Performance of Nonmigratory Iron Chelating Active Packaging Materials in Viscous Model Food Systems

Abstract

Many packaged food products undergo quality deterioration due to iron promoted oxidative reactions. Recently, we have developed a nonmigratory iron chelating active packaging material that represents a novel approach to inhibit oxidation of foods while addressing consumer demands for "cleanˮ labels. A challenge to the field of nonmigratory active packaging is ensuring that surface-immobilized active agents retain activity in a true food system despite diffusional limitations. Yet, the relationship between food viscosity and nonmigratory active packaging activity retention has never been characterized. The objective of this study was to investigate the influence of food viscosity on iron chelation by a nonmigratory iron chelating active packaging material. Methyl cellulose was added to aqueous buffered iron solutions to yield model systems with viscosities ranging from ∼1 to ∼10(5) mPa·s, representing viscosities ranging from beverage to mayonnaise. Iron chelation was quantified by material-bound iron content using colorimetry and inductively coupled plasma-optical emission spectrometry (ICP-OES). Maximum iron chelation was reached in solutions up to viscosity ∼10(2) mPa·s. In more viscous solutions (up to ∼10(4) mPa·s), there was a significant decrease in iron chelating capacity (P < 0.05). However, materials still retained at least 76% iron chelating capacity. Additionally, the influence of different food hydrocolloids on the performance of nonmigratory iron chelating active packaging was characterized. Methyl cellulose and carrageenan did not compete with the material for specific iron chelation (P > 0.05). Materials retained 32% to 45% chelating capacity when in contact with competitively chelating hydrocolloids guar gum, locust bean gum, and xanthan gum. This work demonstrates the potential application of nonmigratory iron chelating active packaging in liquid and semi-liquid foods to allow for the removal of synthetic chelators, while maintaining food quality.

Synthesis of Iminodiacetate Functionalized Polypropylene Films and Their Efficacy as Antioxidant Active-Packaging Materials

“…Such nonmigratory metal-chelating active packaging materials can enable the removal of synthetic chelators (e.g., EDTA) in liquid to semisolid food systems. Indeed, we have previously demonstrated that such solid support-bound chelating materials are effective in both chelating transition metals and inhibiting transition-metal-promotive oxidative degradation reactions in foods of viscosities up to a semisolid gel (e.g., mayonnaise) . Alternative strategies would need to be explored for dry- and solid-food systems.…”

“…Indeed, we have previously demonstrated that such solid support-bound chelating materials are effective in both chelating transition metals and inhibiting transition-metal-promotive oxidative degradation reactions in foods of viscosities up to a semisolid gel (e.g., mayonnaise). 51 Alternative strategies would need to be explored for dry-and solid-food systems. Future studies on the applications of these materials in true food systems, with corresponding sensory analyses, are necessary to further demonstrate their performance prior to commercial adoption.…”

Retaining Oxidative Stability of Emulsified Foods by Novel Nonmigratory Polyphenol Coated Active Packaging

“…Iron chelating capacity of each film was quantified by ICP-MS analysis (PerkinElmer Elan 9000, Waltham, MA). Film was prepared for ICP-MS analysis by microwave acid digestion as previously described. ,, In order to evaluate the coated material performance stability and assess iron binding affinity, additional iron chelating studies were conducted at different pH values (pH 3, 3.5, 4, 4.5) and in the presence of competitive chelators at pH 4.0 at the following chelation ratios: 2:1 citric acid/Fe, 2:1 NTA/Fe, 1:1 EDTA/Fe, and 1:1 DFO/Fe …”

Reactive Extrusion of Nonmigratory Antioxidant Poly(lactic acid) Packaging

“…Numerous active packaging technologies have been reported, including antioxidant, ,− antimicrobial, water absorbing, and gas scavenging . In one class of antioxidant active packaging technologies, metal-chelating groups were introduced on the surface of polymer films to limit oxidation by binding pro-oxidant transition metals naturally found in foods and beverages. , Among metal-chelating groups, hydroxyamic acid − and iminodiacetic acid , showed great promise due to their efficacy at preventing oxidation in food matrices, structural similarity to industrially relevant metal chelators (desferroxamine and ethylenediaminetetraacetic acid (EDTA)), and high stability constants with pro-oxidant metals such as iron and copper . We have previously reported on the covalent immobilization of metal chelators onto petroleum-derived polymers in the preparation of nonmigratory antioxidant active packaging using wet chemistry techniques.…”