Email Print Site Map
UC Food Safety
University of California
UC Food Safety

UC Food Blog

I say tomato!

Here we are, a month into summer, and one of my favorite fruits is starting to emerge: Luscious tomatoes, fresh off the vine.

I know, most of us treat tomatoes like a vegetable in the kitchen, slicing and dicing them into dishes that are savory rather than sweet. Botanically speaking, tomato is a fruit because it’s developed from the ovary in the base of the flowers and contains the seeds of the plant (though cultivated forms may be seedless.)

No matter, the tomato is a nutritional powerhouse any way you cut it, loaded with vitamin C, vitamin A, potassium and lycopene, an antioxidant credited with preventing both cancer and heart disease.

The UC Davis Department of Plant Sciences devotes many resources to tomato production, helping large- and small-scale growers, organic and otherwise, control weeds, manage pests, fight disease and tackle all the other adventures farming can bring. The department is also home to the C.M. Rick Tomato Genetic Resource Center, the largest known collection of tomato seeds in the world. You can’t breed a better tomato without diversity of genetic tissues, and the repository and its abundance of wild species are the sources of resistance to 44 major tomato diseases and at least 20 insect pets – not to mention improved fruit traits like tolerance to saline conditions and drought.

Of course, growing or buying a tomato is only part of the equation. How do you make sure the fruit of your labor is tasty and safe? Here are some helpful hints from the UC Davis Postharvest Technology Center, a handy resource for all your postharvest technology needs:

How to choose: A ripe tomato will be plump, vibrant in color and fairly firm to the touch. You want it to have a little give, but not much. Ageism aside, avoid a tomato with wrinkles.

How to store: Keep tomatoes at room temperature, away from direct sunlight, with the stem scar (the belly button, if you will) facing up to reduce softening and darkening of the fruit. It’s best to eat them within two or three days, though some tomatoes are perfectly fine for about five days. Store tomatoes unwashed and then rinse them under running water before eating.

How to prepare: After rinsing your tomato well, wipe it dry and cut away the stem scar and surrounding area before slicing into it. Don’t wash tomatoes in a sink filled with water (nor use soap or detergent) because tomatoes can absorb contaminated water and soap residue through its stem scar. Cut or chopped tomatoes (and dishes like salsa) should always be covered and refrigerated if not consumed within two hours or preparation. Cut tomatoes will last one or two days in the refrigerator.

How to enjoy: Enjoy them every which way! It would be hard pick my favorite tomato recipe, but you can’t go wrong with this fast, fresh salad:

Tomato platter special

Four fresh tomatoes of any color or variety
Two red onions
Two orange, yellow or red bell peppers
A few sprigs of basil
Your favorite vinaigrette
Four ounces Feta cheese

Slice the produce into circles and fan them out on a platter in an attractive, alternating order. If you have fresh cucumbers, they fit nicely in this flower, as well. Drizzle with vinaigrette, crumble on some Feta cheese, give a few grinds of fresh pepper and few shakes of salt and place basil sprigs on top.


You can read more tomato tips from the Postharvest Technology Center here and explore many more of their practical publications here.

Posted on Tuesday, July 26, 2011 at 8:13 AM

There's a new avocado in town

GEM avocado.

The UC Riverside avocado breeding program has identified a promising new avocado variety, which scientists believe will soon take off commercially.

The GEM avocado is the great-granddaughter of Hass avocado, which is currently the industry standard in California. GEM has all the excellent characteristics of Hass avocados - creamy, nutty flesh; dark, pebbly skin when ripe - and it has additional benefits for the grower, according to Mary Lu Arpaia, a UC Cooperative Extension subtropical horticulturist based at the UC Kearney Agricultural Research and Extension Center in Parlier, Calif.

"Hass avocados are alternate bearing - they will produce a big crop one year, and a small crop the next. GEM is more consistent, so growers can make money every year," Arpaia said. "The trees are also more compact, which means growers have less costs for harvesting and tree maintenance."

GEM was part of an extensive avocado variety breeding program led since the 1950s by UC Riverside plant breeder Bob Bergh. Arpaia took over the program in 1996.

