Eating preserved eggs won’t lead poisoning, it’s actually more nutritious than you think.
Original Gao Bowen Lilac Life Research Institute is included in the topic # So it is # 9# Food 14.
Speaking of preserved eggs, there are few Chinese who don’t like them.
But in foreign countries, it is called "Devil’s Egg", and it is ranked as the first of "10 China foods that foreigners can’t accept most" by CNN.
Even in Italy, Chinese people made the news because they were caught selling preserved eggs, because the local police thought preserved eggs were "unfit for human consumption".
Image source: Sina Weibo
Say preserved eggs are not suitable for human consumption?
Obviously, they don’t understand.
In China, this dark guy has conquered the taste buds of thousands of gourmets, and unlocked various ways to eat: preserved eggs and tofu, a classic appetizing cold dish, preserved peppers and eggs, which are popular in the southwest, preserved eggs and lean porridge, preserved eggs and vegetables in soup, which Guangfu especially loves … From south to north, preserved eggs are almost everywhere.
Image source: Station Cool Hailuo
However, whenever we end up with preserved eggs and are ready to eat, someone always says in our ear:
Eating preserved eggs will lead poisoning!
There are many harmful substances in preserved eggs.
Eating preserved eggs is risky.
……
But in fact-
Preserved eggs from regular manufacturers
Safe and reliable
—
Preserved eggs are also called "preserved eggs" and "metamorphosed eggs" in some areas.
Lead oxide is needed in traditional preserved eggs, mainly to block the small holes in the eggshell and prevent alkali from further infiltrating and melting the egg white. This operation will inevitably make the lead content of preserved eggs exceed the standard.
But now, most of the preserved eggs of regular manufacturers have adopted the "lead-free process." The lead content can be controlled below 0.5 mg/kg stipulated by the state.
Image source: Station Cool Hailuo
However, people may wonder why preserved eggs with "lead-free technology" may still contain lead.
This is because the fresh eggs themselves and impurities of metal additives may contain trace amounts of lead. The limit of lead in legally preserved eggs in the market is actually similar to candy, chocolate, eight-treasure porridge and tofu that we eat every day. This dose of lead will not have any impact on health, so there is no need to worry.
In addition, there are many black spots on eggshells, which are not necessarily high in lead. The black spots on eggshells are actually the deposits after the chemical reaction of "processing AIDS", which are affected by many factors such as manufacturing temperature and curing time. Just because there are many black spots on the eggshell doesn’t mean that its lead content exceeds the standard.
Image source: Station Cool Hailuo
Some people are worried about the color of preserved eggs. It’s dark. Is it poisonous?
But in fact, the black of preserved eggs is normal. Preserved eggs went through a "protein decomposition and recombination" during the curing process, and finally browned to produce dark substances, which did not produce harmful substances.
Moreover, preserved eggs are not only dark, but also yellow. This mainly depends on the variety and production technology of fresh eggs. At present, preserved eggs in China are mostly made of duck eggs, but they are also made of eggs and quail eggs. Although they are of different colors and sizes, their delicacies are always strikingly similar.
Dark preserved eggs
Huang Tongtong’s preserved eggs
Image source: Station Cool Hailuo
Seeing this, everyone should know that preserved eggs purchased under formal channels are safe and reliable and can be eaten with confidence.
However, there are still people who are worried: when preserved eggs are salted, is there no nutrition at all!
No, actually-
Compared with fresh eggs
The nutritional value of preserved eggs is not bad.
—
As a qualified preserved egg, although protein has degenerated, it has not lost too much nutrients.
Comparison of Nutrients among Eggs, Duck Eggs and Preserved Eggs
name
protein
fat
(hen’s) egg
12.2
10.5
duck’s egg
12.7
13.8
100-year egg
13.8
13.5
* Data source: China Food Composition Table 4th Edition, unit: mg/100g).
Not only that, protein in preserved eggs is more conducive to human absorption. Protein was hydrolyzed initially in the curing process, which relatively reduced the digestive pressure.
