[Fact check] Misunderstanding and truth about tangerines and strawberries that people eat a lot these days.

[Open Radio YTN]

■ Broadcast: YTN Radio FM 94.5 (20:20-21:00)
■ Air date: December 21, 2024 (Saturday)
■ Host: announcer Choi Hwi
■ Bold: Selected number fact checker

* The text below may differ from the actual broadcast content, so please check the broadcast for more accurate information.

◇ Announcer Choi Hwi (hereinafter referred to as Choi Hwi): It's a fact-check time to point out false suspicious information that needs to be checked. Let's meet Cho Sun-soo's fact checker on the phone. Hello?

◆ Fact checker of Sun Jung-soo (hereinafter, Sun Jung-soo): Yes, hello.

◇ Choi Hwi: Yes. Today's fact check topic is various information about tangerines and strawberries. Tangerines and strawberries are in season. There are a lot of confusing information about tangerines and strawberries. Let's have a time to point out one by one today. What's the first topic?

◆ Selection number: Yes. It's about rubbing tangerines makes it sweeter. In fact, there are a lot of people who rub tangerines for a long time before eating them.

◇ [CHOI] That's right.

◆ Cho Sun-soo: There are a lot of stories about how to eat tangerines more deliciously if you search on the Internet. There are a lot of blogs written by netizens personally to articles from large credible media companies. Some articles provide a pretty plausible basis. When a tangerine is shaken or thrown, a component called ethylene is secreted in this process, which induces the ripening of tangerines and increases sugar content by 20%, which actually strengthens the sweetness of tangerines. In other places, it is said that rubbing tangerines causes tangerine grains to burst little by little, and organic acids that give off a sour taste spread throughout the tangerine, making the taste more evenly.

◇ Choi Hwi: From what you just told me, it looks very scientific and convincing. But I think they'll say it's not true. How is it?

◆ Cho Sun-soo: Yes, that's right. That's not true. The Citrus Research Institute of the Institute of Horticultural Science of the Rural Development Administration has already explained in a press release in 2021 that there is no basis for this myth. This is what the lab says. "When you say you eat tangerines by hand, the time you actually rub them is very short, so it's hard to say that this changes certain ingredients and makes a difference in taste." ’ I already revealed it like this. And there are also no scientifically proven findings. ’ That's what they say. I've traced the source of why this story spread. The oldest content searched in articles is a report by Dong-A Science in September 2012. The title is "How to eat Chuseok fruit deliciously." "Sharp persimmon, hit me! Grill apples! Sprinkle salt on your stomach! ’ I say this through an article with this title. The more ethylene is secreted, the sweeter the persimmon, and more ethylene is secreted when the persimmon is impacted. It means that if you hit it in moderation, it will be sweet. Tangerines can have similar effects. ’ I wrote it like this. Since then, based on this article, the myth that rubbing tangerines increases sugar content seems to have begun to spread. We also looked for the part that ethylene increases the sugar content of tangerines by 20%. In November 2015, KBS reported '[Knock! Reporter Honey! Info] From pulp to skin...Enjoy 200% of tangerines! ’ It's the first time I've ever been mentioned in an article like this. An expert who appeared in the report said, "When tangerines are stressed, their sugar content tends to rise due to the effects of ethylene. There is a research report that the sugar content increases by about 20% compared to just raw tangerines because they defend themselves when an attack comes from outside. ’ That's what I'm saying. I contacted this expert directly and asked for the source of the research report mentioned here, but I couldn't find it. The expert said, "The interview is old, so I don't remember it and there is no material left related to it. ’ That's the answer. "However, I feel a heavy responsibility for not thoroughly verifying the script written by the writer during the interview process." ’ That's what I said.

◇ [Choi Hwi] But I also feel that. In fact, there are many people who feel that tangerines become sweeter if you rub them and eat them.

◆ Number of selections: Yes. It's because of the temperature. The temperature at which the sweetness is best felt is 30 to 40 degrees, and it is said that the sweetness is most strongly felt when it is close to body temperature. However, it is said that in the process of hand-mixing tangerines, the cold tangerine warms to the point that it is similar to body temperature, and the sweetness is better felt. But how long does it have to be rubbed for the tangerine in the refrigerator to be warm enough to be similar to body temperature? So there are people who grill tangerines and eat them. In fact, grilling tangerines is said to be a good way to feel this sweetness. Therefore, it is said that some of the moisture evaporates during the baking process, and the density per volume increases, and you can experience more sweetness. At home, you can easily enjoy it by baking it in an oven or air fryer or heating it in a microwave for about 20 seconds and 30 seconds.

◇ Choi Hwi: It's not because you're rubbing tangerines, it's because of the warm warmth passed down by your hands as you cast them.

◆ [Cho Jong-soo] Yes, that's right.

◇ Choi Hwi: Yes. Let's move on to the next topic. Tangerines are winter fruits. Isn't this true?

