Attachment of Salmonella on cantaloupe and effect of electron beam irradiation on quality and safety of sliced cantaloupe

摘要

Increase in consumption of fresh produce over the past decade has resulted in arise in incidents of foodborne outbreaks due to pathogens. Chemical sanitizers have beenextensively used in the industry for decontamination of fresh produce. However, they areineffective in certain commodities and under certain processing conditions, necessitatingthe evaluation of alternative technologies. Electron beam irradiated sliced cantaloupewere tested for 21 days of storage for total aerobic bacterial counts, texture, color andsensory parameters as a function of irradiation doses 0, 0.7 and 1.4 kGy and the washtreatments, water and 200 mg/L chlorine applied to the melons before cutting. Melonswashed only with water prior to cutting had total aerobic bacterial counts of 4.0, 2.0 and0.8 log cfu/g on day 0 at irradiation doses of 0, 0.7 and 1.4 kGy respectively. On day 0,melons washed with chlorine prior to cutting had total aerobic bacterial counts of 2.7,and 0.7 log cfu/g at irradiation doses of 0 and 0.7 kGy and below detection limit at 1.4kGy. Texture measured as compression force was lower only for cantaloupe irradiated at1.4 kGy. Irradiation did not affect objective color and descriptive attribute flavor andtexture sensory attributes of cantaloupe. Irradiation reduced Salmonella Poona by 1.1 logcfu/g at 0.7 kGy and 3.6 log cfu/g at 1.5 kGy. The D-value of S. Poona on irradiatedsliced cantaloupe was found to be 0.211 kGy. Among the spoilage organisms, lactic acidbacteria and mold were reduced effectively by irradiation but there was no significanteffect on reduction of yeasts. Our results show that electron beam irradiation incombination with chemical sanitizers is effective in decontamination of fresh-cutproduce. Electron microscopy images provided valuable information on attachment sitesof S. Poona on cantaloupe rind. The ineffectiveness of chemical sanitizers due topossible inaccessibility to pathogens in these attachment sites provides the basis forapplication of irradiation in decontamination of fresh produce.