Finding the whey
With demand for its functional and nutritional benefits going up, whey no longer goes down the drain.
The advancements in spray-drying, preparative chromatography and membrane processing technologies over the years have transformed whey from being an environmental contaminant in the waste effluents of cheese production plants to a platform of valueadded, whey-based food ingredients,” says Victor Huang, research fellow, Pillsbury Company, Minneapolis.
Whey offers a variety of functional benefits in applications, often fulfilling the role of more costly ingredients. Initially dried into sweet whey, the fluid whey stream that is a byproduct of cheese manufacturing is now filtered and dried into a whole host of specialty protein products. Lactose, or milk sugar, is also a value-added commodity and a byproduct of whey protein concentration.
Meanwhile, whey-based products add value beyond their functionality in application, as researchers continue shedding light on whey proteins nutritional contribution.
Demand for whey increases as researchers disclose newly discovered nutritional benefits. One of the key drivers of increased whey demand comes from protein supplementation of beverages and bars, and infant formulas and sports nutrition products. Whey is also used as a means of providing calcium fortification to dairy products and snack foods.
Breaking it Down
As a byproduct of the cheesemaking process, whey was once hauled back to the farms for disposal. In time, cheese processors began disposing of whey down the drain, at least until environmental regulation made this practice an expensive proposition. These days, all fluid whey not further processed becomes animal feed, particularly the lactose component, since the demand for whey protein in nutritional fortification places a high value on its use.
The fluid whey that is leftover from the milk used in making cheese is 93 percent moisture. It reportedly requires 100 pounds of milk for every 10 pounds of full-fat cheese, which leaves approximately 6.3 pounds of sweet-whey solids as a byproduct. Sweet-whey solids derived from cheddar cheese contain approximately 13 percent whey protein, 74 percent lactose, 1 percent fat and 8 percent ash.
New filtration technology brought a variety of whey-based ingredients to the forefront. While some types of filtration systems separate components by particle size, others remove water or separate out lactose, leaving a more concentrated protein fraction called whey protein concentrate (WPC). WPC products have a protein content that ranges from 25 percent to 89 percent. The composition of WPC-34 (for 34 percent protein) is similar to that of nonfat dry milk, and as such, may be used as a cost effective partial replacement, as indicated by U.S. Dairy: Markets & Outlook, August 2001, Vol.7, No.3. The most readily available forms of WPC in the United States are in 34 percent and 80 percent concentrations. Further filtration produces whey protein isolates (WPI), with a protein content greater than 90 percent.
Whey proteins contain all of the essential amino acids. One measure used to compare protein quality, and one endorsed by the USDA, is the Protein Digestibility Corrected Amino Acid Score (PDCAAS). Whey protein has a score of 1.0, the maximum allowable value. Whole egg and the milk protein, casein, also have a PDCAAS score of 1.0, while soy protein carries a score of 0.99 and wheat gluten a score of 0.25 as reported by the Whey Protein Institute.
Biological value (BV) looks not only at protein quality, but its bioavailability or absorption capability by the body. Once again, whey protein scores the highest possible value at 100, compared to casein at 80, or wheat gluten at 54.
Whey proteins contain bioactive components including beta-lactoglobulin, alpha-lactalbumin, glycomacropeptides, immunoglobulins, lactoferrin and bovine serum albumin (BSA). Beta-lactoglobulin, which binds fat-soluble vitamins, makes up 50 percent to 60 percent of total whey protein. Alpha-lactalbumin reportedly accounts for about 25 percent of total whey protein. This component is the major protein found in breast milk, and is therefore used to supplement infant formula.
Immunoglobulins, a component of colostrum, help boost the immune system. BSA, at 5 percent of total whey protein, binds fatty acids and aids in the production of the antioxidant glutathione. Glycomacropeptides also account for a moderate proportion of total whey protein at approximately 15 percent to 20 percent. Research indicates that glycomacropeptides raise cholecystokinin levels, a chemical substance that controls hunger. Finally, lactoferrin, a minor component of whey protein, has proven antioxidant capabilities. In fact, commercial application of lactoferrin as an antibacterial agent for meat has recently come to light, as reported by LLS. Dairy.
Whey More Functional
In addition to benefits associated with functionality, which include emulsification, gelation, whipping and water binding, whey’s neutral flavor makes it a user-friendly ingredient in a variety of applications, notes Bill Haines, vice president, business to business marketing, Dairy Management Inc.TM, Rosemont, Ill.
