部分水解瓜尔胶的酶法制备及其对面包烘焙特性的影响

Enzymatic Preparation of Partially Hydrolyzed Guar Gum and Its Effect on Baking Characteristics of Bread

为研究部分水解瓜尔胶(partially hydrolyzed guar gum,PHGG)对面包烘焙特性的影响,以瓜尔胶(guar gum,GG)为原料,采用酶解法制备PHGG。在比较PHGG和GG基本组成差异的基础上,采用质构仪、低场核磁共振仪、差示扫描量热仪和九分嗜好评分法研究PHGG添加量对面包烘焙品质及储藏特性的影响。基本组成分析结果表明,与GG相比,PHGG的黏度和分子质量显著下降,分别为(118.80±0.62)mPa·s、8.1 kDa。烘焙品质分析结果表明,添加PHGG对面包比容无显著影响,但可显著降低面包的烘焙损失率,从(14.08±0.77)%降低至(11.73±1.29)%;并赋予了面包更好的色泽。面包储藏特性研究结果表明:在7 d储藏期内,PHGG显著提高了面包的保水率,从(77.48±0.43)%增加至(85.58±4.15)%;改善了面包的内聚性和回复性;促进了面包内部水分的迁移,进而增加了面包内部结构的稳定性,具有延缓面包老化的效果。此外,感官评价结果表明,PHGG添加组面包的感官评分高于对照组面包。PHGG添加量(质量分数)为2.5%~4.5%时可显著改善面包的烘焙品质、储藏特性和感官品质,研究旨在为PHGG在食品加工中的应用提供一定理论参考。

In order to study the effect of partially hydrolyzed guar gum(PHGG)on the baking characteristics of bread,PHGG was prepared by enzymatic hydrolysis method with guar gum(GG)as raw material.Based on the comparison of basic composition differences between PHGG and GG,the effects of PHGG dosage on the baking quality and storage characteristics of bread were studied by texture analyzer,low field nuclear magnetic resonance analyzer,differential scanning calorimeter and nine-point hobby score.The results of basic composition analysis showed that the viscosity and molecular weight of PHGG decreased significantly compared with GG,which were(118.80±0.62)mPa·s and 8.1 kDa,respectively.The analysis of baking quality showed that the addition of PHGG had no significant effect on the specific volume of bread,and the baking loss rate of bread was significantly reduced from(14.08±0.77)%to(11.73±1.29)%.The color of bread was also improved.The results of storage characteristics of bread indicated that,PHGG significantly increased the water retention rate of bread from(77.48±0.43)%to(85.58±4.15)%during the 7 d storage period.PHGG also improved the cohesiveness and resilience of bread.It also promoted the migration of water inside the bread,thereby increasing the stability of the internal structure of the bread,and had the effect of delaying the aging of the bread.In addition,the results of sensory evaluation showed that the sensory score of the bread in the PHGG group was higher than that of the control group.The baking quality,storage characteristics and sensory quality of bread could be significantly improved when the PHGG dosage was 2.5%-4.5%,which was expected to provide some reference for the application of PHGG in food processing.