Microbiological Changes and Shelf Life of Fresh-cut Vegetables Mix in Modified Atmosphere Packs
W. Niyomlao, C. Techavuthiporn and S. Kanlayanarat
Book of Abstract. APEC Symposium on Assuring Quality and Safety of Fresh Produce, August 1-3, 2005, Bangkok, Thailand. 76 page.
2005
บทคัดย่อ
Fresh-cut Vegetables mix (VM) consisting of carrot shreds, lettuce slices and onion dices were packed in 15 mm-thick polyvinyl chloride (PVC) or 15-25 mm-thick linear low density polyethylene (LLDPE) films. VM held in the open served as control. Storage was done at 8°C with 90-95 % relative humidity. Results show that without film packaging, the VM kept in storage for only 1 day due to rapid browning. However, microbial counts were lower and Salmonella sp. was not detected as compared to film-packed VM. Microbial population in film-packed VM generally increasing with increasing duration of storage and the increase was most rapid in 25 mm-thick LLDPE and least in 15 mm-thick PVC. Mold growth was higher than that of yeast. Among microorganisms as potential food safe hazard, higher Salmonella population was noted than that of E. coli. Plate counts of mold, yeast, E. coli and Salmonella sp. increased from about 0.5, 1.25, 0.42 and 0.5 log CFU/g at day 0 to about 2.8-3.5, 2.0-2.3, 0.7-0.9 and 3.2-3.5 log CFU/g at the end of storage. VM held in 25 mm-thick LLDPE films had a shelf life of 3 days, i.e. 2 days longer than that without film pack. Shelf life further increased by one day more in 15 mm-thick LLDPE or PVC films. Browning and decay limited shelf life of film-packed VM.