In the early 1980s, Bergh released a variety he called the Gwen. However, Gwen didn't turn black when it ripened, a disadvantage because consumers are accustomed to Hass. In the mid 80s, Bergh planted more than 60,000 avocado variety seedlings on farms across Southern California. GEM, a daughter of Gwen, was one.

There are GEM trees growing at the UC South Coast Research and Extension Center in Irvine. Fruit samples are sent to the Kearney Sensory Laboratory, where volunteers judge the fruit's outward appearance and compare the flavor with Hass.

Recently, UC Riverside signed an exclusive license agreement with Westfalia Fruit Estates, a South African company, to market GEM around the world, the university announced. In the United States, the California–based Brokaw Nursery has non-exclusive rights to the GEM avocado.

For information on GEM avocado sensory testing, see the one-minute video below.

Read a transcript of the video.

Posted on Thursday, July 21, 2011 at 7:47 AM

Proper nutrition can prevent negative health outcomes in young female athletes

Since the onset of Title IX in 1972, opportunities have dramatically increased for female athletes, largely to their benefit. However, some negative health outcomes such as disordered eating, chronic menstrual disturbances and low bone mass have been associated with high-level competition among some female athletes, particularly in sports such as gymnastics and cross-country running, where a slender physique or lean body build is important.

“Adolescent female athletes, in a rapid growth and development phase, may be at greatest risk,” authors Michelle T. Barrack of UCLA and Marta D. Van Loan of the USDA Agriculture Research Service report in the July-September 2011 issue of California Agriculture journal. Their review article is published in a special issue of the journal, “Food as medicine: Can what we eat help cure what ails us?”

The article identifies athletes at risk in order to understand the origin of possible negative outcomes and recommend behavioral modifications that promote participation in competitive sports while supporting lifetime health.

The “Female Athlete Triad syndrome” is a trio of interlinked negative outcomes that can result from poor nutrition in a small percentage of high-level female athletes:

  1. Low bone mass in young women can lead to the early onset of osteoporosis and increased risked for bone fractures;

  2. Menstrual disturbances are caused by inadequate reproductive hormones, especially estrogen, which can in turn inhibit bone mineralization during adolescence and impede bone maintenance thereafter;

  3. Eating disorders can disrupt the menstrual cycle, resulting in low or no estrogen production; adequate levels of estrogen are needed to increase bone mineralization and, in turn, bone density.

An important question is whether these exercise-related health problems occur from an energy deficit, in which calories consumed do not meet calories needed for the increased level of physical activity, or from excess stress that alters the hormones regulating menstrual function and bone metabolism.

“Several well-controlled animal and human experimental studies have confirmed that as long as energy is available for physiological needs other than exercise, it promotes normal hormone function,” Barrack and Van Loan note. “This suggests that intense exercise does not in itself exert an additional stress that disrupts menstruation and bone metabolism.”

The article details the basic nutritional needs of female athletes.

“Just consuming enough energy (calories) is not enough,” Barrack and Van Loan wrote. “For optimal health and peak performance, it is critical to consume the three primary macronutrients for energy metabolism (carbohydrates, protein and fat) as well as a multitude of micronutrients (vitamins and minerals).” Critical micronutrients include B vitamins, antioxidants, calcium and vitamin D, iron, zinc and magnesium.

“The optimal diet for a young, developing athlete should maximize sport performance, while reducing injury risk and facilitating overall health, growth and maturation,” the authors wrote. “Due to the metabolic and physiologic demands of their sports, the nutrient needs of young athletes can be much higher than their nonathlete peers and higher than the needs of young adult athletes who have reached maturity. It is important to make competitive adolescent athletes aware of their specific needs as well as to identify those athletes at risk of developing deficiencies.”

Posted on Wednesday, July 20, 2011 at 7:12 PM
  • Posted By: Janet Byron
  • Written by: Janet Byron

Gardening towards self-sufficiency

In hard times, Americans have always turned to gardening.  Gardens enable people to improve their food security. Plus gardens have many other benefits.

