Evolution of respiration rate, internal CO₂ or O₂ and resistance to gas diffusion of anaerobic exposed and waxed 'Miho' satsuma fruits during market life

Abstract

'Miho' satsumas received an anaerobic treatment with N2 or CO2 for 24 hr at 20°C before being waxed with shellac and transferred to 20°C for 30 days, in order to measure respiration rate, internal gas evolution (CO2 and O2) and peel resistance to CO2 diffusion. Ethanol in the juice, as well as taste and appearance were also determined. Respiration rate decreased by more than half following 30 days of storage, while internal CO2 and O2 rose and decreased, respectively. Conversely, resistance to CO2 diffusion increased drastically with time in storage. Waxing significantly decreased respiration rate and doubled resistance to CO2 diffusion, while anaerobic treatments did not influence physiological parameters. Off-flavour development due to time in storage or wax application strongly affected taste of fruits. Exposition to CO2 negatively influenced fruit taste also, with respect to control and N2 exposed fruits. In general, the higher the ethanol content in the juice, the higher the off-flavour score and the lower the acceptability by panellists. The external fruit appearance declined with time in storage. Waxing or anaerobic treated fruits maintained a better freshness than control fruits. From a commercial standpoint the best result was gained with non-waxed nitrogen-treated fruits, which stored satisfactorily for 10 days