紫薯馒头的加工工艺优化

Optimization of Processing Technology of Purple Sweet Potato Steamed Bread

紫薯营养价值高,含有丰富氨基酸,尤其是赖氨酸,可与小麦粉优势互补,制作紫薯馒头可以增强食品的营养价值,改善营养构成。试验采用单因素试验设计,设置不同的紫薯粉添加量(0～25%)、酵母粉添加量(1.0～1.8 g)以及发酵时间(1～3 h),分析不同条件下面团特性及馒头质构,以优化紫薯馒头的加工工艺。结果表明,随着紫薯粉添加量的增加,与小麦粉的混合物粉质稳定时间先增加后减弱,其吸水率和弱化度显著提高,面团的延伸度、抗延伸阻力、拉伸比、能量均有降低,馒头的硬度和咀嚼性呈现先减小后增加的趋势,其添加量以10%～15%为宜;随着酵母粉添加量的增加、发酵时间的延长,紫薯馒头硬度和咀嚼性均呈降低趋势,当酵母添加量为1.4 g,发酵时间为2 h时,馒头弹性和回复性最好。最终确定紫薯馒头的优化生产工艺为:每100 g混合面粉中加入紫薯粉10～15 g,小麦粉85～90 g,酵母粉1.4 g,控制发酵时间2 h,生产的馒头品质最好。

Purple potato has high nutritional value and is rich in amino acids,especially lysine,which can complement the disadvantages of wheat flour.Purple sweet potato steamed bread can enhance the nutritional value of food.The experiment was conducted with single factor experiment design,different purple potato powder addition amount(0~25%),yeast powder addition amount(1.0~1.8 g)and fermentation time(1~3 h)were set,the dough characteristics and steamed bread texture in each treatment were analyzed,in order to optimize the processing technology of purple potato steamed bread.The results showed that with the increase of the amount of purple sweet potato powder,the stabilizing time of the mixture with wheat flour increased first and then decreased,the water absorption and weakening degree were significantly improved,the dough elongation,elongation resistance,stretch ratio and energy were all decreased,the hardness and chewiness of the steamed bread decreased first and then increased,the optimal added amount was 10%~15%.With the increase of yeast powder and the prolongation of fermentation time,the hardness and chewiness of purple steamed bread were both decreased,the optimal yeast dosage and the fermentation time was 1.4 g and 2 h,respectively,which the elasticity and recovery of steamed bread were the best.The optimal production process of purple sweet potato steamed bread was determined as follows:each 100 g mixed powder including purple sweet potato powder 10~15 g and wheat flour 85~90 g,adding yeast powder 1.4 g,the fermentation time was controlled for 2 hours,which the quality of the steamed bread was the best.