Grape Preservation by Plasma Synthesized NO Fumigation

In this paper, the high concentrations of NO are produced under different gas flow speeds and enhanced by coconut shell charcoal. Further, thus were used to fumigation fresh grapes (shine muscat). With the applied voltage and frequency loaded on the discharge reactor are controlled at 17.0 kV and 8.0 kHz. When the gas flow speeds increased from 0.4 to 2.0 m/s, the concentration ratios of NO and total nitrogen oxides (NO/NOx) have presented firstly increased and then decreased, reaching a maximum value of 61% at 1.2 m/s. In order to obtain higher concentrations of NO, fully contacting the discharged gas with 200 ℃ coconut shell charcoal, which can reduce O3 and NO2 by 85%. Stored at 23 ℃, grapes were fumigated with different concentrations of NO. The experimental results indicate that as the concentrations of NO increased, the respiration rates of grapes are inhibited. Further, the concentrations of CO2 and the weight loss rate decrease. Simultaneously, the decline in the soluble solids of grapes was inhibited. Compared to unprocessed group, the treated grapes with the concentration of NO for 600 ppm showed an overall decrease of about 20% in respiratory rate and a decrease in weight loss rate from 2.8 to 1.9% on the 15th day.