bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of SDS‐PAGE Method for Estimating Protein Digestibility
Authors: KIM YEOUNG A. , BARBEAU WILLIAM E.
Published: August 2006

In a new technique digestibility of unheated and autoclaved soy protein concentrate (SPC) samples was determined in vitro by SDS‐PAGE. Results were compared with those determined by the pH drop method and with apparent in vivo digestibility in rats. Results of the pH drop method correlated more highly (r = 0.95) with apparent in vivo digestibility than SDS‐PAGE results (r=0.92). However, the SDS‐PAGE technique had two advantages: it allowed estimation of the molecular weight(s) of polypeptides/peptides remaining in protein hydrolyzates and from densitometric analysis, visualization of the process of protein digestion.
Particle Size Effects on the Diffuse Reflectance of a Sucrose‐Caramel Admixture
Authors: SAGUY ISRAEL SAM , GRAF ERNST
Published: August 2006

Decreasing the particle size of homogeneous colorant (caramel) from 68 to 28 microns increased lightness as predicted by the Kubelka‐Munk theory. The presence of diluent (sucrose) reversed particle size effects, i.e., reduced caramel particle size decreased mixture lightness. Decreasing the particle size of the diluent, however, substantially increased the diffuse reflectance of the admixture, lowering its color intensity. The degree of color masking was determined mainly by the particle size of sucrose and to a much lesser extent by that of caramel. The dilution ratio and particle size of both colorant and diluent could be used to control the color of many food systems.
Nitrate Analysis in Meats; Comparison of Two Methods
Authors: SANDERSON JAMES E. , CONSAUL J. ROSS , LEE KEN
Published: August 2006

A high performance liquid chromatographic method (HPLC) was compared to cadmium reduction‐Griess (Cd‐Griess). Nitrate and nitrite were measured in fresh and cured meats. Nitrate levels by HPLC ranged from 6.2 to 26.7 nmol/g in fresh meats and from 124 to 3018 nmol/g in cured meats. Nitrate contents by HPLC were significantly higher (p<0.05) than those by Cd‐Griess. Small amounts of nitrite (0–7.3 nmol/g) were detected in fresh meat samples by Cd‐Griess. Results were similar to those used by the National Academy of Sciences to estimate human exposure to nitrate from fresh meats. Results from HPLC methods may provide more accurate estimates of human exposure to nitrate and nitrite.
Characteristics of Low‐fat Ground Beef Containing Texture‐modifying Ingredients
Authors: TROUTT E.S. , HUNT M.C. , JOHNSON D.E. , CLAUS J.R. , KASTNER C.L. , KROPF D.H.
Published: August 2006

Dietary fibers, starches, and Polydextrose® were incorporated unhydrated into 5 and 10% fat hamburger for texture modification and comparison to 5, 10, 20, and 30% fat controls. Levels for individual and total ingredients ranged from 0.5 to 4% and 3.5 to 6%, respectively. Treatments containing Polydextrose, starch, and fiber had cooking losses 20–40% less than controls. Patties containing three‐way combinations of ingredients were more similar to 20% fat controls for texture traits than were those containing 1 or 2 ingredients: Patties with ingredients had less oily coating of the mouth, but were less juicy than controls. Beef flavor intensity scores were reduced slightly for low‐fat patties with ingredients. Texture modification of low‐fat ground beef is possible with food‐grade ingredients.
pH and Sodium Chloride Effects on Emulsifying Properties of Egg Yolk Phosvitin
Authors: CHUNG SIEW LIAN , FERRIER LES K.
Published: August 2006

The emulsifying properties of phosvitin dissolved in water and 0.1, 0.5 and 1.0 M NaCl were determined from pH 3 to 10. The change in its emulsifying activity (EA) with pH was slight but significant (p<0.05) and emulsion stability (ES) was relatively high (68‐73%), except at pH 5 (17%) and 10 (48%). The EA of phosvitin was higher than that of bovine serum albumin (BSA) at pH 3 or 8 and ES was higher than BSA at all pH levels except at pH 5 and 10. Added NaCl decreased in the EA of phosvitin at pH 3 and 10 and decreased the ES between pH 3 and 9. Increased instability of emulsions resulted mainly in coalescence of oil droplets at NaCl ≥ 0.5M. Salt increased the viscosity of phosvitin emulsion only at pH 3 but not at pH > 5. The viscosities of BSA emulsions were higher than those of phosvitin at pH 3, 5 or 8.
k‐Casein Heterogeneity and Mild Heating Effects on Susceptibility to Chymosin Action
Authors: HAQUE ZAHUR U. , KHALIFA MAHAMMED Y.
Published: August 2006

