Browsing by Subject "camelina"

Now showing 1 - 4 of 4
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    Extraction, Modification, and Chemical Characterization of Protein and Dietary Fiber from Camelina Sativa
    (2018-07) Boyle, Claire
    Camelina sativa, a sustainable short-season cover crop, is an oilseed (35% oil) gaining interest due to the increasing global demand for sustainably sourced ingredients. Camelina provides numerous agricultural benefits—low production cost, low nitrogen requirements, drought resistance, cold weather tolerance, and short growing season—in addition to being high in protein (20%) and dietary fiber (30%), which are two of the fastest growing segments of the food ingredient market. In order to create functional, market-viable ingredients from camelina, the following need to be explored: efficient means of protein extraction, evaluation of protein functional properties, and chemical characterization of the dietary fiber constituents. The objectives of this study were as follows: (1) determine the impact of oil pressing conditions and protein extraction protocol on protein yield and content; (2) characterize structural differences in proteins extracted following salt precipitation and pH solubilization; (3) determine the impact of structure and enzymatic modification on the functionality of the different protein extracts; (4) isolate, quantify, and characterize the insoluble and soluble dietary fiber fractions of defatted camelina meal (DCM) prepared by two different oil pressing conditions. Protein extraction by pH solubilization and salt precipitation was tested and optimized. Camelina meal obtained from hot and cold press was further defatted by hexane and analyzed for protein content. Protein from DCM was extracted following degumming and pH solubilization at pH 12, separating non-protein material by centrifugation, acidifying the supernatant to pH 5 to precipitate out the protein, neutralizing and desalting. Protein from DCM was also extracted following salt precipitation, first by solubilizing the protein using 0.05 M phosphate buffer (pH 8, 1 M NaCl), followed by precipitation using 85% saturated ammonium sulfate solution, and desalting. To produce protein hydrolysates, extracted proteins were subjected to hydrolysis with Aspergillus oryzae protease by pH-stat methodology to a degree of hydrolysis less than 8%. Protein purity of the extracts was analyzed, and mass balances were tracked in order to evaluate extraction yields. The denaturation state, protein profile, and surface hydrophobicity of the protein extracts were determined using DSC, SDS-PAGE, and a fluorometric assay, respectively. Functionality was evaluated by determining protein solubility as well as emulsification, foaming, and gelation properties. Total dietary fiber (TDF) from DCM was determined following the AOAC method 2011.25, and three fractions —insoluble dietary fiber (IDF), soluble dietary fiber that precipitates in 78% ethanol (SDFP), and soluble dietary fiber that is soluble in 78% ethanol (SDFS) — were isolated preparatively. IDF and SDFP were analyzed spectrophotometrically for pectin content. The monomers of IDF and SDFP fractions were determined by alditol acetate formation and measured by GC-FID. Degree of pectin methylation (DM) of SDFP was determined by 1H NMR. The degree of polymerization (DP) of saccharides in the SDFS fraction (DP 2 – DP 7) was determined by liquid chromatography-ESI-mass spectrometry (LC-MS) using a ligand-exchange stationary phase and quantified by high performance anion exchange chromatography coupled with a pulsed amperometric detector (HPAEC-PAD). Disaccharides in DCM were differentiated and quantified spectrophotometrically following standard enzymatic assays. Compared to camelina protein concentrates (CPC) produced by alkaline pH extraction, CPC produced by salt extraction were less denatured and more functional. The functionality of the salt extracted CPC was comparable and sometimes better than that of soy protein isolate (SPI). Specifically, the solubility of the salt extracted CPC at pH 3.4 was significantly (P < 0.05) higher than that of SPI. Additionally, salt extracted CPC had significantly higher emulsification capacity and foaming capacity than SPI. On the other hand, the gelation property of CPC was inferior to that SPI, an observation attributed to the molecular size of camelina protein compared to SPI. Upon hydrolysis of CPC with Aspergillus oryzae protease, a limited benefit to solubility was noted at pH 7 post thermal treatment. TDF of DCM averaged 51.2% (45.3 – 49.1% IDF, 2.00 – 5.98% SDFP, 1.1 – 