黑玉米全粉对小麦面团流变学特性及酥性饼干品质的影响

为了拓宽黑玉米全粉在烘焙食品领域的应用,将黑玉米全粉以0~50%的比例替代强中筋小麦粉,利用黏度仪、粉质及拉伸仪等研究黑玉米全粉替代对小麦粉理化特性及面团热机械特性的影响;利用质构仪、感官评价研究黑玉米全粉替代对酥性饼干品质特性的影响。结果表明,黑玉米全粉的加入对面筋网络结构起到阻隔和断裂作用,湿面筋含量及沉降值分别下降了73.2%、71.0%,面团筋度显著降低。黑玉米全粉替代显著改变了面团的流变学特性,面团形成时间、稳定时间下降,弱化度升高;拉伸能量、延伸度、最大拉伸阻力下降,面团强度、稳定性及耐搅拌性降低,加工性能劣化。黑玉米全粉替代小麦粉酥性饼干的延展因子、质构特性及感官评价指标综合分析结果显示,20%黑玉米全粉添加量的饼干延展因子最大,组织结构细密均匀,表面光滑无裂纹,咀嚼性及硬度最大,酥脆性最好,口感最佳。黑玉米全粉酥性饼干常温下6个月保质期内水分、酸价、过氧化值及菌群总数、大肠菌群、霉菌、致病菌指标都符合国家标准。20%的黑玉米全粉添加量使得小麦粉面团在筋度适当下降的同时获得具有黑玉米风味、口感较好的酥性饼干,该研究可为黑玉米全粉在食品加工行业的应用提供理论依据。

Effects of Black Corn Flour on the Rheological Properties of Wheat Dough and the Quality of Crispy Biscuits

In order to widen the application of black corn flour in baking food field,the ratio of 0 to 50% of black corn flour was used to replace strong and medium gluten wheat flour.Viscosimeter,Farinograph and stretcher were used to study the physicochemical properties of black corn flour and the thermomechanical properties of dough.Texture analyzer and sensory evaluation were used to study the effect of black corn flour.substitution on the quality characteristics of crispy biscuits.The results showed that the addition of black maize flour could block and break the network structure of gluten.The wet gluten content and sedimentation value decreased by 73.2% and 71.0% respectively,and the gluten strength of dough decreased significantly.Black corn flour substitution significantly changed the rheological properties of dough,the dough formation time,stability time decreased,weakening degree increased;tensile energy,elongation,maximum tensile resistance decreased;dough strength,stability and stirring resistance decreased,and processing performance deteriorated.The comprehensive analysis results of extension factors,texture characteristics and sensory evaluation indicators of black corn flour instead of wheat flour crispy biscuits showed that the biscuits with 20% black corn flour had the largest extension factors,fine and uniform structure,smooth surface without cracks,the greatest chewiness and hardness,the best crispness and the best taste.The water content,acid value,peroxide value,total bacterial flora,coliform flora,fungi and pathogenic bacteria indicators of black corn crispy biscuit during its shelf life of 6 months at room temperature all conform to the national standard.The addition of 20% black corn flour makes the gluten strengh of wheat flour dough decreased and get crisp biscuits with black corn flavor and good taste at the same time,which can provide theoretical basis for the application of black corn flour in food processing industry.