Location: Functional Foods Research
2019 Annual Report
Objectives
Objective 1: Enable new commercial processes for separating, concentrating, isolating, modifying, and improving functional components of oilseed press cakes and pulses alone and with other components for viable food, feed and non-food applications. Sub-objective 1.1: Select and acquire feedstocks; analyze and separate components. Sub-objective 1.2: Improve fractions and components by processing, chemical modification, enzymatic treatment, or combination with other materials.
Objective 2: Enable new commercial uses for components from oilseed press cakes and pulses in health-promoting food, feed and industrial applications. Sub-objective 2.1: Develop food applications for pulse components. Sub-objective 2.2: Develop non-food applications for oilseed press cake and pulse components.
Approach
Oilseed press cakes and pulse crops are two potentially valuable sources of functional food ingredients and biobased products from plant seed tissues which have not been fully exploited. New processing methods are critically needed in order to (1) identify new applications for currently low-value oilseed press cakes such as pennycress, coriander, and camelina, and (2) provide functional food ingredients from pulse crops in a form that facilitates incorporation into various food products while minimizing negative characteristics. In coordination with collaborating projects, pulse and press cake feedstocks will be obtained and their protein, starch, and fiber components separated by milling, extraction, or treatment with chemicals or enzymes. Thermo-mechanical processes such as steam jet cooking, steam explosion, and extrusion will be investigated as methods to separate, modify, or combine isolated components or remove undesirable components. Functional characteristics such as texture, particle size, microstructure, solubility, compatibility, and organoleptic properties will be determined and suitability for specific food and industrial applications will be investigated. The performance of prototype industrial products will be evaluated and the most efficient methods for the isolation of functional components determined. Anticipated biobased products include gums, adhesives, lubricants, thickeners, fibers, composite fillers, and coatings. Pulse fractions enriched in specific functional or nutritious ingredients will be incorporated into food formulations and evaluated for consumer acceptability. Successful utilization of these feedstocks will enhance the economic viability of the respective crops for farmers and thus provide agronomic benefits such as nitrogen fixation by legume crops and off-season cover crop benefits for oilseed producers.
Progress Report
Bean cooking water has been shown to contain water soluble components with potential food applications. To determine how thermomechanical processing affects the extraction efficiency or the composition profile of soluble pulse components, the supernatant fraction of bean flour extracted with water at room temperature, at cooking temperature, and with excess steam jet cooking will be compared with whole bean cooking water. Protein, fiber, sugar, and other components are being quantified and characterized, and potential uses for the solid phases are being evaluated based on their physical properties.
The particle size of pulse flours is known to affect the resistant starch content, since larger particles contain intact cells which inhibit starch digestion. However, the effect of particle size on protein digestibility and raffinose family oligosaccharide measurements has not been studied. Research is therefore being conducted on pulse flours of different particle sizes processed under three different moisture conditions: roasting (low moisture), baking (intermediate moisture), and pasting (high moisture). Treated flours are also being analyzed after in vitro gastric and intestinal digestion protocols. Microscopy has revealed differences in the presence and degree of swelling of starch granules and the persistence and extent of aggregation of intact cells in digested samples.
Fermentation has been used as a means for food preservation since ancient times. During fermentation sugars are hydrolyzed. Presence of oligosaccharides in pulses are one of the reasons for their low acceptability. Fermentation of pulse flours to hydrolyze their oligosaccharides was studied. Navy bean flour was fermented using anaerobic, natural fermentation to pH 4.5. A reduction in the oligosaccharides (raffinose, stachyose and verbascose) during fermentation was observed with their complete elimination at pH 4.5. Glucose and lactic acid contents increased with fermentation as a result of the hydrolysis of oligosaccharides. Fermentation of navy bean flour to pH 4.5 affected its pasting properties, decreasing the peak viscosity (19%) and final viscosity (22%). The pasting temperature of bean flour was not affected by fermentation. A decrease in slowly digestible starch and a corresponding increase in resistant starch was observed with fermentation. These results indicate that navy bean flour fermentation has potential for increasing the acceptability of pulses.
