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

UC Food Blog

Avocado production in the San Joaquin Valley gets closer

Planting avocados in research plots at the UC Lindcove Research and Extension Center.
The San Joaquin Valley is the heart of California agriculture, but hasn't been a hospitable home for commercial avocado production. UC Cooperative Extension specialist Mary Lu Arpaia is conducting research to change that.

Avocados are native of semi subtropical high elevation rainforests in Mexico and Central America. A delicious and highly nutritious fruit, the cultivation of avocado has spread around the world. In California, growers are having commercial success in areas with year-round mild climates, such as San Diego and Ventura counties.

Though avocados are frost sensitive to be sure, it is not the cold winter climate that is the greatest impediment to avocado production in the state's inland valleys. It's the heat.

“Plant leaves have stomata, small openings that allow water vapor to move out of the plant to cool the leaf surface,” Arpaia said. “It works something like perspiration on people. Moisture exits the pores and cools the skin.”

The stomata on the leaves of Hass avocados – the variety most favored by California consumers – close when the temperature rises above 90 degrees. No moisture is released from the closed stomata and the plant overheats, causing fruit drop.

“To grow avocados in the valley, we need to have a variety that can tolerate heat better than Hass,” Arpaia said.

An avocado variety currently named 465202-99 was planted in 2013 and already has a substantial crop for 2015. It looks nice and has performed well in taste panels.
Over the past four years, Arpaia has planted avocado varieties selected by UC Riverside at the UC Lindcove Research and Extension Center near Exeter. Twelve different varieties are now growing in the plot. The UC Riverside selections have undergone rigorous testing for yield, the length of time ripe fruit can remain on the tree, and eating quality.

“The ones that we're testing in the field have eating quality comparable to Hass,” Arpaia said.

Lindcove is situated where the valley floor is gently rising toward the Sierra Nevada. The slope allows cold air to slip down to lower elevations, giving farmers in the area an advantage of a few degrees in the winter. The geography has made the area an important location for citrus production. But heat-tolerant avocados could be an alternative.

East-side citrus farmers may be looking for other options if Huanglongbing (HLB) disease makes its way to the area. Already, the pest that spreads HLB, Asian citrus psyllid, is established in some parts of the valley and spreading. Once a tree is infected with HLB, it cannot be cured.

“Growers have made good money on avocados,” Arpaia said. “In the San Joaquin Valley, water is relatively cheap and we have better water quality than San Diego County. There are good, well-drained soils. Avocados' frost sensitivity is similar to lemons. If farmers have property where they can grow lemons, they could try avocados.”

An initiative to enhance competitive and sustainable food systems is part of the UC Division of Agriculture and Natural Resources Strategic Vision 2025.

Posted on Tuesday, January 13, 2015 at 8:18 AM

Scientists ask USDA to add water to MyPlate

The UC Nutrition Policy Institute would like MyPlate to include an icon for water, such as the one shown above.
The brightly colored divided plate that lays out the USDA's model for healthy eating needs one little tweak, says the director of the UC Nutrition Policy Institute Lorrene Ritchie. Don't take anything away, but add H20.

Ritchie has joined with dozens of nutrition and health professionals around the country to ask that the USDA put water onto MyPlate.

“We don't have all the answers to overcoming obesity, but the research on sugar-sweetened beverages is very clear,” Ritchie said. “When you drink beverages like soda, sports drinks or punch, the sugar gets absorbed very rapidly and the body doesn't recognize the calories. The result is excess calories and weight gain.”

The USDA introduced MyPlate in 2011 to reflect the message of its Dietary Guidelines for Americans, 2010. Federal law requires that the guidelines be reviewed, updated and published every five years.

“USDA officials say that, in order to change MyPlate, there must be more information in the dietary guidelines about water,” Ritchie said. “We are working through the public comment process to ask the advisory board to promote water as the beverage of choice.”

The ultimate goal – a new water icon on MyPlate – is important because of its high visibility. MyPlate is found on elementary school classroom walls and cereal boxes; at community gardens and the grocery store produce aisle.

Drinking plain water is important for child nutrition and obesity prevention.
In preparing for a visit with USDA officials at their Washington, D.C., headquarters, Christina Hecht, UC Nutrition Policy Institute coordinator, asked UC Cooperative Extension specialists in California for input on MyPlate. Their enthusiasm was unanimous.

“They see MyPlate as the face of the dietary guidelines and are very supportive of using the image as a teaching tool,” Hecht said. “They also supported the idea of adding a symbol for water.”

She shared the California educators' thoughts on MyPlate with her USDA contacts. “When they get a story from the field, it really matters to them,” Hecht said.

Ritchie and her colleagues around the country submitted a “Best of Science” letter to the Dietary Guidelines Advisory Committee imploring them to strengthen the language for drinking water.

