Sandiness Prevention in Dulce de Leche by Seeding with Lactose Microcrystals

Abstract

Sandiness in Dulce de Leche is caused by a high concentration of lactose. In sweetened condensed milk, this defect is prevented by seeding with lactose microcrystals. Seeding has not been used in Dulce de Leche due to its high viscosity and due to contamination problems at the recommended seeding temperature (30°C). Preliminary experiments demonstrated that seeding at 40°C with a seeding material concentration of 6 g/100kg of Dulce de Leche effectively eliminated sandiness for as long as 6 mo. The high sucrose concentration (Ca. 44%) of Dulce de Leche reduced lactose solubility. Experiments demonstrated that a maximum seeding temperature of 54°C was possible using a seed concentration of 30 g/100kg of Dulce de Leche and agitating at the seeding temperature for 15min. This was valid for all formulations used in current industrial practice.