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United States Department of Agriculture

Agricultural Research Service

Wilbur W. Widmer (Bill)

Research Chemist


Publications (Clicking on the reprint icon Reprint Icon will take you to the publication reprint.)
Characterization of molecular structural changes in pectin during juice cloud destabilization in frozen concentrated orange juice - (Peer Reviewed Journal)
Galant, A.L., Widmer, W.W., Luzio, G.A., Cameron, R.G. 2014. Characterization of molecular structural changes in pectin during juice cloud destabilization in frozen concentrated orange juice. Food Hydrocolloids Journal. 41:10-18.
Compositional and Structural Characterization of Pectic Material from Frozen Concentrated Orange Juice - (Peer Reviewed Journal)
Galant, A.L., Luzio, G.A., Widmer, W.W., Cameron, R.G. 2014. Compositional and Structural Characterization of Pectic Material from Frozen Concentrated Orange Juice. Food Hydrocolloids Journal. 35:661-669.
A modified grapefruit juice eliminates two compound classes as major mediators of the Grapefruit Juice-Fexofenadine Interaction: an In Vitro-In Vivo 'Connect' - (Peer Reviewed Journal)
Won, C.S., Lan, T., Vandermolen, K.M., Dawson, P.A., Oberlies, N.H., Widmer, W.W., Scarlett, Y.V., Paine, M.F. 2013. A modified grapefruit juice eliminates two compound classes as major mediators of the Grapefruit Juice-Fexofenadine Interaction: an In Vitro-In Vivo 'Connect'. Journal of Clinical Pharmacology. 53(9):982-990.
Use of carnauba based carrier for copper sprays reduces infection by Xanthomonas citri subsp. citri and Diaporthe citri in Florida commercial grapefruit groves - (Peer Reviewed Journal)
Narciso, J.A., Widmer, W.W., Ritenour, M.A., Ference, C.M., Diaz, R. 2012. Use of carnauba based carrier for copper sprays reduces infection by Xanthomonas citri subsp. citri and Diaporthe citri in Florida commercial grapefruit groves. Agricultural Sciences. 3(7):962-970.
Extraction and recovery of pectic fragments from citrus processing waste for co-production with ethanol - (Peer Reviewed Journal)
Grohmann, K., Cameron, R.G., Kim, Y., Widmer, W.W., Luzio, G.A. 2012. Extraction and recovery of pectic fragments from citrus processing waste for co-production with ethanol. Journal of Chemical Technology & Biotechnology. DOI: 10.1002/jctb.3859.
Characterization of Pectin from Citrus sinensis (Sweet Orange) Juice - (Abstract Only) - (01-Apr-12)
Effect of extraction method on quality of orange juice: hand-squeezed, commercial-fresh squeezed and processed - (Peer Reviewed Journal)
Baldwin, E.A., Bai, J., Plotto, A., Cameron, R.G., Luzio, G.A., Narciso, J.A., Manthey, J.A., Widmer, W.W., Ford, B.L. 2012. Effect of extraction method on quality of orange juice: hand-squeezed, commercial-fresh squeezed and processed. Journal of the Science of Food and Agriculture. 92:2029-2042.
Effect of copper hydroxide sprays for citrus canker control on wild type Escherichia coli - (Peer Reviewed Journal)
Narciso, J.A., Ference, C.M., Ritenour, M., Widmer, W.W. 2012. Effect of copper hydroxide sprays for citrus canker control on wild type Escherichia coli. Letters in Applied Microbiology. 54:108-111.
Effect of maturity, processing and storage on the furanocoumarin composition of grapefruit and grapefruit juice - (Peer Reviewed Journal)
Cancalon, P.F., Barros, S.M., Haun, C., Widmer, W.W. 2011. Effect of maturity, processing, and storage on the furanocoumarin composition of grapefruit and grapefruit juice. Journal of Food Science. 76(4):C543-548.
The effect of grapefruit juice on drug disposition - (Peer Reviewed Journal)
Hanley, M.J., Cancalon, P., Widmer, W.W., Greenblatt, D.J. 2011. The effect of grapefruit juice on drug disposition. Expert Opinion on Drug Metabolism & Toxicology. 7(3):267-286.
New enzymes for hydrolysis and fermentation of citrus waste - (Abstract Only) - (16-Oct-10)
Analysis of biomass sugars and galacturonic acid by gradient anion exchange chromatography and pulsed amperometric detection without post-column addition - (Peer Reviewed Journal) - (11-Oct-10)
An improved method for analysis of biomass sugars and galacturonic acid by anion exchange chromatography - (Peer Reviewed Journal)
Widmer, W.W. 2011. Analysis of biomass sugars and galacturonic acid by gradient anion exchange chromatography and pulsed amperonmetric detection without post-column addition. Biotechnology Letters. 33:365-368.
