Stability of Casein Micelles Cross-Linked by Transglutaminase

Sodium dodecyl sulfate-PAGE electrophoretograph of reconstituted low heat skim milk powder after incubation with 0.10g/L of transglutaminase for 0 (lane 1), 1 (lane 2), 2 (lane 3), 3 (lane 4), 4 (lane 5), 5 (lane 6), 6 (lane 7), 7 (lane 8), 8 (lane 9), or 24 (lane 10) h at 30°C.

Influence of addition of trisodium citrate to a final concentration of 0 (●), 10 (○), 20 (▾), 30 (▿), 40 (■), or 50 (□) mmol/L on the normalized L*-value of milk incubated with 0.10g/L of transglutaminase at 30°C for 0 to 24h. Values are means of data from triplicate experiments on individual milk samples, with the standard deviation indicated by vertical error bars.

Influence of addition of urea to a final concentration of 0 (●), 2 (○), 3 (▾), 4 (▿), or 6 (■) mol/L on the normalized L*-value of milk incubated with 0.10g/L of transglutaminase at 30°C for 0 to 24h. Values are means of data from triplicate experiments on individual milk samples, with the standard deviation indicated by vertical error bars.

Influence of addition of SDS to a final concentration of 0.00 (●), 0.25 (○), 0.50 (▾), 1.00 (▿), 1.50 (■), or 2.00 (□) % (wt/vol) on the normalized L*-value of milk incubated with 0.10g/L of transglutaminase at 30°C for 0 to 24h. Values are means of data from triplicate experiments on individual milk samples, with the standard deviation indicated by vertical error bars.

Influence of mixing milk, treated with 0.10g/L of transglutaminase for 0 to 24h at 30°C, with an equal volume of 70% (vol/vol) ethanol, followed by heating at 20 (●), 60 (○), 70 (▾), or 80 (▿)°C for 10min on its normalized L*-value. Values are means of data from triplicate experiments on individual milk samples with the standard deviation indicated by vertical error bars.

Influence of high pressure treatment at 0.1 (●), 300 (○), 400 (▾), 500 (▿), or 600 (■) MPa for 10min at 20°C on the normalized L*-value of milk treated with 0.10g/L of transglutaminase for 0 to 24h at 30°C. Values are means of data from triplicate experiments on individual milk samples with the standard deviation indicated by vertical error bars.

Influence of addition of 50mmol/L trisodium citrate (A), 6mol/L urea (B), or 20g/L SDS (C), heating to 80°C in the presence of 35% (vol/vol) ethanol (D), or high pressure treatment at 600MPa for 10min (E) on the normalized L*-value of skim milk treated with 0.1g/L of transglutaminase for 0 to 24h at 30°C. Data points represent experimentally determined values, whereas solids lines are best fits to the equation L_n^*(t) = a {1−b ● e^{(−c ● t)}}.