Quality changes in packaged salad products during storage

The quality of four types of packaged salad products (retail and foodservice Garden salad, Caesar salad, and European salad) manufactured by five major processors and stored at 5 degrees C for 20 days was assessed. The O-2 and CO2 concentrations in the bags were 0.2-1.5% and 5-30%, respectively. Overall visual quality scores were generally at or above the minimum acceptable value for salability at the ''Best if Used by Date'' (12-16 days after processing). Product sensory attributes (visual, flavor and textural properties) determined by a trained judge and a sensory panel significantly correlated for most of the parameters. Off-odors developed in the packages and their scores significantly correlated with ethanol and acetaldehyde concentrations in the lettuce tissue. Sugar content decreased 12% (iceberg) to 20% (romaine) from days 0 to 15. Total aerobic microbial load increased by an average of 2.5-3 log units over 20 days.