Microbiological quality of fresh-cut cabbage treated with disinfectant and stored in active MAP
Y. Murakami, S.K. Wendakoon, R. Okumura and H. Izumi
Book of abstracts, APS2010 & SEAsia2010 & GMS2010, August 2-4, 2010, Radisson Hotel, Bangkok, Thailand
2010
บทคัดย่อ
Microbiological and organoleptic quality of fresh-cut cabbage was evaluated during storage in active modified atmosphere packaging (MAP) at 10°C. The samples were initially treated with tap water or 0.05% calcined calcium agent (91% of calcium) followed by ozonated water (5 ppm of ozone) and subsequently packaged, which was flushed with air or 10% CO2.When fresh-cut cabbage was stored in MAP flushed with air or 10 % CO2 for 7 days at 10°C, CO2 accumulated to 13-15% and O2 depleted to 2-4% in the packages. The CO2 concentration approached equilibrium after 4 days storage in packages flushed with air, while the equilibrium was attained immediately in packages flushed with CO2. The treatment with calcined calcium agent followed by ozonated water was effective in reducing counts of mesophiles, coliforms, and psychrotrophes by 1-2 logs relative to water-dipped control on initial day. The count of lactic acid bacteria on all samples was below the detection level (2.4 log CFU/g). A residual effect of the disinfectant treatment occurred with the microbes except for lactic acid bacteria for the first 3 days of storage. The packages flushed with 10% CO2 was effective in reducing growth of psychrotrophs by 0.8 to 1.1 logs as compared to those flushed with air throughout 7 days of storage. Bacteria isolated from fresh-cut cabbage were phytopathogenic and soilborne organisms such as genera Acinetobacter, Enterobacter, Pseudomonas, and Stenotrophomonas. The diversity of bacterial flora in the treated samples was much less in packages with 10% CO2 than those with air. Neither treatment of disinfectant or 10% CO2 flush affected organoleptic quality including browning, water-soaked appearance, and pitting of freshcut cabbage. These results indicate that when fresh cut-cabbage was treated with calcined calcium agent with ozonated water and then stored in active MAP of 10% CO2, bacterial counts and the number of bacterial strains detected on cabbage were controlled during storage.