真空冷冻干燥与热风烘干对香蕉皮可溶性膳食纤维功能特性的影响

The Effects of Vacuum Freeze Drying and Hot Air Drying on the Functional Characteristics of Soluble Dietary Fiber from Banana Peel

以香蕉皮为原料,经过烘干、提取、浓缩后分别采用真空冷冻干燥和热风烘干制得可溶性膳食纤维,比较两种干燥方式对香蕉皮可溶性膳食纤维持油力、阳离子交换量、胆固醇吸附特性的影响,进一步探究其在模拟胃、肠条件下对亚硝酸根、铅、镉的吸附效果.结果表明,真空冷冻干燥样品的持油力和对胆固醇、NO_2^-、重金属Pb^(2+)、Cd^(2+)的去除效果均好于热风烘干;添加量为5g/L时胆固醇具有最大吸附效率;可溶性膳食纤维对NO_2^-的吸附主要集中在胃部;真空冷冻干燥样品的阳离子交换量略小于热风烘干.干燥方式对可溶性膳食纤维分子的空间结构产生影响,进而影响了可溶性膳食纤维的功能特性.

The soluble dietary fiber was extracted,concentrated,and then dried by vacuum freeze or hot air from banana peel.The differences of oil holding capacity,cationic exchange capacity,cholesterol absorptivity of soluble dietary fiber dried by vacuum freezing and hot air were compared.Furthermore,their absorptivity of NO2^-,Pb^2＋,Cd^2＋ in imitative gastroenteric environments was studied.These results showed that oil holding capacity,absorptivity of cholesterol,nitrite,Pb^2＋,Cd^2＋ of the peel dried by vacuum freeze were higher than that by hot air.The soluble dietary fiber achieved maximum adsorption efficiency at the dose of 5g/L.The NO2^-absorption of soluble dietary fiber was occurred mainly in the gastric environment.The cationic exchange capacity of vacuum freeze dried sample was slightly less than that of by hot air drying.These results indicated that the drying methods make impact on molecular space structure of soluble dietary fiber,leading to the functional characteristics difference of the soluble dietary fiber.