bluuebunny/crossref_metadata_2025 huggingface dataset:
Compression Strength of Dairy Gels and Microstructural Interpretation
Authors: AGUILERA JOSÉ M. , KINSELLA JOHN E.
Published: August 2006

Contour plots were developed for the compression stress (at 20% deformation) of single‐component, mixed and filled protein gels. Samples were made by heating and acidification from skim milk powder, SMP (0–20% TS), whey protein isolate, WPI (0–10% TS), and recombined cream, within pH 3.6–3.9, 4.6–4.8 and 5.1–5.3. At higher pH, WPI gels were stronger than SMP gels. WPI had a reinforcing effect on SMP gels, while small additions of SMP to WPI gels resulted in weaker mixed gels. Filled gels containing cream had higher compression strengths than mixed gels. Micrographs showed linking of casein chains by WPI strands in mixed gels and compatibility of fat globules with casein micelles in the protein network of filled gels.
Partial Lipid Extraction of Egg Yolk Powder: Effects on Emulsifying Properties and Soluble Protein Fraction
Authors: CHUNG SIEW LIAN , FERRIER LES K.
Published: August 2006

Egg yolk powder was partly defatted using hexane, 95% ethanol, isopropanol, chloroform‐methanol (2:1, v:v) hexane‐isopropanol (77:23, w:w) and hexane‐ethanol (77:23, w:w). Hexane‐isopropanol was most efficient, extracting more than 50% of the lipid. Protein solubility and emulsifying activity of the extracted powder decreased after extraction. Hexane‐isopropanol reduced emulsifying activity about 14% and protein solubility to 13.8% from 15.7%. Extraction with other solvents resulted in up to 41% loss of emulsifying activity; protein solubility decreased to as low as 3%. Ovalbumin in the water‐soluble fraction of extracted egg yolk powder reduced its emulsifying effectiveness.
Conditions Affecting Emulsifying Properties of Egg Yolk Phosvitin
Authors: CHUNG SIEW LIAN , FERRIER LES K.
Published: August 2006

The effects of protein concentration (0.1–2.0%), oil volume fraction (0.17–0.67), mixing speed (10,000–22,000 rpm) and mixing time (0.5–8 min) on the emulsifying properties of phosvitin and bovine serum albumin (BSA) were compared. Emulsifying activity and emulsion stability increased with protein concentration, oil volume fraction and mixing. Effects of these variables were assessed quantitatively using an empirical equation. Mixing speed had the greatest influence and protein concentration had the least influence on emulsifying activity for both phosvitin and BSA. For emulsion stability, mixing speed had the greatest influence for phosvitin; oil volume fraction had the greatest influence for BSA. Phosvitin was a better emulsifier than BSA at pH7.
Water Binding and Ingredient Dispersion Pattern Effects on Surimi Gel Texture
Authors: CHUNG K.H. , LEE CM.
Published: August 2006

Water binding, thermotransitional properties and the dispersion pattern of ingredients were studied in relation to their texture‐modifying effects in surimi gels. The DSC‐measured bound water (unfreezable at −30°C) of surimi gels prepared with potato starch with and without pregelatinization highly correlated with compressive force (r=0.94) and inversely correlated with expressible moisture (R=−0.99) of the gels. For nonfish proteins, however, physically bound water contributed more than the DSC‐measured bound water to gel strength. The ability to undergo thermal transition (size expansion and water absorption) and dispersion pattern of ingredients were responsible for the differences in texture‐modifying effects.
Effect of Heat Processing on Quality of Pasteurized Oysters
Authors: CHAI T. , LIANG K.T. , PACE J. , SCHLIMME D.V.
Published: August 2006

Constant heating time at different temperatures and constant temperature with different heating times combinations were studied to determine optimum heat process for oyster pasteurization in plastic pouches. Heating 8 min at 75–76°C gave optimum product physical and sensory quality. Crude amylase and peroxidase extracts from oysters were inactivated by optimum treatment, but lipase retained about 15% of activity.
Phenolic Acid Contributions to Taste Characteristics of Corn Germ Protein Flour Products
Authors: HUANG C.J. , ZAYAS J.F.
Published: August 2006

Phenolic 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.
Flow Behavior and Gelatinization of Cowpea Flour and Starch Dispersions
Authors: OKECHUKWU P. E. , RAO M. A. , NGODDY P. O. , MCWATTERS K. H.
Published: August 2006

The flow behavior of a 25% cowpea slurry with 8% oil held at 70°C showed shear‐thinning behavior and an Arrhenius temperature relationship. Cowpea flour (8%) and starch (2.5%) slurries heated for less than 1 min at 70–87°C exhibited shear‐thickening while those heated longer times exhibited shear‐thinning behavior. Maximum viscosities attained due to heat‐induced gelatinization showed a power relationship with temperature of heating. Starch gelatinization kinetics followed a first‐order equation and the temperature dependence of the rate constant followed the Arrhenius relationship with an activation energy of about 47.4 kcal/mol. Heating the slurries for >200 min above 80°C resulted in loss of viscosity.
Characterization of Gamma Irradiated Peanut Kernels Stored One Year Under Ambient and Frozen Conditions
Authors: CHIOU R.Y.‐Y. , SHYU S.‐L. , TSAI C.‐L.
Published: August 2006

Peanut kernels were gamma irradiated at 0, 2.5,5.0,10, and 20 KGy, and stored 1 yr at ambient and frozen (− 14°C) conditions. Irradiated peanuts lost germination capabilities during storage. Molds were detected only on peanuts irradiated with 2.5 KGy and stored at ambient temperature. Peanut oil in kernels stored at − 14°C was comparatively more stable than that in peanuts stored at ambient temperature. Oxidation of oil was not significantly changed by irradiation. Changes in fatty acid content varied slightly with exception of linoleic and linolenic acids which decreased with increased radiation depending on storage temperature. The SDS‐PAGE protein patterns of peanuts revealed no noticeable variation of protein subunits resulting from irradiation and storage.
Thermal Process Lethality Variability In Conduction‐Heated Foods
Authors: WANG JIANJUN , WOLFE ROBERT R. , HAYAKAWA KAN‐ICHI
Published: August 2006

