Enzymatic Improvement of Food Flavor

II. Removal of Beany Flavor from Soybean Products by Aldehyde Dehydrogenase

Abstract

Aldehyde dehydrogenase catalyzes the irreversible conversion of aldehydes into their corresponding acids. NAD-dependent aldehyde dehydrogenase purified from bovine liver mitochondria was used to remove the green beany flavor of soybean products. Incubation of the enzyme, in the presence of NAD⁺, with defatted soybean extracts or with soybean milk, resulted in the almost complete disappearance or in a great reduction of the flavor. It was found from experiments with pyrazole, an inhibitor of alcohol dehydrogenase, was used, that alcohols contributing to the beany flavor were converted into acids by the cooperative action of alcohol dehydrogenase and aldehyde dehydrogenase. The protein isolate prepared from the soybean extract after treatment with these enzymes produced no substantial beany flavor after storage in powdered form. Aldehyde dehydrogenase improved flavor in extract of mutton.