The present invention is related to a method for increasing the trans-specificity of a beta-carotene oxidase (BCO), particularly insect BCO, to be used in the production of vitamin A aldehyde (retinal) from conversion of beta-carotene, with at least about 75 to 100% of retinal in the trans-isoform.

The present invention relates to a composition for preparing retinoid, and more specifically, the composition comprises: a NADH or NADPH, a Beta-Carotene Oxygenase and a flavodoxin or a ferredoxin or a reductase of flavodoxin or ferredoxin; or a microorganism expressing them; or a culture or pulverized product of the microorganism, and thus can expand the supply metabolism of reducing electrons to enhance retinoid productivity through an increase in the activity of the cytochrome P450 system and provide a foundation for the low-cost production of raw materials, and thereby enhance the economic feasibility and efficiency of retinoid production.