No single method is available to estimate the variability of thermal process lethality (WFp) as a function of all thermal process parameters which significantly influence WFp. Therefore, our work was conducted to develop such a method. This was accomplished through screening and regression simulations/analyses. From 19 independent parameters, 12 significant ones were selected through the analysis. The selected parameters included means of slope index of heating curve (fh), heating medium temperature, and slope index of thermal death time curve (z), and the coefficient variations of fh and z. A polynomial regression equation was developed for estimating WFp as a function of all parameters found significant through the regression simulation/ analysis. The equation was validated experimentally.
Kinetic Parameter Evaluation with Linearly Increasing Temperature Profiles: Integral Methods
Authors: NUNES R.V. , RHIM J.W. , SWARTZEL K.R.
Published: August 2006

Two integral methods for kinetic parameter estimation with linear temperature profiles were tested using simulated and experimental data sets. They were the second rational approximation method (SRAM) and the equivalent point method (EPM) using least squares nonlinear regression (LSNR) and weighted least squares nonlinear regression (WLSNR). For three simulated data sets, the SRAM with WLSNR yielded accurate parameter estimation. For the experimental data set, both SRAM and EPM using WLSNR yielded accurate parameter estimation. The standard error in activation energy were 37.3% (for SRAM) and 46.7% (for EPM) lower than that of the differential method. The SRAM with WLSNR was the best parameter estimation procedure.
Computerized Model for Strain‐Stress Analysis of Food Undergoing Simultaneous Heat and Mass Transfer
Authors: TSUKADA TAKAO , SAKAI NOBORU , HAYAKAWA KAN‐ICHI
Published: August 2006

A computerized method was developed for simulating transient state heat and moisture transfer and stress distribution in axisymmetric food undergoing drying process. For this development, a simultaneous heat and moisture transfer model was coupled with the virtual work principle applicable to a body undergoing volumetric changes. The developed method was verified by comparing experimental results with those predicted. Experimental results were obtained by drying cylindrically formed samples of hydrated starch granules. They included central temperature, average concentration histories and photographically observed internal crack formations.
Thermal Denaturation in Fish Muscle Proteins During Gelling: Effect of Spawning Condition
Authors: BEAS VIVIANA E. , WAGNER JORGE R. , AÑON MARÍA C. , CRUPKIN MARCOS
Published: August 2006

We studied thermal denaturation of myofibrillar proteins from pre‐and post‐spawning hake by differential scanning calorimetry (DSC), and evaluated denaturation kinetics under both conditions. The denaturation enthalpies of all pre‐spawning fish muscle extracts were less than those from post‐spawning. The area under the DSC thermogram corresponding to myosin denaturation was smaller in myofibrillar extracts from pre‐spawning than from post‐spawning hake, while the areas corresponding to denaturation of actin were similar. Between 40 and 55°C the myosin denaturation rates were greater for post‐spawning than for pre‐spawning hake. Both entalphies and kinetic data indicated proteins of fish in a better biological condition (post‐spawned) denature more rapidly and completely.
Purification and Characterization of Proteases from Digestive Tract of Grass Shrimp (Penaeus monodon)
Authors: JIANG SHANN‐TZONG , MOODY MICHAEL W. , CHEN HSING‐CHEN
Published: August 2006

Proteases in grass shrimp (Penaeus monodon) digestive tract were extracted. Four fractions, A, B, C and D, demonstrated caseinolytic activity and were purified to electrophoretic homogeneity. A, C and D were trypsin‐like, while B was a chymotrypsin‐like protease. Optimal temperature for proteases A, B and C were 65°C, and that for D was 55°C for hydrolysis of casein. Optimal pH of proteases A and C was 8.0, and that of D was 7.0 for hydrolysis of p‐toluenesulfonyl‐L‐arginine methyl ester. Optimal pH of protease B for hydrolysis of N‐benzoyl‐L‐tyrosine ethyl ester was 8.0. Inactivation of 50 % enzyme activity in 5 min occurred at 67°C for protease B and 50°C for proteases A, C and D.
Effect of Sodium Lactate on Microbial and Chemical Composition of Cooked Beef during Storage
Authors: PAPADOPOULOS L. S. , MILLER R. K. , ACUFF G. R. , VANDERZANT C. , CROSS H. R.
Published: August 2006

Cooked, vacuum packaged beef top rounds injected with 0, 1, 2, 3 or 4% sodium lactate were stored up to 84 days at 0°C. Aerobic plate counts (APC), water activity, pH and lactic acid content were determined at 14‐day intervals. Microbial distributions were characterized following 0.56 and 84 days storage. Increasing sodium lactate resulted in reduction in APC. Water activity was not affected by sodium lactate level. Decreases in pH were minimized at sodium lactate >3%. Initially, the microflora of roasts consisted primarily of Micrococcus and coagulase‐negative Staphylococcus spp. After 84 days the microflora consisted primarily of hetero‐ and homofermentative Lactobacillus spp. No differences in APC, lactic acid content, pH or water activity occurred between top rounds with 3 and 4% sodium lactate. Cooked, refrigerated roast beef injected with up to 3 or 4% sodium lactate had microbial shelf‐life up to 84 days.
Comparison of Rapid Methods for isolation and Enumeration of Clostridium perfringens in Meat
Authors: ALI MOHAMMED S. , FUNG DANIEL Y. C. , KASTNER CURTIS L.
Published: August 2006

