Nutritional value of non-conventional vegetables prepared by family farmers in rural communities

Valor nutricional de hortaliças não convencionais preparadas por agricultores familiares em comunidades rurais

ABSTRACT:

Four most consumed non-conventional vegetables were analyzed raw and after cooking techniques routinely used by family farmers: ora-pro-nobis (Pereskia aculeata Mill.); wild mustard (Sinapis arvensis L.), serralha (Sonchus arvensis L), and capiçova (Erechtites valeriana). Chemical composition was determined according to AOAC. Vitamin C, vitamin E and carotenoids were determined by high-performance liquid chromatography, and phenolic compounds and minerals by spectrophotometry. Vitamin E and carotenoids concentrations were higher in stir fried wild mustard (7.68 mg.100 g^-1 and 7.45 mg.100 g^-1, respectively). Cooking reduced some minerals concentration in the non-conventional vegetables, but increased vitamins and carotenoids concentrations. The vegetables presented high content of minerals but low protein concentration and total energy content. Non-conventional vegetables can be considered of excellent nutritional value and frequent consumption of these vegetables can contribute to improve the feeding of farmers and their families.

Key words: vitamins; HPLC; agroecology; food sovereignty