Recently, the topic of aflatoxin growing on frozen steamed buns after being kept for more than two days has sparked public concern. Is it safe to consume frozen steamed buns? How should steamed buns be stored scientifically? And how can we prevent the risk of aflatoxin exposure in daily life? Reporters have sought verification on these issues.
"Frozen steamed buns do not produce aflatoxin under normal conditions, as aflatoxin is mainly produced by molds such as Aspergillus flavus in high-temperature, high-humidity environments. The frozen environment (around -18°C) is not conducive to mold growth," said Wu Jia, Deputy Secretary-General of the Nutrition Literacy Branch of the Chinese Health Promotion and Education Association. If the steamed buns have already been contaminated by mold before freezing, the mold toxins will not be eliminated even if they are frozen. Therefore, frozen steamed buns that are fresh and unmolded before freezing can be consumed with confidence. If the steamed buns have an unusual odor, color change, or abnormal surface after thawing, they should be discarded to avoid consumption.
According to "Nutrition and Food Hygiene," aflatoxin is a metabolite produced by Aspergillus flavus and Aspergillus parasiticus, which are common fungi in grain and feed. In China, Aspergillus parasiticus is relatively rare. The temperature range for Aspergillus flavus to grow and produce aflatoxin is 12°C to 42°C, with the optimal temperature for aflatoxin production being 25°C to 33°C, and the optimal water activity value being 0.93 to 0.98.
Aflatoxin is mainly produced by molds in warm and humid environments. Taking precautions in daily life can effectively reduce the risk of exposure and ingestion of aflatoxin. Experts recommend choosing reputable brands and sellers when purchasing food to ensure freshness and safety. When storing food, attention should be paid to the shelf life, and food should be stored in a dry, well-ventilated, and dark environment to reduce the opportunity for mold growth. It is particularly important to note that storing food in the refrigerator is not a foolproof method, as foods have optimal storage times. During food processing and cooking, foods should be thoroughly washed, and attention should be paid to cooking methods.
Furthermore, due to the good thermal stability of aflatoxin, it is not easily decomposed by conventional cooking and heating. Moldy food should be avoided, and even if the moldy part is removed, the rest should not be consumed. Additionally, food safety awareness should be enhanced, and kitchen utensils such as chopsticks and cutting boards should be cleaned promptly and replaced regularly to prevent the growth of mold and bacteria.
Regarding the scientific storage of steamed buns, Wu Jia stated that frozen storage is relatively the safest and best-tasting option. However, it should be noted that steamed buns should be sealed in food bags or plastic wrap to avoid contact with air, prevent water evaporation, and avoid contamination from odors. Steamed buns that are not contaminated by mold can be consumed within six months if stored in a frozen environment below -18°C. In a refrigerated environment, they can be kept for one to two days but also need to be sealed to avoid moisture.
Post time: Dec-19-2024