Specific wavelength LED light pulses modify Vitamin C and organic acids content in raspberry and blackberry fruit during postharvest

Abstract

Light-emitting diodes (LED) have emerged as a non-polluting and energy-saving technology in fruit postharvest. The aim of this work was to evaluate the effect of different LED light pulses during raspberries´ and blackberries´ postharvest under cold storage. Fruit was exposed to short LED light pulses (Green, Blue, Red, and Red+Blue) of 15 min every 2 h for 7 and 14 d of storage at 4°C. Raspberries were more susceptible to water loss. Short LED light pulses decreased internal breakdown in raspberries, and minor effects of LED treatments were observed in blackberries. After 7 d of cold storage, in raspberries, Green, Blue, and Red light treatments increased the content of quinic and malic acids, and only Green and Blue LED sources also increased ascorbic acid content. In addition, Blue, Green, and Blue+Red LED light treatments exhibited a higher level of citric acid at 14 d. In blackberries, fruit changes were mainly because of the cold storage. Overall, these results showed that short LED light pulses can extend the postharvest life of raspberries, decreasing internal breakdown and increasing the content of ascorbic acid, suggesting that different Rubus species have distinct physiological processes underlying ripening and light interactions.