Effect of thermosonication on the quality of liquorice root sherbet

The objective of this study is to investigate the applicability of thermosonication technique for the production of licorice sherbet having a reasonable shelf-life. In this concept, Escherichia coli K-12 was used as the target microorganism to determine the appropriate pasteurization norm of temperature-time. It was determined that thermosonication treatment at 60 °C for 20 min on licorice sherbet has resulted in 7.08 log cfu/mL reduction in the E. coli K-12 number. The second part of the study revealed that thermosonication treatment (60 °C for 20 min) did not cause a significant change in the lightness and yellowness values with respect to the fresh samples. The total color change for thermosonicated samples was 0.85. On the other hand, turbidity values of thermosonicated samples were significantly (P<0.05) higher than the fresh ones. Color values, pH and total titratable acidity, turbidity, antioxidant capacity, total flavonoid and total phenolics content of thermosonicated and fresh samples were monitored for 28 days. Storage part of the study showed that thermosonication has no negative effect on the physicochemical properties of licorice sherbet samples except the turbidity. Similarly, no significant loss on the bioactive component content of thermosonicated licorice samples was observed. This study can give idea to the potential licorice sherbet producers about the pasteurization norms for the preference of thermosonication technique, followed by the shelf-life of the produced sherbets. By this means, it would be possible to produce a value-added product form a nationally grown plant as a contribution to national economy.