食品科学 ›› 2020, Vol. 41 ›› Issue (3): 18-23.doi: 10.7506/spkx1002-6630-20190207-032

• 基础研究 • 上一篇    下一篇

复合酶修饰对红薯淀粉分支结构和物化特性的影响

肖瑀,郭丽,邓银凤,王懿,朱晨晨,杜先锋   

  1. (1.安徽农业大学茶与食品科技学院,安徽 合肥 230036;2.齐鲁工业大学(山东省科学院)食品科学与工程学院,山东 济南 250353)
  • 出版日期:2020-02-15 发布日期:2020-02-26
  • 基金资助:
    国家自然科学基金面上项目(31471700;31771933)

Effect of Multi-Enzyme Modification on Branch Structure and Physicochemical Properties of Sweet Potato Starch

XIAO Yu, GUO Li, DENG Yinfeng, WANG Yi, ZHU Chenchen, DU Xianfeng   

  1. (1. School of Tea and Food Science, Anhui Agricultural University, Hefei 230036, China; 2. School of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China)
  • Online:2020-02-15 Published:2020-02-26

摘要: 本实验采用α-淀粉酶、β-淀粉酶和葡萄糖苷转移酶复合修饰天然红薯淀粉,借助高效阴离子交换色谱、质子核磁共振氢谱、X射线衍射以及流变仪分析了红薯淀粉酶解前后的链长分布、分支密度、结晶结构、分支结构和流变特性。结果表明:复合酶处理后,红薯淀粉的短链比例显著增加(P<0.05),平均链长显著降低(P<0.05);当葡萄糖苷转移酶添加量为300 μL时,红薯淀粉的分支密度高达35%,明显高于对照样品;酶改性淀粉晶体结构由C型转化为C+V型,所有酶改性淀粉的相对结晶度均低于天然红薯淀粉,相对结晶度与葡萄糖苷转移酶添加量成正比,从10.8%增加至14.8%;溶解度和透明度相对于对照组明显增大,且分别随葡萄糖苷转移酶添加量的增加而增大,最高值分别可达66.15%和73.91%;表观黏度、储能模量和损耗模量显著低于对照组(P<0.05),均随葡萄糖苷转移酶添加量的增加而降低。研究结果为从分支链结构水平上调控复合酶法改善红薯淀粉的物化特性提供一定的理论和应用依据。

关键词: 复合酶法, 红薯淀粉, 分支密度, 物化特性, 改性??

Abstract: Sweet potato starch was sequentially treated with α-amylase (80 mg), β-amylase (10.6 mg) and different amounts (50, 100, 150, 200, 250 and 300 μL) of transglucosidase. The chain length distribution, branch density, crystal structure and rheological properties of sweet potato starch before and after enzymatic hydrolysis were analyzed by high performance anion-exchange chromatography equipped with pulsed amperometric detection (HPAEC-PAD), proton nuclear magnetic resonance (1H NMR) spectroscopy, X-ray diffraction and rheometry. The results showed that after the enzymatic treatment, the short-chain ratio of sweet potato starch increased significantly (P < 0.05) and the average chain length decreased significantly (P < 0.05), and when 300 μL of transglucosidase was added, the branch density of sweet potato starch was as high as 35%, significantly higher than that of the control sample. The crystal structure was transformed from C type to C + V type after the enzymatic modification. The relative crystallinity of the modified starches was lower than that of the natural starch, which proportionally increased from 10.8% to 14.8% with the amount of transglucosidase added. The solubility and transmittance were significantly higher than those of the control, and they increased with the addition of transglucosidase, reaching the highest value of 66.15% and 73.91%, respectively. The apparent viscosity, storage modulus and loss modulus were significantly lower than those of the control group (P < 0.05), and they all decreased with the addition of transglucosidase. These results provide a theoretical and practical basis for modifying the physicochemical properties of sweet potato starch by a multi-enzymatic method at the level of branch chain structure.

Key words: multi-enzymatic method, sweet potato starch, branch density, physicochemical properties, modification

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