Effect of gaseous ozone on microbial inactivation and sensory of flaked red peppers

Abstract

Flaked red peppers inoculated with Escherichia coli, Bacillus cereus and B. cereus spores were exposed to gaseous ozone at 20°C and 70% relative humidity (RH). Ozone concentrations of 0.1, 0.5 and 1.0 ppm up to 360 min were used to reduce E. coli and B. cereus, whereas 1.0, 5.0, 7.0 and 9.0 ppm ozone concentrations for 360 min were used to treat B. cereus spores. When flaked red peppers were treated with 1.0 ppm ozone concentration for 360 min, B. cereus and E. coli counts were decreased by 1.5 and 2.0 log numbers, respectively. Bacillus cereus spores were reduced by 1.5 log numbers at ozone concentrations of 7.0 ppm or above for 360 min. There were slight changes in flavour, appearance and overall palatability of flaked red peppers treated with ozone between 5.0 and 9.0 ppm. Ozone concentration (1.0 ppm) for 360 min can be used to decrease E. coli and B. cereus, whereas ozone concentrations ‡5.0 ppm can be used to reduce B. cereus spores.

Evaluation of ozone efficacy on the reduction of microbial population of fresh cut lettuce (Lactuca sativa) and green bell pepper (Capsicum annuum)

“…As a result, yeasts molds and especially spore forming bacteria, require increasing ozone concentrations and longer exposure times for their inactivation. Akbas and Ozdemir (2008) examined the ozone action in flaked red peppers and observed that ozone concentrations above 5.0 ppm for 360 min must be used in order to reduce Bacillus cereus spores by 1.0e2.0 log units. Concerning the reduction kinetics of different sanitizing agents our results are also in accordance with those obtained by other investigators.…”

Cold plasma treatment for the microbiological safety of cabbage, lettuce, and dried figs

“…Increase in the relative humidity of the atmosphere in contact with dried fruits during storage and distribution will increase in their water activity (a w ) affecting microbiological quality and safety (Moraga et al, 2011). Figs are reportedly contaminated with Escherichia coli as well as Bacillus cereus, and damp storage conditions can cause the bacteria to grow to a level of 10 7 e10 8 CFU/g dried figs (Akbas and Ozdemir, 2008).…”

“…Dried figs, a popular dried fruit in the United States, Turkey, Greece, and Spain, are also subjected to contamination by foodborne pathogens, which occurs during harvesting, drying, storage, transportation and handling (Akbas and Ozdemir, 2008). Increase in the relative humidity of the atmosphere in contact with dried fruits during storage and distribution will increase in their water activity (a w ) affecting microbiological quality and safety (Moraga et al, 2011).…”

Inactivation of E. coli and B. subtilis spores in ozonized cassava starch

“…Comparing the results obtained for E. coli inactivation in the cassava starch and other dry products (AKBAS; OZDEMIR, 2006OZDEMIR, , 2008bEMER;OZDEMIR, 2008), it was observed that, for the other products, lower ozone concentration of 0.5-1 mg·L -1 was required to reach the same level of inactivation (i.e., 40 times smaller than that required for cassava starch). Additionally to the differences in the moisture content and water activity of these foods and cassava starch, the differences between the results obtained can be explained by different ozonized air flow and the amount of product ozonized, which interfere in the ozone available amount and also on ozone mass/ product mass ratio.…”

“…coli inactivation by ozone has been previously studied by several authors in different products including water, fruits, vegetables, meat, and dry products (MUTHUKUMARAPPAN; HALAWEISH; NAIDU, 2000; ZHAO; CRANSTON, 1995;KIM, 2001;OZDEMIR, 2006OZDEMIR, , 2008bEMER;OZDEMIR, 2008). These studies were carried out using different equipment and strains of E. coli, but, in general, it was observed that higher inactivation occurred in water or products with high moisture (MUTHUKUMARAPPAN; HALAWEISH; NAIDU, 2000).…”