采用顶空分析仪和色度计,对储藏期内室温(23 ℃)和冷藏(4 ℃)下袋内西兰花的生命变化(外观色泽和气氛)进行了监测。结果发现,随着储藏天数的增加,包装袋内气氛中O2 浓度逐渐降低,CO2 浓度逐渐增加,西兰花的色度(a 和b)和明度(L)值逐渐增加。这表明西兰花的外观颜色由蓝变黄,由绿变红,明度由黑变白。此外,储藏温度强烈影响西兰花的生命变化。与室温23 ℃相比,4 ℃冷藏下西兰花的L,a,b 值及袋中O2 和CO2 浓度的下降幅度有所减缓,这表明西兰花的外观色泽得到一定的保持,且呼吸作用得到抑制,因此4 ℃冷藏对西兰花具有保鲜作用。色度计和顶空分析仪可作为保鲜研究中的有力工具去研究果蔬的生命变化。

Life changes of broccoli in package under ambient (23 ℃) and refrigerated (4 ℃) storage was observed by headspace analyzer and colorimeter. It was found that the chroma (a and b value) and lightness (L value) of broccoli increases with elevation of storage time; at the same time, the concentration of oxygen in bags drops and that of carbon dioxide rises. It indicated that the color has changed from blue to yellow and from green to red, and the lightness has changed from black to white; the life change is strongly influenced by storage temperature. The broccoli at 4 ℃has longer shelf life due to the better color appearance and lower respiration in storage period, compared with that stored at room temperature of 23 ℃. Headspace analyzer and colorimeter are helpful tools in fresh-keeping field by monitoring precisely the life change of fruits and vegetables.