正交试验优化菠萝果渣膳食纤维制备及其性质的比较

Preparation and Properties of Dietary Fiber from Pineapple Pomace

以菠萝果渣为原料,分别采用酸法和碱法制备水溶性和不溶性膳食纤维,初步分析比较两种方法制备的水不溶性膳食纤维的理化性质。结果表明:酸法制备水溶性膳食纤维的最佳条件为温度90℃、pH1.0、时间90min、料液比1:10,其得率为8.1%(以干渣计),水不溶性膳食纤维提取条件为温度60℃、pH2.0、时间60min,得率为24.4%(以干渣计),水不溶性膳食纤维的膨胀力高达9.25mL/g,持水力为5.85g/g,持油力为1.35g/g、阳离子交换能力为0.21mmol/g;碱法制备的水不溶性膳食纤维最佳提取条件为碱液质量分数1%、料液比1:15、时间40min、温度50℃,其得率为62.80%,持水力为3.82g/g、膨胀力为10.66mL/g、持油力为1.75g/g、阳离子交换能力为0.27mmol/g。故碱法制备的水不溶性膳食纤维得率更高,性质相对较好。

The soluble and insoluble dietary fibers were prepared with acid hydrolysis and alkali hydrolysis from pineapple pomace and their properties were also compared. The extraction process was optimized by orthogonal tests. The results showed that the optimal extraction conditions for insoluble dietary fiber required reaction temperature of 60 ℃, reaction time of 60 min and hydrolysis pH of 2.0 during acid hydrolysis; NaOH concentration of 1%, material-liquid ratio of 1 ： 15, reaction temperature of 50 ℃ and reaction time of 40 min during alkali hydrolysis. The optimal extraction condition for soluble dietary fiber required reaction temperature of 90 ℃, hydrolysis pH of 1.0, hydrolysis duration of 90 min and material-liquid ratio of 1：10 during acid hydrolysis. The maximum yield of soluble and insoluble dietary fiber by acid hydrolysis could reach 8.1% and 24.4%, respectively, and the maximum yield of insoluble dietary fiber by alkali hydrolysis was 62.80%. The water- holding capacity, swelling capacity, oil-holding capacity and cation exchange capacity （CEC） of water insoluble dietary fiber from both hydrolysis methods were 5.85 g/g and 3.82 g/g, 9.25 mL/g and 10.66 mL/g, 1.35 g/g and 1.75 g/g, and 0.21 mmol/g and 0.27 mmol/g, respectively. Therefore, higher maximum yield and better properties of dietary fibers were achieved during alkali hydrolysis.