3.3. Effect of different freezing conditions on the color
Fig. 4 shows the chromatic change of the surface of radish cylinders subjected to SF, IF and different UAF processes. Compared to the fresh samples, L*, a* and b* values of the products with different freezing processes were all decreased. Analyzing the L* values, no significant differences (p > 0.05) were found among those products frozen by immersion freezing with/without ultrasound irradiation. However, compared to products of SF, products of IF and UAF exhibited significantly higher L* values. After thawing, a* values of SF products was significantly lower than that of IF and UAF products, which might be the result of bigger crystal formation, more disrupted cell walls and drip loss.