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

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/cm(2)) 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/cm(2) 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/cm(2). Furthermore, the inactivation process conducted using vis-LED was affected by the juice's soluble solid contents and the calculated D(LED)-values were within the range of 116.3 J/cm(2) to 277.8 J/cm(2) 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.