Dairy Chemistry And Biochemistry

HEAT-INDUCED CHANGES IN MILK 367

0 20 40 60 80 100 120 140

Time of heating (min)
Figure 9.17 Exposure of sulphydryl groups by heating milk at 75 (O), 80 (O), 85 (A) or 95
(A) "C; de-aerated milk heated at 85°C (a) (from Jenness and Patton, 1959).

Products

unknown y2

Histidine

Tryptophan

CH2 0 Lysinoalanine

CH3 0 [HI II I/

H~N-C-LLOH I 7 H2N-C-C-OH - y3

H I c=o

Alanine

/ 3 1 :\ k-H

Ornithine pyruvic acid

THz

CH2 0 I I/ HO

H

H2N-C-C-OH I 1. H2N- C I - C- OH H2N- C- I C-OH I/

I 7H2 I

S p2

p-aminoalnnine CH2 I 0

I //

I

H

H2N-C-C-OH

Lanthionine

NH

Figure 9.18 Interaction of dehydroalanine with amino acids.