EXTENSION OF SHELF-LIFE OF BAKERY PRODUCTS PACKED UNDER MODIFIED ATMOSPHERE

The effectiveness of modified atmosphere packaging in extending the shelf-life of three bakery products with different water activities (0.78, 0.82, 0.90) was checked against spoilage mould species isolated from these products. The ability of two strains of Staphylococcus aureus to grow and produce enterotoxins A and B in the product with a(w) = 0.90 was also examined. M.A. (30% CO2-70% N2) packaging significantly extended the shelf-life of all three products tested. Packaging film choice was found to depend on the a(w)-value of the product to be packaged: an O2 medium-barrier film was sufficient for the product with a(w) = 0.78, while an O2 high-barrier film was required for the product with a(w) = 0.90. In any case introducing expanded plastic dishes under the product in the package was absolutely to be avoided. The above mentioned modified atmosphere did not inhibit the S. aureus growth and enterotoxins A and B production.