Bioactive properties of pectic oligosaccharides from sugar beet and Valencia oranges

CARB 114

Arland T. Hotchkiss Jr., arland.hotchkiss@ars.usda.gov1, Kirstie Manderson, k.manderson@reading.ac.uk2, Kieran M. Tuohy, k.m.tuohy@reading.ac.uk2, Wilbur W. Widmer, wwidmer@citrus.usda.gov3, Alberto Nunez, alberto.nunez@ars.usda.gov4, Glenn R. Gibson, g.r.gibson@reading.ac.uk2, and Robert A. Rastall, r.a.rastall@reading.ac.uk2. (1) Crop Conversion Science and Engineering, U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038-8551, (2) School of Food Biosciences, The University of Reading, PO Box 226, Whiteknights, Reading, RG6 6AP, United Kingdom, (3) Citrus & Subtropical Products Laboratory, USDA/ARS/SAA, 600 Avenue S Northwest, Winter Haven, FL 33881, (4) Core Technologies, ERRC, USDA-ARS, 600 East Mermaid Lane, Wyndmoor, PA 19038, Wyndmoor, PA 19038
The fermentation profile of sugar beet pulp and pectic oligosaccharides (POS) derived from sugar beet and Valencia oranges were determined in vitro. The Valencia orange POS consisted of the arabinogalactan pectic side chains and xyloglucan. However, the sugar beet POS consistsed of homogalacturonan oligosaccharides, rhamnogalacturonan I and II as well as the arabinogalactan pectic side chains and minor amounts of xyloglucan. Temperature and pH controlled, stirred anaerobic fecal batch cultures were used and fermentation end products and bacterial population changes were determined. POS from Valencia oranges was found to be bifidogenic after 24 hours fermentation and all novel test substrates caused an increase in acetate, butyrate and propionate concentrations. POS substrates were investigated for their ability to neutralise Shiga-like toxins from Escherichia coli O157:H7 and POS from Valencia oranges was able to neutralise the effects of the toxins at 10µgml-1. During this study, POS from sugar beet was found to inhibit the growth of the colon cancer cell line HT29 and on further investigation a dose response was found. This finding may have implications for dietary protection against colon cancer.
 

Biological Applications of Carbohydrates
8:30 AM-12:10 PM, Thursday, March 29, 2007 McCormick Place North -- Room N226, Level 2, Oral

Division of Carbohydrate Chemistry

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007