Carotenoids and provitamin A value of some Brazilian sweet potato cultivars (Ipomoea batatas Lam.) / Carotenoides e valor pro-vitaminico A de alguns cultivares de batata-doce (Ipomoea batatas Lam.)

RESUMO

In order to determine the carotenoid content and provitamin A value of raw and cooked sweet potatoes, ten cultivars from "Instituto Agronomico de Campinas" and "Centro Nacional de Pesquisa de Hortalicas da Empresa Brasileira de Pesquisa Agropecuaria - EMBRAPA" were analysed. The techniques used included open column chromatography and spectrophotometry. Seven carotenoids were identified Beta-carotene-5,6,5'6'-diepoxide; Beta-carotene-5,6-epoxide; luteochrome; alfa-zeacarotene; Beta-zeacarotene and aurochrome. Beta-carotene was the main carotenoid of the following cultivars Centennial, Heart Gold, Anapolis, Acadian, Morada Inta, Vineland Bush and clone CNPH. Luteochrome was the principal carotenoid of Monalisa, IAC-2-71 and SRT-252 cultivars. For raw roots the vitamin A value varied from 1 retinol equivalents/100g for IAC-2-71 cultivar to 3,703 retinol equivalents/100g for Acadian. For cooked roots, Acadian cultivar presented the highest provitamin A activity, with 4,021 retinol equivalents/100g. The loss of Beta-carotene due to cooking varied from 4.5% to 17.8% in accordance with the kind of cultivar