On November 20th 2018, Dora Agri applied 1-Methylcyclopropylene on apples to research the the significance of 1- MCP in apple preservation.
The results showed:1-Methylcyclopropylene(1-MCP) maintained a high content of soluble solids and VC, significantly inhibited the increase in the rate of ethylene production, relative conductivity, and malondialdehyde content of the fruit, and effectively increased the activity of peroxidase and reduced The activity of polyphenol oxidase is improved, and the fruit quality is better maintained. (More details of 1-MCP)
The effect of 1-MCP will change due to the period of use of 1-MCP, and the effect of 1-MCP treatment within 12 days after harvest is better.
Therefore, the apples should be treated with 1-MCP as soon as possible after harvest, and it is advisable to store them under low-temperature conditions for no more than 12 days.
1-MCP on Fruits Apple
After harvesting, the apples were placed at low temperature for 0, 6, 12, 18, and 24 days, and then treated with 1-methylcyclopropene (1-MCP) for preservation. Compare the effects of 1-MCP treatment at different periods after harvest on the physiology and quality of apples during cold storage.
1. Effect of 1-MCP on Fruits Apple TSS Content
The TSS content of apple fruits in each treatment group showed a gradual decrease during storage. After 60 days of storage, there was no significant difference between the groups. (P>0.05), TSS content is 1-MCP-0 d>1-MCP-6 d>1-MCP-12 d>1-MCP-18 d>1-MCP-24 d>control group.
The TSS content of apple fruits in each treatment group showed a gradual decrease during storage. After 60 days of storage, there was no significant difference between the groups. (P>0.05), TSS content is 1-MCP-0 d>1-MCP-6 d>1-MCP-12 d>1-MCP-18 d>1-MCP-24 d>control group.
After storage for 120 d, 1-MCP-0 d, 1-MCP-6 d TSS content was significantly higher than other 1-MCP treatment groups (P<0.05). After 180 days of storage, the TSS content of apple fruits in the 1-MCP treatment group was higher than that in the control group, indicating that 1-MCP can maintain a higher TSS content in the fruits.
After 240 days of storage, the TSS content of the 1-MCP-0 d treatment group was 11.34%, which was significantly higher than other treatment groups and controls (P<0.05), indicating that 1-MCP can maintain a higher TSS content, but its content varies with treatment The time delay is reduced.
2. Effect of 1-MCP on VC Content of Apples
The VC content of each group of fruits increased first and then decreased.
After 60 days of storage, the VC content of the apple fruit reached its peak during the entire storage process. The content of the control group was lower than that of the 1-MCP treatment group, indicating that 1-MCP could maintain the VC content of the fruit.
Compared with the treatment group, the VC content of the 1-MCP-0 d and 1-MCP-6 d treatment groups was significantly higher than that of the 1-MCP-18 d and 1-MCP-24 d (P＜0.01), 1-MCP-0 d, 1-MCP-6 d has no significant difference (P>0.05), indicating that the effect of 1-MCP treatment decreases with the delay of treatment time.
After storage for 120 d, the 1-MCP-0 d treatment group was significantly higher than other treatment groups (P＜0.05). At the end of storage, the VC content of each group was 1-MCP-0 d>1-MCP-6 d>1-MCP-12 d> 1-MCP-18 d>1-MCP-24 d>control group.
3. Effect of 1-MCP on the MDA Content of Apples
During the storage period, the MDA content of the fruits showed an upward trend.
After storage for 120 d, the MDA content of 1-MCP-0 d and 1-MCP-6 d treatment groups was significantly lower than other groups (P<0.05), and the MDA content of 1-MCP-0 d was only 2.16 μmol/g;
The MDA content of fruits stored for 120 d, 1-MCP-0 d and 1-MCP-6 d was significantly lower than that of the control group (P＜0.01), and significantly lower than 1-MCP-12 d, 1-MCP-18 d, 1-MCP-24 d (P<0.05).
From 180 days to the end of storage, the MDA content of 1-MCP-0 d was still the lowest, and the MDA content of other treatments was 1-MCP-6 d＜1-MCP-12 d＜1-MCP-18 d ＜1 -MCP-24 d <control group.
The difference between 1-MCP-0 d, 1-MCP-6 d and 1-MCP-12 d was not significant (P>0.05), while the difference between 1-MCP-18 d, 1-MCP-24 d and the control was not significant ( P>0.05), indicating that 1-MCP can inhibit the increase of MDA content, but the treatment effect decreases with the delay of 1-MCP treatment time.
Therefore, processing the apples within 12 days after harvesting can prolong the senescence rate of the fruits and better maintain the freshness of the fruits.
