1.  Barkworth, and D.R. Dewey. "INTERMEDIATE WHEATGRASS Thinopyrum Intermedium."United States Department of Agriculture (Contributor: USDA, NRCS, Idaho State Office). Web. 3 Apr. 2015.

2.  "Soil Erosion and Degradation." World Wild Life. Web. 3 Apr. 2015. https://www.worldwildlife.org/threats/soil-erosion-and-degradation.

3.  "Sustainable Water Management – Local to Global." Pacific Institute. Web. 3 Apr. 2015. <http://pacinst.org/issues/sustainable-water-management-local-to-global/>.

4.  Nyren, Paul E., Goujie Wang, Bob Patton, Quingwe Xue, Gordon Bradbury, Mark Halvorson, and Ezra Aberle. "Evaluation of Perennial Forages for Use as Biofuel Crops in Central and Western North Dakota." North Dakota Natural Resources Trust and Industrial Commission of North Dakota, 7 Dec. 2009. Web. 3 Apr. 2015. <http://www.ag.ndsu.edu/centralgrasslandsrec/biofuels-research-1/2011-report/Biomass_for_ethanol.pdf>.

5.  "Gliadin, Alpha/beta (IPR001376)." InterPro Protein Sequence Analysis & Classification. Web. 3 Apr. 2015. <http://www.ebi.ac.uk/interpro/entry/IPR001376>.

Intermediate Wheatgrass (IWG) or Thinopyrum intermedium, is a perennial crop of interest to agronomists due to its extensive root system that result in reduced soil and water erosion, and increased nitrogen fixation. However, farmers will be reluctant to plant this crop without an established market, which relies on the characterization of IWG grains for parameters relevant to food use. Therefore, the objective of this study was to analyze lines of IWG for the grains’ chemical composition, functionality, and baking properties. Sixteen IWG lines along with one bulk IWG sample and wheat controls were analyzed for proximate composition, dietary fiber, starch composition, and gluten forming proteins, following standard analytical procedures. Starch pasting properties were monitored using a rapid visco analyzer. Dough rheology was assessed using farinograph and Kieffer. Bread baking tests were also performed following AACCI method. Compared to wheat controls, IWG samples had higher protein and dietary fiber contents, yet were deficient in high molecular weight glutenins (HMWG), an important protein component responsible for dough strength and elasticity. Slight variation in protein profile was observed among the different lines. The fat and ash content of IWG samples were similar to those of the wheat controls. Both farinograph and Kieffer showed weaker IWG dough strength compared to that of controls. These findings suggest that IWG has a superior nutritional profile, but poses challenges for baked products that require dough rising properties. These results can be explained by the lack of gluten network formation, and the higher fiber content that competes with protein and starch for water. This data will assist breeders in their screening and future breeding efforts for the development of IWG lines suitable for food applications. Enhancement of IWG’s protein functionality, determining the effect of fiber on dough development, and the impact of dough conditioners need to be studied.

Chemical Characterization, Functionality, and Baking Quality of Intermediate Wheatgrass (Thinopyrum intermedium), a Novel Perennial Crop

Citra Rahardjo, Kristin Whitney, Senay Simsek, Tonya Schoenfuss, and Baraem Ismail

Department of Food Science and Nutrition, University of Minnesota, Twin Cities, 1334 Eckles Avenue, St. Paul, MN 55108

•  All IWG samples had higher protein and total dietary fiber content when compared to wheat controls (Figures 1 and 2).

•  % Ash was higher in IWG samples (due to higher bran to endosperm ratio), but % fat was similar to that of wheat controls.

•  Total starch content among IWG were slightly lower than that of controls, but amylose to amylopectin ratio was similar (Figure 3).

•  Despite the high protein content, IWG samples were deficient in HMWG (Figure 4). Since HMWG is important for dough functionality especially for dough strength and elasticity, this may affect its properties and limit its applications in bread making.

•  According to the farinograph data (Figures 5 and 6), the functionality of HRW dough sample was superior when compared to IWG samples. HRW sample had higher stability time compared to IWG samples.

•  Kieffer analyses were also conducted to compare the resistance to extension and extensibility of the dough samples (Figure 7). The data generated showed that wheat control samples were superior in terms of resistance to extension, followed by bulk IWG sample – Kernza, then the other 16 IWG samples. While for extensibility, one wheat control sample (Arapahoe) is noticeably higher, followed by HRW and bulk IWG (Kernza).

•  Starch pasting temperature (Figure 8) is inversely proportional to the total starch content, which may happen due to higher protein and fiber that compete for water. On the other hand, the final viscosity is directly proportional to the total starch content.

•  Bread volume was generally higher for wheat samples - especially for Arapahoe, when compared to the IWG samples (Figure 9).

•  When comparing bread pictures (Figure 10), wheat controls had bigger air holes and rounded tops; while IWG samples appeared denser and some of them had flat surface.

•  IWG is a novel perennial crop, native to Asia and Europe, and got introduced to the US in 19321.

•  The environmental benefits of perennial crops in comparison to annual crops include reduced soil and water erosion, reduced soil nitrate leaching, increased carbon sequestration, and reduced inputs of energy and pesticide1.

•  According to World Wildlife Fund (WWF),“Half of the topsoil on the planet has been lost in the last 150 years,”and not only it does affect the amount of available soil, but also the quality of the current soil.“Compaction, loss of soil structure, nutrient degradation, and soil salinity,”are several of many examples of soil quality degradation that currently is happening2. Pacific Institute also mentions that water supply is continually degrading and that many“major rivers –including the Colorado River in the western United States and the Yellow River in China – no longer reach sea in most years,”which proves the water shortage that the world is currently facing3.

•  IWG traditionally has only been used as animal feed1. However, current research shows promising potential for food use & biofuel4.

