Keep warm cups of tea to make heavy metals? Stainless steel is not so vulnerable.

Original title: Keep warm cups of tea to make heavy metals? Stainless steel is not so vulnerable
"people to middle-life have three treasures, the big moth insulation cup." After the winter, the insulation cup has become standard for many middle-aged people, and even some Buddhist youth have brought up the insulation cup. However, rumors that stainless steel insulation cups make tea and bubbly will cause heavy metals to dissolve into chronic poisoning, making many people uneasy when using insulation cups. Is it really that dangerous to drink hot tea every day?
With compliance insulation cup tea will not be poisoned
insulation cup tea will be poisoned, the reason for the insulation cup tea will produce tea scale, many people worry that tea scale long-term attachment to the stainless steel inner wall, will corrode stainless steel, resulting in stainless steel in the heavy metal dissolved, so that people chronic poisoning. After the tea was shot, radon and carbonated beverages were added to the blacklist of stainless steel insulation cups.
In this regard, Shenyang University of Technology School of Materials Science and Engineering Professor Ren Yibin said with a smile: stainless steel can not be so "vulnerable", only steel containing more than 13% of the chrome element can afford the name of stainless steel, alloying chromium can ensure the formation of the stainless steel surface passivation film, play a protective role in the stainless steel substation. In the GB9684-2011 national food safety standards, but also for food stainless steel materials have clear requirements. In addition to chromium, in stainless steel, alloying elements such as nickel, vanadium, manganese, copper, nitrogen and vanadium are added to improve the physical and corrosion resistance of stainless steel, but lead, cadmium and arsenic are strictly restricted as harmful impurities in stainless steel.
", however, stainless steel is not 'King Kong is not bad', in the face of acid, alkali, salt and other corrosive environment, corrosion can still occur, and lead to the dissolution of some alloying elements. Ren Yibin introduced, so the national standard GB9684-2011 also focused on the requirements of lead, chromium, nickel, cadmium and arsenic solubility limit, testing conditions are almost impossible to encounter in daily life harsh conditions, need to boil in 4% concentration of acetic acid for 30 minutes, at room temperature after 24 hours after analysis of the metal content, stainless steelware of various alloy elements are dissolved less than 0.5 mg / square meters.
Wang Hao, an associate professor at Tianjin University of Science and Technology's School of Food, said that in the field of food science, the common saying is "can not put aside the dose to say toxicity", such as tea, dates, carbonated beverages, although itself has acidity and alkalinity, but very weak, not to mention tea scale, even if a few days in a row, for the standard stainless steel cup, there is no need to worry about the dissolution of alloy elements. Even if trace amounts of alloying elements are corroded and dissolved, the alloying elements such as chromium, nickel, manganese and vanadium in stainless steel are essential trace elements of our human body and will not affect our health.
it is not reliable to rely on magnets to select the insulation cup
."Although stainless steel insulation cups are not as fragile as we think, when consumers choose insulation cups, be sure to choose stainless steel insulation cups for food utensils that meet quality standards." Ren Ibin reminds everyone.
On the e-commerce platform, click on some well-known brands of insulation cup specifications and packaging menu, the material inside will be marked 316, 304 stainless steel or other types of stainless steel grade, this string of figures let consumers a little confused. Some consumers, through stainless steel whether magnetic to distinguish the quality of the material.
to this Ibin introduction, according to the national standard GB9684 regulations, tableware stainless steel materials include Austrin stainless steel, Austrin-ferrine type two-phase stainless steel, ferrel type stainless steel and so on. One of the biggest differences between the three stainless steels, like their names, is magnetism. Only Aust steel has no magnetism, and the other two are commonly known as "rust-free iron". The price of Austrogen stainless steel is generally higher than that of the 12th. In addition, aust steel also has many kinds, the price difference is large. The main alloy elements of 304 and 316 with higher prices are iron, chromium and nickel, but the proportion of chromium and nickel is different. Among them, nickel element is a relatively expensive alloy element, the main role is to ensure the stability of stainless steel Austen tissue and performance. There is also low nickel (nickel-saving) containing manganese Aust steel, due to the use of manganese and nitrogen instead of part of nickel to stabilize austranic tissue, the price is relatively cheap, but performance and safety is not poor.
" above said these types of stainless steel, as long as the quality standards are met, its use safety is basically no problem. And formal manufacturers and brands, will be marked in the label stainless steel grade or chemical content. Ren Yibin specifically reminded consumers that people allergic to metal elements, must be marked according to the stainless steel grade online to inquire about the corresponding stainless steel specific ingredients. For example, nickel allergy patients should not choose 304 stainless steel products, while patients allergic to manganese do not choose low nickel containing manganese stainless steel products.
steel insulation cup to make tea is detrimental to the taste of
."Insulation cups made of stainless steel are not toxic, but prolonged high temperatures can affect the nutrition and taste of some foods." Wang Hao introduced, for example, insulation cup of tea, will affect the taste of tea. That's because tea contains tea polyphenols, fennel, aromatic substances, amino acids and multivitamins and other substances, when using boiling water in teapots or ordinary glass tea, tea in the active substances and flavor substances will soon dissolve, tea fragrance. And with stainless steel insulation cup tea will continue to keep warm environment, equivalent to the use of high temperature water to continue to cook tea, long-term high temperature, will make tea polyphenols dissolved extremely fully, while the active substance and aromatic substances are destroyed by heat, resulting in the quality of tea soup will also be destroyed, tea soup color thick, dark color, bitter taste.
for high-protein drinks such as soy milk and milk, it is also not recommended to use stainless steel insulation cups. This is because bacteria multiply at the right temperature and can only be stored at sterilization or low temperatures (slowing corruption and germs). Soy milk, milk and other nutrients, stored at the right temperature for a long time, microorganisms will multiply in large numbers. Soy milk, milk once long bacteria, will soon acid defeat, decay, appearance of floc-like, tofu brain-like, after consumption will lead to diarrhea and so on. Therefore, for this type of drink, it is best to drink within 3 hours. If you want soy milk and milk to stay longer, you must first soak the insulation cup with boiling water and wash it, killing any bacteria that may be present in it, and then pour in soy milk and milk.
For middle-age people's favorite radon, Wang Hao also does not recommend the use of insulation cup long-term brewing: "The stainless steel insulation cup brewing will not produce harmful substances, but hot water bubble, if the temperature of hot water exceeds 80 degrees Celsius, and for a long time soaked in high temperature water, then many of the vitamins and other nutrients in the moth will be lost." And with bubble water, the medicinal effect can not be fully played out. Due to the influence of water temperature, immersion time and other factors, only some medicinal ingredients can be released into water or soup. "
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