M. W. Kearsley

The chemistry and metabolism of the starch based sweeteners

Abstract Starch hydrolysates (glucose syrups), widely used in the food industry, have recently been modified by hydrogenation on a commercial scale, making available a new range of carbohydrate compounds with distinctive physico-chemical and physiological properties. Hydrogenated glucose syrups may be used in foods to control nonenzymic browning reactions, moisture absorption, sweetness and fermentability. The degree of control is directly related to the degree of hydrogenation and to the extent of initial hydrolysis of the starch. Furthermore, good complexing power toward mineral components of foods allows the control of cation-catalysed oxidation processes such as vitamin C destruction. Physiologically, hydrogenated syrups may offer certain advantages in foods for the diabetic market. Blood glucose and serum insulin levels after ingestion may remain lower than after conventional carbohydrates.

Significance of starch-sucrose interaction in extrusion cooking

The possibility of a starch-sucrose interaction was investigated because it was suggested that such an interaction could be significant in reducing extractable sucrose in extruded starch-sucrose systems. Differential scanning calorimetry indicated an endotherm at 153°C for sucrose levels of 50% and above. The enthalpy of the endotherm was dependent on the sucrose and moisture contents. Physical complexing of sucrose by starch in high sucrose mixtures was suggested. Water solubility studies and HPLC analysis on extruded starch-sucrose feeds revealed that at 35% sucrose level all the sucrose added was dissolved by water. There was no significant (p>0.05) interaction between starch and sucrose at sucrose level less than 50%.