“Current research indicates that children, in particular, are subject to ‘voluntary dehydration' from low intake of plain water,” the letter says. “Between 2005 and 2010, more than a quarter of children aged 4 to 13 years old in the U.S. did not have a drink of plain water on two consecutive days.”

Instead, they are drinking sugary beverages. National surveys in the early 2000s found that, on any given day, 84 percent of 2- to 5-year-old children drank sugar-sweetened beverages like sodas, sports drinks and fruit punch. The calories amounted to 11 percent of the children's total energy intake.

Lorrene Ritchie, director of the UC Nutrition Policy Insitute, testifies at a congressional hearing about strategies to reduce childhood obesity in the U.S.
Since the 2010 Dietary Guidelines were issued, knowledge about the magnitude of risk and extent of adverse effects from sugar-sweetened beverages has increased. The Best of Science letter outlines for the advisory board many of the proven consequences of sugar-sweetened beverage consumption in America:

  • Sugar-sweetened beverages – including sodas, juice drinks, pre-sweetened tea and coffee drinks, and fortified or energy drinks – are among the top sources of calories for children and adolescents.
  • Between the late 1960s and early 2000s the consumption of sugar-sweetened beverages doubled.
  • While the American Heart Association recommends no more than 6 teaspoons of added sugars per day for women and 9 teaspoons per day for men, the average U.S. consumption is 17 teaspoons per day.
  • Low-income populations have higher intakes of sugar-sweetened beveragesand Latino children drink more of them than white children.
  • Cardiovascular disease, present in more than one-third of American adults, is now understood to be exacerbated by the inflammatory effects of excess sugar consumption.
  • Excess sugar consumption is a risk factor for non-alcoholic fatty liver disease, a precursor to diabetes.
To learn more, read the Best of Science Letter signed by 14 prominent nutrition educators from around the nation by clicking the link below.
 
Posted on Wednesday, January 7, 2015 at 7:15 AM

Protecting California’s parsley crop

Parsley with disease symptoms.
When most people think about parsley, they likely think of it as an inedible garnish a chef places on their plate. But parsley is widely used in dried spice mixes, soups and other prepared foods as well as in salads and other recipes. Currently, California produces almost 2,600 acres of parsley at a value of $18 million a year, with Monterey and Ventura counties accounting for 49 percent of the state's parsley production.

California parsley is produced typically in high volumes and with high quality. However in the past few years, growers began to observe unfamiliar disease issues in their parsley fields. Leaf spots, blighted foliage and yellowed plants contributed to loss of quality and reduced yields. Steven Koike and Oleg Daugovish, UC Cooperative Extension advisors in Monterey and Ventura counties respectively, stepped in to investigate the new parsley problems. They collaborated with farmers and pest control advisers to understand the extent of the problems and to obtain samples of the diseased crops. 

The UC Cooperative Extension plant pathology diagnostic lab in Salinas was successful in isolating and identifying several pathogens that were responsible for causing the disease symptoms. Working with USDA, they found that three new diseases were present in California parsley crops: bacterial leaf spot, Stemphylium leaf spot, and Apium virus Y disease.

Two of these problems are seedborne, so future management will include the use of pathogen-free seeds. The Apium virus Y pathogen is found in weeds, so growers will need to remove poison hemlock, among others.

Previous to this research, some growers were spraying symptomatic fields because they believed that a disease called late blight was responsible for the disease symptoms. Growers have now ceased making these sprays, eliminating the use of unnecessary chemicals and saving costs.

Click here for more on this research.

California produces almost 2,600 acres of parsley at a value of $18 million a year.
Posted on Tuesday, January 6, 2015 at 11:03 AM
  • Author: Jennifer Rindahl

A New Year and a 'new'tritious new you!

It's that time of year when many people choose a resolution that helps them kick a bad habit, but sometimes making a sudden change is hard to stick to. This year, make a resolution you can actually keep by filling half your plate with fruits and vegetables. Need some ideas to get started?

Breakfast: Drink 4 oz. of 100 percent fruit or vegetable juice. Top cereal or yogurt with 1/2 cup of berries or sliced banana.

Lunch: Try a salad as your main dish with the dressing on the side.

Snacks: Trail mix with dried fruit or a piece of fruit such as an apple or an orange is an energizing snack that can also be satisfying if you have a sweet tooth.

Dinner: Enjoy a side of mixed vegetables or have fruit for dessert. All forms of produce count: dried, fresh, 100% juice, canned, and frozen. Try a variety of fruits and vegetables so you don't get bored!

Here are some tips for you and your family to try new foods:

New foods take time. Offer new foods many times. Children don't always take to new foods right away.

Keep portions small. Let your kids try small portions of new foods that you enjoy. When they develop a taste for many types of foods, it's easier to plan family meals. 

Be a good role model. Try new foods yourself and describe its taste, texture, and smell to your family.

Offer only one new food at a time. Serve something that is familiar to your child along with the new food. Offering too many new foods all at once could be overwhelming. 

