Grantee Research Project Results

Final Report: Novel Method for Produce Preservation and Sterilization in Modern Refrigerators

EPA Contract Number: 68HERC24C0020
Title: Novel Method for Produce Preservation and Sterilization in Modern Refrigerators
Investigators: Roesner, Bruce
Small Business: GreenLifeTech Corporation
EPA Contact: Richards, April
Phase: I
Project Period: December 1, 2023 through May 30, 2024
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2024) RFA Text |  Recipients Lists
Research Category: Small Business Innovation Research (SBIR)

Description:

The EPA has identified food wastage as a major environmental problem, and one that is only getting worse. This is a global problem, with an average of 30-40% of material being produced for human consumption spoiling and being wasted. Approximately 300M pounds of food is discarded into landfills each day which creates 6% - 8% of the surface methane. Methane is more than 28 times as potent as carbon dioxide at trapping heat in the atmosphere. Reducing food waste also poses significant cost savings, totaling over $400B dollars per year in the United States alone, and annual global wastage exceeding $2.6T. Furthermore, the increasing world population is reliant on a shrinking amount of agriculturally viable land for food. Reports show that in the United States alone, over 11 million acres of farmland have been lost in the last 20 years. At the same time, we waste “22% of our fresh water and 16% of our cropland used to produce this wasted food”. This lack of available land, coupled with a drastic increase in population is putting an incredible strain on our agricultural resources and production capabilities. To compound these problems, the way we store our food is antiquated and inefficient. Equally important to increased agricultural yields, advancements in food storage methods must be made in order to feed our population and save our environment.

The chemical process that causes fruits and vegetables to ripen requires inputs of ethylene (produced by the produce) and oxygen that is present in our atmosphere. This reaction then produces carbon dioxide and water. GreenLifeTech™ uses a simple, safe, and scalable patent pending technology to eliminate atmospheric oxygen, resulting in an inert environment to deliver a new and economical means of extending the consumable life of fresh produce up to 500%, using no harmful chemicals or needing any replacement parts, applicable across the entire food chains of farm harvest, distribution, commercial and household, to reduce waste. Oxygen concentrations are reduced to 1-2%, drastically slowing the ripening process.

Fruits and vegetables are also susceptible to pathogen and mold growth, causing faster rates of decay and increasing the potential for sickness when consumed. GreenLifeTech™ has developed a secondary, patent pending, ozone generation technique to work in conjunction with our oxygen removal technology. According to the Centers for Disease Control and Prevention (CDC), an estimated 1 in 6 Americans (48 million people) will get sick from foodborne diseases each year. Of these 48 million people, 128,000 are hospitalized and 3,000 die from these types of infections.

The overall objective of this project was to test and demonstrate the feasibility of integrating the proprietary GreenLifeTech^TM technologies into home refrigerators. To do this, testing on both the oxygen reduction and ozone generation techniques was carried out at GreenLifeTech’s facility, the Purdue University Food Entrepreneurship and Manufacturing Institute, and a potential household refrigeration OEM partner. These techniques would need to be validated using a variety of different produce varieties. Studies were designed to test both sensory features (photographic, willingness to consume) and microorganism growth and propagation. As this is a baseline study for Phase 1, our goal was to show a noticeable benefit from our system, validating the need for further research and development during a subsequent Phase II contract and beyond.

Summary/Accomplishments (Outputs/Outcomes):

Throughout the course of this project, testing has been done at the three locations described above. Evaluation systems were designed and assembled that allow the user to lower oxygen levels in 2-liter containers to 1-2% in about 5-10 minutes. These containers, filled with various kinds of produce, were then placed in refrigeration units at temperatures of 35-37 degrees. The effects of storing produce in a reduced oxygen environment and a low concentration of ozone, only a reduced oxygen environment, and a control group were examined and compared.

