糯小麦粉配粉对小麦加工品质的影响(Ⅰ)对理化特性的影响

Flour Blending with Waxy Wheat Flour(Ⅰ) Effect on Physicochemical Properties

通过对2种糯小麦和3种非糯小麦理化特性进行比较研究,并利用其中1种糯小麦与非糯小麦配粉,研究其对配粉理化特性的影响。结果表明:糯小麦制粉过程中产生的破损淀粉含量更高,具有极高的吸水能力;在RVA糊化过程中具有较短的峰值时间,低的回生值和低谷黏度,以及较高的衰减值;在DSC测试中还表现出较高的热力学转变温度和糊化焓。糯小麦粉的添加对配粉理化特性的影响因基础粉的不同而有较大差异。配粉的RVA曲线表现为双峰,回生值显著降低;一定比例的添加能够提高峰值黏度低的基础粉的峰值黏度;添加糯小麦粉对弱筋小麦粉的筋力影响较小,其粉力甚至因为面团延伸性的改善而得到增强;对于筋力较强的小麦粉,超过15%的添加量则会使稳定时间降低,但是对粉力的影响不大;添加韧性和延伸性都较低的糯小麦粉,能够提高配粉的吹泡延伸性而不降低其韧性,其原因有待于进一步研究。

Waxy wheat has unique physicochemical properties. Two waxy wheat varieties and three non -waxy wheat samples were used in this work to study the difference between the two wheat categories. One of the waxy wheat samples, Zhongnuo 1, was blended with two non - waxy wheat samples to investigate the influence of waxy flour to the physicochemical properties of blended flour. Results show that waxy wheat starch is damaged more during milling, inducing high flour water absorption. The waxy flour needs shorter time to reach peak viscosity and has lower set- back, lower holding viscosity and higher breakdown than normal flour in RVA test. The endothermic transition tem- peratures and enthalpy of gelatinization of waxy flour, determined by DSC, are significantly higher. The effects of blending with waxy flour on physicochemical properties are different due to the quality of base flour except some con- sistencies including the two peaks and lower setback viscosity of blended flours in RVA profile. Blending with waxy flour at certain ratio increases the peak viscosity of base flour with low peak viscosity. Waxy flour blending does not impact the gluten strength of base flour with weak gluten. The stability time of base flour with strong gluten is declined when waxy flour blending rate is higher than 15%, but no significant decline on W value of Alveograph. The reason of the blending of waxy flour with low P value and low L value could improve the L value and at least not decrease the P value of base flour should be paied more attention for further study.