Use of Pulsed Electric Field for the Inactivation of Eupenicillium Javanicum Ascospores in Pineapple Juice

Abstract

Heat resistant molds are principle spoilage agents in foods and beverages with low acidity. The main objective of this work was to investigate the effect of 65 kV/cm PEF on the log reductions of Eupenicillium javanicum ascospores in 10–30°Brix pineapple juice as well as the modelling. Then, the first-order and Weibull parameters of the 65 kV/cm PEF inactivation of E. javanicum ascospores was estimated and compared. Further, the effect of PEF in combination with ultraviolet (UV) light treatment on the log reductions of E. javanicum ascospores was studied. Decreasing the soluble solid content of the juice from 30 to 10°Brix for 11.3 pulses increased the spore inactivation in pineapple juice by 2.7 log. A pulse number of 16 would be required by the 65 kV/cm PEF to achieve a 5-log reduction in juice. The Weibull model described spore inactivation by pulsed electric field. The estimated b-values for the 65 kV/cm PEF were 0.673 at 10°Brix, 0.041 at 20°Brix and 0.010 at 30°Brix, with n-values between 0.73 and 2.08. Although the combination of the PEF and UV light resulted in a slightly greater microbial inactivation, however two hurdles were not suggested. The results of this study confirmed the advantage of PEF technology for the inactivation of E. javanicum ascospores in pineapple juice.