Smart Packaging Adds a Dimension to Safety

As consumers require more minimally processed foods, the interest in “smart” packaging increases. At this year’s IFT Annual Meeting, several papers looked at the various aspects of packaging related to food safety. At the same time, patents are beginning to proliferate on the subject of “smart” packages,

Such packages may exhibit several varieties of intelligence. Antimicrobial materials can be introduced into packaging polymers or onto the surface of containers; packages may be developed specifically for treatment to reduce bacterial content; or combinations of those methods can be used. Another kind of “smart” may be the development of packages that withstand various kinds of processing techniques without damage, permitting the enclosed product to be safer over an extended shelf life.

Research into the effectiveness of propyl paraben and its manner of use was reported by D. Chung and K.L. Yam of Rutgers University. They indicated that propyl paraben can be dispersed in polymer emulsions and applied to clay-coated papers for use in food packaging. Antimicrobial activity was measured by agar diffusion and cell culture tests. Diffusion studies suggested that release of the antimicrobial varies with the composition of the food wrapped in the coated paper.

M.A. Khadre and A.F. Yousef of Ohio State University found that using ozone as a means of disinfecting packaging was effective in decreasing bacteria, specifically Pseudomonas fluorescence, which was used as a model system, by up to 5 logs, and from formed biofilms by up to 3 logs. Usage rate was 5–18 ppm of ozone in water.

Use of pulsed light as a secondary treatment to sterilize packages and their contents is disclosed in U.S. patent 5,925,885, assigned to PurePulse Technologies, Inc. This method of sterilization permits the use of packages that do not include polyvinyl chloride, such as polyethylene or thin polypropylene containers which cannot withstand the temperatures presented by autoclaving. (PVC’s resistance to heat has made it the preferred package for products such as parenteral and enteral prefilled products, despite some environmental problems.)

The use of antimicrobial agents, including phytochemicals and chemical releasers, in polymers used for forming packaging is described in U.S. patent 5,906,825, assigned to Magellan Companies Inc. The polymers discussed include silicones, polystyrenes, polyacrylates, polyurethanes, polyalkylenes, polyolefins, polyvinyls, synthetic rubbers, latex, Npropylsilicates and mixtures. Biocides discussed include capsicum, grapefruit seed extract, lemongrass oil, tea tree oil, citric acid, and mixtures of these materials. A chemical release agent can be added to control the migration and release of the antimicrobial; some release agents include vitamin E and citric acid.

An older technology is described in U.S. patent 5,573,797, which discusses the addition of Streptococcus or Pediococcus-derived bacteriocin or a synthetic equivalent combined with a chelating agent to a food; it can also be used without the chelating agent in a packaging film. The patent was assigned to Viskase Corp. Claims describe the package as a film, such as a polymeric film or a regenerated cellulosic film, containing a heat-resistant, Pediococcus-derived bacteriocin in a synergistic combination with a chelating agent to inhibit or kill Listeria monocytogenes on contact with a food.

As consumers want foods to be processed less strenuously than in the past, and packaging that permits better processing, provides antibacterial activity of its own, or permits a process that enhances safety without changing texture and flavor will bring a positive response.

PATENTS
Some patents of interest to those selecting packaging are listed below. Patents can be downloaded from the Internet at www.uspto.gov at no cost. Click on patent search, and type in the patent number.

Water insoluble film. U.S. patent 5,962,053, filed 2/17/98, issued 10/5/99 to F.M. Merritt II, assigned to Viskase Corp. Describes an edible, water-insoluble film made from a polysaccharide and protein, particularly konjac flour, agar, and gelatin. The film is formed by deacetylating the konjac flour to insolubilize it, forming an insoluble film.

System and method for filling and sealing containers in controlled environments. U.S. patent 5,961,000, filed 11/4/96, issued 10/5/99 to J.J. Sanfilippo et al. Describes an open architecture system for filling and sealing containers in controlled environments. The system provides easy access to containers being processed, and minimizes startup times and waste. Containers are processed by gas distributors (which may include gassing rails) that are provided in segments and individually movable between operating and service positions. Exhaust plenums are described for improving function of the gas distributors when processing containers.

Polymer packaging. U.S. patent 5,962,051, filed 10/29/96, issued 10/5/99 to P. Noble et al., assigned to Pernod Richard. Describes a long-life polymer package for a fruit-based and/or vegetable-based drink. The packaging includes a monolayer formed of a methyl acrylate acrylonitrile/butadiene terpolymer. The invention also discloses a process intended to limit the degradation of fruit-based and/or vegetable-based drinks contained in the polymer package.

Products & Literature
A CORK DESIGNED BY WINEMAKERS is made from Dow Plastics Affinity polyolefin plastomers and provides a state-of-the-art closure that protects the wine and doesn’t cause the suave opener of the bottle to look like a dolt when the cork crumbles. That’s because the cork never crumbles. Instead, the extruded plastic closure slides from the neck of the bottle as a clean cylinder. The “corks” offer the same oxygen transmission rates as natural wood corks and meet FDA requirements for direct food contact. The cork, called Neocork, is made by Neocork Technologies, Inc. from foamed Affinity polyolefin plastomers with an outer layer of elastomeric materials, using a process described as profile extrusion, in which the foamed resins are extruded as a continuous part, then cut to the proper length. The smooth outer surface is printed or branded with company names or logos to identify the product. Neocork Technologies was founded in 1996 with the support of Beringer Wine Estates, Clos de Bois, Kendall Jackson Vineyards, Ronert Mondavi, and Tirner Road Vintners. For more information about the “cork,” write to Neocork Technologies, 110-A Mezzatta Ct., American Canyon, CA 94589 (phone 707-642-6800, e-mail [email protected]) —or circle 378. For more information about Affinity resins, write to The Dow Chemical Co., Customer Information Group, Attention E#1961, P.O. Box 1206, Midland MI 48641-1206 (phone 800-441-4369)—or circle 379.

NEW PRODUCT FEEDER matches packaging speeds up to 600/min. The horizontal form-fill-seal wrapper is a fast, flexible unit that features a dual self-centering film spindle to save film-threading time. The unit is controlled by a touch-screen control, and features a 30-product-size memory for fast changeovers. For more information, contact Formost Packaging Machines, Inc., 19211-144th Ave., N.E., Woodinville, WA 98072 (phone 4256-483-9090, fax 425-586-5656) —or circle 380.

NONDESTRUCTIVE UNIT tests UHT milk products, particularly 125- to 1,000-cc UHT brik-type cartons supplied by Tetra-Pak and Combibloc, by checking the hydrodynamic behavior of the contents, at speeds approaching 1,000/hr. Because testing is so rapid, a higher proportion of cartons can be tested. The ElecTester MK IV detects slight changes by oscillating the package and measuring the reduction in amplitude. For information, write to Eibis International, P.O. Box 308, Ramsgate, CT12 5DG, England (phone +44 (0) 1843 821358, fax +44 (0) 1843 821328)—or circle 381.

by FRAN KATZ
Editor