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'Extra virgin' olive oil: What is it and why does it matter?

Dipping fresh bread into olive oil has become a popular alternative to coating it with butter. Olive oil consists of 85 percent unsaturated fats, and when substituted for saturated fat in the diet can promote ”good” cholesterol (high density lipoprotein or HDL), reducing risk of coronary artery disease.

Some olive oils are more beneficial than others. "Extra virgin" olive oil (EVOO), for instance, is extracted from the olive fruit without using heat or chemical solvents. This mechanical process retains the highest amount of natural “phenolic compounds” — antioxidants and anti-inflammatory agents. Such compounds both retard oxidation in the olive oil (keeping it fresh and preventing rancidity) and confer health benefits.

Miller's diagram (above) depicts the fatty acid content of olive oil. PUFA is polyunsaturated fatty acids.


"Antioxidants combat cell and tissue damage due to oxidation, and anti-inflammatory agents reduce inflammation throughout the body. Inflammation can lead to an array of diseases (arthritis, coronary artery disease and more),” said Amy Myrdal Miller, registered dietitian and a program director at The Culinary Institute of America.

When oils are 'refined,' heat or chemical solvents strip away phenolic compounds; the result is often a bland flavor. Mechanically extracted "extra-virgin" oils retain aromatic components.  Pungent, peppery and sometimes bitter notes signal that an oil contains phenolics.

The growth of premium olive oil production in California has its roots in 1997, when UC Cooperative Extension Sonoma County Advisor Paul Vossen started the first olive oil taste panel in California to help producers improve oil quality using sensory analysis. (See the January 2011 California Agriculture.)

When it comes to detecting positive and negative attributes of olive oil, human tasters are superior to current chemical analytical methods. Standards to define "extra-virgin" and other grades of oil include both sensory and laboratory measures. The International Olive Council's (IOC) narrow definition specifies that EVOO must show no evidence of heat or chemical solvents. It must have zero median "defects" (as judged by trained taste panels) and more than zero median fruitiness. It must meet requirements for low levels of free fatty acids (too many of these signal degradation) and peroxide levels (a sign of oxidation).

This definition has been adopted by the U.S. Department of Agriculture (USDA) and the states of California, Connecticut and Oregon. Beginning on Oct. 24 of 2010, it became part of new USDA standards for olive oil labeling, which also define "U.S. Virgin,"  "U.S. Refined" and other grades.  Although the standards are voluntary, any manufacturer using this terminology on its label could be held to truth-in-labeling laws.

While the ultimate impact of the new USDA standards will take time, consumers can learn to identify flavor attributes of California olive oils by participating in tastings at vendors that feature artisan products. Also, the

California Olive Oil Council awards an extra-virgin certification seal to member oils that are defect-free.

However, the array of olive oils now available at supermarkets can be daunting, and "extra virgin" on the label can be misleading. The UC Davis Olive Center reported in July 2010 that their samples from Sacramento, San Francisco and Los Angeles supermarkets revealed 69 percent of imported EVOO and 10 percent of California olive oil samples labeled as EVOO failed to meet International Olive Council (IOC)/USDA sensory standards for extra virgin olive oil.

Once you identify your favorite olive oil, it should be stored in a cool, dark environment, like a kitchen cabinet removed from the stove, according to Alexandra Vicenik Devarenne, freelance olive oil consultant in Sonoma County. Fluctuations in temperature and light affect the integrity of the health-promoting phenols in extra virgin olive oil.

“When people find out about phenolics and the effects of heat on olive oil, they may question whether it is safe and okay to cook with extra virgin olive oil,” she says. “The heat will destroy some of the health-promoting phenols in the oil, which will change the flavor. The longer the oil is exposed to heat, and the higher the heat, the more phenols will be destroyed.

“However, sautéing in extra virgin olive oil for 5 to 10 minutes over medium heat will have minimal effects on phenols and flavor.”


See more tips on storing and cooking with olive oil.







Posted on Tuesday, November 23, 2010 at 5:10 PM
  • Author: Janet L. White

A feast grows in Baldwin Park

The Baldwin Park Community Garden sits in the shadow of the San Bernardino Freeway in Eastern Los Angeles County. As the cars rush by, an effective and innovative community garden grows. A unique public-private partnership has made this garden possible to benefit the community and local children.

