How should plums be stored to keep them fresh longer?
The plum is the fruit of the plant Prunus salicina in the genus Prunus of the rose family (Rosaceae), also known as Jiaqingzi, Yuhuang plum, mountain plum, etc. It usually ripens between July and August, is plump and round, delicate and exquisite, beautiful in form, sweet in taste, and rich in nutrients. It has the effects of tonifying the middle and boosting qi, nourishing yin and promoting fluid production, moistening the intestines and relieving constipation, and smoothing the skin. Now let us take a look at how plums can be kept fresh for a long time!
When do plums ripen?
Different varieties of plums ripen at different times. Generally, the earliest varieties can ripen in May to June, and early-ripening varieties begin to appear on the market in early June, but the best-tasting varieties usually ripen between August and September. Plums are cultivated in all provinces and regions of China, mainly produced in Liaoning, Jilin, Shaanxi, Gansu, Sichuan, Yunnan, Guizhou, Hunan, Hubei, Jiangsu, Zhejiang, Jiangxi, Fujian, Guangdong, Guangxi and Taiwan, China.
How are plums kept fresh and stored?
1. Ice cellar storage: Spread crushed ice evenly over the bottom of the cellar, then place the pre-cooled fruit baskets on the ice and stack them. Fill the spaces between layers with crushed ice, and also fill the spaces between stacks with crushed ice. After stacking, cover the fruit stacks with crushed ice, then cover them with plastic film, and on top of the film pile 70 to 100 cm of insulating material such as sawdust. It is essential to keep the cellar door closed, and the cellar temperature is best controlled at 0 to 1 degrees Celsius. When entering or leaving the cellar, the door should be closed quickly. Plums stored in mid-to-late August can be kept until the Start of Winter, and can then be transferred to an ordinary cellar to continue storage until they are supplied to the market at Spring Festival.
2. Controlled atmosphere storage
① Gas-controlled storage: Store plums sealed in polyethylene film bags 0.025 mm thick. At an air temperature of 0 to 1 degrees Celsius, a carbon dioxide content of 7% to 8%, and an oxygen content of 1% to 3%, they can be stored for 70 days.
② Small-bag cold storage: Remove the stems from the plums, discard diseased, insect-damaged, bruised and rotten fruit, then put them into small polyethylene film bags, 1 to 1.5 kg per bag. After sealing, they can be kept for 2 to 3 months at a temperature of minus one degree.
Tips for selecting plums
1. Color: Plums that are dark red or purplish red can be eaten directly. Those that are pale and slightly greenish and glossy are generally 80% ripe. If you will eat them the same day, you can buy dark red ones; if you need to eat them after 2 days, you can choose ones that are slightly greenish and glossy.
2. Firmness: Plums that are very hard on the outside are unripe plums. Those that are firm but slightly soft are relatively well ripened, while those that are over-sunken or even dented are over-ripe plums. If juice seeps out, it means the fruit has already spoiled.
3. Smell: Plums have a rather distinctive fragrance. Unripe plums have little smell when sniffed, those with a faint fresh fragrance on the outside are ripe plums, and plums with a very strong fragrance on the outside indicate that they are over-ripe.
4. Flesh: The fruit of the plum is relatively small. The flesh of unripe plums is rather dry and astringent and somewhat green in color, while ripe plums generally have relatively sweet, fragrant and juicy flesh. The flesh of unripe plums tastes slightly bitter.
What are the benefits of eating plums?
1. Promoting digestion: Plums can promote the secretion of gastric acid and gastric digestive enzymes and have the effect of increasing gastrointestinal peristalsis, thereby promoting digestion and increasing appetite. They are a good dietary remedy for people with insufficient gastric acid, post-meal bloating, and constipation.
2. Clearing the liver and promoting water metabolism: Plum flesh contains a variety of amino acids, such as glutamine, serine, glycine, proline, etc. Eating them raw is of great benefit for treating ascites due to cirrhosis.
3. Promoting water metabolism and lowering blood pressure: Plum kernels contain amygdalin and a large amount of fatty oil, have a significant effect in promoting water metabolism and lowering blood pressure, and can also speed up intestinal peristalsis and promote the excretion of dry stool. They also have the effect of relieving cough and resolving phlegm.
4. Delaying aging: After dehydration, plums have a very high dietary fiber content and can be used to help regulate the function of the digestive system. They also contain a variety of antioxidants and have the effect of delaying aging.
5. Improving anemia: Plums are rich in vitamin B12 and can be used to treat and prevent vitamin B12 deficiency. Moreover, vitamin B12 has the effect of promoting the regeneration of hemoglobin, so moderate consumption is of great benefit to people with anemia.