Free Access
Table I.
Mean data from physicochemical properties of milk throughout spring flush.
| Before turn out (n = 12) |
During turn out (n = 9) |
After turn out (n = 16) |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| Mean | SD | Range | Mean | SD | Range | Mean | SD | Range | |
| pH | 6.73 | 0.03 | 0.08 | 6.76 | 0.03 | 0.10 | 6.77 | 0.03 | 0.11 |
| Fat (%) | 4.50 | 0.63 | 1.87 | 3.98 | 0.46 | 1.26 | 4.29 | 0.56 | 2.07 |
| Protein (%) | 3.34 | 0.09 | 0.33 | 3.42 | 0.06 | 0.18 | 3.42 | 0.16 | 0.50 |
| Lactose (%) | 4.58 | 0.05 | 0.18 | 4.50 | 0.04 | 0.11 | 4.50 | 0.03 | 0.12 |
| TDC (mmol·L−1) | 35.4 | 1.4 | 4.0 | 34.0 | 1.5 | 4.0 | 33.4 | 1.1 | 4.0 |
| Ionic calcium (mmol·L−1) | 1.48 | 0.05 | 0.15 | 1.42 | 0.05 | 0.12 | 1.40 | 0.09 | 0.31 |
| Potassium (mmol·L−1) | 39.0 | 1.27 | 4.00 | 39.9 | 3.83 | 10.42 | 36.3 | 1.27 | 4.18 |
| Sodium (mmol·L−1) | 15.0 | 0.87 | 2.78 | 16.2 | 0.58 | 1.87 | 15.6 | 1.64 | 7.03 |
| TA (% lactic acid) | 0.14 | 0.01 | 0.03 | 0.14 | 0.01 | 0.03 | 0.14 | 0.01 | 0.04 |
| Ethanol stability (%) | 78 | 1.7 | 6 | 78 | 2.4 | 6 | 74 | 4.7 | 20 |
| Urea (mg·L−1) | 202 | 67 | 203 | 243 | 94 | 277 | 175 | 72 | 287 |
| Micelle diameter (nm) | 211 | 8.9 | 27 | 211 | 5.4 | 17 | 207 | 6.8 | 24 |
| Zeta potential (mV) | −28.3 | 1.2 | 4.4 | −27.8 | 0.9 | 2.5 | −26.9 | 0.9 | 3.0 |
| Sediment (%) | 0.77 | 0.66 | 2.43 | 0.51 | 0.13 | 0.38 | 0.41 | 0.15 | 0.43 |
| Heat coagulation (min) | 25 | 7.7 | 24 | 21 | 6.0 | 18 | 26 | 6.3 | 18 |
| RCTm (s) | 893 | 142 | 490 | 958 | 135 | 415 | 899 | 162 | 580 |
| RCTi (s) | 949 | 113 | 354 | 1126 | 213 | 708 | 989 | 185 | 586 |
| Acid gel strength (Force, N) | 1.99 | 0.13 | 0.42 | 2.06 | 0.10 | 0.32 | 2.09 | 0.18 | 0.71 |
| Stirred gel viscosity (G*, Pa) | 19.1 | 3.45 | 10.3 | 22.1 | 2.89 | 9.20 | 27.5 | 6.37 | 24.4 |
RCT, rennet clotting time; m, manually; i, instrumentally (C-VOR Rheometer).
Range is defined as the largest number minus the smallest number from the data set.