Direct spectrophotometric determination of quercetin content in onions (Allium cepa L.) was investigated as a possible alternative to high-performance liquid chromatography (HPLC) analysis. Quercetin content in five onion varieties was monitored at 362 nm and quantified using simple spectrophotometric and HPLC methods. HPLC revealed that 3,4'-Qdg and 4'-Qmg comprised up to 93% of total flavonol content detected in the studied varieties. These major quercetin conjugates combined (3,4'-Qdg + 4'-Qmg) and total flavonol conjugates quantified by HPLC correlated closely with spectrophotometer values. Correlation coefficients were 0.96 (P < 0.0001) for 3,4'-Qdg + 4'-Qmg and 0.97 (P < 0.0001) for total flavonol conjugates in onion. Simple spectrophotometric procedure proved to be a valid, efficient, and cost-effective method for the quantification of total quercetin in onion. Chemical names used: quercetin-3,4'-O-diglucoside (3,4'-Qdg); quercetin-4'-O-glucoside (4'-Qmg).
Kevin A. Lombard, Emmanuel Geoffriau and Ellen Peffley
Stefan Sutherin, Kevin Lombard and Rolston St. Hilaire
To fill a critical need for more information on desert-adapted low water-use landscape plants, we created Southwest Plant Selector, a mobile plant selector application (app) of landscape plants from the New Mexico Office of the State Engineer (NMOSE) online database of New Mexico landscape plants. The app, which is available for Apple® iPhone® and iPad®, was designed for homeowners and lists plant descriptive items, pest and disease information, and a photograph of the plant. The app also displays a graphic of the three regions of New Mexico and El Paso County, TX, overlaid with text that provides plant water requirements for each of those regions. An associated web page allows users to calculate supplemental plant water requirements for individual plant selections. Homeowners can select landscape plants based on botanical or common name, plant type, and category, region, and sun exposure. Even with the specific user base of New Mexico residents who own Apple® mobile devices, the app has been downloaded nearly 5000 times since its first release on 29 June 2012. New Mexico State University (NMSU) Cooperative Extension Service agents now use the app as a part of their standard toolkit for interactions with homeowners. Mobile technologies such as smartphone and tablet apps are gaining prominence as outreach tools. Land-grant institutions can be more involved in leveraging mobile application technologies for education and outreach. This article describes a process that land-grant institutions can use to produce apps for horticulture outreach.
Kevin A. Lombard, Emmanuel Geoffriau and Ellen B. Peffley
Because of potential benefits on human health, the content of quercetin, the major flavonol found in onion (Allium cepa), could become a selection trait in breeding programs. Total flavonol concentration in onion was examined by spectrophotometric analysis at 374 nm in three long-day hybrid cultivars grown at three locations (Parma, Idaho; Grand Rapids, Mich; Elba, N.Y.), and in three shortday hybrid cultivars grown at one location in Georgia in three different fields. Mean total flavonol concentrations for long-day hybrids ranged from 176 to 232 mg·kg-1 (ppm) fresh weight and 110 to 173 mg·kg-1 fresh weight among short-day cultivars. No significant effect of location (state or field) was detected (P > 0.05). A significant (P > 0.05) cultivar by field interaction was detected in the short-day experiment, with the hybrid `Sweet Vidalia' showing significant differences among fields. Overall, our results suggest that quercetin content in onion, as expressed by the total flavonol content, does not vary depending on the growing origin, and therefore could be evaluated effectively in breeding or commercial material.
Ellen B. Peffley, Kevin Lombard, Cynthia McKenney and Richard Durham
A plant propagation course was developed for delivery on the World Wide Web. Plant Propagation Methods is one of two foundation courses required of students with either a major or minor in horticulture. The course is accessed via the Texas Tech Univ. Horticulture website, www.pssc.ttu.edu. The delivery software is Web-CT Tutorial and access is password protected. The course has been offered two semesters, Fall 1999 and Spring 2000. Overall, student evaluations have been very favorable. The ratings for the first time offering were a 100% excellent rating was given for stimulating student interest and concepts pointed out; 67% excellent rating for effectiveness of the course, presents challenging ideas, stresses important points, uses visual materials, defines new terms, and provides an overview/objective. Students gave an overall rating of good for the organization of the course. The only negative response by the students was that they said the class was very hard because it was not in a structured classroom setting.
Kevin Lombard, Bernd Maier, Franklin J. Thomas, Mick O’Neill, Samuel Allen and Rob Heyduck
Commercial wine grape (Vitis sp.) production in northwestern New Mexico and the greater Four Corners region is now supported by four wineries. The challenges of growing grape vines in northwestern New Mexico include cold winter temperatures and killing spring frosts exacerbated by a semiarid climate and elevations exceeding 1700 m. Nineteen nongrafted European wine grape (Vitis vinifera) and interspecific hybrid wine grape cultivars were planted in 2007 and evaluated between 2010 and 2012. Among European wine grape cultivars, Agria, Malbec, Sangiovese, Viognier, Müller-Thurgau, and Sauvignon Blanc performed poorly or failed altogether. Interspecific hybrid cultivars Baco Noir, Kozma 55, Leon Millot, Chardonel, Seyval Blanc, Siegfried, Traminette, Valvin Muscat, and Vidal Blanc showed greater adaptability to a high-elevation intermountain western U.S. site, yielding on greater than 71% of their vines in each year (except Kozma 55 which only produced on 38% of its vines in 2012 due to severe spring frost damage). We speculate that fruit-bearing shoots on these vines arose from latent buds that survived when primary buds were killed from spring frost events. Once vines were established, grape berry sugar and pH appeared to be within acceptable ranges (3-year mean above 21% soluble solids and juice pH of 3.2), suggesting regional potential to produce favorable wines within acceptable commercial wine grape production ranges. Selection of sites without considerable frost risk and other mesoclimate variances is critical when considering vineyard establishment at high-elevation locations.
Kevin A. Lombard, Ellen Peffley, Leslie Thompson, Emmanuel Geoffriau and Jay Morris
The flavonol quercetin has been reported as having many health benefits, including a reduction in the risk of developing cardiovascular disease, stroke, and some types of cancer. The overall content of quercetin in onion was examined in four yellow varieties (`Rio Rita', `RNX 10968', `Predator', and `Tamara') and one red variety purchased at a local grocery store. Each bulb was quartered, with one quarter saved as a control and the other three quarters subjected to three cooking treatments that simulated common domestic processing methods of preparing onion. The treatments included sautéing in sunflower oil for 5 minutes at 93 °C, baking for 15 min. at 176 °C, and boiling for 5 minutes in distilled water. Samples were frozen in liquid nitrogen, ground to a fine powder, blended with 80% EtOH, and filtered for quercetin extraction. The filtrate was then analyzed with a spectrophotometer (uv 374 nm). Quercetin concentrations were obtained in mg quercetin/kg fresh weight of tissue by regressing spectrophotometer readings onto a standard curve. Significant differences between varieties were found when examining fresh samples alone with the red variety containing the highest content of quercetin. Results of cooking showed that sautéing produced an overall 27% gain in quercetin concentration (significantly higher than the fresh control), baking produced an overall 4% gain in concentration (insignificant from the fresh control), while boiling produced an overall 18% loss in quercetin concentration (significantly lower than the fresh control).