4. Effect of 1-MCP on the Relative Conductivity of Apples
During the storage period, the relative electrical conductivity of the treated fruits of each group showed an upward trend.
After storage for 120 d, the relative conductivity of the fruits of the control group, 1-MCP-18 d, 1-MCP-24 d treatment group was significantly higher than that of 1-MCP-0 d, 1-MCP-6 d, 1-MCP-12 d (P<0.05).
The difference between the control group, 1-MCP-18 d and 1-MCP-24 d was not significant (P>0.05), indicating that 1-MCP treatment can slow down the increase in the relative conductivity of the fruit and reduce the damage of the cell membrane, but with the treatment The time delay is reduced.
After storage for 180 d, the 1-MCP-0 d treatment group was lower than the other treatment groups, and the relative conductivity of each group was the control group＞1-MCP-24 d＞1-MCP-18 d＞1-MCP-12 d＞1- MCP-6 d>1-MCP-0 d.
After 240 d of storage, the relative conductivity of 1-MCP-0 d was 22.61%, which was significantly lower than that of other treatment groups (P<0.01).
The control group was 36.3%, which was 1.92, 1.27, 1.18, 1.2, 1-MCP-0 d, 1-MCP-6 d, 1-MCP-12 d, 1-MCP-18 d, 1-MCP-24 d. 1.13 times. It shows that the fruits should be treated with 1-MCP as soon as possible after harvest.
5. Effects of 1-MCP on the Rate of Ethylene Production of Apples
During storage, the ethylene production rate of apple fruits showed an upward trend.
After 60 days of storage, the ethylene production rate of the fruits of the control group was significantly higher than that of the 1-MCP treatment group (P<0.01), and the difference between the 1-MCP treatment groups was not significant (P>0.05).
After storage for 120 d, the ethylene production rate of the 1-MCP-0 d treatment group was 0.47 μL/(kg·h), which was significantly lower than the other groups (P＜0.05). Among them, the ethylene production of the 1-MCP-6 d treatment group rate. The minimum is 44 μL/(kg·h).
After 180 days of storage to the end of the storage period, the ethylene production rate of the treatment group was: control group＞＞1-MCP-24 d＞1-MCP-18 d＞1-MCP-12 d＞1-MCP-6 d＞1-MCP- 0 d, indicating that 1-MCP can inhibit the increase of ethylene production rate, the earlier the 1-MCP treatment time after harvest, the better.
6. Effect of 1-MCP on Apple PPO Activity
After 60 days of storage, the PPO activity of the fruits of the control group was significantly higher than that of the 1-MCP treatment group (P<0.05), indicating that the 1-MCP treatment can inhibit the browning of the fruits.
Among them, 1-MCP-0 d and 1-MCP-6 d treatment groups had lower fruit PPO activity than other treatment groups.
After storage for 120 d, the PPO activity of the fruits of the 1-MCP-0 d treatment group was significantly lower than that of the other groups (P<0.01). The PPO activity of each group: control group>1-MCP-24 d>1-MCP-18 d>1 -MCP-12 d>1-MCP-6 d>1-MCP-0 d.
It shows that the earlier the 1-MCP processes the fruit under low temperature conditions, the better the effect of inhibiting PPO activity. At the end of storage, there was no significant difference in PPO activity of the treated fruits of each group (P>0.05).
7. Effect of 1-MCP on the Activity of Apple POD
After 60 days of storage, the POD activity of fruits in the control group was significantly lower than that of the 1-MCP treatment group, indicating that 1-MCP treatment can significantly increase the POD activity.
Compared with the treatment group, the POD activity of the 1-MCP-0 d group was significantly higher than that of the other groups (P<0.05), and the POD activity was 3.88 0.01ΔA/(g·min).
After storage for 120 days, the POD activity size was 1-MCP-0 d>1-MCP-6 d>1-MCP-18 d>1-MCP-12 d>control group>1-MCP-24 d. There was no significant difference between 1-MCP-6 d, 1-MCP-18 d, and 1-MCP-12 d (P>0.05).
The difference between the control group and 1-MCP-24 d was not significant, indicating that the earlier the 1-MCP treatment, the higher the POD activity and the slower the fruit senescence.
1-MCP on Apple Conclusion
Treating apples with 1-MCP immediately after harvesting can effectively delay the maturation and senescence of apples. 1-MCP can inhibit the normal binding of ethylene and receptors, thereby weakening the catalysis of ethylene on the fruit, delaying the ripening of the fruit and extending the shelf life. .
Compared with the control, 1-MCP treatment immediately after harvest can slow down the decrease of TSS and VC content, significantly inhibit the increase of the ethylene production rate, relative conductivity and MDA content of the fruit, increase the activity of POD and reduce the activity of PPO , Delay the senescence process of the fruit.