Carotenoid Composition in ‘Ataulfo’ Mango and Their Bioavailability and Bioconversion to Vitamin A

Ataulfo’ mango (Mangifera indica L.) is one of the most produced and consumed fruits in Mexico. This mango cultivar is claimed as a good source of carotenoids, however, its carotenoid profile has not been determined. In addition, bioaccesibility and bioavailability of carotenoids from fresh mangoes have not been tested. The present work included three experimental sections. In the first section the carotenoid profile of ‘Ataulfo’ mango was determined. The profile was composed of 25 carotenoids, and three were the most abundant. Then, the content of the major carotenoids was monitored during postharvest fruit ripening and correlated with the internal and external color values. The lowest and highest contents of all-trans-β-carotene, all-trans-violaxanthin dibutyrate and 9-cisviolaxanthin dibutyrate (major carotenoids) during the ripening process of ‘Ataulfo’ mangoes were 2.5-39.7, 0.2-15 and 0.2-7.5 μg/g FW, respectively. The content of the evaluated carotenoids highly correlated with external and internal a* and h° color values. Equations (R=0.86-0.94) to predict the content of the major carotenoids in ‘Ataulfo’ mangoes on the basis of their internal and external color values were obtained. In the second experimental section, the pulp of ‘Ataulfo’ mango at several stages of ripening was subjected to simulated in vitro digestion in absence or presence of chicken baby food (CBF), as dietary fat source, and the micellarization of β-carotene (BC) was evaluated. The micellarization of BC during simulated digestion significantly increased as the fruit ripened and when CBF was mixed with mango before digestion. BC-rich micelles generated during the digestion of fully ripened fruit and CBF were used to test the uptake of micellarized BC by monolayers of Caco-2 cells. Such cells incorporated 17% of BC contained in the test medium. In the last experimental section, vitamin A depleted rats (Wistar) were fed with cubes of fresh carrots or ‘Ataulfo’ mango pulp for 2 weeks. Both test meals provided the same amount of BC. After repletion the liver retinol was higher in the group fed with ‘Ataulfo’ mango (1642.3 μg retinol/liver) than in the group fed with carrots (1285.1 μg retinol/liver), suggesting that BC from ‘Ataulfo’ mango is more bioavailable than that from carrots. The obtained results demonstrated that ‘Ataulfo’ mango possesses a high content of BC, which is bioavailable and bioconverted to vitamin A. INTRODUCTION ‘Ataulfo’ mango (Mangifera indica L.) is a popular fruit in Mexico, commonly consumed at different ripening stages either alone or combined with other foods (Yahia et al., 2006a). The carotenoids are the pigments responsible for the typical yellow-orange 1245 Proc. 6 th International Postharvest Symposium Eds.: M. Erkan and U. Aksoy Acta Hort. 877, ISHS 2010 color of ripened mango fruit, with all-trans-β-carotene (BC) being one of the most abundant. The carotenoid composition of mango fruit depends on many factors, including genotype, stage of ripening and geographic origin. The carotenoids profile of ‘Ataulfo’ mango fruit have not been determined (Ornelas-Paz et al., 2007, 2008a; Yahia et al., 2007). In humans, the carotenoids exert protective effects against some types of cancer, age-related macular degeneration, and heart diseases. Some carotenoids, such as BC, also are precursors of vitamin A. Vitamin A deficiency, especially in children, remains as an important public health problem in Mexico and other Latin-American countries. Vitamin A is essential for vision, reproduction, growth, immune function, and general health for humans (Ornelas-Paz et al., 2009). The beneficial effects of carotenoids for human health and nutrition depend on the amount that is actually absorbed and/or metabolized by the organism. The absorption of carotenoids is a complex process that requires the transfer of the carotenoids from the food to mixed micelles for delivery to small intestinal epithelial cells and incorporation of the intact carotenoid or retinyl ester products into chylomicrons secreted into lymph (Ornelas-Paz et al., 2008b). Numerous factors affect these processes, including carotenoid speciation, food matrix, type and intensity of food matrix processing, and some components such as amounts of fat and fiber in the food and meal (West and Castenmiller, 1998). The effect of dietary fat and food matrix on carotenoids bioavailability is high. In vivo, ingested fat increases secretion of pancreatic lipases and bile, thereby enhancing the formation of micelles and bioaccessibility of carotenoids. Food matrix refers to the combined effects of all factors from foods that simultaneously promote or reduce the bioavailability of endogenous carotenoids. The different matrices in a plant food at different stages of ripening also are likely to affect carotenoid bioavailability. Marked qualitative and quantitative changes in carotenoids, organic acids, lipids, phenolic compounds, volatile compounds, non-structural and structural carbohydrates have been reported during the short duration of the ripening process of mango fruit. The effects of such compositional changes might modify the bioavailability of mango carotenoids at different stages of ripening. Existing data on the bioavailability of mango carotenoids are limited and contradictory. The accumulation of vitamin A in the liver of rats fed a diet with dried mango suggests that BC in this fruit is moderately bioavailable. However, supplementation with retinyl palmitate and mango was insufficient to correct vitamin A deficiency in Senegalese children (Carlier et al., 1992). The objectives of the present work were: 1) to identify the most important carotenoids in pulp of ‘Ataulfo’ mangoes and determine the relationship between content of these carotenoids and the external and internal color changes during fruit ripening; 2) to examine the influence of stage of ripening and dietary fat on the bioaccessibility of BC from mango using the coupled in vitro digestion and Caco-2 human cell model and; 3) to compare the bioavailability of mango carotenoids with that of carrots, the main source of dietary BC. MATERIALS AND METHODS In the first experimental section, the carotenoid profile of ‘Ataulfo’ mango was qualitatively and quantitatively investigated during the ripening process by HPLCAPcIMS (TOF) studies. A lot of ‘Ataulfo’ mango fruits (heterogeneous stage of ripening, uniform in size, freedom of blemishes and defects) were randomly evaluated for carotenoids content and internal and external tristimulus color. Regression analyses were carried out to obtain equations to predict the contents of the major carotenoids in mango pulp on the basis of external and internal color values. In the second experimental section, pulp from slightly ripe (SR), moderately ripe (MR) or fully ripe (FR) ‘Ataulfo’ mangoes were digested in vitro in the absence and presence of a chicken baby food (CBF) as source of exogenous fat to examine the impact of stage of ripening of mango and dietary fat on micellarization during digestion of BC. CBF contained 5.6% fat, 8.5% protein, and 0% fiber by weight. The uptake of BC in micelles generated during simulated digestion by Caco-2 human intestinal cells also was tested. In a separated set of digestion reactions