Use of an esterase to enhance ethyl ester content in fermentation media
Methods to prepare vegetable oil compositions having an elevated ethyl ester content are provided.
1. A method for enhancing properties of vegetable oil obtained from ground vegetable material, comprising:
providing a first composition comprising water, ground vegetable material, and vegetable fat;
enzymatically saccharifying a portion of the ground vegetable material to sugar;
fermenting the sugar to form a second composition comprising ethanol, water, ground vegetable material and vegetable fat; and
isolating vegetable oil from the second composition,
wherein an exogenous esterase is combined with the first composition and/or the second composition in an amount from 0.001 to 0.4% w/w of the weight of the vegetable fat, and wherein the isolated vegetable oil has a fatty acid ethyl ester content that is greater than 2% w/w of the total weight of the isolated vegetable oil.
2. The method of claim 1 , wherein the fatty acid ethyl ester content is greater than 5% w/w of the total weight of the isolated vegetable oil.
3. The method of claim 1 , wherein the fatty acid ethyl ester content is greater than 10% w/w of the total weight of the isolated vegetable oil.
4. The method of claim 1 , wherein the fatty acid ethyl ester content is greater than 30% w/w of the total weight of the isolated vegetable oil.
5. The method of claim 1 , wherein the esterase is in an amount that is up to 0.01% w/w of the weight of the vegetable fat.
6. The method of claim 1 , wherein the esterase is in an amount that is up to 0.04% w/w of the weight of the vegetable fat.
7. The method of claim 1 , wherein the esterase is in an amount that is from 0.01% to 0.4% w/w of the weight of the vegetable fat.
8. The method of claim 1 , wherein the exogenous esterase is combined with both the first and second composition.
9. The method of claim 1 , wherein the first composition comprises 20 to 50% wt-% of the ground vegetable material.
10. A method to decrease free fatty acids in vegetable oil obtained from ground vegetable material, comprising:
providing a first composition comprising water, ground vegetable material, and vegetable fat;
enzymatically saccharifying a portion of the ground vegetable material to sugar;
fermenting the sugar to form a second composition comprising ethanol, water, ground vegetable material and vegetable fat; and
isolating vegetable oil from the second composition,
wherein an exogenous esterase is combined with the first composition and/or the second composition in an amount from 0.001 to 0.4% w/w of the weight of the vegetable fat, and wherein the isolated vegetable oil has a decreased free fatty acid content relative to a corresponding composition obtained from the same method and under the same conditions and with the same materials except that lacks the exogenous esterase.
11. The method of claim 10 , wherein the fatty acid ethyl ester content is greater than 2% w/w of the total weight of the isolated vegetable oil.
12. The method of claim 10 , wherein the fatty acid ethyl ester content is greater than 7% w/w of the total weight of the isolated vegetable oil.
13. The method of claim 10 , wherein the esterase is in an amount that is up to 0.01% w/w of the weight of the vegetable fat.
14. The method of claim 10 , wherein the esterase is in an amount that is from 0.01% to 0.4% w/w of the weight of the vegetable fat.
15. A method to alter the viscosity of vegetable oil obtained from ground vegetable material, comprising:
providing a first composition comprising water, ground vegetable material, and vegetable fat;
enzymatically saccharifying a portion of the ground vegetable material to sugar;
fermenting the sugar to form a second composition comprising ethanol, water, ground vegetable material and vegetable fat; and
isolating vegetable oil from the second composition,
wherein an exogenous esterase is combined with the first composition and/or the second composition in an amount from 0.001 to 0.4% w/w of the weight of the vegetable fat, and wherein the isolated vegetable oil has an altered viscosity relative to a corresponding composition obtained from the same method and under the same conditions and with the same materials except that lacks the exogenous esterase.
16. The method of claim 15 , wherein more than 50% of the ground vegetable material is capable of passing through a 0.5 mm screen.
17. The method of claim 15 , wherein the pH is maintained in the range of 3 to 6 during the fermenting step.
18. The method of claim 15 , wherein the pH is maintained in the range of 3 to 6 and the temperature is maintained in the range of 25° C. to 40° C. during the fermenting step.