Carrot alcohol insoluble residue

Sugar compositions (%) of carrot alcohol-insoluble residue (AIR), cell wall material (CWM) and CWM residue E... 

Preparation of the alcohol insoluble solids (AIS) The content of the can was drained and the carrot cubes were immediately frozen in hquid nitrogen, freeze-dried and milled. Carrot powder (ca. 10 g) was mixed with 200 ml 80% ethanol previously heated to 60°C. After filtration the residue was extracted with ethanol until the filtrate was colorless (5 times) and gave negative reaction with phenol-sulfuric acid test (Dubois et al., 1956). 

Carrot fiber, prepared as an alcohol-acetone insoluble residue of cell wall material, binds deoxycholate and chenodeoxycholate under physiological conditions with the release of protons. Removal of calcium pectate from this material by extraction with ammonium oxalate reduces the capacity of carrot fiber to bind bile acids. Calcium carboxymethyl cellulose exhibits similar binding activity, whereas free carboxymethyl cellulose shows no binding. Calcium pectate prepared from citrus pectin and dissolved in water was found to bind bile acids under conditions used with carrot fiber. These results suggest that binding occurs through formation of salt linkage between calcium pectate in the cell wall residue and a bile acid. 

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