Enhancement of phenolic compounds in vanilla curing with the application of UVC light, microwaves and ultrasound

Short-wave ultraviolet light at 254 nm (UVC light) was evaluated at different doses (0.9, 2.16, 4.50 and 7.16 J/m²) to increase phenolic compounds and analyze its effect on the native microbial flora present on vanilla (Vanilla planifolia) beans (VB). Subsequently, microwave and ultrasound treatments were applied, individually or in combination, at different powers levels (1100 and 600 W) and amplitudes (50 and 90%) during the curing process. In the UVC light treatment, a dose 2.16 J/m² was the optimal, resulting in a 74% increases in total phenolic compounds (TPC) in VB compared to the control. During the curing process of the irradiated VB, the combination of microwave (600 W) and ultrasound (50% amplitude) resulted in 37.909 ± 0.52 mg GAE/g d.m. of TPC, while non-irradiated pods showed 29.869 ± 0.54 mg GAE/g d.m. at 50 days. This methodology offers several advantages, such as eliminating the need for tedious handling and skilled labor.