Division of Agriculture and Natural Resources
Division of Agriculture and Natural Resources
Division of Agriculture and Natural Resources
University of California
Division of Agriculture and Natural Resources

UC blogs

The science of sensory evaluation

Mouth-watering anticipation of holiday food is part of the science of sensory evaluation. (Photo: Pixabay.com)
Holidays fan the flames of our love affair with food. As soon as summer melts into fall, our thoughts leap ahead with mouth-watering anticipation to family gatherings around a Thanksgiving or Christmas feast with all the trimmings. Months before the turkey is carved, you can almost smell it roasting in the oven. You can almost taste the salty goodness of stuffing and gravy. You can almost see colorful visions of home-baked treats dancing in your head.

Your sense of taste, smell, sight, hearing and touch sends signals to your brain that the holiday feasting season has arrived. These basic senses are the tools that influence how much you like – or dislike – the foods you eat.

Sensory evaluation also has practical applications in agriculture. UC Agriculture and Natural Resources researchers and their colleagues often conduct sensory panels for specific food crop studies. Recently volunteer evaluators filed into the sensory evaluation lab at the UC Kearney Agricultural Research and Extension Center to participate in a grape sensory panel. UC researcher Mary Lu Arpaia and USDA researcher David Obenland collected data for a study on the impacts of various storage conditions on grape varieties.

David Obenland of the USDA prepares citrus samples for evaluation.
Evaluators tasted grape samples and recorded their responses to appearance, taste and texture. Samples given to each evaluator were randomly ordered to eliminate bias in the test results. Evaluators were instructed to sip water between tastings to cleanse the palate. Evaluation procedures can vary slightly from product to product. When sensory panels are conducted for avocados, evaluators are instructed to munch on raw carrots before sipping water due to the oil in avocados. The coarse texture of carrots more fully cleanses the palate between avocado tastings. Other sensory panels have been conducted on citrus.

“There's a bit of psychology involved as well. How the product looks can influence your perception of how it tastes. To further eliminate bias, evaluators are intentionally isolated in individual stations so as not to be influenced by their neighbors' reactions,” explained David Obenland.

Grapes are displayed for evaluators to rate fruit appearance.
Sensory evaluation is used by commodity groups like the Table Grape Commission too. Data collected from a grape sensory panel provides important feedback to growers to identify factors that will inform marketing strategies and produce a quality product that consumers are more likely to buy. Evaluators can be recruited from industry groups, in which case they are considered to be “semi-experts,” or from the general public which are classified as “true consumers.”

The sensory evaluation lab at the Kearney Agricultural REC reflects the current philosophy of fruit commodity research that the industry's focus should be on sensory evaluation, from new pest management to horticultural practices to varietal improvements. The lab was completed and dedicated in April 2008 with support from the California Avocado Inspection Committee, Citrus Research Board, Food Machinery Corporation, Peach, Plum and Nectarine Growers of California, Sunkist and Table Grape Commission.

Author: Roberta Barton

Posted on Wednesday, November 25, 2015 at 8:37 AM

Living with wildlife while managing working landscapes

Good fencing is one tool that allows coyotes and sheep to share the open range.
The UC Hopland Research and Extension Center (UC HREC) will host workshops on Dec. 1 and 2 to foster understanding and encourage community dialog about ranching on a landscape with populations of coyote, black bear, mountain lions and other wildlife.

“Mendocino County supports many ranchers and our communities enjoy locally produced lamb, beef, milk, cheese and other agricultural products,” said Kimberley Rodrigues, director of UC HREC. “Along with these opportunities come challenges associated with living alongside some of our resident wildlife. The workshops will help local residents deal with these challenges.”

Rodrigues – who has a doctorate degree in environmental science and has been a leader in outreach, strategic facilitation and partnership development for 25 years – has been actively involved in wildlife management at the 5,300-acre HREC since she arrived in mid-2014.

“I quickly realized the biggest challenge to maintaining a sustainable flock of sheep here in our location is addressing predation issues, primarily by coyotes,” Rodrigues said. “With some improvements to our fences, changes in pasture rotations and increased use of guard dogs, losses of sheep to coyotes are now at an acceptable level. We hope to share our own experience, hear from diverse perspectives and experiences at these events and would like HREC to become a hub for future learning on this topic.”

Recent discussion and decisions made by the Mendocino County Board of Supervisors regarding their contract with USDA Wildlife Services (WS) and their use of an integrated wildlife damage management program prompted UC HREC to provide a space for two workshops to allow learning on wildlife management and community conversation.

The Dec. 1 workshop will focus on scientific design and is implemented by USDA WS. It provides an opportunity to hear experts from USDA, the Californi Department of Fish and Wildlife, UC Cooperative Extension and Defenders of Wildlife to discuss the most up-to-date research in wildlife behavior and non-lethal control methods.

The Dec. 2 community conversation workshop is hosted by UC HREC and includes current research from UC Agriculture and Natural Resources, wildlife biologists and discussion of the challenges associated with ranching in Mendocino County from the Magruder family and other local ranchers. The day will culminate in discussion groups on topics ranging from integrated wildlife management tools to understanding local, state and federal connections.

