Development of anti-microbial jute fabrics via in situ formation of cellulose–tannic acid–metal ion complex Asha Higazy a, * , Mohamed Hashem a, * , Ali ElShafei b , Nihal Shaker c , Marwa Abdel Hady a a Textile Division, National Research Centre, Dokki, Cairo, Egypt b Division of Genetic Engineering and Biotechnology, National Research Centre, Dokki, Cairo, Egypt c Faculty of Science, Al-Azhar University (Girls), Cairo, Egypt article info Article history: Received 26 September 2009 Accepted 8 October 2009 Available online 15 October 2009 Keywords: Anti-microbial Cellulose Food preservation Jute fabric Metal complex abstract Although both tannic acid and metal ions serve as anti-microbial agent, they are inactive towards sev- eral kinds of microorganisms. The current work aims at examine the technical feasibility of using tan- nic acid to form in situ complex with environmentally save metal ions onto jute cellulose. Three kind of metal salts were selected, namely, AgNO 3 , ZnSO 4 , Zr(SO 4 ) 2 4H 2 O. Cellulose–tannic acid–metal com- plexes were formed in situ by treatment the jute fabric with tannic acid then allow the treated sam- ples to absorb the metal ions from its aqueous metal salt solution. The treated fabrics were monitored for anti-microbial activity and metal ion content as well as the washing durability. The effect of both tannic acid and metal salt concentration on the anti-microbial activity of the treated jute fabric as well as washing durability were investigated. Current data disclosed that jute fabrics treated with tan- nic acid–metal complex formed in situ show enhanced anti-microbial properties compared with those sample treated with tannic acid or metal ions separately and at the same concentrations. The results show also that both antibacterial and antifungal properties of the jute fabric treated with tannic– metal complexes follow the order: tannic acid—Zn > tannic acid—Zr > tannic acid—Ag It was found also that the washing durability of jute fabric treated with tannic acid–metal complex was very high and depends on the type of metal ion used in complexation and follows the order: tannic acid—Zn > tannic acid—Ag > tannic acid—Zr: Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Anti-microbials gain interest from both academic research and industry due to their potential to provide quality and safety bene- fits to many materials. Anti-microbial packaging is the packaging system that is able to kill or inhibit spoilage and pathogenic micro- organisms that are contaminating foods (Church & Parsons, 2007; Devlieghere, Vermeiren, Jacobs, & Debevere, 2000; El-Refaie, Worley, & Broughton, 2007; Ghosh, Srivatsa, Nirmala, & Sharma, 1977; Han, 2003; Weng & Hotchkiss, 1993). Microbial contamination reduces the shelf life of foods and increases the risk of food-borne illness. The demand for minimally processed, easily prepared, and ready to eat ‘‘fresh” food products, poses major challenges for food safety and quality. Application of anti-microbial treatment in food packaging is gaining interest from researchers due to its potential to provide quality, safety benefits and to extend the shelf life of the food. Anti-microbial food packag- ing promotes safety by reducing the rate of growth of specific microorganisms by direct contact of the package with the surface of foods (Coma, Sebti, Pardon, Deschamps, & Pichavant, 2001; Ming, Weber, Ayres, & Sandine, 1997; Weng & Hotchkiss, 1993). The ideal anti-microbial polymer should possess the following characteristics: (i) easily and inexpensively synthesized, (ii) stable in long-term usage and storage at the temperature of its intended application, (iii) not soluble in water for a water disinfection appli- cation, (iv) does not decompose to and/or emit toxic products, (v) should not be toxic or irritating to those who are handling it, (vi) can be regenerated upon loss of activity, and (vii) biocidal to a broad spectrum of pathogenic microorganisms in brief times of contact (Church & Parsons, 2007; Jay, 1996; Scannell et al., 2000). A tremendous effort has been made over the last decade to develop and test films with anti-microbial properties to improve food safety and shelf life. Some polymers are inherently anti- microbial, and have been used in films and coatings. Cationic polymers such as chitosan promote cell adhesion. Because charged amines interact with negative charges on the cell 0144-8617/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.carbpol.2009.10.019 * Corresponding authors. Fax: +20 233370931. E-mail addresses: gelfeky@hotmail.com (A. Higazy), mmhashem@ncsu.edu (M. Hashem). Carbohydrate Polymers 79 (2010) 890–897 Contents lists available at ScienceDirect Carbohydrate Polymers journal homepage: www.elsevier.com/locate/carbpol