Taints, food-packaging

Consideration of these parameters is important when tracking the source of taints and interpreting the relationship between analytical chemistry and sensory impact of the food-package interaction. 

Styrene monomer concentration in foods packaged in 31 different PS-containing food packages and contact materials averaged 224 mg/kg with two products having concentrations between 800 and 1500 mg/kg, well above the sensory threshold limits (Baner, 2000). Strict specifications for styrene monomers as well as for residual solvents, toluene, and odor and taint transfer for supplier materials should be set (Huber et al., 2002). 

Placing printed premiums (coupons) within a food package is common but these materials also may be sources of taints. Premiums intended for packaged dry mix beverages were tested for their contribution of... 

The objective of this chapter is to give an overview of the processes and problems related to prints on food packages, dealing primarily with the components of inks and their possible migration into the foodstuff. Sensory (odour and taint) aspects and testing will also be covered and statutory requirements will be discussed. 

Low-odour inks for food packaging are based on odour and taint-free substances, for example, aromatic free solvents and maleic resins. So called semi-drying oils are also used. These are slow to oxidise and therefore do not develop malodorous aldehydes as they dry. However, some smell may be noticed after a long period of time as oxidation proceeds. Other solvents, such as tung oil, develop quite some odour during drying but if properly... 

TICE P A and OFFEN c P (1994), Odors and taints from paperboard food packaging , Tappi J, 77(12), 149-154. 

Active food packaging is a film or coating that is directly or indirectly in contact with any food surfaces to increase the shelf life or improve the quality of the packaged food. The big classifications fall under either oxygen-scavenging or antimicrobial but other upcoming types such as ethylene-scavenging, moisture absorbers, taint removers, and color and flavor enhancers have also been identified. 

Analytical measurements and investigations are therefore carried out to detect and measure volatile odorous substances in food packaging either for quality control purposes or when odor and taint problems arise. The technique of choice is GC-MS. 

Figure 5 Chromatogram of volatile substances from a carton-board food packaging printed with a LIV-cured ink. Benzophenone, the printing ink component responsible for tainting of packaged food, is represented by the peak at 15.7 min.

Solvent residues from printing and adhesives have the potential to cause food tainting. Typical solvents used in printing with characteristic, easily detectable odors are aliphatic esters, such as ethyl acetate, isopropyl acetate, and w-propyl acetate, the alcohols isopropyl alcohol and w-propyl alcohol and hydrocarbon mixtures, particularly aromatics. Regular tests are carried out by printers of food packaging to ensure that the concentrations of solvent residues are maintained below the odor and tainting threshold levels. The most widely used analytical technique to measure the levels of solvent residues is GC head-space analysis. Portions of the packaging are placed in sealed vials or other suitable containers and heated... 

Steam-solvent distillation using diethyl ether has been used to remove and analyse for odour and taint from additives in food packaging films. Another technique that has been used is vacuum/thermal extraction. This procedure has been applied to polyamides and fluorocarbon polymers. The procedure is used for the direct isolation or release of volatile components from a polymeric matrix and may involve the combined use of vacuum and heat, as for example in the mass spectrometer direct insertion probe or during dry vacuum distillation. Alternatively, the volatiles may be swept from the heated sample by a flow of inert gas for concentration by freeze trapping and/or collection on to a solid adsorbent prior to thermal or solvent desorption for GC or mass spectrometric (MS) examination. 

Food packaging materials are frequent contributors to taints found in food products [31]. Virtually the only food packaging material that will not potentially contribute a taint to foods is glass. Since food is not sold in glass ampoules (i.e., sealed entirely... 

Food and drink containers extruded or moulded from polyethylene may occasionally possess unpleasant odours which are likely to taint the packaged product and are unacceptable to the consumer. In one such case it was found that by heating a sample of an odour-producing polyethylene for 15 min at 200 C under helium the chromatogram of the liberated volatiles contained certain peaks which were absent from the corresponding chromatogram from a polyethylene which produced non-odourous food containers. The temperature of200°C was chosen to simulate the extrusion temperature. 

In the early years of their use, plastics were regarded as essentially unreactive materials and there was a widespread ignorance of the chemistry of the materials and of the variety of compounds used in their manufacture. A decade or so ago, reports of adverse reactions arising from the use of plastics in a number of applications began to appear. These included problems of colour modification, flavour and odour taint of packaged food, and also unforeseen biological effects due to the use of plastics in the construction of medical appliances. Health problems associated with vinyl chloride processing led to the... 

---