Degradable Wheat Gluten Films: Preparation, Properties and Applications

Degradable films from spray-dried (SD) and flash-dried (FD) wheat gluten prepared at various pHs, salt levels, temperatures, and shearing times were compared. Differences were observed in properties of the films related to processing conditions. Films prepared from SD wheat gluten were thicker, and had higher tensile strengths and Young's moduli. SD wheat gluten solutions applied as coating material resulted in Grade A-quality shell eggs maintaining quality for 30 days at room temperature. Additionally, SD wheat gluten coating increased the water stability of starch-based packaging.     

Mechanical and Barrier Properties of Rice Bran Films

Biodegradable films were prepared from rice bran, and their water vapor and oxygen permeabilities, mechanical properties and solubilities were studied. No differences in apparent water vapor permeability (WVP_app) were observed between rice bran films cast at pH 9.5 (RBfilm 9.5) and those cast at pH 3.0 (RBfilm 3.0). Rice bran films had higher WVP_app and oxygen permeability when compared to a polyvinylidene chloride film. RBfilm 3.0 had lower oxygen permeability compared to RBfilm 9.5. Puncture strength, tensile strength, breaking factor, and protein solubility of RBfilm 9.5 were higher than those of RBfilm 3.0. A positive correlation (r = 0.91) was observed between puncture strength and tensile strength of films.     

Protein Concentrates from Unstabilized and Stabilized Rice Bran: Preparation and Properties

Protein concentrates were prepared from commercially available unstabilized and heat stabilized rice bran by alkaline extraction and isoelectric precipitation. Stabilized rice bran had lower protein extractability at all particle sizes (75μ to 150μ). Both unstabilized rice bran protein concentrate (URBPC) and stabilized rice bran protein concentrate (SRBPC) showed maximum nitrogen solubility at pH 8.0. URBPC (71.5% protein) and SRBPC (50.9% protein) showed differences in amino acid contents. SDS-PAGE of protein concentrates revealed several common components and absence of certain components from SRBPC. Protein denaturation due to commercial heat stabilization impaired extractability of proteins and influenced its quality.     

Microstructure of Frankfurters Extended with Wheat Germ Proteins

Transmission electron microscopy was utilized to study the microsctructure of frankfurters extended with wheat germ protein flour (WGPF) at 3.5, 5.0, and 7.0%. Samples with 3.5% WGPF showed a denser matrix than the control. They also had a uniform interfacial protein film (IPF) with a slight increase in average thickness. At WGPF >3.5%, no further effects on IPF were observed. At 7.0% WGPF, an increase in added water, and the resultant dilution of meat and fat components, resulted in fewer fat globules, some with incomplete IPFs. Proteins in the WGPF contributed to IPF formation up to a specific level. Nonprotein components also were important in batter stability by absorbing water.     

Calcium Fortification of Rice: Distribution and Retention

A method of calcium fortification of milled rice was developed and tests conducted to investigate calcium distribution and retention. Milled rice (Karen variety) was soaked in 3.0% calcium lactate solution (CLS)(rice: CLS, 1.0:0.75 w/v) for 3 hr at room temperature followed by steaming 10 min at 0.68 atm, and drying to 10–11% moisture. Washing fortified rice resulted in calcium losses of ～5%. Calcium fortified rice flour samples after dialysis, retained ～60% of original calcium. Fortification process met U.S. standards for calcium-fortified rice (110–220 mg/100g rice) and resulted in minimal washing losses.     

Functionality of Wheat Germ Protein in Comminuted Meat Products as Compared with Corn Germ and Soy Proteins

Wheat germ protein flour (WGPF), corn germ protein flour (CGPF), and soy flour (SF) were used as additives at a level of 3.5% in comminuted meat products (CMP). Frankfurters with protein additives showed increased water-holding capacity and batter stability and decreased cooking loss. Improved viscosity and adhesiveness were observed with protein additives when the level of added water was constant. Protein additives also influenced textural and sensory properties of frankfurters. WGPF at a level of 3.5% was found similar to effects of SF and CGPF. WGPF is a potential nonmeat protein additive that can be utilized as an extender in CMP such as frankfurters and bologna.     

Natural Antioxidant Extract from Fenugreek (Trigonella foenumgraecum) for Ground Beef Patties

Ground beef patties (75% lean) containing synthetic antioxidants, or Fenugreek (Trigonella foenumgraecum) extracts were cooked to internal temperature 70°C, and evaluated for storage stability at 4°C. Thiobarbituric acid values of raw or cooked samples containing fenugreek extracts were lower than controls (P<0.05). Fenugreek extracts delayed the induction period of oxidative rancidity. No differences were observed in psychrotrophic bacterial counts, and samples containing fenugreek extracts had lower Hunterlab “a” and higher “b” values. Samples with Fenugreek extracts had better oxidative stability and Fenugreek may be a promising natural antioxidant source.     

FRANKFURTERS EXTENDED WITH WHEAT GERM PROTEIN: SENSORY PROPERTIES AND CONSUMER RESPONSE1

In this study, 103 consumers evaluated the sensory acceptance of frankfurters extended with wheat germ protein flour (WGPF). Consumers as a whole did not perceive any differences in the attributes of appearance, flavor, texture, and overall acceptance. However, samples with WGPF were scored lower for intensities of hot dog flavor and spiciness. Perception of intensities of attributes varied depending on age, frequency of consumption, and whether the consumer was male or female. WGPF did not influence the overall acceptance of the product. A trained panel found a difference in smoky flavor due to treatment and a weak difference in smoky aroma and flavor due to storage. Trends suggested an effect due to increasing levels of WGPF on aroma and flavor of frankfurters.     

PHYSICOCHEMICAL PROPERTIES OF THREE RICE VARIETIES

Physicochemical properties of three rice varieties were studied. Textural properties of gels from La Grue, Bengal, and S201, were investigated using the Universal Texture Analyzer, and pasting characteristics by Brabender Visco/amylography. Gels from La Grue (long grain) had higher fracturability, hardness, amylographic consistency, and setback viscosity (P<0.05). Gels from S201, a short grain variety, were harder and had higher fracturability values than those from Bengal, a medium grain variety. Analysis of texture profiles of rice gels could be an alternative to Brabender viscoamylographs for differentiating among rice varieties. Tests on in-vitro starch digestibility showed that La Grue had lower maltose released than S201 or Bengal during the first 15 and 45 min of hydrolysis with human salivary α-amylase.