摘要
研究了超声处理1.5和2.5 h和半乳糖苷酶酶解16、32和48 h对罗望子木葡聚糖(Xyloglucan,XG)流变特性的影响。使用旋转流变仪对处理前后的木葡聚糖在静态剪切和动态剪切下的黏度和模量进行了分析,并利用凝胶色谱-多角度激光光散射和动态激光光散射仪对木葡聚糖分子量分布和平均粒径进行了分析,同时使用扫描电子显微镜对木葡聚糖的微观结构进行了观察。温度扫描结果表明,在5℃时,超声和酶解处理过的木葡聚糖的黏度显著降低(P<0.05),但不同处理时间的样品差异较小。在5~60℃范围内,木葡聚糖的弹性模量与黏性模量均接近于7 Pa。超声处理的样品黏度随温度增加而降低,且总体呈现出以黏性为主的流变特性。48 h酶解处理的木葡聚糖弹性特征高于16及32 h酶解木葡聚糖的弹性特性。分子量分析结果显示,超声处理1.5和2.5 h的木葡聚糖平均分子量从原885 kDa分别降低至780和520 kDa;而酶解的木葡聚糖由低分子量(101~478 kDa)和高分子量(4591~12173 kDa)两部分组成,其中低分子量组分比例占80%以上。动态光散射结果表明,经半乳糖苷酶酶解的木葡聚糖平均粒径增大,而超声对样品的粒径影响较小。本研究为物理及生物法改性木葡聚糖,以获得具有不同流变特性的多糖胶体提供了一定经验,有利于进一步拓展其在食品工业中的应用。
The effects of 1.5 and 2.5 h of ultrasonic treatment and 16,32 and 48 h of enzymatic hydrolysis with galactosidase on the rheological properties of Xyloglucan(XG)from tamarind were studied.The viscosity and module of untreated and treated XG were studied under static and dynamic shear using a rotational rheometer.The molecular weight distribution and average particle size were analyzed using gel chromatography with multi-angle laser light scattering and dynamic laser light scattering instruments.In addition,the microstructure of XG samples were observed via scanning electron microscope.Results of the temperature sweep showed that the viscosity of XG treated by ultrasound and enzymatic hydrolysis significantly decreased at 5℃,but the difference of samples treated for different durations was small.In the range of 5 to 60℃,the elastic and viscous modulus of XG were close to 7 Pa.The viscosity of ultrasonic treated XG decreased with the increasing of temperature,and the rheological properties of ultrasonic samples was viscous-dominant.The elastic properties of XG treated with 48 h enzymatic hydrolysis were higher than those treated with 16 and 32 h enzymatic hydrolysis.The results of molecular weight analysis showed that the average molecular weight of ultrasonic-treated 1.5 and 2.5 h XG decreased from 885 kDa to 780 and 520 kDa respectively.The enzymatic hydrolysis of XG was composed of a low molecular weight(101~478 kDa)ratio and a high molecular weight(4591~12173 kDa)ratio,of which the low molecular weight component accounted for more than 80%.The results of dynamic light scattering showed that the average particle size of XG increased after galactosidase hydrolysis,while ultrasonic treatment had little effect on the particle size of XG.This study would provide experience on the physical and biological modification on xyloglucan to obtain carbohydrate colloids with various rheological properties,which is beneficial for its further application in food industry.
作者
廖秋冬
曹潇
陈思谦
王凯
LIAO Qiudong;CAO Xiao;CHEN Siqian;WANG Kai(College of Food Science,South China Agricultural University,Guangzhou 510642,China;School of Chemical Engineering and Energy Technology,Dongguan University of Technology,Institute of Sincence&Technolgy Innovation,Key Laboratory of Healthy Food Development and Nutrition Regulation of China National Light Industry,Dongguan 523808,China)
出处
《食品工业科技》
CAS
北大核心
2023年第4期114-121,共8页
Science and Technology of Food Industry
基金
国家自然科学基金资助项目(31801544)。
