The effect of red and violet light emitting diode (LED) treatments on the postharvest quality and biodiversity of fresh-cut pakchoi (Brassica rapa L. Chinensis).

The effects of red and violet Light Emitting Diode (LED) irradiation on the quality changes of fresh cut pakchoi (Brassica rapa L.Chinensis), such as water migration, soluble solids, chlorophyll, ASA, shelf life, antioxidant enzyme activity and changes of biodiversity were evaluated in this study using physicochemical and high-throughput sequencing analys. The results showed that red and violet LED irradiation (15 μ mol/(m2 · s)) (1) are significantly inhibited the changes of sensory evaluation, (2) increased the content of chlorophyll, ASA and antioxidant enzymes, and (3) prolonged the shelf life of pakchoi at 4 °C. Furthermore, through the using of high-throughput sequencing, aerobic plate count and the count of Pseudomonas spp., it was found that (4) red and violet LED changed the microbial community structure among samples, and inhibited the reproduction of specific spoilage organism (SSO) in fresh cut pakchoi. At the same time, compared with the traditional sterilization method, the results showed that visible light sterilization was also effective. In general, the results showed that LED treatment was an effective way to delay the senescence and maintain the quality of the pakchoi by enhancing the activity of antioxidant enzymes and regulating chlorophyll and ASA metabolism, inhibited the reproduction of SSO.