Tex Mex Skillet

  Ingredients

  • 1/2 medium head lettuce
  • 1 medium green bell pepper
  • 1 large tomato
  • 1 small jalapeño pepper
  • 1/2 medium red onion
  • 2 cloves garlic or 1/4 tsp garlic   powder
  • 2 oz low-fat cheddar cheese
  • 1 (15 1/2 oz) can of black beans
  • 1 pound ground beef, chicken, or turkey
  • 1 (12 oz) bag of frozen corn
  • 1/2 cup water
  • 3/4 teaspoon chili powder
  • 1/4 teaspoon salt and cumin
  • Ground black pepper
  • 8 whole wheat flour tortillas

Directions

  1. Rinse and peel vegetables.
  2. Chop lettuce, mince garlic, halve jalapeños, and dice peppers.
  3. Grate tomato, onion, and cheese.
  4. Drain and rinse beans.
  5. In a large skillet over medium heat, cook meat, bell pepper, and garlic until meat is lightly browned.
  6. Stir in corn, beans, water, and     spices. Simmer for 10 minutes.
  7. Make a salsa using jalapeño, tomato, and onion. Stir and set aside.
  8. Divide meat mixture among       tortillas. Top with cheese, salsa, and lettuce. Roll up and enjoy!

Melissa Tamargo is a program representative with the UC Cooperative Extension Expanded Food and Nutrition Education Program state office.

Sources: http://www.fruitsandveggiesmorematters.org/a-new-years-resolution-you-can-easily-keephttp://www.choosemyplate.gov/preschoolers/picky-eaters/new-foods.html

Recipe: www.choosemyplate.gov 

 

 

Posted on Monday, December 22, 2014 at 8:58 AM

Five ways NOT to poison friends and family during the holidays

The food-safety danger zone is between 40 degrees F and 140 degrees F.
‘Tis the season for gathering with friends and family and eating. Whether you celebrate Christmas, Hanukkah, Kwanzaa or Festivus for the rest of us, many of us invite people to our homes during the holidays and leave food out to graze. Leaving food out for more than two hours can be hazardous to your health and that of your guests, caution UC Cooperative Extension nutrition experts.

You may be thinking, “My family has eaten food that has been sitting on the table longer than two hours and survived.” Consider yourself lucky.

“We keep learning more about foodborne illness,” says Patti Wooten Swanson, UC Cooperative Extension nutrition advisor in San Diego County. “We probably did get sick, but we thought it was something else, like the 24-hour flu.”

She added that kids, diabetics, pregnant women, older adults and people with weakened immune systems are more susceptible to foodborne illnesses.

For the holidays and all year long, Wooten Swanson offers these food safety tips:

  • Thaw turkey or meat in the refrigerator.
  • Don't wash raw meat or poultry in the sink before cooking.
  • Use a meat thermometer to determine when meat or poultry is done.
  • Put leftovers in the refrigerator within two hours.
  • On the fourth day, throw leftovers away.

Guacamole and salsa shouldn't be left out for longer than 2 hours.
Thawing foods correctly and storing them at the right temperatures is important, said Wooten Swanson.

“Bacteria grow very rapidly,” she said. “From 40 degrees to 140 degrees is what we call the danger zone. We encourage you to get food out of that temperature range as soon as possible. Don't let food sit on the table after you finish eating and go to watch TV.”

While you're watching football, she also recommends not leaving food out the length of a game.

“Chips are fine to leave out,” Wooten Swanson said, “But put the salsa and guacamole in small containers, then put out new bowls at halftime. Take away the original containers to wash or discard.You don't want to refill a bowl that has been out for 2 hours.”

Washing your hands can prevent bacteria from spreading to food.
Food safety begins with clean hands.

“We put an emphasis on hand washing because it can prevent cross-contamination, which helps prevent foodborne illness and can keep us healthy during the flu season,” said Connie Schneider, director of the UC Youth, Families and Communities Statewide Program.

She recommends rubbing your hands together with soap and water for 20 seconds to thoroughly clean them.

The UC Expanded Food and Nutrition Education Program (EFNEP) teaches hand washing as a food safety practice in its nutrition classes for adults and children. After taking the class in San Diego County, 72 percent of the 340 participating adults improved their safe food-handling practices and 55 percent of 1,231 children improved, said Wooten Swanson, who oversees the nutrition and food safety education program.

For more food safety resources, visit UC Cooperative Extension's  "Food Safety for the Holidays" website http://ucanr.edu/HolidayFoodSafety and Nebraska and Iowa State Cooperative Extension's food safety website at http://www.4daythrowaway.org.  For USDA recommended temperatures for cooking meat, visit http://blogs.usda.gov/2011/05/25/cooking-meat-check-the-new-recommended-temperatures.

Posted on Wednesday, December 17, 2014 at 8:30 AM

First storyPrevious 5 stories  |  Next 5 stories | Last story

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

Webmaster Email: zgates@ucdavis.edu