DOI: 10.1094/CC-82-0152 |  VIEW ARTICLE

Effect of Different Enzymes on the Textural Stability of Shelf-Stable Bread.

Ann H. Barrett (1), Gina Marando (1), Henry Leung (2), and Gönül Kaletunç (3,4). (1) Performance Enhancement and Food Safety Team, Combat Feeding Directorate, U.S. Army Natick Soldier Center, Natick MA 01760-5018. (2) Frito-Lay, Inc., Plano, TX. (3) The Ohio State University, Department of Food, Agricultural, and Biological Engineering, Columbus, OH. (4) Corresponding author. Phone: 614-292-0419. Fax: 614-292-9448. Email: <kaletunc.1@osu.edu> Cereal Chem. 82(2):152-157. Accepted October 11, 2004. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. American Association of Cereal Chemists, Inc., 2005.

Three enzyme systems (2 amylase-based and 1 protease-based) were tested in shelf-stable bread to determine effectiveness in preserving texture during storage for eight weeks. Each enzyme was tested in formulations without glycerol or with 6% glycerol. Bread samples were analyzed to determine physical properties (crumb density, crust-to-crumb ratio, rate of moisture distribution from crumb to crust), mechanical properties (modulus, and a parameter [C1] describing resistance to high levels of deformation obtained by fitting stress-strain data to a three-parameter function), and thermal properties (thermal stability and enthalpy of transitions) as a function of storage time. Mechanical properties were further analyzed to predict asymptotic firmness. Bread firmness after storage as evaluated in terms of modulus and C1 were lower in all enzyme-added systems, the effect of protease being the most significant. Enzymes had less effect on glycerol-containing systems with no apparent trend. The breads had complex thermal behavior and exhibited multiple transitions. Both amylase preparations in the presence of glycerol reduced the amount of starch recrystallization.