Prevention of microbial hazard on fresh‐cut lettuce through adoption of food safety and hygienic practices by lettuce farmers

Abstract

Lettuce is consumed raw in salads and is susceptible to microbial contamination through environment, agricultural practices, and its morphology, thus, a potential vehicle for food‐borne illness. This study investigated the effect of adoption of food safety and hygienic practices by lettuce farmers on the microbial safety of field sourced lettuce in Lagos State, Nigeria. Ten structured questionnaires were administered randomly to 10 lettuce farmers to assess food safety and hygienic practices (FSH). Two farmers who practice FSH and two farmers who do not practice NFSH were finally used for this study. Samples of ready‐to‐harvest lettuce, manure applied, and irrigation water were obtained for a period of five months (August – December 2013) and analyzed for total plate count (TPC), total coliform count (TCC), Escherichia coli, Listeria spp., Salmonella spp., and Shigella spp. counts. Result of microbial analyses of lettuce samples was compared with international microbiological specification for ready‐to‐eat foods. Results showed that the range of TPC on lettuce was 6.00 to 8.11 LogCFU/g from FSH farms and TPC of lettuce samples from NFSH farms ranged from 6.66 to 13.64 LogCFU/g. 1.49 to 4.85LogCFU/g were TCC ranges from lettuce samples obtained from FSH farms while NFSH farms had TCC ranging between 3.95 and 10.86 LogCFU/g, respectively. The range of isolated pathogen count on lettuce from FSH and NFSH farms exceeded the international safety standard; there was a significant difference in the microbial count of lettuce from FSH farms and NFSH farms. This study concludes that the lettuce samples obtained did not pass the international microbial safety standards. FSH compliance is a major determinant of the microbial safety of lettuce. Hence, the institution of FSH on farm to improve microbial safety of lettuce produced for public consumption is emphasized.

Microbiological and Nutritional Analysis of Lettuce Crops Grown on the International Space Station

“…Bacterial and fungal counts on fresh plant material are not necessarily an indication of the food quality and microbiological safety of the item and vary depending on the type of plant (Leff and Fierer, 2013;Qadri et al, 2015). Studies show that leafy greens grown in the field or greenhouse have a range of approximately 4-8 log 10 CFU bacterial counts per gram of sample while yeast and mold counts on lettuce are reported in the range of 2-5 log 10 (Valentin-Bon and Jacobson, 2008;Rastogi et al, 2012;Jackson et al, 2013;Holvoet et al, 2015;Wood et al, 2015;Hagenmair and Baker, 2016;Oyinlola et al, 2017;Fröhling et al, 2018;Zhang et al, 2018). The microbial counts on lettuce leaves grown on ISS in VEG-01A, B and both harvests from VEG-03A were relatively low on average when compared to farm or market produce counts of similar type.…”

“…The bacterial counts on lettuce leaves grown on ISS in VEG-01A, B and both harvests from VEG-03A were relatively low on average, 3.53, 4.86, 2.89, and 2.14 log 10 CFU/g respectively (Figure 2), when compared to farm or market produce counts of similar type (Valentin-Bon and Jacobson, 2008;Rastogi et al, 2012;Jackson et al, 2013;Holvoet et al, 2015;Wood et al, 2015;Hagenmair and Baker, 2016;Oyinlola et al, 2017;Fröhling et al, 2018;Zhang et al, 2018). Fungal counts on Veggie grown lettuce ranging from 2.3 to 4.3 log 10 CFU/g were within the range of yeast and mold counts on lettuce reported in the literature (Figure 3) (Oliveira et al, 2010).…”

“…Plant-growth conditions, the surrounding environment, mineral nutrition, and plant species can all influence the microbial populations living on plant surfaces (Lindow and Brandl, 2003). A variety of microorganisms can be found on fresh produce, most as part of the normal flora of the plant with no adverse effect on humans if consumed (Heaton and Jones, 2008;Leff and Fierer, 2013;Oyinlola et al, 2017).…”

Probiotic activities of Rhizobium laguerreae on growth and quality of spinach

“…The pathogenic bacteria associated with fresh vegetables may come from irrigation water and from the manure or compost used to fertilize crops. This means that on-farm food safety practices are essential for preventing the microbial hazards linked to the consumption of raw food products 4 . These safety practices have been defined taking into account not only health safety and food quality, but also the environmental sustainability of agriculture 4 .…”

Analysis of the Microbiota on Lettuce (Lactuca sativa L.) Cultivated in South Korea to Identify Foodborne Pathogens

“…Nowadays, South Korea produces more than 200,000 tons of lettuce in over 8,000 ha of land, and production and consumption are steadily rising [1]. Lettuce is not only rich in vitamins and potassium, but also contains dietary fiber and minerals, making it a very nutritious food source [2]. However, the consumption of raw lettuce has been closely linked to food poisoning.…”