Corn Germ Protein Flour Research Articles

Foaming Properties of Selected Plant and Animal Proteins

ABSTRACTThe foaming properties of proteins are important in predicting their fnnctionality in aerated foods. In model aqueous systems, foam expansion (FE) and foam stability (FS) of commercial plant proteins, wheat germ protein flour (WGPF), corn germ protein flour (CGPF), and soy flour (SF), were compared with those of nonfat dried milk (NFDM) and egg white powder (EWP) at 1, 2, 4, 6, and 8% using one‐ and two‐way analyses of variance. The effects of pH 4, 5, 6, 7, and 8 on FE and FS of WGPF were also measured. The highest overall FE and FS were obtained for EWP. Among plant proteins, FE and FS were maximum for CGPF and SF, respectively. FS was lowest for NFDM. Except for SF, FE and FS increased with increasing protein concentration. The FE and FS of WGPF were highest at pH 8, lowest at pH 7, and intermediate at pH 4–6.

Wheat Germ Protein Flour Solubility and Water Retention

ABSTRACTThe effects of pH and temperature on water retention (WR), protein solubility (PS), and total solubility (TS) of defatted wheat germ protein flour (WGPF) were studied in a model system. PS of WGPF was compared with those of corn germ protein flour (CGPF), soy flour (SF), nonfat dried milk (NFDM), and egg white powder (EWP) at 1–8%. WR increased with increase in pH from 4 to 8. Maximum WR occurred at 70°C, and slight variations were observed between 5 and 30°C. PS and TS increased with increases in pH and temperature. PS of proteins was in the order of NFDM > EWP > SF > CGPF=WGPF. The results showed the potential for usage of WGPF in comminuted meats, beef patties, breads, cakes, and cookies.

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

ABSTRACTWheat 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.

COMPARATIVE STUDY OF SHELF-LIFE OF FRANKFURTERS CONTAINING PLANT PROTEIN ADDITIVES

Soy flour (SF), soy concentrate (SC), soy isolate (SI) and corn germ protein flour (CGPF) were incorporated in frankfurters. The sensory analysis, chemical, and microbiological tests were conducted to investigate the effect of plant proteins on stability during vacuum-packaged storage. No significant difference in meaty aroma was found between all samples after 45 days storage. Atypical flavor and aroma of all samples, including the all-meat control increased (P < 0.05) after 45 days storage. A tendency was found of increase in atypical aroma and flavor with increase in total volatile nitrogen values and total psychrophiles during storage. Salty flavor increased with storage time in experimental samples, but juiciness decreased. Samples containing SF and SC had higher total volatile nitrogen than SI and CGPF containing samples at 2, 30 and 45 days of storage. No significant differences were found in TBA values between tested samples, except higher TBA values for SI containing samples. There was no significant difference among samples in total psychrophilic counts.

FUNCTIONALITY OF MILK PROTEINS AND CORN GERM PROTEIN FLOUR IN COMMINUTED MEAT PRODUCTS1

AbstractEffects of corn germ protein flour (CGPF), nonfat dry milk (NFDM), whey protein concentrate (WPC), and sodium caseinate (SC) on quality characteristics of comminuted meat products were studied. Water holding capacity (WHC) was lowest and cooking loss was highest for the control formulation, whereas formulations extended with CGPF and milk proteins were higher in WHC and lower in cooking losses. Shear force and firmness increased as extenders were added, except WPC. All frankfurters with extenders were firmer than the control, except those extended with WPC. Hue angle was highest for samples with CGPF, while no differences were found in hue angle between control and milk proteins containing samples, except samples with WPC. Frankfurters with CGPF and SC add had a stronger atypical aroma than the control. Meaty aroma score was higher for the control than for the other products, except those with WPC. Meaty flavor score was higher for the control than for all other products. The product with CGPF added had a stronger atypical flavor than the control. Frankfurters containing extenders were not as juicy as the all‐meat control.

Emulsifying Capacity and Emulsion Stability of Soy Proteins Compared with Corn Germ Protein Flour

ABSTRACTBoth emulsifying capacity (EC) and emulsion stability (ES) increased with increasing concentrations from 0.4% to 0.8% of soy flour (SF), soy concentrate (SC), soy isolate (SI) and corn germ protein flour (CGPF) when studied by response surface methodology. EC and ES increased as pH increased from 6 to 8 in all samples. Increasing incubation temperatures of protein solutions from 20–70°C or from 4–20°C did not affect EC or ES, respectively. SF had the highest EC, followd by SI, SC, and CGPF.

COMPARATIVE STUDY OF CORN GERM AND SOY PROTEINS UTILIZATION IN COMMINUTED MEAT PRODUCTS1

AbstractSoy flour (SF), soy concentrate (SC) and corn germ protein flour (CGPF) at 3.5%, or 2% of soy isolate (SI) were incorporated in the formulations of frankfurters. There was no significant differences in proximate composition of frankfurters containing SF, SC. SI, and CGPF. Frankfurters formulated with high plant protein flour had lower cholesterol, and higher protein content than the all‐meat control frankfurters. Control frankfurters had lower water holding capacity and higher cooking losses than those containing plant proteins. No significant differences (P &lt; 0.05) were found in textural and color characteristics. Atypical aroma and flavor profiles increased in frankfurters with SF nd CGPF extension.