Applications for whey ingredients vary from bakery and confections to sauces to dairy products. Whey protein adds viscosity to soups, sauces, salad dressings, batters and yogurts. In spite of whey proteins’ solubility, foaming and emulsifying capabilities, certain conditions such as pH and ionic strength impact the ability of the protein to function fully. For instance, whey protein is least soluble at its isoelectric point – 4.2 to 4.5 pH for lactalbumin, and 5.3 to 5.5 for lactoglobulin.
Because of its lactose content, whey functions as a browning agent, and gives good crust color formation in baked goods. However, if there is an issue with whey use, it is often due to lactose. “The level of lactose within the whey used in formulation is such that you’re not going to affect a lactose-intolerant individual, but it still poses a problem for labeling, causing lactose– intolerant people to perhaps avoid certain products,” says Haines. Lactose may also pose a formulation issue, particularly in products such as ice cream, where high concentrations have a tendency to crystallize. Still, other whey– protein alternatives, such as WPI, hydrolzyed WPC or reduced-lactose whey that have either no lactose or reduced levels are available as alternatives.
Some applications of whey-based products include use of sweet-whey solids as a bulking agent or tenderizer in bakery products, and cultured whey as an anti-mold agent in pre-bake items, notes Huang. Whey protein also dupliGates or extends egg whites and is thus used in confectionery production of nougat for its whipping ability, adds Haines.
Breadings often benefit from whey– based ingredients. Sweet whey, with its high lactose content, contributes to color formation of breaded items. WPC gels when heated, which promotes adhesion of batters and breaders to their substrate.
Aside from their functional benefits, whey– based ingredients provide a cost-savings potential by replacing more costly ingredients or serving as bulking agents, notes Huang. In some circumstances, whey ingredients offer quality improvements by extending shelf life, as in the case of cultured whey.
Wheying in on Health Benefits
There are a lot of uses for sweet whey and WPC, but some of the recent production has shifted to the specialty items such as WPC-80, lactoferrin and glycomacropeptide, notes K.J. Burrington, coordinator, whey applications program, Wisconsin Center for Dairy Research, Madison. Although the United States has been slow to adopt these specialty products because of cost and somewhat less of a focus on nutrition in comparison to the Japanese, they are gaining momentum in usage, particularly in the area of sports nutrition.
In 1993, Next Proteins Inc. (formerly Next Nutrition), Carlsbad, Calif., introduced the first pure whey protein supplement to the United States. The company has had much success since that initial introduction, winning the 2001 “Gold Medal – Excellence in Taste” for its Designer Whey Protein Supplements, and the “Award of Excellence” for five flavors of its Designer Whey Protein Gourmet Bars. This is the fourth consecutive year the company has received gold medals for taste from the American Tasting Institute.
Next Proteins’ target audience is the health and fitness enthusiast. Body builders in particular reportedly derive benefits from these whey-protein supplements. “WPI and whey protein hydrolysate contain peptides that promote faster nutrient absorption and better nitrogen retention,” says Jason Stevens, brand manager, Next Proteins Inc. “We feel the benefits of whey protein are really untapped. Other associated benefits of whey proteins include lowering of cholesterol and improvements in bone health.”
Researchers reveal additional benefits associated with whey proteins and cardiovascular health as indicated in Bioactive Components of Whey and Cardiovascular Health, an applications monograph, U.S. Dairy Export Council, Rosemont, Ill. Although further human trials are needed to validate much of the laboratory and animal studies done, research revealed thus far indicates that hydrolyzed whey protein, which contains high levels of bioactive peptides, may reduce hypertension and dyslipidemia, risk factors associated with cardiovascular disease. These peptides must be bioavailable in order to be efficacious, which requires controlled processing conditions such as the proper selection of enzymes used for proteolysis and avoidance of exposure to extreme heat conditions.
“Whey has made a remarkable transition for a product that was once a problem as to where or how to dispose of it,” says Haines. “A lot of profitability at cheese processors can now be attributed to whey. Demand is so high that whey protein concentrates are in tight supply. From the cheesemaker’s standpoint, that’s not bad news. The future for whey is incredible. There’s a huge potential for the dairy industry.”
by Paula Frank Dairy RFD Editor email@example.com
Copyright Stagnito Publishing Oct 2001
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