Process for making flavor and fragrant compounds
The present invention relates to the production of aromatic hexanols and compositions containing them. In particular provided herein are methods of producing hexenols comprising: a) contacting a hydroperoxide of a polyunsaturated fatty acid with a modified hydroperoxide lyase to form a hexenal; and b) reducing the hexenal to a hexenol in the presence of a hydride donor, a ketoreductase, and a co-factor wherein the contacting and reducing steps are carried out at essentially the same time in the substantial absence of baker's yeast.
1. A composition comprising (Z)-3-hexenol produced by a method of producing an alcohol comprising:
a) contacting a 13-hydroperoxide of a polyunsaturated fatty acid selected from the group consisting of linoleic acid and alpha linolenic acid with a 13-hydroperoxide lyase to form a hexenal; and
b) reducing the hexenal in the presence of a hydride donor, a ketoreductase, and a co-factor;
wherein the contacting and reducing steps are carried out concomitantly;
wherein
the hydride donor is selected from the group consisting of a secondary alcohol, a primary alcohol, an alkandiol and a hydroxy acid or one of its esters;
the cofactor is selected from the group consisting of NADH and NADPH;
the hydroperoxide lyase is stable in the presence of the hydride donor, thus allowing for the concomitant hydroperoxide cleavage and hexanal reduction; and
the method does not require intact cells;
wherein the composition comprises (Z)-3-hexenol in an amount of greater than or equal to 12000 mg/L and less than or equal to 400 mg/L of the total amount of n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol, and wherein no n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol or n-hexanol have been removed after processing.
2. The composition as recited in claim 1 wherein the ratio of (Z)-3-hexenol to the total amount of n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol ranges, by weight, from 30:1 to 71:1.
3. The composition as recited in claim 1 comprising (Z)-3-hexenol wherein the composition comprises (Z)-3-hexenol in an amount of greater than or equal to 12000 mg/L and less than or equal to 400 mg/L of the total amount of n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol produced in the reaction, and wherein no n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, or n-hexanol have been removed after processing.