Extrusion

Process Improvements Deliver Taste In Plant-Based Meat

Altruism isn’t enough to make plant-based protein competitive with livestock-based products. Advanced technologies, like twin-screw extrusion, help deliver on taste.

By Kevin T. Higgins, Managing Editor

It’s only a matter of time before McDonald’s patrons will choose between fried flora or fauna for their protein fix.

Plant-based protein is the hottest raw material trend in food processing, and meat analogues are the stars in giving Americans a choice between protein derived from animals or plants. Hummus may be the reigning champion in plant-based products, but burgers consisting of protein derived from wheat, soy, peas and other sources are gaining steam.

The reason is simple: Their taste now is on a par with the real thing.

One of the most recent and largest restaurant chains to add analogue burgers to the menu is A&W Food Services of Canada Inc., which is backing a July 9 rollout to its 925 outlets with a strong promotional campaign. A&W’s patties are supplied by Beyond Meat, which also added 469 TGI Fridays units to its foodservice distribution at the beginning of the year.

For bragging rights in the veggie-burger foodservice space, those clients pushed Beyond Meat, which recently announced a production expansion to 100,000 sq. ft. from 30,000 sq. ft. at its Columbia, Mo., manufacturing site, ahead of Impossible Foods Inc., which upgraded production with a new facility in Oakland, Calif. Unlike Beyond, Redwood City, Calif.-based Impossible only sells its meat analogue through 3,000 restaurants. Its biggest deal to date came earlier this year when White Castle added it to the menu at 140 outlets.

For decades, food scientists have developed formulations involving plant proteins to create replacements for meat and poultry. Archer Daniels Midland introduced textured vegetable protein, an extruded soy-based product, in the 1960s, but emulating the taste and texture of the real thing proved elusive until Garden Protein International broke through with its wet extrusion process.

Former restaurant chef Yves Potvin founded Garden Protein in 2003 and sold its Gardein brand four years ago for $154 million to Pinnacle Foods, which is being acquired by Conagra Brands. Speaking at a scientific session at July’s IFT 18 expo and conference, he noted, “In the last 10-15 years, the quality of the product has improved tremendously.” Much of that improvement can be attributed to his adoption of twin-screw extrusion technology and its ability to align the fibers in plant proteins.

With high-moisture, or wet, extrusion, the ratio of water to ingredients is 60 percent or higher, resulting in a viscosity that would be impossible to move through a single-screw barrel. The process is “very expensive,” and only a small fraction of meat analogue products use it, according to Potvin, but those are the products enjoying the greatest commercial success.

Throughput is limited — Impossible Foods’ new plant in Oakland, Calif., has a capacity of "only" 1 million lbs. a day, which would put it in the boutique packinghouse category — and prices are high. A&W charges $6.50 Canadian for the Beyond burger, equivalent to a complete meal deal for a hamburger. But a variety of factors point to bullish growth, not the least of which is wet extrusion’s ability to expand the audience beyond vegetarians and vegans.

Taste is king

Citing the resource-intensity of livestock — Potvin claims 600 gallons of water are consumed to produce 1 lb. of ground beef — he suggested environmental and social responsibility will drive growth in meat analogues. “The millennials are looking at the ethics of their food,” he says.

Sustainable production is a limited motivator, though. Fellow speaker LuAnn Williams, director-innovation at the Dutch research firm Innova Market Insights, cited survey data that suggests only 22 percent of U.S. consumers who increased their consumption of meat substitutes last year did so for planet-friendly concerns. By and large, healthy eating was the motivator, with 60 percent attributing increased consumption to health.

Taste, however, reigns supreme. Recent research by Mintel puts health a distant second to taste, with 52 percent consuming plant-based proteins because of the flavor, compared to 39 percent who cited health. Concerns about the environment (13 percent) and animal protection (11 percent) barely charted.

