Water-Holding Capacity and Textural Acceptability of Precooked, Frozen, Whole-Egg Omelets

Precooked, frozen omelets were analyzed for moisture loss, expressible moisture, shear-force, and sensory evaluation to determine water-holding capacity and- textural acceptability. Addition of 0.1% xanthan gum, application of moist heat in cooking, and cryogenic freezing with liquid carbon dioxide or nitrogen minimized moisture loss and shear force. Sodium. carboxymethylcellulose (CMC), pre-gelatinized tapioca starch and sodium tripolyphosphate additives performed satisfactorily, but omelets containing xanthan gum were consistently rated highest in sensory evaluation of several treatments, including fresh and untreated control omelets. Steaming omelets for five minutes combined with cryogenic freezing produced a desirable- omelet, requiring no additives. Steamed omelets were rated comparable to baked omelets in most sensory parameters.     

GEL CHARACTERISTICS OF β-LACTOGLOBULIN, WHEY PROTEIN CONCENTRATE AND WHEY PROTEIN ISOLATE

The gelation characteristics of β-lactoglobulin, whey protein isolate and whey protein concentrate at varying levels of protein (6–11%), sodium chloride (25–400 mM), calcium chloride (10–40 mM) and pH (4.0–8.0) were studied in a multifactorial design. Small scale deformation of the gels was measured by dynamic rheology to give the gel point (°C), complex consistency index (k*), complex power law factor (n*) and critical strain (γ_c). The gel point decreased and turbidity increased with increasing calcium level. The denaturation temperature measured by differential scanning calorimetry was measured at higher pH values. Large scale deformation at 20% and 70% compression was measured using an Instron Universal Testing machine. The true protein level had the largest effect on the stress required to produce 20% and 70% compression and on the consistency (k*) of the gels.