Please cite this article in press as: Codina-Torrella, I., et al., Characterization and comparison of tiger nuts (Cyperus esculen- tus L.) from different geographical origin. Physico-chemical characteristics and protein fractionation. Ind. Crops Prod. (2014), http://dx.doi.org/10.1016/j.indcrop.2014.11.007 ARTICLE IN PRESS G Model INDCRO-7633; No. of Pages 9 Industrial Crops and Products xxx (2014) xxx–xxx Contents lists available at ScienceDirect Industrial Crops and Products jo ur nal home p age: www.elsevier.com/locate/indcrop Characterization and comparison of tiger nuts (Cyperus esculentus L.) from different geographical origin Physico-chemical characteristics and protein fractionation Idoia Codina-Torrella, Buenaventura Guamis, Antonio J. Trujillo ∗ Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Centre Especial de Recerca Planta de Tecnologia dels Aliments (CERPTA), XaRTA, XiT, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain a r t i c l e i n f o Article history: Received 26 May 2014 Received in revised form 6 November 2014 Accepted 8 November 2014 Available online xxx Keywords: Tiger nuts Cyperus esculentus L. Physico-chemical characteristics Protein fractions SDS-PAGE gel a b s t r a c t In the present work, four types of marketable tiger nuts (Cyperus esculentus L.) from different geographical origins (Spain, Burkina Faso and Niger) were compared according to their physico-chemical character- istics and protein characterization. All batches presented a mixture of tubers of different shape, size and weight, of which the Spanish were the largest. Differences observed between their colors pointed to the variability in the skin color of tiger nuts in the market. The Spanish tubers were the richest in fat and pro- tein (35.21 and 8.45%, respectively), while similar values were observed in the African tubers (from 25.35 to 28.19% in fat and 3.28 to 7.32% in protein). Fairly low percentages of tannins and phytates were also detected in all of them (0.08–0.18 g/100 g and 9.31–22.55 mg/100 g, respectively). Similar results were obtained in the protein fractionation and characterization in tubers. These data showed the albumins to be the main protein fraction (82.23–91.93%), while globulins, prolamins and glutelins were represented by a remaining ∼3–7.5%. Albumins were characterized by a wide range of different molecular weight polypeptides (20, 25, 37, 55, 75 and ∼106 kDa), whereas in the other fractions, a lower number of bands was detected (at 18–78 kDa). These results suggested that physico-chemical characteristics and proxi- mate composition of tiger nut batches in the current market are the most variable parameters, which are mainly dependable on their geographical origin. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Tiger nuts (Cyperus esculentus L.) are little sweet tubers pro- duced in the roots of an edible perennial grass-like plant, which is widely found around the Mediterranean countries (Cos¸ kuner et al., 2002). These tubers are rich in energy (∼400–450 kcal/100 g), due to their content in starch and fat (26–30% and 21–25%, respec- tively). Major fatty acids of tiger nut oil are monounsaturated (>60%), which is why its profile is comparable to olive or hazelnuts oils (Dubois et al., 2007). Tiger nuts also present a good percentage in protein (3–8%) and fiber (8–10%), as well as in vitamins (E and C) and minerals (phosphorous and potassium) (Adejuyitan, 2011; Arafat et al., 2009; Bosch et al., 2005; Chinma et al., 2009; Chukwuma et al., 2010; Tigernuts Traders, 2014). Owing to their composition, different studies have pointed the suitability of these tubers for diabetics and people with digestive disorders, and also ∗ Corresponding author. Tel.: +34 581 32 92; fax: +34 93 581 20 06. E-mail address: toni.trujillo@uab.es (A.J. Trujillo). in the prevention of heart diseases (Borges et al., 2008; Chukwuma et al., 2010; Tigernuts Traders, 2014). For this reason, these tubers are attracting industry interest, and the development of new tiger nut derived products has already been reinforced. These tubers are sold as snack food, and their flour has also been successfully used in bakery, in by-meat products and as a flavoring agent in ice cream production (Sánchez-Zapata et al., 2012). However, tiger nuts are mainly used in the production of tiger nut drinks, non-alcoholic beverages that are traditionally made in Spain (horchata de chufa) and Africa (kunnun aya). Current studies have evidenced the importance of tiger nut characteristics in the production of these quality derived products in terms of their physicochemical char- acteristics and nutritional profile, but despite most of these tubers being characterized and submitted to the sanitary official controls, the quality characteristics of some batches are still in doubt (Addy and Teshola, 1984; Bosch et al., 2005; Ejoh and Ndjouenkeu, 2007; Oladele and Aina, 2007; Sánchez-Zapata et al., 2010). Owing to all of this, the objective of the present work was to compare the quality characteristics of tiger nuts from different geo- graphical origin which are commercialized in the European market http://dx.doi.org/10.1016/j.indcrop.2014.11.007 0926-6690/© 2014 Elsevier B.V. All rights reserved.