Production of antimicrobial membranes loaded with potassium sorbate using a supercritical phase separation process

The production of antimicrobial packaging is one of the most interesting challenges in the food industry; its scope is to prolong the shelf life of a food maintaining its safety and freshness. The major limitation of traditional techniques used to produce antimicrobial packaging, is the difficulty in controlling the release of the active agent from the device to the food surface. In this work, a supercritical phase inversion process has been tested to produce potassium sorbate (PS) loaded cellulose acetate (CA) membranes, to be inserted in food packaging. The membranes have been obtained at different process conditions (pressures 150-250 bar, temperatures 35-55 degrees C) and at different polymer concentrations (10, 15 and 20% w/w). PS to CA weight ratio has been maintained constant at 5% w/w for all the formulations. The best process parameter combination to obtain the longest PS release time (about 325 min) was 250 bar and 35 degrees C. Industrial relevance: The production of antimicrobial active packagings is one of the most attractive challenges in the food industry also catalyzed by consumers' demand for natural and safe foods and for environmental protection [1]. Antimicrobial food packaging reduces, inhibits or retards the growth of microorganisms that may be present in the food or packaging material itself [2], to extend the shelf life of the packed food. The most desired property is the controlled release of the antimicrobial agent to the food surface [3-6]. This characteristic is influenced by the technique used to produce the film. To overcome conventional processes limitations, it could be possible to use supercritical assisted processes, taking advantage of the properties of supercritical fluids, such as negligible surface tension, high diffusivity and low viscosity. In particular, a supercritical phase separation process has been successfully proposed to produce loaded polymeric membranes to be inserted in food packaging. [1] C.A. Campos, L.N. Gerschenson, S.K. Flores, Development of edible films and coatings with antimicrobial activity, Food Bioprocess Technol. 4 (2011) 849-875. [2] P. Appendini, J.H. Hotchkiss, Review of antimicrobial food packaging, Innov. Food Sci. Emerg. Technol. 3 (2002) 113-126. [3] M. Uz, S.A. Altmkaya, Development of mono and multilayer antimicrobial food packaging materials for controlled release of potassium sorbate, LWT-Food Sci. Technol. 44 (2011) 2302-2309. [4] P. Suppakul, J. Miltz, K Sonneveld, S.W. Bigger, Active packaging technologies with an emphasis on antimicrobial packaging and its application, J. Food Sci. 68 (2003) 408-420. [5] A. Figoli, E. Mascheroni, S. Limbo, E. Drioli, Membrane for food packaging, chapter 10, in: V. Peinemann, S. Pereira Nunes, L. Giorno (Eds.), Membrane Technology: Volume 3: Membranes for Food Applications, Wiley-VCH Verlag GmbH & Co., Germany, 2010. [6] L Vermeiren, F. Devlieghere, M. van Beest, N. de Kruif, J. Debevere, Development of the active packaging of foods, Trends Food Sci. Technol. 19 (1999) 77-86. (C) 2016 Elsevier Ltd. All rights reserved.