Resistance of Eupenicillium javanicum mold spores to the light-emitting diode (LED), LED-assisted thermal and thermal processing in strawberry and apple juices

Abstract

The use of light-emitting diode (LED) technology for the non-thermal processing of foods is a major topic of interest among various research groups. This study is aimed at inactivating the Eupenicillium javanicum ascospores present in strawberry and apple juices using a combination of a visible LED (vis-LED, 430–630 nm, 216–420 J/cm2) and 90 °C thermal treatment, as well as to compare the findings with the inactivation done using thermal-processes alone. The results showed that violet-blue LEDs within the range of 430 and 460 nm with an energy between 300 and 420 J/cm2 were better for the inactivation of E. javanicum ascospores than the green and red LEDs which were within the 550–630 nm region with an energy range from 216 to 264 J/cm2. Furthermore, the inactivation process conducted using vis-LED was affected by the juice's soluble solid contents and the calculated DLED-values were within the range of 116.3 J/cm2 to 277.8 J/cm2 in juices with a Brix scale value of 10–20°. Finally, the inactivation rate obtained from combining a violet-blue LED with a 90 °C thermal treatment was similar to the rate of using the thermal treatment alone.