A University of Massachusetts – Amherst food scientist has been awarded a U.S. Department of Agriculture (USDA) grant to develop an oil-based system to clean and sanitize food processing equipment without water, reducing the risk of Salmonella contamination associated with nuts.

Lynne McLandsborough’s $434,215 grant was one of 19 food safety and defense grants totaling $8 million announced by the USDA’s National Institute of Food and Agriculture.

“Cleaning commercial peanut butter and other nut paste facilities is especially challenging,” McLandsborough says, “since the presence of liquid in the processing environment can promote growth and survival of microorganisms. It is well-established that peanuts and tree nuts are high-risk foods concerning Salmonella contamination, due to the multiple major outbreaks associated with commercially produced peanut butter.”

The overall goal of this study is to develop and validate oil-based antimicrobial delivery systems for dry cleaning and sanitation of food processing equipment. According to the submitted hypothesis, an oil-based delivery system will be an effective means to deliver antimicrobial organic acids and essential oils to non-growing bacteria for clean-in-place applications. The objectives are as follows:

1. Develop and test oil-based antimicrobials to destroy bacteria non-water based (dry) cleaning and sanitation of food processing equipment. A rapid screening method will be developed to screen desiccated cells against the formulated oil-based antimicrobial solutions. Oil-based antimicrobial solutions will be formulated with organic acids delivery or water-in-oil emulsions containing traditional sanitizing agents.
2. Validate the effectiveness of oil-based antimicrobials in a bench-top clean-in-place system. A bench-top clean-in-place system will be developed to evaluate the efficacy of the developed oil-based antimicrobials against Salmonella in the presence of peanut butter.
3. Investigate the mechanisms of oil-based antimicrobials. Microscopy will be used with a combination of fluorescent stains to assess the influence of oil-based antimicrobials on membrane disruption, cellular respiration, protein translation, and membrane viscosity.

From the food industry’s perspective, McLandsborough’s novel approach to sanitizing peanut butter processing plants with cleaning oils would offer several benefits. The factories could be more easily, safely, and quickly cleaned with oil-based solutions than with water-based agents, which currently require a plant shutdown for nearly a week to carry out cleaning.

“The long-term impact of the proposed research is the high potential for translation of the technology to the food industry, which has a high need for non-water-based cleaning,” she says.

Researchers aim both to develop and validate the effectiveness of innovative technologies for non-aqueous cleaning and sanitizing, focusing on combining a variety of organic acids to create oil-based antimicrobial solutions.