Protein Solubility, Water Retention, and Fat Binding of Corn Germ Protein Flour Compared with Milk Proteins

ABSTRACTProtein solubility (PS), water retention (WR), and fat binding (FB) of corn germ protein flour (CGPF), nonfat dry milk (NFDM), whey protein concentrate (WPC), and sodium caseinate (SC) were comparatively studied using response surface methodology. PS and WR of all samples were affected by pH except for WR of CGPF. PS and WR of all samples were not affected by incubation temperature except of WR of CGPF. Incubation temperature influenced FB of CGPF and WPC but not of NFDM and SC. Sample concentration significantly affected FB of all samples. CGPF was an effective protein source in terms of WR and FB. For FB, SC &gt; CGPF = NFDM &gt; WPC and for PS, WPC=NFDM=SC &gt; CGPF.

SENSORY, CHEMICAL and BACTERIOLOGICAL STABILITY of FRANKFURTERS CONTAINING MILK PROTEINS and CORN GERM PROTEIN FLOUR

Shelf stability of frankfurters extended with milk proteins and corn germ protein flour (CGPF) stored at 1-2C for 45 days was studied by water activity, sensory evaluation, bacteriological tests, and chemical determinations of total volatile nitrogen (TVN), ammonia nitrogen, and TBA values. the incorporation of milk proteins and CGPF affected shelf stability of frankfurters as determined by sensory characteristics, bacteriological test, and chemical analysis. After 45 days of storage, the frankfurters with CGPF added had a stronger atypical aroma and atypical flavor than the all-meat control and products containing milk proteins. However, the atypical notes were relatively low, up to 10.2 on a 60-point scale, and should be considered as weak and acceptable. the all-meat control had a juicier mouthfeel than the other frankfurters. CGPF-containing frankfurters contained an intermediate count (log 3-4 CFU/g) of psychrotrophic bacteria, whereas the other products contained a low bacteria count (log 0-2 CFU/g) after 45 days of storage. There was no formulation treatment effect on TBA values. TVN in frankfurters increased with increasing storage time. the ammonia contents of treatment and control frankfurters were not different during 45 days of storage.

Emulsifying Capacity and Emulsion Stability of Milk Proteins and Corn Germ Protein Flour

ABSTRACTComparative studies of emulsifying capacity (EC) and emulsion stability (ES) of corn germ protein flour (CGPF), nonfat dry milk (NFDM), whey protein concentrates (WPC), and sodium caseinate (SC) were carried out using response surface methodology. CGPF was an effective stabilizer of fat‐protein‐water emulsions. Tested proteins showed the following trend in EC and ES: SC &gt; WPC = NFDM &gt; CGPF. EC and ES increased with increased concentration of protein. No effect of incubation temperature on EC and ES of these proteins was detected. All protein samples showed a maximum EC at high pH (near 8.0) and 1.0% concentration under test conditions, except NFDM (about pH 7.0). Minimal pH effect on ES was found.

Phenolic Acid Contributions to Taste Characteristics of Corn Germ Protein Flour Products

ABSTRACTPhenolic acids have been proposed to be responsible for sour, bitter, and astringent flavors found in vegetable proteins. Corn germ protein flour (CGPF) was subjected to three treatments, i.e., ethanol‐washing, heat‐treatment, and acid‐washing, to remove phenolic compounds. Sensory descriptive analysis was used to evaluate differences in taste among CGPF products. Eight phenolic acids in the extracts of CGPF samples were identified and quantified by gas chromatography, o‐Coumaric, p‐coumaric, and ferulic acids were the principal phenolic acids in the free and soluble esters fractions of CGPF products. Taste thresholds for the acids were 20, 48, and 90 ppm, respectively. Models were established to predict taste characteristics of CGPF products from phenolic acid content.

Water Retention and Solubility of Soy Proteins and Corn Germ Proteins in a Model System

ABSTRACTResponse surface methodology was used to study water retention and protein solubility of soy flour (SF), concentrate (SC), and isolate (SI), and corn germ protein flour (CGPF). Water retention increased with pH (6 to 8) and incubation temperature (10–70°C), but not with increasing incubation time (10–30 min). SC had highest water retention per gTam, followed by CGPF, SF, and SI. Water retention in relation to protein content was higher in CGPF than in the three soy products. Protein solubility was significantly affected by pH and temperature of incubation. Protein solubility increased when pH (6 to 8) and incubation temperature increased (30–70°C) in all samples. SI had highest protein solubility, and CGPF had the lowest.

Corn Germ Protein Flour as an Extender in Broiled Beef Patties

ABSTRACTBeef patties were extended at levels of 10, 20, and 30% of the uncooked weight with hydrated defatted corn germ protein flour (CGPF). Extended patties had lower cooking losses and higher cooked yields than control patties. Adding CGPF did not affect moisture or fat contents in broiled patties, but lowered protein content. The amino acid composition of experimental patties was comparable to that of the control. The water‐holding capacity and pH of raw patties increased with increasing levels of added CGPF. Incorporation of CGPF affected sensory characteristics of the product; meaty aroma and flavor of all‐meat patties was significantly higher than experimental samples and decreased with an increase in added CGPF. CGPF has potential use as an extender in coarsely ground meats.