The public may attend either day or both days. Registration for the two workshops is separate.

“Topography, surrounding environments, community viewpoints, available funds and the kind of animals being farmed are all part of the picture – there is no easy solution,” said Hannah Bird, UC HREC community educator. “Ranchers and land managers need to know what tools are available to them and the implications and benefits of each of these tools. Attending both workshops will provide a deeper understanding of the issues.”

Community members, ranchers, land managers and members of non-profit organizations are invited to attend. The workshops will be at the Rod Shippey Hall, Hopland Research and Extension Center, 4070 University Road, Hopland, CA 95449. Registration is $30 for each day (including lunch) and must be made in advance. The registration deadline is Nov. 23. Space is limited.

Sign up for the Dec. 1 USDA WS workshop at http://ow.ly/TYhBd and the Dec. 2 community conversation workshop at http://ow.ly/TYhos.

More on the University of California Hopland Research and Extension Center:

The Hopland Research and Extension Center is a multi-disciplinary research and education facility run by the University of California, Agriculture and Natural Resources Division. As stewards of more than 5,300 acres of oak woodland, grassland, chaparral, and riparian environments their mission is to find better ways to manage our natural resources and conduct sustainable agricultural practices, through science, for the benefit of California's citizens.

Author: Hannah Bird

Posted on Monday, November 23, 2015 at 10:38 AM

El Niño expected to drench California

Shasta Lake in 2009. El Niño precipitation may help refill the lake after four years of drought. (Photo: CC BY 3.0 by Apaliwal via Commons)
Brace yourself for El Niño. All major climate models indicate that the current El Niño will be the strongest on record in terms of sea surface temperature departures from normal.

Climate scientists refer to the anomaly as ENSO, for El Niño Southern Oscillation. The term describes the fluctuations in temperature between the ocean and atmosphere in the east-central Equatorial Pacific, just west of the Peruvian coast. The area is roughly between the International Date Line and 120 degrees west.

The ENSO cycle has three distinct phases: El Niño, La Niña and neutral. El Niño is defined when sea surface temperature is unusually warm for an extended period of time. La Niña is declared when equatorial Pacific is unusually cool for an extended period of time. Neutral phase is defined when the sea surface temperature is considered normal.

These large-scale changes in the surface water temperatures are linked to changes in the strength of the trade winds blowing from east to west across the region, which impacts weather patterns across the globe.

According to the NOAA Climate Prediction Center and International Research Institute for Climate and Society, a strong El Niño will continue through the Northern Hemisphere during the winter of 2015-16, followed by weakening and a transition to ENSO-neutral during the late spring or early summer.

Source: http://www.ncdc.noaa.gov/monitoring-references/dyk/elnino-2015-2016
What does that mean for California? In general, during a strong El Niño, California experiences a wetter than normal winter. During six strong El Niño events (1957-58, 1965-66, 1972-73, 1982-83, 1991-93 and 1997-98), California received 120 to 160 percent of normal precipitation from October through March. In addition to the wetter than average conditions forecast for the 2015-16 rainy season, the winter is also has a warmer than normal temperature outlook.

Some of the expected outcomes are:

  • Increased risk of flooding for California, since most of the precipitation is expected in the form of rainfall, rather than snow. Increasing streamflow in undammed rivers and quick filling of reservoirs that come with the potential for reservoir releases for flood control.

  • Early bud breaking in many agricultural crops due to warmer than usual conditions. This can have significant yield impact on crops that rely on sufficient chill for proper development, such as citrus, apples, tree nuts and grapes.

  • Increased aquifer recharge through so-called groundwater banking.

UC Agriculture and Natural Resources researchers will continue to monitor the El Niño Southern Oscillation and how it influences weather patterns in California. Future articles will provide detailed discussions on El Niño, with a focus on water resources impacts, effects on crops and potential for groundwater recharge.

An initiative to improve California water quality, quantity and security is part of the UC Division of Agriculture and Natural Resources Strategic Vision 2025.

Authors: Tapan Pathak, UC ANR Cooperative Extension specialist in climate adaptation in agriculture and Samuel Sandoval Solis, UC ANR Cooperative Extension specialist in water resources

Posted on Thursday, November 19, 2015 at 8:34 AM

Have a Happy Thanksgiving without unzipping

A typical Thanksgiving meal has more calories than many people need in a whole day. (Photo: Satya Murthy, Flickr)
For many of us, Thanksgiving is truly a feast, and we are preparing our appetites for large servings of turkey, stuffing, and pumpkin pie. In fact, the majority of people consume more than 2,000 calories in their Thanksgiving meal, including appetizer, turkey and the trimmings and dessert, reports Diabetes.org. That's more than a sedentary man should eat in a whole day to maintain a healthy weight, according to the USDA's ChooseMyPlate.gov. This year, you can enjoy the holiday without overeating by serving a healthy and balanced meal. 

