Whey - From waste to a valuable resource

Globally produced whey volume is estimated at more than 10 billion tons per year, and only 50 % of the total amount is processed and turned into products that are safe for the environment. In addition, whey entering wastewater treatment plants leads to disruption of the facilities' operation and further pollution of the environment, particularly water resources. In contrast, whey is the main source of whey protein and contains other valuable components for the human organism. Therefore, our target was to review recent studies to analyse whey as a component of wastewater from cheese factories and its impact on the treatment processes and as a valuable resource for further processing. Review results indicated the need for individual treatment processes for highly concentrated streams containing whey and alternative processing methods. The importance of avoiding whey entering treatment plants with the main wastewater stream and redirecting it for further processing was identified. Nevertheless, results showed that whey has a high nutritional value by all indicators: energy value (low-calorie product), biological value (a wide range of irreplaceable substances), physiological value (provides comprehensive support of most body systems and anti-infective action), and physiological activity (rich content of lactic acid bacteria). Further research on the possibilities of fractional extraction of whey's valuable components and the development of technologies that would allow for the complex processing of dairy raw materials is considered reasonable and prospective from the current needs and trends point of view.