Chemical engineering and controls technology came into play in refining a release agent that relies on the principle that less is more.

John P. Starr, president, The Amarna Co., Delta, CO

A fresh set of eyes not only can improve an existing product, it can find new applications. The story of The Amarna Co. is a case in point.

A chemist developed Amarna’s water-based release agent in the 1970s as an alternative to animal fats and oil-based pan release agents. Oil leaves a carbon residue and damages the silicone glaze on most baking pans, forcing bakeries to periodically have them reglazed. The water-based agent overcame those issues, but it also degraded relatively quickly. When John P. Starr took over the company, he began experimenting with new formulations. He also began refining the delivery system and, along the way, discovered the release agent had much wider applications than the inventor imagined.

Starr graduated with a BS in chemical engineering from the University of Arkansas, then began a long career with Alcoa. After retiring, Starr and his wife operated a bed & breakfast in Colorado Springs, CO, where he met Oran Strouss, founder of The Amarna Co. A onetime Kraft Foods employee, the octogenarian Strouss was looking for a buyer for the business he founded in 1979, and six weeks later Starr received an unexpected offer for his B&B. In 1998, Starr became the firm’s new owner. In 2001, he filed the first of two patent applications covering the release agent and its method of manufacture.

FE: What did you want to improve in the original release agent?

Starr: Oran Strouss came up with a water-based release agent for bakery applications that prevented carbon build-up. The negative was that the agent only had a 60-day shelf life. I began experimenting with different formulations and came up with a release agent with a three-year shelf life. We gave it to some bakers for trial. They said it released product just as well as oil-based agents, but that it also cleaned contact surfaces.

FE: Was the new formulation the result of trial and error or happenstance?

Starr: The original formulation had a low pH but a different antibacterial structure and different monoglycerides and diglycerides, which are common dough conditioners. Originally it didn’t include lecithin, which is a very popular food release agent. Oran included lecithin in a reformulation, but he wasn’t able to get it to spray well. We use a different chemistry and are able to spray about three times as much lecithin.

A design of experiments was used in the reformulation work. When you’re cold calling on a chemical compound, you say, “This is as far this way it will work, and this is as far that way it will work.” It provides an organized matrix to reduce the number of experiments as you alter different variables and home in on what works best. Although the protein levels of lecithin are very low, it now is classified as an allergen concern. Design of experiments is very useful as we rebalance the matrix with sunflower lecithin or allergen-free formulations without losing the sprayability, surface-cleaning and shelf-life properties of the original formulation.

FE: What functionality does lecithin bring?

Starr: Lecithin is both hydrophobic and hydrophilic, which makes it particularly useful on a conveyor belt. One end of this amphoteric molecule attracts water, while the other repels it. When the fluid is sprayed on, the hydrophilic end, which also loves to bind to metal, adheres to the food contact surface. The hydrophobic end is oriented outward and tends to prop up moist product that comes onto the belt. If we could limit the spray to one molecule of thickness, we could optimize release. With oil, release relies on creating a barrier that floats the product off.

Some makers of oil-based release agents include lecithin in their formulations, but lecithin is highly viscous. It is hard to dispense, and it gums up the sprayer. Our product sprays like water, which is not supposed to happen. And typically the water evaporates after the belt has moved a couple of feet, leaving only the release agent.

Dryers used for French fries and other products have been outfitted with spraying systems for water-based release agents, resulting in significant reductions in water used for belt cleaning. Source: The Amarna Co.

FE: Was the addition of lecithin the key to performance improvement?

Starr: Lecithin doesn’t do much to solve carbon build-up, and that was Amarna’s original goal. The cleaning effect comes about because of the dough conditioners and the vinegar and other acetic acids in the compound. Lecithin by itself doesn’t do much to remove carbon from a belt. Likewise, monoglycerides and diglycerides don’t remove much carbon. But if you put both compounds on, you get a synergistic effect. The acid normally would act so slowly that it wouldn’t be of much use.

Citric acid and sodium benzoate help to lower the pH to about 3.6, which puts it into the zone of an acidified food where you don’t have any microbial concerns. You can challenge this with listeria, salmonella, yeast or mold. It will zap all of them.

FE: What kind of delivery system did you engineer?

Starr: If you used regular spray-nozzle equipment, it would flood a surface. We use hydraulic pressure, without any air and at very low pressure, 40 psi or less. Oil-based systems use air atomization to create very small particles, and oil ends up coating the entire plant. With hydraulics, we get next to no overspray. It’s very direct and precise. Performance excels when the weave of a belt is close.

FE: Are off-the-shelf nozzles appropriate?

Starr: The guns we use are from Spraying Systems and are outstanding equipment. They operated at 6 cycles a second. Thanks to controls technology, we were able to boost that to 100 cycles a second, with as little as 0.1 grams of release agent sprayed per cycle. A pound of liquid is enough to coat 454 bread pans.

A tiny ball bounces back and forth between two solenoids in the spray gun. The faster air pulses, the faster the cycle. We’re working with some advanced controls from Allen-Bradley and expect to be able to get to 10,000 cycles a second, with modulation, in a few months. The advantage is to very precisely control the amount of product that is deposited. Instead of trying to hit a belt or a pan with a circular pattern, the surface will be hit with a flat spray, restricting the amount of fluid for better performance.


FE: The technology was designed for baking. Is that still the most common application?

Starr: When the agent is sprayed on dough, a topping adheres better, which is an added advantage, but we’ve actually been able to generate more savings in other food processing environments. Frozen vegetables, roasted and dried corn and peppers, IQF foods where water degrades flavor or reduces shelf life are our major thrust.

As with potatoes, water removal is important, but the big advantage for many manufacturers is a reduction in water usage. Some plants that were consuming 100,000 gallons of water a day to wash down belts have reduced consumption 80 percent. To achieve that, a big potato processor might use 330 gallons of the release agent a month. That’s how we can say we’re cheaper than water to use.

Some plants have gone from cleaning and sanitizing a belt once every eight hours to once every two weeks. If downtime to clean is an hour, it’s like adding two shifts every two weeks.

FE: Give an example of how the system is used.

Starr: After potatoes are blanched, they are transported to a dehydrator, then either par-fried or frozen. Removing water in the two- or three-stage dehydration process is important to keep fries from sticking together if frozen or, if fried, from releasing a lot of water and rapidly degrading the oil. Some processors use Teflon-coated belts while moving product in and out of the dehydrators, but the Teflon flakes off, and the belt has to be recoated. Spraying a thin water-based film on the belt prevents sticking and costs about 1/20th as much as the Teflon.

All the major potato companies use the technology, though not in all their plants and all the places we’d like. We have to prove the technology at every single plant, and it’s hard to convince people to change procedures.