|Authors: ||N. Admane, G. Altieri, F. Genovese, G.C. Di Renzo, V. Verrastro, L. Tarricone, A. Ippolito|
|Keywords: ||quality, SO2 alternative, high carbon dioxide, ozone, modified atmosphere packaging|
The increased demand of fresh organic table grapes with perfect appearance and good sensory attributes is very challenging due to the restriction of sulphur dioxide (SO2) use on certified organic produce.
In this context and in order to reach overseas promising markets, the aim of this experimental trial was to maintain the quality of organic table grapes for medium and long term storage by using alternative methods to SO2 application that can fit together with organic productions.
Clusters of the organic late-season cultivar ‘Scarlotta Seedless®’ brand were pretreated with different concentrations of ozone (O3) varying from 5 to 20 ppm and carbon dioxide (CO2) at 50 and 70%, and compared to untreated control.
All the processed samples were packed in thermo-sealed ALPAK commercial bags with 2% O2, 5% CO2, 93% N2 modified atmosphere packaging (MAP) and stored at 0°C for 45 days.
The main fruit quality parameters, weight loss, grey mold incidence, berry firmness and color, total soluble solids content (TSS), pH, titratable acidity and sensory qualities, were measured on cluster samples immediately at harvest and after 15, 30 and 45 days under simulated shipping conditions.
After 45 days, there were no signiﬁcant differences of physical and chemical quality parameters between pretreated samples and control.
Nevertheless, the sample pretreated with O3 at 20 ppm minimized water loss compared to the samples pretreated with massive CO2 concentration and controlled berry decay due to Botrytis infection.
Color Index for Red Grapes (CIRG) values were inversely correlated with Chroma, particularly higher in the control and lower in the sample treated with O3 at 20 ppm.
The results indicated that pretreatments did not have any significant effect on grapes quality, and highlighted the efficiency of both film packaging and MAP in postharvest control of decay and quality loss of organic table grapes stored for more than 45 days.
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