The Effect of Replacing Sucrose with Glucose-Fruit Syrup on the Quality Indicators of Plombières Ice-Cream

Introduction. As functional products with a low glycemic index are becoming more and more popular, sucrose is gradually leaving food formulations. Glucose-fructose syrups (GFS) serve as substitutes for sucrose because they have a low glycemic index. The present research objective was to prove that GFS can be used for industrial production of functional foods, e.g. Plombières ice-cream with a low glycemic index. The list of technologically significant quality indices to be studied included dynamic viscosity, overrun, thermal and dimensional stability, and dispersion of the air phase and ice crystals. The experiment confirmed the synergistic effect of the mass fraction of fat and GFS on the dynamic viscosity, thermal and dimensional stability of the product, and a decrease of cryoscopic temperature. Study objects and methods. The research featured Plombières ice-cream. The control sample had a mass fraction of sucrose 14%; the experimental samples had a partial (3 and 5%) and complete replacement (14%) of sucrose. Rheological research methods helped to determine the dynamic viscosity; thermometric methods were used to measure the cryoscopic temperature of the mix and the temperature at unloading ice cream from the freezer, weighing methods – to determine the overrun, thermostatic methods – to establish thermal and shape stability, calculating methods – to define the share of frozen water, glycemic index, glycemic load, and sweetness. Results and discussions. The glycemic index of the test samples was 38–57, of the control sample – 60. The glycemic load per portion of 70 g was 5.3–7.8 (8.5 for control). The dynamic viscosity of ice cream mixes was 580–640 mPa·s (control – 563 mPa·s), the cryoscopic temperature –2.52–3.48°C, (control –2.32°C), and the temperature of unloading of the ice cream from the freezer at the share of frozen water of 50% was –5–7°C (control –4.6°C). As for thermal stability, after 90 min, the mass fraction of melt in the control sample was 35%, while in the sample with a complete replacement of sucrose, it was only 2%. In all the test samples, the structural elements had almost the same size. The diameter of air bubbles did not exceed 30 µm after hardening; the average size of ice crystals was 30–34 µm. The experimental data revealed no negative effect of replacing sucrose with GFS on the quality indicators of Plombières ice-cream. Conclusion. Glucose-fructose syrups can completely or partially replace sucrose while maintaining the quality parameters of Plombières ice-cream, e.g. dynamic viscosity, thermal and dimensional stability, dispersion of the air phase and ice crystals. The glycemic index decreased 1.6 times with a complete replacement of sucrose. Therefore, GFS can lower the glycemic index of Plombières ice-cream.