不同单色LED对低温贮藏西兰花的保鲜作用

为改善西兰花的采后贮藏品质,以期为蔬菜保鲜的实际应用提供新思路。本文研究了低温下不同波长的单色发光二极管(lighting-emitting diode,LED)对西兰花品质的保鲜作用。本研究采用了红光(642 nm)、黄光(591 nm)、绿光(519 nm)、蓝光(464nm)、紫光(435nm)不同波长的单色LED照射西兰花,光照时间24h/d,并从感官、理化、营养和微生物指标综合评价分析不同单色LED对西兰花不同贮藏时期品质的影响。结果表明:不同单色LED光照能延缓西兰花在贮藏过程中营养品质的下降。贮藏12 d后,绿光LED(519 nm)能够最大程度地保持西兰花的感官品质,抑制亮度L*的增加,延缓叶绿素、还原糖及可溶性固形物的降解,同时能够有效地抑制微生物的增长速度,延缓色相角度H值的降低、保持维生素C的含量。因此,绿光LED照射对于西兰花的低温贮藏品质的保持效果最佳,从而延长西兰花的贮藏期。

Preservative Effect of Different Monochromatic Light-emitting Diode (LED) Treatments on Broccoli (Brassica oleracea) in Low-temperature Storage

In order to improve the post-harvest storage quality of broccoli (Brassica oleracea), and provide new approaches for preservation of fresh vegetables in practice, this research examined the preservative effects of different wavelengths of monochromatic light-emitting diode (LED) on the quality of broccoli stored at a low temperature: Red (642 nm), yellow (591 nm), green (519 nm), blue (464 nm), and purple (435 nm); treatment time 24 h/day ? 12 day dark conditions used as a control. A comprehensive evaluation was conducted based on sensory, physico-chemical, nutritional and microbial analyses (including color attributes, chlorophyll content, reducing sugar content, total soluble solid content, and total number of colonies),to assess the post-harvest storage quality of broccoli over the storage. Results showed that different monochromatic LED treatments could delay the decline of nutritional quality of broccoli during storage. After 12 days of storage, the green LED (519 nm) could maximally maintain the sensory quality of broccoli, inhibit the increase of brightness L*, delay the degradation of chlorophyll, reducing sugar and soluble solids, and in the meantime, suppress effectively the microbial growth, delay the decrease of hue angle (H-value) and maintain the content of vitamin C. Therefore, the green LED treatment was the most effective to maintain the storage quality of broccoli over the low-temperature storage and extend its shelf life.