甜玉米米粉滚筒干燥加工工艺优化

Optimization on drum drying processing technology of sweet corn powder

为了解决酶解后的甜玉米滚筒干燥制成的米粉吸水膨胀及感官状态差的问题,该文对甜玉米酶解液经过滚筒干燥制成的甜玉米米粉的加工工艺进行了研究。依据产品吸水性指数和感官评分,确定了糯玉米淀粉作为交联剂,添加量为25%。根据糊化度,滚筒干燥效果,确定了糊化温度85℃、糊化时间30min。并且在单因素试验的基础上进行了三因素三水平的响应面试验设计,以甜玉米酶解液质量分数、蒸汽压力、滚筒转速为考察因素,以吸水指数和感官评分为考察指标,对试验数据拟合得到的回归方程进行统计检验和分析。较佳滚筒干燥条件为:甜玉米酶解液质量分数17%、蒸汽压力0.5MPa、滚筒转速2.5r/min。在此试验条件下,产品的感官评分为8.75分,吸水指数为5.3,并在此条件下进行多次验证试验,试验值在95%的置信区间内很好地符合预测值,为工业化生产婴儿甜玉米米粉提供指导。

According to the problems of imbibition and poor sensory state of the sweet corn flour by the drum drying from enzymolysis sweet corn, the processing technology of modified sweet corn powder made by sweet corn pulp was studied. Based on water injectivity index and sensory evaluation, the waxy maize starch was used as cross-linking agent with optimal dosage of 25%. According to gelatinization degree and effect of drum drying, the optimum gelatinization temperature was 85 ℃ and the gelatinization time was 30min. On the basis of the results of single factor experiment, response surface experiment of three factors and three levels was designed. Concentration of modified sweet corn pulp, steam pressure, rotate speed of the drum were investigated, and taking water absorption index and sensory evaluation as indexes, a regression equation was derived from the data obtained and the results were analyzed by statistic methods. The optimum drum drying conditions were as following： concentration of modified sweet corn syrup was 17%; steam pressure was 0.5 MPa; rotate speed of the drum was 2.5 r/min. Under these conditions, sensory score of drum drying product was 8.75, water absorption index was 5.3. Verification tests showed that all values were within 95% confidence limits. The results are in conformity with the anticipation, which can provide a guidance for industrialized production of sweet corn flour for infants.