TABLE 2.

Characteristics of the 34 peptides contained in the tryptic/chymotryptic hydrolysate of β-casein^a

Measured mass (Da; mean ± SD)	Sequence assignment (β-casein amino acids)	Peak no.
373.40b	26–28	2
388.40b	30–32	3
389.30b	94–97	1
407.20	191–193	12
512.30b	49–52	13
516.50b	29–32	4
532.40b	140–143	10
645.50b	100–105	5
646.40	53–58	6
648.50b	164–169	4
688.70b	134–139	21
741.50b	203–209	22
747.50b	108–113	14
750.50b	114–119	16
779.60b	170–176	10
820.40b	184–190	18
829.70b	177–183	8
872.80	98–105	7
903.50b	126–133	15
933.80b	184–191	22
1,012.94b	106–113	11
1,270.49 ± 0.99	192–202	16
1,383.14 ± 0.07	191–202	19
1,396.19 ± 0.56	114–125	17
1,565.69 ± 0.15	59–72	20
1,574.99 ± 0.29	126–139	23
2,062.00b	33–48	9
2,089.60b	126–143	25
2,150.80b	145–163	22
2,281.18 ± 0.98	144–163	22
2,556.98 ± 0.28	33–52	17
2,742.18 ± 0.29	69–93	24
3,123.23 ± 0.07	1–25	18
3,864.78 ± 0.56	59–93	25

^aThe mass of each peptide was determined by RP-HPLC–ESI-MS. Sequence assignment was done from the masses, and the sequences were all verified by MS-MS. The peak numbers correspond to those indicated in the RP-HPLC profile of the β-casein peptides in Fig. 5. 

^bSingly charged molecular ions (no SD).