Chitosan‐coated paper: Effects of nisin and different acids on the antimicrobial activity
ABSTRACT Chitosan coatings prominently improved both the gloss and oxygen barrier properties of paper. The gloss value in the machine direction was increased as a function of added chitosan. An oxygen-permeability value of 1.1 cm3/m2 d was obtained when 6.9 g/m2 chitosan was applied to 80 g/m2 copy paper. In addition, the effects on the mechanical properties were positive, but not significant. The water-vapor permeability of the paper increased as a result of the chitosan coating. Chitosan dissolved in 1.6, 3.2, and 6.4% lactic acid showed antimicrobial activity against Bacillus subtilis, whereas acetic and propionic acids (1.6, 3.2, and 6.4%) did not produce any notable activity. Nisin (0.08 g/L) did not enhance the antimicrobial activity of coatings prepared from chitosan dissolved in different acids. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 986–993, 2004
SourceAvailable from: forumware.wu-wien.ac.at[Show abstract] [Hide abstract]
ABSTRACT: There are many studies in which was shown that vacuum or modifed atmosphere packaging materials, made from polyethylene-or other plastic based materials, have been found to improve the stability and safety of raw or further processed foods. A great variety of bio-based materials have been shown to prevent moisture loss, drip, reduce lipid oxidation, improve some of their sensor properties (colour, taste and smell) and gave microbial stability of foods. Nowadays, еdible films and coatings are applied on many products to control moisture transfer, gas exchange or oxidation processes. The major advantage of using edible films and coatings is that several active ingredients can be incorporated into the polymer matrix and consumed with the food, thus enhancing safety or even nutritional and sensory attributes. This article discusses the use of edible films and coatings as carriers of functional ingredients on foods, including the recent advances in the incorporation of antimicrobials, antibrownings, texture enhancers and nutraceuticals to improve storage, quality and functionality of foods.
[Show abstract] [Hide abstract]
ABSTRACT: Papers coated with caseinate and caseinate/chitosan bilayer films were developed. Caseinate, chitosan and caseinate/chitosan films were preliminary characterized by FTIR spectroscopy and thermal stability analyses. The effects of coating weight, caseinate concentration (7%, 10%, and 12%, w/w), and coating application methods (single layer and bilayer) on the physical and mechanical properties of coated papers were studied. Increasing the concentration of caseinate led to a decrease in water vapor permeability (WVP) of the resulting coated paper sheets. Chitosan significantly (p<0.05) increased the elongation at break (%E) of coated paper. However, the application of chitosan as a second layer on wet or dry caseinate films did not significantly affect (p>0.05) the tensile strength (TS) of coated paper. The greatest reduction in paper WVP is achieved by addition of a chitosan layer to the dried preformed caseinate-coated paper.01/2014; 99:508-16. DOI:10.1016/j.carbpol.2013.08.086
[Show abstract] [Hide abstract]
ABSTRACT: The industry and consumers are focusing more and more on the development of biodegradable and lightweight food-packaging materials, which could better preserve the quality of the food and improve its shelf-life. In an attempt to meet these requirements, this study presents a novel bio-substrate able to contain active bio-molecules for future food-packaging applications. Based on a paperboard substrate, the development of an antibacterial bio-packaging material is, therein, achieved using a chlorhexidine digluconate (CHX) solution as a model of an antibacterial molecule, mixed with microfibrillated cellulose (MFC) and used as coating onto paperboard samples. AFM and FE-SEM analyses were performed to underline the nanoporous MFC network able to trap and to progressively release the CHX molecules. The release study of CHX was conducted in an aqueous medium and showed a lower proportion (20 %) of CHX released when using MFC. This led to the constant release of low amounts of CHX over 40 h. Antibacterial tests were carried out to assess the preservation of the antibacterial activity of the samples after the release studies. Samples remained active against Bacillus subtilis, with better results being obtained when MFC was used. The preservation of the quality of a model food was finally evaluated paving the way for future promising applications in the food packaging industry.Journal of Food Science and Technology -Mysore- 01/2015; DOI:10.1007/s13197-014-1675-1 · 2.02 Impact Factor