Whey-Ing up the Options E Yesterday, Today and Tomorrow
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International Dairy Journal 48 (2015) 2e14 Contents lists available at ScienceDirect International Dairy Journal journal homepage: www.elsevier.com/locate/idairyj Review Whey-ing up the options e Yesterday, today and tomorrow Geoffrey W. Smithers Geoffrey Smithers Food Industry Consulting Services, Melbourne, Victoria 3190, Australia article info abstract Article history: Whey, first generated more than 5000 years ago, was valued in the 17th through early 19th centuries, Received 20 October 2014 notably as a medicinal agent against some common maladies. However, for much of history, whey has Received in revised form been considered a waste by-product of cheese, casein and yoghurt manufacture. Nowadays, the intrinsic 24 January 2015 value of whey components, notably the proteins, has been recognised, and a large and growing body of Accepted 25 January 2015 scientific evidence now supports the many physico-chemical, nutritional and biological properties of Available online 7 February 2015 whey components. This evidence has established a foundation for their value as food and related in- gredients. Manufacturing technologies have been, and continue to be, developed for processing whey and for isolating functional whey components in a cost-effective manner. A diverse and expanding range of whey ingredients, foods, and related products has resulted. This paper traces the history and science of whey, highlighting the quirks, struggles, accomplishments, and emerging opportunities and challenges in the field. © 2015 Elsevier Ltd. All rights reserved. Contents 1. Introduction and background . ......................... 3 2. Yesterday e medicinal and menacing whey . ......................... 3 3. Today e functional and bioactive whey . ......................... 4 3.1. Environmental regulations . ............................................4 3.2. Science knowledge and technology advances . ........................................4 3.2.1. Nutritional quality . ............................................4 3.2.2. Food functionality . ............................................4 3.2.3. Mass liquid processing and drying technologies . .............................5 3.2.4. Sophisticated processing and valorisation of whey . .............................6 3.2.5. Biological and physiological activity of whey components . .............................7 3.3. Globalisation and market sophistication . ........................................8 4. Tomorrow e challenges and opportunities . ......................... 9 4.1. Awash with acid whey e what are the options? . .............................9 4.2. Improved efficiency and cost-effectiveness of processing . .............................9 4.2.1. Efficiency and effectiveness of cleaning . .......................................9 4.2.2. Efficiency and effectiveness of processing . .............................9 4.3. Embrace the unusual . ...........................................10 4.3.1. Blended ingredients . ...........................................10 4.3.2. Non-bovine whey ingredients . .......................................10 4.4. New options for functional peptides . ...........................................10 5. Conclusions . ........................ 10 References . ...................................................11 E-mail address: [email protected]. http://dx.doi.org/10.1016/j.idairyj.2015.01.011 0958-6946/© 2015 Elsevier Ltd. All rights reserved. G.W. Smithers / International Dairy Journal 48 (2015) 2e14 3 1. Introduction and background Technology developments over the past more than 60 years have resulted in increasingly sophisticated manufacturing tech- Whey was first generated serendipitously more than 5000 years nologies for processing whey and isolating whey proteins in a cost- ago, and since that time man's involvement with this by-product of effective manner, and this journey continues supported by ever cheese, casein and yoghurt manufacture reveals a chequered his- expanding knowledge regarding the properties of whey compo- tory e it has been a love-hate relationship! In the 17th, 18th and nents. With consumer demands for more nutritious and health- early 19th centuries whey was valued as a fashionable drink, as a promoting foods, these technologies are currently focused on medicinal agent effective against various maladies (e.g., wounds, retention of the nutritional and biological qualities of the whey gut ailments), and as an alternative to water for bathing. proteins and other components. A diverse and expanding range of In the 20th century, man's drinking (and bathing) habits functional whey and whey protein ingredients and foods, speci- changed, and together with a rapid expansion of dairy product alised