EFFECTS OF MODIFIED ATMOSPHERE IMPOSED WITH THE PALLIFLEX SYSTEM ON POSTHARVEST FRUIT QUALITY OF 'RED GLOBE' TABLE GRAPES

The use of Pallifex storage system is getting popular and suitable for short and long term storage under CA and ULO conditions for many fruits and vegetables. In this system, instead of whole cold room, a desired atmosphere is created in individual pallets.
In this research, the effects of different atmosphere compositions on postharvest fruit quality of ‘Red Globe’ grapes were investigated. For this purpose, grapes were stored for 90 days at 0°C temperature with 95% relative humidity in five different atmosphere compositions. These compositions were: 21% O₂ + 0.03% CO₂ (Control-PL-1), 2% O₂ + 0.03% CO₂ (PL-2), 2% O₂ + 2.5% CO₂ (PL-3), 2% O₂ + 5% CO₂ (PL-4) and 1% O₂ + 2.5% CO₂ (PL-5). Fruit samples were taken from different storage conditions at certain intervals and physical and chemical parameters such as weight loss, flesh firmness, total soluble solids content, titratable acidity, skin color (chroma, hue), berry shatter, rachis browning and percentage of fungal decay were determined and recorded on the grapes.
The experimental results showed that the lowest weight loss was obtained on the grapes stored in PL-4 composition. The berries stored in PL-4 had higher fruit firmness and total soluble solids content. In terms of titratable acidity berries stored in PL-1, PL-2 and PL-3 had higher amount of titratable acidity at the end of 90 days at 0°C. Chroma values and hue angle of the fruit showed a decrease during the entire storage period in all atmosphere compositions. The most effective atmosphere composition for controlling rachis browning was PL-5 and decay was PL-4.