Abstract: Provided are: a composition containing 96-99 area % of eicosapentaenoic acid alkyl ester, the composition having an arachidonic acid alkyl ester content of 0.7 area % or less, and an eicosapentaenoic-acid-alkyl-ester mono-trans isomer content of 2.5 area % or less; and a method for producing a composition containing a high concentration of eicosapentaenoic acid alkyl ester, the method including performing precision distillation on a composition containing eicosapentaenoic acid alkyl ester, obtained by alkyl esterification of a raw material oil containing eicosapentaenoic acid, under a vacuum of 0.2 Torr or lower and a temperature of 190° C. or lower in the entire column, and performing a concentration treatment on the precision-distilled composition using chromatography.

Abstract: Provided are: a composition containing 96-99 area % of eicosapentaenoic acid alkyl ester, the composition having an arachidonic acid alkyl ester content of 0.7 area % or less, and an eicosapentaenoic-acid-alkyl-ester mono-trans isomer content of 2.5 area % or less; and a method for producing a composition containing a high concentration of eicosapentaenoic acid alkyl ester, the method including performing precision distillation on a composition containing eicosapentaenoic acid alkyl ester, obtained by alkyl esterification of a raw material oil containing eicosapentaenoic acid, under a vacuum of 0.2 Torr or lower and a temperature of 190° C. or lower in the entire column, and performing a concentration treatment on the precision-distilled composition using chromatography.

Abstract: Provided are: a composition containing 96-99 area % of eicosapentaenoic acid alkyl ester, the composition having an arachidonic acid alkyl ester content of 0.7 area % or less, and an eicosapentaenoic-acid-alkyl-ester mono-trans isomer content of 2.5 area % or less; and a method for producing a composition containing a high concentration of eicosapentaenoic acid alkyl ester, the method including performing precision distillation on a composition containing eicosapentaenoic acid alkyl ester, obtained by alkyl esterification of a raw material oil containing eicosapentaenoic acid, under a vacuum of 0.2 Torr or lower and a temperature of 190° C. or lower in the entire column, and performing a concentration treatment on the precision-distilled composition using chromatography.

Abstract: A microbial oil comprising dihomo-?-linolenic acid as a constituent fatty acid of an oil, the microbial oil has a content, in terms of a weight ratio of arachidonic acid relative to dihomo-?-linolenic acid (arachidonic acid/dihomo-?-linolenic acid) of less than 1/13. Preferably, the microbial oil has a triglyceride content of greater than or equal to 70% by weight, and a saturated fatty acid content of less than or equal to 40% by weight. Moreover, a lower alcohol ester of dihomo-?-linolenic acid or a free fatty acid of dihomo-?-linolenic acid obtained from the microbial oil is provided.

Abstract: Provided are: a composition containing 96-99 area % of eicosapentaenoic acid alkyl ester, the composition having an arachidonic acid alkyl ester content of 0.7 area % or less, and an eicosapentaenoic-acid-alkyl-ester mono-trans isomer content of 2.5 area % or less; and a method for producing a composition containing a high concentration of eicosapentaenoic acid alkyl ester, the method including performing precision distillation on a composition containing eicosapentaenoic acid alkyl ester, obtained by alkyl esterification of a raw material oil containing eicosapentaenoic acid, under a vacuum of 0.2 Torr or lower and a temperature of 190° C. or lower in the entire column, and performing a concentration treatment on the precision-distilled composition using chromatography.

Abstract: A method for producing monovalent unsaturated free fatty acids having 20 and/or 22 carbons or low-grade alcohol esters thereof, said method involving the following: obtaining free fatty acids or low-grade alcohol esters through the hydrolysis or alcoholysis of oils and fats derived from marine products; carrying out distillation on the free fatty acids or low-grade alcohol esters, and reducing the concentration of fatty acids with 18 or less carbons in the low-grade alcohol esters or free fatty acids; and collecting fractions of monovalent unsaturated free fatty acids having 20 and/or 22 carbons or low-grade alcohol esters thereof by column chromatography based on reversed-phase distribution.

Abstract: Provided are: a composition containing 96-99 area % of eicosapentaenoic acid alkyl ester, the composition having an arachidonic acid alkyl ester content of 0.7 area % or less, and an eicosapentaenoic-acid-alkyl-ester mono-trans isomer content of 2.5 area % or less; and a method for producing a composition containing a high concentration of eicosapentaenoic acid alkyl ester, the method including performing precision distillation on a composition containing eicosapentaenoic acid alkyl ester, obtained by alkyl esterification of a raw material oil containing eicosapentaenoic acid, under a vacuum of 0.2 Torr or lower and a temperature of 190° C. or lower in the entire column, and performing a concentration treatment on the precision-distilled composition using chromatography.

Abstract: Provided are: a composition containing 96-99 area % of eicosapentaenoic acid alkyl ester, the composition having an arachidonic acid alkyl ester content of 0.7 area % or less, and an eicosapentaenoic-acid-alkyl-ester mono-trans isomer content of 2.5 area % or less; and a method for producing a composition containing a high concentration of eicosapentaenoic acid alkyl ester, the method including performing precision distillation on a composition containing eicosapentaenoic acid alkyl ester, obtained by alkyl esterification of a raw material oil containing eicosapentaenoic acid, under a vacuum of 0.2 Torr or lower and a temperature of 190° C. or lower in the entire column, and performing a concentration treatment on the precision-distilled composition using chromatography.

