Location: Functional Foods Research
2016 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
Equipment was obtained and procedures were adapted to analyze soluble and insoluble fiber, raffinose saccharides, and protein digestibility in various pulse flours before and after steam jet cooking and drum drying. Jet cooking was found to convert a portion of insoluble fiber to soluble fiber and slightly increase protein digestibility. Hot water solubility was increased and color and particle size were modified by the treatment. Experiments are in progress to determine the influence of pH and temperature on fiber solubilization and raffinose saccharide hydrolysis during steam jet cooking. Although coriander is a summer annual grown for use as an herb and spice, coriander seeds contain approximately 20% oil that is of current interest for its potential application in oleochemistry. However, the outer hull constitutes up to 50% of the overall seed weight and is considered a low-valued co-product obtained from coriander seed processing and represents a potential source of health-promoting food components. Hulls were found to have a total dietary fiber content of 86% consisting of insoluble (81%) and soluble (5%) dietary fiber, 8% protein, and 1% oil. Extrusion of the hulls shifted the insoluble and soluble dietary fiber ratios toward higher soluble fiber compositions. Further investigations are aimed to incorporate the hull fiber into savory snacks as a means to increase dietary fiber levels in these products. The effect of hydrocolloid replacement on the pasting properties of navy bean starch and on the properties of navy bean starch gels was examined. Native starches often perform poorly in food applications, but few studies have shown the effects of hydrocolloids on the properties of pulse starches. The effects of the hydrocolloids on pasting, water absorption, freeze-thaw stability, and textural properties of navy bean starch gels showed the possibility of improving navy bean starch and flour properties through the addition of hydrocolloids. Pulse based healthful beverages were explored. Emulsions made from blends of different proportions of soybeans and navy beans were prepared using traditional boiling and jet cooking. Emulsions with navy beans were found to be high in fiber, low in oil, and high in proteins and minerals. Increasing the content of navy beans reduced the soluble sugars in emulsions. Trypsin inhibitor value decreased with the use of thermal processing. The effect of complete replacement of wheat flour with whole pulse (navy bean, kidney bean, and lentil) flours on the quality of cookie dough and gluten-free and low-carbohydrate cookies was examined. Cookie dough characteristics and cookie quality of pulse (navy bean, kidney bean, and lentil) flours significantly differed among each other and in comparison to wheat flour. Lentil flour cookie dough was closest to wheat dough. Navy bean flour cookies had a spread factor close to wheat flour and navy bean cookies had a texture close to wheat flour cookies. Water to flour ratio in cookie dough affected both the dough and cookie characteristics. Whole pulse flours have a potential to replace wheat flours in gluten-free and low-carbohydrate cookies. Air classification is being investigated as a method for obtaining protein-enriched fractions of navy bean flours. An appropriate air classifier and mills have been identified and made available. Preliminary experiments have shown promise for protein shift in navy beans. The air classification process is being standardized for navy beans to increase the protein shift and the yield. Properties of films prepared from mixtures of poly(vinyl alcohol) (PVA) and starch complexes with fatty ammonium salts were determined. Addition of the starch complexes increase the stretchability (% elongation) of the films and imparted water resistance. Microscopy after iodine staining showed that no phase separation occurred during film drying, which provided evidence for ionic interactions between the slightly negatively charged PVA and the positively charged starch complexes. The water resistance (hydrophobicity) of paper as revealed by water contact angle was substantially increased by treatment with starch complexes with fatty ammonium salts followed by neutralization of the cationic complexes by rinsing with dilute base solution. Scanning electron microscopy revealed no visible deposition of starch within the cellulose fiber matrix despite the substantial modification of hydrophobicity. This simple process could replace many synthetic, non-biobased chemical treatments currently used for making paper water-resistant. Spray drying was investigated as an alternative to freeze-drying for amylose inclusion complexes prepared by steam jet cooking. Image processing and analysis techniques were used to determine temperature effects on the size of spray-dried particles. Further analysis showed that the complexes were not hydrolyzed or dissociated by the spray drying conditions. Amylose inclusion complexes are a potential delivery method for various types of desirable phytochemicals, phenolics, and bioactive compounds via molecular encapsulation. However, one of the greatest hindrances to successful application of amylose-ligand inclusion complexes is the lack of an economical and simple method for their preparation. Steam jet cooking was used to prepare amylose-fatty acid ester complexes as a method to complex ferulic acid, a bioactive molecule. Since ferulic acid is not capable of forming an inclusion complex with amylose, a fatty ferulic acid ester, octadecyl ferulate, was prepared and complexed with amylose via excess steam jet cooking. Steam jet cooking mixtures of high amylose starch and octadecyl ferulate was shown to be a simple method to prepare the corresponding amylose-octadecyl ferulate inclusion complexes.