Three strains of Clostridium pefringens, ATCC 12924, ATCC 12917, and ATCC 14809, were inoculated separately into thioglycollate broth and ground beef samples and enumerated by Fung's Double Tube (FDT), Oxyrase Enzyme (OE), Gas Pak Anaerobic System (GPAS), and Anaerobic Petri Dish (APD) methods. Recovery of the three strains by FDT was significantly higher (P < 0.05) than that by the other three methods from both thioglycollate broth and ground beef, with OE second highest. FDT gave better recovery (84%) in less time (8–10 hr) at 42°C compared with the OE method (61%). FDT was also least costly.
Effect of Gamma Irradiation of Whole Chicken Carcasses on Bacterial Loads and Fatty Acids
Authors: KATTA SEKHAR R. , RAO D.R. , SUNKI G.R. , CHAWAN C.B.
Published: August 2006

Broiler chickens were irradiated by Cobalt‐60 at a commercial irradiation facility at dose levels of 0.0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kGy at 3.0°C. Regression analyses indicated more than 99% of the microbial load on the whole carcass was eliminated at doses ranging from 1.5 to 2.0 kGy. Fatty acids were not affected except for palmitic which showed a decrease and oleic acid which showed an increase. Both of those changes were significant. Results indicate gamma irradiation of chicken at 2.0 kGy or more using commercial irradiation substantially reduced bacterial loads.
Thermal Resistance of Egg‐Associated Epidemic Strains of Salmonella enteritidis
Authors: SHAH D. B. , BRADSHAW J. G. , PEELER J. T.
Published: August 2006

Seventeen strains of Salmonella enteritidis isolated from patients and various implicated products from 5 egg‐associated outbreaks of salmonellosis were investigated for plasmid content, phage type and thermal resistance. D values obtained at 57.2 and 60°C in liquid whole egg for all strains were within ranges reported by previous investigators. Sublethal heat shock at 40°C for 2 hr or 48°C for 30 min increased thermotolerance 2‐ to 3‐fold. The induced thermotolerance decayed to control levels after 2–3 cycles of cell duplication at a lower temperature. Most strains contained a 39‐Mda plasmid and were phage type 8. No correlation was observed between thermotolerance and presence or absence of plasmid or phage type.
Monitoring Chemical and Microbial Changes of Cottage Cheese using a Full‐history Time‐temperature Indicator
Authors: SHELLHAMMER T.H. , SINGH R.P.
Published: August 2006

Cottage cheese (4% milkfat) was stored under three isothermal conditions (3, 9, and 15°C) and one varied temperature condition for the length of its useful shelf life–up to 32 days. Attached to each one‐half pint carton were two full history, enzymatic based, time‐temperature indicators (I‐POINT models #4014 and #4021). Throughout the study quality attributes of the cottage cheese, as determined by chemical and microbial means, and the indicator progress were periodically monitored. The cheese spoiled due to growth of acid‐forming bacteria under the warmer conditions and due to psychrotrophic bacteria under the coldest condition. Response of the I‐POINT model 4014 was significantly related to changes in three of the quality attributes of the cottage cheese, specifically: pH, standard plate count when the cheese was stored at 8.8° C, and titratable acidity when the cheese was stored at 15.1° C.
Control of Minimally Processed Carrot (Daucus carota) Surface Discoloration Caused by Abrasion Peeling
Authors: BOUN H.R. , HUXSOLL C.C.
Published: August 2006

Abrasion peeling of carrots results in formation of a white lignin type material on the surface during storage. The degree of its formation was directly related to severity of abrasion during peeling. Dipping the peeled product for 30 seconds in a 70°C. Acidic or basic solution (citric acid or sodium hydroxide), retarded formation of the material. The low pH dip did not cause flavor changes.
Changes During Storage of Oranges Pretreated with Nitrogen, Carbon Dioxide and Acetaldehyde in Air
Authors: SHAW PHILIP E. , MOSHONAS MANUEL G. , PESIS EDNA
Published: August 2006

Hamlin, Pineapple and Valencia oranges were stored in controlled atmospheres (CA) of nitrogen, carbon dioxide or 0.1–0.7% acetaldehyde in air 8–24 hours and changes in seven volatiles during 0–8 days determined by gas chromatography. Increases in acetaldehyde, ehtyl acetate, ethyl butyrate and ethanol were noted in samples after nitrogen or carbon dioxide CA storage with maximum increase 1–2 days after treatment. Methanol, methyl butyrate and hexanal were unchanged. Flavor evaluations of control versus treated juice showed no consistent changes from any treatment. Acetaldehyde vapors had little effect on flavor or compositon, except for Hamlins, where acetaldehyde and ethyl butyrate levels increased.
Chemical Changes during Storage of an Alcoholic Orange Juice Beverage
Authors: RODRIGUEZ M. , SADLER G.D. , SIMS C.A. , BRADDOCK R.J.
Published: August 2006

Chemical stability of a pasteurized, noncarbonated, alcoholic orange juice beverage, (8% ethanol and 30% reconstituted Valencia frozen concentrated orange juice), was investigated. It was hot‐filled into clear glass bottles under nitrogen and subjected to 14‐wk storage at 4, 25, and 40°C. pH, °Brix, titratable acidity, and % alcohol remained constant throughout storage. Accumulation of furfural and darkening paralleled ascorbic acid degradation. The beverage exhibited 25 times more browning at 40°C and 9 times more at 25°C than at 4°C after 14‐wk. d‐Limonene decreased at all temperatures. Nitrogen headspace slightly improved stability at 40°C. Time and temperature were most significant in storage and long‐tem shelf‐life could only be achieved with refrigeration.
Color of Pregelatinized Pasta as Influenced by Wheat Type and Selected Additives
Authors: COLE M. E. , JOHNSON D. E. , COLE R. W. , STONE M. B.
Published: August 2006

