Audit expert: Li Guangwang
Director of the Department of Natural Education of Beijing Children's Palace, Senior Teacher
I don't know if you've noticed: the fruit has become sweeter in recent years.
This finding is not unfounded: in the case of watermelon, data from a 2009 study showed that the total sugar content of seedless watermelon varied between 6.9% and 9.8%. In 2021, the average sugar content of common watermelon varieties is 9%, and the sugar content of the sweetest variety "Quanmei 2K" has reached 13.5%.
Image source: Red China
The sweeter the fruit is, the more delicious it is, but the increasing sweetness is also worrying.
1. Why are fruits getting sweeter and sweeter?
"Strawberry with cream", "watermelon with rock sugar", "Sunshine Rose", ...... The names of these fruits are often appetizing and show off their "sweetness".
More and more improved varieties of fruits are selling with "sweetness", and the "sweetness" in human genes is being satisfied by modern technology, so how do fruit farmers and modern technology achieve this?
01
Fruits also need to be "domesticated"
As we all know, many domestic animals are domesticated from wild animals, and fruits are also domesticated from wild plants to crops.
If you have ever watched "Lychee in Chang'an", you will find that from ancient times to the present, human beings have not stopped domesticating and selecting fruit varieties. From more than 400 varieties with different flavors in the early years, to the general trend of competing for "sweetness" today, the concubines who are not sweet enough have fallen into the bottom of the contempt chain, and the more sour black leaves have even disappeared from the market and have become inferior raw materials for canned lychees.
Image source: Xiaohongshu
Another example is Apple. The results of the research of the team at Dalhousie University in Canada showed that cultivated apples are 3.6 times heavier and 43% less acidic than wild apples. In addition, cultivated apples have a 68% lower phenolic content than wild apples, and phenolic compounds produce a bitter taste, meaning that today's apples taste much less bitter than their ancestors.
02
Genetically improved
The hybrid rice cultivated by Grandpa Yuan Longping keeps us away from the problem of hunger, and this scientific achievement is inseparable from the improvement and influence of crop genes.
We always say that agriculture belongs to "watching the sky and eating", but the quality and stability of crop harvest are not only related to the fluctuation of market prices, but also affect farmers' income. With the application of modern technology, agricultural producers can use new technologies for gene editing and breeding, resulting in sweeter fruit varieties. By studying the genome of fruits, scientists can understand the composition and nutritional value of fruits, and improve the sweetness and taste of fruits through gene editing technology.
Image source: Xinhua News Agency
At the same time, because of the advantages of improved varieties, farmers are choosing the same varieties for planting, which in turn affects the varieties of fruit we can buy. Before 2015, the market share of Zhangji strawberry was still relatively high, but after that, Hongyan strawberry began to dominate in the supermarket, because it has a very good comprehensive character, a certain hardness, and at the same time, the aroma, sugar-acid ratio are more appropriate, easy to manage, and the quality is relatively stable.
This dessert is simply a work of art, you must learn, and taking pictures is also a first-class good-looking der~
03
Technology helps farming
"Technology and hard work" has become synonymous with questioning food safety, but if you want to grow high-quality fruits in modern agriculture, technology is an indispensable driving force.
Cultivation management has become more refined, and the flavor substances of fruits can be accumulated more abundantly through reasonable water and fertilizer management and meticulous light and temperature control in the stage of fruit glycemic raising.
Image source: Xinhuanet
For example, many friends know that light is very important for the improvement of the sweetness of fruits, so in order to further improve the sweetness of some fruits, the fill light will be turned on in the orchard at night, and the light time will be extended, and the sweetness of the fruit will be improved. In addition to these, new research has also contributed to the sweetness of fruits, such as the discovery that applying a sucrose solution to leaves can effectively increase the sweetness of lychee, longan and mango. Therefore, many delicious fruits now have "science and technology and hard work" derived from scientific research achievements.
Is "Pure Sweet Wind" Fruit Still a Health Messenger?
For a long time, in the minds of most people, "eating more fruit = health", it is not surprising that this mindset has arisen:
Five editions of the Dietary Guidelines for Chinese Residents have been published, and except for the first edition in 1989, the remaining four editions have put forward the recommendation of "eating more vegetables and fruits". The latest version is the "Dietary Guidelines for Chinese Residents (2022)", the third of its eight guidelines for a balanced diet is "eat more vegetables and fruits, milk, whole grains, and soybeans", and the specific advice for fruits is "eat fruits every day, ensure the daily intake of 200~350g of fresh fruits, and fruit juice cannot replace fresh fruits".
Image source: People's Daily
With the continuous improvement of the sweetness of fruits, a question has gradually emerged, that is, is the sweetened fruit still healthy?
In 2018, the caretakers of the Melbourne Zoo in Australia made a new rule: animals are no longer allowed to eat fruit, not even bananas, which monkeys love to eat. Because the fruit-loving red pandas and primates have not only gained weight, but also had decayed teeth, the chief veterinarian at Melbourne Zoo believes the problem lies in the ever-sweetening artificially grown fruit.
But for humans, sweetened fruits do not cause a blood sugar crisis. Although fruits contain more sugar, there is more water, and the water content of many fruits is more than 80%, and the sugar in the fruit itself is wrapped in cells, plus it is rich in dietary fiber, etc., which takes a long time to digest into the bloodstream after eating, so it will not produce large blood sugar fluctuations in a short period of time.
Image source: pixabay
But if you turn fruit into juice, it's a different story. In 2013, researchers analyzed 100,000 servings of health data collected between 1986 and 2009 and found that juice intake was positively associated with an increased risk of type 2 diabetes. Conversely, according to pooled analysis, consuming a variety of whole fruits three times a week reduced the risk of type 2 diabetes by about 7% on average. Therefore, eating more fruits still has more benefits than disadvantages for the body.
Through observation, we can find an interesting phenomenon, that is, the sweetness of the fruit is linked to the price, which explains the question of many people, that is, "where did all those simple fruits go in childhood" - they are eliminated from the market because they are not sweet enough.
At present, we can still say that fruit is a healthy food, but if we love sweets more and more, maybe one day with the help of the food industry, fruit will also usher in a day when it is no longer healthy.