高浓度CO2对香蕉和大蕉后熟及果皮叶绿素降解的影响

摘要

以香蕉和大蕉为试材,在20％ CO2+21％ O2气调环境和20℃的后熟条件下,通过测定叶绿素含量、果实硬度、细胞膜透性、丙二醛含量、叶绿素酶和脱镁螯合酶活力来研究高浓度CO2对香蕉和大蕉后熟和果皮叶绿素降解的影响.结果表明:20％ CO2对香蕉和大蕉的后熟和叶绿素b含量均无显著影响,但对叶绿素a含量的影响不同,相比于大蕉,香蕉果皮叶绿素a的降解受到明显抑制;叶绿素酶不是香蕉和大蕉叶绿素降解的关键酶;20％ CO2明显抑制了香蕉脱镁螯合酶的活力,但大蕉脱镁螯合酶的活力反而提高,脱镁螯合酶是香蕉叶绿素降解过程中的关键酶.可见,相比于大蕉,香蕉果皮的褪绿更容易受到高浓度CO2的贮藏环境的影响.%Taking banana and plantain fruits as materials,ripening at 20％ CO2 + 21％ O2 air environment and 20 ℃,the chlorophyll content,fruit firmness,membrane permeability,MDA content,chlorophyllase and Mg-dechelatase activity were determined to study the effect of high CO2 on the ripening and chlorophyll degradation of banana and plantain fruits.The results showed that no significant influence of 20％ CO2 on ripening and Chl b content of banana and plantain fruits,however,20％ CO2 conferred different effects on Chl a content,compared with plantain,the Chl a in banana peels degradation was significantly inhibited.Chlorophyllase was not a key enzyme of chlorophyll degradation in banana and plantain peels.In banana peels the MDCase activity was inhibited,while in plantain peels the MDCase activity was improved,MDCase was a key enzyme of chlorophyll degradation in banana peels.These findings suggest that the degreening of the banana peel was more likely to be inhibited than plantain when stored at high CO2.