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Halloj!
Hittade en gammal burk med Kreatin Puryvate i kapselform som blivit bortglömd långt in i träningshyllan.
Grejen är den att bäst före datumet var Januari 2014 och eftersom det är 70+ kapslar kvar så vill jag ju ta denna nu när min nuvarande snart är slut.
Det jag undrar är om det är ”ätbart” fortfarande eller om det kanske förlorat sin effekt, vad tror ni?/Samuel
Enligt en tillverkare av kreatin:
”To the best of our knowledge creatine is not degraded at room temperature
at all. Creatinine is only formed in water. This reaction is a elimination
of water (not an oxidation) and is the only reaction of creatine in water
at room temperature. The reaction is reversible and the equilibrium depends
on the pH of the solution.Please refer also to the following literature:
The changes of creatine and creatinine. Hahn, Amandus; Barkan, Georg.
Z. Biol. (1920), 72 25-36. Journal written in Unavailable. CAN
15:4740 AN 1921:4740 CAPLUSAbstract
The authors studied the reciprocal changes of creatine and creatinine in
alk. and acid solns. The creatine used was prepd. by sepn. from muscle
ext. The creatinine was purchased. All detns. were made colorimetrically
and creatinine solns. were used as standards. The expts. showed that the
reaction of the change from creatine to creatinine and vice versa is an
incomplete reaction of the first order and has a well defined point of
equilibrium. In acid soln. creatine goes completely over into creatinine
with the formation of a soln. of creatinine cations.Creatine-creatinine equilibrium. The apparent dissociation constants of
creatine and creatinine. Cannan, Robert Keith; Shore, Agnes. Dept.
Biochemistry, University College, London, Biochem. J. (1928), 22
920-9. Journal written in Unavailable. CAN 23:932 AN 1929:932
CAPLUSAbstract
Detns. of the apparent dissocn. const. of creatinine at 15°, 25° and 30°
and of the first dissocn. const. of creatine at 17°, 25° and 30°, have been
made. The velocity consts. of the reversible system creatinine-creatinine
have been detd. at 30° over the pH range 2 to 10, and have been related to
[H+], the dissocn. consts. of the reactants and certain empirical consts.Equilibrium between creatine and creatinine in aqueous solution. The effect
of hydrogen ion. Edgar, Graham; Shiver, H. E. J. Am. Chem. Soc.
(1925), 47 1179-88. Journal written in Unavailable. CAN 19:11791
AN 1925:11791 CAPLUSAbstract
The reversible reaction creatine .dblharw. creatinine proceeds definitely
to a condition of equil. in aq. solns. and is markedly influenced by temp.;
the proportion of creatinine increases with increasing temp. The equil.
const. can be calcd. from the equation log K = -1084/T + 3.3652; the
observed values are: 25°, 0.540; 50°, 1.022; 75°, 1.593; 100°, 2.890° and
agree well with the calcd. values. The effect of changing the H-ion concn.
is very marked, the equil. shifting towards the creatinine side with
decreasing pH; the nature of the buffer soln. is unimportant; the effect is
particularly marked between pH 1.5 and 3.0; the rate at which equil. is
reached.”Kort version: Läs första meningen
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