Vitamin A activity of acidulated soybean soapstocks in chicks

Acidulated soybean soapstock increased the vitamin A storage in the livers of young chicks receiving a practical‐type diet and improvet the survival of chicks reared on vitamin A‐deficient diets. The biological activity was mainly associated with one of the carotenoids present in the acidulated soapstock. This pigment is characterized by its red color on the MgO column, its position below lutein but slightly above cryptoxanthin on the same column, and its single absorption max at 460 mॖ in the visible region. Evidence is presented to show that the pigment is an artefact formed from lutein during the acidulation of raw soapstock and that it is identical with 3艂‐hydroxy‐3,4‐dehydro‐ ॆ ‐carotene, a dehydration product of lutein.