1-Methylcyclopropene (1-MCP) is a new type of ethylene inhibitor discovered in recent years. It can inhibit the effects of endogenous and exogenous ethylene in plants. The mechanism of action of 1-MCP preservative is: when plant organs In the mature stage, ethylene as a mature hormone will be produced and combined with the relevant receptors inside the cells to activate a series of physiological and biochemical reactions related to maturation and accelerate the aging and death of organs. And l-MCP, which has a similar molecular structure to ethylene, can also bind to these receptors, thereby preventing the formation of ethylene receptor complexes and blocking the signal transduction induced by ethylene. Therefore, before the release of endogenous ethylene in plants, use 1 -MCP preservatives will preemptively bind to relevant receptors, block the combination of ethylene and them and the subsequent negative effects, delay the ripening process, and achieve the effect of freshness preservation.
Ethylene is a gas with very small molecules. It plays an important role in the storage, transportation and preservation of horticultural products. It promotes the yellowing, post-ripening, aging and shedding of fruits, flowers, and leaves. Low concentrations of ethylene are harmful to plants or harvesting The latter agricultural products will play a big role. Ethylene is known as the "ripening hormone". Ethylene plays an important role in the quality change of fruits and vegetables after storage and transportation. It can accelerate the aging and after-ripening of harvested fruits and vegetables, especially to accelerate the yellowing and softening of green fruits and vegetables. role. Yellowing is an important feature of postharvest aging of fruits and vegetables. It has been proved that this is caused by the decomposition of chlorophyll by ethylene, and its development process is closely related to ethylene
The impact of ethylene on the quality of agricultural products is multi-faceted, and often varies according to the type of crops. The more common harmful effects are as follows:
1. Promoting early post-ripening and softening of fruits: Bananas, apples, mangoes and other menopausal fruits that need to be stored for a long time, ethylene will cause premature post-ripening, these fruits cannot be stored as soon as they are post-ripening, and must be sold as soon as possible. Peaches, plums, and some vegetables such as tomatoes, bitter gourds, etc. also have the same problem.
2. Make the fruit green: For example, domestic lemons should be kept bright green, and some oriental pear fruit belts have a little green color, which means that the freshness is reduced; low amount of ethylene will make these fruits green.
3. Increase the moldy rate of fruit: such as strawberries, ethylene will increase moldy and rot.
4. Yellowing and shedding of vegetables: Broccoli will be seriously yellowed under very low concentration of ethylene. Most of the leafy vegetables will be yellowed when they encounter ethylene, and some of them will lose their leaves. Some fruits and vegetables such as courgettes are also yellowed by ethylene.
5. Promoting the fibrosis of stem vegetables: such as asparagus and bamboo shoots, the incision of harvesting will produce ethylene, and ethylene will make the base of the incision fibrillate early, and the fibrosis will extend to the tip of the stem, reducing the edible parts.
6. It causes special deterioration of some vegetables: for example, stored carrots have a bitter taste due to ethylene, and lettuce has brown spots due to ethylene.
7. Aging and shedding of cut flowers: such as carnations, lilies, violets, and most orchids, etc., will age rapidly when they encounter ethylene, and the flower buds will turn yellow due to ethylene and then fall off.
8. Make flower leaves droop and fall off: such as Christmas red and various potted flowers, the leaves droop and fall off due to the influence of ethylene.
The hazards of ethylene may not be obvious under well-ventilated conditions, but its impact can be great after accumulation in a closed space. Most agricultural products will produce ethylene, but the amount of production is different. Mechanical damage, cutting parts, mold, and environmental impacts will all produce ethylene. In order to prolong the storage life of horticultural products and keep them fresh, it is necessary to inhibit the synthesis of endogenous ethylene in organs as much as possible or prevent ethylene from functioning.
Ethylene plays a role by binding to specific receptor proteins in plants. At present, it is believed that ethylene receptors may be Zn-containing proteins. 1-MCP can bind to metal ions of ethylene receptors, inhibit the formation of ethylene receptor complexes, and prevent the formation of ethylene receptor complexes. Signaling induced by ethylene breakage. Therefore, before a large amount of endogenous ethylene is formed in plants, the use of "1-MCP" will preemptively bind to ethylene receptors, block the combination of ethylene with them and the subsequent effects, and temporarily delay the physiological response of ethylene. 1- MCP can eliminate the effect of ethylene, thereby delaying the ripening and aging process of many fruits, vegetables, flower arrangements and cut flowers. The effect of 1-MCP is persistent. In plants, 1-MCP molecules bind irreversibly to ethylene receptors. Although the binding of 1-MCP to receptors is irreversible, new receptors can be formed when the fruit enters the transition period , The late storage period does not affect the normal post-ripening of fruits and vegetables.
