Food Engineering

Green fields produce green protein

April 1, 2010
Obtaining protein without damage required a membrane filtration process.

Sepallo’s membrane filtration system safely removes the protein from green plant juice that provides a low-salt, neutral-tasting, green ingredient for health food and other processors. Source: Koch Membrane Systems.


Sepallo Foods, a Canadian manufacturer of plant-based ingredients, devised a process that combines leaves from a variety of plants to create a successful line of leaf-juice protein powders. The product line includes powders created from the leaves of wheat, barley, oat, and alfalfa, all of which are high in protein, rich in chlorophyll and exceptionally clean from a microbial perspective.  Sepallo Foods, founded in 2001, markets the powders primarily as bulk ingredients to manufacturers in the food and natural products industries throughout North America.  

Growing the raw materials on its own farms, Sepallo harvests the leaves, extracts the juice, and dries them into a powder at its Barrhead, AB facility. The plant operates 24/7 and processes the leaves in tanks ranging in size from 800 to 100,000 gallons.  

During research and development, Sepallo discovered that the majority of the leaves contain extremely high levels of protein. Brad McNish, founder and president of Sepallo Foods, wanted to find a way to extract the protein from the juice.  Sepallo was already processing 19,800 gallons of green juice a day. Getting the protein out of the juice wasn’t difficult; the real challenge was maintaining its purity.

“We tried centrifugation, but we just couldn’t get the protein content of the mix over 45 to 50 percent,” McNish explained. “That wasn’t what we would consider a satisfactory result.” Heating the protein mixture was initially considered but scrapped. “The green leaf protein is very heat-sensitive,” he said. “One of its dominant elements is chlorophyll, and when you heat it, you alter its chemical profile, as well as changing its color. Keeping the color intact is important in a green product. What this told us is that we had to examine some type of cold process.”

McNish recalled a project that Sepallo conducted in conjunction with the Alberta Research Council using membrane filtration and wondered if a similar approach might work. He asked Koch Membrane Systems (KMS) to create a system that would separate the protein from the other nutrients in the juice in a way that would not denature the protein or damage the substrate (i.e., change the color). The protein content in the final product had to be at least 70 percent; the process, cold (less than 5