8.31: summary:
. I first got interested in gelatin from Dr.Peat
(Ray Peat Ph.D. endocrinology/gelatin 2009)
who said that combining it with meat
made for a meal that was most like
what was found in nature:
carnivores eat the whole thing,
not just the meat .
. gelatin is a mixture of peptides and proteins
produced by partial hydrolysis of collagen
extracted from the boiled bones, connective tissues,
organs and some intestines of animals such as
domesticated cattle, and pigs.
Gelatin is unusually high in glycine and proline
while lacking certain essential amino acids
It contains no tryptophan and is deficient in
isoleucine, threonine, and methionine:
. glycine 21%, proline 12%, hydroxyproline 12%,
glutamic acid 10%, alanine 9%, arginine 8%,
aspartic acid 6%, lysine 4%, serine 4%,
leucine 3%, valine 2%, phenylalanine 2%,
threonine 2%, isoleucine 1%, hydroxylysine 1%,
traces of methionine, histidine, and tyrosine .
. vegetarian gelatins use agar-agar (a seaweed),
carrageenan, pectin, konjak, and guar gum;
these include fiber or sugars (some toxic)
rather than special forms of protein .
Pectins are a family of complex polysaccharides
that contain 1,4-linked α-D-galactosyluronic acid residues.
Three pectic polysaccharides have been isolated:
# Homogalacturonans
# Substituted galacturonans
# Rhamnogalacturonans
Homogalacturonans are linear chains of
α-(1-4)-linked D-galacturonic acid.[4]
Substituted galacturonans are characterized by the presence of
saccharide appendant residues (such as
D-xylose or D-apiose in the respective cases of
xylogalacturonan and apiogalacturonan)
branching from a backbone of D-galacturonic acid residues.[4][5]
Rhamnogalacturonan I pectins (RG-I) contain a backbone of
the repeating disaccharide:
4)-α-D-galacturonic acid-(1,2)-α-L-rhamnose-(1 .
From many of the rhamnose residues,
sidechains of various neutral sugars branch off.
The neutral sugars are mainly
D-galactose, L-arabinose and D-xylose,
the types and proportions of neutral sugars
varying with the origin of pectin.[4][5][6]
Another structural type of pectin is
rhamnogalacturonan II (RG-II),
which is a less frequent complex,
highly branched polysaccharide.[7] Rhamnogalacturonan II
is classified by some authors within the group of
substituted galacturonans since the rhamnogalacturonan II backbone
is made exclusively of D-galacturonic acid units.[5]
. guar gum is a water-soluble fiber:
a polysaccharide composed of
the sugars galactose and mannose.
The backbone is a linear chain of
β 1,4-linked mannose residues
to which galactose residues are 1,6-linked
at every second mannose, forming short side-branches.
Unlike locust bean gum, it is not self-gelling;
However, either borax or calcium
can cross-link guar gum, causing it to gel.
. economical because it has almost 8 times
the water-thickening potency of cornstarch .
. konjac plant contains around 40% glucomannan gum.
(a dietary fiber made of polysaccharides:
The component sugars are β-(1→4)-linked D-mannose
and D-glucose in a ratio of 1.6:1.
The degree of branching is about 8%
through β-(1→6)-glucosyl linkages).
All carrageenans are
high-molecular-weight polysaccharides
made up of repeating galactose units
and 3,6 anhydrogalactose (3,6-AG),
both sulfated and nonsulfated.
. carrageenan and processed eucheuma seaweed
may be a source of degraded carrageenan (poligeenan)
which may cause ulcerations in the gastro-intestinal tract
and gastro-intestinal cancer.
. carrageenan induces inflammation in human
intestinal epithelial cells in tissue culture
through a BCL10-mediated pathway that leads to
activation of NFkappaB and IL-8.
Carrageenan may be immunogenic due to its
unusual alpha-1,3-galactosidic link
that is part of its disaccharide unit structure.
Consumption of carrageenan may have a role in
intestinal inflammation and possibly
inflammatory bowel disease, since BCL10 resembles NOD2,
mutations of which are associated with
genetic proclivity to Crohn's Disease.
Carrageenan is reported to interfere with macrophage activity .
agar-agar is a polymer of galactose:
(lactose is glucose*Galactose;
Lactose is found primarily in milk and milk products.
. the Leloir Pathway converts galactose
into glucose quickly because,
glucose is less susceptible than galactose
to the formation of nonspecific glycoconjugates,
molecules with at least one sugar
attached to a protein or lipid.
U.S. Food and Drug Administration (FDA),
with support from the TSE Advisory Committee,
(Transmissible spongiform encephalopathy)
has since 1997 been monitoring the potential risk of
transmitting animal diseases,
especially bovine spongiform encephalopathy (BSE).
The FDA study concluded: "...steps such as
heat, alkaline treatment, and filtration
could be effective in reducing the level of
contaminating TSE agents;
however, scientific evidence is insufficient at this time
to demonstrate that these treatments
would effectively remove the BSE infectious agent
if present in the source material."
The Scientific Steering Committee (SSC) of the
European Union (EU) in 2003 stated that
the risk associated with bovine bone gelatin
is very low or zero.
No comments:
Post a Comment