|
Sergei Yu. Zaitsev
Changes
in the amino acid composition of gelatin after treatment of bovine collagen
with enzyme preparations
Abstract
Abstract. Recently, more attention has been paid to the study of the amino
acid composition of gelatins, which is associated with the quality of the
corresponding gels as intermediates for human and animal nutrition. In a brief
review, a modification of the general method of acid extraction of collagens
for the preparation of gelatins using enzymes (such as papain, actinidin, and
others) is considered and the corresponding changes in the amino acid
composition of gelatins are discussed. It is clear that there are changes in
the content of glycine in gelatins from any collagens, but in all cases the
content of glycine is about a third of the content of all amino acids (as in
the original collagens). It is important that the content of imino acids (the
sum of proline and hydroxyproline, which largely determines the properties of
gels) in gelatins from any collagens with the use of all the studied enzymes is
much higher than without them. In addition, the content of imino acids in
gelatin from the bovine skin of cows with the use of any enzymes is
significantly higher than in gelatins from the skin of pigs and fish. This
holds true for other key “proteinogenic” amino acids as well. The reverse trend
is observed only for a few amino acids: serine, threonine, tyrosine,
phenylalanine, the content of which is low in gelatins from any collagens.
Key words: amino acid composition, gelatin, collagen, enzyme preparations,
animal biochemistry
Copyright (C) Chemistry Dept., Moscow State University, 2002
|
|
