Microbial transglutaminase crosslinks β-casein and β-lactoglobulin to heterologous oligomers under high pressure

SummaryHydrolysis of β-lactoglobulin B (β-lg B) by pepsin, a process slow at ambient conditions, is facilitated at a moderately high hydrostatic pressure such as 300 MPa, corresponding to an apparent volume of activation ΔV# = −63 ml mol−1 at pH 2·5, 30 °C and Γ/2=0·16. Digestion of β-lg by trypsin and thermolysin is likewise enhanced by pressure, and the pressure effect has been traced to pressure denaturation of β-lg B, which by high-pressure fluorescence spectroscopy has been shown to have a large negative volume of reaction, ΔV° = −98 ml mol−1, at pH 6·7, 30 °C and Γ/2 = 0·16. Pressure denaturation is only slowly reversed following release of pressure and the enhanced digestibility is maintained at ambient pressure for several hours.

Download Full-text

Influence of Binding of Sodium Dodecyl Sulfate, All-trans-retinol, and 8-Anilino-1-naphthalenesulfonate on the High-Pressure-Induced Unfolding and Aggregation of β-Lactoglobulin B

Journal of Agricultural and Food Chemistry ◽

10.1021/jf050841v ◽

2005 ◽

Vol 53 (20) ◽

pp. 8010-8018 ◽

Cited By ~ 23

Author(s):

Thérèse Considine ◽

Harjinder Singh ◽

Hasmukh A. Patel ◽

Lawrence K. Creamer

Keyword(s):

High Pressure ◽

Sodium Dodecyl Sulfate ◽

Sodium Dodecyl ◽

Dodecyl Sulfate ◽

Β Lactoglobulin

Download Full-text

Effects of heat treatment and high pressure on the subsequent lactosylation of β-lactoglobulin

Food Chemistry ◽

10.1016/j.foodchem.2005.08.039 ◽

2006 ◽

Vol 99 (4) ◽

pp. 651-655 ◽

Cited By ~ 12

Author(s):

M RADAMENDOZA ◽

M VILLAMIEL ◽

E MOLINA ◽

A OLANO

Keyword(s):

Heat Treatment ◽

High Pressure ◽

Β Lactoglobulin

Download Full-text

Effect of high-pressure treatment at various temperatures on indigenous proteolytic enzymes and whey protein denaturation in bovine milk

Journal of Dairy Research ◽

10.1017/s002202990800321x ◽

2008 ◽

Vol 75 (3) ◽

pp. 262-269 ◽

Cited By ~ 15

Author(s):

Golfo Moatsou ◽

Constantinos Bakopanos ◽

Dimitis Katharios ◽

George Katsaros ◽

Ioannis Kandarakis ◽

...

Keyword(s):

High Pressure ◽

Whey Protein ◽

Cathepsin D ◽

Room Temperature ◽

Protein Denaturation ◽

Proteolytic Enzymes ◽

Bovine Milk ◽

Negative Effects ◽

Milk Serum ◽

Β Lactoglobulin

The objective of the present study was to determine the effect of high pressure (HP) processing (200, 450 and 650 MPa) at various temperatures (20, 40 and 55°C) on the total plasmin plus plasminogen-derived activity (PL), plasminogen activator(s) (PA) and cathepsin D activities and on denaturation of major whey proteins in bovine milk. Data indicated that transfer of both PL and PA from the casein micelles to milk serum occurred at all pressures utilized at room temperature (20°C). In addition to the transfer of PL and PA from micelles, there were reductions in activities of PL (16–18%) and PA (38–62%) for the pressures 450 and 650 MPa, at room temperature. There were synergistic negative effects between pressure and temperature on residual PL activity at 450 and 650 MPa and on residual PA activity only at 450 MPa. Cathepsin D activity in the acid whey from HP-treated milk was in general baroresistant at room temperature. The residual activity of cathepsin D decreased significantly at 650 MPa and 40°C and at the pressures 450 and 650 MPa at 55°C. Synergistic negative effects on the amount of native β-lactoglobulin were observed at 450 and 650 MPa and on the amount of native α-lactalbumin at 650 MPa. There were significant correlations between enzymatic activities (PL, PA and cathepsin D) and the residual native β-lactoglobulin and α-lactalbumin in bovine milk. In conclusion, HP significantly affected the activity of indigenous proteolytic enzymes and whey protein denaturation in bovine milk. Reduction in activity of indigenous enzymes (PL, PA and cathepsin D) and transfer of PL and PA from the casein to milk serum induced by HP is expected to have a profound effect on cheese yield, proteolysis during cheese ripening and quality of UHT milk during storage.

Download Full-text