Retention of provitamin A carotenoids during postharvest ripening and processing of three popular musa cultivars in south-western Uganda
Abstract
Banana and plantain (Musa spp.) form an important part of the diet of communities in Uganda. Despite preliminary indications that some cultivars could be good sources of provitamin A carotenoids (pVACs), vitamin A deficiency remains a health problem in banana-dependent regions of Uganda. The most popular Musa cultivars in southwestern Uganda include two East African highland bananas (AAA-EA) ‘Entaragaza’ and ‘Mbwazirume’, and one plantain (AAB) ‘Manjaya-Gonja’. The AAA-EAs are mostly eaten steamed, while the plantain is generally roasted. Retention levels of pVACs during fruit ripening and processing of these popular cultivars were determined by high performance liquid chromatography (HPLC). Highest levels were found for ripe ‘Entaragaza’ (7319 µg/100 g dw), fully ripe ‘Mbwazirume’ (6493 µg/100 g dw) and fully ripe ‘Manjaya-Gonja’ (13,377 µg/100 g dw). Steamed ‘Entaragaza’ and ‘Mbwazirume’ retained more than 90% of total pVACs. Roasting, deep-frying and steaming of ‘Manjaya-Gonja’ resulted in substantial loss of pVACs, with the highest loss (58.5%) observed after deep-frying in fully refined vegetable oil. All-trans β- and all-trans α-carotene constituted over 87% of the total carotenoids. The plantain ‘Manjaya-Gonja’ had a significantly higher proportion of β-carotene, while the AAA-EAs had significantly higher proportions of α-carotene. Although no cis α-carotenes and only negligible levels of cis β-carotene were observed during ripening, after processing the proportion of cis-carotenoids increased to about 10%. Retinol Activity Equivalents (RAE) in the processed products ranged from 97.91 to 138.16 µg/100 g edible portion. Therefore, consumption of 100 g of the tested products theoretically meets 24-35 and 16-20% of the vitamin A RDAs of a preschooler and a woman of reproductive age. Although steaming retains the highest levels pVACs, the tested Musa cultivars can make substantial contribution to vitamin A requirements of vulnerable groups whether roasted, boiled or fried.
Citation
Ekesa, B.; Mirroir, C.; Blomme, G.; van den Bergh, I.; Davey, M.W. Retention of provitamin A carotenoids during postharvest ripening and processing of three popular musa cultivars in south-western Uganda. Acta Horticulturae (2013) 986: 319-330. [International ISHS-ProMusa Symposium on Bananas and Plantains: Towards Sustainable Global Production and Improved Use]