预处理方式对热风干燥玫瑰花瓣品质特性的影响

Effects of different pretreatment methods on the quality characteristics of red rose by hot air drying

采用5%柠檬酸溶液、20%糖溶液、20%NaCl和柠檬酸混合溶液浸渍、烫漂4种处理方式处理玫瑰花瓣,以未预处理的花瓣作为对照,进行热风干燥对比试验和分析,对花瓣品质特性(色泽、总黄酮含量、总酚含量)以及微观结构等进行比较,并结合模糊数学综合评判法进行感官评定。结果表明:预处理方式对玫瑰花瓣的干燥速率有显著影响,且在含水率较高时尤其明显;微观结构有一定的差异性。其中,5%柠檬酸溶液组耗时最长,ΔE最小;20%糖溶液组复水比最低;混合溶液组色泽变化ΔE最大,总酚含量最高;烫漂组耗时最短,总黄酮含量和复水比最高。经烫漂预处理后的花瓣干燥后得到的感官评分值最高,对应的干燥时间、ΔE、复水比、总黄酮含量及总酚含量分别为120min、18.17±0.54、3.01、0.27mg/g、1.43mg/g。因此,采用烫漂预作为预处理方式可以提高食用玫瑰花瓣干制品的品质。

In order to understand the effect of different pretreatments on the hot air drying characteristics and quality of red rose,four different pretreatment methods,i.e.impregnated 5%citric acid solution,20%sugar solution,20%NaCl and citric acid mixed solution and blanching,the pretreated petals were used as the control,to conduct comparative experiments and a-nalysis of hot air drying.Sensory properties(color,total fla-vonoids,total phenols)and microstructure of red rose were examined,and combined with fuzzy mathematical comprehensive evaluation method for sensory evaluation.The results showed that drying rate of rose petals was influenced significantly by different pretreatment methods especialfy when the moisture content was high,and there are certain differences in microstructure.The dried red rose products in the 5%citric acid solution pretreatment group required the longest time and the lowest color difference indexΔE;in the 20%sugar solution group,the rehydration ratio was lowest.In the 20%NaCl and citric acid mixed solution group,the highest color difference indexΔE and the highest content of total phenols.The blanching pretreatment group required the shortest time,obtained the highest content of total flavonoids and the highest rehydration ratio.The blanching pretreatment group had the highest sensory score.Under the optimized condition,the drying time,and the color difference indexΔE and the content of total flavonoids and total phenols were 120 min,18.17±0.54,3.01,0.27 mg/g and 1.43 mg/g,respectively.Therefore,the application of blanching as a pretreatment method could improve the quality of dried red rose products.