Response Surface Optimization of The Fermentation Process of Mulberry Leaf Tea by Eurotium Cristatum

School of Bioengineering, Shandong Provincial Key Laboratory of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China

^* Corresponding author: zhuliping2012@aliyun.com

Abstract

1-Deoxynojirimycin (DNJ), a functional ingredient in mulberry leaf tea, was used as an indicator during the response surface optimization of the solid-state fermentation process to prepare mulberry leaf tea with Eurotium cristatum in order to improve the quality of the product. The product α-glucosidase inhibitory activity was then examined. The findings indicate that the optimal conditions for preparing mulberry leaf tea fermented by E. cristatum are a 40% moisture content in the substrate, a 5% inoculum amount for 6 days of fermentation, and a maximum DNJ content of 3.09 mg/g. The resulting products had a golden yellow color, a reddish-brown tea broth, a full-bodied taste, and no longer had any grassy flavor. These results effectively improved the quality of the mulberry leaf tea and offered a theoretical foundation for the production of high-quality mulberry leaf tea.