Use of Temperature-Sensitive Gel for the Concentration of Escherichia Coli in Milk.

Temperature-sensitive gels (cross-linked, partially hydrolyzed polyacrylamide gels) with the property to absorb solutes less than 1 nm in diameter at 4°C and collapse at higher temperatures (190°C) were used to concentrate Escherichia coli from 2% low-fat milk. Milk samples seeded with bacteria were reduced eight-fold in volume with average recoveries of 40-66% at an optimal pH of 5.5. Repeated use of the gel did not affect its efficiency.