The role of the consumer in the reduction of Listeria monocytogenes in lettuces by washing at home

Abstract

Lettuce is highly appreciated for its nutritional properties; however microbial contamination through the food chain and its raw consumption may jeopardize these known benefits to the diet. The objective of this study was to determine the role of the consumer at the stage of washing at home, in relation to the probability of illness due to the presence of Listeria monocytogenes in lettuce. Survival curves of L. monocytogenes after washing (dipping with and without addition of bleach, and washing under a running tap) were studied. A mathematical model for each washing method was calculated by fitting experimental data. The obtained models were used to estimate the probability of illness after washing at home. Results show that although consumers can only deal with low loads of L. monocytogenes, their role is essential to reduce the normal contamination level of lettuces and ensure their safety.

Evaluation of risk impact of consumers' behaviour in terms of exposure to Listeria monocytogenes in lettuce

“…The reduction models applied to estimate the reduction of L. monocytogenes according to the type of washing were suggested by Doménech et al . (). Equation shows the model proposed for estimating the reduction after washing under running tap water and eqn after dipping lettuces for different times and doses of bleach.…”

“…Taking into account that the consumption of lettuce in Spain is around 7.56 kg per person per year and the size of each serving is 50 g (MAPA, ), 151.2 servings per person per year are consumed. That means a probability of listeriosis per serving of 1.32E‐8 (Doménech et al ., ).…”

“…However, <1% of the samples contained more than 100 CFU g −1 (EFSA, ). In this paper, L. monocytogenes at retail was estimated based on combined data in the literature (Abadias et al ., ; Doménech et al ., , ). As a result, a lognormal distribution with a minimum value of 0, mean of 1.09 and a maximum of 4 CFU g −1 represented the probabilistic density function of L. monocytogenes at retail, (eqn ).…”

Combined effect of ultrasound and essential oils to reduce Listeria monocytogenes on fresh produce

“…Higher reductions were obtained with Food Science and Technology International 0(0) cinnamon and lemon oil applications in the present study. Dome´nech et al (2013) applied sodium hypochlorite solutions with various concentrations (4, 8 and 40 ppm) and treatment times (5, 15 and 30 min) to remove L. monocytogenes from fresh produce. The highest microbial reduction was observed with the 8 ppm chlorine treatment for 30 min (2.04 AE 0.2 log cfu g À1 ), whereas the tap water (with 0.7 ppm chlorine) treatment resulted in an approximately 1.1 log cfu g À1 reduction.…”

Análise da expressão gênica, formação de biofilmes e adesão/invasão a célula Caco-2 por Listeria monocytogenes em diferentes condições encontradas no trato gastrintestinal, em alimentos e em presença de bacteriocinas

“…Ding et al (2012) realizaram um estudo modelo para analisar o risco de contaminação de hortaliças por L. monocytogenes e concluiram que havia um alto potencial de incidência de listeriose nas condições estudadas (11,9-17,4 casos por milhão pessoas). Doménech et al (2013) (CRUZ et al, 2008, HOFER et al, 1998 FARBER, 1996), hortaliças (FRÖDER et al, 2007, OLIVEIRA et al, 2010, peixe surubim (ALVES et al, 2005).…”