The Southeast is a net importer of milk and milk products. Milk must be imported from other regions at certain times of the year. Reverse osmosis (RO) is a new processing technology which could significantly reduce milk transportation costs between regions by removing half the water from raw milk prior to shipment. A network flow algorithm, which incorporates federal milk orders and solves for the least cost procurement pattern, was used to assess the impact of RO on southeast milk marketing orders under alternative raw product pricing scenarios.

Sweet cheese whey has been used to obtain whey cheese without the addition of milk. Pre-treated whey was concentrated by nanofiltration (NF) at different concentration ratios (2, 2·5 and 2·8) or by reverse osmosis (RO) (2–3 times). After the concentration, whey was acidified with lactic acid until a final pH of 4·6–4·8, and heated to temperatures between 85 and 90 °C. The coagulated fraction (supernatant) was collected and freely drained over 4 h. The cheese-whey yield and protein, fat, lactose and ash recoveries in the final product were calculated. The membrane pre-concentration step caused an increase in the whey-cheese yield. The final composition of products was compared with traditional cheese-whey manufacture products (without membrane concentration). Final cheese yields found were to be between 5 and 19·6%, which are higher than those achieved using the traditional ‘Requesón’ process.