33A-11 |
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E. A. CLUBBS1, T. H. Shellhammer2, and Y. Vodovotz1. (1) Dept. of Food Science & Technology, Ohio State Univ., 2015 Fyffe Ct., 110 Parker Food Science Bldg., Columbus, OH 43210-1007, (2) Dept. of Food Science & Technology, Oregon State Univ., 232-A Wiegand Hall, Corvallis, OR 97331-6602 Traditional corn tortillas are produced from dehydrated masa and water and have a very short shelf-life of 1-3 days due to increased firmness in the product. Commercial corn tortillas use carboxymethylcellulose (CMC) to delay staling; however this gum is not only expensive, but also imparts off-flavors to the product. Alternative additives such as glycerol and salt may prove to be a viable option. The objective of this study was to investigate the physico-chemical changes due to the addition of glycerol/salt and CMC to corn tortillas during storage conditions. Tortillas were prepared using a 60:40 water/masa ratio, with and without 4% glycerol (db) 1% salt (db) or 0.5% CMC (w/w) and were vacuum packaged individually in high-barrier flexible pouches. Molecular and macroscopic changes were measured using differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and Instron mechanical analysis during two weeks of storage at 25°C. During storage all samples exhibited an increase in amylopectin crystallization, with glycerol and salt tortillas resulting in the greatest increase. For all tortillas, the “freezable” water (FW) content decreased over the first 3-5 days of storage with no further change while moisture content remained constant. Glycerol and salt tortillas exhibited a more homogenous composition throughout storage characterized by the steepness of the slope of the main transition in DMA. However, CMC tortillas were significantly less stiff initially than the control and glycerol and salt tortillas yet became stiffer at a greater rate over the second week of storage. To maintain the pliability during storage, glycerol and salt may prove a viable alternative to CMC if used in combination with other antistaling agents.
Session 33A, Carbohydrate: General
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