water, cold air and vacuum rapid pre-cooling.
(2) On the skin and fruit branches of litchi, there are many diseases during the growing period, such as filth, downy mildew, gray mold, black rot and so on. Litchi should be sprayed before harvesting, cleaning up some of the pathogens on fruit branches and fruits; post-harvest treatment should be done to prevent rot during transportation, and antiseptic treatment should be combined with anti-peel browning.
(3) Anti-browning treatment. During the storage and sale of lychee, the prevention of browning of the peel is a major problem that must be solved in the preservation and preservation of litchi. The method to solve this problem should be carried out from two aspects. First, to maintain high humidity (RH95% or more), accompanied by a lower temperature (2-3oC); the second is to use anti-peel brown chemical treatment. The two-stage fumigation color protection and preservative agent of CT Litchi developed and produced by the National Agricultural Products Preservation Engineering Technology Research Center (Tianjin) has a good treatment effect.
(4) Since litchi can be tolerant of higher CO2 (-5%) and lower O2 (3-5%) during storage and transportation, the use of MA gas-conditioning during the Northern Games will be better. Improve the transportation effect. The use of 0.04-005mlnPE or PVC, J' packaging for preservation during transport not only maintains high humidity in the transport environment, but also uses high COZ and low horses to suppress the respiratory intensity of fruits and improve the preservation effect.
4. Longan. Longan fruits are more resistant to storage and transportation than litchi. The main manifestations are that the peel is not easy to brown, the fruit is more resistant to high COZ (4-6%), the humidity in the transport environment (RH90-95%) does not need to be too high, and the preservation time is longer Door 4 months) etc. Long-distance transport of longan must meet the following four conditions:
(1) It must be timely and harmless. The harvesting maturity should reach 9 and it is appropriate to harvest 15-16% of the fruit sugar content (soluble solids).
(2) In time pre-cooling, the pre-cooling temperature is 3-soC, and the pre-cooling method is similar to that of litchi.
(3), anti-corrosion treatment can be used 2-AB fumigation or fruit dipping, can also be used ThZ fruit wash.
(4) It can be quick-frozen and fresh-keeping, and then transported to the north. The quick-freezing temperature is 20 - 23 °C, and the temperature of transportation is a small one 10 °C. After thawing, use 05% citric acid and 003%V. Mixture treatment improves longan's freshness and flavor.
5. Hey. The bran is also a famous fruit in southern China and it is widely distributed in the south. The harvest dates earlier, mostly in May-June in the late spring and early summer. As a result of a small fruit, but also a more concentrated period of maturity, storage and transportation of fresh more difficult. In the past many years, it was reported that the preservation time was less than one month, and the time allowed for transportation was only 2-3 days. However, with the constant development of preservation technology, the preservation time can reach two months or more under suitable conditions, and the transportation time can be prolonged to 5-7 days. The specific technical measures are as follows:
(1) Choose the species with storage and transportation, such as bells, bells, pincers, dahongbao and other late-maturing varieties, and white sand is more difficult to store and transport.
(2), timely recovery without injury, post-harvest sll preservation treatment, and pre-cooling the fruit to 3-4oC, long-distance transport temperature can be controlled between 3-6oC.
(3) Packaging in transportation is very important. Whether it is preservation or transportation from the north, it is not allowed to use large packages. The amount of small packages should be controlled at l-Zkg. For ease of transportation, a small number of boxes can be packed and repacked into large boxes.
(4) The helium can be transported by MA, but it is necessary to strictly control the concentration of CO2 and O2. Usually O2 should be kept at 18%, COZ at 2-3%, and 002-003% PE or PVC bags are more suitable.
6, mango. In recent years, mangoes have developed rapidly in the south of China. The output has been increasing year by year and the variety has been increasing, especially in the Baise area of ​​Guangxi. Mango is a fruit that is difficult to keep fresh in the evergreen tree of the South, and it is also difficult to transport. The reason is that mango is a fruit with a significant period of respiration, and it reaches maturity, and the fruit is aging and can no longer be transported. On the other hand, there are many diseases during the fruit growth period, such as anthrax, peduncle, ring rot, and phytophthora, and some diseases have the ability to lurk in the infection, until the fruit is close to maturity and storage and transportation. harm. Therefore, to make long-distance transportation of mangoes, the following measures must be taken:
(1) Pay attention to the prevention and treatment of pre-harvest fruit diseases and bagging at the fruit growth period to reduce the harm of diseases. The fruit is sprayed with an efficient and low-toxic preservative before harvesting to remove pathogenic bacteria on the surface of the fruit and control the damage of the fruit during storage and transportation.
