Hello everyone! I am Dad Fu, a practicing physician who has focused on weight management and nutritional treatment of diseases for more than 20 years. Hope my article is useful to you.

Pu'er tea is a unique local tea species in China. According to my country's national standard "Geographical Indication Product Pu'er Tea" (GB/T 22111-2008), Pu'er tea is a product of Yunnan Province within the scope of geographical indication protection. Large-leaf sun-dried green tea is used as raw material and is made using specific processing techniques within the scope of geographical indication protection. Pu'er tea is a fermented tea, which is divided into two types: raw tea and cooked tea according to the degree of fermentation. Pu'er tea has a mellow taste and many people like to drink it.

However, there have been some rumors on the Internet in the past two years that Pu'er tea is prone to mold growth during the fermentation process and will produce aflatoxin, and the older Pu'er tea has more aflatoxin. Aflatoxin is a well-known carcinogen, and it is no joke that Pu'er tea contains aflatoxin. So, does Pu'er tea really contain aflatoxin?

Pu'er tea is fermented tea. The so-called fermented tea is to allow certain types of bacteria and mold to grow and multiply in the tea leaves. This is true for black tea and oolong tea. We need to be clear that not all bacteria and molds are toxic and harmful, and some bacteria and molds are also beneficial to human health. For example, Bifidobacterium and Lactobacillus bulgaricus are used to make yogurt, lactic acid bacteria are used to make sauerkraut, and Monascus is used to make red yeast rice. They are all microorganisms that are beneficial to the human body. It’s just that different regional climates and fermentation environments are suitable for the growth of different strains of bacteria, and even different strains of bacteria grow during different fermentation periods.

The climate and fermentation process of the origin of Pu'er tea determine the fermentation strains of Pu'er tea. In the early stage of fermentation, Aspergillus niger and Rhizopus are the main microorganisms in the tea. In the later stage, Aspergillus griseus, Penicillium and yeast appear. These molds are harmless to human health and are also responsible for the special flavor of Pu'er tea.

So during the fermentation process of Pu'er tea, will aflatoxin contamination occur? Aflatoxins are produced by strains of Aspergillus aflatoxin and Aspergillus parasiticus. The growth of these molds also requires a suitable environment. For example, improperly stored grains such as corn and peanuts that are affected by moisture are particularly susceptible to aflatoxin contamination. However, the fermentation process of Pu'er tea is not suitable for the growth and reproduction of Aspergillus flavus and Aspergillus parasiticus, and the longer the fermentation time of Pu'er tea is, the less suitable it is for the growth of Aspergillus flavus and Aspergillus parasiticus. Therefore, as long as the Pu'er tea has passed the fermentation process, it will not be contaminated by aflatoxin.

Of course, this is just a theoretical analysis. Let’s see how it actually plays out. In order to understand whether there is aflatoxin in Pu'er tea, an authoritative test was conducted in 2018. The test covered 8 types of Pu'er tea with relatively large sales in the market. In order to reduce the interference of production year factors, Pu'er tea of ??different years was also specially selected, with storage times ranging from a few months to four years. The conclusion is: No aflatoxin was detected in these 8 Pu'er teas!

Of course, there is a prerequisite here, that is, the Pu'er tea is produced in a qualified manner and must be properly stored before drinking. If Pu'er tea is not stored properly and becomes damp, it may be contaminated by bacteria. Pu'er tea does taste better as it ages, but it must be stored well. Therefore, to drink Pu'er tea, you must first learn how to preserve Pu'er tea. If you do not have the preservation conditions or do not know how to preserve it, it is recommended to buy a small amount at a time and drink it before buying. Of course, we have to buy regular brand Pu'er tea sold through regular channels.