Revealing the Health Risks of Dyed Food
Over 80,000 Bags of "Problem Steamed Buns"
According to an investigation by the Shanghai Public Security Bureau, Ye Weilu, the legal representative of the Shanghai Shenglu Food Co., Ltd. branch, Xu Jianming, the sales manager, and Luo Xunyun, Xu Shanbo, and Xu Dongsheng, three production workers, confessed that since January 2011, the company had illegally produced and sold 83,716 bags (4 buns per bag) of "problem steamed buns" containing the prohibited additive tartrazine, with a total value of over 200,000 RMB. The sales manager, Xu Jianming, was responsible for contacting and selling these "problem steamed buns" to 10 supermarkets in Shanghai, including Hualian, Lianhua, Diye Tiandian, Lotte Mart, Huinong, Leja Shopping Center Songjiang Store, Yurunfa Shopping Center, Jimaisheng, Wumei, and Ru Hai. Currently, the Shanghai Public Security Bureau has criminally detained the five suspects in accordance with the law.
So, what are dyed steamed buns? How can you identify them? What are the methods for identifying dyed steamed buns? Let's find out below.
Experts explain that corn is a coarse grain, and foods made from cornmeal have a coarse appearance and feel when pinched, and a somewhat rough texture in the mouth. However, some "corn steamed buns" on the market feel soft and smooth, and you can't taste the natural aroma of corn. Their color is also unnaturally yellow. These "corn steamed buns" most likely contain additives like dyes, with tartrazine being the primary one.
Identification Method: Tartrazine is a synthetic dye. China's regulations stipulate a very maximum usage limit for it in food processing, and excessive use is harmful to the health of consumers. Experts suggest that to determine if "corn products" have been adulterated with dye, you can soak a small sample in water. The filtered liquid from tartrazine-dyed "corn products" will turn yellow.
Using Toilet Paper to Identify Dyed Yellow Croaker
Some unscrupulous merchants dye yellow croaker (Nibea albiflora) to pass it off as yellow croaker (Pseudosciaena crocea). The dye used is often a chemical dye, such as "golden jade," which is harmful to health when consumed.
Identification Method: Wipe the fish with white toilet paper; a dyed fish will leave a distinct yellow stain on the paper. For frozen, block-dyed yellow croaker, the ice surface may sometimes appear yellow. You can also soak the fish in water for about 5 minutes; the water from a dyed fish may turn beer-colored.
How to identify if yellow croaker is fresh: Generally, a fresh yellow croaker has full, clear corneas, tightly closed gill covers with bright red gills, and transparent, odorless mucus. The flesh is firm and elastic, the head and tail are not bent, and any indentation from a finger press recovers immediately. The scales are complete and shiny, adhere tightly to the body, and are not easily脱落.
Dyed Mushrooms
Photo of shiitake mushrooms (top) and crab stick mushrooms (bottom) that glow under UV light
A counterfeit detector can be used to check for fluorescent mushrooms
Some unnaturally white mushrooms have appeared in vegetable wholesale markets and were found, upon testing, to be coated with fluorescent substances.
Fluorescent bleaching agents have a strong bleaching effect. When mushrooms are soaked in water containing fluorescent bleaching agents, they become whiter and brighter, extending their shelf life and maintaining their color. Once fluorescent substances are absorbed by the human body, they are not easily broken down, increasing the burden on the liver and raising the risk of cancer. Therefore, it is recommended that consumers choose mushrooms that have soil on them and are relatively dry. The surface of mushrooms is easily bruised, and the wounds can oxidize and turn brown, so brown mushrooms are actually their natural color.
Identification Method: Hold the mushroom close to a counterfeit detector so that the UV light shines on it. If it fluoresces, it is a mushroom that has been soaked in fluorescent substances.
Dyed Oranges
Normal orange on the left
How to tell if an orange has been dyed
Oranges are a popular fruit, but when buying them, consumers must be very careful.
Identification Method:
1. Dyed oranges may look exceptionally bright red. Upon closer inspection, you may find red spots on the pores of the peel, and some may even have red residue on the surface.
2. Wipe the orange's surface with a wet tissue. If the tissue turns red, the orange may have been dyed. A non-dyed orange will only leave a faint yellow color on the tissue.
3. In severely dyed oranges, the navel (the stem end) will also turn red. In non-dyed oranges, the navel is a mix of white and green.
4. Dyed oranges feel sticky to the touch. Non-dyed oranges feel more natural.
Dyed Millet
Dyed moldy millet and undyed old millet
A simple method to identify dyed millet
In some farmers' markets, dyed millet has been found for sale. The "dyeing" process involves millet that has gone moldy and is inedible. Unscrupulous merchants wash it and then dye it with yellow dye to make it look brightly yellow and deceive buyers. Consuming this dyed yellow millet can harm the body.
1. Sensory Identification Method
Color: Fresh millet has a uniform, golden-yellow color with a lustrous sheen. Dyed millet has a deep yellow color, lacks luster, and the color of every grain looks identical.
Smell: Fresh millet has a normal millet aroma. Dyed millet may smell of the dye used, such as the turmeric-like smell of curcumin.
Washing: When fresh millet is rinsed with warm water, the water does not turn yellow. When dyed millet is rinsed with warm water, the water turns yellow.
2. Chemical Identification Method
Take a 25g sample and place it in a mortar. Add 25ml of absolute ethanol and grind. Take 25ml of the resulting suspension and place it in a colorimetric tube. Then add 2ml of 10% sodium hydroxide, shake well, let it stand for a moment, and observe the color change. If it turns orange-red, it indicates the millet has been dyed with curcumin.
Dyed Peanuts
Three ways to identify dyed peanuts
Because retail prices for red and purple peanuts are higher than for white peanuts, many vendors dye white peanuts with peach-red dye before roasting them for a small profit.
Identification Method: First, look at the appearance. Red-skinned peanuts have a small white spot at one end; if a peanut is entirely red, it may have been dyed. Second, the red skin of a peanut is very thin. If it has been dyed, you can see that the inner side of the skin is also light red. Additionally, take a single wet red peanut and rub it forcefully on a white piece of paper. If the peanut has been dyed, it will leave a red stain on the paper.
Dyed Black Sesame
Normal black sesame on the left
Be wary of black sesame that loses color easily
Normal black sesame will lose some color when soaked in water, but the color will not be too deep. The natural pigments in black sesame dissolve in water over a process, so raw black sesame soaked in cold water at room temperature will not lose color quickly, except for aged black sesame.
Identification Method: Place raw black sesame in cold water. If it loses color quickly, it is likely dyed. Also, since only the seed coat of black sesame is black and the endosperm is white, you can cut a black sesame seed open to see if the inside is white. You can also place black sesame seeds in your palm. If your palm quickly turns black, the black sesame is likely dyed.
Dyed Black Rice
Identifying real black rice by "one look, two smells"
When you buy black rice and it loses color, you should be警惕 (jǐng tì - vigilant) that you might have bought "dyed black rice."
Identification Method: You can judge the quality of black rice by "one look, two smells." "Look" means that with real black rice, only the outer bran is black, and the inner kernel is white. It will naturally shed some color during washing. Dyed black rice will have the entire grain black. "Smell" means that natural black rice has a natural rice aroma, while dyed black rice has an off-smell.