Non-starch polysaccharide composition of two cultivars of banana (Musa acuminata L.: cvs Mysore and Nanica ˜o) Beatriz Rosana Cordenunsi * , Tania Misuzu Shiga, Franco Lajolo Laborato ´rio de Quı ´mica, Bioquı ´mica e Biologia Molecular de Alimentos, Departamento de Alimentos e Nutric ¸a ˜o Experimental, FCF, Universidade de Sa ˜o Paulo, Avenida Lineu Prestes 580, Bloco 14, CEP 05508-900, Sa ˜o Paulo SP, Brazil Received 14 February 2007; received in revised form 30 March 2007; accepted 4 May 2007 Available online 16 May 2007 Abstract Fruits represent a rich source of soluble and insoluble ﬁbre, and the pectin is the most common and known soluble fraction from the cell wall solubilization occurring during fruit ripening. Banana fruit, for example, is one of the most consumed fruits in the world, but its non-starch polysaccharide composition is almost unknown. Despite few works have been carried out about the enzymes concerning cell wall loosening focusing banana ripening, there is no knowledge about the composition of the banana cell wall. Moreover, there is no information about the inﬂuence of the cultivar in that composition. Nanica ˜o and Mysore cultivars were chosen for this work because of their diﬀerential accumulation of both starch during development and amounts of total ﬁbre in the ripe fruit. Nanica ˜o and Mysore had their ﬁbres subfractioned and their composition analysed. Results showed that the cultivars are distinct not only in terms of starch and soluble sugars accumulation, but also in non-starch polysaccharides amounts and composition. Non-starch polysaccharides are sim- ilar in total amounts in both banana cultivars (3.5), but substantially diﬀerent in the content of CDTA and NaOH-4M soluble fractions and also in the molecular mass distribution of WSP and CDTA. Nanica ˜o has more calcium-linked pectin than Mysore, which in turn is richer in hemicellulose-like polysaccharides. Both cultivars likewise cereals polysaccharides seem to be composed of galacturonans and arabinoxylans. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Banana; Cell wall; Dietary ﬁbre; Non-starch polysaccharides 1. Introduction Dietary ﬁbre (DF) is a collective term for a variety of plant substances that are resistant to digestion by human gastrointestinal enzymes. Edible plant cell wall polysaccha- rides, lignin and associated substances make up the bulk of the ﬁbre fraction. Based on this deﬁnition, resistant starch, wheat bran, oat bran and fructo-oligosaccharides are included in the category of ﬁbre (Englyst & Englyst, 2005). DF terminology and classiﬁcation can diﬀer, consid- ering the various countries and the knowledge about food components resistant to the human digestion. For instance, the term ‘‘non-starch polysaccharides’’ has been used instead DF, in the United Kingdom, in nutritional label- ling. Recently, ‘‘total ﬁbre’’ was classiﬁed as Dietary Fibre and Functional Fibre. The former was deﬁned as ‘‘the non- digestible carbohydrate and lignin that are intrinsic and intact in plants’’ and the latter, ‘‘isolated, non-digestible carbohydrates that have beneﬁcial eﬀects in humans’’ (Jen- kins, Marchie, Augustin, Ros, & Kendall, 2004). In spite of its resistance to human digestion, DF is far from being inert. Depending on its components and conse- quent solubility in water, it is classiﬁed to soluble or insol- uble forms which can provide many health beneﬁts. Because of its multiple components with diﬀerent physical and chemical properties, DF has the capacity to either sorb or bind many harmful substances, as cholesterol, glucose, hydrochloric acid and heavy metals, reducing their levels in the organism. For this, DF consumption has been linked 0144-8617/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.carbpol.2007.05.009 * Corresponding author. Tel.: +55 11 30913656; fax: +55 11 38154410. E-mail address: hojak@usp.br (B.R. Cordenunsi). www.elsevier.com/locate/carbpol Available online at www.sciencedirect.com Carbohydrate Polymers 71 (2008) 26–31