دانلود رایگان مقاله اثر بعضی از شیرین کننده رژیمی بر خواص رئولوژیکی شکلات

Abstract

Chocolates with reduced calories have become popular among consumers and manufacturers. One way of manufacturing chocolate with reduced calories is to replace sucrose with some alternatives. Effects of different bulk sweeteners (maltitol, isomalt, and xylitol) with different particle size intervals (PSI) (106–۵۳, ۵۳–۳۸ and 38–۲۰ mm) on rheological properties of molten chocolate were investigated. The best model that fit the rheological data was Herschel–Bulkley model. Maltitol resulted in similar rheological properties of chocolate compared to sucrose and thus can be a good alternative. Isomalt resulted in higher plastic viscosity while maltitol resulted in higher yield stress than others. As the particle size increased the plastic viscosity and the yield stress increased. The differences in rheological properties of chocolate with different bulk sweeteners were caused by differences in solid volume fraction and particle size distribution (PSD). A substitute with large particle size should be chosen to replace sucrose for improving rheological properties of chocolate, but the particle size should be small enough to obtain good sensory properties.

4. Conclusions

Herschel–Bulkley model was the best model that fit the rheological data of chocolate samples. Maltitol resulted in similar rheological properties of chocolate to sucrose, and thus it may be recommended as a good alternative to sucrose in chocolate formulations. Chocolate with isomalt resulted in higher plastic viscosity while xylitol resulted in higher flow behavior index. Addition of bulk sweeteners on volumetric basis (especially if density of the sweetener is different than that of sucrose) may reflect the effect of sweeteners on rheological properties more accurately. Plastic viscosity and yield value of chocolates increased with decreasing particle size of bulk sweeteners. Large particle size would result in better rheological properties for manufacturing process, but it may adversely affect sensory properties. Further experiments with better control of PSD of bulk sweeteners and chocolate mix, and varying conching conditions should be conducted to determine the effects of bulk sweeteners on physical and sensory properties of chocolates.