Examinando por Autor "Shaw, Angela"

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  • Miniatura
    Ítem
    Survival of E.coli O157:H7 in Sprouts produced in home-scale hydroponic system over seven days
    (Zamorano: Escuela Agrícola Panamericana, 2023) Jovel G., Brenda F.; Luna, Ligia; Shaw, Angela
    The consumption of sprouts, particularly alfalfa sprouts, is the most consumed in the United States due to their nutritional value and perceived health benefits. However, sprouts are susceptible to microbial contamination, leading to foodborne illnesses. This study aimed to examine the survival of E. coli O157:H7, a pathogenic bacterium, in sprouts grown using home-scale hydroponic systems and to compare its growth on the surface of the jars. E. coli O157:H7, was chosen as a model microorganism. The experiment was conducted at the laboratory of The International Center for Food Industry Excellence at Texas Tech University, and bacterial culture preparation involved various steps to establish a controlled and standardized microbial population. Seeds were inoculated with E. coli O157:H7 at 4 Log CFU/g and samples were taken at periods 0, 3, 6, 12, and 24 hours, 2, 3, 4, 5, 6, 7 days for analysis. Results indicated that E. coli O157:H7 was present in both seeds/sprouts and on the surface of the jar during the entire experiment period. A Randomized Complete Block was used to evaluate the treatments. The bacterium proliferated on the sprouts, reaching concentrations of 7.64 Log CFU/g and onto the surface 5.25 Log/CFU/ml after 24 hours. The study highlighted the importance of the germination phase as a potential source of contamination in sprouts due to the favorable conditions it provides for bacterial growth. Overall, the research demonstrated the capability of E. coli O157:H7 to proliferate during the sprouting process and indicated that the hydroponic environment of sprout production might enhance bacterial growth. The findings underscore the need for stringent hygiene practices throughout the sprout production process to mitigate foodborne illness risks associated with sprout consumption.
  • Miniatura
    Ítem
    Survival of nalidixic acid strains of Salmonella Enteritidis on mung bean sprouts and surfaces produced in a home-scale hydroponic system
    (Zamorano: Escuela Agrícola Panamericana, 2023) Hernandez G., Elva A.; Shaw, Angela; Luna, Ligia
    The production of sprouts in hydroponic systems is increasing worldwide, including alfalfa, mung bean, clover, etc., which are generally consumed raw or minimally processed. Mung bean sprouts are often contaminated with pathogens during production, one of the main pathogens is Salmonella Enteritidis. The presence of Salmonella in sprouts carries a high risk during their production as disinfection methods are often ineffective in inhibiting them. This study was based on examining the survival of Salmonella Enteritidis resistant to nalidixic acid in mung bean sprouts produced in hydroponic systems for 7 days under domestic conditions to evaluate its behavior. To evaluate this, mung bean seeds were grown in jars and exposed to distilled water contaminated with Salmonella at room temperature (25 °C) and 70% relative humidity. Samples were taken from the sprouts and surface of the jars and sown on xlt4 agar with nalidixic acid to detect only Salmonella. Salmonella Enteritidis was quantified by the plate count method and was detected at levels from 4 log CFU/g to 7 log CFU/g. Salmonella Enteritidis growth was higher in the sprouts than on the surface, reaching a level of 7.35 log CFU/g, however, on the surface there was growth, but it was not significant over time, reaching levels of 6.19 log CFU/mL. It was detected that Salmonella tends to move to surfaces through the water since seed rinsing is a risk of contamination of sprouts and surfaces by Salmonella Enteritidis under domestic conditions, so it is necessary that producers implement the requirements by the food safety rule focused on the production of sprouts.