Storage quality and microbiological safety of high pressure pasteurized liquorice root sherbet

In this study, the effect of high pressure processing (HPP) on wide-range quality characteristics (microbial, physicochemical, bioactive compounds and sensory properties) of liquorice root sherbet (LRS) were investigated. Pressure levels of 250, 355 and 450 MPa for holding times of 1 min and 5 min were applied to LRS. Full inactivation of yeast and mold count (YMC) and total coliforms (TCs) were observed at pressure-time combinations more severe than 355 MPa-1m and 250 MPa-5m, respectively. More than 6 log reduction in inoculated E. coli ATCC 25922 and Salmonella Typhimurium ATCC 14028 were achieved when the inoculated samples were treated at 450 MPa for 5 m. Even 450 MPa of pressure for 5 m applied, there was a persisting resistant total aerobic count, total decrease about 2.7 log. No significant differences were observed between HPP-treated and control samples regarding their pH, soluble solids, total phenolics, total flavonoids, antioxidant activity and glycyrrhizic acid content (P > .05). Consumer acceptability test showed that no differences were found between 450 MPa and 5m HPP-treated and control LRS in terms of their flavor and appearance. As a result, HPP could be used to extend the shelf life of liquorice sherbet without changing its physicochemical composition.