Application of Ultraviolet Radiation for increasing the content of antioxidant compounds of fresh-cut peaches.

RAGUSA, M.; ZARO, M.J.; POLENTA, G.; BAUDAGNA, S.; DENOYA, G.

Sorrento

Workshop; IFT-EFFoST International Nonthermal Processing Workshop and Short course.; 2018

New applications of non-thermal technologies include their use as an abiotic factor, able to exert an exogenous physiological stress on fruits and vegetables and concomitantly induce the synthesis of secondary metabolites with high antioxidant capacity. This innovative application requires process conditions milder than the ones used for non-thermal preservation and consequently, lower energy expenditure. This work aimed to explore the ultraviolet radiation (UV-C) applied at levels able to increase the content of antioxidant compounds in fresh-cut peaches, but preventing the deterioration of the general quality of the product. Cylinders of peaches cv. Rubyprince were subjected to different UV-C radiation doses (1, 5, 10 KJ/m2) and were evaluated during refrigerated (4°C) storage (1, 4, 8 days). To evaluate the effect on the content of antioxidant compounds after the treatments, total phenols and antioxidant capacity, with different methods, were determined over the samples. In addition, the effect of the treatment on the textural and chromatic parameters of the product was evaluated by the Textural Profile Analysis and the CIEL*a*b system, respectively. The 1KJ/m2 dose was the one that caused the major effects on the evaluated parameters. Although the total phenol content was not augmented significantly (p>0.05) after the treatments, the application of 1KJ/m2 on the cylinders increased (p<0.05) the antioxidant capacity of the fresh-cut fruit at day 1. However, this significant increase was no longer observed during the refrigerated storage. Some textural parameters (hardness, chewiness) were also higher (p<0.05) after the application of this dose, remaining high during storage. The chromatic parameters were not affected (p>0.05) by the treatments. In conclusion, the application of 1KJ/m2 of UV-C on fresh-cut peaches increased the antioxidant capacity of the fruit without negative effects over the textural and chromatic parameters. However, future research must be carried out for the preservation of the antioxidant capacity of the fresh-cut peaches during storage.