Nature and Functional Mechanism of “+Double Fresh” “1-MCP” Preservative
Addtime:2014-10-17 Click:With the molecular formula of C4H6 and boiling point of about 10℃, “1-MCP” exists in the form of gas under the normal temperature without extraneous odor and it is unstable in the liquid state. “+Double Fresh” “1-MCP” Preservative absorbs and fixes the “1-MCP” gas in the carrier, and dissolves certain preparation in water according to the type of processed horticultural products and volume of closed container during use so that the “1-MCP” gas will be released.
Ethylene is a kind of gas with small molecule and plays an important role in the storage, transport and preservation of horticultural products. It can accelerate the yellowing, after-ripening, aging and drop of fruit, flowers and leaves. Ethylene with low concentration can greatly affect the plants or agricultural products which are harvested. Being called “accelerating hormone”, ethylene plays a vital role in changing the quality of fruit and vegetables during storage and transport. It can speed up the aging and after-ripening of fruit and vegetables after being picked. Especially, it can accelerate the yellowing and softening of green fruit and vegetables. Yellowing is an important feature for the aging of fruit and vegetables after being picked and is proved that ethylene resolves its chlorophyll; therefore, its aging process is closely related to ethylene.
Ethylene can affect the quality of agricultural products in many aspects based on crop type and the frequent harmful effects are shown as follows:
1. Promote the after-ripening and softening of fruit in advance: For climacteric fruit, such as banana, apple and mango which are stored and transported for a long time, ethylene will cause their after-ripening in advance, so they shall be sold as soon as possible after after-ripening. Peach, pear and some vegetables, including tomato, bitter gourd, face the same problem.
2. Fade the green of fruit: If lemons are sold in the domestic market, they shall keep bright green. Some oriental pears are light green. Chlorisis indicates the decrease of freshness and a little ethylene can fade the green of these fruit.
3. Increase the mildew and decay rate: Take strawberry as an example, ethylene will increase the mildew and decay of strawberry.
4. Promote the yellowing and drop of vegetables: Broccoli will be seriously yellowed because of ethylene with low concentration, most of leaf vegetables are yellowed when meeting with ethylene and some of leaves will fall off. Some fruit vegetables, such as cucumber, will yellow because of ethylene.
5. Urge fibrosis of stem vegetables. For example, the harvesting cut of asparagus and bamboo shoots will generate ethylene which can promote the fibrosis of cut base in advance and the fibrosis will extend to shoot tips so as to decrease the edible parts.
6. Degrade some vegetables, for example, it causes stored carrots to have bitter taste and causes lettuce to generate brown spots because of ethylene.
7. Urge fresh cut flowers to age and drop: For example, carnation, lily, violet and most of orchids will rapidly age after meeting with ethylene and buds will yellow and drop caused by ethylene.
8. Cause leaves of flowers to droop, soften and drop: For example, the leaves of poinsettia and various potted flowers will droop, soften and drop caused by ethylene.
The harm of ethylene may not be reflected obviously under well ventilated conditions, but it will play a tremendous role after being accumulated in a closed space. Most of agricultural products will generate ethylene of different amounts and mechanical injury, cutting part, mould and environmental influence will generate ethylene. To extend the storage life and keep freshness of horticultural products, it is very necessary to restrain the compound of ethylene inside organs or stop ethylene to work.
Ethylene plays a role by combining with protein of specific receptor inside plants and currently, ethylene receptor is regarded to be protein which contains Zn. “1-MCP” can combine with metal ions of ethylene receptor to stop the formation of ethylene receptor compound and block the transduction of the signal induced by ethylene. Therefore, before endogenous hormone of plants – ethylene is formed in quantity, “1-MCP” will combine with ethylene receptor to block the combination between ethylene and them, and the following reaction, and temporarily delay the physiological reaction of ethylene. “1-MCP” can eliminate the effect of ethylene and thus delay the ripening and aging processes of many fruit, vegetables, flowerrrangement and fresh cut flowers. “1-MCP” can play a durable role. Molecules of “1-MCP” combine with ethylene receptor irreversibly inside plants. Although the combination between molecules of “1-MCP” and ethylene receptor is irreversible, the new receptor can be formed when fruit enters into the jump-change stage and won’t affect the normal after-ripening of fruit and vegetables in the later stage of storage.
“1-MCP” is a new ethylene inhibitor which is recently found and can restrain the action of ethylene. The functional mechanism of “1-MCP” preservation is: When plant organs enter into the ripening period, ethylene will generate as the ripening hormone and combine with the related receptors inside cells to activate a series of physiological and biochemical reactions relating to ripening and accelerate the aging and death of organs. “l(fā)-MCP” which is similar to molecular structure of ethylene can also combine with these receptors to stop the formation of ethylene receptor compound and block the transduction of the signal induced by ethylene. Therefore, before plant endogenous hormone –ethylene is released, “1-MCP” will combine with the related receptors in advance, block their combination with ethylene and the following negative effect, delay the ripening process and achieve the fresh-keeping effect.
The main roles of “+Double Fresh” “1-MCP” Preservative on agricultural products are as follows:
Vegetables: “+Double Fresh” “1-MCP” Preservative has the following preservation roles: prevent the yellowing and wilting of leaf vegetables, reduce the breathing intensity and slow down the decrease of nutrition ingredient in the vegetables, keep or raise the taste of vegetables, decrease the requirements for low temperature during transport of vegetables and extend the shelf life of vegetables. For example, broccoli will seriously yellow when meeting with ethylene in low concentration, and will also yellow rapidly when being stored and transported in the temperature higher than 4.5℃. However, broccoli can extend its storage life after being processed by “+Double Fresh” “1-MCP” Preservative.
