Effect of application of ozone at low-pressure on the technological properties, phenolic compounds, and antioxidant capacity of common beans during storage

The objective of this study was to assess the effects of low-pressure ozone treatment on the technological quality, phenolic compounds, and antioxidant capacity of common beans (Phaseolus vulgaris L.) during storage. Samples of 5.0 kg of dry beans were exposed to ozone in a hypobaric chamber with an internal volume of 70 L. Ozone was injected until the internal chamber pressure reached 100000 Pa, with an inlet concentration of 61.37 mg L⁻¹ and flow rate of 1.0 L min⁻¹. Ten cycles of ozone injection were adopted. Oxygen was used in control treatment. The effect of the treatments on the grain quality was assessed over storage for 180 days. Ozone did not affect the percentage composition of the dry beans, which exhibited 18.76% of protein, 11.66% of moisture content, 3.44% of minerals, 1.32% of lipids, and 64.51% of carbohydrates. A significant difference (p < 0.05) between the treatments and the control was noticed in total titratable acidity. The luminosity (L∗) and hue (h∗) of the grains were not altered by ozonation. Ozone had a significant effect (p < 0.05) on the phenolic content of the dry beans but no significant effect (p > 0.05) on their antioxidant capacity. The phenolic compounds content and antioxidant capacity decreased over storage in all treatments. Ozone application at low pressures proved a promising technology for controlling insect pests and promoting fungal decontamination without altering dry bean quality throughout storage.