Optimization of Preparation of Flavoring Syrup by Impregnating Jasmine Flower with Yellow Multicrystal Rock Sugar at Low-temperature

To clarify the influence of yellow multicrystal rock sugar on the yield of jasmine flavor syrup, the jasmine flowers from Hengxian County, Guangxi Province were taken as raw materials, jasmine flavor syrup by impregnating jasmine flowers with yellow multicrystal rock sugar was prepared at low temperature in this paper. Taking the yield of jasmine flavor syrup as an indicator, on the basis of single-factor experiments, response surface analysis (RSM) was used to determine the optimal preparation process of flavor syrup. And the quality of the obtained jasmine flavor syrup was analyzed. Results showed that, the optimal conditions were: Impregnation time was 130.0 h, the mass ratio of flowers to sugar was 1:1.2 g/g, and the size of yellow multicrystal rock sugar was 0.780 mm through 21 mesh sieve. Under these conditions, the maximum yield of jasmine flavor syrup was 39.82%. RSM predicted that the order of the influence of various factors on the yield of jasmine flavor syrup as follows: Impregnation time > the mesh of yellow multicrystal rock sugar > the mass ratio of flower sugar. Through the experiment, the jasmine flavor syrup with high soluble solid content, moderate acidity, low water content, bright color, containing jasmine's natural flavor, color and some thermal nutrients, high flavor peak and pure syrup taste was obtained, which met the sensory requirements of concentrated liquid (juice and slurry) for national food industry.