红薯渣不溶性膳食纤维超高压改性

Modification of insoluble dietary fiber from sweet potato residue with ultra high pressure processing technology

为增强红薯渣膳食纤维的生理功能,研究超高压对其理化性质的影响。该文以红薯渣为原料,采用均匀试验方法对不溶性膳食纤维产品理化性质进行超高压改性,并通过扫描电镜、毛细管电泳法、红外光谱、X射线衍射、比表面积测试法BET和粒度等手段研究改性对膳食纤维结构及理化性质的影响。结果表明:超高压改性不溶性膳食纤维的工艺条件如压力、时间、温度对其调节血糖、血脂、清除外源有害物质能力有显著影响。得出超高压对调节血糖、血脂能力改性条件:600MPa,15min,60℃;清除外源有害物质改性条件:100MPa,10min,42℃。通过对改性膳食纤维结构、理化性质测定发现,改性红薯渣不溶性膳食纤维的微观结构为疏松、光滑、蜂巢形的多孔网状结构;其单糖组分没有太大影响,单糖含量产生了一定程度的变化;改性使结晶度减小,比表面积增大;特征吸收峰增强、红移和蓝移,同时也产生了一些新的吸收峰。研究结果可为红薯渣膳食纤维的功能改性及综合利用提供相关依据。

In order to improve the physiological functions of dietary fiber from sweet potato residue, insoluble dietary fiber （IDF） was prepared from sweet potato residue for physical and chemical properties ultra-high pressure modification with uniform test method. And insoluble dietary fiber was characterised by the methods of SEM, HPCE, FT-IR, XRD, BET and particle size. The conclusion shows that the pressure （X1）, processing time （X2） and temperature （X3） had the significant influences on glucose regulation, blood fat regulation and the ability of removing exogenous harmful substances in modified IDF. The optimum processing conditions were that the glucose regulation and blood fat regulation capacity were pressure of 600 MPa, processing time of 15 min and temperature of 60℃; The ability of removing exogenous harmful substances were pressure of 100 MPa, processing time of 10 min and temperature of 42℃. The physicochemical property shows that the microstructure of sweet potato residue IDF modified by the ultra-high pressure was loose, smooth, porous with honeycomb-shaped and massive structure. Either modification didn’t affect the monosaccharide compositions, but the contents of monosaccharide changed a little. Meanwhile, crystal and particle size of modified IDF reduced, the specific surface area increased. The characteristic absorption peaks enhanced and a red shift or blue shift appeared, and a number of new absorption peaks occured. The research can provide a reference for functional modifications and utilization of dietary fiber from sweet potato residue.