Accomplishments
1. Pulse flour properties improved by steam jet cooking. Although it is widely known that beans and chickpeas are good sources of important nutrients such as protein, fiber, starch, and other substances like vitamins, minerals, and antioxidants, their use as a basis for food ingredients has not been growing as fast as the demand for more nutrient-dense foods. Whole bean flours have some negative properties that limit the degree to which they can be used to replace wheat flour in certain food classes such as gluten-free foods. In order to increase bean flour utilization, Agricultural Research Service researchers in Peoria, Illinois, determined the effects of steam jet cooking and drum drying as commercially scalable processing steps toward the goal of making bean flour more versatile and acceptable. The data obtained prove the concept that thermomechanical processing improves flour attributes, making this information useful to food product developers seeking more diverse opportunities for increased pulse flour utilization in a wider range of food systems.
2. Paper treated with starch complexes to impart water resistance. Current approaches for manufacturing paper with water resistance generally require chemical treatments and polymer coatings. Agricultural Research Service researchers in Peoria, Illinois, discovered that treatment of paper with corn starch complexed with a vegetable oil derivative renders the paper hydrophobic as measured by the contact angle with applied water droplets, which do not soak in. The amount of starch complex added is so small that it cannot be seen as a residue on the paper fibers viewed by scanning electron microscopy. The starch complexes can be easily made on a commercial scale with commonly available steam jet cooking equipment. This technology allows the use of a biobased and biodegradable material in place of synthetic, non-biodegradable plastic film coatings. A patent application has been filed and interest has been shown by paper manufacturing companies.
3. Rheological and textural properties of pulse starch gels. Pulses are well-recognized as an important food source and typically consumed as whole beans or flours, but there is also growing interest in the use of pulse protein concentrates and isolates, which leads to a coproduct of pulse starch. However, very little is known about the properties of pulse starch gels. Agricultural Research Service researchers in Peoria, Illinois, investigated the properties of starch gels from black beans, chickpeas, lentils, and navy beans. The properties of the starch gels were found to depend on the type of starch and the starch concentration. These results will be useful for utilizing pulse starch in food products, and show that further understanding of the relationship between starch composition and functional properties is required. Utilization of the starch coproduct will enhance the profitability of isolating protein from pulses to meet the increasing demand for protein supplements in foods and beverages.
None.
Review Publications
Kenar, J.A., Compton, D.L., Little, J.A., Peterson, S.C. 2016. Formation of inclusion complexes between high amylose starch and octadecyl ferulate via steam jet cooking. Carbohydrate Polymers. 140:246-252.
Byars, J.A., Singh, M. 2016. Rheological and textural properties of pulse starch gels. Starch. 68(7-8):778-784.
Finkenstadt, V.L., Felker, F.C., Fanta, G.F., Kenar, J.A., Selling, G.W., Hornback, K.J., Fisk, D.L. 2016. Extruded foams prepared from high amylose starch with sodium stearate to form amylose inclusion complexes. Journal of Applied Polymer Science. 133(13). doi: 10.1002/app.43251.
Fanta, G.F., Felker, F.C., Selling, G.W. 2016. Films prepared from poly(vinyl alcohol) and amylose-fatty acid salt inclusion complexes with increased surface hydrophobicity and high elongation. Starch. 68:1-11.
Hwang, H.-S., Singh, M., Lee, S. 2016. Properties of cookies made with natural wax-vegetable oil organogels. Journal of Food Science. 81(5):C1045-C1054.
Winkler-Moser, J.K., Singh, M., Rennick, K.A., Bakota, E.L., Jham, G., Liu, S.X., Vaughn, S.F. 2016. Detection of corn adulteration in Brazilian coffee (Coffea arabica) by tocopherol profiling and near-infrared (NIR) spectroscopy. Journal of Agricultural and Food Chemistry. 63(49):10662-10668.
Doll, K.M., Cermak, S.C., Kenar, J.A., Isbell, T.A., 2016. Synthesis and characterization of estolide esters containing epoxy and cyclic carbonate groups. Journal of the American Oil Chemists' Society. 93(8):1149-1155.
