27-3 |
Sorption behavior of an aliphatic series of aldehydes in the presence of polyethylene terephthalate blends containing aldehyde scavenging agents |
J. E. Marcy1, E. C. SULOFF1, B. A. Blakistone2, S. E. Duncan1, T. E. Long3, and S. F. O'Keefe1. (1) Dept. of Food Science & Technology, Virginia Polytechnic Institute & State Univ., 118 FST Bldg., Mail Code 0418, Blacksburg, VA 24061-0418, (2) Food Technologies & PET Analytical Lab., Graham Packaging Co., L.P., Graham Global Technology Center, 3640 Sandhurst Dr., Ste. F, York, PA 17402-7937, (3) Dept. of Chemistry, Virginia Polytechnic Institute & State Univ., 3107 Hahn Hall, Mail Code 0212, Blacksburg, VA 24061-0212 The quality of many beverages and food products is compromised by the presence of low molecular weight aldehydes. Aldehydes are commonly formed during storage by the oxidation of lipids or are introduced as migrants from polymeric packaging material. Our objective was to evaluate the effectiveness of three aldehyde scavenging agents, blended into poly(ethylene terephthalate) (PET) films, in removing an aliphatic series of aldehydes from an acidified aqueous model solution (pH 3.6) during storage. Aldehyde concentration in solution was determined by an improved high performance liquid chromatography method involving the formation of aldehyde-hydrazine complexes by 2,4-dinitrophenylhydrazine. Storage of 25 mM mixtures of acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and caproaldehyde in contact with PET films blended with 5% poly(m-xylylene adipamide) (nylon MXD6), D-sorbitol, or a-cyclodextrin reduced the concentration of each aldehyde in solution by 21 to 90% after 14 days of exposure. D-sorbitol and a-cyclodextrin aldehyde scavenging PET films were the most effective treatments for the reduction of aldehydes from solution showing similar average reductions for the five aldehyde species of 11.4 and 13.8 mM, respectively. PET films blended with nylon MXD6 were less effective in removing aldehydes from solution showing an average reduction of 8.4 mM for the five aldehyde species. However, nylon MXD6 proved to be the most efficient aldehyde scavenging agent tested. D-sorbitol and a-cyclodextrin blends include 45 and 18 times more aldehyde scavenging sites then nylon MXD6 blends, but only showed 26 and 39% improvements in aldehyde scavenging ability when compared to nylon MXD6 blends. Aldehyde scavenging films demonstrated selective scalping preferring smaller molecular weight aldehydes, such as acetaldehyde, propionaldehyde, and butyraldehyde, more than larger aldehydes, valeraldehyde and caproaldehyde. Partition coefficients for smaller aldehydes were 3 to 6 times greater for aldehyde scavenging films then control film. The use of aldehyde scavenging agents in food packaging materials may protect the flavor profile and extend the shelf-life of foods and beverages throughout storage by the selective removal of deleterious aldehyde species.
Session 27, Food Packaging: General
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