Abstract: Provided are: a composition containing 96-99 area % of eicosapentaenoic acid alkyl ester, the composition having an arachidonic acid alkyl ester content of 0.7 area % or less, and an eicosapentaenoic-acid-alkyl-ester mono-trans isomer content of 2.5 area % or less; and a method for producing a composition containing a high concentration of eicosapentaenoic acid alkyl ester, the method including performing precision distillation on a composition containing eicosapentaenoic acid alkyl ester, obtained by alkyl esterification of a raw material oil containing eicosapentaenoic acid, under a vacuum of 0.2 Ton or lower and a temperature of 190° C. or lower in the entire column, and performing a concentration treatment on the precision-distilled composition using chromatography.

Abstract: Provided are: a composition containing 96-99 area % of eicosapentaenoic acid alkyl ester, the composition having an arachidonic acid alkyl ester content of 0.7 area % or less, and an eicosapentaenoic-acid-alkyl-ester mono-trans isomer content of 2.5 area % or less; and a method for producing a composition containing a high concentration of eicosapentaenoic acid alkyl ester, the method including performing precision distillation on a composition containing eicosapentaenoic acid alkyl ester, obtained by alkyl esterification of a raw material oil containing eicosapentaenoic acid, under a vacuum of 0.2 Ton or lower and a temperature of 190° C. or lower in the entire column, and performing a concentration treatment on the precision-distilled composition using chromatography.

Abstract: Provided are: an eicosapentaenoic acid alkyl ester-ontaining composition which comprises 96-99 area % of an eicosapentaenoic acid alkyl ester, wherein the content of an arachidonic acid alkyl ester is 0.7 area % or less, and the content of mono-trans forms of the eicosapentaenoic acid alkyl ester is 2.5 area % or less; a method for producing a high-concentration eicosapentaenoic acid alkyl ester-containing composition, which comprises performing rectification on an eicosapentaenoic acid alkyl ester-containing composition with the degree of vacuum being 0.2 Torr or less and at a whole-column temperature 190° C. or less, and performing a concentration treatment on the rectified composition using chromatography, the eicosapentaenoic acid alkyl ester-containing composition being obtained by alkyl esterifying a feed oil containing eicosapentaenoic acid.

Abstract: A microbial oil comprising dihomo-?-linolenic acid as a constituent fatty acid of an oil, the microbial oil has a content, in terms of a weight ratio of arachidonic acid relative to dihomo-?-linolenic acid (arachidonic acid/dihomo-?-linolenic acid) of less than 1/13. Preferably, the microbial oil has a triglyceride content of greater than or equal to 70% by weight, and a saturated fatty acid content of less than or equal to 40% by weight. Moreover, a lower alcohol ester of dihomo-?-linolenic acid or a free fatty acid of dihomo-?-linolenic acid obtained from the microbial oil is provided.

Abstract: A microbial oil comprising dihomo-?-linolenic acid as a constituent fatty acid of an oil, the microbial oil has a content, in terms of a weight ratio of arachidonic acid relative to dihomo-?-linolenic acid (arachidonic acid/dihomo-?-linolenic acid) of less than 1/13. Preferably, the microbial oil has a triglyceride content of greater than or equal to 70% by weight, and a saturated fatty acid content of less than or equal to 40% by weight. Moreover, a lower alcohol ester of dihomo-?-linolenic acid or a free fatty acid of dihomo-?-linolenic acid obtained from the microbial oil is provided.

Abstract: Provided are: an eicosapentaenoic acid alkyl ester-containing composition which comprises 96-99 area % of an eicosapentaenoic acid alkyl ester, wherein the content of an arachidonic acid alkyl ester is 0.7 area % or less, and the content of mono-trans forms of the eicosapentaenoic acid alkyl ester is 2.5 area % or less; a method for producing a high-concentration eicosapentaenoic acid alkyl ester-containing composition, which comprises performing rectification on an eicosapentaenoic acid alkyl ester-containing composition with the degree of vacuum being 0.2 Torr or less and at a whole-column temperature 190° C. or less, and performing a concentration treatment on the rectified composition using chromatography, the eicosapentaenoic acid alkyl ester-containing composition being obtained by alkyl esterifying a feed oil containing eicosapentaenoic acid.

Abstract: A method for producing monovalent unsaturated free fatty acids having 20 and/or 22 carbons or low-grade alcohol esters thereof, said method involving the following: obtaining free fatty acids or low-grade alcohol esters through the hydrolysis or alcoholysis of oils and fats derived from marine products; carrying out distillation on the free fatty acids or low-grade alcohol esters, and reducing the concentration of fatty acids with 18 or less carbons in the low-grade alcohol esters or free fatty acids; and collecting fractions of monovalent unsaturated free fatty acids having 20 and/or 22 carbons or low-grade alcohol esters thereof by column chromatography based on reversed-phase distribution.

Abstract: A microbial oil comprising dihomo-?-linolenic acid as a constituent fatty acid of an oil, the microbial oil has a content, in terms of a weight ratio of arachidonic acid relative to dihomo-?-linolenic acid (arachidonic acid/dihomo-?-linolenic acid) of less than 1/13. Preferably, the microbial oil has a triglyceride content of greater than or equal to 70% by weight, and a saturated fatty acid content of less than or equal to 40% by weight. Moreover, a lower alcohol ester of dihomo-?-linolenic acid or a free fatty acid of dihomo-?-linolenic acid obtained from the microbial oil is provided.