Abstract:With the development of the market for flavoured foods and functional beverages in China, flavoured syrup with specific nutrition and health benefits are being used to meet the demand for flavored beverages. However, at present, flavored syrups are mainly produced by thermal concentration technologies, which can easily lead to the loss of heat-sensitive aromatic substances. Accordingly, in this study, jasmine flowers and yellow rock sugar were used as the raw materials to prepare jasmine flower flavor syrup via ultrasonic-assisted low-temperature solid osmotic dehydration (USOD). The optimum conditions obtained by single-factor experiments were: the amount of yellow rock sugar was 120% of that of jasmine (m/m), sugar size as 6~20 mesh, osmosis time as 168 h and ultrasonic time as 120 min. Under these conditions, the yield of the flavoured syrup was 41.40%, the contents of total phenolics and total flavonoids were 175.18 mg GAE/kg dw and 187.92 mg RE/kg dw, respectively, and the DPPH radical scavenging capacity of the flavored syrup was 313.55 mg Trolox/kg dw；Most flavour compounds of jasmine flower were effectively extracted, especially the alcohols, with linalool being 37.94%~46.06%, followed by benzyl alcohol (20.80%~23.90%), indicating that the SOD process had a significant effect on the extraction of flavor compounds. Therefore, the yield of flavored syrup was effectively improved and the flavor components and nutrients of jasmine flowers were retained in this study. This study lays a theoretical foundation for the development and utilization of flavored syrup.
