Innovative Solutions For Food Waste Handling At The Food Service Level

A particularly bad example of leftover food after a meal at a restaurant.

Waste is a practical challenge throughout the food chain all the way from the farm to the consumer. A substantial amount of waste occurs at the food service level because it isn't possible to fully predict what will be ordered from the menu on any given day and because not all customers will eat their entire portion. The worst case scenario is that food waste and other organic matter ends up in a landfill where it may be converted to the potent greenhouse gas, methane. The EPA states "methane is 25 more times potent as carbon dioxide at trapping heat in the atmosphere. Over the last two centuries, methane concentrations in the atmosphere have more than doubled, largely due to human-related activities."

There are programs such as one called Feeding San Diego in which unsold food from Starbucks SBUX stores is collected and used to feed the hungry. Not all surplus prepared food can be handled that way and discarded food is still problematic as are the normal trimmings, peels and other organic materials generated in the process of food preparation. Some states such as California are making a concerted effort to divert this waste stream to composting facilities, but that option has several drawbacks. While the waste is waiting for standard collection methods it can generate odors and attract pests like fruit flies and rats. Most composting facilities and systems are designed to handle yard and landscape waste and restaurant waste can be problematic and can also end up being at least partially converted to methane in that setting. Fortunately, there are several innovative strategies which offer practical solutions for waste at the food service level.

One comes from a company called Hungry Giant whose technology is based on is bio-dehydration. Food waste tends to have a very high moisture content, so by grinding and drying the waste-it can rapidly be reduced in volume therefore becoming a smaller burden with more flexible options for further reuse. Chris O’Brien is an entrepreneur who had become interested in waste disposal issues early in his career, always seeking practical solutions to real world problems. O’Brien started his company with the idea of bringing to market a full range of ruggedized machines to tackle commercial food waste. Today they have a full range of grinding, and vacuum transfer systems to automate the whole process of handling food waste. The output has various applications other than just compost amendment. It has zero solids or sludge that go down the drain, potentially clogging plumbing and increasing grease trap removal costs. Some customers (like cruise lines) use it to offset energy requirement (energy from waste), some turn it into products such as pet food and others make a soil amendment as it does retain good nutrients. Because it's biologically stabilized - it doesn't house microbes or pose any pathogenic risk.

Hungry Giant CEO Chris O'Brien and a larger scale bio-dehydrator unit at a composting facility in ... [+] Austin

These restaurant scale units do require phase three power, but that is commonly available in restaurants. They use heat through recirculated hot air, an impeller, thermostatically controlled heating oil jacket, and a steam point condenser that can reduce the waste volume by 70 to 93%. No microbes survive the process (above thermophilic thresholds) so it doesn't have the typical odor. and pest issues that rotting food waste has while waiting for pickup. It can be stored for extended periods of time, therefore less pick-ups and less emissions. O’Brien's company expanded into the US in 2012. Chris moved to Austin TX in 2018 to continue growing the company. The company has averaged 300% growth over the last 3 years.

Another technology for restaurant level waste traces back to South Korea. Alan Pressman came from a trading and merchandizing background but became interested in methane emission solutions after seeing a dramatic visual of that phenomenon on a segment of 60-Minutes. Later he had coffee with an old college friend after 30 years apart and he told him about a system sold by a company called ExBio in South Korea that creates a warm temperature controlled environment with plenty of oxygen in which a proprietary consortium of microorganisms are able to digest the waste into a form that can easily go down the drain to the sewer as "grey water."

An ExBio digester unit

Some wastes are digested within three hours but by 24 hours just about anything will disappear. Even crab and lobster shells, and small beef and chicken bones can be processed this way. Pressman and his associate have partnered with the company in South Korea and market this technology globally. Restaurants that employ this technology typically save enough on waste hauling fees to pay for this system within three years. The organisms that make the enzymes that do the work are refreshed every 6 months and the company continues to refine that mixture.

Many modern restaurants and other food service sites use disposable plates, cups, utensils and straws. This reduces the amount of water and energy that would have been used for washing, but it does generate a large volume of waste. There is a Georgia-based company called WinCup that was established in 1962 which supplies disposable containers and implements to many customers in the institutional food service business. Four years ago, the company made the decision to focus on sustainable solutions and has grown into the largest US supplier of bio-based alternatives to traditional products like foam cups, lids, straws etc.

Phade® straws made from the biopolymer PHA are compostable and can also be processed in the Hungry ... [+] Giant bio dehydrator system

Much of the company's recent growth is the result of Phade® straws which are made with the biopolymer PHA (polyhydroxyalkanoate – NODAX DAX ™from Danimer Scientific). Unlike many bio-based materials such as PLA (polylactic acid) that are only theoretically "compostable," Phade® straws have been certified as truly compostable in home and industrial systems and its resin has been certified for marine biodegradability. A timelapse film of the process in salt water is posted here. The straws can also be handled in the Hungry Giant systems described above. One billion Phade®straws have sold. In 2020, WinCup was acquired by the sustainability-oriented investment group Atar Capital. The company also develops Vio, the first biodegradable foam cup in the US.

There are other potential options for food service level waste including anaerobic digestion to generate renewable natural gas. That option is limited for this application because it is quite capital intensive. There is also the possibility of feeding the food waste to certain insects and then turning those into a protein-rich animal feed. The bottom line is that there are several viable alternatives to composting for dealing with these particular organic waste-streams.