Recently, a news of "boiled peanuts and edamame on barbecue stalls add formaldehyde for antiseptics" spread on the Internet, which can make many Chengdu people who love cold cups worry. So, do the boiled peanuts and edamame sold in Chengdu restaurants and street stalls also add formaldehyde? In order to verify this news, on the evening of the 23rd, the Chengdu Business Daily reporter randomly purchased 6 copies of boiled peanuts and boiled edamame from four catering gatherings, namely Kehua North Road, Mengchaiwan Wangping Street, Yulin Jixiang Street and Huaxingzheng Street, and placed them in the refrigerator that night. The next day, the reporter sent 12 samples to the Institute of Agricultural Product Processing of Sichuan University, and the testers conducted a rapid test on whether the samples contained formaldehyde.
No problem
None of the 12 samples contained formaldehyde
On the 24th, the reporter sent the 12 samples purchased to the Food Science and Engineering Professional Food Analysis Laboratory of the Institute of Agricultural Product Processing of Sichuan University, and the testers conducted a rapid test on whether the samples contained formaldehyde in accordance with the DB44/T519-2008 (rapid detection method of formaldehyde in food).
The inspector Ma Lin first divided the 12 samples into a peanut group and a edamame group. She then cut the sample into pieces with a knife and numbered the sample fragments into 12 Miller flasks, adding an appropriate amount of distilled water, and Ma Lin began to shake the Miller flasks one by one. "The sample is sniptured to increase the contact area between the sample and the water, and the oscillation and 'water bath' are to speed up the dissolution of formaldehyde."
At the same time as the water bath, Ma Lin prepared a very important reagent in this detection experiment - 1% resorcinol solution. "The principle of this experiment is that under strong alkaline conditions, formaldehyde will have a color reaction with resorcinol to form an orange-red complex." Ma Lin told reporters.
After ten minutes, 12 grinding-mouth Erlenmeyer flasks are removed from the water bath pot and the sample immersion solution is ready. "It's time to start testing." Ma Lin said. She first added 0.2 mL of 1% resorcinol solution to the 1.5 mL stopper centrifuge tube, then added 1.0 mL of sample soaking solution of Edamame Group 1 to the tube, and then squeezed the upper and lower ends of the centrifuge tube with her hands and shook well. Subsequently, she took out a new centrifuge tube with a plug and added only the 1.0 mL sample soak solution of Edamame Group 1, "This is the blank group, compare it with the experimental group." ”
Ten minutes later, Ma Lin placed the experimental group and the blank group centrifuge tube of the edamame group No. 1 on the white paper, "We can see that the experimental group of all the samples is not discolored, and this sample does not contain formaldehyde." ”
According to this observation method, the reporter saw that the color of the experimental group sample was slightly darker than the blank group. In this regard, Ma Lin explained: "This is due to the pigment dissolved in the organic solvent, as long as the color of the solution does not change orange red or light red, it means that the sample does not contain formaldehyde." In the end, Ma Lin came up with the test results of the experiment - none of the 12 samples contained formaldehyde.
Inspectors test peanut edamame samples during the process
As a matter of fact
"If it is produced in small quantities
Adding formaldehyde increases costs."
For the experimental results of formaldehyde that were not detected in the 12 samples, Xie Wangjun, a researcher at the Institute of Agricultural Product Processing of Sichuan University, explained: "Formaldehyde does have antiseptic effects, but the production cost of edamame and peanuts itself is not high, if it is a small amount of production and sale by merchants, adding formaldehyde will increase the cost." ”
In the process of visiting and buying, 9 merchants such as Yulin Skewer Incense, He Shi BBQ, Zi tong Qiao Wang Mei Skewer Incense, and Wangping Street Vendors all said that peanuts and edamame were made by them on the same day, and they could basically sell out every day. "If you can't sell it, you can eat it yourself, or just pour it." Zi tong bridge Wang Mei string incense staff said.
Of course
About formaldehyde,
We need to know:
● What is formaldehyde
Formaldehyde (HCHO) is a colorless, strongly irritating gas, easily soluble in water and methanol, with antiseptic, bactericidal and bleaching functions. At present, formaldehyde has been identified as a Class 1 carcinogen by the International Agency for Research on Cancer under the World Health Organization, and the Food Sanitation Law of the People's Republic of China clearly stipulates that formaldehyde and formaldehyde-containing compounds are prohibited from being used as food additives.
● The harm of formaldehyde
Xie Wangjun, a researcher at the Institute of Agricultural Product Processing of Sichuan University, told reporters that formaldehyde oral poisoning can directly damage people's mouth, throat, esophagus and gastric mucosa, while causing the human body to produce different degrees of poisoning reactions, light is manifested as cough, dizziness, vomiting, epigastric pain, and heavy cases will appear liver and kidney dysfunction, pulmonary edema, coma, shock, and even death.
Chengdu Business Daily intern reporter Yin Qintong Photojournalist Zhang Shibo Editor Autumn