Optimization of sorbitol, fructooligosaccharides and sugar levels in the syrup based on physicochemical properties and sensory acceptance of healthy, sweet egg yolk drop (a traditional egg-based dessert) using response surface methodology

Abstract

ABSTRACTSweet egg yolk drops are one of the traditional Thai desserts made by dropping egg yolk batter into a boiling syrup with high sugar concentration to form teardrop shapes. The objectives of this study were to optimize the ratio of sugar substitutes (sorbitol and fructooligosaccharides (FOS)) and reduce the amount of sugar in syrup for the development of sugar-reduced egg yolk desserts. Effects of three ratios of sorbitol to FOS (25:75, 50:50, and 75:25) and four percentages of sugar reduction (25, 50, 75, and 100%) on the physical, chemical and sensory properties of desserts were also investigated. Results indicated that increasing the ratio of sorbitol and decreasing the percentage of sugar in syrup led to desserts with decreased color a* and b* values, bulk density, hardness, cohesiveness, soluble fiber, and reducing-sugar content. The opposite effect was observed in desserts made with syrup, which had higher ratios of FOS and lower levels of sugar. The optimum formulation of desserts based on response surface methodology (RSM) contained a ratio of 25:75–30:70 of sorbitol to FOS and 60–65% reduction of sugar in syrup. The comparison of the predicted values from the model of the optimized dessert with experimental values showed that the model was well-fitted. Moreover, the optimized dessert had higher sensory acceptability when compared to the full-sugar sweet egg yolk drops. Therefore, the results indicate that sorbitol and FOS could be used as sugar substitutes in syrup to produce a healthier and lower calorie egg-based dessert.

Keywords

• Egg-based desserts
• fructooligosaccharides
• response surface methodology
• sorbitol
• sugar reduction
• sweet egg yolk drops