EFFECT OF STORAGE CONDITIONS ON THE CHEMICAL, PHYSICAL AND SENSORY CHARACTERISTICS OF STANLEY PLUM PASTES

Stanley plums were processed into purees and then pastes by heat concentration to 25 and 30⁰ Brix. The Brix of these two pastes was increased to 40 and 45⁰, respectively, by sugar addition. Pastes were stored at 4 and 22 ± 2C in the dark for up to 24 weeks. Physical-chemical characteristics and microbiological quality were determined at 4 week intervals. Sensory evaluation was conducted at 0 and 24 weeks. Total solids, water activity, rheological properties and microbiological quality were stable during storage. Total acid, total anthocyanins, total pectin and Hunter ‘L’ and ‘a’ values decreased significantly during storage (P < 0.01). The degradation rate of total anthocyanins was much higher for pastes stored at 22C than those at 4C. Hue angle and Hunter ‘b’ values increased during storage. Sensory evaluation indicated that pastes were still acceptable after 24 weeks of storage.