EXTENDING SHELF LIFE OF COMMERCIAL VACUUM PACKAGED FRANKFURTERS BY ADDITION OF ORGANIC ACID SALTS IN THE FORMULATION

摘要

Inclusion of sodium lactate (SL), sodium acetate (SA) and sodium diacetate (SDA) in cured meat formulations is an effective antilisterial hurdle in vacuum packaged RTE meats. This study evaluated whether these organic acid salts may also extend shelf life of cooked meat products by controlling growth of the natural lactic acid bacteria (LAB) spoilage flora. Frankfurters (12 cm length, 24 mm diameter) were formulated in a commercial meat plant, with 1.8% (3% of a 60% w/w commercial product) SL, or with 1.8% SL plus 0.25% SA or 0.25% SDA. Frankfurters without salts served as controls (CN). Peeled frankfurters (pH 6.1-6.4) were vacuum packaged (8 links/pack), stored at 4 or 12°C, and analyzed microbiologlcally, for pH and sensory evaluation at 0, 7,15, 30, 45, 60, and 90 days of storage. Initial LAB contamination of frankfurters ranged from 2.4 to 2.7 log cfu/g between treatments. During storage, LAB growth was more pronounced in the order CN > SL+SA > SL > SL+SDA, while was faster at 12 than at 4°C, irrespective of treatment. Specifically, as compared with the CN, SL singly and SL+SDA delayed (P < 0.05) LAB growth by 2.3 and 5.3 logs, and 1.0 and 3.5 logs, after 45 and 60 days of storage at 4°C, whereas SL+SA was not effective after day 7. After 90 days at 4°C, LAB growth was retarded (P < 0.05) below 7 log cfu/g in frankfurters with SL+SDA only; all other treatments had LAB counts of 7.8-8.4 log cfu/g. Conversely, at 12°C, differences in LAB counts were not so great since SL and SL+SDA could delay (P < 0.05) LAB growth for only 7 and 15 days, respectively. The final (day-90) pH values of the CN, SL+SA, SL, and SL+SDA frankfurters were 5.0, 5.6, 5.3 and 5.5 at 12°C, and 5.6, 5.9, 6.2 and 6.1 at 4°C, respectively. In-package gas and slime formation and off odors at opening decreased in the order SL+SDA (good at 90 days)