[Application and prospect of "couplet medicine" techniques in preservation of Chinese medicinal materials]

Chinese medicinal materials (CMMs) are easily to be contaminated by all kinds of molds to produce various mycotoxins due to their internal factors and the external environmental conditions during the growth, harvesting, processing, and especially storage processes. This will not only affect the quality of CMMs, resulting in enormous financial loss, but also influence the safety and effectiveness of CMMs, posing potential threats to human health. With the increase in awareness of "traditional Chinese medicine health" idea, more and more attention has been paid on how to prevent and control these CMMs from being mouldy to guarantee their safety. Some physical and chemical techniques have been restricted for protecting CMMs due to their own disadvantages. As a green, safe and economic strategy for the preservation of CMMs, "couplet medicine" technique based on the principle of "protecting CMM with another CMM" has been developed: two kinds of CMMs are stored together and fight against each other to prevent mildew metamorphism, exhibiting no obvious changes in color, smell and quality. Nowadays, certain application results have been obtained for the "antagonistic storage" method based on the above mode and principle. In this paper, we would review and discuss the mechanism, practical application and the problems of "couplet medicine" technique, and provide scientific evidences for developing safe and effective tools to protect CMMs from being mouldy.