Many foods become heinous for just one “overnight”.
Overnight water, overnight tea, overnight vegetables, overnight watermelon…
This one, tsk tsk! Rumors are poisonous!
Are they really inedible? ! This one makes it clear!
Myth: Too much nitrite in overnight water can cause cancer.
Truth: Water is okay to drink overnight.
Overnight water does contain nitrite, but talking about toxicity in doses is hooliganism.
In my country’s drinking water hygiene standards, the nitrite content is specified as ≤1 mg/L[1]. Studies have found that after bottled water, purified water, and tap water are placed for 3 days (overnight many times), the nitrite is still in the safe range [2], and it is safe to drink.
What you should really pay attention to in overnight water is: cover the lid. If you don’t keep the lid on and don’t drink it, the water may be polluted, fall into dust, flying insects, and may exceed the limit of bacteria. .
(Source: soogif)
Rumor: Overnight tea is as poisonous as a snake, and even drinking it can cause cancer.
Truth: Overnight tea is okay.
According to the Beijing Nutrient Source Experiment [4], whether it is Pu’er tea or chrysanthemum tea, the nitrite content changes little after 12 hours and 24 hours, and both are less than 0.2 mg /L (in compliance with the safety limit standard <1 mg/L), Longjing is slightly higher but not more than 0.3 mg/L, and they will not cause cancer.
(Source: soogif)
As for why the overnight tea changes color, it is because the tea polyphenols in it are oxidized, and the tannic acid increases after being left for a long time, and the taste is worse, but it will not harm health.
Some people worry about the increase of bacteria in the overnight tea and have diarrhea after drinking it. In fact, as long as the tea itself is free from pathogenic bacteria such as Salmonella and Staphylococcus aureus, bacterial food poisoning is unlikely to occur.
Rumor: Overnight vegetables cannot be eaten, as eating too much will cause cancer.
Truth: You can eat it, remember to “put it in the refrigerator in time, and don’t leave any cold dishes left over.”
Zhejiang Ningbo Food Inspection Institute specially verified in 2019 that they made 30 home-cooked dishes and stored them at 4°C and 25°C for 0, 6, 12, and 24 hours, respectively[ 5].
(Source: soogif)
Experiments have shown that the nitrite content of various dishes stored at 4°C after 24 hours is the same as when it was just out of the pot, and it is less than the limit of nitrite stipulated by the state. 1/3 of the value [6], it will not cause cancer.
At 25°C, meat dishes are fine overnight, but nitrites in leafy vegetables will increase significantly, so it is best to eat them within 6 hours.
Also note: the second meal of the overnight dish must be fully heated (100 ℃ for more than 3 minutes), it is best to add some onion, ginger and garlic, seasoning and sterilization.
Rumor: You can’t eat watermelon overnight, and the bacteria in plastic wrap will multiply faster.
Truth: Watermelon can be eaten overnight, no problem if it is wrapped in plastic wrap and refrigerated.
In the past, most of the watermelon harm incidents that happened in the news were caused by the uncleanness of the watermelon cutting knife and the storage environment, and the large number of pathogenic bacteria in the watermelon.
(Source: soogif)
Researchers from the Fujian Academy of Agricultural Sciences have specially conducted experiments. They selected three varieties of watermelons, cut them, covered them with plastic wrap, and put them in the refrigerator (4°C) for 16 hours [7 ], and it was found that the total number of colonies of the overnight watermelon and fresh watermelon was similar, and it was safe to eat.
To ensure safety, clean the knife, watermelon, hands, and chopping board before cutting the watermelon. Cover the watermelon with air-permeable plastic wrap before refrigerating.
Myth: Overnight soaked fungus is poisonous.
Truth: Really can’t eat it.
Avoid soaking fungus and tremella overnight!
Foamed fungus, white fungus, fermented rice noodles, and starch products are easily contaminated by Pseudomonas cocoa, producing high-temperature-resistant rice yeast acid toxins at room temperature. People who eat it will not only have abdominal pain, bloating, diarrhea, nausea and vomiting, but excessive intake can lead to multiple organ failure and even death!
(Source: soogif)
It was initially identified as the culprit of the Heilongjiang sour soup poisoning incident (which resulted in 9 deaths).
Soak fungus and white fungus by yourself. Generally, it can be processed and eaten after soaking in cold water for 1~2 hours. If it is too late, it is better not to exceed 4 hours. If mucus is produced, the surface is sticky and smells bad, it is best to throw it away.
This is really unacceptable! Long time anger hurts!
Finally, I will send you four sentences “Don’t be angry”:
I am not angry when others are angry,
Out of breath, there is no one to replace.
If I’m angry, who’s going to be happy,
It’s frustrating and exhausting.
Contributing Author: Huang Yuanyuan| Registered Dietitian
Reviewer: Zuo Xiaoxia| Director, Department of Nutrition, Eighth Medical Center, PLA General Hospital
References
[1]GB5749-2006, Sanitation Standard for Drinking Water.
[2] Chen Ying, Xiao Yanjie, Liu Xiaolin. Changes of nitrite and nitrate content in drinking water after being boiled for different time [J]. Journal of Jinzhou Medical University, 2018, Vol.39 , Issue 6.
[3] Qin Pinzhang. Several opinions on revising the hygienic standards for the use of food additives nitrate and nitrite [J], Chinese Journal of Preventive Medicine, 2005, 6: 150-151.
[4] Overnight tea is as poisonous as a snake? CCTV experiment is still innocent [J], China Tea, 2014, 36(06): 23.
[5]http:https://py.zjol.com.cn/rdgz/201907/t20190724_10651911.shtml
Zhejiang Online “Overnight Vegetables Are Poisonous? Ningbo Food Inspection Institute uses 450 data to tell you the answer”.
[6]GB 2762-2005, Limits of Contaminants in Food.
[7] Lv Xin, Chen Lihua, Li Xiaolin, Liu Lanying, Huang Wei, Li Hren. Eating safety evaluation of fresh-cut watermelon after overnight refrigeration [J]. Fujian Agricultural Journal, 2018, 33(08):865-869.
*The content of this article is for the popularization of health knowledge and cannot be used as a specific diagnosis and treatment suggestion, nor can it replace the face-to-face consultation of a licensed physician, and is for reference only.
*The copyright of this article belongs to Tencent Medical Dictionary. Unauthorized reprinting by media is prohibited. Illegal reprinting will be investigated for legal responsibility according to law. Individuals are welcome to forward to the circle of friends.