The Brown Effect
Professor Wyatt Brown and his team in the Horticulture and Crop Science Department in the College of Agriculture, Food and Environmental Sciences developed a cutting-edge formula to prevent the premature browning of fresh-cut fruits and vegetables. What makes this formula especially valuable is that it also reduces the growth of aerobic bacteria, yeasts and molds on these products, making them safer to eat.
Cal Poly was granted a U.S. patent for the formula in June 2015 and is actively seeking licensees to commercialize it. The university is in discussions with several large companies interested in the formula, Brown said.
“We don’t want to sell its use to one single company,” Brown said. “We want this Cal Poly formula to be as widely available as possible.”
Brown and his team conducted more than 400 tests over four years to create the formula. Brown and laboratory technician Jim Green tested more than 40 compounds on apple slices to determine what worked and what didn’t.
“Part of the process was running into dead ends,” said Brown. “For example, oxalic acid worked great, but the Federal Drug Administration (FDA) doesn’t approve of its use on fresh-cut products.”
Several students, excited by the prospect of the research, volunteered to help in the lab. “This is real science, in real time,” Brown said. “This is not doing a project for the sake of doing a project.”
Justin Borba, an agricultural and environmental plant sciences major who is considering a career in postharvest technology, worked in the lab during the spring quarter.
“I was able to use observational analysis to see all the little details that are largely unnoticed in grocery stores or restaurants,” said Borba. “Learning the basics of lab work and assisting with research was an awesome opportunity.”
Brown was careful to avoid using compounds that could cause an allergic reaction, such as sulfur. After years of laboratory work, the solution was found, extending the shelf life of certain pre-cut foods by up to two weeks longer than the current anti-browning formula on the market. In addition, the formula is effective under ambient conditions; special packaging is not required.
“We wanted to make sure that what we used was safe,” Brown said. “Everything we used in the final formula has already been pre-approved as safe by the FDA.”
The anti-browning formula combines calcium ascorbate, calcium propionate and calcium chloride in precise ratios, and the ratios are product-dependent.
When applied to pre-cut Granny Smith and Fuji apples, the formula prevented browning and the growth of aerobic bacteria, yeasts and molds for at least 21 days. It has also proven to be highly effective at preventing the browning of other sliced fruits and such as pineapple.
“We believe the formula will enable products to be marketed for a longer period of time and help reduce the incidence of food-borne illness,” Brown said.