LED单色红光对西兰花采后黄化抑制效果的影响

Effects of Red Light-Emitting Diode(LED)on the Postharvest Yellowing Change of Broccoli

光照是影响植物生长发育的重要因子,在植物生长过程中,对植物的生理代谢、光合特性、品质及衰老均有广泛的调节作用。然而国内外对于采后光照是否仍然可以提高果蔬品质,延长贮藏保鲜期的研究少见报道。采用红、蓝、绿三种单色光照射处理西兰花,红光对采后西兰花花球黄化具有抑制作用,蓝光抑制作用不明显,而绿光则加速了西兰花黄化,因此本文将重点研究LED单色红光对西兰花采后黄化抑制效果。采用波长为625±5nm,光照强度(100±5)Lx的LED单色红光持续照射西兰花花球,以避光处理为对照。结果表明:LED单色红光能够抑制西兰花花球表面色差L值升高,保持色差-a/b值,延缓叶绿素降解;同时能够降低西兰花呼吸强度,推迟呼吸高峰,降低乙烯生成速率,有效保持了西兰花的商品性。相关性分析表明,采用LED单色红光处理后,乙烯生成速率与黄化指数之间达到极显著正相关水平(p<0.01)。与常规无光处理相比,LED单色红光处理延长了西兰花保鲜期5d左右,为西兰花的贮藏保鲜提供理论依据。本文创新点在于首次将无化学污染、环境友好特性的LED单色光引入西兰花采后贮藏保鲜过程中,重点研究了LED单色红光对西兰花采后颜色变化的影响,明确了LED单色红光对西兰花采后黄化具有抑制作用。

As an important factor affecting the growth and development of plants,light gives wide range regulating effects on physiological metabolisms,photosynthesis characteristic,quality and aging of plants during the growth.However,the research whether light can improve the quality of fruits and vegetables and prolong the storage period of is rarely reported home and abroad.Three monochromatic light,red,blue and green were used to the irradiation of broccoli.It was found that the inhibitory effect of red light could inhibit yellowing of postharvest broccoli better than that of blue light while green light could accelerate the yellowing,therefore this paper focused on the yellowing inhibitory effect of LED monochromatic red light on postharvest broccoli.The LED monochromatic red light with wavelength（625±5）nm,light intensity（100±5）Lx was used to provide continuous irradiation to broccoli with no light treatment as control.The results showed that：LED monochromatic light could inhibit the increase of chromatic aberration L value.The chromatic aberration-a/bvalue was maintained and the chlorophyll degradation was delayed.Meanwhile,the broccoli commodity was effectively maintained because of the delay of the respiration peak and the reduction of respiratory intensity as well as ethylene release rate.Correlation analysis showed that,after red LED monochromatic light treatment of broccoli,apositive very significant correlation（p〈0.01）was found between the ethylene release rate and yellowing index.Compared with conventional no-light,treatments of LED monochrome red could extend the storage period around 5dfor broccoli,and the results can provide a theoretical basis for cold storage of Broccoli.