Blue LED light improves the antioxidant composition of Valencia oranges during postharvest: Impact on orange juice, pulp portion and peel residue

Abstract

Valencia orange is the major citrus fruit produced worldwide and its outstanding health benefits are well-established. However, there is a pressing need to further enhance the nutritional quality of fruits and to revalorize the resulting residues, providing benefits for both public health and the environment. Here, Valencia oranges were exposed to blue LED light for 30 days at room temperature in controlled environment chambers, using darkness as a control. Examination of the blue LED light effects was performed focusing on visual aspects, weight loss, organoleptic properties, antioxidant content and oxidation status, together with the analysis of the phytohormonal profile. Blue LED light was found to boost fruit weight loss, particularly through dehydration of the peel, without altering pulp firmness or external appearance. Organoleptic quality, including texture and flavor, as well as total soluble sugar and acidity remained unchanged. Notably, blue LED light increased antioxidant levels, more specifically vitamin C and total phenols in the juice, and enhanced total antioxidant capacity in the peel. This suggests that blue LED light can enhance nutritional quality while preserving organoleptic properties. The increase in antioxidants is likely a protective response against photooxidative stress induced by the blue LED light. These findings highlight the potential of blue LED light to improve postharvest fruit quality with direct health benefits and support a circular economy by enhancing the value of orange peel waste.