Microwave pre-treatment reduced the browning of peach juice

摘要

Peach samples were pre-treated with microwave at 90, 270, 450, 720 and 900 W for 30, 60, 90 and 120 s, and juice browning was investigated during processing and storage. Polyphenol oxidase activity and ammonia nitrogen content decreased with microwave power enhancement or treatment time. The acidity of the peach samples initially decreased and then increased with prolonged treatment. The peach samples treated at 270 W preserved more polyphenol. The peach samples pre-treated at 270 W for 90 s or 450 W for 30 s demonstrated a reduction in peach juice browning. After 45 d of storage at room temperature, the juice colour value of the peach samples treated at 270 W for 90 s or 450 W for 30 s was 143.3% or 131.8% higher than that of the control samples, respectively. Microwave pre-treatment is a reasonable processing method for the effective prevention of peach juice browning.