A high temperature‐short time, twin‐screw extrusion process was utilized to manufacture pregelatinized pasta on a pilot‐plant scale. Effects of wheat type and selected additives on color properties of dry and rehydrated pasta products were evaluated by instrumental means. Wheat type most strongly influenced instrumental color values of pregelatinized pasta. Formulation of pasta with 1.0% disodium phosphate increased saturation index of dry pasta while addition of 5.0% wheat gluten increased lightness index of rehydrated pasta. Raising levels of glyceryl monostearate from 0.75 to 2.0% increased lightness of dry and rehydrated products.
Enzyme Inactivation Improves Stability of Self‐Rising Corn Meals
Authors: BOOKWALTER GEORGE N. , LYLE STEVEN A. , NELSEN TERRY C.
Published: August 2006

Enzymes affecting corn lipids were inactivated by adjusting whole dent corn to 15% moisture and gradually heating it to 91° or 96°C during passage through a two‐stage steam‐jacketed conveyer, followed by cooling. Heat‐processed and untreated products were then milled by a four‐break, 96% extraction procedure. Processed and untreated meals were formulated into self‐rising meals and stored at 37°C for 6 months. Processed meal formulations were significantly (P < 0.05) more stable during storage than those from untreated meal as indicated by lower fat acidity values and greater carbon dioxide retention. Corn bread prepared from stored enzyme‐inactivated meal had greater volume and maintained more uniform shape than that from stored untreated meal.
Feed‐back Temperature Control System for Microwave Ovens Using a Shielded Thermocouple
Authors: RAMASWAMY H. , VAN DE VOORT F.R. , RAGHAVAN G.S.V. , LIGHTFOOT D. , TIMBERS G.
Published: August 2006

A dynamic system was developed and evaluated to continuously monitor product temperature in ovens using an aluminum shielded thermocouple. The signal was processed by a computer controlled feedback relay to turn the magnetron on or off relative to a preselected setpoint. Results indicated the temperature of water (> 100 mL) could readily be maintained within 1°C of the setpoint. Temperatures for small samples (∼5 mL) could also be controlled, however, they required use of an additional microwave heat‐sink in the oven cavity to prevent temperature overshooting. The thermocouple based feed‐back temperature control system worked well and provided a simple way to control sample temperature in a microwave oven.
Solubility and Viscous Properties of Casein and Caseinates
Authors: KONSTANCE R.P. , STRANGE E.D.
Published: August 2006

An integrated study was conducted on the effects of temperature, pH, salt type and concentration on the functionality of sodium caseinate, calcium caseinate and rennet casein. At 5.6 ≤ pH ≤ 6.2, all proteins exhibited greatest solubility when sodium phosphate was added. Viscosities under these conditions were one to two orders of magnitude greater than solutions at pH < 4.6. Protein solutions and viscosities with added sodium phosphate were not temperature dependent.
Iron in Food: Effect of Continued Use of Iron Cookware
Authors: CHENG Y.J. , BRITTIN H.C.
Published: August 2006

Two foods (applesauce and spaghetti sauce) were each cooked in an iron skillet 50 times and in a noniron untensil three times. Duplicate samples of the raw (three replications) and cooked foods were dried, ashed, and analyzed for moisture and iron content. Iron was determined by atomic absorption spectrophotometry. Iron in foods cooked in iron utensils was greater than that in foods cooked in noniron utensils through continued use of the iron utensils for 50 times.
Relationship of Loss of Membrane Functionality and Hard‐to‐Cook Defect in Aged Beans
Authors: RICHARDSON J.C. , STANLEY D.W.
Published: August 2006

Microsomal membranes were prepared from fresh beans (Phaseolus vulgaris) and from samples kept 9 mo at various temperatures and humitidies. Increasing storage severity produced progressively hard‐to‐cook (HTC) beans as well as higher solids loss and lower water‐holding capacity during soaking. Membrane phase transition temperature (PTT), calcuated from spin label electron paramagnetic resonance data, also increased and showed a highly significant (r = 0.997) correlation with cooked hardness. Fatty acid analysis of membrane lipids demonstrated higher PTT values were due to a significant increase in proportion of saturated fatty acids. These data reflect membrane deterioration during aging that could explain solids loss and water‐holding capacity changes. Changes in the membrane may be the primary event in initiation of the HTC defect.
Thiamin, Riboflavin and Niacin Retention in Cooked Cowpeas as Affected by Kanwa Treatment
Authors: UZOGARA S.G. , MORTON I.D. , DANIEL J.W.
Published: August 2006

Retention of three water soluble B‐vitamins in dry cowpeas cooked with a local tenderizer, named “kanwa,” were investigated. Results showed cooking (100°C) in kanwa or sodium bicarbonate decreased levels and retention of vitamins compared to controls cooked in water. Levels of vitamins in kanwa‐cooked cowpeas were not significantly different from those in NaHCO3 cooked samples. Retention in the alkaline cooking processes ranged 15–20% (thiamin), 26–49% (niacin) & 53–64% (riboflavin). Soaking followed by boiling at 100°C or pressure cooking (121°C) increased levels and retention of vitamins.
Changes in Size and Composition of Protein Aggregates on Heating Reconstituted Concentrated Skim Milk at 120oC
Authors: SINGH HARJINDER , CREAMER LAWRENCE K.
Published: August 2006

Treatment at 120oC caused initial transfer of protein from the serum and small micelle fraction to the medium‐sized micelle fraction. More extensive heating caused transfer of protein from the medium fraction to the large‐sized micelle fraction, and the serum fraction as 'soluble’casein. Protein composition of large‐sized micelle fraction remained essentially constant, but for the other fractions it changed throughout the heating period. Experiments with heated milks that had been made free of colloidal calcium phosphate (CCP) showed that a proportion of the calcium phosphate in milk, whether indigenous or precipitated by heating, became less soluble. This‘insoluble’calcium phosphate was possibly involved in joining the smaller protein particles into larger‐sized aggregates.
Stability of Aspartame in Fruit Preparations Used in Yogurt
Authors: FELLOWS J.W. , CHANG S.W. , SHAZER W.H.
Published: August 2006

