IMPROVEMENTS IN CANNED LOWBUSH BLUEBERRY QUALITY

Individually quick frozen lowbush (wild) blueberries (Vaccinium angust ifolium) were canned with 0, 1500, or 3000 ppm calcium from chloride o r lactate salts and 0, 0.25, or 0.50% citric acid in water. Physical a nd pH changes were measured at 0, 6, and 12 mo, and sensory evaluation s were made at 3 and 9 mo post-canning. Calcium increased firmness and berry calcium content. Calcium chloride and citric acid reduced pH an d increased hue angle and off-flavor; calcium lactate increased draine d weight and pH but reduced hue. Response surface methodology predicte d changes in calcium lactate-treated berries, but not CaCl2-treated be rries. Optimal conditions were 1200-1800 ppm calcium lactate at 3-6 mo storage.