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UC Food Safety

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Keeping olives on the table

Table olives have always been a staple on my family’s fall relish tray so I took notice when I heard this discouraging news: Labor costs are killing the table olive industry. Table olive growers spend more than half of their gross returns on the cost of manually harvesting their crop.

“That’s a ridiculous equation,” says Dennis Burreson of Orland, grower and chairman of the research committee of the California Olive Committee. “We can’t survive if we’re spending more than half our gross returns on labor.”

But here’s the heartening news: With the help of UC Cooperative Extension specialist Louise Ferguson (right) and a large group of collaborators, the industry is doing something about it. They are developing the means to mechanize the devilishly difficult task of picking table olives.

“I think mechanical harvesting will soon revolutionize the table olive industry,” said Ferguson, pomologist with the UC Davis Department of Plant Sciences and director of the UC Davis Fruit & Nut Research and Information Center.

Mechanical harvesters are commonplace for countless commodities, including olive oil olives. What is it about table olives that make them so hard to mechanically pick?

They bruise easily, for one thing, and bruised olives don’t cure well. Plus, table olives are harvested while still immature – unlike the more mature olive oil olives – so it takes more force to knock them off the tree. And then there is the tree canopy: Table olives trees tend to be wispy, less accommodating to mechanical harvesting than the high-density hedgerows you see in olive oil orchards.

Visit a typical table olive orchard and you will see the problem. It’s hard for a mechanical shaker to clean fruit off a tree that just sways, especially when that fruit is hard to dislodge in the first place. Plus, olive tree trunks get knobby with age (like the rest of us). If a machine rubs the bark off those knobs, it opens the tree to disease.

Scientists and engineers have been trying for decades to come up with a viable mechanical harvester. As with earlier attempts, a few versions designed and tested in the mid-90s didn’t pan out because they didn’t remove and capture enough high-quality fruit. But more recent efforts are showing great promise.



The two leading picking technologies are “canopy contact harvesting heads” (it resembles a huge hair brush) and trunk shakers. The canopy contact harvester can be used in existing orchards when they are pruned into a hedgerow and can also be used in the new high-density orchard Ferguson and her team designed, modeled after olive oil orchards. The trunk-shaking technology can be used in new high-density orchards but not in conventional orchards.

And here is the good news on fruit quality, the piece of the puzzle that now makes mechanical harvesting so promising: Even trained testers couldn’t tell the difference between manually and mechanically harvested table olives.

“That’s huge because fruit quality had always been a sticking point,” Ferguson says. “Jean-Xavier Guinard (sensory scientist with the UC Davis Food Science and Technology) worked with an expert panel trained to detect even the slightest defect in texture, taste, aroma – the works. They detected virtually no different between olives that were manually and mechanically harvested.”

More taste tests with both expert and consumer panels are in the works. In the meantime, several growers have decided to take the plunge. Burreson, for example, has planted 120 acres of table olives in the high-density hedgerows Ferguson helped design. In about five years, his olives will be ready for harvest.

So keep your fingers crossed as you enjoy your table olives, figuratively if not literally. It’s hard to keep your fingers crossed if eat them the old-school way, one at a time off each finger and thumb.

Posted on Wednesday, October 13, 2010 at 8:54 AM

Nuts contribute protein, fiber and healthy fat to diet

Two free publications on nuts have recently been published by ANR — Nuts:  Safe Methods for Consumers to Handle, Store, and Enjoy and Nuts:  Safe Methods for Home Gardeners to Harvest, Store, and Enjoy.

Both publications outline the nutritional benefits of eating nuts, including information from the FDA affirming that:

  • Including nuts in a diet low in saturated fat and cholesterol may help reduce the risk of heart disease.

  • Almonds, pecans, pistachios, and walnuts contribute to health through their protein, dietary fiber and unsaturated fat.

The consumer publication includes a handy table outlining optimal freezer and refrigerator storage times for a variety of nuts as well information on nut allergies, nutrition and resources for recipes.

Home gardeners with nut trees will find useful information on harvest times and methods, hulling and drying procedures, safe handling procedures, storage, and nutrition information for almonds, chestnuts, pecans, pistachios and walnuts.

Inside both publications is a discussion of recent bacterial outbreaks in nuts and the steps producers have taken to minimize the risk of exposure to consumers.

Posted on Monday, October 11, 2010 at 8:38 AM

President's Blend: Yudof chooses olive oil

Signed, sealed and soon to be delivered: University of California President Mark Yudof’s own blend of olive oil.

UC Davis already has its own popular olive oil, sold in the campus bookstore and online, with customers including Yudof. The self-supporting UC Davis Olive Center – the only academic center of its kind in North America – is looking to branch out with the UC-wide President’s Blend.

A day before Yudof began his tour of high schools to promote access to a UC education, he visited the UC Davis Olive Center on Sept. 30 to give his official seal of approval to the President’s Blend olive oil.

Accompanied by UC Davis Chancellor Linda Katehi and leaders of the campus’ Robert Mondavi Institute for Wine and Food Science, Yudof chose from five blends made with olives grown in California. His favorite? A blend 25 percent Frantoio (Italian) olives and the rest Arbequina (Spanish) olives, the most commonly planted olive in California. Nutty? Yes. Pungent? Check. Bitter? No. Yudof also chose a label design with an image of olives, the UC seal in the middle and the words “President’s Blend.”

