Removal of lactate from acid whey using nanofiltration

Abstract

The utilisation of acid whey by the dairy industry is limited by the high concentrations of lactate in the solution. In the present study, three commercially available nanofiltration membranes: HL, XN45 and DK were used in to evaluate the separation of lactose and lactate as a function of pH. Raw acid whey was used after microfiltration, while two laboratory prepared solutions comprising lactic acid and lactose; and sodium lactate and lactose were also tested for comparison. The rejection of lactic acid was found to increase with the degree of acid dissociation. About 50% of the lactate could be removed at pH ~3 due to the lower degree of dissociation. For all pH values tested, over 90% of the lactose was retained. The molecular weight cutoff and permeability of the membranes had little influence on the separation performance.

Preconcentration of yoghurt base by ultrafiltration for reduction in acid whey generation during Greek yoghurt manufacturing

“…In response to the remarkable consumer demand, the Greek yoghurt industry has tripled the production over last 5 years, generating 1.6 billion litres of acid whey per year (Chandrapala et al . , ). The reported typical figure for acid whey generation during commercial Greek yoghurt production is approximately 300 g/100 g of Greek yoghurt (Elliott ).…”

Feasibility of using electrodialysis with bipolar membranes to deacidify acid whey

“…Acid whey is a by‐product of Cottage cheese, Greek yoghurt and casein production, a serum phase separated after acid coagulation of casein fraction in milk. A large amount of acid whey is currently produced on a global scale (Chandrapala et al, ; ; ). However, these types of whey are rarely processed at the industrial scale due to their specific physicochemical properties.…”

“…The most significant feature of acid whey is a high content of lactic acid. The concentration of lactic acid in acid whey is approximately 10 times higher than that in sweet whey and is typically in the range of 0.5–0.6% w/w (Chen et al ; Chandrapala et al, ; ; ; Chandrapala et al ). A high content of lactic acid decreases the level of lactose crystallisation in whey (Saffari and Langrish ; Chandrapala et al, ; ; ).…”

“…The concentration of lactic acid in acid whey is approximately 10 times higher than that in sweet whey and is typically in the range of 0.5–0.6% w/w (Chen et al ; Chandrapala et al, ; ; ; Chandrapala et al ). A high content of lactic acid decreases the level of lactose crystallisation in whey (Saffari and Langrish ; Chandrapala et al, ; ; ). The predominance of lactose amorphous form along with a high hygroscopicity of lactic acid causes stickiness of lactose‐containing powders after spray drying and caking of powders during storage (Chen et al ; Carpin et al , ; Paterson ).…”

Size classification of precipitated calcium phosphate using hydrocyclone technology for the recovery of minerals from deproteinised acid whey

“…This material is difficult to convert into dried whey ingredients and is too high in organic matter for its disposal as effluent not to be an environmental concern (Chandrapala et al . ,). Acid whey is a by‐product from the manufacture of acid casein, acid‐coagulated fresh cheeses and strained (e.g.…”