The garden, which is approximately a quarter acre in size, has both school and community plots. The land and financial support are provided by Kaiser Permanente. The City of Baldwin Park helps to maintain the garden. The Baldwin Park Unified School District uses the garden to engage fourth graders from four classrooms at two elementary schools in hands-on nutrition education through a project called “The Moveable Feast.”

The Moveable Feast conducts in-garden nutrition lessons, each of which includes an easy, healthy recipe using garden produce. Each month’s nutrition lesson ties into cultural and community awareness. For example, as the recession deepened, Moveable Feast Director Linda Hahn wanted lessons to tie in with the growing problem of hunger in the community.  She had students prepare two “Rainbow Pita Pocket Sandwiches,” one for themselves, and one for a person in need. Hahn worked with the local food bank to distribute the extra sandwiches.

The garden activities have had a measurable impact on the kids. A survey of the students suggested that 87 percent eat more fruits and vegetables after having participated in the garden.

We receive many requests from teachers, community members and others who are interested in starting gardens. Our Common Ground Garden Program at UC Cooperative Extension in Los Angeles provides printed resources, and sometimes the support of UC Master Gardener volunteers.

Over the years, we've seen many projects succeed, and also many projects that come and go. The Baldwin Park Garden is a great example and seems to have three key ingredients that help to ensure and sustain its success:

  1. Institutional support. Three entities, Kaiser Permanente, the City of Baldwin Park, and the Baldwin Park Unified School District are deeply invested in this project, and support it either financially or through significant in-kind contributions.

  2. Meaningful youth involvement. Teachers and the school district, via the Moveable Feast, engage children in effective, measurable garden-based learning that’s tailored to the needs of the community.

  3. Promotion of the project to the community and key decision makers. The Moveable Feast has a “Guest Chef” program that brings in local leaders to see and participate in the garden. Student essay competitions, a garden cookbook and thank-you celebrations also help to promote and further engage the community in this endeavor.

For the kids, its success is very simple. As one student stated, "The garden is the best place I have gone since I entered fourth grade. It is the best garden in the world."

A fourth-grade student reads her winning garden essay as Linda Hahn looks on.
A fourth-grade student reads her winning garden essay as Linda Hahn looks on.

Posted on Friday, November 19, 2010 at 12:23 PM

Grant High School grows food and leadership

Recently, UC’s Agricultural Sustainability Institute gave me the opportunity to visit Grant Union High School in Sacramento to learn about their GEO Environmental and Design Academy, which includes a gardening and cooking program.

The school is in an economically challenged area, and about half the students are English language learners.

Teacher Ann Marie Kennedy said something interesting about the students enrolled in the program: “They are disconnected from agriculture, but they are not disconnected from food.”

The Grant garden is essentially a shared school and community garden, which I believe is one of the best models for school garden sustainability. Community gardeners have individual plots, but assist in the school garden areas. Some of the community gardeners have children or grandchildren enrolled at Grant, but others are connected to the school simply through their love of gardening and the opportunity to cultivate food.

During our visit, we worked alongside the students to harvest, wash and chop vegetables to make chicken and vegetable chow mein and garden-fresh salad for lunch. We also sampled Grant’s salsa, which is sold commercially, providing a real-life business incubator for seniors in the program.

The lunch was simple ... and simply amazing. Not only the food, but the chance to speak with students and learn about how the program has influenced their lives. The students said they are eating more fruits and vegetables and bringing the practice home to their families.

I ended my visit with enormous gratitude for the work of Grant Union High staff and profound awe for the students. I have a great deal of confidence in a future that includes their leadership.

But I also left with the idea that this exceptional program should not be the exception, but rather, the norm. If we are truly committed to a healthy future and a healthy nation, we need programs like this, that provide opportunities for youth engagement with soil, healthy food and mentors who will encourage their leadership abilities.

Posted on Wednesday, November 17, 2010 at 7:28 AM

UC scientist says transgenic salmon is safe

The U.S. Food and Drug Administration is considering approval of genetically engineered salmon developed by AquaBounty Technologies, a Massachusetts biotechnology company focused on improving productivity in commercial aquaculture.

Paul Olin of the California Sea Grant Extension Program says the transgenic salmon is safe for consumption and the environment.

