油橄榄果渣膳食纤维碱法提取工艺优化及其理化性质研究

摘要

Using olive pomace as the raw material, the alkali method was adopted to extract soluble dietary fiber (SDF) and insoluble dietary fiber (IDF), and its physicochemical properties were also studied.The extraction conditions of IDF and SDF were optimized through orthogonal test based on single factor test.The results showed that the optimum extraction conditions were concentration of NaOH 8%, the extraction temperature of 80 ℃, the extraction time 80 min, and liquid-solid ratio of 15∶1(mL∶g).Under this conditions, the yields of SDF and IDF were 28.74% and 52.39%, respectively.The results of physicochemical properties showed that the water holding capacity,swelling capacity and oil holding capacity of IDF were 3.38 g/g, 2.20 mL/g, 1.91 g/g, respectively.The water holding capacity, swelling capacity and oil holding capacity of SDF were 5.05g/g, 4.78 mL/g and 4.25 g/g, respectively.The glucose dialysis retardation index of SDF, IDF and defatted pomace were 13.22%,8.55% and 4.38%, respectively, by the dialysis for 90 min.The results of scanning electron microscope showed that IDF had looser morphology and more cavities and cracks, and SDF had smaller particle size and more cavities after alkali extraction.%以油橄榄脱脂果渣为原料,采用碱法提取油橄榄果渣水溶性膳食纤维(SDF)和水不溶性膳食纤维(IDF),并对其理化性质进行研究.在单因素试验基础上采用正交试验优化油橄榄果渣膳食纤维最佳提取工艺条件为: NaOH质量分数8%、提取温度80 ℃、提取时间80 min、液料比15∶1(mL∶g).在最佳提取工艺条件下,油橄榄果渣SDF产率为28.74%,IDF产率为52.39%.理化性质研究结果表明:油橄榄果渣IDF的持水力、膨胀力和持油力分别为3.38 g/g、 2.20 mL/g、 1.91 g/g;油橄榄果渣SDF的持水力、膨胀力和持油力分别为5.05 g/g、 4.78 mL/g、 4.25 g/g.在透析90 min时,油橄榄果渣SDF、IDF和脱脂果渣的葡萄糖透析延迟指数分别为13.22%、 8.55%、4.38%.扫描电镜观察表明,制备的IDF结构疏松,具有较大的空腔和裂缝,而SDF粒径较小,呈堆积状,具有较多的空腔.