[Nutritional evaluation of protein quality of cassava leaf combined with casein by plastein reaction].
The present work was conducted to obtain a proteic product and to evaluate its biological value in order to be used for human and/or domestic animal consumption. Thus, it were used cassava leaves as a non conventional source of protein. It was produced a freeze-dried, fat-free and colourless proteic isolated from those leaves (CLPI). This was mixed with casein and after the mixture as enzymatically hydrolyzed and resynthesized (Plastein reaction) to obtain a precipitated (PP) and a soluble plastein (SP) fractions. The protein contents observed were 64.39% (PS), 61.36% (PP) and 51.97% (CLPI). Trypsin inhibitor activities values showed a 41% reduction in the PP fraction suggesting that the heat treatment used to inactivated the enzyme also inactiveted partially the inhibitor or the reduction was due to the casein dilution. The amino acid composition of the frations obtained showed values close to the standards established. It can be concluded:--the utilization of non-conventional source should be stimulated when the proteins from those sources have an amino acidic profile that allow them to be used as an amino acid supplementation in food with low level of essential amino acids;--the fractions obtained by the plastein reaction showed satisfactory protein contents and their amino acid profiles were comparable with the FAO/OMS/UNU (1985) recommendations;--the plastein reaction can be utilized in food processing, after industrial scale adaptation remove compounds responsible to bitter taste, fetidness and to discolour protein products.
Peluzio
M do C
Mdo C
Departamento de Nutrição e Saúde, Universidade Federal de Viçosa (UFV), MG, Brasil.
de Miranda
L C
LC
de Moraes
G H
GH
Peluzio
L E
LE
D000596:Amino Acids / Q000032:analysis; D002364:Caseins; D002614:Chelating Agents; D002365:Manihot; D009753:Nutritive Value; D018515:Plant Leaves; D014674:Plant Proteins, Dietary; D011492:Protein Hydrolysates
D000596:Amino Acids; D002364:Caseins; D002614:Chelating Agents; D014674:Plant Proteins, Dietary; D011492:Protein Hydrolysates; C011531:plastein