采用化学法从脱脂核桃粕中提取膳食纤维,研究5种不同粒度条件下(＜40、40～60、60～80、80～120、120～160、＞160目)核桃粕膳食纤维在持水力、膨胀性、吸油性、粘度、阳离子吸附力、葡萄糖阻滞力等理化性质方面的差异,以期为核桃粕膳食纤维的综合利用提供理论依据.结果显示,化学法提取的核桃粕膳食纤维得率为12.47％,膳食纤维含量为76.34％,蛋白质含量为5.41％;红外光谱扫描结果显示,核桃粕膳食纤维在3420 cm-1处具有明显的纤维素特征吸收峰,表明核桃粕膳食纤维结构基本未受到破坏.不同粒度范围的核桃粕膳食纤维持水力、膨胀性和粘度均有显著差异.其中,粒度在120～160目之间时,核桃粕膳食纤维持水力最好,为7.76 g·g-1;粒度在80～120目之间时,核桃粕膳食纤维膨胀值和粘度最大,分别为5.28 mL·g-1、21.25 mPa·s.核桃粕膳食纤维持油力(OAC值)随粒度减小呈增加趋势,当粒度＞160目时核桃粕膳食纤维OAC值达到1.92 g·g-1.此外,当核桃粕膳食纤维粒度为120～160目时,葡萄糖阻滞力最强,粒度为80～120目时,阳离子吸附能力最强.综合而言,核桃粕膳食纤维粒度在80～160目之间时,具备最佳的理化特性.%To provide basis and reference for the utilization of walnut dietary fibers,walnut dietary fibers were extracted using chemical extraction methods and the physiochemical properties of five fibers with different particles sizes,including below 40 mesh,40～60 mesh,60～80 mesh,80～120 mesh,120～160 mesh and beyond 160 mesh,were also investigated.Results suggested that the yield of walnut dietary fibers,composing mainly of 76.34 ％ of dietary fibers and 5.41％ of protein,was 12.47 ％.Infrared spectroscopy scanning pictures indicated that walnut dietary fibers had remark absorbance at 3420 cm-1,suggesting fiber structure had not been destructed.The significant differences of water-keeping capability,swelling capability and viscosity were observed during determining physiochemical properties of five dietary fibers with varying particle sizes.The best water-keeping capability,7.76 g· g-1,was observed in walnut dietary fibers with 120～ 160 mesh,and the best swelling capability and viscosity,5.28 mL·g-1,21.25 mPa· s,respectively,both were observed in dietary fibers with 80～120 mesh.However,walnut dietary fibers size over 160 mesh had the best oil-keeping capability,with 1.92 g·g 1.In addition,absorption capability of glucose was optimum at the particles 120 to 160 mesh,cation absorptin capability peaked at the particle range of 80 to 120 mesh.Overall,walnut dietary fibers with the particle size of 80～160 mesh had the optimun physiochemical properties.
展开▼