“I’m really humbled,” said Yudof, who plans to buy bottles of his blend to send to relatives.

The President’s Blend is expected to be available by the winter holidays. The plan is to sell it at all UC campus bookstores in quarter-liter bottles for $12 apiece.

“We’re hoping we can get out to the other campuses and expose them to really good olive oil,” said Dan Flynn, executive director of the UC Davis Olive Center.

In July, the Olive Center garnered international attention with its study that found many imported olive oils sold in California are not “extra virgin” as their premium labels claim they are. The center is doing a second study to confirm the results, UC Davis professor and sensory scientist Jean-Xavier Guinard said.

The center, part of the Robert Mondavi Institute, collaborates across campus and among producers and the community to promote olive and olive oil research and education. Before testing the olive oil blends, Yudof visited a mobile olive mill, enclosed in a custom-built 38-foot trailer. Olive to Bottle owner Thom Curry brought it for the center’s sold-out course for olive oil producers. “It’s basically like making fruit juice,” Curry said. “The fresher, the better with olive oil.”

Yudof, who also toured the Robert Mondavi Institute’s newly completed, environmentally cutting-edge winery, brewery and food-processing complex, noted the economic promise of California’s growing olive oil industry. California produces almost all olive oil made in the United States, although that amounts to just 1 percent of total domestic consumption in the import-dominated market.

“The olives have the potential to be one of the leading crops in the state, with UC Davis being a leader in the industry, just like with wine and almonds,” Yudof said.

Read more and view a slideshow at Dateline UC Davis.

Posted on Friday, October 8, 2010 at 1:07 PM

Healthful macadamias can enhance a California landscape

In many of California's coastal areas, the climate is ideal for growing crisp but buttery, high calorie yet healthful macadamia nuts.

Macadamia nuts, native of Australia, have the highest amount of beneficial monounsaturated fats of any known nut. They also contain protein, potassium and minerals. A quarter cup serving is about 240 calories; for comparison, a quarter cup of almonds is about 100 calories less. Macadamia's unique texture and delicate flavor complement salads, baked goods and main dishes. The nut's oil has a long shelf life and may be used in salad dressing, for frying and as an ingredient in cosmetics.

UC Cooperative Extension horticulture advisor Gary Bender said macadamias make beautiful backyard trees, planted in the landscape or in large pots or tubs. They prefer fertile, well-drained soils and temperatures that range year-round from the 50s to the mid 70s, although established trees can withstand light frosts.

In their natural rain forest habitat, macadamia trees can grow to 60 feet in height. In California backyards, they will rarely exceed 20 to 30 feet, he said.

Gardeners who plant macadamia trees will have to be patient. Seed to tree takes 5 to 7 years; full production may take as long as 10 years. Once established, however, macadamia trees may continue bearing for over 100 years.

Although commercial macadamia production levels in California pale compared to Hawaii, where farmers harvest 54 million pounds of the nuts a year, macadamias have been grown in the Golden State continuously since 1879. The largest mainland industry is in San Diego County, where the ag commissioner reported growers harvested 192 tons of macadamia nuts from 128 acres of macadamia plantations in 2006, a crop worth $342,336.

UC Cooperative Extension in San Diego County and the California Macadamia Society will sponsor a field day for current and aspiring macadamia growers from 8:45 a.m. to 1:30 p.m. Nov. 6 at the farm of Garry and Patricia Prather, 6686 Via de la Reina, Bonsall, Calif. Registration is $20. At the field day, Bender will explain irrigation scheduling for macadamias. UC Integrated Pest Management advisor Cheryl Wilen will discuss chemical and organic weed control in macadamia production.

More information about the field day is on the San Diego County UCCE calendar. A registration form is on the Gold Crown Macadamia Association website.

Posted on Friday, October 8, 2010 at 6:17 AM

Growing support for local foods

A recent Economic Research Service report from the USDA called Local Food Systems: Concepts, Impacts and Issues provides an overview of the country's local food systems. Some of the findings include:

  • Direct-to-consumer marketing sales of agricultural products more than doubled from 1997 to 2007.
  • The number of farmers markets nationwide tripled from 1994 to 2009.
  • In 1986, there were two community supported agriculture organizations (CSAs). In 2001, there were 400. Early 2010 estimates exceed 1,400.
  • The number of farm-to-school programs (schools feeding students local produce) rose from two in 1997 to 2,095 in 2009.
  • Most farms that sell directly to consumers are small farms with less than $50,000 in total farm sales.
  • Expanding local food systems can increase employment and income in those communities.

To read the report summary click here; to read the whole report click here.

Eating local foods is a great way for consumers to get good nutrition, help the planet and support the local economy. To find a nearby farmers market use USDA’s Farmers Market Locator.

Producers looking to begin direct marketing or wanting to increase sales, have a variety of resources available to them including: UC Agritourism Center, UC Farm and Business Marketplace, and your local UC Cooperative Extension office.

Posted on Wednesday, October 6, 2010 at 7:43 AM
  • Author: Chris M. Webb

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