Bovine SH‐k‐casein (k‐C‐pool) was fractionated into five components based on carbohydrate and sialic acid contents (k‐C‐P1 < k‐C‐P2 < k‐C‐P3 < k‐C‐P4 < k‐C‐P5) by ion‐exchange chromatography (DEAE‐cellulose). Chymosin susceptibility observed by monitoring changes in optical density during enzyme action, varied among the components. This was a reflection of the difference in self‐association of the proteins in aqueous dispersion as determined by hydrophobic interaction chromatograph. There was an inverse relationship between surface hydrophobicity of the protein polymers (k‐C‐P2 >k‐C‐P3 >k‐C‐P4 > k‐C‐P5 > k‐C‐P4 > k‐C‐pool) and their susceptibility to chymosin at 37°C, pH 6.8 (k‐C‐pool >k‐C‐P1 >k‐C‐P5 > k‐C‐P4 > k‐C‐P3 > k‐C‐P2). Mild heating decreased susceptibility and affected flocculation of all except the highly glycosilated components k‐C‐P4 and k‐C‐P5 reflecting amphipathicity imparted thermostability.
Mathematical Model for Water Diffusion During Brining of Hard and Semi‐hard Cheese
Authors: LUNA JULIO A. , CHAVEZ MÓNICA S.
Published: August 2006

The integral method, which is an approximate analytic method, was used to obtain the theoretical profile of moisture changes during brining of cheese. A mass layer was defined in the model where all water variations take place. The model was applied at different times to semi‐hard cheese brining and compared with experimental data. A moisture pseudo diffusion coefficient was obtained from experimental data as part of the proposed model. Agreement was good, which demonstrated the applicability of the model.
Quality Changes of Pond‐raised Hybrid Striped Bass during Chillpack and Refrigerated Storage
Authors: BOYD L.C. , GREEN D.P. , LePORS L.A.
Published: August 2006

Pond‐raised hybrid striped bass were commercially processed into fillets with and without belly flap, packaged in oxygen permeable bags (Cryovac E(tm)), and stored as chillpack samples (‐2°C) and as refrigerated samples (2°C). Quality changes were determined over 21 days storage by microbiological, chemical, and sensory evaluations. Aerobic plate counts and hypoxanthine formation showed evidence of rapid deterioration of refrigerated samples after 8 days storage compared to 21 days for chillpack samples. A trained sensory panel found 21 day stored chillpack samples similar in flavor and aroma but of firmer texture than refrigerated samples stored 8 days. Panelists found no differences between trimmed and whole fillets. Hypoxanthine formation and aerobic plate counts appeared to be good indicators of quality deterioration, whereas thiobarbituric acid measurements were not.
Effect of Frozen Storage on the Gel‐forming Properties of Hoki (Macruronus novaezelandiae)
Authors: MACDONALD GRANT A. , LELIEVRE JOHN , WILSON NEIL D.C.
Published: August 2006

The possibility of using frozen hoki to make surimi was investigated. At intervals, fish were thawed under controlled conditions and gels were then made from minces of the flesh. Both puncture and torsion tests showed the quality of gels declined with duration of storage of frozen hoki. This decline was matched by a decrease in pH and an increase in formaldehyde concentration in the frozen flesh. The data suggest a land‐based surimi plant could not be operated outside the harvesting season to any appreciable extent using frozen hoki stored at ‐29°C.
Influence of Shear Treatments on Consistency and Gelling Properties of Whey Protein Isolate Suspensions
Authors: KER Y.C. , TOLEDO R.T.
Published: August 2006

Suspensions of whey protein isolate (WPI) subjected to controlled shearing by capillary extrusion, and Theologically tested after shearing, showed increasing consistency index as applied shear rate increased. Sheared suspensions gelled more rapidly than unsheared ones and produced stronger gels. SEM micrographs showed the development of a fine fibrous‐like structure in the sheared suspensions, indicating numerous sites of protein‐protein interaction. Sheared WPI suspensions, added as a replacement for fat in frankfurter formulations, showed excellent water‐holding capacity, producing low‐fat frankfurters with elastic moduli in the same order of magnitude as commercial frankfurters.
Soybean Flour/Oil and Wheat Bran Effects on Characteristics of Cassava (Manihot esculenta Crantz) Flour Extrudate
Authors: BADRIE N. , MELLOWES W.A.
Published: August 2006

Adding soybean flour, soybean oil and wheat bran to cassava flour increased the percentage of crude protein/fat and crude fiber respectively in the blends. Crude protein or extrudate correlated negatively (P<0.01) with expansion, water solubility or total reducing sugars and positively (P<0.01) with bulk density, and water absorption. Crude fiber of extrudate correlated negatively (P<0.01) with expansion, bulk density and total reducing sugars. At 4% soybean oil addition, extrudate expansion and WSI were highest, while bulk density and WAI were lowest. Extrudates became more yellow in color on addition of soybean flour.
Cell Size Distributions of Puffed Corn Extrudates
Authors: BARRETT A.M. , PELEG M.
Published: August 2006