The effects of germination (sprouting) of navy beans, pinto beans and lentils on the starch and protein characteristics of the resulting pulse flours were determined. Composition, enzymatic characteristics and functional properties of sprouted pulse flours were measured to evaluate the effects of germination on carbohydrate and protein properties. The results confirmed that sprouting, a simple and cost-effective processing technique, was effective in reducing the oligosaccharides while not affecting the proximate composition of the sprouted flours. However, the effect of sprouting on functional properties was dependent on the pulse variety. Sprouting of pinto beans improved emulsion activity and stability, and reduced the resistant starch of the flours, while not affecting the protein solubility and pasting viscosity. The findings of this work have demonstrated that sprouted pulse flours are sufficiently different from flours of unsprouted beans that further studies of how they respond to additional treatments are warranted.
Stable flies (Stomoxys calcitrans L.) are a major problem in cattle production due to their negative effects on the health and productivity of the cattle. As an alternative to conventional fly repellant approaches such as DEET, a synthetic chemical with its own toxicity concerns, natural bio-based materials are being developed from coconut oil fatty acids. Mixtures of these fatty acids and their methyl esters were prepared by ARS scientists in Peoria, Illinois, and a sprayable starch composite delivery formulation was produced using jet-cooked starch. ARS collaborators at Lincoln, Nebraska, performed laboratory single-cage olfactometer bioassays which revealed that many of the active agents showed strong antifeedant and toxicity activities on stable flies. For the second year of a three-year field trial on cattle, 60 liters of a starch composite formulation were prepared in Peoria which performed well as a sprayable repellant treatment. These findings are important in the development of more powerful stable fly repellent formulations, not only with efficient antifeeding activity, but also possessing strong toxicity to kill flies as further contact occurs.
Alternatives to trans fats are needed since their use has been prohibited in the food marketplace. Formation of high quality oleogels has been investigated using mixtures of soybean oil with natural waxes including sunflower, candelilla, and beeswax. Phase contrast and polarized light microscopy was used to identify the morphological aspects of crystallization and structure formation in the oleogels.
The persistence of synthetic plastics in the environment has grown to be a major environmental threat, and efforts to replace plastic film materials with bio-based, biodegradable starch have increasing urgency. Starch nanoparticles produced by rapidly cooling jet-cooked amylose-fatty acid complexes were combined with a commercial emulsion of styrene-butadiene rubber (SBR) droplets and the properties of cast films were determined. The tensile properties of dry films were substantially improved with increasing starch nanoparticle content, allowing not only less SBR material to be used, but also a form of SBR with less styrene content.
The high surface area of aerogel beads produced with amylose-sodium palmitate complexes has drawn the interest of a major food company, who have provided proprietary starch samples from which critical point dried aerogels are being prepared for further investigation as a carrier agent.
Scanning electron microscopy was used to reveal the microstructure of pseudoflower formations produced by the pathogenic fungus Fusarium on a grass species (Xyris) in a novel pathogen-induced floral mimicry system.
Accomplishments
1. Gluten-free amaranth breads partially substituted with soybean, navy bean, and lupin flours. For millions of people with gluten-intolerance, finding food products that are healthy, nutritious, and tasty is a daunting task. Both amaranth and bean flours are higher in protein, minerals and vitamins than whole wheat flour along with gluten-free benefits. ARS scientists in Peoria, Illinois, investigated several gluten-free amaranth breads partially substituted with soybean, navy bean, and lupin flours. Volumes of breads using amaranth-soy 85:15 and 70:30 and amaranth-lupin 85:15 were larger than amaranth bread, and had less reductions compared to whole wheat bread. The amaranth bread and breads substituted with soybean, lupin and navy bean flours showed significantly higher or similar springiness compared to the whole wheat flour breads because of their high protein contents and water holding capacity. All amaranth breads substituted with soybean and lupin flours showed improved nutritional values and acceptable texture qualities compared to breads made from amaranth and whole wheat flours, respectively. The blending of amaranth with bean flours offers consumers and food producers a new way of developing gluten-free breads that have higher nutritional values and are healthier than current starch-based gluten-free breads currently on the market.
