Effect of pectin structure on protein utilization by growing rats.
The effect of pectins' molecular weight (MW) and degree of esterification (DE) on apparent digestibility (D), net protein utilization (NPU) and biological value (BV) of casein were tested. The pectins prepared differed in MW and DE respectively as follows: P-1 (180,000, 73%); P-2 (300,000, 28%); P-3 (60,000, 74%) and P-4 (75,000, 40%) and were fed as 10% of a purified diet containing 10% casein to growing male rats for 10 days. All preparations decreased D, with P-2 and P-4 showing milder effects than P-1 or P-3. Increased NPU was observed with pectins of low NW and/or DE, being significant only with P-4. Diets containing P-2, P-3 or P-4 had higher BV for casein than the pectin-free diet. Feeding these pectins in a protein-free diet did not cause a significant change in the rats' body N content. Thus, the increase in the BV of casein was attributed to improvements in the pattern of amino acids absorbed by rats fed pectins with low MW and/or low DE.
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002364:Caseins / Q000008:administration & dosage / Q000378:metabolism*; D002957:Citrus; D004043:Dietary Fiber / Q000494:pharmacology*; D004063:Digestion / Q000187:drug effects; D008297:Male; D008970:Molecular Weight; D009584:Nitrogen / Q000378:metabolism; D009753:Nutritive Value / Q000187:drug effects; D010368:Pectins / Q000494:pharmacology*; D051381:Rats; D013329:Structure-Activity Relationship
D002364:Caseins; D004043:Dietary Fiber; D010368:Pectins; D009584:Nitrogen