No abstract

The effects of packaging and storage at 3C in a refngerated case on quality changes of minimally processed cabbage were studied. Shredded cabbage samples were packaged in three f o m : bags of monooriented polypropylene film (OPP bags) and polyethylene trays overwrapped with a multilayer polyolefin (RD106-PE tray) or with a plasticized PVC film (PVC-PE tray). A11 types of package effectively controlled the weight loss. The modified atmosphere in PVCand RD106-PE trays did not change more than 3 % as compared with normal atmosphere levels. However, in OPP bags, 0, reached 2% and CO, increased to approximately 13% after 3 days. The microbiological quality during the storage period for all types of packaging was satisfactory. OPP samples were significantly better ( p < 0.05) in general appearance, wilting and browning but developed an off-odor. No off-odor was detected in samples packaged in PVC and RD106-PE trays. Shelf life for the three packaging f o m was estimated.

Shredded lettuce was packaged in sealed bags of monoorientedpolypropylene (OPP) film and also in polyethylene (PE) trays overwrapped with a rnultilayer polyolejn (RD1 06) or plasticizedpolyvirryl chloride (P VC) film; and stored at 4C in a refiigerated case during 8 days. Chemical treatment by dipping in a 0.3% ascorbic acid /0.3% citric acid solution did not significantly affect changes in microbial populations or visual sensory attributes. Type of package was not a signrfcant factor for microorganism populations, but was signijkant @

Shredded, washed and centrifuged cabbage was packaged in monooriented polypropylene (OPP) bags, inoculated with Salmonella hadar and stored 10 days at 4ЊC, 12ЊC and 20ЊC. Microbiological, appearance, odor and headspace gas analysis were evaluated throughout storage. S. hadar and mesophilic aerobic and psychrotrophic microorganism growth was affected by storage time and temperature. S. hadar counts were lower (pϽ0.05) at 4ЊC than at 12ЊC and 20ЊC. The score ratings for general appearance, wilting, browning and off-odor showed that all samples were commercially acceptable. Results indicated that S. hadar could survive and proliferate on minimally processed cabbage, thereby posing a potential hazard to consumers.

Washing disinfection with chlorine is widely used to reduce the initial microbiological load during the preparation of minimally processed vegetables. The effects of initial concentration of chlorine, time and the liquid volume:produce weight ratio on the reduction of Salmonella counts on inoculated spinach were evaluated using response surface methodology. Initial chlorine concentration, time and the interaction between them had a significant effect on reduction of Salmonella populations. However, the liquid volume:produce weight ratio did not have significant effects. The highest Salmonella reduction was around 1·2–1·4 log at 125 ppm during 8 min regardless of the water:produce ratio. According to the results, chlorination reduced Salmonella hadar population, but the complete elimination from the produce was not achieved.