Thermal Degradation of Vitamin B1

1
Thermal Degradation of Vitamin B1
H2N
N
-
Cl
H2C

N
N
HO
S
Thiazol
Pyrimidine
2
Degradation of Thiamine under Basic Condition
H2N
H2N
N
- OH-
N
N
-
Cl

H2C
CH3

N
H2O
HO
N
S
N
HO
S

no odor
( Coffee aroma with meaty note )
3
Degradation of Thiamine under Acidic Condition
H2N

N
H2N
H
H2C
N
N
H3C
H3C
N

H

C
H
H2C
H
N
N



S
HO
HO
S
CHO
H2N
O
N

HCOOH
HO
CH3
C
CH
(CH2)2
H2N
S
H
N
Coffee
No odor
4
Formation of Thiazole Compounds from Thiamine
N
N
N
-H2O
Reduction
HO
(Cocoa, beef)
S
S
S
Cocoa
Methyl-vinyl-thiazole
Methyl, ethyl-thiazole
5
Formation of Furan Compounds from Thiamine
O
Cyclization
O
-SH
H3C-C-CH2-CH2-CH2-OH
H3C-C-CH-CH2-CH2-OH

H
SH
From the decomposition of thiamin under acidic
condition
Reduction
-H2O
C
OH
CH3
CH3
-H2
O
O
O
CH3
( Coffee, tea )
6
Formation of Furan Compounds from Thiamine
O
OH
O
-H2S
keto enolization
H3C-C-CH-CH2-CH2-OH
H3C-CC-CH2-CH2-OH
H3C-C-CH-CH2-CH2-OH
H2O
OH
OH
SH
OH
H3C-CH-C-CH2-CH2-OH
O
O
-H2O
Roasted onion, beef, tomato, white bread
CH3
O