Reduced coenzyme Q10-containing composition comprising a surfactant which is stable against oxidation and method for stabilization by mixing with surfactant(s)

A method for stabilization of reduced coenzyme Q10 against oxidation, comprising providing a reduced coenzyme Q10-containing composition containing reduced coenzyme Q10 and a propylene glycol fatty acid ester, wherein the retention rate of reduced coenzyme Q10 after being preserved in air at 40° C. for 2 weeks is not less than 80 wt %, by mixing a propylene glycol fatty acid ester with reduced coenzyme Q10 to prepare a composition which protects reduced coenzyme Q10 from oxidation,

• wherein a fatty acid residue of the propylene glycol fatty acid ester is one or more fatty acid residues selected from the group consisting of caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid and linolenic acid, and
• wherein the amount of propylene glycol fatty acid ester in the composition is not less than 20 wt % and the amount of reduced coenzyme Q10 in the composition is not more than 40 wt %.