Effect of UV-C irradiation combined with a sodium alginate edible coating on postharvest quality and antioxidant potential of sour guava (Psidium friedrichsthalianum Nied.)

Sour guava is a promising fruit due to its nutritional value and phytochemical richness in the fresh state. However, reports on the postharvest behavior of this fruit are very limited. Therefore, the aim of this research was to evaluate the effect of emerging technologies on the quality attributes and antioxidant potential of sour guava. A completely randomized design with two factors (treatment type and storage time) was employed. Fruits were divided into three lots according to the treatment applied: control (C), UV-C irradiation for 5 minutes (UV), and a combined treatment consisting of UV-C irradiation for 5 minutes followed by the application of a 2 % sodium alginate edible coating (UV+EC). After treatment, the fruits were stored for 21 days at 8 °C and 70 % relative humidity. Physicochemical parameters (pH, total soluble solids, titratable acidity, firmness, and weight loss), color attributes (L*, a*, and b*), and antioxidant activity (total phenolic content and antioxidant capacity determined by DPPH, ABTS, and FRAP assays) were evaluated on days 0, 7, 14, and 21. A two-way ANOVA followed by a Tukey’s post hoc test was conducted to assess the effects of treatment type and storage time on physicochemical parameters, color attributes, and antioxidant activity (p < 0.05). Results showed that UV+EC treatment effectively delayed ripening and helped preserve both surface color and antioxidant capacity during storage, whereas the UV treatment alone only increased antioxidant activity up to approximately day 14 of storage. Further research is required to evaluate sensory acceptance and to conduct a complete metabolomic characterization.