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Textural Optimization of Shelf-Stable Bread: Effects of Glycerol Content and Dough-Forming Technique

¹U.S. Army Soldier and Biological Chemical Command, Natick Soldier Center, Natick, MA 01760-5018. ²Corresponding author. E-mail: abarrett@natick-emh2.army.mil. Phone: 508-233- 4516. Fax: 508-233-4054. ³Zymark Corp., Hopkinton, MA 01748. ⁴Geo Centers, Inc., Natick, MA 01760.

The effects of glycerol content and dough-forming method on the physical, textural, and sensory characteristics of shelf-stable bread were determined. Bread dough was produced with 0, 2, 4, and 6% nominal glycerol content, and formed into rolls by either dough-dividing or extrusion-forming methodologies. Baked products were evaluated by uniaxial compression and fitting of stress-strain data to a three-parameter mathematical model. A trained sensory panel quantified textural attributes using magnitude estimation methodology. Selected characteristics were also judged by an untrained consumer panel. Sensoryinstrumental relationships were determined. Products were tested instrumentally after different storage intervals to determine effects of glycerol level and dough-forming process on degree of firming. Results showed that extrusion-forming produced, on average, relatively more dense and less deformable products than did the dough-dividing method; extrusionformed samples also had greater sensory firmness and were less similar to an ideal sensory texture. However, high glycerol concentrations in extrusion-formed products gave sensory profiles that were substantially closer to the ideal. Sensory firmness and chewiness were closely correlated with parameters of power law functions that described compression behavior. Glycerol reduced ultimate firmness after storage.