Stability of aspartame (APM) in three fruit preparations stored 6 months at three temperatures was assessed monthly. Remaining aspartame, microbiological quality, objective color and pH were determined; sensory acceptance tests were conducted with the fruit added to a commercial yogurt. pH or microbiological counts did not change during storage. About 60% of original APM remained after 6 months at 21.1°C. APM level was a function of pH, temperature and time. Based on the tests, shelf life estimates for the fruit preparations were 1½ months at 32.2°C, 4–6 months at 21.1°C, and > 6 months at 4.4°C.
Nutritional Evaluation with an Animal Model of Cottage Cheese Fortified with Calcium and Guar Gum
Authors: KAUP SUSAN M. , GREGER J.L. , LEE KEN
Published: August 2006

Apparent absorption of calcium by rats from cottage cheese was very efficient under the conditions tested. However, overall calcium retention and, to a lesser extent, bone calcium content increased with each increment in dietary calcium. Despite sensitivity of the model to variation in calcium intake, no effect of guar gum on calcium utilization was noted. Increasing the calcium added to cottage cheese increased phosphorus retention, did not antagonize utilization of magnesium and zinc, and only slightly decreased iron utilization in rats.
Microfiltration Affinity Purification of Lactoferrin and Immunoglobulin G from Cheese Whey
Authors: CHEN JYH‐PING , WANG CHENG‐HSIN
Published: August 2006

A process combining affinity chromatography with membrane filtration was used to isolate lactoferrin and immunoglobulin G from Cheddar cheese whey. Heparin Sepharose, protein G Sepharose, and protein G bearing Streptococcal cells were used as adsorbents to form affinity complexes with target proteins. These could be retained by 0.2 μm microfiltration membranes and separated from unbound whey proteins. Binding capacities and binding constants of adsorbents determined by Langmuir‐type adsorption isotherms were 124 mg/mL gel and 5.4 × 10−6M for heparin Sepharose, 17.8 mg/mL gel and 3.5 × 10−7M for protein G Sepharose, and 148 μ.g/mL cell suspension and 1.1 × 10−7M for protein G cells. Lactoferrin with 95% purity and 92% iron‐binding capacity, and immunoglobulin G with 90% purity and 86% activity could be obtained with reasonable yields.
Chickpea Protein Isolates: Physicochemical, Functional and Nutritional Characterization
Authors: PAREDES‐LÓPEZ O. , ORDORICA‐FALOMIR C. , OLIVARES‐VÁZQUEZ M.R.
Published: August 2006

Proteins were isolated from chickpea flour by micellization and isoelectric precipitation techniques. Protein content ranged from 84.8‐87.8%. Denaturation temperature and transition enthalpy, by differential scanning calorimetry, were higher for micelle than for isoelectric proteins. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis showed a molecular weight distribution between 16.6‐66.4 kD for micelle and 14.9‐84.2 kD for isoelectric proteins. Most functional properties compared favorably to a commercial soy isolate. In general, most essential amino acids of chickpea isolates were at acceptable levels compared to a reference pattern. High values of in vitro digestibility and calculated PER were obtained for the isolates.
Chemical Detoxification of Aflatoxin‐containing Copra
Authors: MERCADO C.J. , REAL M.P.N. , ROSARIO R.R. DEL
Published: August 2006

Aflatoxin‐containing copra at moisture contents of 24% and 7% was effectively detoxified by ammonium hydroxide (> 97% and 89% reduction, respectively). Detoxification was accomplished in 5 days using 1.5% ammonium hydroxide (ammonia/copra); in 10 days using 1.0% and in 15 days using 0.5%. The initial aflatoxin B1 concentration of 500 ppb (9% moisture) was reduced to ≤ 20 ppb. Detoxification trials using a screw expeller showed 67% reduction in aflatoxin content of the oil with 1.0% ammonia.
Inactivation of Pectinesterase in Orange Juice by Supercritical Carbon Dioxide
Authors: BALABAN MURAT O. , ARREOLA A.G. , MARSHALL M. , PEPLOW A. , WEI C.I. , CORNELL J.
Published: August 2006

Single strength orange juice was treated with supercritical carbon dioxide (CO2) and the effect of process time, temperature and pressure on pectinesterase (PE) activity was determined. PE could be inactivated with supercritical CO2 below temperatures necessary for thermal inactivation. Higher pressure, temperature and longer treatment time resulted in more inactivation. Inactivation kinetics showed activation energy was significantly reduced at SC C02 treatment at 31 MPa (97.4 KJ/mole), compared to identical treatments at atmospheric pressure (166.6 KJ/mole). D values ranged from 2673 min at atmospheric pressure and 40°C to 10 min at 31 MPa and 60°C. z value at atmospheric pressure was 8.8C°, and at 31 MPa 5.2C°.
Rheological Properties of Heat‐induced Gels from Egg Albumen Subjected to Freeze‐thaw
Authors: DILL C.W. , BROUGH J. , ALFORD E.S. , GARDNER F.A. , EDWARDS R.L. , RICHTER R.L. , DIEHL K.C.
Published: August 2006

A back‐extrusion device was used to measure gel strength, elasticity, and viscosity index of heat‐induced gels of albumen maintained at 80°C from 5 to 30 min. These rheological properties were the same in albumen refrigerated 24 hr at 3°C as those observed in gels from fresh albumen suspensions. Short term frozen storage (−10°C for 24 hr) significantly reduced each gel parameter compared with fresh (control) albumen gels. Incorporation of sucrose into fresh albumen protected rheological properties of the heat‐induced gels from deleterious effects of freezing the albumen suspensions. Addition of 5 or 10% NaCl to albumen reduced or eliminated the ability of albumen to form heat‐induced gels.
Curdlan: Properties and Application to Foods
Authors: NAKAO YUKIHIRO , KONNO AKIRA , TAGUCHI TETSUYA , TAWADA TOSHIO , KASAI HIROSHI , TODA JUN , TERASAKI MAMORU
Published: August 2006