1.2% SDFS). The SDFS fraction was comprised mainly of stachyose and raffinose, which is in line with other Brassicaceae crops. The chief disaccharide present in DCM was verified to be sucrose (2.43 – 3.36%). Free glucose and fructose were also present in the SDFS fraction. Of the pectic polysaccharides measured in SDFP, low methoxyl pectin represented the major constituent, with a DM of 12.5 – 14.5%. Based on alditol acetate analysis, glucose was the main monomer in the IDF fraction. Other monosaccharides detected in the IDF fraction were xylose, arabinose, mannose, and galactose. The monosaccharide composition indicated the presence of cellulose, xyloglucans, galactomannans, and arabinoxylans in the IDF fraction. In SDFP, the monosaccharides rhamnose, arabinose, galactose, and mannose were evenly distributed. Monomer composition of the SDFP fraction indicated the presence of pectin and galactomannans. Results show that camelina meal contains a significant amount of protein and dietary fiber that can be isolated into functional ingredients. This is the first study to provide a comprehensive evaluation of protein and dietary fiber from camelina as potential alternatives to traditional ingredients. Further work is needed to understand how isolated camelina ingredients interact in various food matrices.
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    Forever Green Cookbook
    (Minnesota Institute for Sustainable Agriculture, 2021) Dooley, Beth
    Forever Green Cookbook Primary tabs These days, knowing where our food comes from and how it’s grown is more important than ever. Along with taste and nutrition, we want to be sure that it’s good for the land and wildlife, that it provides our farmers with a sustainable livelihood, and that good food is accessible to everyone. Such is the work of the Forever Green Initiative (FGI); a University of Minnesota and United States Department of Agriculture (USDA) Agricultural Research Service Program; which engages teams of experts in genomics, breeding, agronomics, soil health, and commercialization. Since its outset, FGI has placed equal importance on working hand in hand with the farmers, rural communities, food businesses, policy makers, and consumers who insist that healthy food, healthy rural communities, and a healthy environment are not mutually exclusive. Many of them are familiar pantry staples – grains, flour, oils, nuts, fruit, and vegetables. Today, these are all being grown in ways that connect recent advances in agricultural methods with ancient knowledge. Here are delicious ingredients for conscientious cooks. After all, “eating is an agricultural act.” – Wendell Berry.
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    Research from pod to pod: Harvest time optimization of shatter-resistant pennycress, camelina integration into the corn-soybean rotation, and communicating science via podcast.
    (2022-10) Cubins, Julija
    Corn (Zea mays L.) and soybean (Glycine max [L.] Merr) dominate the agricultural landscape in the Upper Midwest, but limits crop production to the summer months. There is a fallow period from late autumn through the spring that is associated with externalities such as nutrient loss and a lack of economically-viable crop production despite useable growing degree days during that period. Thus, pennycress (Thlaspi arvense L.) and camelina (Camelina sativa L.) are crops of interest for use during the corn-soybean fallow period. While both crops have been researched heavily for the past decade, questions about their production remain unanswered. Thus, the purpose of this dissertation is to further understand how pennycress harvest can be optimized for use within the corn-soybean rotation; observe the agronomic and economic dynamics when camelina is integrated into the corn-soybean rotation as a winter cash crop; further describe the effect of camelina in nutrient loss prevention over the typically-fallow period; and assess the role of camelina in the corn-soybean carbon cycle. All agronomic experiments were carried out over the 2019 and 2020 growing seasons. The pennycress experiment was conducted in Rosemount, MN, USA, while the camelina experiments were conducted in Morris and Rosemount, MN, USA. However, the research process does not end after data collection, analysis, and publication. For many scientists, there is a growing need to communicate findings with the general public rather than just to academic peers and industry and government stakeholders. This dissertation also explores the use of podcasting as a science communication medium though an experiential project, Hooked on Science.