The Victory Gardens of World War I and World War II - and the garden efforts of the Great Depression - helped Americans increase home and community food security. In addition to helping the family budget and improving nutrition, these gardens helped to save fuel by reducing transportation; provided natural beauty in communities; empowered every citizen to contribute to a national effort; and bridged social, ethnic, class, age and cultural differences during times when cooperation was vital.

We are in the midst of a new cycle of a garden movement. While there are many reasons people are gardening today, there is a growing demand for food that is tasty, nutritious, and economically and environmentally sustainable.

The current resurgence in home and community gardens is similar to previous calls to garden in our country. Using gardens and the food that comes from them, we can profoundly change our lives and our communities. Gardening empowers eaters to take an active role in producing their own food. This simple act can improve nutrition, teach youth about science, reduce health care costs, regenerate the economy, preserve natural resources, strengthen national security, build resilient communities and nourish future generations.

Gardening offers many opportunities to improve one’s life by providing outdoor exercise, and excellent nutrition with home-grown fruits and vegetables. Working outside at home makes it easier to meet and greet neighbors – or make new friends at a community garden. But perhaps most importantly, during these uncertain economic times, gardening can help people be more self-sufficient.

The University of California has many resources for people and communities interested in gardening. The UC ANR Free Publications website and the UC ANR Catalog, which contains both free and priced publications, are great places to start.


Gardens provide many benefits to individuals, families and communities.
Posted on Thursday, July 14, 2011 at 5:41 AM
  • Author: Chris M. Webb

Enjoy summer’s fruits and vegetables — safely

Now that we’re in the thick of summer and eating bountiful quantities of uncooked fresh fruits and vegetables (salads, and fruit bowls, and tomatoes — oh my!), it’s time to make sure we handle them properly to avoid foodborne illnesses.

According to Dr. Trevlor Suslow, a plant pathologist and Cooperative Extension specialist at UC Davis, “Americans consume more than six billion servings of uncooked fresh fruits and vegetables every year, versus a very small number of illnesses that are clearly linked to foodborne pathogens.”

The take-home message is that the food supply in the U.S. is generally very safe, particularly when everyone in the food supply chain (including consumers) does their part to assure food safety.

The U.S. Food and Drug Administration (FDA) recently released the following information for home consumers:

Nearly 48 million people (1 in 6 people) are sickened by food contaminated with harmful germs each year, and some of the causes might surprise you.

Although most people know animal products must be handled carefully to prevent illness, many don’t realize that produce can also be the culprit in foodborne illness. In recent years, the U.S. has had several outbreaks of illness caused by contaminated fruits and vegetables — including spinach, tomatoes, and lettuce.

Fresh produce can become contaminated in many ways. During the growing phase, fruits and veggies may be contaminated by animals, harmful substances in the soil or water, and poor worker hygiene. After produce is harvested, it passes through many hands, increasing the contamination risk. Contamination can even occur after the produce has been purchased, during food preparation, or through inadequate storage.

The FDA says to choose produce that isn’t bruised or damaged, and make sure that pre-cut items — such as bags of lettuce or watermelon slices — are either refrigerated or on ice both in the store and at home. In addition, follow these recommendations:

  1. Wash your hands for 20 seconds with water and soap before and after preparing fresh produce.
  2. Cut away any damaged or bruised areas before preparing or eating.
  3. Gently rub produce while holding under plain running water. There’s no need to use soap or a produce wash.
  4. Wash produce BEFORE you peel it, so dirt and bacteria aren’t transferred from the knife onto the fruit or vegetable.
  5. Use a clean vegetable brush to scrub firm produce, such as melons and cucumbers.
  6. Dry produce with a clean cloth or paper towel to further reduce bacteria that may be present.
  7. Throw away the outermost leaves of a head of lettuce or cabbage.

Store perishable produce in the refrigerator at 40 degrees or below.

(Condensed from an FDA news release. The site has an interesting video and useful links to other sites with food safety information.)

For more on what UC Davis and UC Cooperative Extension are doing to assure the safety of fresh produce:

Posted on Tuesday, July 12, 2011 at 5:35 PM

First storyPrevious 5 stories  |  Next 5 stories | Last story


Site Creation date 6/1/2009
Webmaster for site:  Zann Gates

Webmaster Email: