物理法改性对不同品种柑橘皮渣纤维结构及理化功能特性的影响

Effects of physical modification on structural and physico-chemical functional properties of fibres from different varieties of citrus peel pomace

针对柑橘皮渣综合利用率低的现状,该实验以3种柑橘皮渣(柠檬、沃柑、脐橙)为原料,采用高速剪切、超声波、高温高压3种方式对其进行物理改性,探究不同改性方式对不同柑橘皮渣纤维结构和理化功能性质的影响。结果表明,3种改性均使柑橘皮渣纤维粒径减小,比表面积增大,相对结晶度降低,热稳定性提高,而主要官能团未发生明显改变;其中高速剪切改性效果优于其他2种改性方式,经高速剪切后柑橘皮渣纤维的可溶性膳食纤维含量、持水力、持油力、膨胀力、总黄酮和总酚含量、吸附胆固醇和亚硝酸盐能力提升效果最为显著(P<0.05);3种柑橘品种中柠檬皮渣纤维表现最好。综上,高速剪切是改性柑橘皮渣纤维最好的方式;经高速剪切后的柠檬皮渣纤维结构和理化功能特性均优于沃柑和脐橙,更利于其在食品中的应用,该结果可为扩大柑橘加工副产物的综合利用提供参考。

Aiming at the current situation of low comprehensive utilization of citrus peel pomace,three varieties of citrus peel pomace(lemon,orah,and navel orange)were taken as raw materials,and three physical modification techniques,including high-speed shear,ultrasonic,and high temperature-high pressure,were utilized to modify the citrus peel pomace.The effect of each modification on the fibre structural and physicochemical functional properties of the different citrus peel pomace samples was investigated.Results showed that the three modifications reduced the particle size of citrus pomace fibres,increased the specific surface area,decreased the relative crystallinity,and improved the thermal stability,while the main functional structures were not significantly altered.Among them,the effect of high-speed shear modification was better than that of the other two modifications,and the soluble dietary fiber(SDF)content,water-holding capacity,oil-holding capacity,swelling capacity,total flavonoids and phenols content,and adsorption of cholesterol and nitrite capacity of citrus peel pomace fibers after high-speed shear had the most significant enhancement effects(P<0.05).Lemon peel pomace fiber had the best performance among the three citrus varieties.In conclusion,high-speed shear was the best way to modify citrus pomace fiber.The structural and physicochemical functional properties of lemon peel pomace modified by high-speed shear were better than those of orah and navel orange,which were more conducive to their application in food products,and the results could provide some references for expanding the utilisation of citrus processing by-products.