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United States Department of Agriculture

Agricultural Research Service

2010 Annual Report

1a.Objectives (from AD-416)
The overall objective is to create more demand for the processing residues from sugar beets and citrus fruits by developing new valuable products and processes for their efficient and sustainable conversion into high quality food and non-food products.

1b.Approach (from AD-416)
(1)Prepare and evaluate new enzyme systems as tools to better understand and manipulate plant cell wall polysaccharide structure and function. (2) Extract by chemical and/or enzymatic means, isolate and characterize cell wall polysaccharides to determine molecular structure and physical properties in by-products of sugar beet and citrus processing for potential value added products. (3) Design new, value added personal care, biomedical and industrial products from cell wall polysaccharides in by-products of sugar beet and citrus processing. (4) Develop novel, value added biodegradable engineering materials by utilizing state-of-the-art extrusion processing. (5) Produce new prebiotic functional food and animal feed ingredients from citrus and sugar beet processing by-products.

3.Progress Report
Research on sugar beet cell wall polysaccharides was nearly completed. After individually removing and characterizing the acid and alkaline soluble polysaccharides from sugar beet pulp, the remaining insoluble residue was imaged by atomic force microscopy (AFM). AFM revealed long fibrous structures that were comparable in appearance to structures observed in potato cell wall fragments and identified by others as cellulose fibers. A soluble polysaccharide was obtained by treating the insoluble subtrate with monochloroacetate under basic conditions. The solubilized material was identified by various physical and chemical measurements as essentially carboxymethyl cellulose (CMC). For the first time the molecular structure of CMC was visualized by AFM. CMC is a polysaccharide widely used in industry. To date this research has demonstrated that three valuable polysaccharides can be sequentially extracted from sugar beet pulp.

Research on plant polysaccharide (PPS) derived matrices for colon-specific drug delivery, personal care and household applications continued. We prepared a series of hydrogel microparticles from pectin/zein and evaluated their physical, chemical, and biological activities in vivo (collaboration with scientists in Tajikistan). The preliminary results were summarized in a manuscript published by the Tajikistan Academy of Sciences demonstrating for the first time that pectin/zein-encapsulated drugs could be delivered to the colon following oral ingestion. The in vivo results also demonstrated the biocompatibility and non-toxicity of the pectin/protein microparticles.

Research on the synthesis of porous composite materials by extrusion-injection molding for engineering applications continued. Composites with porous structure were prepared from PLA and carbon nanotubes by melting-extrusion and injection-molding using a bench-top twin-crew extrusion. The mechanical properties of the composites were enhanced by the inclusion of the nanotubes; while thermal conductivity was able to be retained. This could be attributed to the porous structure of composites contributed by the nanotubes. Composite materials containing 95% sugar beet pulp and 5% poly(lactic acid) (PLA) were prepared by compression-heating method extruded in the presence of chemical cross-linkers. The mechanical properties of the resultant materials are similar to PLA.

Research on sugar beet and orange peel pectic oligosaccharides as potential function feed ingredients and prebiotic oligosaccharides continued. In vivo analysis of candidate prebiotics will be conducted once 20kg is produced in a commercial setting. Methods for enzymatic production of arabinose-rich pectic oligosaccharides are under investigation. See the subordinate project 1935-41000-068-04T annual report for further details. Hemicellulose oligosaccharides from citrus and cranberry with potential as prebiotics were further characterized by NMR.

1. New uses for pectin in controlled drug delivery. Orange peel is an under-utilized product of the citrus beverage industry that contains valuable polysaccharides such as pectin, yet pectin has not been produced in the U.S. for the past 15 years. Pectin has many uses besides its well known food gellation properties. ARS researchers in Wyndmoor, PA developed pectin-based drug delivery beads that incorporated a model drug, piroxicam, and tested them in rats. The delivery beads were constructed from pectin and corn protein or pectin with whey protein. The drug delivery efficacy was evaluated by monitoring the drug concentration in blood plasma of the rats post oral ingestion. The results of this study showed that pectin/protein beads are non-toxic, biocompatible, delivered the drug specifically to the colon, and the drug remained in the body for a prolonged time period. This is a key step to confirm the feasibility of the pectin use in colon-specific drug delivery. High value uses for plant polysaccharides such as these will be valuable for the U.S. citrus industry.

