S23 - Session O8 - Effectiveness of plastic pallet covers to shift the marketing period of fresh wild blueberries

Authors: Arturo Duarte-Sierra *, Deepak Kumar Jha

The efficacy of three different types of plastic pallet covers was determined in relation to the preservation of quality parameters of wild blueberries ( Vaccinium angustifolium Ait.) after 24 days of storage. Blueberries were harvested in farms near Normandin, Quebec, and pre-cooled with forced air at 6 °C in a commercial packing house located close to the fields. The fruit were then distributed on pallets of approximately 50 kg/pallet. Five factors were use on the experimental design: 1) type of plastic cover (no cover, polyethylene, PrimePro and LifeSpan); 2) temperature (0 °C and 4 °C); 3) type of fruit (unsorted or sorted); 4) CO 2 injection (0 %, 10 %, 20 %); and 5) addition of a SO 2 -generating patch (not present, or present). A total of 18 pallets were used, of which 8 were stored at 4 °C/89 % RH in a cold room, and 10 at 0 °C/81 % RH inside a reefer. Although the relative humidity inside both spaces was low, the covered pallets at both temperatures remained above 95 % RH throughout storage. As a result, it was found that weight loss on uncovered pallets was significantly (p=0.0002) higher compared to the covered pallets stored at either 0 °C or 4 °C. Regardless of temperature, berries exposed to CO 2 (10 % and 20 %) showed a significantly (p=0.02914) more intense blue-purple color (°hue) compared to non-exposed berries. Yet the size of fruit was not affected by either temperature or type of cover. Carbon dioxide addition also had a significant (p=0.02384) influence on fruit soluble solids content, especially in fruit exposed to 20 %. Overall, the visual quality of berries stored at 0 °C using the plastic covers was better than those uncovered and/or stored at 4 °C.