Antimicrobial active packaging

FIGURE 61.5 Schematic representation of antimicrobial active-packaging. Micro-organisms hydrolyze starch-based particles, causing release of the antimicrobial lysozyme, resulting in inhibition of microbial growth. (From De Jong, A.R. et al.. Food Addit. Contain., 22(10), 975, 2005.)... 

Gutierrez, L. Sanchez, C. Batlle, R. Nerin, C. New antimicrobial active package for bakery products. Trend Food Sci. Tech. 2009, 20 (2), 92-99. 

Persico, R Ambrogi, V. Carfagna, C. Cerruti, R Ferrocino, I. Mauriello, G. Nanocomposite polymer films containing carvacrol for antimicrobial active packaging. Polymer Engineering Science, 2009, 49(7), 1447-1455. 

This aromatic alcohol has been an effective preservative and still is used in several ophthalmic products. Over the years it has proved to be a relatively safe preservative for ophthalmic products [138] and has produced minimal effects in various tests [99,136,139]. In addition to its relatively slower rate of activity, it imposes a number of limitations on the formulation and packaging. It possesses adequate stability when stored at room temperature in an acidic solution, usually about pH 5 or below. If autoclaved for 20-30 minutes at a pH of 5, it will decompose about 30%. The hydrolytic decomposition of chlorobutanol produces hydrochloric acid (HC1), resulting in a decreasing pH as a function of time. As a result, the hydrolysis rate also decreases. Chlorobutanol is generally used at a concentration of 0.5%. Its maximum water solubility is only about 0.7% at room temperature, which may be lowered by active or excipients, and is slow to dissolve. Heat can be used to increase dissolution rate but will also cause some decomposition and loss from sublimation. Concentrations as low as 0.125% have shown antimicrobial activity under the proper conditions. 

Ayala-Zavala JF, del-Toro-Sanchez L, Alvarez-Parrilla E, Soto-Valdez H, Martin-Belloso O, Ruiz-Cruz S and Gonzalez-Aguilar GA. 2008b. Natural antimicrobial agents incorporated in active packaging to preserve the quality of fresh fruits and vegetables. Stewart Postharvest Rev 4 1—9. 

Vartiainen J, Ratto M, Paulussen S (2005) Antimicrobial activity of glucose oxidase-immobilized plasma-activated polypropylene films. Packag Technol Sci 18 243-251... 

Antimicrobial activity benzyl alcohol is bacteriostatic and is used as an antimicrobial preservative against Gram-positive bacteria, molds, fungi, and yeasts, although it possesses only modest bactericidal properties. Optimum activity occurs at pH below 5 little activity is shown above pH 8. Antimicrobial activity is reduced in the presence of nonionic surfactants, such as polysorbate 80. However, the reduction in activity is less than is the case with either hydroxybenzo-ate esters or quaternary ammonium compounds. The activity of benzyl alcohol may also be reduced by incompatibilities with some packaging materials, particularly polyethylene see Section 12. 

Examples of active package/food systems are individually wrapped ready-to-eat meat products, or deli products, where antimicrobial agents may be initially incorporated into the packaging materials and migrate into... 

In the design of antimicrobial films or packages various factors may be of importance. These include the chemical nature of films and lasting antimicrobial activity, storage temperature, mass transfer coefficients, and physical properties of packaging materials (Quintavalla and Vicini, 2002). 

The basic types of antinucrobial food packaging films are outlined and additives used in antimicrobial materials are discussed, with particular reference to potassium soibate, nisin, imazalil, allyl isothiocyanate and triclosan. The production of antimicrobial films by modification of the polymer chain itself is also mentioned and the natural antimicrobial activity of chitosan is considered. 17 refs. 

The current study provides a new type of edible, antimicrobial food packaging or wrapping films from food-grade natural fibers or hydrocolloid. Besides film casting, the films can also be produced by compression, extrusion blown methods. The inclusion of PEO hydrocolloid in natural fiber formulations makes films tougher and caused less permanent deformation when the films were subjected to an external force. Since the extrusion and compression were performed in mild conditions, nisin can be incorporated into films without diminishing its antimicrobial activity. 

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