What makes food nutritious?

May 10, 2010

Workers sort tomatoes at Russell Ranch
Workers sort tomatoes at Russell Ranch

Part of our mission at the Agricultural Sustainability Institute at UC Davis is to ensure access to healthy food. So we’ve focused much of our work on the intersection between agriculture and human nutrition.

An interesting new field of study in this area looks at flavonoids, which are compounds in fruits and vegetables thought to have beneficial antioxidant effects and other medicinal value – they may even help reduce cancer risk.
Measuring the amount of flavonoids is one way we can figure out just how nutritious the food we’re eating really is.

At our Russell Ranch Sustainable Agriculture Facility, UC Davis Food Science professor Alyson Mitchell has looked at the relative nutrition of organic and conventional tomatoes by measuring flavonoid levels in samples from dried tomatoes over a 10-year period.

AerialViewCIFS
Aerial view of Russell Ranch Sustainable Agriculture Facility

She found that flavonoid content is greater in organic than conventional tomatoes, and the differences have increased with time. Over time, it also appears that an increase in flavonoid content is correlated with lower amounts of organic nitrogen application.

These results suggest that over-fertilization can result in lower flavonoid content – and a reduction in the health benefits of tomatoes. You can find out more about this research here.


By Colin Bishop
Author - Communications and Outreach | Packard Fellow