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

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 highperformance 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. RESUMO: Quatro hortaliças não convencionais mais consumidas foram analisadas cruas e após as técnicas de cocção utilizadas rotineiramente pelos agricultores familiares: ora-pro-nobis (Pereskia aculeata Mill.); mostarda selvagem (Sinapis arvensis L.), serralha (Sonchus arvensis L) e capiçova (Erechtites valeriana). A composição química foi determinada de acordo com a AOAC. A vitamina C, vitamina E e os carotenoides foram determinados por cromatografia líquida de alta eficiência (CLAE), e compostos fenólicos e minerais foram determinados por espectrofotometria. As concentrações de vitamina E e carotenoides foram maiores na mostarda selvagem (7,68 mg.100 g -1 e 7,45 mg.100 g -1 , respectivamente). A cocção reduziu a concentração de alguns minerais nas hortaliças não convencionais, mas aumentou as concentrações de vitaminas e carotenoides. As hortaliças apresentaram alto teor de minerais, mas baixa concentração protéica e valor energético total. As hortaliças não convencionais podem ser consideradas de excelente valor nutricional. O consumo frequente dessas hortaliças pode contribuir para melhorar a alimentação dos agricultores e suas famílias. Palavras-chave: vitaminas, CLAE, agroecologia, soberania alimentar. RURAL EXTENSION

Chemical Composition and Nutritional Value of Three Sonchus Species

“…Regarding the content of vitamin E, the results found in the present study were below those found in S. asper (49 μ g/100 g) by Oliveira [ 44 ]. The α-tocopherol content was also higher in S. oleraceus (197 μ g/100 g) and S. asper (205 μ g/100 g); although in this study, these compounds were analyzed in dry matter.…”

Nutritional and Phytochemical Composition of Mediterranean Wild Vegetables after Culinary Treatment

“…Moreover, variations in the cooking conditions, such as maximum temperature reached, cooking time, pH, surface/volume relation, water used, oxygen and light presence, matrix and/or food type, as well as compounds sensitivity to these factors can influence the final composition [26,27]. Some research works have been conducted on the analysis of nutritional and phytochemical composition, as well as antioxidant activity of traditionally consumed wild edible plants all over the world [28][29][30][31][32][33][34][35][36][37][38]. For example, Trichopoulou et al [28] reported data of the nutritional composition of Cretan pies elaborated with cultivated and wild vegetables (such as Rumex spp.…”

Knowledge, Nutritional Value and Uses of Some Non-Conventional Plant Foods

“…They are easy and cheap plants to find and can be a low-cost vegetable alternative. Moreover, they are an option to escape the food monotony that the food industry imposes, for the perpetuation of good eating habits [8]. In addition, the intake of these non-conventional vegetables is known for their pharmacological properties.…”