Control of postharvest anthracnose of banana using a new edible composite coating Mehdi Maqbool, Asgar Ali * , Senthil Ramachandran, Daniel R. Smith, Peter G. Alderson School of Biosciences, Faculty of Science, The University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia article info Article history: Received 1 March 2010 Received in revised form 1 June 2010 Accepted 2 June 2010 Keywords: Colletotrichum musae Disease incidence Edible coatings Musa acuminate Mycelial growth Physico-chemical characteristics abstract Anthracnose is a postharvest disease of banana caused by the fungus Colletotrichum musae that results in major economic losses during transportation and storage. For the management of banana anthracnose, antifungal effects of Arabic gum (AG) (5, 10,15 and 20%), chitosan (CH) (1.0%), and the combination of AG with CH were investigated in vitro as well as in vivo. CH at 1.0% and 1.5% had fungicidal effects on C. musae. AG alone did not show any fungicidal effects while the combination of 1.0% CH with all tested AG concentrations had fungicidal effects. However, the potato dextrose agar (PDA) medium amended with 10% AG incorporated with 1.0% CH showed the most promising results among all treatments in sup- pressing the mycelial growth (100%) and conidial germination inhibition (92.5%). In vivo analysis also revealed that 10% AG incorporated with 1.0% CH was the optimal concentration in controlling decay (80%), showing a synergistic effect in the reduction of C. musae in artificially inoculated bananas. The 10% AG incorporated with 1.0% CH coatings significantly delayed ripening as in terms of percentage weight loss, fruit firmness, soluble solids concentration and titratable acidity. The results showed the possibility of using 10% Arabic gum incorporated with 1.0% chitosan as a biofungicide for controlling postharvest anthracnose in banana. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction Banana is a popular fruit worldwide due to its flavor, texture, nutritional value and convenience, being easy to peel and eat (Robinson, 1996). However, banana is susceptible to several diseases resulting in massive and extensive postharvest losses during transportation and storage (Basel et al., 2002). Anthracnose, caused by the fungus Colletotrichum musae (Berk. & M.A. Curtis) Arx, is the most important postharvest disease of banana that can result in 30e40% losses of marketable fruit (Ranasinghe et al., 2003). Anthracnose is a latent infection where fungal spores infect immature banana in the field but symptoms occur as peel blemishes, as black or brown sunken spots of various sizes on fruit that may bear masses of salmon-colored acervuli with their asso- ciated conidia on the fruit peel after ripening (Ranasinghe et al., 2005). Thus, any potential control measure which can effectively delay symptoms of anthracnose infection would have an important role in extending the shelf life of banana fruit during storage. Synthetic fungicides e.g. benomyl and thiabendazole (TBZ) are the most commonly used method for controlling post- harvest diseases (Khan et al., 2001). However, persistent use of these fungicides has resulted in the emergence of resistant strains of C. musae (de Lapeyre de Bellaire and Chilin-Charles, 2008). In addition, there is concern that residues of chemical fungicides may cause health problems e.g. carcinogenic risk (Wilson et al., 1997). The use of chemical fungicides to control postharvest diseases of fruit is scheduled to be phased out worldwide by year 2020 under the terms of the Montreal Protocol (Anonymous, 2003). Therefore, there has been an increasing pressure on the banana industry to minimize the use of synthetic fungicides and discover sustainable non-chemical alternative fungicides for controlling postharvest diseases. A novel approach to extend postharvest shelf life is the use of edible coatings of natural antimicrobial compounds (Baldwin et al., 1995). Edible coatings create a modified atmosphere around the fruit by providing a semi-permeable barrier to O 2 and CO 2 , thereby reducing respiration and oxidation reaction rates (Nisperos- Carriedo, 1994). Lipids, proteins and polysaccharides are the major constituents of edible films and coatings, obtained from a variety of agricultural commodities and/or wastes of the food production industry. Polysaccharide-based coatings have been used widely to extend the shelf life of fruits and vegetables (Nisperos-Carriedo, 1994). Arabic gum (AG) is a polysaccharide widely used in the indus- trial sector as a common food additive (Motlagh et al., 2006). It has * Corresponding author. Tel.: þ60 3 8924 8219; fax: þ60 3 8924 8018. E-mail address: Asgar.Ali@nottingham.edu.my (A. Ali). Contents lists available at ScienceDirect Crop Protection journal homepage: www.elsevier.com/locate/cropro 0261-2194/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.cropro.2010.06.005 Crop Protection 29 (2010) 1136e1141