Quality Changes of Fresh-Cut Watermelon During Storage as Affected by Cut Intensity and UV-C Pre-treatment

© 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.The effect of a UV-C (0, 2.4, 4.8 and 7.2 kJ m¿2) pre-treatment was studied during storage at 5 °C on quality changes of fresh-cut watermelon cylinders with different cut intensities (2.7 cm Ø; 1, 2, 4 or 8 cm length). The steady state of the modified atmosphere was reached on day 4 with 4.5¿9.6 kPa CO2 + 14 kPa O2. UV-C treatments were more effective against enterobacteria since enterobacteria counts were better preserved during storage in 4 and 8 cm cylinders under 7.2 kJ m¿2. The longest shelf life (7 days), based on sensory quality, was established for the biggest cylinders (8 cm) treated with 4.8 kJ m¿2, while it was reduced to 5 days for the remaining UV-C doses, regardless of the cut intensity. Lycopene content (52.1¿75.3 mg kg¿1) was not affected by radiation treatments. After UV-C illumination, initial total phenolic contents (387¿508 mg kg¿1) were reduced, reporting less reductions for higher cut intensities. Initial total antioxidant capacity (1.32¿2.44 mmol kg¿1), mainly due to phenolic compounds and lycopene, was decreased after UV-C treatments. Total antioxidant capacity of UV-C samples was increased (2- to 14-fold) compared with untreated samples throughout storage as an antioxidant response of UV-stressed samples. Conclusively, fresh-cut watermelon cylinders of 8 cm length (2.7 cm Ø) better preserved their quality during storage compared with smaller cylinders, with a shelf life of 7 days when a 4.8-kJ m¿2 UV-C dose was applied.