2008 Volume 55 Issue 2 Pages 89-93
The characteristic effect of such amino acid couples as aspartic acid (Asp) and glutamic acid (Glu), Glu and lysine (Lys), and asparagine (Asn) and glutamine (Gln) selected by the difference in net charge on the gelatinization temperature (GT) and viscosity of potato starch granules was analyzed from the results evaluated by differential scanning calorimeter and rapid viscoanalyzer, respectively. These results were compared with those of the individual amino acids. Asp, Glu and Lys had a greater effect than Asn and Gln on increasing GT, and markedly reduced the peak viscosity (PV). The effect of the Asp+Glu couple, which both have a negative net charge, on GT was according to the sum of the increasing effect of the individual amino acids on GT, and that of the Glu+Lys couple, which respectively have a negative and positive net charge, was synergistically multiplied by those of the two. However, the effect of the Asn+Gln couple, which both have a zero net charge, on GT was hard to estimate due to little change in GT. The effect of the Asp+Glu, and Glu+Lys couples on PV both approached the sum of the decreasing effect of the respective two.