Gel formation of curdlan at 100–130°C and behaviors of curdlan gels under frozen state were investigated by measuring gel strength and syneresis. Even when aqueous suspensions of curdlan were heated to 100°C or higher, they formed a gel, and gel strength increased with temperature. Curdlan gel was also stable against freezing and thawing. The syneresis of a 4% curdlan gel after freezing and thawing was reduced from 20.6% to about 2.1% by addition of 5% waxy corn starch and to 8.9% by addition of 20% sucrose. Suggested by these findings, new applications to foods have been developed, especially those subject to retorting and/or freezing.
Effects of Constituent Concentration on Rheological Properties of Corn Oil‐In‐Water Emulsions
Authors: SUZUKI KANICHI , MAEDA TAKUYA , MATSUOKA KUNIHIKO , KUBOTA KIYOSHI
Published: August 2006

Rheological properties were studied with a tube viscometer. Emulsifying agents were soy lecithin and Tween 20. The volume concentration of dispersed phase, φ, ranged from 0.32‐0.62. The emulsions behaved as pseudoplastic fluids. The flow behavior index, n, of the lecithin emulsions increased slightly with increasing φ and concentration of emulsifying agent, Ce. However, the n values of Tween 20 emulsions were nearly constant. Apparent viscosity of the emulsions increased with increase of φ and Ce. With φ constant the apparent viscosity was still strongly affected by Ce.
Interacting Effects of pH and NaCl on Heat Resistance of Bacterial Spores
Authors: HUTTON MICKI T. , KOSKINEN MARY ANN , HANLIN JOHN H.
Published: August 2006

Spores of PA3679 (C. sporogenes) and Clostridium botulinum 213B were less heat resistant when heated in a menstruum of decreasing pH. The D value of the spore population decreased by 50% when heated in pH 5.0 buffer compared to pH 7.0 buffer. Addition of NaCl to the recovery medium reduced the number of colony forming units in a population of heated spores. Presence of NaCl at 2.0% in the recovery medium decreased the spore D‐value by 20‐40% irrespective of pH of the heating menstruum. Combined effects of pH and NaCl could be illustrated by three‐dimensional histograms.
Plasma Cholesterol Oxidation Products (Oxysterols) in Human Subjects Fed a Meal Rich in Oxysterols
Authors: EMANUEL H.A. , HASSEL C.A. , ADDIS P.B. , BERGMANN S.D. , ZAVORAL J.H.
Published: August 2006

There is no evidence whether humans absorb cholesterol oxidation products (COPS) from food sources. Therefore, (after‐meal) absorption of COPS in humans was studied following consumption of a powdered egg meal containing 30–90 ppm each of four different COPS. Both total plasma and plasma chylomicron COPS concentrations increased. By contrast, subjects consuming fresh eggs containing very low levels of the same four COPS (0–2 ppm) demonstrated no significant rise in plasma COPS. We concluded that the human subjects studied had the capacity to absorb COPS from food sources. The brief residence time of COPS observed in both chylomicrons and plasma suggested rapid transfer of COPS among lipoprotein fractions and/or clearance from plasma.
Role of Light Chains In Heat‐Induced Gelation of Skeletal Muscle Myosin
Authors: MORITA JUN‐ICHIRO , OGATA TOMOHIRO
Published: August 2006

More than 60% of alkali light chains were released from rabbit skeletal myosin during heating to form gel. The removal of about 1 mol of regulatory light chain (LC2)/mol of myosin (LC2‐deficient myosin) resulted in major decrease of gel strength at low ionic strength. The F‐actin concentration required to attain maximum gel strength of the LC2‐deficient myosin was greater than that of control myosin. These changes in functional characteristics of myosin induced by removal of LC2 were restored by reassociation of LC2 to the LC2‐deficient myosin. Results showed skeletal myosin LC2 has an important role in its heat‐induced gelation.
Soluble, Dialyzable and Ionic Calcium in Raw and Processed Skim Milk, Whole Milk and Spinach
Authors: REYKDAL OLAFUR , LEE KEN
Published: August 2006

Chemical availability of calcium was measured with and without simulated digestion to determine processing effects. Available calcium was low in spinach and significantly higher in skim milk and whole milk, consistent with their known bioavailabilities. In nondigested processed milk it was significantly higher for whole milk than for skim milk. However, available calcium in digested whole milk was lower than in digested skim milk. Digestion increased available calcium in skim milk, dialyzable and ionic dialyzable calcium in whole milk and ionic calcium in spinach. Soluble and ionic soluble calcium were lowered in whole milk during digestion due to soap formation. Effects on % calcium were slight, but available calcium in nondigested skim milk was significantly lowered by processing.
Reduction of Heat Resistance of Neosartorya fisheri Ascospores by Sulfur Dioxide
Authors: SPLITTSTOESSER D.F. , CHUREY J.J.
Published: August 2006

The influence of sulfur dioxide on heat resistance was measured in 0.05 M, pH 3.3 tartaric acid solution and in various fruit juices. In tartaric acid solution, as little as 5 mg/L SO2 had a detectable effect; 100 mg/L reduced D80 from 123 min to 6.1 min, and at the 100 mg/ L, temperatures as low as 65°C caused a lethality. In fruit juices, 100 mg/L reduced heat resistance by 50% or more. Raising the pH from 3.3 to 5.0 neutralized the activity of sulfur dioxide indicating that it was the undissociated, molecular form that sensitized the ascospores to heat.
Production of Citric Acid from Beet Molasses by Immobilized Cells of Aspergillus niger
Authors: ROUKAS T.
Published: August 2006