Fruit: The main problems of fruit during storage and transport are softening, color change, spot and brown stain. For example, after being picked, kiwi fruit, persimmon, and peach are easy to soften; therefore, after being processed by Preservative for Fruit and Vegetables (1-MCP), persimmon can extend its shelf life from 5 days to 15 or 20 days. In addition, for example, refrigerated apples are easy to have superficial scald, but when they are processed by Preservative for Fruit and Vegetables (1-MCP), superficial scald can be basically restrained and the hardness of applies can be delayed obviously. Therefore, the integrated quality is better than that of control group.
Flower: Many flowers are sensitive to ethylene. Generally speaking, “+Double Fresh” “1-MCP” Preservative can restrain the aging of fresh cut flowers caused by ethylene, effectively control the wither and boom of fresh cut flowers before maturity, decrease the browning of flowers and yellowing of leaves and prevent the drop of flowers and leaves. Especially, it can slow down the aging reaction of fresh cut flowers when there is trace ethylene in the transportation and sale environment, decrease the breathing intensity of fresh cut flowers during the storage and transport and extend the life of fresh cut flowers. According to many tests, after carnation is processed by “+Double Fresh” “1-MCP” Preservative, the flowering phase is 2 times longer than that of carnation which isn’t processed, the effect is obvious and the color of carnation which is processed is brighter. The processing effect of flowers which are processed by “+Double Fresh” “1-MCP” Preservative exceeds that of flowers which are processed by the traditional “STS”.
Like air-conditioned storage and MAP (modified atmosphere packaging) which have good preservation effect, “+Double Fresh” “1-MCP” Preservative is used for controlling ethylene. Physical preservation is mainly adopted for these storage methods and the harmful substances are not added during storage, so they belong to the scope of harmless and green physical preservation technology.
Therefore, it is necessary to specially mention two key factors which affect the life of agricultural products after being picked: breathing intensity and ethylene. Low temperature aims to reduce the breathing intensity and the output of ethylene. “+Double Fresh” “1-MCP” Preservative mainly aims to control ethylene. In addition, according to tests, “+Double Fresh” “1-MCP” Preservative can decrease the breathing intensity. Therefore, if low temperature and “+Double Fresh” “1-MCP” Preservative can be used together, they can better solve the breathing intensity and ethylene of agricultural products and protect agricultural products in an all-round way.
According to tests, “+Double Fresh” “1-MCP” Preservative is not only valid for climacteric agricultural products, but also valid for non-climacteric agricultural products (such as pepper and gladiolus).
“+Double Fresh” “1-MCP” Preservative is a way of processing agricultural products after being picked. Those agricultural products which are processed by “+Double Fresh” “1-MCP” Preservative can extend their shelf life than those not processed. “+Double Fresh” “1-MCP” Preservative can decrease the breathing intensity of agricultural products and alleviate the steep demand of agricultural products for low temperature so that agricultural products can extend their storage life even though they are in the environment with the temperature slightly higher than the suitable temperature, and can replace some roles of ice bottle and low temperature. In addition, “+Double Fresh” “1-MCP” Preservative can control the negative effect of ethylene appropriately, reduce the loss, and improve quality. Especially, some agricultural products shall be stored in a cold environment or shall be stored and transported for export sales and need good quality, so it is of great importance to control ethylene.
As a new ethylene inhibitor, “+Double Fresh” “1-MCP” Preservative has some advantages. As an active ingredient, “1-MCP” is a kind of gas, so it must be used in a relatively closed environment, such as greenhouse, refrigeration storage, container and packing case. It is valid in the room temperature and refrigeration condition. Due to its low use concentration, long action time and large processing quantity, “+Double Fresh” “1-MCP” Preservative is available for large-scale commercial applications. “+Double Fresh” “1-MCP” Preservative has broad applying prospect due to its easy to use and outstanding preservation effect.
Scope of application (tested and approved): Fruit: Banana, persimmon, apple, pear, apricot, peach, strawberry, plum, nectarine, kiwi fruit, melon and fruit of cucurbitaceae, avocado, mango, papaya, passion fruit, cantaloupe, pineapple and guava, etc.
Vegetables: Broccoli, cauliflower, spoon cabbage, green bean, green pea, green soya bean, tomato, lettuce, edible podded pea, celery, young garlic shoot, cabbage, potato, carrot, onion, cedrela sinensis, soybean, broad bean, hot pepper, asparagus, Chinese parsley, cucumber, pickled cucumber, balsam pear, shallot, day lily, globe artichoke, long bean, sweet corn and eggplant, etc.
“1-MCP” has passed the safety and non-toxicity examination and approval of Environment and Protection Association (announcement on the EPA website). It is available for fruit and vegetables, it is safe to persons, animals and environment and isn’t limited for dosage during use.
“+Double Fresh” “1-MCPPreservativeMolecularformula: C4H6 and molecular weight: 54Toxicity: LD50>5000mgkg; according to toxicity category, thepreservationistheactually nontoxic substance.
Nature: 1-MCP is a gas under the normal temperature, is a kind of small cycloolefin and is very active chemically. Appearance: White powder or white tablet. Package: Aluminum plastic bag, paper bag or medicine bottle. One gram of high-concentration powder can preserve the space with the volume of 15-16m3. Each micro-dose tablet can preserve one box of fruit and vegetables. Dosage: Suffocating and concentration:1PPM.