Watch out for high-value vegetables and fruits! Tg.jpg
Sodium pyrosulfite is often used to bleach and preserve vegetables and fruits. Graph/Vision
In recent years, vegetable and fruit "beauty art" has emerged in endlessly, not only products such as "auxin", "erythropoietin", "swelling" and preservatives, but also means of dyeing, waxing and bleaching, which make consumers fear.
A recent visit by a reporter from the Beijing News found that "beauty agents" for vegetables and fruits can be easily purchased through the Internet. Experts believe that the proliferation of fruit and vegetable "beauty art" is related to consumers'consumption habits of "taking fruit by appearance", and illegal use of chemical agents beyond the scope of national permission poses a huge food safety risk.
"Insurance powder" with low input and high output often gives bean sprouts "beauty"
Guangzhou police seized 450 kg of non-fresh food chemical additives such as "insurance powder". According to the authoritative inspection, the desquamated horseshoe and taro captured at the scene are seriously exceeding the standard of sulfur dioxide, while the price of "insurance powder" per kilogram is only 3-4 yuan.
After sorting out the judgment documents since 2013, the journalists of the Beijing News found that there were more than 40 cases related to the illegal addition of "insurance powder", involving 12 provinces such as Shaanxi, Henan and Shandong, with the maximum amount involved amounting to 1.4 million yuan.
From the point of view of usage, "insurance powder" is mainly used by illegal traders to make bean sprouts, curd bamboo, River powder, chestnut and other foods, among which it is most commonly used in the production process of bean sprouts. According to reports, its function is to make the bean sprouts brighter, rootless, unusually strong and not easy to rot, and the yield can be more than doubled.
Li Gang, a researcher at Beijing Food Industry Research Institute, said that the chemical name of "insurance powder" is "sodium dithionite", which is a commonly used bleaching agent in industry. If bleaching vegetables and fruits with raw materials that can not meet the requirements of food grade, there may be heavy metal residues, causing abdominal pain, vomiting and other health hazards.
The national standard shows that sodium pyrosulfite, sodium hyposulfite and other bleaching agents and preservatives are allowed to be added to preserved fruits and wines, but the dosage and usage should be strictly controlled. If the content of sulphur dioxide in food exceeds the standard seriously, it will constitute a criminal offence.
Insurance Powder can extend the shelf life of fruits and vegetables for 2-3 months
New Beijing News reporter found in the electronics business platform, many shops labeled sales of "insurance powder", "vegetables, fruit preservatives", "bean sprouts whitening agent" and other chemical products. The price of these "insurance powder" ranges from 2.5 yuan to 3.6 yuan per kilogram, and most businesses are unable to provide "food additive production license" and other information. According to the regulations, the production and sale of food additives need to provide relevant special licenses.
"Many fruit vendors come to buy insurance powder." One businessman said that it sells food-grade "insurance powder", which can extend the shelf life. Every kilogram of fruits and vegetables can be sprayed or soaked with 0.3-1 g of "insurance powder" diluted with water, and there is no need for second rinsing. After soaking, the appearance and taste of fruits and vegetables will not be affected. The store page information shows that its recent orders have reached more than 350.
In the buyer's evaluation, some customers said that "insurance powder" bleached bean sprouts had no effect. Shop responded that sodium pyrosulfite could not be used alone in food bleaching, citric acid or dilute hydrochloric acid must be added, but used alone as preservatives, antioxidants or color protectors, although there are relevant dosage regulations.
The reporter consulted another shop as a fruit and vegetable shop owner and learned that "preservative" can extend the shelf life of fruits and vegetables to 2-3 months, and add 3 grams of products to 1 jin of water. Shopkeepers revealed that many customers use "insurance powder" to soak food, in addition to peeling taro, lotus root slices, but also used in yam, shellfish and other food.
In market visits, Beijing News reporters found that compared with apples, oranges and other waxing conditions, ordinary consumers are often more difficult to determine whether the selected fruit has been treated with preservatives, bleaching agents and so on. "Many fruits with additives are difficult to find significant differences in appearance and taste." A 20-year fruit business insider told the Beijing News.
Common Vegetables and Fruits "Beauty Art"
1 Bleaching
Case: In 2015, Handan Public Security Bureau seized more than 100 cases of Tremella fumigated with sulfur. Smoked Tremella fumigatus has a white appearance and is quite attractive, but it has a distinct smell of sulfur dioxide. The results showed that the sulfur dioxide content in Tremella fuciformis exceeded the standard by at least 10 times.
Analysis: Fan Zhihong, associate professor of Food College of China Agricultural University, pointed out that bleaching yellow cauliflower, tremella, dried pepper and dried apricot with food grade sulfur is legal, but the residue can not exceed the standard. Industrial sulfur yellow is especially harmful to human body because it contains more heavy metals.
In addition to powder and sulphur, the common bleaching agents are sulphur dioxide, chlorine dioxide, hydrogen peroxide and so on. Ren Hao, a professor at the School of Chemistry and Chemical Engineering of Jinan University, said that according to the current national standards, hydrogen peroxide should not be detected in the final products. According to relevant literature data, 3% of hydrogen peroxide does not produce serious toxicity either orally or in skin contact, but 10% to 30% of hydrogen peroxide can cause mild burning of the mouth, trachea, stomach and skin.