Efficacy of benzyl isothiocyanate for controlling Salmonella on alfalfa seeds and sprouts

Authors: YIN, HSIN-BAI - Orise Fellow; Boomer, Ashley; CHEN, CHI-HUNG - University Of Maryland; Patel, Jitu

Submitted to: International Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2020
Publication Date: 1/9/2020
Citation: Yin, H., Boomer, A.M., Chen, C., Patel, J.R. 2020. Efficacy of benzyl isothiocyanate for controlling Salmonella on alfalfa seeds and sprouts. International Journal of Food Science and Technology. https://doi.org/10.1111/ijfs.14520.
DOI: https://doi.org/10.1111/ijfs.14520

Interpretive Summary: Consumption of sprouts has increased in the past decade due to its health benefits. Alfalfa sprouts are one of the most common sprouts consumed in the United States due to its availability and nutritional values. However, sprouts have been identified as a vehicle for foodborne illnesses resulting in 48 outbreaks and 2,474 cases in the United States. The FDA recommends treatment of seeds with 20,000 ppm chlorine which often fails to kill bacterial pathogens due to complex seed structure. We used benzyl isothiocyanate (BIT), a compound found in cruciferous vegetables, for controlling Salmonella on alfalfa seeds and sprouts . Alfalfa seeds inoculated with 5 individual Salmonella serovars were treated with BIT (0.5%-2%) or chlorine (20,000 ppm). Treated seeds were sprouted in seed sprouters. BIT at 1.5% and 2% concentrations significantly reduced populations S. Typhimurium and S. Braenderup on seeds to a level comparable to the chlorine-treated seeds. Salmonella populations recovered from the sprouts germinated from 1.5 or 2% BIT-treated seeds were significantly lower than the chlorine-treated seeds at both inoculum levels. The results are helpful to sprout growers in controlling Salmonella on alfalfa seeds.

Technical Abstract: The efficacy of benzyl isothiocyanate (BIT), a compound found in cruciferous vegetables, for controlling Salmonella on alfalfa seeds and sprouts was investigated. Alfalfa seeds were inoculated by individual Salmonella enterica serotypes Newport, Typhimurium, Tennessee, Montevideo, or Braenderup at two inoculation levels of 3 or 5 log CFU g-1, followed by treatment with BIT (0.5%-2%) or chlorine (20,000 ppm). Treated seeds were sprouted in seed sprouters. Surviving Salmonella populations on the seeds and sprouts were determined. At both inoculum levels, 1.5% and 2% of BIT significantly reduced populations S. Typhimurium and S. Braenderup on seeds to a level comparable to the chlorine-treated seeds. Salmonella populations recovered from the sprouts germinated from 1.5 or 2% BIT-treated seeds were significantly lower than the control and chlorine-treated seeds at both inoculum levels (P<0.05). Results of the study indicate that BIT can be used to control Salmonella contamination on alfalfa seeds and subsequent sprouting process.