In-package pasteurization of dried basil leaves using radiofrequency heating

Abstract

Recent foodborne illness outbreaks associated with the consumption of low moisture foods such as spices have emphasized concerns over microbial food safety. In-package RF pasteurization method was evaluated for inactivation of Salmonella enterica in dried basil leaves. Samples were packed in polystyrene bottle provided with a steam venting film and was either positioned vertically (electrode gap = 16 cm) or horizontally (electrode gap = 10.5 cm) for RF treatment. The horizontally placed container achieved rapid heating of dried basil leaves as compared to the vertical placement and achieved more than six log reduction of both microorganisms within 35 s of RF treatment. E. faecium was more heat resistant than Salmonella, indicating its suitability as a surrogate for RF pasteurization of dried basil leaves. Quality analysis revealed no significant (P > 0.05) change in color, total phenolics, antioxidants, and volatile composition of dried basil leaves after RF treatment. Pasteurization of final packaged food product with steam vent minimizes cross-contamination and improves food safety.