It’s an industry maxim that people eat with their eyes. Both Beyond Meat and Impossible Foods take that to heart with burgers that ooze artificial hemoglobin. Beet juice extract produces the “blood” in the Beyond burger, while soy’s leghemoglobin molecule delivers the myoglobin protein that gives Impossible Foods’ patty its red juice.

The good news about high moisture extrusion is that it is a continuous process. The bad news is the limited throughput. Scientists at General Mills Inc. have focused on altering an extruder’s barrel and die to increase throughput and lower costs.

Most extruders employ a rectangular cross-section die that can’t produce the parallel fibers necessary to emulate meat at high speed, according to Goeran Walther, principal R&D scientist for the Minneapolis food corporation. By designing an annular slit die with a cooling loop, his team was able to boost throughput by a factor of 4-6 times.

Walther spoke at an IFT session devoted to plant proteins and extrusion technology. Intellectual property was the main thrust of his presentation. At the outset of General Mills’ protein extrusion work, 2,500 “patent families” were identified, most of which were held by chemical companies concerned with the chemistry of thermoplastics. Nestle and DuPont Nutrition and Health are the biggest holders of food-related patents.

Walther is listed as one of four inventors on a patent issued Jan. 30 and assigned to General Mills for a die channel with a continuous loop cross-section for a uniform shear rate. Two related patent applications are pending.

The intellectual property behind Beyond Meat was developed by professors of biological engineering and chemical engineering at the University of Missouri. Fu-hung Hsieh, a former research engineer with Quaker Oats, Yuan-Chan Tu, Phimphan Kiatsimkul and Galen Suppes were issued a patent in 2010 for a process to convert vegetable oil into a polymer.

The patent was assigned to Curators of the University of Missouri, which licensed the process used to make Beyond Meats’ chicken-free strips in 2013. The licensing agreement required an investment in Missouri. Although Beyond Meat recently opened a 26,000-sq.-ft. R&D facility in Los Angeles, production continues in Columbia, Mo., in part to remain near the researchers who developed the technology.

Regardless if companies want to go the proprietary-knowledge or patent-protected route, they face an arduous product development process. Time, temperature and pressure are an extruder’s operating parameters, and methylcellulose is regarded as a workhorse in creating a firm texture. But how foodstuffs interact during the process is something of a black hole.

Trial and error characterizes development of meat analogues. “We don’t actually know what is going on inside of the extruder,” M. Azad Emin, a process engineer at the Karlsruhe Institute of Technology in Baden-Württemberg, Germany, confessed at IFT. “We have to have a better understanding of the processing conditions” and how ingredients react.

Thermocouples do not provide meaningful data on how the thermomechanical treatment changes the ingredients’ structure, particularly when temperatures spike as the machine’s rotational speed increases, Emin explained. His lab is trying to modify near-infrared sensors to measure radiated heat in different sections of the extruder barrel to better understand how high shear impacts outcomes. The distribution of stress varies throughout the barrel, he notes, and a better understanding on the material’s microstructure would lower the cost of making quality products.

Compared to the billions of dollars invested in dairy and meat research over the years, a relative pittance has been expended on meat analogue R&D over the past 50 years, Potvin points out. That is beginning to change, however, with some meat and poultry companies acquiring twin-screw extruders to advance their own analog development efforts.

Silicon Valley investors have backed Beyond Meat and Impossible Foods with hundreds of millions of dollars, giving each a leg up in developing meat analogues that emulate the real thing. Only in recent years have meat companies begun to re-imagine themselves as sellers of protein rather than animal flesh, and the largest ones have the financial resources to play catch up. The biggest, Tyson Foods, is an investor in Beyond Meat, announcing in December it was increasing its original 5 percent stake.

There’s still plenty of room for innovation. Rapeseed, fish scraps and canola protein isolate are among the protein sources being discussed to challenge formulations based on wheat, soy and pea proteins. Regardless of the formulation, however, the products that most resemble real meat likely will be produced with twin-screw extruders.