2. New functional food and biobased products from sugar beet pulp. New co-products of sugar production from sugar beets are necessary to improve the economics of this industry. Research on commercially valuable polysaccharides extracted from sugar beet pulp, such as pectin, alkaline soluble polysaccharides and carboxymethyl cellulose (CMC), demonstrated that new co-products can be generated. Sugar beet pectin is useful as an oil in water emulsifier in beverage food systems. ARS researchers in Wyndmoor, PA discovered that extensin is the protein associated with sugar beet pectin, and may be responsible for the emulsifying functional properties. Alkaline soluble polysaccharides have potential as bioactive food ingredient prebiotics. CMC is a well known food, consumer and biobased product ingredient. Sugar beet pulp is a more sustainable feedstock for CMC production compared to wood pulp. The results of this research can be used to add value to the U.S. sugar beet industry by sustainably producing commercially valuable polysaccharides.

Review Publications
Nunez, A., Fishman, M., Fortis, L.L., Cooke, P.H., Hotchkiss, A.T. 2009. Identification of extensin protein associated with sugar beet pectin. Journal of Agricultural and Food Chemistry. 57:10951-10958.

Gibson, G.R., Scott, K.P., Rastall, R.A., Touhy, K.M., Hotchkiss, A., Dubert-Ferrandon, A., Gareau,M., Murphy,E.F., Saulnier, D., Loh, G., Macfarlane, S., Delzenne, N., Ringel, Y., Kozianowski, G., Dickman, R., Lenoir-Wijnkoop, I., Walker, C., Buddington,R. 2010. Dietary prebiotics: Current status and new definition. Journal of Food Science and Technology Bulletin: Functional Foods 7:1-19.

Liu, L.S., Jin, Z.T., Coffin, D.R., Liu, C., Hicks, K.B. 2010. Poly (lactic acid) membranes containing bacteriocins and EDTA for inhibition of the surface growth of gram-negative bacteria. Journal of Applied Polymer Science. 117(1):486-492.

Liu, C., Liu, L.S., Latona, N.P., Ramos, M., Latona, R.J. 2010. The Use of Mixed Tocopherols to Improve UV and Heat Resistance of Leather. Journal of American Leather Chemists Association. 105(1):9-15.

Jiang, L., Liu, L.S., Chen, F., Qian, J., Jijun, H., Wolcott, M., Zhang, J. 2010. Reinforcing and Toughening Effects of Bamboo Pulp Fiber on Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Fiber Composites. Industrial and Engineering Chemistry Research. 49:572-577.

Khalikova, M.D., Rakhimov, E.F., Babokalonov, D.T., Muhidinov, Z.K., Liu, L.S. 2010. Biocompatibility of Pectin-Protein Gels and Microencapsulates: In Vivo Study on Rats. Journal of Academy of Sciences of the Republic of Tajikistan. 52(5):386-390.

Sharifova, Z.B., Usmanova, C.P., Muhidinov, Z.K., Bobokalonov, J.T., Gorshkova, L.M., Liu, L.S. 2009. Characterization of microparticles prepared by emulsion method from pectin and protein. Journal of Academy of Sciences of the Republic of Tajikistan. 135(2):72-77.

Farris, S., Schaich, K.M., Liu, L.S., Piergiovanni, L., Yam, K.L. 2009. Development of polyion-complex hydrogels as an alternative approach for the production of bio-based polymers for food packaging applications: A review. Trends in Food Science and Technology, 20:316-332.

Hotchkiss, A.T., Rastall, R., Gibson, G., Eliaz, I., Liu, L.S., Fishman, M. 2009. New bioactive and biobased product applications of pectin. Book Chapter In: Schols, H.A., Visser, R.G.F., Voragen, A.G.J., editors. Pectins and Pectinases. Wageningen, The Netherlands: Wageningen Academic Publisher. p. 305-312.

Last Modified: 5/29/2015
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