•  From a consumer perspective, the engagement in purchasing habits that can improve the environment is gaining prominence. The use of perennial crops in food products will allow consumers to feel good about their purchase, and their role in supporting a sustainable agricultural system.

INTRODUCTION

•  Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE was carried out to visualize the protein distribution in all 19 samples.

•  Starch Pasting Properties. Determined by Rapid Visco Analyzer (RVA). •  Rheological Properties. Farinograph was used to determine the maximum water

absorption, dough development time, and dough stability (AACCI method 54-21.02). Kieffer method was used to determine the resistance to extension as well as extensibility of the dough using a texture analyzer.

•  Bread Making and Quality Parameters Measurement. AACCI method 10-09.01 was used to produce the bread samples. Bread volume measurement was done following the rapeseed displacement method (AACCI method 10-05.01). C-Cell Bread Imaging System was used for scanning of bread samples.

MATERIALS AND METHODS DISCUSSION

•  Our data indicated that there are some challenges for the use of IWG in baked products.

•  Compared to the wheat controls, IWG is higher in fiber and protein content, which makes it an attractive ingredient targeted toward health conscientious consumers. However, it is deficient the gluten component that is responsible for strength and elasticity5. Thus, IWG may pose challenges for use in baked goods.

•  Our findings demonstrated the need to investigate ways to enhance the protein functionality of IWG, for baked product applications, by varying constituents such as fiber content, and formulating at optimum conditions while using dough conditioners.

CONCLUSIONS

ABSTRACT

REFERENCES

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RESULTS

This project was supported through research grants provided by the Forever Green Initiative and Minnesota Department of Agriculture, as well as a gift fund by the Land Institute. North Dakota State University Wheat Quality and Carbohydrate Laboratory under Dr. Senay Simsek and USDA-ARS Cereal Crops Research Unit under Dr. Jae-Bom Ohm provided great help and collaboration with data generated. IWG lines were kindly provided by Dr. James Anderson and his research group from the Agronomy/Plant Genetics Department at the University of Minnesota.

ACKNOWLEDGEMENT

RESULTS

http://swbiodiversity.org/seinet/taxa/index.php?taxon=1288

Materials. 16 different IWG lines that are crossed based on their superior genetic characterization, a bulk species of IWG, along with two controls of wheat species (Hard Red Wheat (HRW) and Arapahoe) were grown and provided by the Agronomy/ Plant Genetics Department at the University of Minnesota.

• Protein Quantification. Determined by a nitrogen analyzer following the AOAC Dumas method. • Fat Quantification. Determined by Mojonnier method. • Ash Quantification. Determined by dry ashing method. • Moisture Quantification. Determined by vacuum oven - AACCI 44-40.01 method. • Total Starch Quantification. Determined by enzymatic assay with Megazyme kit. • Amylose/Amylopectin Ratio. Determined by size exclusion HPLC. • Total Dietary Fiber Quantification. Determined by enzymatic assay with Megazyme kit.

MATERIALS AND METHODS

Figure 7a and 7b. Dough resistance to extension and extensibility for all 19 samples, obtained through Kieffer method.

Figure 10. Bread pictures for all 19 samples taken by C-Cell Imaging System.

•  Investigate the types of interactions that stabilize the gluten network in IWG doughs. •  Monitor formation intermolecular β-sheet structure at different moisture contents,

various mixing temperatures, above glass transition, and stability during relaxation. •  Monitor dough strength upon addition of dough conditioners. •  Determine the effect of fiber content, or degree of refinement on gluten formation. •  Research different product applications that do not require rising properties during

baking, such as cookies, pancakes, breakfast cereal, and crackers.

FUTURE WORK

Figure 1. Protein content of 17 IWG samples and two wheat controls. All analyses were performed in triplicate and reported in ± standard deviation (SD).

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Figure 3. Total Starch content of 17 IWG samples and two wheat controls. All analyses were performed in triplicate and reported in ± standard deviation (SD).

Figure 4. SDS-PAGE visualization of gluten protein profiles of 19 samples. Lane 1: Molecular Weight Standard, Lane 2: Hard Red Wheat, Lane 3: Arapahoe, Lane 4: Bulk IWG, Lane 5: IWG L4-160, Lane 6: IWG L4-157, Lane 7: IWG L4-1, Lane 8: IWG L4-32, Lane 9: IWG L4-85.

Figure 2. Total Dietary Fiber content of 17 IWG samples and two wheat controls. All analyses were performed in duplicate and reported in ± standard deviation (SD).

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Figure 6. Farinograph Dough Stability Time Results of 17 IWG samples and two wheat controls. All analyses were performed in duplicate and reported in ± standard deviation (SD).

Figure 9. Bread Volume for all samples were performed in duplicate and reported in ± standard deviation (SD).

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74% 74% 78% 78% 77% 76% 77% 77% 76% 78% 75% 77% 76% 76% 77% 77% 78% 78% 76%

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67% 72% 73% 73% 76% 72% 75% 71% 74% 74% 72% 71% 74% 71% 72% 71% 72% 72% 70%

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Hard Red Wheat Arapahoe Bulk IWG IWG L4-1 IWG L4-3 IWG L4-29 IWG L4-32 IWG L4-57 IWG L4-72 IWG L4-84 IWG L4-85 IWG L4-103 IWG L4-105 IWG L4-139 IWG L4-154 IWG L4-157 IWG L4-159 IWG L4-160 IWG L4-172

Total Dietary Fiber Content (%)– Wet Basis SDF IDF

Figure 8. Starch pasting properties visualization of hard red wheat, bulk IWG, and IWG L4-1.

Figure 5. Farinogram of hard red wheat, bulk IWG, and IWG L4-1. All analyses were performed in duplicate.