Challenges in dried whey powder production: Quality problems.

Whey is a high nutritional value by-product of the dairy industry. It is generally produced in large quantities and its disposal as wastewater poses environmental risks. For this reason, whey streams are used for the production of value-added products such as dried whey powders. However, there are several challenges related to whey processing that lead to low powder yield and quality, especially caking. These challenges can be addressed by optimization of product formulation and processing parameters. In this review, we discuss the effects of dried whey protein powder production stages and process parameters on the quality of the final powder product. The initial composition of whey used for dried whey powder production affects the final quality of the product. Generally, a high mineral and/or lactic acid content is not desirable since these constituents cause lactose-containing whey particles to adhere to the drying equipment surfaces, thereby reducing the powder yield. An effective lactose pre-crystallization is essential since high amorphous lactose content increases the stickiness of the dried-whey powder particles and induces caking during storage. Therefore, whey should undergo filtration and lactose pre-crystallization before spray drying. Studies show that it is possible to retard caking and improve the quality attributes of dried whey powders by optimizing the product formulation and processing operations.