"If we take time to learn the facts and understand the science we can all appreciate new advances in our ability to produce healthy, sustainable food with the confidence that it has been vetted by the scrutiny of the world’s best science," Olin said.

The “AquAdvantage” Atlantic salmon (AAS) has two genes that considerably hasten its growth, one from Chinook salmon and the other from ocean pout. AAS reaches market size twice as fast as traditional salmon, providing an economic benefit to farmers and enhancing the economic viability of inland operations, thereby diminishing the need for ocean pens.

AquaBounty plans to grow the hybrid fish on Prince Edward Island, ship small fish to inland recirculating production systems in Panama, harvest and process the fish, and ship food grade product back to the United States for sale. The fish for this production system would be 95 percent triploid females, as a duplicative measure to prevent reproduction. Olin said triploid crops have an extra set of genes and are widely used in agriculture including such apple varieties as Gravenstein and MacIntosh, and seedless bananas, watermelon and grapes.

Olin cited a 2008 scientific review, published in the Journal of the Royal Society of Medicine, that said GM foods had been eaten by millions of people worldwide for 15 years, with no reports of ill effects.

"New technologies to genetically improve food and animal crops are one tool to supply the additional food people will need in the future, improving human health, reducing the use of pesticides and fertilizers, and reducing the carbon footprint of animal and plant agriculture," Olin said.

AqaAdvantage Salmon
AqaAdvantage Salmon

Size comparison of an AquAdvantage® Salmon (background) vs. a non-transgenic Atlantic salmon sibling (foreground) of the same age.

Posted on Monday, November 15, 2010 at 11:19 AM

Local farms please new moms and kids

You may have noticed changes lately in some little food stores tucked into your neighborhood strip mall or main street, stores with names like "Prime Time Nutrition" or "Fiesta Nutrition." These stores are now offering enticing displays of fresh fruits and vegetables along with the infant formula, breakfast cereal, eggs, cheese and other foods that have been offered to mothers, infants and children through the WIC program since 1972.

The UC Small Farm Program and Cooperative Extension advisors in three California counties are piloting a new "Farm to WIC Program" with the stores to make sure that some of the fresh produce on the shelves comes directly from small-scale local growers, helping low-income families to participate in USDA's "Know Your Farmer, Know Your Food" campaign.

The mission of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is to safeguard the health of low-income women, infants and children up to age 5 who are at nutrition risk. The program provides nutritional education and vouchers for supplemental foods to qualifying families. By 2002 almost half of the infants and about one quarter of children ages 1 to 4 in the country participated. The vouchers can be redeemed at most large grocery stores, but many WIC participants prefer to shop with their vouchers at the small, privately-owned WIC-only stores that have sprung up since 2000, carrying only WIC foods and catering primarily to WIC participants.

In October 2009, the WIC program began including vouchers for fresh fruits and vegetables in the monthly allotment to all participating families. This addition meant that all WIC-authorized retailers had to begin offering a variety of fresh fruits and vegetables to their customers - no problem for traditional supermarkets, but a big change for the smaller WIC-only stores. All of a sudden they were in a new business, the produce business. The store owners now have to understand their customers' fresh produce preferences as well as safe handling of perishable products that don't arrive in the store with "sell-by" dates stamped on them.

With funding from the California Department of Food and Agriculture's Specialty Crops Block Grant program, a team of UC Cooperative Extension specialists and advisors are partnering with WIC-only stores to ease this transition.

The nutrition advisor team, led by UCCE specialist Lucia Kaiser, first conducted a survey of WIC participants at WIC clinics in Alameda, Tulare and Riverside counties to determine what crops the women would like to purchase and what qualities were most important to them in deciding what to buy. Using this information, farm advisors in each county, led by UC Small Farm Program director Shermain Hardesty, introduced local growers who could supply the selected crops in season to WIC-only store owners at stores popular with WIC participants. Soon, staff in the stores will participate in post-harvest handling training sessions led by UCCE specialist Marita Cantwell and will each receive colorful posters and handouts to help their customers select, prepare and store the fresh produce.

Lessons learned from this UC pilot project will help connect local small-scale fruit and vegetable growers with WIC retailers and keep the best local fruits and vegetables available to WIC families throughout California.

Posted on Thursday, November 11, 2010 at 1:33 PM

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