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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #361108
Research Project: Characterization and Mitigation of Bacterial Pathogens in the Fresh Produce Production and Processing Continuum

Location: Environmental Microbial & Food Safety Laboratory

Title: Efficacy of benzyl isothiocyanate for controlling Salmonella on alfalfa seeds

Author
item YIN, HSIN-BAI - US Department Of Agriculture (USDA)
item CHEN, CHI-HUNG - US Department Of Agriculture (USDA)
item BOOMER, ASHLEY - US Department Of Agriculture (USDA)
item Patel, Jitu

Submitted to: International Association for Food Protection
Publication Type: Abstract Only
Publication Acceptance Date: 3/19/2019
Publication Date: 7/21/2019
Citation: Yin, H., Chen, C., Boomer, A., Patel, J.R. 2019. Efficacy of benzyl isothiocyanate for controlling Salmonella on alfalfa seeds. International Association for Food Protection. 2:197.

Interpretive Summary:

Technical Abstract: Introduction: Salmonellosis outbreaks associated with consumption of alfalfa sprouts have occurred with increased frequency worldwide. It is critical to identify effective treatments for controlling Salmonella contamination on alfalfa seeds. Purpose: The purpose of this study was to investigate the efficacy of benzyl isothiocyanate (BIT), a cruciferous vegetable-derived compound, for controlling Salmonella on alfalfa seeds. Methods: Alfalfa seeds (150 g) were immersed in 300 ml of sterile deionized water containing individual Salmonella serotypes Newport, Typhimurium, and Tennessee at two inoculation levels of 4 log or 6 log CFU/ml for 2 min. After overnight air-drying, 15 g of inoculated seeds were treated with 30 ml of 0%, 0.5%, 1%, 1.5%, or 2% of BIT solutions for 30 min. Inoculated seeds with no treatment (baseline) or 20,000 ppm of total chlorine were included as controls. After treatment, seeds were stored at 25°C for 7 days, and surviving Salmonella populations were determined on days 0, 1, 5, and 7 by plating on XLT4 agars. The effect of BIT on germination of alfalfa seeds were studied using un-inoculated seeds with automated sprouting equipment. Results: The antimicrobial effects of BIT against three serotypes of Salmonella on alfalfa seeds was concentration-dependent. Anti-Salmonella activity of BIT at 1.5% and 2% level was comparable to 20,000 ppm chlorine on days 5 and 7. At the high inoculation level, ~4.5 log CFU/g Salmonella were recovered from the baseline on day 7; however, BIT at 2% significantly decreased pathogen populations to < 1.7 log CFU/g. S. Tennessee was the most sensitive among serotypes evaluated in this study. Germination rate of 0.5-2% BIT treated alfalfa seeds (85-87%) was not significantly different from control or chlorine-treated seeds (~90%). Significance: Results of the study indicate that BIT can potentially be used to control Salmonella contamination on alfalfa seeds.