Cheese whey is considered the main by-product obtained by the dairy industry and it is derived from coagulation during cheese production. Half of cheese whey production is used in well-established processes, like production of fresh products, animal feed, and a source of high-added-value compounds, such as whey protein and β-galactosidase. Unfortunately, the use of cheese whey as raw material requires expensive processes. Therefore, a high proportion of this product is wasted and discarded into industrial effluent treatment stations. Different research groups have been studying potential strategies to valorize cheese whey. The goal of this chapter is to present the main characteristics of cheese whey and introduce the possibilities of using this by-product for new biotechnological purposes. The challenge is the arrangement of these processing systems with the players involved in the dairy industry. A joint action between them can turn cheese whey waste into high-added-value products producing zero dairy waste and honoring environmental legislation and public policies.
TopIntroduction
Cheeses are traditional products widely consumed throughout the world and in 2021, their production overcame 500 million tons (USDA, 2022). This number has been growing, since consumption of dairy products is increasing steadily worldwide (Pires et al., 2021; USDA, 2022). During cheese production, casein is used as a basic cheese component, while soluble whey proteins are separated into liquid whey waste. Therefore, cheese whey is considered the main by-product obtained by the dairy industry (Panghal et al., 2017).
Cheese whey composition depends on numerous factors such as milk origin, cheese production process, amount of water and addition of sanitizing agents. Regardless of the process, this by-product has proven to contain potential ingredients for the development of food products with improved nutritional characteristics and other functionalities (Pires et al., 2021). Therefore, from the total cheese whey production, 50% is currently being used in well-established processes, for example: 1) inside the cheese factories to produce fresh products (such as ricotta and whey butter), 2) to feed farm animals and 3) a source of high-added-value compounds for the food or pharmaceutical industries, mainly proteins of high biological value (whey protein) and lactose (Murari et al., 2019; Carrillo-Lopez et al., 2021).
Unfortunately, the use of cheese whey as raw material requires expensive processes such as ultrafiltration, evaporation, and fermentation, which are rarely adopted by small and medium-sized enterprises that cannot afford these costs. Therefore, a high proportion of cheese whey is still wasted and discarded (Bolognesi et al., 2021).
Due to the increase in food consumption and to the severe environmental regulations, the management of food waste and by-products is a challenge for the agri-food industries (Pires et al., 2021). The high level of lactose makes cheese whey a highly polluting element (Carvalho et al., 2013). This characteristic adversely impacts aquatic life due to the decrease of oxygen availability in water. Overtime, it causes a rapid consumption of oxygen, eutrophication, formation of foam, salinization, and acidification. In the soil, this industrial effluent can alter the physical and chemical composition of soil, resulting in decreased crop yield (Ahmad et al., 2019).
As the limiting factor for whey physic-chemical and biological treatment is its high cost for the industry, especially small and medium-sized producers, turning waste use practically unfeasible (De Almeida et al., 2021). In this context, different research groups have been studying potential strategies to valorize cheese whey and attract industries to invest in other whey-based products. These initiatives have a potential to turn this environmental problem into high value-added ecological products or by-products in food, fuel, health, pharmaceuticals, and plastic industries (Murari et al., 2019; Chalermthai et al., 2021; Argenta et al., 2021; Pires et al., 2021). In addition, the commitment of the entire dairy production chain towards a sustainable use of cheese whey in compliance with current environmental policies can contribute to zero waste disposal (Romani et al., 2018).
Finding lucrative alternatives for cheese whey applications are opportunities to solve environmental waste pollution problems. The goal of this chapter is to present the main characteristics of this important by-product from cheese production and introduce the possibilities of using cheese whey for other biotechnological purposes, reducing the impact of its disposal on nature, and developing competitive bioproducts and bioprocesses. In the future, several products with greater added value can be developed and cheese whey waste will decrease in the cheese productive chain.