Whey is subjected to ultrafiltration to retain about 10% of the T5, whilst the permeate is demineralized to 7% or less ash in the final product and dried to 3% moisture. The product, containing (in DM) 75% or more lactose, 6% or less protein and 8% or less minerals, is hydrolysed, e.g. with beta-galactosidase. It may be used for replacing sucrose, in the manufacture of a range of foods. Applications include chewing gum, fondants, nougats, chocolate, bakery and confectionery products as well as cream and yoghurt.