formulations, bio-medical and personal care products, and manufacture, volumes of whey increased and it became a menacing components for pharmaceutical manufacture has been the result by-product of the dairy processing industry. A typical proximate (Smithers, 2008). Our relationship with whey has come full circle, analysis of sweet cheese whey (e.g., from the manufacture of from ancient wisdom to menacing by-product to nowadays a Cheddar cheese) and acid whey (e.g., from manufacture of casein or valuable raw material, supported by a growing body of science Greek-style yoghurt) is shown in Table 1. Notably, sweet whey knowledge and parallel technology developments. contains ~50% of the total solids found in milk, including most of Continued growth in the production of dairy products, notably the lactose, and ~20% of the milk protein. For much of the 20th cheese, has seen a concomitant increase in the volume of whey century, the industry has sought out the cheapest disposal method worldwide (currently >200 million tonnes per year), com- for whey, which has usually involved discharge into waterways, the plemented by a recent explosion in the volume of acid whey from ocean, municipal sewage treatment works, and/or onto fields. manufacture of strained (‘Greek’) yoghurt. The ‘ocean of acid whey’ While these disposal methods were tolerated for a time, the very from Greek yoghurt production, notably in the USA, represents one high Biological Oxygen Demand (BOD > 35,000 ppm) and Chemical of the industry's greatest financial and moral challenges in the 21st Oxygen Demand (COD > 60,000 ppm) of whey, primarily due to the century (Elliott, 2013). Others include, but are not limited to, high content of lactose but also the protein (Table 1), prompted the continuing downward pressure on costs, and how to better exploit introduction of strict environmental regulations in many jurisdic- the unique features of whey proteins, peptides and other compo- tions that nowadays prevent disposal of untreated whey (Mawson, nents. Science and technology will continue to provide answers 1994). including, for example, (i) clever approaches to isolation of whey In parallel with the restrictions on disposal of whey, the intrinsic proteins using charged ultrafiltration membranes (Arunkumar & value of whey components, notably the proteins, was increasingly Etzel, 2013; 2014); (ii) reducing the cost of cleaning through being recognised (Kinsella & Whitehead, 1989). A large and modification of equipment surfaces (Barish & Goddard, 2013); (iii) growing body of scientific evidence now supports the many phys- discovering and exploiting the unique properties of whey peptides ical, chemical, nutritional and biological properties of whey pro- to improve the performance of ingredients (Selby-Pham et al., teins and other components, and this evidence has established a 2013); and (iv) finding clever ways to utilise lactose (e.g., as a scientific foundation for their value as food and related ingredients. feed material for production of galacto-oligosaccharides) (Fischer & In parallel with this expanding scientific knowledge, the market- Kleinschmidt, 2014). place was becoming more sophisticated and receptive to the use- This review paper traces the history of whey and whey com- fulness of whey proteins and other components, but cost-effective ponents (notably proteins), highlighting the opportunities, ac- and industrially feasible technologies were needed for their complishments, and emerging challenges; and the role science and manufacture. technology has played in whey product development and in providing the industry with a bright future. Table 1 Component and related analysis of bovine sweet and acid whey, and comparison 2. Yesterday e medicinal and menacing whey with bovine milk.a Component or measure Sweet whey Acid wheyb Milk Consumption and topical use of whey has been prescribed for various therapeutic purposes (e.g., sepsis, wound healing, and Total solids (%) 6.3 6.6 12.8 stomach disease) over thousands of years (Hoffmann, 1961). Hip- Total protein (%) 0.75 0.75 3.5 Casein <0.05 <0.05 2.8 pocrates, the father of modern medicine, prescribed whey in 460 BC Whey proteinc 0.7 0.7 0.7 for the treatment of gastrointestinal ailments and skin conditions Fat (%) 0.1 0.1 3.7 (Susli, 1956), although the mechanism of action was unknown at Ash (%) 0.5 0.8 0.7 the time. In the 17th, 18th and 19th centuries, whey became a Lactose (%) 4.9 4.9 4.9 ‘ ’ pH >5.6 <5.1d 6.5e6.8 popular and fashionable functional drink available in inns and e À1 ‘ ’ BOD (mg O2 L ) >30,000 >35,000 140,000 other eating houses (so-called whey houses ) (Hoffmann, 1961), f À1 > COD (mg O2 L ) 60,000 ~80,000 218,000 somewhat akin to today's coffee shops and bistros. Samuel Pepys, À1 Energy (kJ L ) ~1100 ~1100 ~1710 the famous English diarist, frequented