Preserved eggs are delicious
But pay attention to this point.
—
The sodium content of preserved eggs is not low
The sodium content of preserved eggs is 542 mg/100 g, which is almost five times that of fresh duck eggs.
We use about 2 preserved eggs for each cold salad, and the peeling is about 120 grams. Just eating preserved eggs, you almost ate 656 mg of sodium, which is close to 1/3 of the recommended daily intake in the Dietary Guidelines for China Residents.
Image source: Station Cool Hailuo
Moreover, preserved eggs are not salty to eat. For example, we often use a lot of salt and soy sauce to flavor preserved eggs with tofu and pepper, so we eat a lot of "sodium" invisibly.
Eating too much sodium will increase the risk of diseases such as calcium loss and hypertension.
If you eat preserved eggs, you still have to restrain yourself.
Cooperation expert Gao Bowen
Practitioners in food safety testing industry
Scientific audit is unintentional.
Doctor of Food Engineering, Department of Agriculture and Biology, Purdue University, USA
Content planning Kiki
Please contact gusiqi@dxy.cn for cooperation.
references
[1] Zhang Lili, Liu Guoqing, Wang Aimin, Zong Kai, Qian Xiaoyong. Pickled lead-free preserved eggs with different metal salt combinations and determination of their metal content [J]. Food Industry Science and Technology, 2010,31(02):189-192.
Tang Lijun, Deng Zeyuan, Fan Yawei. GC analysis of yolk lipid changes of processed duck eggs [J]. Food Science, 2006(12):588-590.
[3] Zhang Chenping, Liu Huiping, Zhao Fan, Liu Xiaoqing, Xu Jiaojiao, Wang Yu. Changes of yolk lipids in preserved eggs during decompression [J]. Food Science and Technology, 2015,40(03):61-64.
[4] Yan Hua, Tang Shangwen. Study on the excessive copper content in preserved eggs [J]. Jiangsu Agricultural Sciences, 2012,40(06):292-293.
[5] Wu Yongning, Li Xiaowei. The fourth total diet study in China [M]. Chemical Industry Press, 2015.
[6] Yang Yuexin. China Food Composition Table [M]. Beijing Medical University Press, 2005.
[7] Yan Hua, Shen Xiurong. Effects of processing technology on the quality and heavy metal content of preserved eggs [J]. Agricultural products processing, 2013.
Sun Jing, Cai Ying, Du Jinping. Effects of different metal additives on the formation of eggshell spots [J]. Processing of agricultural products (below), 2013.
[9] Jiang Aimin, Zhang Fuxin. Reasons for the formation of Huang Ji’s metamorphic eggs and solutions [J]. Meat Research, 1991(03):23-25.
[10] Longmen, Song Ye, Du Qingfei, et al. Gel characteristics and color changes of protein in preserved eggs [J]. Food Science, 2016, v.37; No.520(03):94-99.
[11] Hou Dajun, Li Hongjun. Effect of alkali treatment on physical quality of flavored preserved eggs [J]. Food Industry Science and Technology, 2008(5):119-121.
[12] Zhou Zan. Research and analysis of preserved egg processing technology [J]. Agricultural products processing (4): 74-75.
[13] Li Shuqing, Huang Peng, Wang Qingyu. Study on the mechanism of yolk color change in preserved eggs during processing and storage [J]. Food Science, 1992(02):20-24.
[14] Chen Zhangyi. Study on the formation mechanism of preserved egg protein gel induced by strong alkali [D]. Nanchang University .2015
Ma Li, Bai Qi, Xie Lin, Su Zhao. Study on the crystal structure of "Songhua" of preserved eggs [J]. Journal of Sichuan University of Technology (1):48-50.
[16] General Administration of Quality Supervision, Inspection and Quarantine, National Standardization Administration Committee. Preserved eggs: GB/T 9694-2014[S],2014.
[17] National Health and Family Planning Commission, china food and drug administration. National Standard for Food Safety-Limits of Pollutants in Food: GB 2762-2017[S],2017.
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