Effect of Mustard Powder on the Survival of Salmonella ser. Typhimurium and Penicillium chrysogenum in Shredded Mozzarella Cheese

Abstract

Glucosinolates, components of mustard, when hydrolyzed, produce strong antimicrobial agents called isothiocyanates. The objective of this study was to evaluate the effect of mustard powder on the survival of Salmonella ser. Typhimurium and Penicillium chrysogenum in shredded Mozzarella cheese. Mustard powder at 0, 3, 5, 9, and 17% (w/w) was mixed into shredded cheese and packaged in polyethylene retail bags. The challenge study against S. Typhimurium and P. chrysogenum was conducted under modified (70% nitrogen, 30% carbon dioxide) and normal atmospheric conditions, respectively. Sample treatments were inoculated with the test organisms and stored at 4°C or 25°C. Increased concentrations of mustard powder resulted in an increased rate of reduction of S. Typhimurium. Addition of 17% mustard powder to the cheese reduced S. Typhimurium populations by greater than 5-log CFU/gram in 20 days. Treatments had no significant effect in inhibiting the growth of P. chrysogenum. Consumer preference of important sensory attributes and acceptability was significantly lowered due to the addition of mustard powder to shredded Mozzarella cheese (p<0.05). The studies provide evidence that addition of mustard powder may not be a viable strategy to enhance safety or quality of shredded cheese products.