No matter how filled fruits and vegetables are with health-promoting and disease-fighting nutrients, they have to make it to market with their nutritional value intact, free of microbial contamination, and looking, smelling, and tasting great.
This is the challenge of postharvest physiologist Penelope Perkins-Veazie, PhD, N.C. State University professor in the Department of Horticultural Science and with the Plants for Human Health Institute (PHHI) at the North Carolina Research Campus (NCRC) in Kannapolis.
“I start working with a crop once it comes in from the field,” Perkins-Veazie said. “I look at how to extend the shelf life or maintain the quality of it. I also look at the changing phytonutrients in the crop itself.”
Muscadine grapes, a mainly Southeastern crop, are grown for juice and wine. Perkins-Veazie is helping growers take advantage of new opportunities to sell in fresh markets. For that to happen, Perkins-Veazie said, there’s a need for a bigger, seedless fruit with a thinner peel.
“That changes everything from a postharvest perspective,” she continued. “You have to change the whole method of thinking, as fresh fruit require very different handling, cooling, and packaging protocols compared to processing fruit. One thing I’m working on is looking at a range of muscadine varieties so we can extend storage time from four weeks to 16 weeks.”
Perkins-Veazie has projects involving vegetables such as lettuce, sweet potato, cucumber, and tomatoes, but she prefers fruits. She collaborates with plant breeders including PHHI researcher Jeremy Pattison on his strawberry research. She also evaluates the quality and phytonutrient changes in raspberries and blackberries, some of which are developed specifically for the North Carolina climates.
Using the expertise and equipment at NCRC, her graduate student found that one of these raspberry varieties exhibits a unique pigment profile, which will be useful in tailoring raspberries for specific dietary targets. Perkins-Veazie has worked with the National Watermelon Board for several years to identify bioactive compounds in watermelon and to find ways to develop value added products.
“There are more than 1,000 varieties of watermelon,” she said, “and we’re trying to find, for instance, the varieties low in sugar and high in lycopene for those with diabetes who love watermelon but can’t eat much of the traditional types, or those richer in Vitamin C or citrulline, an amino acid that helps with vasodilation and may help lower blood pressure.”
Collaborating with the Appalachian State University Human Performance Lab at the NCRC, studies are under way to investigate the potential for watermelon to help athletes recover from strenuous exercise. Another project is the development of new fresh cut watermelon products and identification of unique pigments in orange and yellow fleshed watermelon fruit. She is also looking at watermelon in relation to skin damage.
“We’ve been chipping away for a couple of years looking at watermelon and skin damage,” Perkins-Veazie said. “We know lycopene is very good at blocking UVA and UVB rays, and we know it’s taken up into the skin. Ultimately, we’re interested in trying to demonstrate whether a regular ingestion of watermelon in the diet will reduce sun damage.”
Perkins-Veazie is part of the continuum of research at PHHI that is opening up new opportunities for North Carolina agriculture while ensuring that fruits and vegetables are part of a healthy diet and understood as sources of prevention and possibly treatment of disease.
For more information visit the PHHI website.