RESUMO
Most animal proteins are hypercholesrolimic and plant ones are not, therefore, searching for protein's amino acid composition role was observed. Biological trails of double six groups, 6 rats each, have been conducted for 4wks and 6wks of application. Groups fed on equalized 205 casein [C]dietary protein isolate namely wheat [W], soy [S], beef [B], pork [P], or turkey [T]. The assessment included blood total cholesterol [TC] and plasma lipoproteins [LDL, VLDL] and liver fat. Pork as animal protein and soy as plant protein have been found the most hypercholesterolemic. All rats fed animal protein diets had higher very low density lipoprotein [VLDL] than rats fed soy or wheat proteins. However, rats fed pork protein made the greatest LDL, VLDL, and TC; while it's HDL was low compared to those rats fed soy's, concurrently, liver index number of it remarkably reduced than the others. Biochemically, the most condensed amino acid [TAA] source was found in C followed by P, wherein the poorest one was W. Depending on the present data, animal proteins are more rich in containing essential amino acids [EAA], meanwhile, C represent the most balanced source for those followed with B and T. animal proteins make more than 84% casein' TAA, while plants, even soy, make less. Moreover, more than 75mg/g dry diet of animal AA are IAA and this were only 44 and 64 for W and S, respectively. This distinct AA soy protein profile comparing to both animals and plants might persist the biological deference. Moreover, it suppresses animal's in containing more cysteine, arginine and aspartic acids and contain much more Asp, His, Arg, Lys and much less Pro than W. surprisingly, P is the poorest animal protein source for EAA. The direct correlation between AA profile and atherogenicity is not clear. One explanation of this that wheat or soy diets have slower rate of digestibility with lower AA influx in blood stream and possible less interrupt lipid metabolism. This presumably occurred because of relatively lower amounts of EAA, e.g., lysine, Lucien, threonine, and tryptophan in wheat, or soy. Therefore, the next steps of those AA metabolisms may possess their negative efface on blood fat efflux by liver. It might be reasonable to conclude the following points: S then W less digestibility with remarkable indigestible proteins acts like dietary soluble fiber steadily lower cyclohepatic circulation to more blood LDL clearance, this may conjugate lower special AA influx in blood stream happened during feeding with animal proteins, meanwhile, some free AA, e.g., lysine, of fast influx in extracellular compartment can interfere lipids normal metabolism. Plant short peptides, i.e., three AA long or longer was acts as hormonal likes that may normally regulate lipids metabolism. In contrast, other animal short peptides, i.e., three AA long or fewer may acts as antagonistic hormonal likes that might up normally regulate lipids metabolism. Yet, the step of digestibility is the metabolic function ought to be further intensively studied in future