Chemical Characteristics and Quality Changes of Syrup and Massecuite Across Boiling House Stages in Raw Sugar Manufacture

Abstract

The boiling house is a stage in sugar manufacture, in which clarified syrup is concentrated and crystallized into successive grades of massecuite, and sugar quality is influenced by physicochemical changes during processing. This study investigated chemical characteristics and quality changes of syrup and massecuites across major boiling house stages at Gunied Sugar Factory, Sudan, during the 2025 production season. Key parameters, including Brix, polarization (pol), purity, and color, were analyzed for syrup, A-massecuite, magma, and B- and C-massecuites to evaluate concentration behavior, crystallization efficiency, and impurity accumulation. Conversion of syrup to A-massecuite resulted in substantial increases in Brix (approximately 51.5%) and pol (approximately 52.9%), confirming effective concentration and crystallization under high-grade boiling conditions, while purity showed only a marginal change. As boiling progressed through magma and lower-grade massecuites, purity declined sharply from 89.37% in magma to 54.62% in C-massecuite, indicating progressive accumulation of non-sucrose impurities. Color intensity increased markedly from 14,516 IU in syrup to nearly 29,600 IU in C-massecuite, reflecting intensified thermal reactions and colored compound formation during repeated boiling cycles. One-way ANOVA revealed significant differences (p < 0.01) among stages. These findings emphasize the need for optimized pan control and real-time monitoring to enhance crystallization efficiency and sugar quality.