Effects of Low Dose Electron Beam Treatment on the Quality and Safety of Alfalfa Sprouts

Abstract

Fresh Produce provides a rich assortment of the necessary vitamins and minerals needed to sustain a healthy diet. Alfalfa sprouts provide a concentrated number of compounds that have been shown to help support the body and aid in reducing the risk of serious health issues such as cancer and heart disease. Unfortunately, Alfalfa sprouts have also been linked to many foodborne illness outbreaks. In the past 20 years there have been over 30 outbreaks in the U.S alone linked to Alfalfa sprouts. The primary pathogens associated with Alfalfa sprouts are Salmonella spp. along with multiple stereotypes of Toxigenic non O157 E. coli. One cause of these outbreaks is the lack of thermal processing or other “kill steps” taken during the manufacturing process. These steps are usually skipped to help retain the desired sensory and nutritional qualities desired by consumers. However, this lack of a “kill step” leaves the Alfalfa sprouts vulnerable to pathogen contamination. The purpose of this study was to determine the effectiveness of Electron Beam (eBeam) in lowering both the natural bioburden and inoculated pathogenic organisms in Alfalfa sprouts. Additionally, we investigated whether treatment with eBeam at a max dose of 1kGy would aid in increasing the shelf-life of the sprouts. We established a max dose of 1kGy so that we would be able to see the benefits achieved following the current standards set by the FDA today. The hypothesis of this study was that the treatment of Alfalfa Sprouts with eBeam at the current maximum dose (1kGy) approved by the FDA would result in a significant reduction of both the natural bioburden and pathogenic organisms while increasing the shelf-life of the samples.

Results showed no statistical difference (p˂0.05) between treated and untreated sprout samples when comparing the texture and color sensory qualities. Microbiological studies revealed a 2.03 and 2.11 log10 reduction in natural bioburden of aerobic bacterial and fungal populations. The low dose (1kGy) eBeam treatment resulted in a 4.44 log10 reduction in the cocktail of 6 stereotypes of toxigenic non O157 E. coli inoculum. Quantitative Microbial Risk Assessment (QMRA) analysis utilizing the reductions found revealed that the reduction potential correlates to a theoretical drop in the probability of infection from the consumption of a normal serving size of alfalfa sprouts contaminated with E. coli from 0.044 to 0.000002.