Process for the generation of acetaldehyde from ethanol
AssigneeThe Coca-Cola Company
InventorWynn R. Raymond
Life of this patent
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Abstract
Disclosed herein is a process for the enzyme-catalyzed conversion of ethanol to acetaldehyde utilizing tris (hydroxy-methyl) aminomethane as a buffering and complexing agent. The process is particularly useful for bringing about the in situ oxidation of ethanol, contained in a fruit essence, to acetaldehyde.
Claims29
In a process for the enzyme-catalyzed conversion of ethanol to acetaldehyde wherein ethanol is reacted in the presence of alcohol dehydrogenase and nicotinamide adenine dinucleotide to form acetaldehyde, the improvement comprising conducting said reaction in the presence of tris (hydroxymethyl) aminomethane at conditions at which acetaldehyde formed in the reaction forms an associated complex with said tris (hydroxymethyl) aminomethane, and recovering acetaldehyde from said associated complex.
A process for the liquid-phase, enzyme-catalyzed conversion of ethanol to acetaldehyde, comprising:
- (a) reacting ethanol in the presence of alcohol dehydrogenase, nicotinamide adenine dinucleotide and tris (hydroxymethyl) aminomethane to form as reaction products acetaldehyde in the form of an associated complex with said tris (hydroxymethyl) aminomethane and reduced nicotinamide adenine dinucleotide;
- and
- (b) oxidizing said reduced nicotinamide adenine dinucleotide to provide additional nicotinamide adenine dinucleotide for reaction with said ethanol.
A process for the liquid-phase, enzyme-catalyzed conversion of ethanol to acetaldehyde, comprising:
- (a) providing a first zone comprised of ethanol, alcohol dehydrogenase, nicotinamide adenine dinucleotide and tris (hydroxymethyl) aminomethane;
- (b) providing a second zone comprised of ethanol, nicotinamide adenine dinucleotide and tris (hydroxymethyl) aminomethane, alcohol dehydrogenase being absent in said second zone;
- said first and second zones being separated by a semi-permeable membrane sized so as to retain said alcohol dehydrogenase in said first zone and to permit free permeation between said first and second zone of all other starting materials and reaction products formed therefrom;
- (c) bringing about the reaction of ethanol to acetaldehyde in the presence of said alcohol dehydrogenase, nicotinamide adenine dinucleotide and tris (hydroxymethyl) aminomethane in said first zone;
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- (d) recovering from said second zone the associated complex of acetaldehyde and tris (hydroxymethyl) aminomethane formed in the reaction in said first zone and which has permeated across said semi-permeable membrane into said second zone.
A process for the continuous, liquid-phase, enzyme-catalyzed conversion of ethanol to acetaldehyde, comprising:
- (a) providing a first, continuous flowing recirculating stream comprised of ethanol, alcohol dehydrogenase, nicotinamide adenine dinucleotide, flavin mononucleotide and tris (hydroxymethyl) aminomethane;
- (b) providing a second, continuous flowing stream comprised of ethanol, nicotinamide adenine dinucleotide, flavin mononucleotide and tris (hydroxymethyl) aminomethane, said second stream being free of alcohol dehydrogenase, said first and second streams being separated by a semi-permeable membrane sized so as to retain alcohol dehydrogenase in said first stream yet permit free permeation between said first and second streams of all other materials therein, including reaction products thereof;
- (c) continuously flowing said streams in a manner which brings about contact of all materials contained therein by means of permeation across said semi-permeable membrane at conditions at which ethanol is converted to acetaldehyde and said acetaldehyde forms an associated complex with said tris (hydroxymethyl) aminomethane;
- (d) thereafter subjecting the continuously flowing second stream to illumination to convert reduced nicotinamide adenine dinucleotide present therein to nicotinamide adenine dinucleotide;
- (e) thereafter adding oxygen to the continuously flowing second stream at conditions wherein flavin mononucleotide reduced in the conversion in step (d) is regenerated;
- (f) thereafter subjecting the continuously flowing second stream to conditions wherein hydrogen peroxide produced in the regeneration in step (e) is converted to oxygen and water;
- (g) thereafter recirculating said second stream to provide contact therewith, across the semi-permeable membrane, with said first stream to bring about further reaction of ethanol to acetaldehyde,
- said associated complex of acetaldehyde and tris (hydroxymethyl) aminomethane being at least periodically removed from said second stream;
- and the materials of said first and second streams being at least periodically replenished as required to bring about the desired reactions and produce concentration gradients sufficient to cause the permeation of materials to and from the respective streams across the semi-permeable membrane.
In a process for converting ethanol to acetaldehyde in the presence of alcohol dehydrogenase and a co-factor therefor, the improvement comprising conducting said conversion in a first reaction zone containing tris(hydroxymethyl)aminomethane and in which ethanol is in contact with said alcohol dehydrogenase and its co-factor and providing a second zone containing tris(hydroxymethyl)aminomethane, ethanol and cofactor, which is separated from said first reaction zone by a semi-permeable membrane sized so as to prevent passage of alcohol dehydrogenase, but allow passage of its co-factor, ethanol, tris(hydroxymethyl)aminomethane and reaction products.
Dependencies are inferred from the claim text.