Vacuum/microwave drying technology supports food, cannabis

John Zhang, PhD, chief scientific officer, EnWave

Photo courtesy of EnWave

EnWave's REV pilot-scale machine can be used to make trial runs of potential products to be dried.

Photo courtesy of EnWave

And now for something completely different: dried, shelf-stable cheese snacks from Northern Tasmania.

No, this isn't a Monty Python skit. As exotic as it sounds, Ashgrove Farm had an off-the-wall idea to make dried cheese balls in an effort to use more of its dairy inputs. But to make its Amaze Balls of cheese, the company needed an effective method to dry the cheese.

At a loss for ideas on how to accomplish this task, and after some Google searches, the Elizabeth Town, Tasmania, dairy found a company in Vancouver, Canada, whose innovative new process might effectively accomplish the dairy's unique drying task. The company is EnWave, and it created a drying process which combines vacuum and microwave technologies to dry foods such as blueberries or cheese—and now has found application in cannabis flowers and hemp.

Founded in 1996 with the development of the first prototype REV (Radiant Energy Dehydration) machine at the University of British Columbia for dehydrating food and nutraceuticals, EnWave has gone through an ever-evolving process, acquiring additional patents for the technology. For certain food dehydration applications, the technology looks to be a perfect fit.

Having sold its first REV equipment to a Canadian blueberry processor, and then the Tasmanian dairy and over 25 other partner companies, EnWave has been busy developing new applications, extending into the burgeoning cannabis industry. Most recently, the company has been working with the U.S. Army to help further the development efforts focused on improving the quality of Close Combat Assault Rations, food that keeps our troops alive and nourished during operations.

I spoke with John Zhang, PhD, chief scientific officer to learn more about this technology and company.

FE: Tell me a little about EnWave's history. Was it started primarily as an R&D firm?

John Zhang: Correct, EnWave was a technology spinoff from the University of British Columbia in Vancouver. Over the years, the company had successfully raised sufficient funding to develop and improve its proprietary vacuum-microwave technology to industrial scale and reliability.

The goal was to create a technology that could offer a uniform, fast drying option with flexibility on final moisture content. This allows companies to create products that are otherwise impossible to produce using existing technologies on the market.

FE: Has EnWave developed its own patents or has it licensed technology?

Zhang: EnWave either owns or has active applications for more than 20 patents, most recently a cannabis process patent application. EnWave licenses its game-changing REV technology to royalty partners. Our engineering and food science teams work to create additional value for our partners through innovation and continuous improvement.

FE: How does the vacuum/microwave technology work?

Zhang: Vacuum can lower the boiling point of water. At the right vacuum levels, water can actually evaporate at room or body temperatures. Microwave provides volumetric and instantaneous energy transfer to the material being dried. The combined effect is a gentle and rapid dehydration process that allows for the retention of nutrients, colors and flavors in food—and the retention of THC/CBD in cannabis material.

FE: How does it differ from other drying technologies, e.g., freeze drying or spray drying?

Zhang: Due to the short drying time, REV dryers are much smaller in footprint than conventional freeze dryers for the same throughput. Although the nutrient retention is on par, REV technology can provide better color, flavor and novel structure in a lot of cases. Also it's less costly than freeze drying. In terms of spray drying, REV not only can provide lower drying temperature, but also it is easy to process solid pieces and thick liquids such as 100% honey and maple syrup, which cannot be done by spray drying.

FE: Are there other combined technology systems on the market? If so, how does yours differ?

Zhang: We are the global leader in vacuum-microwave dehydration and the only reliable commercial scale technology available on the market, offering continuous machines of greater than 100 kW in rated power. EnWave evaluated many ways to deliver a uniform microwave field and patented the versions that provide the most uniformity, consistency and reliability for our royalty partners.

FE: What food applications lend themselves to REV technology?

Zhang: Many foods are dried commercially with REV equipment, which include but are not limited to fruit, vegetables, ready-to-eat meals, dehydro­frozen applications and dairy products. EnWave launched Moon Cheese, a 100% natural cheese snack product as a proof of concept to demonstrate the viability of REV technology in 2013. The company's success over the last five years has helped showcase the benefits of this technology growing from a few hundred thousand in revenue to over $16 million last year. Since 2013, an additional 11 licenses to produce REV-dried cheese snacks have been signed, including the license with Ashgrove Farms.

FE: Why dry cannabis?

Zhang: Fresh cannabis flowers need to be dried for both smokable products and for the extraction of purified cannabinoids and terpenes. After harvesting, traditionally the flowers are dried in large drying rooms for 5-7 days. With REV, the drying can be achieved in 35 minutes. This also prevents molding and spoilage during the drying process which is a known issue in the industry.

FE: Today, what part of your sales is cannabis related?

Zhang: Greater than 50%. After years of drying organic materials, specifically food and ingredients, cannabis was a natural new market for EnWave. Cannabis and hemp companies harvest hundreds of acres at a time and require machines that can process large volumes of crop quickly. At this time, EnWave is not active in the United States for the drying of cannabis and won't be until it is federally permissible.

FE: Are you selling or leasing equipment? What is your go-to-market model(s)?

Zhang: EnWave sells REV drying equipment under license agreements. We will also lease smaller scale batch units that allow potential partner companies to conduct R&D and de-risk the adoption of the technology. All relationships begin with a mutual non-disclosure agreement.

After initial sample trials, the collaboration may advance to a Technology Evaluation and License Option Agreement, which typically provides six months for the partner to evaluate its target business case and finalize product development. If the partner decides to commercialize REV-dried products, a royalty-bearing license agreement will be entered into, providing the partner company with certain exclusive rights. An agreed upon royalty is then remitted to EnWave on a quarterly basis tied to each royalty partner's commercial success.

FE: How do the costs of using this technology compare roughly with other drying technologies? What are advantages/tradeoffs?

Zhang: Due to the rapid drying speed, REV is more cost effective than freeze drying. The only known disadvantage is that the rehydration rate is slightly lower than the freeze dried products. REV provides a much better product quality than air dried products.

FE: Do you offer consulting/testing potential products on REV?

Zhang: Yes, we provide collaborative consulting and are always testing new products and processes for our existing and potential partners. EnWave's success is built on our partners’ success.

We offer a few product development packages that allow potential partners to see the technology in action and learn how it applies to their specific needs. EnWave offers pilot plant rentals where our food science and REV experts work with a company's team to produce sample products.