Determinação do teor de carotenoides totais em doze genótipos de batata- doce (Ipomoea batatas (L.) Lam.) e sua variação durante a cocção

Abstract

Sweet potato (BD) is one of the main food products in Mozambique and is used as a vehicle for vitamin A biofortification. The International Potato Centre (CIP) is the entity responsible for biofortification programmes through genetic improvement and has generated several sweet potato genotypes (GBD). One of the necessary parameters to be evaluated in the is the carotenoid content. The main aim of this study was to determine the carotenoid content (CT) in twelve GBD and its variation during cooking. For this purpose twelve GBD were obtained from the CIP: Olga, MGSGR18100-11, MGSGR18012-16, Nsantimuni, MUSG18021- 20, Alisha, Namanga, MGSG17005-10, Victória, Ken, Palmira and MGSG17009-19. A completely causalised experimental design (DCC) with two treatments: GBD and cooked GBD. In addition, the colour of the pulp was characterised; moisture content (HU%), soluble solids (TSS) and pH were determined for fresh GBD. The content was determined using the spectrophotometry method at 450 nm in the fresh and cooked GBD. Finally, the loss of total carotenoids due to cooking (PCTPC%) was assessed. The colour of the pulp was purplein the GBDs Olga, MGSGR18100-11 and MGSGR18012-16; white in the GBDs Nsantimuni and MUSG18021- 20; yellow in the GBDs Alisha, Namanga and MGSG17005-10; and orange in the GBDs Victória, Ken, Palmira and MGSG17009-19The GBD in natura, with purple, white, yellow and orange flesh, had an average of 71.37%, 74.62%, 72.42% and 70.06% HU% respectively; 10.37 oBrix; 9.07oBrix; 8.71oBrix and 9.28oBrix of TSS respectively; 6.14; 6.12; 6.54 and 6.61 of pH respectively; 261.55 μg/g; 177.15 μg/g; 569.63 μg/g and 726.14 μg/g of TC content content respectively. The GBD in cooked form, with purple, white, yellow and orange flesh had on average 223.69 μg/g; 74.47 μg/g; 467.02 μg/g and 637.57 μg/g of TC content respectively. After cooking, the GBD of purple, white, yellow and orange pulp had an average of 17.2 per cent, 57.77 per cent; 21.56% and 12.76% PCTPC% respectively. The sweet potato genotype has an influence on the parameters of moisture, total soluble solids, pH and total carotenoids. The levels of total carotenoid content of sweet potato genotypes varies according to the colour of the flesh, i.e. orange-fleshed genotypes have a higher total carotenoid content, followed by yellow-fleshed genotypes. while purple-fleshed and white-fleshed genotypes have lower total carotenoid content. The cooking process reduces the total carotenoid content o of colour.sweet potato genotypes regardless of flesh colour, however, the white-fleshed genotypes show a greater loss of total carotenoids.