Vegetables can not be guaranteed to be sold immediately after picking. How to keep vegetables in the best condition for picking is the primary concern of vegetable farmers. Vegetables are still a living organism in storage, and they need to resist the adverse environmental and pathogenic microorganisms. , maintain quality, reduce losses, and extend storage. Therefore, the normal life process of fresh vegetables must be maintained during storage to minimize changes in appearance, color, weight, hardness, taste, flavor, etc., in order to achieve the purpose of preservation. For this reason, it is necessary to adopt appropriate preservation techniques for the physiological changes of vegetables after harvest to promote the healthy development of the vegetable industry in China.
First, reduce the respiration, extend the storage period
In the storage of vegetables, the respiratory intensity should be reduced as much as possible, and the more vigorous the respiration, the faster the change of various physiological processes and the sooner the termination of life, which is not conducive to storage. The difference in the respiratory intensity of vegetables depends on the species, breed, and age. Leaf vegetables usually have the highest respiratory intensity, fruit and vegetable are the second, and roots, tubers and bulbs are the least. Late maturing species have stronger respiratory intensity and weaker precocious species. Younger stage has stronger respiratory intensity and weaker mature stage. In addition, temperature, atmospheric composition, mechanical injury, pests and diseases also have a great influence on the respiration of vegetables. High temperature, high respiratory intensity, between 5-35°C, every 10°C increase, respiratory intensity increases 1-1.5 times, exceeds 35°C, respiratory intensity drops dramatically; low temperature, weak respiratory intensity, consumes more nutrients Less, but do not think that the lower the storage temperature, the better. Reducing the concentration of oxygen in the air, breathing will be suppressed, usually the oxygen concentration is reduced to about 5%, and the effect is good. Vegetables that are damaged by machinery and pests will increase their breathing and should be removed when selecting storage samples.
An effective method to reduce the respiration of stored vegetables is air fresh-keeping. This method is based on the mechanical refrigeration, adjust the gas concentration in the storage environment, mainly to reduce the concentration of oxygen, increase the concentration of carbon dioxide, in order to inhibit the respiratory metabolism of post-harvest vegetables, reduce the consumption of nutrients . At present, China's application of more air-conditioned fresh-keeping technology is a small package of plastic bags, air-conditioning, large-scale changes in the atmosphere of plastic and silicone rubber window atmosphere. In addition, there is a vacuum storage method, which is to reduce the pressure of the storage place, generally to 1/10 of the atmospheric pressure, resulting in a certain degree of vacuum, so as to achieve the purpose of reducing oxygen, which is a new technology for the preservation of vegetables and many other foods , is the further development of modified atmosphere refrigeration. The scope of decompression storage is wider, spinach, lettuce, green beans, shallots, radishes, mushrooms, tomatoes and other species have better storage under reduced pressure. The best storage effect using this method is tomato, and the fresh-keeping period can reach 3 More than month.
Second, reduce the transpiration of storage
The moisture content of fresh vegetables is as high as 65-95%. It is easy to evaporate and dehydrate in storage. If it is not supplemented, it will cause wilting, wrinkling, and fade of luster, which will cause weightlessness of vegetables and reduce the quality of food. Therefore, it is very important to reduce the transpiration and wilting of storage vegetables. According to the characteristics of different vegetables, the environmental conditions during storage should be controlled. For example, the leaf surface area of ​​leafy vegetables is larger, the stomata of the growing leaves and young leaves are larger, and the transpiration is serious. , Dehydration and wilting most easily during storage. Therefore, it is necessary to increase the air humidity of the storage room (library) and reduce the air flow, so that the storage dish is in a high-humidity environment and the transpiration is minimized. In addition, the use of appropriate packaging materials is also an effective measure to improve preservation technology. For vegetables with strong evaporation of moisture, etc., it is better to use anti-turbid packaging materials. Such films are hydrophobic. To increase the hydrophilicity, surfactants can be coated to make the film surface with a thin film of water. This can not only prevent turbidity, but also prevent Water condensation in the package. Water evaporation inhibitors, ethylene adsorbents, bactericides, coolants, etc. can also be added to the package to help preserve freshness.
Third, post-harvest post-harvest and aging inhibition
Fruit vegetables, knots, root vegetables, etc., have a ripening effect during storage. In the process of ripening, a series of physiological and biochemical changes often occur. For example, the starch is hydrolyzed into sugar, the content of organic acids is reduced, the tannins begin to solidify and oxidize, the protopectin is decomposed into pectin dissolved in water, chlorophyll decomposes, and the flavor is improved. Produces aromatic ingredients with a hard texture that softens. Therefore, by utilizing this post-maturation, vegetables can be harvested earlier and suitable conditions can be created during storage to maintain the subsequent ripening power. The commonly used method is to reduce the temperature of the storage room, maintain high humidity, timely ventilation, eliminate accumulated ethylene and other gases, inhibit the activity of hydrolytic enzymes, delay the hydrolysis rate, prevent the consumption of nutrients, can achieve inhibition of post-maturation, prolong storage The purpose of the period.
From the beginning of harvest, vegetables will enter the aging stage, showing a decrease in the number of ribosomes in the cell's inner core, the collapse of the chloroplasts, the reduction of mitochondria, the aging of the cells, the impatience of storage, and the perishability. Aging is closely related to the content of ethylene, gibberellin, or other hormones in vegetables and changes in storage, the growth and development of vegetables, and storage conditions. To delay the aging of vegetables and prolong the storage period, first, select healthy and well-growing vegetables for storage; Second, strictly control the content of ethylene and other hormones in the storage of vegetables in order to delay the aging of vegetables; Third, to create the best storage Conditions, such as control of temperature and humidity, gas composition and proportioning.
