Packaging effect on the quality of refrigerated apple cubes in systems containing oranges juice, organic acids and preservatives

ANDRÉS, SILVINA CECILIA; GIANNUZZI, LEDA; ZARITZKY, NOEMÍ E.

Murcia, España

Conferencia; IIF-IIR Conference, Improving postharvest technologies of fruits, vegetables and ornamentals.; 2000

International Institute of refrigeration (IIR)

Ready-to-use fruits and vegetables deteriorate during storage by physiological aging, discoloration at the cut surfaces and microbial spoilage. Discoloration involves the enzymatic polymerisation of phenolic compounds; it is retarded by low temperaturestorage, low levels of oxygen ans the addition of antioxidants. The objetive of the present work was to analyzed changes in surface color, instrumental texture and microbial growth (moulds and yeasts) in apple cubes (Red Delicious and Granny Smith) immersed in fresh unpasteurized orange juice (with or without ascorbic and citric acids) with the addition of preservatives (potassium sorbate and benzoate, 250-1000 ppm) during refrigerated storage at 10°C in packaging plastic films with different gaseous permeabilities (polyethylene and EVA-SARAN-EVA). Coliforms and sulfite reducing bacteria were also tested to analyze the sanitary conditions of the product. Microbial growth was modelled using linear and Gompertz equation. Benzoate was discarded as preservative, because it affected surface color of the product. Results showed that for both apple varieties, the use of low gaseous permeability films and the simultaneous application of potassium sorbate improved refrigerated storage life. In all cases the absence of pathogenic microorganisms was verified.