Fruit juice

Concentrates get a bad rap. On the consumer side, the appeal of products (especially juice) from concentrate has declined markedly over the past several years because they simply don’t taste as good as fresh.

The reason that concentrates are of inferior quality is because they’re typically made using thermal evaporation. But a new concentration technology has emerged that doesn’t rely on heat. Forward osmosis can be used to create delicious concentrates that, when reconstituted, are indistinguishable from the original fresh product.

To learn more about the process and its benefits, we spoke with Olgica Bakajin, CEO and Founder, and Jennifer Klare, Senior Director of Applications and Operations, at Porifera.

Porifera didn’t start out in the concentration business. The company was formed in 2009 in response to a challenge from the Defense Advanced Research Projects Agency (DARPA) to come up with an energy efficient, portable solution for water purification. 

To deal with water that contained a lot of suspended solids and dissolved organics, the Porifera team developed a forward osmosis membrane technology that works in conjunction with reverse osmosis. From there, they took on wastewater treatment and water reuse, and it didn’t take long for them to realize that their process had many other applications. “If we can pull clean water out of waste, we can also pull clean water out of juice,” Bakajin says. “And what we are left with is the concentrate.”

A better process = a better product

Conventional concentrates are made using thermal evaporation, which produces high concentrations but degrades taste, quality, and nutritional content. There are a few other options that don’t use heat, but they have other limitations. 

  • Freeze concentration is typically done in a vacuum. This process is energy-intensive, and, while the final product is much better than what you get from thermal evaporation, you can still lose as much as 20% of the volatile compounds that give food its flavor. 
  • Reverse osmosis on its own doesn’t use as much energy, but it doesn’t work on highly viscous fluids and it can’t produce very high concentrations. 

Forward osmosis is a kinder, gentler processing method that meets consumer demands for tastier, less-processed products. It allows you to achieve the same high concentrations as thermal evaporation, but because it doesn’t use heat, it’s also able to maintain product integrity. “We can get to somewhere above 50, 60, sometimes 70° Brix without heating the product,” Bakajin says. “If you take the concentrate we make and dilute it to the initial concentration, the differences are minor. With a lot of products, the difference between our concentrate and not-from-concentrate is within the range of batch-to-batch differences.”

Energy efficiency and cost savings

A tastier product isn’t the only benefit of forward osmosis membrane technology. The process has operational, logistical, and environmental implications as well.

For one, it increases shelf stability. “For perishable products, the shelf stability can increase because you’re storing at higher osmotic pressures, higher concentrations,” Klare explains. “So something like grape juice will be a lot more shelf stable and you’ll have less loss.”

Lower volume also makes products easier and cheaper to store, handle, and ship. “If you’re concentrating something 5 or 6x, you can have a 5 or 6x smaller fridge,” Bakajin says. “So, if you’re growing something in California and shipping it to Asia, you can have one shipping container instead of 5 or 6. This represents a huge savings on shipping, especially if those containers are refrigerated.”

Forward osmosis also gives processors the potential to turn waste streams into value streams. “Sometimes waste is not necessarily waste,” Bakajin says. “It contains valuable components that could be turned into a sellable product.” 

For example, if a product ends up with a lower concentration than the manufacturer intended, it would typically be thrown away. “But with our technology, they can concentrate it back to either its original concentration or even higher,” Klare says. “At that point, it becomes a product again.” 

Often, Porifera finds that their customers who are interested in concentrating products eventually adopt wastewater solutions, too, or vice versa. “We’re working in the wastewater world, the agriculture world, and also the food and beverage world,” Klare says. “These three worlds are connected with different process streams, and our goal is to help customers reuse as much water as possible to maximize the efficiency of all of those streams.”

A wealth of product possibilities

Another advantage of forward osmosis is that it’s highly flexible and can make high-quality concentrates from a wide variety of products. “We can concentrate complicated materials in a way that nobody else can,” Klare says. “So you can make a product that’s totally new and different. That's the strength behind our technology.”

Currently, Porifera works primarily with clients in the juice, coffee and new beverage development sectors, but they’re always experimenting to find new applications. Recently, they’ve been concentrating wine. “We don't have a product in the market yet,” Bakajin says. “But if you can preserve the flavors and keep the alcohol, you get to a kind of fortified wine without actually fermenting it further.” Klare adds: “It's something we do for fun here, because why not?” 

Why not, indeed!

Klare attended PROCESS EXPO 2017, but this is Porifera’s first year as an exhibitor. “We’re exhibiting this year because our primary business is in the food and beverage space and PROCESS EXPO is the best place to exhibit our technology to food processors,” she says.

To learn how to make better concentrates using forward osmosis membrane technology, put Porifera on your PROCESS EXPO schedule. You’ll find them in Booth #4061.