What is the deal with citrus deacidification and sweetening agents? Chen Xingzong explains for you
In the season when the tangerines turn red, everyone once again revisits this topic.
Should we really worry about the "deacidification and sweetening" of citrus? Let us set the answer aside for now; please read patiently through my humble views, and the answer will naturally emerge.
The Sweet-and-Sour Strategy of Seed Dispersal
Human taste buds have their own innate preferences. A study on the sense of taste in newborn infants once found that babies like sweet, savory, and a tiny hint of saltiness; they dislike bitter and sour.
Researchers reasoned that this should be an intuitive human response under continuous evolution. Observing the foods around us, we can indeed see that sweet represents rapidly absorbed calories, savory represents amino acids that can be quickly utilized, and salty represents minerals. Bitterness means plant alkaloids or immaturity, and sourness also represents immaturity or spoilage.
So it is destined: our innate DNA makes us have our likes and dislikes.
Therefore, it is only natural that people dislike sour citrus fruit and like sweet citrus. I believe the birds and beasts that go out to gather fruit must have the same likes and dislikes.
Having discussed the needs of animals, let us also look at the citrus's point of view. (Of course, this is prior research and human observation; surely no one interviewed the citrus's innermost thoughts.)
Citrus has no hands or feet to travel, so dispersing seeds will inevitably involve some strategies. Sourness and sweetness are precisely the manifestation of its scheming.
Why Is Citrus Sour?
That must be insufficient ripeness. The three words "insufficient ripeness" superficially mean the fruit is not ripe enough, but in essence mean the seeds are not ripe enough. Citrus actually wants to use sweet, beautiful fruit to lure gatherers to come pick the fruit, take a big bite of the flesh, and satisfyingly eject the seeds. Before there is enough time for leaf nutrients to flow back into the seeds, this fruit cannot leave the mother tree; they do not want some reckless fool to pick the fruit before the seeds are ripe and ruin the good thing. At this time, citrus will paint the rind with a low-key, dull coating, and the flesh will still be very sour, even astringent. This and the bitterness and astringency of sweet persimmon before ripening are scheming from the same mold.
Then Why Is Citrus Sweet?
Once the seeds are ripe enough, the citrus mother tree will begin to raise the sweetness and flavor of the flesh, dress the fruit in bright red finery, and release fruit fragrance. This is a proclamation to the world: the fruit is ripe, come quickly to pick it, and by the way help them disperse the seeds.
The sweetness of citrus is a gift trait thanking the seed dispersers, as well as the scheming of the citrus mother tree. Imagine, if after eating tangerines this year you got diarrhea or ate fruit that made the disperser very unhappy, who next year would still want to help them disperse seeds? Therefore, the mother tree will do its utmost to prepare the gift in the best possible condition, but this will consume a great deal of stored organic nutrients, squeezing out many other resources for normal operations, such as resistance to adversity, resistance to pests and diseases, storage, maintenance, and growth, all of which will be affected. In fact, it is a costly matter.
Fortunately, healthy fruit trees can allocate resources in the best possible way. But when foolish humans intervene and influence things, that is another matter.
Then Why Is Citrus Not Sweet Enough?
Sweetness definitely does not come from fertilizer (no one has ever seen ants carrying fertilizer in a fertilizer warehouse); sweetness comes from photosynthesis in the leaves. In the field experience I have seen, insufficient fruit sweetness is often caused by insufficient allocation of the organic nutrients that raise sweetness, too many fruits, insufficient photosynthesis conditions, weakened tree vigor, excessive nitrogen fertilizer uptake during the ripening period, large day-night temperature difference, soil adversity (acidification, shallow root system, poor aeration and drainage), pathological factors, insufficient time for nutrient input into the seeds....
Clever Yet Foolish Humans
In the survival strategies of fruit trees, reproduction is an important goal; therefore, making good use of and flexibly allocating resources to produce seeds is their lifelong duty. Humans understand their innate duty, so some people will, near the seed-ripening period, give the mother tree a bit of pressure and a bit of adversity. When the citrus mother tree senses adversity and pressure, in order to seize limited time and limited resources, it will strive to rapidly pour organic nutrients into the fruit and seeds, lest this building that is 80 percent complete be destroyed.
Such rapid allocation satisfies the manager's needs, and the fruit tree's original production and allocation are also disrupted. Such disruption requires more time to compensate for and correct, and the damage is considerable; the risk of damage to crops from pests or external factors rises sharply, and if the manager does not help in time, the citrus mother tree will inevitably decline, even die.
After understanding such principles, everyone should be able to imagine that in the past some people used a specific A sweetening agent (hereafter referred to as A, because there are similar substitutes for this type of substance on the market, which we do not name explicitly, lest someone again think himself clever), to rapidly create adversity for citrus and make the fruit quickly sweet and beautiful. Later it was discovered that A is harmful to the human body, and farmers further discovered that it causes great harm to citrus trees; clever farmers should not want to continue using it.
There are also methods now to raise fruit sweetness that are relatively milder and have little effect on consumers. Some people suppress excessive nitrogen uptake by increasing phosphorus and potassium, some use calcium and boron, some use water restriction, some use.... At present, many fertilizer products advertised for enhancing fruit sweetness in the later stage should not contain A.
It Is Time to Reflect!
In any case, all of the above demonstrates humanity's one-way, linear thinking of wanting fruit to be sweet and wanting to gain more market profit. Over time, the soil has changed, and the tree's survival and resource allocation methods have changed as well.
Therefore, I have always worked to promote B.C.S., and the simple old-timey bucket tangerine that simply restores the normal state of soil and crops can astonish everyone.
Should we not reflect on the thinking we have long taken for granted, treating wrong as right? Some people care about labor rights, some talk about animal welfare; in fact, very few people care about the issue of crop welfare, which is closely tied to our sustainable health and food safety.
Getting back to the point, should we really worry about the deacidification and sweetening of citrus? I suggest everyone not look for the answer here. Everyone should take responsibility for their own food and should go down to the fields to find farmers, walk around and look, and improve their own food and agriculture knowledge. Find a farmer you trust, and see whether his fruit trees are healthy. Is the bark glossy? Is the taste to your liking? In the past, A, which harmed both the human body and fruit trees, has been abandoned, and the non-A that has replaced it, although harmless to the human body, must also be given our attention and faced squarely.