Fourth, pay attention to the pre-cooling and low-temperature storage in the production area and reduce the loss of food storage
Precooling in production areas is the key to the preservation of vegetables after harvest. With the development of vegetable exports, pre-cooling of vegetable production areas is increasingly valued. The role of pre-cooling is to quickly remove field heat, effectively reduce the vegetable's own metabolic level, reduce nutrient consumption, delay aging, and extend the shelf life of vegetables. At high temperatures, prolonging the time it takes to receive precooling from the harvest will promote the aging of the vegetables and significantly shorten the shelf life of the vegetables. Low temperature can effectively inhibit the growth and activity of rot bacteria and reduce losses. It is also a key factor for storing vegetables. After the vegetables are pre-cooled in the production area, they are transported by the refrigerated container and entered into circulation. After being sold to the market, they enter the refrigerated warehouse or sales refrigerated cabinet, which can maximize the quality of the vegetables and reduce the circulation loss. Because various vegetables have different reactions to temperature, determining the storage temperature of vegetables must be based on the adaptability of the vegetables to low temperatures. For example, green ripe tomato storage temperature is 10-12°C, sweet pepper is 7-9°C, cucumber is 10-13°C, radish is 1-3°C, carrot is 0-1°C, potato is 3-5°C, spinach It is -6 to 0°C, cauliflower is 0 to 0.5°C, onion is -3 to 0°C, and garlic is -1 to 0°C. It can be seen that most of the vegetables are suitable for storage at low temperatures around 0°C. If it is lower than this temperature, vegetables will also be frozen. After the vegetables are frozen, the tissues and cells are destroyed by mechanical forces and produce dehydration. Some of the vegetables were destroyed after the cells were frozen; after thawing, the juice bleeds, losing the commodity and food value. However, some vegetables are more tolerant to cold, such as spinach can be rejuvenated at -9 °C, suitable for frozen possession.
V. Delay material conversion and consumption and maintain the quality of storage
After the harvest of vegetables, the accumulation of substances ceases, the dry matter no longer increases, and various substances that have been stored are gradually consumed, or under the catalysis of enzymes, undergo transformation, transfer, decomposition and recombination, and the morphology, structure, and characteristics of the tissues and cells. A series of changes have taken place in such aspects. If the cabbage tastes sweet after storage,
Soft texture, green fade. The green ripe tomato is hard and green, gradually degreening during storage and appears red or yellow, the flesh is softened, the acidity is reduced, and the vegetable flavor, texture, nutritional value, commerciality, storability and disease resistance are all significantly changed. .
During the storage of vegetables, the dynamic equilibrium of the synthesis-hydrolysis of various substances is constantly changing. The synthesis process of most vegetables during storage is gradually weakened, the hydrolysis process is continuously strengthened, and simple hydrolysates are accumulated, thereby stimulating respiration and being conducive to microbial infection. The conversion of pectin substances reduces the mechanical resistance of vegetables.
The change in the color of vegetables is often a sign of aging. At the same time, vitamin C in vegetables gradually decreases at different speeds during storage. For this reason, delaying the transformation and consumption of nutrients in vegetables is one of the keys to maintaining the quality of the dishes. Commercial use of reduced respiration, inhibition of ripening and aging, creation of optimal storage conditions and gas composition, etc. can all be satisfied. result.
Six, improve the tolerance and disease resistance
The storage tolerance of vegetables means that after a period of storage, the food value and flavor characteristics are not significantly reduced, and the weight loss is small; the disease resistance is the ability to resist the invasion of rot bacteria. The two are closely related to each other and depend on each other. Vegetables with high tolerance to Tibet have strong immunity against rot bacteria, and vice versa. In terms of the characteristics of vegetables, vegetables that use vegetative organs as edible parts, such as vegetables, spinach, celery, mustard, garland chive, leeks, spinach, sorghum, etc., have more water content, more types and quantities of enzymes, strong respiratory metabolism, and substance decomposition. Fast, mostly intolerant of storage, poor disease resistance. Young cucumbers, loofahs, beans, peppers, and eggplants are not tolerant of storage, while old ripe wax gourds and pumpkins are more resistant to storage. Vegetables with nutrient-accumulating organs as edible parts - tubers, tuberous roots, leaf balls, and bulbs - are also more resistant to storage, among which late-maturing species are more resistant to storage than early maturing species and have better disease resistance.
Pain Relief Patch for Breast
[Name] Medical Cold Patch
[Package Dimension] 10 round pieces
The pain relief patch is composed of three layers, namely, backing lining, middle gel and protective film. It is free from pharmacological, immunological or metabolic ingredients.
[Scope of Application] For cold physiotherapy, closed soft tissue only.
[Indications]
The patches give fast acting pain relief for breast hyperplasia, breast fibroids, mastitis, breast agglomera tion, swollen pain.
[How To Use a Patch]
Please follow the Schematic Diagram. One piece, one time.
The curing effect of each piece can last for 6-8 hours.
[Attention]
Do not apply the patch on the problematic skin, such as wounds, eczema, dermatitis,or in the eyes. People allergic to herbs and the pregnant are advised not to use the medication. If swelling or irritation occurs, please stop using and if any of these effects persist or worsen.notify your doctor or pharmacist promptly. Children using the patch must be supervised by adults.
[Storage Conditions]
Store below 30c in a dry place away from heat and direct sunlight.
Pain Relief Patch For Breast,Pain Relief Plaster For Breast,Relief For Breast Pain,Pad Relief Patch For Breast
Shandong XiJieYiTong International Trade Co.,Ltd. , https://www.xjpatches.com