In many people's minds, the fresher the fruit, the better it tastes. Therefore, fruit bought home should be eaten as soon as possible. However, Professor Feng Shuangqing, an expert on fruit and vegetable storage from the College of Food Science and Nutritional Engineering at China Agricultural University, told a reporter from the Life Times that some fruits are not at their best when they are first bought or picked. This is because some fruits become completely soft very quickly once they ripen, making them impossible to transport and store. Therefore, they must be picked in a "hard" state before they are fully ripe to be safely transported to the supermarket. Compared to other fruits, these fruits require a "post-ripening" process.
Kiwi. Gently press the ends of the kiwi with your fingertip. If it no longer feels hard, the pressed area shows slight deformation but is not too soft, this is the best state for eating. For kiwis, there's a saying among farmers: "It gets soft in 3 days, rots in 7, and half will be spoiled in half a month." Therefore, when buying, choose kiwis that are firm and have no mechanical damage. However, hard kiwis are not tasty; their sugar content is low, the fruit is sour and astringent, and it can feel irritating to the mouth because it contains a large amount of proteases that break down the proteins of the tongue and oral mucosa, causing discomfort. At room temperature, kiwis generally become soft in about 3 days, reaching the best state for consumption. To speed up ripening, you can place the kiwi with a ripe banana; the natural ripening gas "ethylene" emitted by the ripe fruit will "infect" the kiwi and promote its ripening. If you want to store it longer, you can put the kiwi in the refrigerator, as the low temperature can slow down its ripening process.
Banana. When the peel is completely yellow and it has a rich fruity aroma, the banana is at its best. However, bananas turn black easily, so you can choose a slightly unripe one when buying. Generally, bananas with a "green shoulder" can be eaten in 1-2 days when stored at room temperature. To accelerate ripening, you can place them with a ripe apple. If you want to store them longer, you can hang them to ensure good ventilation, which allows the produced ethylene to disperse with the wind and slow down the aging of the bananas.
South Pear. Gently press the South Pear with your finger; if you can feel it is elastic and it smells strongly of wine, this is the best time to eat it. The South Pear has obvious "post-ripening" characteristics; it needs more than a week of natural fermentation after picking to reach its best state. It should be noted that when storing South Pears, the plastic bag should not be tied too tightly; a "breathing opening" should be left for the fruit to maintain its "activity." Placing the South Pear in the refrigerator can slow down its respiration and keep it fresh.
Persimmon. "Soft" and "not astringent" are important signs of a ripe persimmon, but such persimmons are not suitable for picking, transportation, and storage. Unripe persimmons contain a large amount of soluble tannins, which have a strong astringent effect. They can stimulate the nerve endings in the mouth, causing a "astringent" sensation. If a raw persimmon is isolated from the air, acetaldehyde, acetone, and other organic substances will be produced inside. These substances can convert the water-soluble tannins into water-insoluble ones, making the persimmon non-astringent to eat. Therefore, place raw persimmons in a plastic bag, tie the opening tightly, and after a few days, they will be de-astringent and become fragrant and sweet.
Avocado. Squeeze the surface of the avocado with your hand; if it feels elastic and the flesh is firm, it indicates that the avocado is ripe. The more dark brown spots on the green surface, the riper the avocado. However, if the peel is mostly covered with light and dark brown spots, it is not recommended to buy it, as it might be overripe and spoiled. If you are not eating it on the same day, it is advisable to buy a relatively unripe avocado. Such fruit will naturally ripen in 2-3 days at room temperature, and a ripe avocado can be stored in the refrigerator for about a week.