Statistical Differentiation of Bananas According to Their Mineral Composition MARKUS PAUL FORSTER, † ELENA RODRI ÄGUEZ RODRI ÄGUEZ, † JACINTO DARIAS MARTI ÄN, ‡ AND CARLOS DI ÄAZ ROMERO* ,† Department of Analytical Chemistry, Nutrition and Food Science, and Department of Chemical Engineering, University of La Laguna, 38201 Santa Cruz de Tenerife, Spain The concentrations of Na, K, Ca, Mg, Fe, Cu, Zn, and Mn were determined in banana cultivars Gran enana and Pequen ˜ a enana cultivated in Tenerife and in cv. Gran enana bananas from Ecuador. The mineral concentrations in the bananas from Tenerife and from Ecuador were clearly different. The cultivar did not influence the mineral concentrations except in the case of Fe. Variations according to cultivation method (greenhouse and outdoors) and farming style (conventional and organic) in the mineral concentrations in the bananas from Tenerife were observed. The mineral concentrations in the internal part of the banana were higher than those in the middle and external parts. Representation of double log correlations K-Mg and Zn-Mn tended to separate the banana samples according to origin. Applying factor and cluster analysis, the bananas from Ecuador were well separated from the bananas produced in Tenerife, and therefore, these are useful tools for differentiating the origin of bananas. KEYWORDS: Mineral composition; banana; cultivars; cultivation method; organic; conventional; mineral intake; Tenerife; Ecuador INTRODUCTION Approximately 70% of the total world production of bananas comes from Latin America, and mainly Ecuador produces about 30% of all the bananas from Latin America. The banana is also one of the most important agricultural products of the Canary Islands, contributing 3.4% to the world trade. The cultivation of bananas is very important in the Canary Islands because of their high consumption, as well as for economic and traditional reasons. Approximately 20% of agricultural land in the Canary Islands is used for banana production, and Tenerife represents a third of the total production. The nutritional value of bananas is high, as its consumption is very healthy for all ages (1). Basically, there are two banana cultivars produced in the Canary Islands: Gran enana and Pequen ˜a enana, each belonging to Musa acuminata AAA (sub-group cavendish) and included in the family of Musaceae. Organic bananas are produced according to the European regulations of ecological plantation (2), which regulates the use of fertilizers and antiparasitic products, imposes water regulations, and controls the production and commercialization. Each year in the Canary Islands about 500 tons of bananas are produced according to these regulations. Most ecological plantations are less than one hectare and the main problems are the parasites and less effective fertilization, which increase the costs, especially the labor. The chemical characterization of food products can permit their differentiation according to geographic origin. Research on the determination of the geographic origin or quality brand of food products is a very active area for the application of chemometric classification procedures (3). Objective physico- chemical parameters are currently used for the classification and differentiation of food samples. The chemical composi- tion and the nutritive value of bananas is influenced by many factors such as the production area, cultivar, soil and climate, agricultural practices, the quality of water for irrigation, and storage and commercialization conditions. It is scient- ifically accepted that the mineral and trace metal composition of fruits and vegetables is a distorted reflection of the trace mineral composition of the soil and environment in which the plants grow. Therefore, it can be used as a criteria to distinguish the geographic origin of bananas, as the mineral composition of soils changes depending on the region consid- ered. We determined the concentrations of Na, K, Ca, Mg, Fe, Cu, Zn, and Mn in bananas from Tenerife and Ecuador in order to differentiate them. The contribution to the human diet mineral intake due to the current consumption of bananas in the diet was estimated. In addition, the bananas from Tenerife were classified according to the cultivation method and farming style using the mineral contents. A statistical study of correlation, factor analysis, and cluster analysis was carried out on the mineral data in order to separate the banana samples into homogeneous groups. * Corresponding author (phone 00 34 922 318049; fax 00 34 922 318003; e-mail cdiaz@ull.com). † Department of Analytical Chemistry, Nutrition and Food Science. ‡ Department of Chemical Engineering. 6130 J. Agric. Food Chem. 2002, 50, 6130-6135 10.1021/jf0255578 CCC: $22.00 © 2002 American Chemical Society Published on Web 09/14/2002