Optimization of Ultrasonic-assisted Composite Enzyme Extraction Process for Soluble Dietary Fiber in Chestnut Kernels and Its Structural Characterization
Taking Yanshan chestnut as the raw material,an ultrasonic-assisted composite enzyme method was employed to extract dietary fiber from chestnut.A single-factor experiment was conducted to study the effects of compound enzyme(m(α-amylase)∶m(saccharifying enzyme)=4∶1)addition,neutral protease addition,and ultrasonic treatment time on the extraction rate of dietary fiber from chestnut.A response test was designed to optimize the influencing factors in the enzymatic hydrolysis process.The structure was characterized by scanning electron microscopy,infrared spectroscopy and thermogravimetric analysis.The results showed that the optimal conditions for extracting dietary fiber with the measurement of chestnut quality and the ultrasound-assisted composite enzyme method were 11％of the composite enzyme addition,4％of the neutral protease addition,and 15 min of the ultrasound time,under which the extraction rate of dietary fiber from chestnuts was 22.22％.The scanning electron microscope showed that the dietary fiber of chestnut presented a loose sheet-like or layered structure with many pores on the surface.The infrared spectrum showed that it featured absorption peaks of dietary fiber.Thermogravimetric analysis showed that chestnut dietary fiber was suitable for processing at temperatures below 400 ℃.The ultrasound-assisted composite enzyme method could effectively extract dietary fiber from chestnuts.
万方数据
维普
