水分是易霉变饮片储存养护时霉变的关键影响因素，含水量难以预控饮片的霉变，以水分活度、含水量、分布均匀性与流动性为指标可准确表征饮片的水分特性，采用水分活度理论、低场核磁共振技术和核磁成像技术，研究水分特性对饮片霉变和品质的影响规律，建立水分吸附热力学参数，阐明饮片水分吸附与解吸附的机理和各相态水分的传质过程，确定饮片干燥终点的水分活度以及安全含水量。利用实时荧光定量PCR技术检测饮片上黄曲霉产毒关键合成基因、调控基因及生长基因在不同条件下表达水平，解析水分活度及温度对黄曲霉产毒关键基因表达量的影响。选择水分活度、温度等主要影响因素，模拟饮片储存环境，筛选减少霉变产毒的储存养护条件。本课题从宏观和微观上表征饮片中的水分特征，揭示水分对饮片霉变和其品质的影响规律及机理，为制定饮片的安全含水量和科学的储存养护条件提供理论和实验依据，因而具有很好的创新性和应用前景。

Moisture is the key influencing factor of mildew in the storage and maintenance of mildew-changing pieces. The mildew of the pieces is difficult to be pre-controlled by water content. Using water activity, water content, distribution uniformity and fluidity, the moisture characteristics of the pieces can be accurately characterized, and the moldy toxin production of the pieces can be effectively pre-controlled. Water activity theory, low field NMR and NMI techniques are used to study the effect of water characteristics on the mildew and quality of the mildew-changing pieces, and the thermodynamic parameters of water adsorption are established to clarify the mechanism of moisture adsorption and desorption of the pieces and the moisture of each phase. The mass transfer process is used to determine the Aw and safe water content of the dry end of the decoction piece. The real-time quantitative PCR is used to detect the expression level of key synthetic genes, regulatory genes and growth genes of Aspergillus flavus on the decoction pieces under different conditions, and the Aw and temperature on the influence of the expression level of key genes for the production of Aspergillus flavus are analyzed. The main influencing factors such as water activity and temperature are selected to simulate the storage environment of the pieces and screen the storage and maintenance conditions for reducing moldy toxin production. This topic from macroscopic and microscopic characterizes the moisture characteristics of the pieces, reveals the influence of moisture on the mold and its quality and its mechanism, selects the key factors and optimization conditions for the storage and maintenance of the pieces, and provides ideas and basis for the development of safe moisture content and scientific storage and maintenance conditions. Therefore, it has good innovation and application prospects.