Beef patties containing natural antioxidants-cayenne hot pepper, red sweet pepper, lycopene-rich tomato pulp (LRTP) and extract of tomato rich in lycopene (Lyc-O-Mat(TM))-and packaged in modified atmosphere were evaluated for storage stability at 2 VC by measuring CIE a* values, surface metmyoglobin, TBARS, psychrotrophic bacteria counts and, sensory off-odour and discolouration. Results demonstrated that the addition of ground peppers (both sweet and hot) to beef patties delayed and inhibited very significantly (p < 0.05) the oxidation of both myoglobin and lipid as well as the growth of psychrotrophic bacteria. As a consequence, and according to instrumental and sensory results of meat colour and odour, the shelf life of beef patties was extended from about 4 to about 16 days. Capsaicinoid-rich cayenne hot pepper exerted a more intense antioxidative effect than capsaicinoid-free red sweet pepper. The addition of lycopene-enriched tomato products (LOM and LRTP) was not as effective as treatment with peppers, although they exerted a significant (P < 0.05) antioxidative effect too, depending on the lycopene concentration. These tomato products delayed meat deterioration to a varying extent, so that the shelf life of treated beef patties ranged between 8 and 12 days. (C) 2003 Society of Chemical Industry.