Citrus waste stream utilization - (Abstract Only) - (25-Feb-10)
Ethanol and other products from citrus processing waste - (Abstract Only) - (25-Feb-10)
Pretreatment effects on orange processing waste for making ethanol by simultaneous saccharification and fermentation - (Peer Reviewed Journal)
Widmer, W., Zhou, W., Grohmann, K. 2010. Pretreatment effects on orange processing waste for making ethanol by simultaneous saccharification and fermentation. Bioresource Technology. 101:5242-5249.
The effect of Dry matter content on the simultaneous saccharification and fermentation of citrus processing waste - (Proceedings)
Zhou, W., Widmer, W., Grohmann, K. 2009. The effect of dry matter content on the simultaneous saccharification and fermentation of citrus processing waste. Proceedings of Florida State Horticultural Society. 122:316-318.
Improved analysis of simple sugars and galacturonic acid in hydrolyzed citrus waste - (Abstract Only)
Widmer, W. 2009. Improved analysis of simple sugars and galacturonic acid in hydrolyzed citrus waste. Subtropical Technology Conference Proceedings. 60:13-14.
Converting citrus waste to ethanol and other co-products - (Proceedings)
Widmer, W.W., Zhou, W., Grohmann, K. 2009. Converting citrus waste to ethanol and other co-products. Transactions 2009 Citrus Engineering Conference Proceedings, A.S.M.E. 55:18-25.
Simultaneous saccharification and fermentation of orange processing waste to ethanol using Kluyveromyces marxianus - (Peer Reviewed Journal)
Widmer, W.W., Narciso, J.A., Grohmann, K., Wilkins, M.R. 2009. Simultaneous saccharification and fermentation of orange processing waste to ethanol using Kluyveromyces marxianus. Biological Engineering (ASABE). 2(1):17-29.
Developments in ethanol production from citrus peel waste - (Peer Reviewed Journal)
Zhou, W., Widmer, W., Grohmann, K. 2008. Developments in ethanol production from citrus peel waste. Proceedings of Florida State Horticultural Society. 121:307-310.
Biosorption properties of citrus peel derived oligogalacturonides, enzyme-modified pectin and peel hydrolysis residues - (Peer Reviewed Journal)
Cameron, R.G., Luzio, G.A., Widmer, W.W., Iqbal, M. 2008. Biosorption properties of citrus peel derived oligogalacturonides, enzyme-modified pectin and peel hydrolysis residues. Proceedings of Florida State Horticultural Society. 121:311-314.
Nutrient composition and flavonoid content of orange fermentation residues - (Abstract Only)
Widmer, W.W. 2008. Nutrient composition and flavonoid content of orange fermentation residues. Subtropical Technology Conference Proceedings. 59:16.
Technical and economic assessments of ethanol production from citrus peel waste - (Abstract Only)
Zhou, W., Widmer, W., Grohmann, K. 2008. Technical and economic assessments of ethanol production from citrus peel waste. Florida State Horticultural Society Meeting. Paper No. HP22.
Biosorption properties of citrus peel derived oligogalacturonides, enzyme-modified pectin and peel hydrolysis residues - (Abstract Only)
Cameron, R.G., Luzio, G.A., Widmer, W.W. 2008. Biosorption properties of citrus peel derived oligogalacturonides, enzyme-modified pectin and peel hydrolysis residues. Florida State Horticultural Society Meeting. Paper No. HP23.
Further characterization of a furanocoumarin-free grapefruit juice drug disposition: Studies with cyclosporine - (Peer Reviewed Journal)
Paine, M.F., Widmer, W.W., Pusek, S.N., Beavers, K.L., Criss, A.B., Snyder, J., Watkins, P.B. 2008. Further characterization of a furanocoumarin-free grapefruit juice drug disposition: Studies with cyclosporine. American Journal of Clinical Nutrition. 87:863-871.
Economic analysis of ethanol production from citrus peel waste - (Peer Reviewed Journal)
Zhou, W., Widmer, W., Grohmann, K. 2007. Economic analysis of ethanol production from citrus peel waste. Proceedings of Florida State Horticultural Society. 120:310-315.
Simultaneous saccharification and fermentation of citrus peel waste by Saccharomyces cerevisiae to produce ethanol - (Peer Reviewed Journal)
Wilkins, M.R., Widmer, W.W., Grohmann, K. 2007. Simultaneous saccharification and fermentation of citrus peel waste by Saccharomyces cerevisiae to produce ethanol. Process Biochemistry. 42(12):1614-1619.
