摘要
以小麦淀粉和紫薯淀粉为材料,利用质构仪、核磁共振、动态流变仪和扫描电镜等分析了紫薯淀粉添加量(0~15%)对小麦淀粉凝胶特性的影响。结果表明:紫薯淀粉添加量在0~15%范围内,随着紫薯淀粉添加量的增加,小麦淀粉凝胶的弹性和内聚性显著增加(P<0.05),添加量为10%时,变化最明显。混合淀粉凝胶的弹性模量(G′)和粘性模量(G″)随着紫薯淀粉增加而增加,而损耗角正切值(tanδ)呈下降趋势且小于1,表明混合淀粉凝胶的固体性质增强。在冻融循环过程中,与纯小麦淀粉相比,混合淀粉凝胶的脱水缩合率呈下降趋势,表明紫薯淀粉的添加使小麦淀粉凝胶强度增大,凝胶网络结构变致密,所以水分难以从淀粉凝胶网络结构中析出。低场核磁中的结果显示,紫薯淀粉的添加,使小麦淀粉凝胶中的一部分自由水转化为弱结合水,提高了混合凝胶的持水性;凝胶网络结构扫描结果显示,紫薯淀粉的添加使混合淀粉凝胶的孔洞分布均匀且孔洞变小。综合结果表明,紫薯淀粉可增强小麦淀粉凝胶的网络结构,改善小麦淀粉的凝胶特性。
The effects of purple sweet potato starch on the gel properties of wheat starch gel were investigated by texture analyzer,dynamic rheometer,low-field nuclear magnetic resonance(LF-NMR)spectroscopy and scanning electron microscopy.The results of the textural profile analysis showed that the springiness and cohesiveness of wheat starch gel increased,as the proportion of purple sweet potato starch increased in the range of 0% to 15%,especially when the amount of purple sweet potato was 10%,the change was most obviously.Dynamic rheological analysis suggested that with the increase of the proportion level of purple sweet potato starch,both storage modulus(G′)and loss modulus(G″)increased,while loss tangent(tanδ)decreased and was less than 1,which demonstrated stronger solid property of the mixed starch.Moreover,during the freeze-thaw cycle,compared to pure wheat starch,as the amount of purple sweet potato starch increased,the syneresis of the mixed starch gel reflected a downward trend.This result indicated that purple sweet potato starch increased the strength of wheat starch gel and made the gel network structure dense,so it was difficult for water to precipitate out of the network structure of starch.The low-field nuclear magnetic resonance results showed that some free water in the wheat starch gel transformed into weakly bound water by adding purple sweet potato starch,which improved the water-holding capacity of the mixed gel.The scanning electron microscopy images showed that purple sweet potato starch improved the wheat-starch gel network structure,and the pores distributed evenly and became smaller.These results indicated that purple sweet potato starch can enhance the network structure and improve the gel properties of wheat starch gel.
作者
丁燕燕
韦冬梅
许莉
周裔彬
杨丽萍
曹川
DING Yanyan;WEI Dongmei;XU Li;ZHOU Yibin;YANG Liping;CAO Chuan(Anhui Engineering Laboratory for Agro-products Processing,School of Tea&Food Science Technology,Anhui Agricultural University,Hefei 230036;Anhui Vocational College of Grain Engineering,Hefei 230002;School of Food Engineering,Anhui University of Science and Technology,Fengyang 233100)
出处
《安徽农业大学学报》
CAS
CSCD
2020年第5期707-712,共6页
Journal of Anhui Agricultural University
基金
安徽省科技攻关项目(1704a07020098)资助。
关键词
小麦淀粉
紫薯淀粉
混合
凝胶特性
冻融稳定性
wheat starch
purple sweet potato starch
mixture
gel properties
freeze-thaw stability
作者简介
丁燕燕,硕士。E-mail:1582151293@qq.com;通信作者:周裔彬,教授,博士生导师。E-mail:zhouyinbin@ahau.edu.cn。
