Ann H. Barrett

Effects of Sucrose Ester, Dough Conditioner, and Storage Temperature on Long-Term Textural Stability of Shelf-Stable Bread

ABSTRACT The effectiveness of a dough conditioner containing an amylase enzyme, surfactants, and a reducing compound on preserving the textural stability of shelf-stable bread was compared with that of sucrose ester. Military-specification Meal, Ready-to-Eat bread was formulated to contain sucrose ester alone, the dough conditioner alone, both in combination, or neither additive. Samples were also stored at 4, 21, and 38°C for 12 weeks. Instrumental texture, as determined by uniaxial compression and mathematically fitted stress-strain relationships, and sensory texture, as determined by a trained texture panel, were assessed periodically between 0 and 12 weeks. Both sucrose ester and the dough conditioner yielded stored samples that were softer than the control; sucrose ester was slightly more effective than the dough conditioner in preserving instrumental texture, and the additive combination yielded the lowest firmness parameters. Thermal analysis results were consistent with mechanical and sensory eval...

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

ABSTRACT 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 ...

Textural stability of intermediate-moisture extrudates : Effects of formulation

ABSTRACT Effects of formulation on the textural stability of intermediate-moisture, flour-based, “jerky”-type extrudates were assessed. Potato-based extrudates containing various particulate-meat concentrations and different plasticizers (sucrose, fructose, glycerol, and glucose) were produced and subjected to accelerated storage for three weeks. The elastic modulus of the samples was measured before storage and then weekly. The relative fluidity and moisture mobility of the specimens were assessed by dynamic mechanical spectrometry (DMS), electron spin resonance (ESR), and nuclear magnetic resonance (NMR). Samples were also evaluated by fluorometry and X-ray diffraction to determine the extent of browning reaction and degree of molecular ordering, respectively. While elastic modulus increased appreciably during storage, firming was progressively reduced by entrained meat content and also by plasticizers, especially glycerol; plasticized and meat-containing samples had correspondingly lower tan δ peak tem...

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

ABSTRACT 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 fir...

The Inhibition of Maillard Browning by Different Concentrations of Rosmarinic Acid and Epigallocatechin‐3‐Gallate in Model, Bakery, and Fruit Systems

UNLABELLED Rosmarinic acid and Epigallocatechin gallate concentrations were studied as natural inhibitors of Maillard browning in glucose/glycine model systems, and in bakery rolls and applesauce. The concentrations of the inhibitors were varied to determine the highest level of inhibition without a pro-oxidant/browning effect. UV absorbance and gas chromatography/mass spec (GC/MS) with solid phase microextraction (SPME) sampling was used to study browning in the model systems. Hunter L*, a*, b* was used to analyze the color change results of the inhibitors on applesauce and bakery rolls. It was determined that a 1.0% solution of either antioxidant in the glucose/glycine system produced the greatest inhibition and a synergistic effect was not apparent when the two were combined. Inhibition of browning and a lack of synergy between the antioxidants were also determined in food systems consisting of applesauce and bakery rolls. GC/MS analysis of the model system revealed a high level of pyrazine formation in no-inhibitor control samples and the absence of pyrazines in inhibitor-containing samples. PRACTICAL APPLICATION Natural browning inhibitors, that is Rosmarinic acid and Epigallocatechin gallate, can be added to food items to inhibit browning over a prolonged period of storage in order to increase product shelf stability. The concentrations of the inhibitors require optimization since a pro-oxidant effect and increased browning will occur at high levels.