Testing at GreenLifeTech’s facility was heavily focused on sensory data and the ripening/decay of produce. Findings showed an overall improvement in the storage life of all produce varieties when stored in a reduced oxygen environment. Blueberries, when stored in the control environment, were not edible after 16 days. However, those stored in our reduced oxygen environment remained edible and mold free out to 53 days. Tests on lettuce also showed excellent results, with produce stored in the reduced oxygen environment showing very little wilting or decay at 18 days. A drastic improvement over the control, which showed heavy wilting at day 8.

Testing at Purdue University examined both sensory elements of the produce storage and  bacterial/mold growth in the ozone enriched environment. While sensory data was positive, the use of ozone for sterilization did not yield conclusive results. It is believed that this was due to an incorrect dosage of ozone. When the dosage of ozone was increased toward the end of this contract, improved results were seen. It should be noted that this new dosage is still very low and safe for the consumer. Further testing to determine the efficacy of this technique will be conducted in the future.

Testing at a potential refrigeration OEM partner was focused on the storage of lettuce. When placed in the reduced oxygen environment, the lettuce was far less wilted and showed little sign of decay at 15 days. Further discussions and testing are ongoing at this facility.

Conclusions:

The research conducted as a part of this contract definitively shows that when stored in a reduced oxygen environment, the shelf life of produce is increased. The GreenLifeTech^TM system provides a cost-efficient, environmentally friendly, and non time consuming method to achieve these low oxygen concentrations. Through discussions with potential household refrigeration partners, we are in agreement that this technology has a logical application in modern crisper drawers. We see this as a game changing improvement to a refrigeration market that has seen remarkably little advancement in food waste reduction technology over the past 20 years.

Though initial ozone testing using low concentrations of ozone (<1.5%) did not yield conclusive results, favorable data was seen when the dosage was increased (5%) at the later stages of this project. This dosage showed signs of both slowing and eliminating mold growth on various varieties of produce. We plan to continue this research in the future until a correct dosage is achieved to reduce the risk of pathogen growth in crisper drawers and beyond.

One of the major problems associated with the household storage of fresh fruits and vegetables is a lack of knowledge on the part of the consumer. Many Americans have heard sayings like “never store Bananas with other fruits” or “One bad apple can ruin the whole bunch.” These are wholly true statements and rooted in ethylene production rates. Modern refrigerators generally have one or two crisper drawers that are intended for produce storage. Inevitably, consumers place many different varieties of fruits and vegetables into each drawer. These varieties produce ethylene at different rates and accelerate the ripening process for each stored item. The crisper drawer is effective in the control of humidity. While this will slightly increase the shelf life of produce, it does little to control ethylene production.

Our system will reduce ethylene production rates and allow for the storage of many varieties of produce within the same drawer. Furthermore, this system requires very little of the consumer. One can simply open the crisper drawer, place produce inside, and then close the drawer. The proprietary GreenLifeTech^TM system is fully automated and will start working at a set time interval after the crisper drawer is closed. We also envision a set interval to recharge the ozone and filter out any residual gasses which may be present. Running the system at this set interval will be possible when placed on a stationary unit, such as a household refrigerator. The system also requires little outside input, running on pennies per day worth of electricity and requiring a filter change only every 10-20+ years.

The market to be served by implementing GLT’s technology in consumer refrigerators is quite large. According to Statista, the number of refrigerators sold annually is more than 215 million, representing sales of more than $125 billion. As there have been no major enhancements in refrigerators in more than 20 years, the GLT technology will be revolutionary to the consumer refrigerator market and a welcome addition. GreenLifeTech has engaged with multiple potential OEM partners during the duration of this project, with discussions ongoing. Initial testing has shown a positive effect of using our technology within their systems, and integration into crisper drawers seems to be an excellent application. Working together with the refrigerator OEMs in this early stage will also reduce the time to market for the final implementation. In summary, this early joint operation will help to define the final product and marketize the technology sooner.

SBIR Phase II:

Novel Method for Produce Preservation and Sterilization in Modern Refrigerators