Assessing the Influence of Proportions Between Amount of Vegetables Immersed and Volume of Water To Inactivate Salmonella in Minimally Processed Lettuce and Carrot, Mimicking Disinfection Practices Employed by Brazilian Processing Plants

Abstract

ResumoThe proportion between amount of vegetables immersed and volume of water used during the disinfection step of minimally processed vegetables (MPV) is a factor that can affect the efficacy of disinfection process and consequently the quality and safety of the final product. This study aimed at assessing the influence of proportion between amount of vegetables immersed and volume of water on inactivation of Salmonella during the disinfection step of minimally processed lettuce and carrot, mimicking practices employed by MPV processing plants in Sao Paulo, Brazil. Minimally processed lettuce or carrot (1 Kg) was spiked with Salmonella (6 log CFU/mL) through immersion in experimentally contaminated water (4 L at 25ºC) for 30 min, and then transferred to recipients containing water with organic chlorine (250 mg/L at 25ºC and pH 7.0). The volumes of water tested to disinfect 1 Kg of lettuce were 8, 16, 23 and 28 L, while for disinfection of 1 Kg of carrot were tested 1, 6 and 12 L of water. These values corresponded to the proportions employed by Brazilian processing plants during disinfection step of MPV. The disinfection of minimally processed lettuce caused a reduction of 1.8, 1.9, 1.9 and 2.0 log CFU/g 363