Effect of ultrasound waves on quality and antioxidant activity of asparagus during storage

The effect of ultrasound waves (20, 60 and 100kHz) on quality and antioxidant activity were investigated, while respiration rate, color, hardness, total phenolic content, ascorbic acid, antioxidant activities, bacterial count and mold counting were evaluated.The results indicated that ultrasound waves kept hardness and the contents of ascorbic acid, promoted accumulation of total phenolics in the middle stage of storage, reduced the numbers of bacteria and mould of asparagus, inhibited the respiratory rates, but had no significant effect on color.The longer the time of after storage, the worse the effect of ultrasound waves on asparagus.Ultrasound wave was an effective integrated freshness-keeping technique for extending storage life.