鲜切苹果果肉颜色及酚、酶的变化

摘要

Malus pumila Mill. cv. Cuiqiu fruits were used as material and cut into slices. The browning indexes, content of total phenols, polyphenol oxidase (PPO) and peroxidase (POD) activities were determined after culturing under normal temperature for 0, 15min, 30min, 1h, 2h, 4h, 6h, 8h, l0h, and 12h. The results showed that plenty of polyphenols released and fruits nutritious and flavor quality deteriorated. The activities of PPO and POD rose rapidly first and then decreased. Meanwhile flesh browning was rapid. The main reason of the browning was that polyphenolsk, PPO, POD was fully contacted with oxygen when fruits were cut.%以翠秋苹果(Malus pumila Mill.CVcv.Cuiqiu)果实为试材,切分加工后,常温条件下培养皿盛装,定时(开始时间、15 min、30 min、1 h、2 h,4 h、6 h、8 h、10 h、12h)调查褐变发生情况,并检测总酚含量及多酚氧化酶(Polyphenol oxidase,PPO)和过氧化物酶(Pemxidase,POD)活性.结果表明,苹果切分过程中总酚大量外释,导致营养、品质劣化,多酚氧化酶、过氧化物酶活性呈前期短时上升而后期逐渐下降的趋势;同时果实切面迅速褐化,果实完整性和物质区域化分布被破坏,使酚类底物、酚酶、氧气充分接触,这是造成褐变发生的主要原因.