Characterization and application of porcine liver aldehyde oxidase in the off-flavor reduction of soy proteins Academic Article uri icon

abstract

  • Two enzyme forms of porcine liver aldehyde oxidase (PAO-I and PAO-II) (aldehyde:oxygen oxidoreductase, EC 1.2.3.1) were purified to homogeneity by using affinity chromatography. Both enzyme forms, PAO-I and PAO-II, have similar pI values of 5.8 and molecular masses of 262 000 and 25 000 Da, respectively. Compared with PAO-II, PAO-I showed greater affinity for the soy off-flavor-causing aldehydes n-pentanal and n-hexanal. Purified PAO-I was stable between pH 7.1 and 10.7 and at temperatures up to 45C. Energy of denaturation for PAO-I (158.1 kJ/molK-1) was more than 3-fold higher than the energy of activation (47 kJ/molK-1). Gas chromatography analysis showed that more headspace volatiles were present in the water extract of soy proteins at pH 7.0 than at pH 9.0. The incubation of a soy protein extract and PAO-I reduced the pentanal and hexanal contents by as much as 90%. The sensory panelists perceived lower beany flavor (p < 0.01) of the enzyme-treated soy protein extract than the control.

published proceedings

  • JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

altmetric score

  • 3

author list (cited authors)

  • Maheshwari, P., Murphy, P. A., & Nikolov, Z. L.

citation count

  • 14

complete list of authors

  • Maheshwari, P||Murphy, PA||Nikolov, ZL

publication date

  • January 1997