Sucrose crystallization in caramel

• Quantifies how sucrose crystal content influences quality and texture of caramel.
• A minimum of 30% crystal content will effectively eliminate cold flow.
• Crystallization alters continuous phase makeup and viscosity, influencing texture.

Caramel is a dairy-based confection with a continuous phase consisting of amorphous sugars and dissolved dairy solids with proteins and fat globules dispersed throughout. In some caramels, sugar crystals are desirable for their contribution to texture. The crystals disrupt the continuous phase, providing what is known as a “short” texture. At the extreme, fudge is known as a well-crystallized caramel. However, little is known about how crystal content influences the textural and physical properties of caramel.By changing sucrose to corn syrup ratio, type of corn syrup and water content in caramel formulations, the effects of sucrose crystal content on textural properties such as hardness, tensile strength, strain at break, and cold flow were studied. However, since crystallization is a separation process, changes in crystal content also resulted in variations in the viscosity of the continuous phase, which also influenced caramel textural properties. Thus, the results were interpreted as a combination of two, sometimes competing, effects. Increased crystal content decreased cold flow, with cold flow approaching zero as crystal content increased above 25–30%. Tensile strength and strain at break also decreased as crystal content increased, again reaching a minimum value at crystal content of about 25%. Hardness, on the other hand, was significantly influenced by the viscosity of the continuous phase and less so by crystal content. Knowing the effects of sucrose crystallization on textural properties allows caramel manufacturers to more precisely select the ideal formulation for their final product.