Economic analysis of ethanol production from citrus peel waste - (Abstract Only)
Zhou, W., Widmer, W.W. 2007. Economic analysis of ethanol production from citrus peel waste. Subtropical Technology Conference Proceedings. 58:17.
Ion binding capacity of enzyme modified citrus peel and pectin - (Abstract Only)
Cameron, R.G., Luzio, G.A., Widmer, W.W., Iqbal, M. 2007. Ion binding capacity of enzyme modified citrus peel and pectin. Subtropical Technology Conference Proceedings. 58:19.
Enzymatic Hydrolysis of Grapefruit Peel to Produce Ethanol and Other Products - (Proceedings)
Wilkins, M.R., Widmer, W.W., Grohmann, K. 2007. Enzymatic hydrolysis of grapefruit peel to produce ethanol and other products. Proceedings of American Society of Agricultural Engineers [serial online]. Paper No. 057047. Available: http://asae.frymulti.com/request.asp?search=1&JID=5&AID=19664&CID=tfl2005&v=&i=&T=1
Economic analysis of ethanol production from citrus peel waste - (Abstract Only)
Zhou, W., Widmer, W., Grohmann, K. 2007. Economic analysis of ethanol production from citrus peel waste. Florida State Horticultural Society Meeting. Abstract No. HP22.
Ethanol from orange processing waste - (Abstract Only)
Widmer, W.W., Grohmann, K. 2007. Ethanol from orange processing waste. National Meeting of Institute of Food Technologists/Food Expo. Presentation No. 140-09.
The isolation of minor-occurring furanocoumarins in grapefruit and analysis of their inhibition of cyp 3a4 and p-glycoprotein transport of talinolol from caco-2 cells - (Peer Reviewed Journal)
Manthey, J.A., Myung, K., Mertens-Talcott, S., Derendorf, H., Butterweck, V., Widmer, W. 2006. The isolation of minor-occurring furanocoumarins in grapefruit and analysis of their inhibition of CYP 3A4 and p-glycoprotein transport of talinolol from caco-2 cells. Proceedings of Florida State Horticultural Society. 119:361-366.
Analysis of polymethoxylated flavones in citrus products by direct injection and in-line trace enrichment - (Abstract Only)
Widmer, W.W. 2006. Analysis of polymethoxylated flavones in citrus products by direct injection and in-line trace enrichment. Subtropical Technology Conference Proceedings. 57:22-23.
Effect of D-Limonene on the Fermentation of Citrus Peel Waste - (Proceedings)
Wilkins, M.R., Grohmann, K., Widmer, W.W. 2006. Effect of d-limonene on the fermentation of citrus peel waste. Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)[serial online]. Paper No. 067007. Availble: http://asae.frymulti.com/request.asp?search=1&JID=5&AID=21005&CID=por2006&v=&i=&T=1
Hydrolysis of Grapefruit Peel Waste with Cellulase and Pectinase Enzymes - (Peer Reviewed Journal)
Wilkins, M.R., Widmer, W.W., Grohmann, K., Cameron, R.G. 2006. Hydrolysis of grapefruit peel waste with cellulase and pectinase enzymes. Bioresource Technology. 98:1596-1601.
A “furanocoumarin-Free” Grapefruit Juice Establishes Furanocoumarins As the Mediators of the Grapefruit Juice-Felodipine Juice Interaction Reprint Icon - (Peer Reviewed Journal)
Paine, M.F., Widmer, W.W., Pusek, S.N., Beavers, K.L., Criss, A.B., Brown, S.S., Thomas, B.F., Watkins, P.B. 2006. A "furanocoumarin-free" grapefruit juice establishes furanocoumarins as the mediators of the grapefruit juice-felodipine interaction. American Journal of Clinical Nutrition. 83:1097-1105.
Effect of Seasonal Variation on Enzymatic Hydrolysis of Valencia Orange Peel Reprint Icon - (Peer Reviewed Journal)
Wilkins, M.R., Widmer, W.W., Cameron, R.G., Grohmann, K. 2006. Effect of seasonal variation on enzymatic hydrolysis of Valencia orange peel. Proceedings of Florida State Horticultural Society. 118:419-422.
Healthy Products from Citrus Juice Processing Waste Streams - (Abstract Only)
Widmer, W.W., Manthey, J.A., Cameron, R.G. 2006. Healthy products from citrus juice processing waste streams. American Chemical Society National Meeting. Paper No. AGFD18.