(2) Immediately after harvest, fruits are treated with a preservative (eg TBZ) and precooled with a temperature of 10°C. Can also be applied to wax the fruit (add appropriate amount of preservatives and human 4D hormone in fruit wax).
(3) Mangoes are fruits with a respiratory jump and are insensitive to low island high COZ. Therefore, DTCA or MA can be used for air transport during transportation, and 003-0.04mm fresh-keeping bags are used for inner packaging of fruit boxes.
(4) During the long-distance transportation of fruits, the temperature in the transportation environment should be maintained at 10-12oC. If the temperature is too low, cold injury will occur. Control humidity (RH is 90%).
7. Pineapple: Pineapple is a fruit tree with higher citric acid and stronger aroma. It is produced in Guangdong, Guangxi, Hainan Island and other provinces. Generally, it can be harvested l-2 times a year, treated with calcium carbide, and harvested 3 times a year. The fruit of pineapple can be eaten fresh and can be processed into canned food, fruit juice, and fruit wine. Pineapple Beiyun has a large circulation in the north. Long-distance transport of pineapple is easier, but the following issues should also be noted:
(l) After the pineapples have been harvested, the top buds must be removed to prevent the top buds from continuing to grow during transport, resulting in corkation of the fruit center. During harvesting, the fruit shank should be left with Zcm, and antiseptic treatment should be carried out to prevent the decay of the harvested wound pathogen causing invasion.
(2) The temperature should be controlled at 10-15oC during transportation. If it is lower than goC, it will cause cold damage (black heart disease). The humidity should not be too high (usually about 80%) to prevent decay. But the temperature should not be too high, otherwise it will speed up the carpentry of the heart and fruit rot.
(3) The fruit used for long-distance transportation is generally controlled to mature at 8-9 minutes. The ripe fruit and flesh are soft and easy to transport and produce more mechanical injuries.
8. Papaya: Papaya is a tropical fruit tree. Although it resembles a melon, it grows on a woody tree. Papaya is a dioecious plant, and only the female plants have migrated. A large fruit (usually in the l-Zkg), high nutritional value, soluble solids content of about 10%, with more protein and vitamins, especially high levels of vitamin A, C. The transport and preservation technology of papaya has the same place as other Nangoa. "There are also differences. The main points are as follows:
(1) Correctly grasp the transport maturity of papaya. Generally fully mature papaya, more than 80% of the husk appears yellow and yellow-brown, when harvesting, guati easily fall off, the flavor completely meets the original flavor of this species; 8-9 points mature papaya, is guati and Melon is yellowish-green and other melons appear light green, and some appear yellowish green; 7 ripe melons and guadi are light green or yellowish green, and other melons are green or light green. Papaya used for the Northern Games should be harvested at 7-8 minutes of maturity. When papaya 7 matures, the garden-shaped seeds have completely turned black.
(2) The difference between papaya skin and melon skin is that the melon skin is thin. During harvesting and transportation, mechanical injury can easily occur. But the same with Hami melon is prone to internal injuries. Therefore, the papayas to be transported should be packaged in a single melon, and the melon box can only be weighed in a single layer.
(3) Papaya pre-cooling and transportation temperature is 10-12°C and relative humidity is 70-80%.
(4) If the maturity level after harvesting and transportation is low, it can be completely cooked after 3-5 days treatment at 20-25 oC humidity. You can also use cooked methods to speed up post-cooking. The method of destructuring is to use concentrated lime water or concentrated alkalinity to drip into the pedicle of the fruit. It can also be dipped in ethephon 1000-1500ppm liquid for l-2 minutes. After each one for 2 days, it can reach ripeness, but the flavor of papaya is not as good as It's good to be cooked.
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