Ascorbic acid content in exotic fruits: A contribution to produce quality data for food composition databases Ana Valente, Tânia Gonçalves Albuquerque, Ana Sanches-Silva, Helena S. Costa ⁎ Departamento de Alimentação e Nutrição, Instituto Nacional de Saúde Doutor Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisbon, Portugal abstract article info Article history: Received 30 November 2010 Accepted 11 February 2011 Keywords: Ascorbic acid Exotic fruits HPLC Food composition databases Dietary reference intake Ascorbic acid (AA) is a water-soluble vitamin mainly present in fruits and vegetables. Food Composition Databases (FCDB) provide detailed information on nutritionally important components in foods. However, in some FCDB there is a significant lack of information on vitamin C content. The aim of this study is to produce new data for FCDB by measuring the AA content in 26 types of exotic fruits and to evaluate the nutritional value of these fruits as a source of vitamin C. In this study, the analytical method used to measure ascorbic acid content is an economic, rapid and previously validated High Performance Liquid Chromatography (HPLC) method. Ascorbic acid content per 100 g of edible portion ranged between 0.925 ± 0.018 mg for kiwano and 117 ± 1.64 mg for arbutus. For all the analyzed exotic fruits and considering a mean daily consumption of 100 g/day, twelve of them provide more than 30% of the Dietary Reference Intake. About a quarter of the analyzed exotic fruits are not found in any of the five FCDB considered in this study. The worldwide global market is expanding the production and consumption of fresh fruits and vegetables, mostly exotic, increasing the need of updating the food composition databases with high quality data. The analytical results obtained in this study are an important source of reliable data to be included in the Portuguese food composition database. © 2011 Elsevier Ltd. All rights reserved. 1. Introduction Vitamin C is one of the most important water-soluble vitamins, naturally present in foods, especially in fruits and vegetables, and is widely used as a food additive and as an antioxidant (Pénicaud, Peyron, Bohuon, Gontard & Guillard, 2010). Antioxidants are sub- stances that can prevent or delay oxidative damage of lipids, proteins and nucleic acids by reactive oxygen species (Insel, Turner, & Ross, 2002). Vitamin C is a dietary antioxidant required as a co-factor for many enzymes. The reduced form of vitamin C, L-ascorbic acid, is the main biologically active form of this vitamin and it is an effective antioxidant due to its high electron-donating power and ready conversion back to the active reduced form. Several epidemiological studies showed that subjects with a higher intake of vitamin C have lower risk for several chronic diseases, namely heart disease, diabetes, cancer or neurodegenerative diseases (Jacob & Sotoudeh, 2002). Exotic fruits are those whose use was restricted to people living in limited geographic areas (Oliveira, Lopes, Cabral, & Eberlin, 2006; Aparecida de Assis et al., 2009). Now, they have become quite common foods in countries that do not traditionally produce these types of fruits. The production of exotic fruits has increased in the last years due to their attractive sensorial properties and because they are claimed to be good source of vitamins, such as C and E, and bioactive compounds, as polyphenols or carotenoids (Vinci, Botrè, Mele, & Ruggieri, 1995; Gonzalez-Aguilar, Villa-Rodriguez, Ayala-Zavala & Yahia, 2010). In Portugal, the production of exotic fruits has increased in the last years due to a higher demand from consumers. However, in Portugal only a few kinds of exotic fruits are produced. Madeira Island is a Portuguese region with excellent climate conditions for the production of some exotic fruits, such as, avocado, banana and passion fruit. Azores Island is also a good region to grow exotic fruits, like pineapple. Another region is the Algarve, in the south of Portugal, where its climate, low humidity and little limestone soils with good drainage, gives this region of the country optimal growing conditions for exotic fruits, namely for avocado and kiwifruit. Food composition databases (FCDB) provide detailed information on nutritionally important components in foods. However, in some FCDB there is a significant lack of information on vitamin C content, especially for exotic fruits. FCDB are never complete and require constant update due to the introduction of new foods into the food chain (new cultivars/ breeds, processed foods, and imported foods), newly discovered food components that are associated with health effects, and constant improvements in methods to analyze foods or food components (Pennington, 2008). Data on food composition are essential for a variety of purposes in many different fields of work, such as the assessment of nutrient intakes, to assess the effect of diet on health and disease, and to support the development of dietary guidelines for population groups Food Research International 44 (2011) 2237–2242 ⁎ Corresponding author at: Instituto Nacional de Saúde Doutor Ricardo Jorge, Departamento de Alimentação e Nutrição, Av. Padre Cruz, 1649-016 Lisbon, Portugal. Tel.: +351 217 519 267; fax: +351 217 508 153. E-mail address: helena.costa@insa.min-saude.pt (H.S. Costa). 0963-9969/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodres.2011.02.012 Contents lists available at ScienceDirect Food Research International journal homepage: www.elsevier.com/locate/foodres