【摘要】 以X-射线衍射(XRD)和傅里叶变换红外光谱(FT-IR)研究马铃薯蛋糕在贮藏期间(1、24、72、120、168 h)的老化特性,并利用质构仪和色差研究了老化对蛋糕品质(质构、色差)的影响。结果表明,蛋糕贮藏1 h后,在X-射线2θ12.5°和20°附近出现衍射峰,分别对应于禾谷类淀粉的无定形峰和由直链淀粉与脂肪酸形成的螺旋形复合物——V-型结晶,当贮藏时间达到120 h时,在2θ17°附近出现由支链淀粉回生产生的B-型结晶。FT-IR在波数925、995、1 025、1 047、1 079、1 155和1 243 cm-1附近出现吸收峰,1 025和1 047 cm-1附近的吸收峰分别对应淀粉的非结晶区特征和结晶区特征,(1 047/1 025) cm-1峰强度比值能够反映淀粉分子的有序程度,其比值越大,有序度越高。马铃薯蛋糕在贮藏期间的X-射线衍射峰和红外吸收峰强度以及(1 047/1 025) cm-1比值均小于普通蛋糕,表明其老化速度慢于普通蛋糕。老化会导致蛋糕硬度、咀嚼性、胶着性、a*和b*值增加,黏聚性和L*值降低,从而使蛋糕失去光泽、口感变粗糙、风味发生劣变。更多还原

【Abstract】 The staling characteristics of potato cake during storage(1,24,72,120,168 h) were studied by X-ray diffraction and Fourier transform infrared spectroscopy,additionally,with Texture Analyzer and Color Difference Meter,effects of staling on cake quality(texture and color) were studied. The results manifested that through the X-ray of the potato cake,after 1 h of storage,peaks at around 2θ of 12.5° and 20° arised,namely the amorphous peak of cereal starch and V-type structure which was the helical complex formed by amylose and fatty acids,after 120 h of storage,peaks at around 2θ of 17° showed up which was caused by B-type structure formed by amylopectin starch. The fourier transform infrared spectroscopy of cake samples showed major peaks at around925,995,1 025,1 047,1 079,1 155 and 1 243 cm-1,the IR absorbance bands at 1 025 and 1 047 cm-1 was the amorphous starch and crystalline starch respectively,the band intensity ratio at 1047 and1 025 cm-1 illustrated the order degree of starch,the higher the ratio was,the higher the order degree was. Potato cake had lower X-ray diffraction and IR absorbance bands intensity as well as(1 047/1 025) cm-1 ratio than ordinary cake during storage,suggesting that its staling rate was lower than that of ordinary cake. Aging will lead to cake hardness,chewiness,gumminess, a* and b* values increased,cohesiveness and L* values decreased,making the cake lack of lustre,taste rough with the deterioration of flavor.更多还原