As a must-have fruit for the Spring Festival, sugar oranges have recently become quite popular, and many people buy them at home one by one. But did you notice, many of the sugar oranges you bought have a hole in them! 
Source: Xiaohongshu @ Gaishi 嘤嘤猫 (Authorized) Is it normal for sugar oranges to have holes? Where do these holes come from? First of all, it is certain that the holes in the sugar orange are almost impossible to be caused by artificial cyclamate, etc., as rumors say. The reason is very simple, to inject cyclamate into sugar oranges one by one, this labor cost has to spend a lot! Tangerine (pseudonym), who is from Guilin, Guangxi, and has more than 800 sugar orange trees at home, told Yiyu that the price of sugar oranges from their production area is about two or three yuan a catty, and the cost is not as low as one dollar per catty as reported on the Internet. "Just picking a pound of sugar oranges after ripening costs 2 3 cents, plus the usual fertilizers, manual care, etc., are all costs; If you hire someone to give cyclamate to sugar oranges one by one, the cost will definitely be greatly increased, resulting in extremely low profits, and may even be reversed. "In addition, experiments have long proven that it is not realistic to add cyclamate to fruits. It can be beaten in, but cyclamate will destroy the peel and pulp of sugar oranges, speeding up the rate of decay. In the experiment, the fruits that were beaten with cyclamate basically spoiled in no more than three days, and they could not be eaten at all. If the fruit growers give cyclamate to the sugar oranges, it is estimated that they will all rot before they are sold. So where do these holes come from? In fact, there are many reasons for the creation of these holes. Some sugar oranges were "backstabbed" by the sugar orange tree before they were picked, and a hole was poked out by the thorns in the sugar orange tree. 
The sugar orange was poked by the thorns on the sugar orange tree丨Source: Xiaohongshu @ Watermelon Information Agency **Screenshot The thorns on the sugar orange tree can grow up to seven or eight centimeters at most, and this thorn can play a protective role for the sugar orange tree, and can also prevent the invasion of individual pests and diseases or prevent the loss of water and nutrients. However, not all sugar orange trees will have thorns, except for different strains (for example, golden autumn sugar orange trees do not grow thorns), if you apply too much fertilizer when planting sugar orange trees, such as nitrogen fertilizer, it is easy to make the tree grow thorns. Even if the sugar orange trees do not develop thorns that puncture the sugar oranges, these sugar oranges may "kill each other" after being picked. When sugar oranges are picked, they are not picked one by one with bare hands, but with scissors. Sometimes the fruit pedicle is cut very short, sometimes it is so long that even the leaves are left together. Tangerine told Yiyu that if the fruit of the sugar orange is not cut to the top of the sugar orange, then it will inevitably bump and collide during the mailing process, and the sugar orange may be poked by the fruit of other sugar oranges, and a hole will be left in the peel. 
The sugar orange that was punctured by the fruit of another sugar orange丨Source: Xiaohongshu @ Watermelon Information Agency **Screenshot The reason why the sugar orange is so easy to poke a hole out of the fruit pedicle is that in addition to the fact that the fruit pedicle is relatively hard, the main reason is that the peel of the sugar orange is thin and soft. Generally speaking, the average thickness of the peel of sugar orange is 2 mm and below, which is a very thin peel, you must know that the average thickness of the peel of sugar orange is about 2 4 mm, and the average thickness of the peel of Yichang orange is about 3 6 mm. The soft skin of sugar oranges is closely related to pectin. Sugar orange is a kind of citrus, citrus is a citrus plant of the Rutaceae family, the peel is rich in pectin, cellulose and essential oils and other substances, of which the pectin content is about 20%, and in the study published by Shi Yuefeng et al. in "Food Research and Development", the pectin extraction rate of sugar orange peel is 2674%, which indicates that the pectin content in the peel of sugar orange is relatively rich in citrus. And pectin plays a very important role in the process of softening the peel. Before the sugar orange is ripe, there will be a large amount of propectin in the peel, which is a non-water-soluble substance that combines with cellulose to make the sugar orange firm and brittle. With the gradual maturity of sugar oranges, under the action of protopectinase, protopectin and cellulose are separated, protopectin decreases, and soluble pectin in the cell wall of the peel increases, so that the cells lose their binding force, so that the cells are dispersed, and the texture of the peel gradually changes from hard to soft. As a result, the peel of sugar oranges, which are rich in pectin, becomes very soft when ripe, and because they are less than 2 mm thin, they are naturally easy to puncture the fruit pedicles. Some people may wonder why they don't just pull it off when picking sugar oranges, instead of cutting it with scissors to keep the stems, since the stalks of sugar oranges may hurt other sugar oranges? Some people think that the choice to keep the fruit stalks and even the leaves on the sugar oranges is to increase the weight of the sugar oranges and increase profits in disguise. But that's not the case. Tangerine told Yiyu that the fruit of sugar orange is hard, not as soft as strawberry, and you can pluck the fruit directly by hand. Moreover, the fruit pedicle of the sugar orange is very "strong" with the peel, and the sugar orange peel is relatively fragile, although the direct hard picking can tear off the sugar orange, it will also cause the skin on the top of the fruit to be torn, then the sugar orange will be "broken" and cannot be sold. 
