Efficacy of low O2 and high CO2 atmospheres in maintaining the postharvest quality of saskatoon fruit (Amelanchier alnifolia Nutt.)

Changes in fruit quality of saskatoon (cvs. Pembina, Smoky, Northline, and Thiessen) stored under three O2 levels (2, 10, and 21%) factorially combined with two CO2 concentrations (0.035% and 5%) were assessed during 56 d of storage at 0.5 degrees C. The 5% CO2 atmosphere combined with 21 or 10% O2 was most effective at minimizing losses in fruit soluble solids, anthocyanins, firmness, and fresh weight. Fungal colonization of fruit after 8 wk of storage was eliminated in 5% CO2 at all O2 concentrations. Storage of fruit in 0.035% CO2 and 21 or 10% O2 resulted in the highest titratable acidity and lowest ethanol concentrations. Ethanol did not exceed 0.03% in fruit stored in any of the atmospheres. While changes in some of the quality characteristics of fruit during storage were cultivar dependent, differences among cultivars were small, and all four cultivars benefited from controlled atmosphere storage.