Abstract
This study was performed to investigate the effects of different kinds of dietary protein [plant protein ; Isolated Soy Protein(ISP), animal protein ; casein] on protein and lipid metabolism in rats fed with coffee and/or methionine in diet during four weeks of growing period after weanling. Forty male growing rats fo Sprague-Dawley strain, weighing 92.5$\pm$1.8g, were distributed into 8 groups by randomized complete block design, and fed diets containing 15% of protein by weight either as ISP or casein and 10% ofcalories as corn oil, supplemented with coffee and /or methionine for 4 weeks. Coffee were added at a concentration of 1.4% of diet as instant coffee, and methionine were added to ISP or casein diet to be 0.6% of diet as DL-methionine. Results were followed ; Body weight gain, F.E. R and P.E.R tanded to be higher in methionine added groups than non-methionine groups. The nitrogen content of feces was significantly higher in coffee groups than non-coffee groups, and tended to be higher in ISP groups than casein groups. but was not significantly different with or without methionine. thus, apparent protein digestilbity was significantly lower in coffee groups than non-coffee groups and was significantly lower in ISP groups than cesein groups, but was not significantly different with or without methionine. Total cholesterol content of serum tended to be higher in coffee groups than non-coffee groups, and tended to be lower in methionine groups than non-methionine groups.