Citric acid was produced from beet molasses by immobilized cells in shake flasks and glass bioreactor. Maximum concentration of citric acid (35 g/L) was observed from immobilized A. niger cells in shake flasks after 28 days fermentation. In repeated batch fermentations, the A. niger cells entrapped in Ca‐alginate gel beads retained ability to produce citric acid for up to 84 days.
Kinetics of Growth and Inhibition of Listeria monocytogenes in the Presence of Antioxidant Food Additives
Authors: YOUSEF AHMED E. , GAJEWSKI RONALD J. , MARTH ELMER H.
Published: August 2006

Listeria monocytogenes strain Scott A in Tryptose Broth was treated with 100‐300 ppm butylated hydroxyanisole (BHA), 300‐700 ppm butylated hydroxytoluene (BHT) and 10‐30 ppm tertiary butylhydroquinone (TBHQ). Resulting growth curves were fitted using the logistic model, and growth parameters [lag period (LP), generation time (GT), and maximum growth (MG)] were calculated. BHA and BHT inhibited Listeria monocytogenes by increasing LP and GT and decreasing MG. Extent of inhibition was concentration‐dependent for cultures with BHA, but not with BHT. TBHQ at 10‐30 ppm increased LP but did not affect other parameters. LP increased exponentially with increased BHA or TBHQ in Listeria culture. Concentrations of additive required to increase LP by one order of magnitude were 240 ppm for BHA and 26 ppm for TBHQ.
Degradation of Aspartame in Yogurt Related to Microbial Growth
Authors: KELLER S. E. , NEWBERG S. S. , KRIEGER T. M. , SHAZER W. H.
Published: August 2006

Three commercial yogurt cultures and strains of Lactobacillus bulgaricus and Streptococcus thermophilus isolated therefrom were evaluated for their effect on aspartame degradation during and after fermentation. The rate of aspartame loss was related to growth of the organisms. Differences in losses due to strain type did not appear signficiant. Aspartame degradation rates were correlated to metabolic rate of the culture. As the rate decreased, loss of aspartame decreased. As a result, less than 10% aspartame was degraded during 6 wk refrigerated storage. Results indicate aspartame should remain stable in yogurt, provided it is added after fermentation.
Effects of Steam/Air Mixtures on a Convection‐Heating Product Processed in a Steritort
Authors: DENISTON M. F. , KIMBALL R. N. , PEOERSEN L. D. , GEE M. , PARKINSON K. S. , JONES H. C.
Published: August 2006

Effects of residual air were evaluated on the heating rates of a convectionheating product processed in a continuous rotary sterilizer. Heat penetration tests were conducted in a Steritort at various reel speeds (1‐10 rpm) and air overpressures (0‐69.0 kPa) using 211 × 300, 300 × 407 and 603 × 700 cans containing Washington white beans in brine. Sterilization times calculated by Ball's formula method were longer for test cans processed with overpressure than those processed with no overpressure. Maximum reduction in calculated lethality for 69.0 kPa air overpressure was 15.2% for 211 × 300 and 300 × 407 experiments and 49.4% for 603 × 700 experiments. For each can size and reel speed, average process time was a linear function of overpressure.
Effects of Extrusion Conditions on Sensory Properties of Corn Meal Extrudates
Authors: CHEN JING , SERAFIN FLORENCE L. , PANDYA RAJESH N. , DAUN HENRYK
Published: August 2006

Yellow corn meal was extruded in a ZSK‐30 Werner and Pfleiderer twin screw extruder. Experiments used a surface response method which included variations in screw speed (100‐300 rpm), heating temperature (100‐200°C) and moisture (20‐30%) in the feed. Descriptive sensory analysis characterized appearance, aroma, flavor and texture of extrudates. Temperature was the most significant factor affecting Munsell value, airiness, toasted corn aroma, and flavor, denseness, crispiness, chewiness and hardness of extrudates. Temperature and feed moisture had significant effects on Munsell value, surface texture, raw flour aroma, toasted corn aroma and flavor, chewiness and hardness. Interaction between temperature and screw speed had significant effects on airiness and denseness of extrudates.
Cooking Quality of Brown Rice as Influenced by Gamma Irradiation, Variety and Storage
Authors: SABULARSE V.C. , LIUZZO J.A. , RAO R.M. , GRODNER R.M.
Published: August 2006

Two long grain and one medium grain brown rice varieties were gamma‐irradiated at 1.0 and 2.0 kGy to ascertain if cooking time could be decreased and to determine effects of storage on chemical and physical characteristics. A tendency toward decreased cooking time was observed as dose level increased. Cooking time was not significantly (P> 0.05) affected by storage. A trend was noted in water uptake ratios, soluble starch of residual cooking water and volume expansion due to irradiation. Storage of irradiated rice produced similar changes to those of nonirradiated rice. Variety also contributed to differences in irradiated samples, such as cooking times, water uptake, starch retention and grain volume expansion.
Extrusion Cooking of Corn/Soybean Mix in Presence of Thermostable α‐Amylase
Authors: LIKIMANI T. A. , SOFOS J. N. , MAGA J. A. , HARPER J. M.
Published: August 2006

A fractional factorial experiment of a 34second order orthogonal design was used to study properties of extrusion processed corn/soybean (70/30%, w/w) mixtures in presence of thermostable α‐amylase. The viscosity of gruels made from extrudates of corn/soybean mixtures with no added α‐amylase was more than 1000‐fold higher than that of products extruded with added enzyme. Changes in viscosity and water solubility and absorption indices of slurries from extrudates made under different conditions, indicated enzymatic starch hydrolysis was increased in the extruder when a‐amylase was included. The results should be useful in selecting extrusion conditions to yield low viscosity‐high nutrient density gruels from extruded products.
Yield and Quality of Tofu as Affected by Soybean and Soymilk Characteristics: Glucono‐delta‐lactone Coagulant
Authors: SHEN C. F. , DE MAN L. , BUZZELL R. I. , MAN J. M. DE
Published: August 2006

