摘要
采用表面糊化技术揭示小麦淀粉乙酰化、羟丙基化及复合改性处理过程中取代基团在颗粒内的分布及分子质量变化过程。通过扫描电子显微镜、凝胶排阻色谱研究淀粉的颗粒特性、分子质量及取代基团分布的变化。结果表明:随着表面糊化程度的提高,小麦淀粉表面变得粗糙,有明显的剥蚀现象,剩余淀粉保持颗粒状态;表面糊化处理后小麦淀粉总糖含量、蓝值均明显降低,剩余淀粉颗粒直链淀粉质量分数呈下降趋势;小麦淀粉经过乙酰化、羟丙基化以及乙酰化羟丙基复合改性后,随着表面糊化处理时间的延长,剩余淀粉颗粒的取代度呈下降趋势。表面糊化处理后外层糊化的程度越高,所获得的剩余淀粉颗粒取代度越低,这表明乙酰化、羟丙基化的取代反应主要在淀粉颗粒的外层发生,颗粒内部的取代程度较低。无论单一或复合改性淀粉,取代基团都主要分布在颗粒的表层。
Chemical surface gelatinization (CSG) technique was employed to unravel uncover the location of acylation and hydroxypropylation groups in wheat starch granules and the change of molecular mass of wheat starch. Granule properties, molecular mass and substitution group distribution were determined using scanning electron microscopy and gel permeation chromatography. The results indicated that: as theincrease in degree of surface gelatinization increased, the particle surface became rough and showed obvious peeling;the remaining part was still in the granular state. The total carbohydrate content and blue value were decreased after CSG and the remaining granules showed a decreased amylose content. The substitution degree of the remaining granules of mono and dual modified starches decreased with increasing duration of CSG treatment. The higher the gelatinization degree of the outer layer, the lower the degree of substitution of the remaining granules indicating that acetylation and hydroxypropylation modifications occur mainly in the outer part of the granule and the substitution groups primarily exist on the surface of both modified starch granules.
作者
赵凯
刘宁
李君
雷鸣
陈威
杨春华
陈凤莲
ZHAO Kai;LIU Ning;LI Jun;LEI Ming;CHEN Wei;YANG Chunhua;CHEN Fenglian(Local Key Laboratory of Food Science and Engineering,Harbin University of Commerce,Harbin 150076,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2020年第7期66-72,共7页
Food Science
基金
哈尔滨市科技创新人才项目(2014RFXXJ068)
哈尔滨商业大学校内科研项目(18XN075)。
关键词
小麦淀粉
表面糊化
取代基团
复合改性
分子质量分布
wheat starch
surface gelatinization
substitution groups
dual-modification
molecular mass distribution