The fruit pedicle of the sugar orange丨Source: On the other hand, keeping the fruit pedicle of the sugar orange can improve the freshness of the sugar orange to a certain extent. During storage, sugar oranges are prone to water loss, weight loss, skin texture changes, and even floating skin due to stomatal respiration, which are mainly closely related to moisture and pectin components. As an important part of sugar oranges, the fruit pedicle plays a key role in the preservation of water and nutrients in sugar oranges. A study by Southwest University proved that the respiration and transpiration of the whole fruit pedicle are the strongest, and the fruit pedicle is the main "gateway" for the exchange of water and nutrients between the fruit and the outside world. The results showed that the relative moisture content of citrus fruit peel decreased significantly during storage, and the water loss of citrus peel was aggravated by sessile treatment, and the relative moisture content of pedicle peel was significantly lower than that of normal fruit during the whole storage stage. In other words, by retaining the fruit pedicle, the sugar orange can look more moist and not wilt when it reaches the consumer. 
Changes in the relative moisture content of citrus fruit peel during storage丨Source: Reference [6] Correspondingly, the weight loss rate (the ratio of the weight lost to the initial weight of the fruit) of citrus fruits during storage increased significantly, and the weight loss rate of sessile fruits was higher than that of normal fruits from the early stage of storage, indicating that fruits without stalk lost their nutrients and water faster than normal fruits. During storage, the soluble pectin content of the pedicle-removed peel increased more significantly, and the content of protopectin decreased more significantly. As a result, sugar oranges without a stem will become soft and rotten faster. This suggests that retaining the fruit pedicle can stabilize the postharvest texture change of citrus. It maintains the change of pectin content by preventing water dispersion and loss, and achieves the effect of fruit preservation. In addition to preserving the fruit pedicle, there are many things to pay attention to when cutting sugar oranges. Tangerine told Yiyu that after the sugar orange is picked, it is easy to rot when it is sealed with water, but too much drying will also affect the quality of the sugar orange. Therefore, picking sugar oranges should be carried out on sunny or cloudy days as much as possible, and should not be picked under the scorching sun at noon, rainy days or when the dew on the trees is not dry in the morning, so as to avoid wilting or watery fruits. Moreover, during harvesting, care should also be taken not to bruise or cut the fruit, so as not to leave wounds and be infected with germs that may cause the fruit to rot and become moldy. When picking fruits, they should be handled with care, so as not to puncture the peel of the fruit and ensure that the appearance of the fruit is intact, because the incomplete appearance of sugar oranges is very affecting the fruit harvest. 
Source: Xiaohongshu @ is a juan'er note**Screenshot Tangerine also told Yi Yu that the most difficult thing to cut sugar oranges is to pick the sugar oranges at the top of the tree. As the age of the sugar orange tree increases, so does the height of the tree. Most of his family's fruit trees have been planted for more than 10 years, and the height of the trees is basically more than 2 meters, so it is very difficult to pick sugar oranges, so he can only use ladders or climb trees. In winter, when the weather is cold, the growers also cover each row of sugar orange trees with a film to prevent the sugar oranges from being frozen. Climbing to the top of a tree or standing on a ladder with a membrane on the one hand will feel very hot and breathing will not be smooth, on the other hand, people need to hold their heads up for a long time and get dizzy easily. 
Sugar orange trees covered with film丨Source: Xiaohongshu @ Xiao Tangerine (sugar orange version) (authorized) and, in order to avoid the sugar oranges picked from a high place from falling and breaking, fruit farmers must put them in the bucket or frame one by one by hand, which makes the picking efficiency very low. Looking at it this way, Guangxi's old table cutting sugar oranges can be described as well-intentioned. So when you see sugar oranges with holes, you can think about it differently, at least it shows that this batch of sugar oranges has done a good job of keeping them fresh when they are picked.