INACTIVATION OF LISTERIA MONOCYTOGENES, SALMONELLA ENTERITIDIS AND ESCHERICHIA COLI O157:H7 AND SHELF LIFE EXTENSION OF FRESH-CUT PEARS USING MALIC ACID AND QUALITY STABILIZING COMPOUNDS

Abstract

Inactivation of Listeria monocytogenes, Salmonella enteritidis and Escherichia coli O157:H7 and shelf life extension of fresh-cut pears using malic acid (MA) and quality stabilizing compounds (N-acetyl-L-cysteine, glutathione and calcium lactate; CGLW) were investigated. Trays of treated fresh-cut pears were wrap sealed with a thick polypropylene film (64 mm) semipermeable to water vapor, O2 and CO2, and stored at 5C for 30 days. Changes in headspace gas, firmness and color of the fresh-cut pears were also determined. Large reductions of L. monocytogenes (6.57 log10 cfu/g), S. enteritidis (6.60 log10 cfu/g) and E. coli O157:H7 (2.62 log10 cfu/g) just after processing were achieved in those fresh-cut pears dipped in CGLW + MA. Microbiological shelf life of pear pieces dipped in CGLW + MA was extended by more than 21 days in comparison with those cut pears immersed in water used as control sample. Lower consumption of O2 and production of CO2, ethylene and ethanol of fresh-cut pears dipped in CGLW + MA were also observed. In addition, the color and firmness of pear pieces in CGLW + MA were maintained by more than 21 days in comparison with control samples. In conclusion, the combination of MA with quality stabilizing compounds can be a good alternative for assuring the safety and quality of fresh-cut pears.