Citrus Waste to Ethanol and Other Byproducts: An Update - (Abstract Only)
Widmer, W.W., Wilkins, M.R., Grohmann, K. 2005. Citrus waste to ethanol and other byproducts: an update. Subtropical Technology Conference Proceedings. 56:15.
In Vitro Determination of the Prebiotic Properties of Oligosaccharides Derived from An Orange Juice Manufacture Byproduct Stream - (Peer Reviewed Journal)
Manderson, K., Pinart, M., Tuohy, K.M., Grace, W.E., Hotchkiss, A.T., Widmer, W.W., Yadav, M.P., Gibson, G.R., Rastall, R.A. 2005. In vitro determination of the prebiotic properties of oligosaccharides derived from an orange juice manufacture byproduct stream. Applied and Environmental Microbiology. 71:8383-8389.
Furanocoumarin Variation in Four Grapefruit Varieties with Respect to Maturity - (Abstract Only)
Widmer, W.W., Stinson, W., Dou, H., Haun, C. 2005. Furanocoumarin variation in four grapefruit varieties with respect to maturity. National Meeting of Institute of Food Technologists/Food Expo. Paper No. 104-5.
One tangerine/grapefruit hybrid (tangelos) contains trace amounts of furanocoumarins at a level too low to be associated with grapefruit/drug interactions - (Peer Reviewed Journal)
Widmer, W.W. 2005. One tangerine/grapefruit hybrid (tangelos) contains trace amounts of furanocoumarins at a level too low to be associated with grapefruit/drug interactions. Journal of Food Science. 70:C419-C422.
Effect of Seasonal Variation on Enzymatic Hydrolysis of Valencia Orange Peel - (Abstract Only) - (02-Mar-05)
Variation in Furanocoumarin Content and New Furanocoumarin Dimers in Commercial Grapefruit (Citrus Paradisi, MARCF.) Juices - (Peer Reviewed Journal)
Widmer, W.W., Haun, C. 2005. Variation in furanocoumarin content and new furanocoumarin dimers in commercial grapefruit (Citrus paradisi, marcf.) juices. Journal of Food Science. 70(4):C307-312.
Flash Extraction of Pectin - (Abstract Only)
Hotchkiss, A.T., Widmer, W.W., Fishman, M.L. Flash extraction of pectin. Abstract for American Chemical Society 229th National Meeting, San Diego, CA, March 13-19, 2005. Cell 96.
Enzymatic Hydrolysis of Grapefruit Peel to Produce Ethanol and Other Products - (Abstract Only) - (26-Nov-04)
Furanocoumarin Variation in Four Grapefruit Varieties with Respect to Maturity - (Abstract Only)
Widmer, W.W., Stinson, W., Dou, H., Haun, C. 2004. Furanocoumarin variation in four grapefruit varieties with respect to maturity. Subtropical Technology Conference Proceedings. 55:26-27.
Health Benefits of Citrus Polysaccharides - (Abstract Only)
Widmer, W.W. 2004. Health benefits of citrus polysaccharides. American Chemical Society National Meeting. Paper No. AGFD 143.
Do Furanocoumarins Mediate the Grapefruit Juice-Cyclosporine Interaction in Humans in Vivo? - (Abstract Only) - (30-Apr-04)
Effects of Processing Parameters on Furanocoumarin Content in Grapefruit Juice - (Abstract Only)
Widmer, W.W., Barros, S.M., Smith, J. 2003. Effects of processing parameters on furanocoumarin content in grapefruit juice. Subtropical Technology Conference Proceedings. 54:39.
A Furanocoumarin-Free Grapefruit Juice Does Not Alter the Oral Pharmacokinetics of Felodipine - (Abstract Only) - (05-Jun-03)
Dietary Fiber and Other Products from Complex Carbohydrates in Citrus Processing Waste - (Abstract Only)
WIDMER, W.W. DIETARY FIBER AND OTHER PRODUCTS FROM COMPLEX CARBOHYDRATES IN CITRUS PROCESSING WASTE. ANNUAL MEETING OF THE INSTITUTE OF FOOD TECHNOLOGISTS. 2003. p. 46. ABSTRACT NO. 19-6.
Furanocoumarin Content in Commercial Grapefruit Juice and Absence in Grapefruit/tangerine Hybrids (Tangelos) - (Abstract Only) - (16-May-03)
The Grapefruit Juice Effect: Grapefruit Juice and Drug Metabolism a Dynamic Relationship - (Abstract Only) - (16-May-03)
Dietary Fiber Content in Fresh Citrus - (Proceedings)
Widmer, W.W. Dietary fiber content in fresh citrus. Proceedings of the Florida State Horticultural Society. 2002. v. 115. p. 301-303.
Last Modified: 12/13/2011