Efficacy of Nanoemulsified Benzyl Isothiocyanate and Carvacrol in Reducing Salmonella Contamination in Alfalfa Seeds and Sprouts.

Abstract

This study evaluated the efficacy of nanoemulsified benzyl isothiocyanate (NBIT) and carvacrol (NCR) to reduce Salmonella contamination on alfalfa seeds and sprouts. Given the susceptibility of sprouts to microbial contamination during germination, improved interventions were needed to enhance food safety without compromising product quality. NBIT and NCR were applied to Salmonella-inoculated seeds at high (6.3 log CFU/g) and low (2.4 log CFU/g) inoculum levels and their impact on Salmonella populations, seed germination, sprout quality (length and weight), and visual appearance was assessed. Results revealed that both NBIT and NCR significantly reduced Salmonella populations and most treatments did not adversely affect seed germination or sprout quality. Treatment with 2.0% NBIT achieved reductions of up to 2.4 log CFU/g on seeds and 6.4 log CFU/g on sprouts after 4 days at the low inoculum level. However, treatment with 2.0% NBIT resulted in an 18.8% reduction in germination that occurred at the high inoculum level and a 10.7% reduction at the low inoculum level, along with a slight decrease in sprout size. In contrast, treatments with 0.5% and 1.0% NBIT, as well as 2.0% NCR, reduced Salmonella on seeds by 1.5-2.0 log CFU/g, regardless of inoculum level, and achieved reductions of 5.0-6.4 log CFU/g on sprouts at the low inoculum level. In addition, NBIT (0.5% and 1.0%) and NCR (2.0%) preserved seed germination rates and sprout quality metrics, including length, weight, and visual appearance, comparable with untreated controls. These findings highlight the potential of NBIT and NCR as effective antimicrobial agents for improving the microbial safety of alfalfa sprouts without compromising quality.