Pasteurization of Saccharomyces cerevisiae and quality changes in clear and cloudy apple juice using intense pulsed light combined with mild heat treatment

Intense pulsed light (IPL), also known as high-intensity pulse light (HIPL), is an emerging non-thermal technology that uses light pulses of short duration, ranging from ultraviolet to infrared wavelengths, for microbial inactivation. This study aimed to investigate the sterilization of Saccharomyces cerevisiae in apple juice using IPL and mild heat. As the light intensity and treatment temperature increased, S. cerevisiae showed higher inactivation levels. When treated at 600 V and 50 °C for 10 min, clear and cloudy juices showed reductions of 3.95 log and 3.58 log, respectively. In terms of quality changes in apple juice due to pulsed light treatment, Brix and pH showed no change or a slight increase as light intensity, treatment temperature, and treatment time increased. Titratable acidity showed almost no change or a slight decrease. Color values showed a tendency for L and b values to decrease and a value to increase as light intensity, treatment temperature, and treatment time increased. Pulsed-light technology appears to be effective in sterilizing both clear and cloudy juices when combined with appropriate temperatures.