  • Portion control: Thanksgiving is about choices. Think about which dishes you don't mind skipping, and plan to fill your plate only once. It's easy to get carried away going back for second and third helpings.

  • Fruits: Get your serving of fruit with a fruit-based dessert. Baked apples, poached pears and fresh figs are a few festive options.

  • Grains: Use whole grain or 100 percent whole wheat bread for a stuffing rich in fiber. 

  • Protein: Serve yourself 3 ounces of roasted turkey or a portion the size of your palm. Skip the fat by removing the skin on your turkey before eating it. Go easy on the gravy.

  • Vegetables: Choose vegetable side dishes that include roasted or cooked vegetables, and skip the creamy sauces and added fat. Instead, season vegetables with fresh herbs to add flavor.  

  • Dairy: Try non-fat Greek yogurt as a healthier topping for side dishes than sour cream or butter.

  • Don't forget to be active. After the holiday meal, go for a walk, bike ride or play football with the family. 

Not sure what to do with your leftovers? Reinvent your Thanksgiving feast with these quick and easy one-sentence leftover recipes. 

  • Cranberry smoothies
    Whirl cranberries with frozen low-fat yogurt and orange juice.

  • Crunchy turkey salad
    Toss cubed turkey with celery, apples, and light mayo with shredded spinach.

  • Stuffing frittata
    Mix stuffing with egg and cook thoroughly, pancake-style.

  • Turkey berry wrap
    Wrap sliced turkey, spread with cranberry sauce and shredded greens in a whole wheat tortilla. 


 Recipe source: www.eatright.org

 Author: Melissa Tamargo

Posted on Thursday, November 12, 2015 at 11:17 AM

Counties can offset greenhouse gas emissions with stream restoration

Elise Gornish, UC ANR Cooperative Extension specialist in restoration ecology, and John Parodi, restoration program manager for Students and Teachers Restoring our Watersheds, looking at a 10-year-old stream restoration project.
The revegetation of streams and creeks that crisscross California rangeland can play a significant role in helping counties meet carbon emission standards.

“We have long known that stream revegetation improves wildlife habitat and enhances water quality, but that fact that the vegetation and trapped sediment capture carbon underscores the importance of this conservation practice,” said David Lewis, a UC Agriculture and Natural Resources (UC ANR) watershed management advisor for Marin, Sonoma and Napa counties.

Going back to the time when Gen. Mariano Guadalupe Vallejo was running long-horn cattle on a vast tract of land in Alta California, ranchers didn't always understand the value of the trees, shrubs and grasses that grew around rangeland waterways.

Vallejo removed vegetation because it provided a hideout for grizzly bears that attacked his cattle and pilfered hides being tanned. In later years, authorities coached landowners to alter streams and remove plants to increase stream flow and improve flood control.

Beginning in the 1960s, the environmental impacts of removing trees and plants became apparent and public funds were made available to share in the cost of restoring streamside vegetation on private land, said Lewis, who is also director of UC ANR Cooperative Extension in Marin and Napa counties. Over a period of three years, he and a team of UC and local scientists studied the stream revegetation projects that took place from about 1970 to just recently. They documented the carbon sequestration benefits of stream revegetation and calculated the value based on the current market for carbon credits. The results were shared in a report released this month, Mitigating Greenhouse Gas Emissions through Riparian Revegetation.

“In Marin County, for example, the cost per metric ton for carbon dioxide equivalence sequestered with revegetation was $19.75. The carbon market is currently paying about $12.50,” Lewis said. “There is about $7 that we haven't made up. But when you think about the other benefits of riparian restoration – reduced sediment, restored habitat for migratory songbirds and other wildlife – I would bet that value to be much greater than $7.”

Lewis' research will be of interest to county governments as they strive to reduce total greenhouse gas emissions to comply with the requirements of the 2006 California Global Warming Solutions Act (AB 32). The legislation requires California to reduce its greenhouse emissions to 1990 levels by 2020. As part of the law, local governments must write a “Climate Action Plan” to report how they will monitor and track progress in reducing and offsetting greenhouse gas emissions.

“It may make sense for governments and project proponents to invest in creek restoration and other farm conservation practices to reach and surpass their carbon emission reduction goals,” Lewis said.

Through 1990, Marin ranchers restored more than 25 miles of stream with willows, oaks and other trees and shrubs. Those plants trapped sediment contain an estimated 80,265 metric tons of sequestered carbon – an amount equal to emissions from 61,959 passenger cars in one year.

Lewis estimates there are several hundred miles of unrestored streams in Northern California coastal counties. And the implications of this study have application for rangeland streams throughout California.

“This represents tremendous potential for carbon sequestration,” Lewis said. “And rancher interest in stream restoration has never been higher. Working with the ranchers to plant trees and shrubs along our waterways presents a significant opportunity to offset carbon emissions.”

An initiative to maintain and enhance sustainable natural ecosystems is part of UC Agriculture and Natural Resources Strategic Vision 2025.

Posted on Monday, November 9, 2015 at 9:06 AM

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