While continuous white LED lighting increases chlorophyll content (SPAD), green LED light reduces the infection rate of lettuce during storage and shelf-life conditions

Abstract

The aim of this study is to prevent postharvest quality losses and enhance storage and shelf life of leaf lettuce using LED light treatments. For this purpose, four different colors of (white, green, red, and blue) LED light and darkness conditions were used. Lettuce was stored at a temperature of 5 °C ± 1 °C for 21 days, and after storage, it was kept at room temperature for 96 hr. This study demonstrated that white LED light showed up the best application in terms of maintaining green color, reducing chlorophyll degradation, and increasing the total soluble solid content of lettuce. While the weight loss was reduced by red LED light treatment, the green LED light was effective in reducing the decay rate of lettuce. It was concluded that white, red and green LED lighting treatments are useful for enhancing the storage life of leaf lettuce, whereas the blue LED light treatment showed negative effects. Practical applications Light-emitting diodes (LEDs) is used in horticultural production to increase yield by photosynthesis over decades. In postharvest storage stage, lighting of LED provided some advantages such as reducing of the growth of microorganism, especially citrus varieties. Leafy vegetables are identified susceptible because it contains large amount of water. Also they lose their green color very quickly after harvest. So, postharvest storage life of these type vegetable is quite short. As a result of the present study, chlorophyll (SPAD) content of leaf lettuce was increased by white LED light treatment both during storage and shelf life conditions. Therefore, by this technology, the shelf life of leaf lettuce would be increased by lighting of shelf in the supermarket by white LED, at least.