超声辅助烫漂对黄花菜干制品色泽的影响

为探究不同漂烫温度及超声辅助漂烫预处理对黄花菜干制品色泽的影响，分别在70、80、90 ℃三种温度下烫漂及超声辅助烫漂对黄花菜进行预处理，然后对预处理所得干制品褐变度、色泽、抗坏血酸、叶绿素及5-羟甲基糠醛含量等指标进行测定。结果表明：随着漂烫温度升高，预处理时间变短，抗坏血酸含量和叶绿素含量提高，褐变度与5-羟甲基糠醛含量降低，产品色泽较好。与普通烫漂处理相比，经功率密度为0.4 W/cm2超声烫漂处理后干燥所得的产品抗坏血酸含量和叶绿素含量显著升高（p<0.05），褐变度与5-羟甲基糠醛含量显著降低（p<0.05），色泽更好。烫漂温度为90 ℃、功率密度为0.4 W/cm2时超声预处理的干制品抗坏血酸和叶绿素含量最高，分别为0.4067 mg/g和0.87 mg/g，而褐变度、5-羟甲基糠醛含量显著降低（p<0.05），色泽最好。
The effects of blanching and ultrasonic-assisted blanching on the color quality of dried daylily flower were studied. At temperatures of 70, 80, and 90 ℃, the daylily flowers were pretreated by blanching or ultrasonic-assisted blanching, and the browning degree; color; content of ascorbic acid, chlorophyll, and 5-hydroxymethylfurfural; and other quality indicators of the dried products were analyzed. The results showed that with increasing temperature and decreasing pretreatment time, the content of ascorbic acid and chlorophyll increased, browning degree and 5-hydroxymethylfurfural content decreased, and color was relatively preserved. Compared with the blanched products, the products treated with an ultrasound at a power density of 0.4 W/cm2 showed significantly higher content of ascorbic acid and chlorophyll, significantly lower (p<0.05) browning degree and 5-hydroxymethylfurfural content (p<0.05), and better color. The products treated using ultrasound at 0.4 W/cm2 and 90 ℃ showed the highest content of ascorbic acid and chlorophyll (0.4067 mg/g and 0.87 mg/g, respectively), obvious decreases (p<0.05) in browning degree and 5-hydroxymethylfurfural content, and the best color quality.