Effects of intense pulsed light on apples and pears for convenience infant food: inactivation of Bacillus cereus spores and changes of antioxidant activity

This study evaluated the sterilization effect of intense pulsed light (IPL) on Bacillus cereus spore-inoculated apples and pears, and the changes of antioxidant activity over a 12-day post-treatment period. The spore reduction rate for both fruits significantly increased with increasing treatment fluences (0–12 J/cm2). No shoulder phenomenon was observed, and the tail phenomenon appeared at 2.19 J/cm2. At a 12 J/cm2, 2.34- and 2.83-log reductions of spores occurred with associated temperature increases of 2.3 and 3.5 °C in apples and pears, respectively. During storage of 0–12 days, IPL treated-fruits exhibited the highest antioxidant activity on day 3, followed by a gradual decline. IPL treatment of apples and pears increased the ABTS radical scavenging capacity by up to 1.22 and 1.34% and the DPPH by up to 0.53 and 2.06%, respectively. The total polyphenol and flavonoid contents of IPL-treated fruits were higher than those of their untreated counterparts throughout the storage period.