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    Winter Camelina Response to Nitrogen for Double Cropping with Maize and Soybean in the Upper Midwest
    (2021-09) Gregg, Stephen
    Winter camelina [Camelina sativa (L.) Crantz] is a potential third crop that could be used to intensify maize [Zea mays L.]-soybean [Glycine max (L.) Merr.] rotations. It is considered a low-input crop, but previous studies have shown that it responds to added N. Yet, no formal fertilization studies have been conducted to determine optimum N levels for conditions in the upper Midwest. A study on camelina response to fertilizer N was conducted from fall 2018 to fall 2020 at three locations in Minnesota. The objectives were to: (i) determine the response of winter camelina to N and (ii) assess the effects of N fertilization strategy (fall-spring split or spring only application) on the productivity and quality of winter camelina. Data collected included grain yield, biomass, grain quality, and yield components. Grain yield and biomass were both affected by N in all locations and years, and both were higher in 2019 compared to 2020; among N rates, grain yield was significantly different, while no differences were found for biomass. Both, oil and protein content in grain were affected by N, with oil content generally declining with N rates increasing beyond 67 or 100 kg N ha-1, depending on location and year. Among yield components, branches and silicles per plant were significantly different among N rates; the former, along with the seed:shell ratio were significantly different in all years and locations. Based on the results of this study, a fertilization rate of 97 kg N ha-1 was found to maximize grain and oil yield of winter camelina in southwest Minnesota. Maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] in the upper Midwest are productive, but decades of these monocultures with winter fallow and late spring planting are in part responsible for loss in agroecological functioning as well as nitrogen (N) pollution in the agricultural communities and downstream. Winter camelina [Camelina sativa (L.) Crantz] is a third crop that could grow during this fallow period, but the environmental impacts of its N requirements are not well known. A study was conducted at three locations in Minnesota to determine the response of winter camelina do N. Five N rates (0, 33, 67, 100, 135 kg N ha-1) and two application timings (spring, and fall-spring split) were used to assess the N use efficiency (NUE) and residual N in winter camelina grown for grain yield from fall 2018 to fall 2020. Results showed higher NUE for fall-spring split application compared to spring only application. The agronomic efficiency (AE), internal efficiency (IE), and nitrogen recovery efficiency (NRE) tended to decrease with increasing N rates; AE generally decreased beyond 67 kg N ha-1 in most instances. Total N uptake ranged from 34 to 176 kg ha-1 across N rates. Residual soil N increased with increasing N rates, especially at the 15 cm depth. Based on declining NUE and increasing residual soil N with increasing N rates, an N rate between 33 to 67 kg N ha-1 could balance an efficient use of fertilizer with less environmental risk of higher N rates. Double cropping with winter camelina is a diversification option for the typical maize-soybean rotation in the upper Midwest, a strategy that promises environmental and economic benefits. Studies on double-cropping maize and soybean with non-fertilized- (Study 1) and nitrogen (N)-fertilized (Study 2) winter camelina were compared to assess the growth and yield, N, water use (WU), and water productivity (WP) of winter camelina in two locations in Minnesota. Study 1 was conducted from 2015–2017 in one location and the Study 2 was conducted from 2018–2020 in two locations, both studies in Minnesota. Yield of winter camelina was as much as six times higher in Study 2 compared to Study 1; averaged across treatments, Study 2 yielded 1157 kg ha-1 compared to 556 kg ha-1 from Study 2. In Study 1, oil and protein content ranged from 26.4 to 27.2% and 19.4 to 27.1% respectively. In Study 2, oil and protein content ranged from 31.7 to 35.9% and 14.9 to 20.8% respectively. Water use tended to follow similar trends between studies. Winter camelina average WU across cropping systems was similar between Study 1 and Study 2 (165 compared to 168 mm). Camelina WP was higher in Study 2 compared to Study 1, and ranged from 0.60 to 0.84 and 0.20 to 0.42 respectively. Fertilizer N was generally found to increase biomass, yield, WU, WP, and residual soil N in winter camelina double cropped with maize and soybean.