The cell size distributions of various experimental puffed corn extrudates were determined by image analysis, applied to longitudinal and transversal cross sections. Individual cell cross‐sectional area was used as the size measure. All the cell size distributions, regardless of specimen orientation, composition and extrusion conditions, were described mathematically by both the log‐normal and Rosin‐Rammler distribution functions. The distributions mean size, degree of skew‐ness or the corresponding distribution functions constants, were characteristic of the extrudate type and its particular cellular structure.
Detection of Color Changes in Green Vegetables
Authors: GNANASEKHARAN V. , SHEWFELT R.L. , CHINNAN M.S.
Published: August 2006

The sensitivity of colorimetry and sensory evaluation for determination of postharvest color changes in broccoli (B), cucumber (C), spinach (S) and tomato (T) was studied at normal (10°C for C and T, 4°C for B and S) and abuse (37°C for C and T, 21°C for B and S) temperatures. Both techniques resolved major color changes but failed to detect changes under normal storage temperatures. With significant color changes, both methods exhibited similar patterns. The sensitivity of detection of color changes in green vegetables should be determined before measuring such changes during storage.
Pilot Study of Cucumber Fermentation: Diffusing Gases and Bloater Damage
Authors: RODRIGO M. , LAZARO M.J. , GARCIA G. , CONESA F. , SAFON J.
Published: August 2006

A pilot study was made of the effect of temperature (17 and 26°C) and purging, with nitrogen (5‐20 L/hr applied continuously and intermittently) or air (20 L/hr for 7 hr/day), o n the development of fermentation and on the incidence of bloater damage in cucumbers. Temperature affected the rate of fermentation and both temperature and purging strongly affected the incidence of bloater damage. At 17°C purging was not necessary, and at 26°C 10 L/hr was sufficient, applied for 7 hr/day for 7 days.
Computer‐aided Optimization of Wine Blending
Authors: DATTA S. , NAKAI S.
Published: August 2006

An objective method was developed to blend wines for standardizing flavor quality. Aroma volatiles of varietal and white stock wines, and the target wine were analyzed by equilibrium gas headspace chromatography. Similarity of the aroma profiles of the varietal and stock wines to the target wine was calculated from GC peak areas. The simplex optimization program carried out computational bleeding to determine the ratios of the varietal and white stock wines that would be required to simulate the aroma of the target wine. For two blending experiments, the computer optimized blend could not be differentiated from target wine by a sensory taste panel.
Edible Wheat Gluten Films: Influence of the Main Process Variables on Film Properties using Response Surface Methodology
Authors: GONTARD NATHALIE , GUILBERT STÉPHANE , CUQ JEAN‐LOUIS
Published: August 2006

An edible wheat gluten film was developed and effects of gluten concentration, ethanol concentration (ET) and pH of the film‐forming solution on various film properties were evaluated using Response Surface Methodology. pH and ethanol concentration had strong interactive effects on film opacity, water solubility and water vapor permeability. A simultaneous variation of ethanol concentration and pH between 32.5% ET, pH 4 and 45% ET, pH 2 resulted in homogeneous and transparent film with relatively low water solubility. The lowest water vapor permeability would be expected with 20% ethanol concentration and pH 6. Mechanical properties were mainly affected by gluten concentration and pH. The most resistant film was obtained at high gluten concentration (12.5%) and pH 5.
Parametric Analysis for Thawing Frozen Spheroidal (Prolate and Oblate) or Finitely Cylindrical Food
Authors: SHEEN SHIOWSHUH , HAYAKAWA KAN‐ICHI
Published: August 2006

A screening analysis was performed to determine the influence of independent parameters (18) on thawing times of frozen spherical (prolate and oblate) and finitely cylindrical foods using a computerized simulation procedure assuming food volume shrinkage from density changes and temperature dependent physical properties. Of 18 independent parameters, 6 were significant for both foods: thawing medium temperature, initial freezing point, Biot number, radiative heat exchange, a parameter for effective specific heat and shape factor (nonsignificant influence of volumetric changes). Predictive regression equations were developed for estimating thawing time as function of significant parameters. Predictive equations were validated experimentally. A sensitivity analysis showed errors in thawing time were influenced most strongly by food dimensions, followed by operational temperatures, thermophysical properties and convective surface heat‐transfer coefficient.
Sorption Isotherms and Light Stabilities of Aluminum Laked Riboflavin 5′‐Phosphate
Authors: HUANG A. S. , BYERLY D. S.
Published: August 2006