Nine light hilum soybean [Glycine max (L.) Merr] cultivars were used to study characteristics that affect yield and quality of tofu (soybean curd) coagulated with glucono‐delta‐lactone (GDL). Pressed and packed (nonpressed) curds were examined. Yield of tofu was not affected by size of beans. Protein and total solids in soymilk increased when protein and moisture increased in soybeans. Yield of pressed GDL tofu increased with protein content of soybeans (or soymilk) plus decreased calcium content. Fracturability of pressed GDL tofu increased with levels of phosphorus. Hardness of packed tofu increased with protein content in soymilk. Yield of pressed GDL tofu was 20% higher than CaSO4 tofu.
Effect of Zn Concentration, Ca Source, Percent Milkfat and Homogenization on Ca, Fe and Zn Solubility in Wheat Cereal Systems under Simulated Gastrointestinal pH
Authors: NADEAU D. B. , CLYDESDALE F. M.
Published: August 2006

An in vitro sequential pH treatment, simulating the gastrointestinal tract, was used to evaluate effects of Zn fortification, source of Ca and milk type (skim, 1 and 2% fat, homogenized and unhomogenized whole) on Ca, Fe and Zn solubility in moderately (MF) and highly fortified (HF) whole wheat cereals. In both cereals, soluble Zn significantly increased in response to fortification level. While CaCO3‐supplemented skim milk promoted mineral solubility in all MF systems, whole milk was most effective in the HF systems. This effect was apparently related to % milkfat and the homogenization process.
Simultaneous Analysis of Biogenic Amines in Canned Fish by HPLC
Authors: YEN GOW‐CHIN , HSIEH CHIU‐LUAN
Published: August 2006

A simple HPLC method was developed for simultaneous determination of putrescine, cadaverine, tryptamine, 2‐phenylethylamine, spermidine, spermine, histamine, tyramine, and agmatine. Amines were derivatized with benzoyl chloride and separated well on Lichrosphere are 100 RP‐18 column using a gradient elution system with a mixture of methanol and water in 10 min. Amine content of canned fish was detected by this method, and except for anchovie products most samples contained the nine amines at low levels. This method would be useful for detection of amines in fish.
Characterization of Common Squid Using Several Freshness Indicators
Authors: OHASHI EIJI , OKAMOTO MIYUKI , OZAWA AKIO , FUJITA TAKAO
Published: August 2006

Changes in several components and properties were examined to find appropriate indicators of freshness of common squid during storage at 0°C, 5°C and 10°C. Total viable counts of bacteria, pH and volatile basic nitrogen did not change significantly during 2 wk storage at 0°C. Unlike usual fish meat, K value in squid muscle changed very quickly, but Hx/AMP ratio was a better indicator. Agmatine increased before initial decomposition started but was not suitable as an early freshness indicator. Free basic amino acids, arginine and ornithine also changed rapidly. Basic amino acids such as arginine and ornithine appeared to be appropriate indicators of freshness of common squid.
Control of Salmonella typhimurium, Listeria monocytogenes, and Escherichia coli 0157:H7 on Beef in a Model Spray Chilling System
Authors: DICKSON JAMES S.
Published: August 2006

Simulated water spray chilling cycles were modified to include acetic acid as a sanitizer. The modified cycles were tested for effectiveness in reducing levels of S. typhimurium, L. monocytogenes, and E. coli 0157:H7 on beef lean and fat tissue. Reductions of up to 3 log cycles were obtained for all three bacterial species on fat tissue. Reduction was less on lean tissue with the same treatments, although the modified cycles reduced populations when compared to the control cycle.
Vitamins E and C Improve Pigment and Lipid Stability in Ground Beef
Authors: MITSUMOTO M. , FAUSTMAN C. , CASSENS R.G. , ARNOLD R.N. , SCHAEFER D.M. , SCHELLER K.K.
Published: August 2006

Effect of vitamin E (Vit E), vitamin C (Vit C) and their combination (Vit E + C) on pigment and lipid stability in raw ground beef was studied during 7 days illuminated display at 4°C. Oxidations of pigment and lipid were greatest in controls. Vit E treatment showed moderate pigment and lipid oxidation, and Vit C treatment showed low pigment and lipid oxidation. Vit E+C treatment resulted in the lowest pigment and lipid oxidation.
Assessment of Sodium Lactate Addition to Fresh Pork Sausage
Authors: LAMKEY J. W. , LEAK F. W. , TULEY W. B. , JOHNSON D. D. , WEST R. L.
Published: August 2006

Sodium lactate was added to fresh pork sausage to determine its effect on refrigerated storage of chubs and retail display of patties. An additional treatment evaluated effects of sodium lactate in fresh sausage with added textured soy concentrate. In fresh sausage stored as 454g chubs, surface discoloration was reduced (P<0.01) and off‐odor development abated (P<0.01) with addition of sodium lactate. The lag phase of microbial growth was extended from 10 to 20 days with sodium lactate. Under retail conditions, sodium lactate did not affect lean color (P>0.01) but resulted in more rapid surface discoloration (P<0.01). Presence of textured soy concentrate decreased (P<0.01) effectiveness of sodium lactate against microorganisms.
Microbial Effects of Ultrasonication of Broiler Drumstick Skin
Authors: SAMS A. R. , FERIA R.
Published: August 2006

Pre‐chill broiler drumsticks were exposed to ultrasonic energy in water at 25 and 40°C for 15 and 30 min to study the effect on skin microbial counts. Aerobic plate counts (APC) after 0, 7, and 14 days at 4°C indicated no significant effects (p>0.05) due to ultrasonication. In another experiment, post‐chill broiler drumsticks were treated with ultrasonic energy in 1% lactic acid at pH 2 and 4 for 0.5, 2, and 3.5 min. After 0 and 10 days at 4°C there was no significant effect (p>0.05) of ultrasonication on APC.