Application of ozone in post-harvest conservation of orange (Citrus sinensis) in La Troncal, Ecuador

Resumen

Objective: To evaluate the effect of ozone concentration and exposure time on oranges (Citrus sinensis) through experimentalmethods aimed at reducing the incidence of phytopathogenic fungi and extending their shelf life during storage. Methodology: Atotal of 384 oranges were collected and stored in a warehouse, forming 32 experimental units. A completely randomized designwas used, assessing eight treatments: six corresponding to combinations of two factors, along with two control treatments. FactorA consisted of three liquid-ozone doses (1, 2, and 3 ppm), while Factor B involved the contact time with the fruit (10 and 20minutes). Among the controls, one was a conventional treatment with sodium hypochlorite and the other an absolute control. Theevaluated variables included pH, °Brix, incidence, and severity. Data were statistically analyzed using analysis of variance(ANOVA) and Tukey's test (p < 0.05). Results: The untreated control showed the highest values for pH, incidence, and severity.Ozone doses consistently reduced these variables, particularly 1 ppm applied for 10 minutes, while the remaining treatmentspresented slight and consistent differences. Severity, as defined in the study, showed variations ranging from 11.3% to 17.7% inthe factorial treatments, 23.2% in the absolute control, and 10.9% in the conventional treatment with sodium hypochlorite.Conclusions: Ozone application decreases pH, incidence, and severity compared to the untreated control. Differences amongdoses were small, but 1 ppm for 10 minutes produced the most pronounced effects, even outperforming the conventional sodiumhypochlorite treatment. Overall, ozone improved all evaluated conditions relative to the controls.