Pulsed light of near-infrared and visible light wavelengths induces the accumulation of carotenoids in tomato fruits during post-treatment time.

Abstract

Pulsed light (PL) is proposed as a novel strategy for the food industry to enhance the antioxidant potential of fruits and vegetables for industrial uses. The main aim of this work is to evaluate the impact of postharvest PL treatments of different spectral ranges on the carotenoid concentration as well as quality attributes of tomatoes during post-treatment time. Doses of wide-spectrum light (180-1100 nm), full-spectrum without ultraviolet (UV)-C wavelengths (305-1100 nm), and visible (VIS) + near-infrared light (NIR) (400-1100 nm) were compared. Total carotenoids, lycopene, and chlorophyll contents were spectrophotometrically assessed just after treatments and 1, 5, and 10 days post-treatment. PL treatments accelerated the accumulation of both total carotenoids and lycopene concentrations in tomato fruits. Nevertheless, the efficacy of PL depended on the applied spectral range. Tomato subjected to VIS + NIR treatment exhibited the greatest enhancement in total carotenoids (31 %) and lycopene (35 %) content at day 5 post-treatment and quality attributes were not affected. Conversely, UV-light exposure did not enhance carotenoid concentrations. These results evidenced that VIS + NIR treatments induced a faster accumulation of carotenoids without negatively affecting tomato quality attributes. PRACTICAL APPLICATION: The integration of visible and near-infrared (VIS + NIR) light filters in pulsed light (PL) processing allows enhancing the accumulation of bioactive compounds in tomato tissues in a sustainable way, which can be processed to obtain derived products (e.g., juices, purees) with health-promoting properties. PL technology is characterized by a lack of residual compounds and the absence of applying chemicals potentially harmful to humans. Industries can attract the attention of consumers through their application, which allows offering this added value.