Caracterização físico-química das folhas de batata-doce ‘brs anembé’ e ‘brs cotinga’ para uso na alimentação humana

Abstract

Sweet potato is a widely consumed vegetable worldwide, and its aerial part, considered a leafy vegetable, is used in human food, particularly in African countries. In Brazil, this practice has declined, but there is currently a revaluation of its consumption due to the nutritional quality of the leaves, their high yield, drought tolerance, lower production cost, and wide adaptation to different soil and climatic conditions compared to other vegetables. With this in mind, this research aimed to evaluate the leaves of two sweet potato cultivars developed by Embrapa, namely BRS Anembé and BRS Cotinga, on two different harvest days, to identify their potential as a vegetable or supplement in human nutrition. The study examined their proximate composition, soluble solids, pH, titratable acidity, as well as color, dry matter, chlorophyll, and vitamin C content. In early October, the 'BRS Anembé' leaves had average protein, lipid, ash, and carbohydrate contents of 20.57%, 2.56%, 8.52%, and 68.64%, respectively. By the end of October, these values were 19.03%, 2.36%, 8.54%, and 69.96%. For 'BRS Cotinga', the protein, lipid, ash, and carbohydrate contents were 20.44%, 2.43%, 8.30%, and 69.90% in early October, while by the end of October, these contents were 19.16%, 2.24%, 8.77%, and 68.57%, respectively. The 'BRS Anembé' leaves had a pH of 6.22 and titratable acidity of 0.196 g 100 g-1 in the first harvest, and a pH of 6.20 and titratable acidity of 0.180 g 100 g-1 in the second harvest. The 'BRS Cotinga' had a pH of 6.37 and titratable acidity of 0.224 g 100 g-1 in the first harvest, and a pH of 6.40 and titratable acidity of 0.152 g 100 g-1 in the second harvest. The 'BRS Anembé' leaves had an average soluble solids content of 1.71 ºBrix, and the 'BRS Cotinga' leaves had a content of 1.63 ºBrix, in early October. In the color analysis, there was a significant difference between the harvest days for the three parameters: luminosity (L*), chromaticity (C*), and hue angle (ho), presenting darker green leaves by the end of October. The 'BRS Anembé' and 'BRS Cotinga' had average dry matter values of 17.91% and 18.42%, respectively, in early October, and 17.85% and 17.34%, respectively, by the end of October. For the 'BRS Anembé' cultivar, the results for chlorophyll in early and late October were 50.54 μg g-1 and 47.36 μg g-1, respectively, while for the 'BRS Cotinga' cultivar, the results were 41.77 μg g-1 and 44.95 μg g-1, respectively. As for vitamin C content, the 'BRS Anembé' cultivar had levels of 38.41 mg 100 g-1 in early October and 37.95 mg 100 g-1 at the end of October, while the 'BRS Cotinga' cultivar had levels of 40.40 mg 100 g-1 in early October and 40.86 mg 100 g-1 at the end. The sweet potato leaves from the 'BRS Anembé' and 'BRS Cotinga' cultivars, harvested in both early October after a dry period and late October after a rainy period, did not show significant changes in post-harvest and nutritional qualities. These results emphasize the viability of using the aerial part of the sweet potato as a vegetable or supplement in human nutrition, highlighting its potential as a nutritional source.