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Table I.

Physicochemical characteristics of milk samples during dialysis against a weak cation exchanger. D2 and D3 are two repetitions of the dialysis experiment. tdialysis, time of dialysis; WP, whey proteins; tgel, gelation time; pHgel, gelation pH; tanδmin, minimum value of tanδ just after gelation; tanδ800, tanδ at 800 min; Δtan, difference between maximal and minimal value of tanδ; G′800, G′ at 800 min; tanδ800, tanδ at 800 min.

tdialysis (h) ζ-potential (mV)
Casein (g·kg−1) WP (g·kg−1) NPN (g·kg−1) tgel (min) pHgel tanδmin tanδ800 Δtan G′800 (Pa) tanδ800
NH* H*
D2 0 −20.4 ± 0.9aAχ −18.3 ± 0.3aBε 39.37 ± 1.04 8.55 ± 0.10 2.37 209.5 5.33 0.338 0.406 0.070 854 0.2161
14.5 −19.8 ± 0.8abA −17.1 ± 0.7bB 39.34 ± 0.01 8.30 ± 0.10 2.14 225.6 5.31 0.375 0.453 0.078 643 0.2447
22.08 −18.9 ± 0.8bdA −15.6 ± 0.6cB 34.64 ± 0.07 8.00 ± 0.03 2.00 226.1 5.40 0.393 0.467 0.074 619 0.2411
38.42 −16.8 ± 0.8ceA −15.3 ± 0.5cB 33.91 ± 0.24 8.53 ± 0.01 1.67 247.8 5.41 0.417 0.492 0.075 650 0.2516
43.08 −17.8 ± 0.7deA −15.9 ± 0.5cB 33.79 ± 0.24 8.81 ± 0.04 1.34 240.0 5.34 0.429 0.500 0.071 714 0.2462
D3 0 −18.5 ± 0.5aAφ −17.0 ± 0.8aBλ 36.12 ± 4.23 9.47 ± 0.02 2.23 215.7 5.34 0.336 0.406 0.070 839 0.2215
14.25 −18.7 ± 0.8aA −17.4 ± 1.1aA 35.10 ± 0.10 8.93 ± 0.03 1.90 228.7 5.57 0.384 0.453 0.069 764 0.2453
21.75 −18.5 ± 0.7aA −16.2 ± 0.7aB 34.82 ± 3.89 8.86 ± 0.01 1.80 237.5 5.16 0.398 0.470 0.073 651 0.2421
38.26 −17.5 ± 0.8bA −14.4 ± 0.9bB 33.70 ± 4.08 8.59 ± 0.01 1.57 358.1 5.10 0.447 0.513 0.066 702 0.2735
*

NH, non heat-treated; H, heat-treated.

abcde

Mean of sample in a column obtained by one dialysis experiment (D2 or D3) with different superscripts differ significantly (P < 0.05%).

AB

Mean of samples on the same row with different superscripts differ significantly (P < 0.05%).

χεφλ

Mean of samples at zero time dialysis with different superscripts differ significantly (P < 0.05%).