2. Starch composite for spray delivery of coconut fatty acid-based biting insect repellent on cattle. Biting insects cost the U.S. cattle industry more than $2.4 billion annually. A team of ARS researchers from Lincoln, Nebraska, and Peoria, Illinois, have recently identified an effective bio-based biting insect repellent for the cattle industry from coconut oil fatty acids. However, field studies examining longevity of antifeeding activity and animal safety of sprayable formulations containing these fatty acids are needed. ARS researchers from Peoria, Illinois, have formulated the coconut fatty acids into an easily sprayable aqueous starch composite that has been scaled to 60 liters. Topical application of a 6% coconut fatty acid formulation showed over 96-hours of protection on cattle against biting flies, which are the longest repellency times observed for any natural product. The material is currently undergoing the second of a three-year farm animal evaluation against biting flies at a cattle research farm in Nebraska. This sustainable bio-based system provides an alternative to DEET, a synthetic chemical which persists in the environment and poses health risks. This new delivery system technology could be adapted by other livestock animal producers, the pet industry, and in other public health applications for preventive insect repellant protection.
3. Starch complex for improved retention of flavor compounds in foods. The protection and delivery of sensitive flavor compounds in food applications are of importance since their protection can improve food quality, flavor, and extend the shelf life of products. ARS researchers from Peoria, Illinois, in collaboration with University of Illinois researchers examined the protection of an unstable popcorn-like aroma compound using starch complexation. Starch-flavor complexes were successfully prepared and characterized using various instrumental techniques. The complexes retained the flavor compound for up to two weeks longer compared to the un-complexed flavor compound that underwent rapid loss within 30 minutes. Experiments have demonstrated that the flavor compounds could be stabilized by amylose complex formation. This technology provides a potentially useful advantage to reduce food waste and provide more value to food producers.
Review Publications
Paulsen, M.R., Singh, M., Singh, V. 2018. Measurement and maintenance of corn quality. In: Serna-Saldivar, S.O., editor. Corn: Chemistry and Technology. 3rd edition. Cambridge, MA: Elsevier. p. 165-211.
Liu, S., Chen, D., Xu, J. 2019. Characterization of amaranth and bean flour blends and the impact on quality of gluten-free breads. Journal of Food Measurement and Characterization. 13(2):1440-1450. https://doi.org/10.1007/s11694-019-00060-4.
Felker, F.C., Fanta, G.F., Peterson, S.C. 2019. Glucose-reduced silver nanoparticles prepared with amylose-sodium palmitate inclusion complexes and their dry storage and reconstitution. Starch. https://doi.org/10.1002/star.201800238.
Hay, W.T., Fanta, G.F., Felker, F.C., Peterson, S.C., Skory, C.D., Hojilla-Evangelista, M.P., Biresaw, G., Selling, G.W. 2019. Emulsification properties of amylose-fatty sodium salt inclusion complexes. Food Hydrocolloids. 90:490-499. https://doi.org/10.1016/j.foodhyd.2018.12.038.
Zhu, J.J., Cermak, S.C., Kenar, J.A., Brewer, G., Haynes, K., Boxler, D., Baker, P., Wang, D., Wang, C., Li, A.Y., Xue, R., Shen, Y., Wang, F., Agramonte, N.M., Bernier, U.R., Filho, J., Ligia, B., Taylor, D.B., Friesen, K.M. 2018. Better than DEET repellent compounds derived from coconut oil. Nature Scientific Reports. 8:14053. https://doi.org/10.1038/s41598-018-32373-7.
Hausch, B.J., Little, J.A., Kenar, J.A., Cadwallader, K.R. 2018. Starch-flavor complexation applied to 2-acetyl-1-pyrroline. Journal of Agricultural and Food Chemistry. 66(44):11718-11728. https://doi.org/10.1021/acs.jafc.8b04133.
Jackson, M.A., Price, N.P., Blackburn, J.A., Peterson, S.C., Kenar, J.A., Haasch, R., Chen, C. 2019. Partial hydrodeoxygenation of corn cob hydrolysate over palladium catalysts to produce 1-hydroxy-2-pentanone. Applied Catalysis A: General. 577:52-61. https://doi.org/10.1016/j.apcata.2019.03.019.
Felker, F.C., Kenar, J.A., Byars, J.A., Singh, M., Liu, S.X. 2018. Comparison of properties of raw pulse flours with those of jet-cooked, drum-dried flours. LWT - Food Science and Technology. 96:648-656. https://doi.org/10.1016/j.lwt.2018.06.022.
