Effects of amino acids on the physiochemical properties of potato starch

• Charged amino acids decreased swelling power and solubility of potato starch.
• They decreased L∗ value and gel strength of starch gels.
• They increased starch syneresis with freeze–thaw treatment.
• They reduced the peak G′ of starch paste during heating.
• Neutral amino acids caused no change of those properties of potato starch.

The objective of this study was to evaluate effects of different amino acid additives (phenylalanine (Phe), methionine (Met), lysine (Lys), arginine (Arg), aspartic acid (Asp) and glutamic acid (Glu)) on the physicochemical properties of potato starch gels. Charge-carrying amino acids (Lys, Arg, Asp and Glu) significantly decreased the swelling power, solubility, light transmittance, L∗ value and gel strength of potato starch, but increased syneresis during freeze–thaw treatment, while neutral amino acids (Phe and Met) did not cause modifications in starch gels. During heating, potato starch with fortified charge-carrying amino acids showed a lower peak G′ (storage modulus), when compared with Phe and Met. Results showed that charge-carrying amino acids could modify physicochemical properties and improve the nutritional values of starch-based products.