【作者】 贺丽霞；

【导师】 王敏； 黄忠民；

【作者基本信息】 西北农林科技大学 ， 食品工程， 2011， 硕士

【摘要】 为了更快速简便地将小麦面坯(片)进行品质在线测定和综合分类,满足工业化生产的实际需求,本研究以11种原小麦面粉和2种市售的小麦面粉为材料,采用谷物近红外分析方法对面粉的基本指标含量进行测定;运用粉质测定方法对面团的流变性进行测定;采用质构穿透的方法对面片的韧性和延展性进行了测定;采用质构剖面分析方法(texture profile analysis,简称TPA)对面坯、淀粉凝胶和面筋进行了测定。研究首先通过面片突破实验的测试,用小麦面片的韧性和延展性作为衡量指标,对小麦面粉的工艺进行确认。然后再利用相关分析和主成分-逐步回归分析寻求三种小麦粉品质测定方法之间的相关性,突出了质构测定的可实现性。最后运用聚类分析的手段,从两方面对所测定的面粉进行分类,对质构检测小麦面坯(片)的手段进行了评价。研究结果表明:(1)加水量、加盐量、揉面时间和醒面时间等因素对面片韧性和延展性都具有一定的影响。结合实际工业化生产需求,得出了各个单因素的最适工艺参数,即加水量50%(面粉干基)、加盐量2%、揉面时间为5min、醒面时间为10min。(2)谷物近红外检测、质构测定与粉质特性之间存在着一定的相关关系,粉质测定的吸水率与质构特性中的咀嚼性呈显著性相关,和质构特性中的粘着性、回复性,近红外测试中的水分含量、颗粒度、吸水率、沉降值的相关性呈极显著,相关系数r分别达到0.82、0.78、-0.68、0.88、0.80和-0.79;形成时间与质构检测中的粘性、近红外检测蛋白质含量呈显著性正相关,与沉降值呈显著性负相关,与质构中的粘着性、近红外检测的水分含量、颗粒度和吸水率呈极显著相关,相关系数r分别达到0.69、-0.73、0.79和0.72;稳定时间只与质构检测的延展性和粘着性呈显著性相关;弱化度与质构测定的粘性、延展性和粘着性呈负相关,其中与粘性的相关性极显著,相关系数r=-0.70;评价值与质构中的延展性、近红外检测中的水分含量、颗粒和吸水率显著性相关,其中评价值与水分含量呈负相关,除此之外,评价值与质构测试中的粘性、粘着性的相关性极显著,相关系数r分别为0.69和0.78。(3)逐步回归分析中,将小麦粉近红外成分含量测定和质构分析中得到的14项指标作为预测变量引入回归模型进行逐步回归分析,同时采用主成分分析消除预测变量间的多重共线性,构建了具有统计意义的吸水率、形成时间、稳定时间、弱化度和评价值的预测模型(P<0.0001),其中决定系数为0.997的吸水率模型使预测效果达到接近完美的水平。(4)TPA测定淀粉凝胶的弹性、黏聚性、胶着性、咀嚼性和回复性都与面坯的粘性有着显著或者极显著的关系。相关系数r分别达到-0.66、-0.61、-0.58、-0.67和-0.66。以上表明,面坯粘性和淀粉凝胶的弹性、黏聚性、胶着性、咀嚼性和回复性全部呈负相关,其中淀粉凝胶的咀嚼性、回复性和面坯的粘性呈极显著负相关。TPA测定的面筋质构特性和面坯质构特性大部分不存在相关性。仅有面筋的粘性和面团弹性、黏聚性呈负相关性,相关系数r分别为-0.56和-0.80。其中面团的黏聚性和面筋的粘性呈极显著负相关性。(5)通过以不同的质构指标为变量的面坯(片)聚类分析,得到了两组近似程度超过50%的不同分类组,证明了通过质构分析对面坯(片)品质的控制和分类是存在一定的可靠性的。但是由于样本量和实验误差的问题,实验还是存在一些有待解决的问题。更多还原

【Abstract】 In order to detect quality of wheat dough (film) online, compressively assort them more quickly and easily, and meet the actual needs of industrial production, 11 original wheat flour and two kinds of commercial flour were selected as materials to determine the basic indicators of the flour contents by the grain near infrared method; measure rheology of dough by farinograph; determine the texture properties by breakthrough test of the film; determine the texture properties of dough, starch gel and gluten by texture profile analysis (texture profile analysis, TPA). In this paper, the process of wheat flour as a measure with toughness and extension of breakthrough experiment were confirmed. Then analysing the correlation among three kinds of flours’detections by correlation analysis and principal component - stepwise regression analysis and highlighting the realization of texture. Finally, cluster analysis by using two different methods to evaluate texture analysis was conducted. The paper showed:(1) The amount of water, salt content, dough kneading time and proofing time can impact the toughness and extension of dough. For meeting the actual industrial production needs, we obtained process parameters of single factors, the amount of water was 50% of dry flour, salt was 2%, kneading time was 5min and the proofing time of 10min.(2) There was a certain correlation among the grain near infrared detection, farinograph and texture, water absorption by NIRS was significant correlation with the chewing of texture properties, and was very significant correlation with the adhesiveness, resilience of texture properties recovery, water content, particle size, water absorption, zeleny by NIRS, r values were 0.82, 0.78, -0.68, 0.88, 0.80 and -0.79, respectively; formation time and viscosity of texture, protein content tested by near-infrared detection were significantly correlated, and was significantly negatively correlated with sedimentation value, adhesive of texture, moisture content, particle size and water absorption by NIRS with r values 0.69, -0.73, 0.79 and 0.72, respectively; stabilization time was only significantly related with the extension and adhesion in texture properties; the degree of softening was negatively correlated with viscous, extension and adhesion, correlation coefficient was -0.70; there were significantly correlated among evaluation value, extension and moisture content, particle and water absorption. In addition, evaluation values was negatively correlated with moisture content, and the viscous tested by texture, and r values were 0.69 and 0.78, respectively. (3) In stepwise regression analysis, 14 indicators of component of wheat flour and the texture were as predictor variables into regression model stepwise regression analysis, and forecasting using principal component analysis to eliminate multicollinearity among the variables. The prediction model of water absorption, development time, stability time, degree of softening and evaluation were constructed with statistical significance (P <0.0001), in which the water absorption coefficient of determination was 0.997, nearly achieved perfect level.(4) Elasticity, cohesiveness, gumminess, chewiness and resilience of starch gel by TPA determination were related to the viscosity of the dough and there was a significant or very significant relationship. Correlation coefficient were -0.66, -0.61, -0.58, -0.67 and -0.66, respectively. Above that, dough stickiness and elasticity, cohesiveness, gumminess, chewiness and resilience of starch gel were negatively related to all, including the chewing of starch gel, recovery and sticky dough. Most of the correlation among textural properties determination of gluten and dough textural properties does not exist. Only gluten and elasticity viscosity cohesiveness of dough were negative correlation, r = -0.56 and -0.80. And the cohesion of dough and gluten viscosity was significantly negatively correlated.(5) Through cluster analysis using the different indicators for the variable texture of dough (film), it was found that two groups were more similar than 50%, and it was confirmed that texture analysis had reliability. However, there are some problems due to the sample size and experimental error which need to be solved in future.更多还原