◆ Selection number: It was generally judged to be true. In the past, tangerines were definitely winter fruits. In the Joseon Dynasty, there was a record that a Jeju pastor offered tangerines to the king during the winter solstice. But these days, you can taste tangerines all year round. Onju Persimmon will be on the market from October to February, the variety of golden incense will be on the market in late November, the red incense will be on the market in January, Hallabong and Cheonhyehyang in February, and the Kara incense will be on the market in May. House citrus will be shipped from May to September. So if you look at the calendar that writes down the citrus shipment period, the calendar is empty only in late September of the year. There are also people who know that tangerines grow only in Jeju. Tangerines are already being grown nationwide in Gyeonggi-do and Gangwon-do. However, it is said that Yokjido Island in Tongyeong-si, Gyeongsangnam-do, and Soan Island in Wando-gun, Jeollanam-do are also cultivated in some of the southern regions. However, if the worst-case scenario is applied with climate change, it is observed that open-field citrus can be grown in coastal areas of Gangwon-do in 2050.

◇ [Choi Hwi] I see. Then how about this? If you peel the tangerine, you can see white fiber, but you have to eat it. ’ Or 'don't eat'. There are conflicting stories.

◆ [Voiceover] The white thread that forms between the fruit and the outer shell of the citrus is called albedo in English. In oriental medicine, it's called galak by using the letter 'to intertwine'. But this doesn't appear in the standard Korean dictionary. This galak has no special taste and has a strong texture. So, some people feel that if there are too many galacs attached to the fruit, it is messy, and some people take out all the galacs carefully when eating tangerines.

◇ Choi HW: I take everything off and eat it too. The texture is tough for some reason.

◆ Sun Jung-soo: But this silica is said to contain a lot of pectin. This pectin is said to play a role in strengthening the intestine by protecting beneficial bacteria in the intestine. It is also said that the dietary fiber contained in silica helps improve constipation. Constipation is caused by decreased peristaltic movement of the large intestine, and it is said that if you eat silica, which is high in dietary fiber, you can actively exercise your intestines. In addition, a component called hespheridine increases the elasticity of blood vessels, preventing blood vessel diseases, and has anti-inflammatory and antibacterial effects. The Rural Development Administration talks about this silak. Unless you feel uncomfortable with the tough texture of galak, you don't have to take it off. Citrus fruits, as well as silica and tangerine peel, contain vitamins and hisperidine, which helps strengthen immunity. ’ I'm revealing it like this.

◇ Choi Hwi: From now on, I'll just eat this white fiber galak without taking it off. This time, we will look at another winter fruit strawberry. The first topic to look at is 'Don't take off with a strawberry top knife. It's '. I think we need to find out the context of this.

◆ Selection number: Health Chosun, a health medium, said in January 2021 that 'Strawberry top... Do you take it off with your hands? Do you take it off with a knife? ’ I published an article with this title. If you move the content of the article a little bit, it looks like this. "You have to pay attention to how to remove the top when you're handling it so that you can get enough nutrients." Strawberry fruits receive nutrients from stems and have the highest concentration of nutrients such as vitamins near the top. Therefore, it is effective to remove the top by hand because nutrients are greatly reduced if the white part around the top is cut out with a knife. ’ The article is mentioning it like this. The article published on the Internet did not specify any grounds. However, the title of the reference book is written in small letters on the Health Chosun website. So I looked up this book. It's a book published by Health Chosun's publishing brand. This is a translation that was published by the Ministry of Nutrition at a university hospital in Japan. It tells you how to cook food without loss of nutrients. It also boasts that it is a bestseller that sold 250,000 copies, but there was a lot of discomfort left to believe after checking up to this point.

◇ Choi Hwi: So you checked with the expert yourself?

◆ [Voiceover] Yes, that's right. There is a national vegetable research institute under the Rural Development Administration called the National Horticultural Research Institute. I checked it here. The Institute of Science said this. Strawberries are colored and mature from the end of the fruit. Nutrient content such as anthocyanin, carbohydrates, organic acids, and vitamins increases in the maturation stage when fruits are colored red than in the white maturation stage. Therefore, it is difficult to find evidence that white pulp near the tip has more nutrients. ’ This is the answer. Strawberry nutrients such as vitamins increase in content as they ripen red. Moisture and nutrients will be supplied along the stem, but the content of nutrients will be determined by the maturity of the flesh. There is a paper published by the National Institute of Horticultural Science in 2013 called "Changes in fruit quality and antioxidant activity according to maturity, storage temperature and storage period of strawberry varieties." According to the paper, the content of strawberry anthocyanin in the giant and western varieties, which were only 50% colored immediately after harvest, was as low as 33% and 42% of the 100% colored fruits. Therefore, there is no basis for considering that the white part close to the stem is rich in nutrients.

◇ Choi Hwi: Yes. We looked into interesting common sense about tangerines and strawberries. I hope you eat a lot of tangerines and strawberries this winter and have a refreshing and sweet end of the year. Thank you for your words today. Thank you.

◆ Cho Sun-soo: Yes, thank you.

◇ We've been with fact checker Cho Sun-soo.