It is well known that some water soluble compounds such as L-ascorbic acid could leak out from broccoli during the thawing process. As can be seen from Fig. 6, the variation in the L-ascorbic acid content agrees well with the trend in the drip loss of broccoli. The UAF at 0.250, 0.324, 0.378 and 0.412 W/cm2 better persevered the L-ascorbic acid content of broccoli compared to that by the normal immersion freezing (p < 0.05).