Three Notable Advancements in Dairy Processing
Shelf-stable cheese snacks, chemical-free separation and more efficient pigging characterize process improvements in dairy.
Whether it’s new-to-the-world products or systems to reduce waste and improve purity, product innovation and process advancements are alive and well in North America’s dairy sector.
A case in point is Gay Lea Foods Inc., Canada’s largest dairy cooperative, where R&D scientists are taking a deep breath after intensive development work last year that culminated in the introduction of three distinct products: dehydrated cheese, curdless cottage cheese and coconut whipped cream.
Nothing But Cheese, marketed under the dairy’s Ivanhoe label, strikes clean label and healthy snacking notes, though a shelf-stable cheese with almost all water removed is a concept that most consumers have difficulty wrapping their heads around. In-store sampling was used extensively during the rollout.
Two varieties—Monterey jack and cheddar—are produced at the coop’s plant in Madoc, Ontario, where a 100 kW version of EnWave Corp.’s dehydration system that applies microwaves under vacuum was commissioned this summer. A year-long development process from bench top to pilot to industrial-scale production preceded market introduction, according to Milena Corredig, vice president-R&D at the Mississauga, Ontario-based co-op.
“The technology was quite new,” she notes, “and when it’s a completely new process, it takes a lot of energy from a lot of people to develop a commercial product.”
Various cheeses were tested to determine the impact on color, texture and flavor before Monterey jack and cheddar were selected. Depending on cheese type, 35-50 percent of total weight is removed, (For each kilowatt rating, 1kg of water is removed per hour by the machine.) The semi-continuous process has simpler, significantly shorter cycle times and reduced energy consumption compared to freeze drying.
A patent application is pending for Gay Lea’s Nordica Smooth cottage cheese. “Major formulation and process changes were required,” says Corredig, with equipment modifications and ingredients added to boost protein levels to 10g per serving.
People who don’t like cottage cheese and are drawn to Greek yogurt are Nordica Smooth’s target. “Cottage cheese is an old-fashioned product that appeals to people who want the curds, who want the dressing,” she observes. Those curds are very delicate, and processors take pains to keep them intact. With Nordica Smooth, curds are nonexistent and, in some cases, so is the fat, a value proposition Gay Lea hopes will appeal to those drawn to Greek yogurt’s nutritional value but don’t want the fat.
Completing the coop’s innovation trifecta is coconut whipped cream, a free-from product for people who like the idea of whipped cream but could do without the cream. Coconut fat is solid at room temperature, and that precluded the use of stabilizers but required different raw ingredients than conventional whipped cream. It’s non-dairy, gluten-free, cholesterol-free and lactose-free.
Nothing But Cheese is still finding its footing, with convenience stores and other grab-and-go outlets being eyed as likely sales opportunities. “Competing in the snack category is quite tough,” Corredig allows. As for R&D’s next project, she simply says, “We’re exhausted.”
Acid whey is described as the problem child of dairy separation, and because it is a byproduct of Greek yogurt production, it’s a substantial problem. Low protein content is part of it, but acid whey also poses filtration challenges by coating and tightening membrane pores, extending process time and requiring additional maintenance if components with commercial value are to be recovered.
Ion-exchange and electrodialysis usually are used to remove minerals while isolating desirable components of the stream. Trish Choudhary saw problems with both, either because chemicals were used in the first process or because purity levels were less than ideal with the latter.
A research scientist in the biopharmaceutical industry, Choudhary had a personal stake: Her 3-year-old daughter suffered from severe anemia and had to avoid iron-rich foods. Whey powder and high-protein weight-loss drinks could deliver the protein she needed, but they also are high in sugar. Traditional ion exchange is typically used to produce them.
“I felt I could find a better solution for infant formula and other high-purity products,” says Choudhary, CEO of E-Sep Technologies. “Four years later, here I am.”
“Here” is a chemical-free separation technology designed specifically for the dairy industry. The permeate left behind from cottage cheese, milk powder concentrate and whey processing has limited commercial value, largely because of the salt and other minerals that remain. High purity lactose, lactic acid and other components, on the other hand, are in demand and fetch prices 10-20 times higher per pound.
Assembling a development team that included electrical, mechanical and software engineers, Choudhary developed an electrical separation process that combines the best features of ion exchange and electrodialysis without the downside of chemicals.
E-Sep bundles six cells into each skid-mounted module, which usually is positioned downstream of ultrafiltration or reverse-osmosis equipment. Depending on the level of purity desired, a module might continuously process 200 gallons per hour, with additional modules added as volume requirements increase. Acid whey has a pH of about 4; regardless of the feed stream’s acidity, permeate exits at 5.5-5.8 pH.
Each cell has its own printed circuit board to regulate voltage and current and a transformer that ramps up “from zero to 600 volts in a split second,” she says. “Each cell is controlled independently, and they work together.”
Based on sensor feedback, the module’s software designates four cells for separation while two are flushed with water and regenerated. A small pump and tank attached to each unit performs CIP during downtime “to make those membranes squeaky clean,” she adds. “Membranes are replaced annually at a small fraction of the cost of conventional ones.”
Trials are underway at three dairy companies that plan to open new plants in 2018, and “a couple of companies” are negotiating pilot studies with an eye toward early-2017 commissioning, says Choudhary. “We not looking to process every gallon of permeate,” only waste streams from dairies that see an opportunity to deliver high-purity lactose for pharmaceutical use and lactic acid for bioplastics. “If it wasn’t for my daughter, I never would have thought about the dairy industry,” she reflects.
Ice, ice baby
Technical advances languish when developers fail to provide a complete solution. Such was the case with ice pigging, a concept developed at the University of Bristol in the UK.
Suez Advanced Solutions, a London-based firm specializing in municipal water systems, licensed Bristol’s intellectual property and complemented it with a mechanical system to provide a turnkey solution seven years ago. Since then, the technology has cleared lime and other deposits in water lines running up to five miles.
Ice pigging failed to spread beyond water piping until recently, when Suez secured rights to commercialize it in other industries. A UK ice cream plant is the first non-municipal water application, according to Matthew Stephenson, business unit director, and Suez is in discussions with global dairy processors, several of which previously considered applying the technology but held back because the university could not provide an engineered solution.
“The ice that we use is a pumpable slurry with the consistency of a Slurpee, or a Slush Puppie as we say in England,” says Stephenson. “It will flow around bends and clean out pipes that couldn’t be cleaned with a solid pig.” An additive such as salt or, in the case of a dairy, lactose is added to lower the freezing temperature and prevent the slurry from solidifying.
Dairies typically use process water to clear filling lines between production runs of yogurt and other products, resulting in waste where product and water mix. With ice pigging, recovery rates of 80 percent are typical, he says.
The ice-making machine measures about 6 by 10 ft. and is “largely plug and play,” he adds, with annual maintenance to check the charge of R404A refrigerant or a similar coolant. Push pressure is usually is 1-2 bar (14-29 psi) above operating pressure. The key is the semi-solid state that the ice assumes in the line. “That’s the magical part of ice pigging,” Stephenson says. “The rest is engineering and machinery.”
A little magic goes a long way, whether it helps improve processes or creates novel dairy products. But don’t sell engineering and machinery short in making magic happen.