Aluminum oxide was used to insolubilize (i.e. to lake) riboflavin 5′‐phosphate (FMN) to improve the light stability of vitamin B2. HPLC was used to determine adsorption percentage and light stabilities of laked FMN. The adsorption of FMN on aluminum oxide was very effective. An FMN content of 55% in lake was achievable, with adsorption of 91%. The adsorption isotherm was of the Langmuir class, and differed from the desorption isotherm. The stabilities of laked FMN at different light intensities and aw values were significantly (p=0.05) higher than those of free FMN.
Identification of Staphylococci and Micrococci Isolated from an Intermediate Moisture Meat Product
Authors: KOTZEKIDOU P.
Published: August 2006

The identification of staphylococci and micrococci isolated from an intermediate moisture meat product, basturma, was studied. From the 120 isolates 92.5% were classified as staphylococci and 7.5% as micrococci. The differentiation of the species revealed: 42%Staphylococcus epidermidis, 32%Staphylococcus saprophyticus, 12%Staphylococcus simulans, 4%Staphylococcus carnosus, 2% Staphylococcus hyicus subsp. hyicus and 7.5%Micrococcus varians.
Suppression of Thermal Denaturation of Myosin Subfragment‐1 of Alaska Pollack (Theragra chalcogramma) by Sorbitol and Accelerated Inactivation by Pyrophosphate
Authors: KONNO KUNIHIKO
Published: August 2006

Thermal denaturation of myosin subfragment‐1 (S‐1), prepared from myofibrils (Mf) of Alaska pollack dorsal muscle by chymotryptic digestion, was well suppressed by sorbitol addition in a concentration dependent relationship. ATP and ADP also suppressed the ATPase inactivation significantly at different degrees. On the contrary, pyrophosphate (PPi) accelerated the inactivation by several‐fold; half the maximal acceleration occurred at about 30 μn, M PPi concentration. The accelerated inactivation by PPi addition was remarkable at high‐salt medium such as 0.5M KC1.
Lysosomal Enzyme Effects on the Postmortem Changes in Tilapia (Tilapia nilotica X T. aurea) Muscle Myofibrils
Authors: JIANG SHANN‐TZONG , WANG YUH‐TAI , CHEN CHING‐SAN
Published: August 2006

To investigate the effects of lysosomal proteases on myofibril fragmentation, tilapia (Tilapia nilotica X T. aurea) muscle myofibrils were incubated with isolated lysosomal fraction containing 12 units of cathepsin D/mL (G‐II) and pure cathepsin D (12 units/mL G‐III) at pH 5.5, 6.0, and 6.5 for 3 days at 4°C. Among samples incubated at pH 5.5, the degree of myofibril fragmentation (DMF) of G‐III was highest, while, at pH 6.0 and 6.5, that of G‐II was highest. At pH 6.5, the higher DMF of G‐III than that of G‐I suggested that cathepsin D still had proteolytic activity on myofibrils. Difference in the decrease of protein content between G‐III and G‐I, and between G‐II and G‐I indicated that proteolysis caused by cathepsin D was highest at pH 5.5, while that caused by lysosomal enzymes was highest at pH 6.5. This suggested the participation of lysosomal enzymes in the fragmentation of myofibrils.
Microbial and Chemical Analysis of Chihuahua Cheese and Relationship to Histamine and Tyramine
Authors: DIAZ‐CINCO M.E. , FRAIJO O. , GRAJEDA P. , LOZANO‐TAYLOR J. , DE MEJÍA E. GONZALEZ
Published: August 2006

Freshly made Mexican white cheese, “Queso Chihuahua,” obtained in Chihuahua and Hermosillo, Mexico, was analyzed. An initial representative sample was taken to determine microbial quality, chemical composition and amine content. The remainder was cut into portions and randomized for storage at 5 or 25°C. Representative samples were taken at 4, 8 and 12 days for analysis. Chihuahua cheese contained 43.7% fat, 49.2% protein, 2.7% salt, and 45% moisture. Water activity was 0.95 and pH 5.25. No pathogens were isolated. However, aerophilic plate count and coliforms exceeded permissible levels. Initially, amines were low, but increased during storage as proteolysis occurred. PH, salt and protein had the greatest influence on amine production.
Chemical, Physical and Sensory Characteristics of Peanut Milk as Affected by Processing Conditions
Authors: LEE CHAN , BEUCHAT LARRY R.
Published: August 2006

The influence of processing conditions on chemical, physical and sensory characteristics of aqueous extracts of peanuts (peanut milk) prepared for lactic bacterial fermentation was investigated. Soaking peanuts in 1.0% NaHCO3 before extraction resulted in a lighter colored milk, and homogenization enhanced lightness. Cooking peanuts before grinding reduced total solids and protein contents of milk. Hexanal concentration was greatly reduced by cooking peanuts for 10 min. The most satisfactory conditions for preparing peanut milk consisted of soaking peanuts in 0.5% NaHCO3, cooking for 10 min and homogenizing the extract at 4000 psi.
Characteristics and Functional Properties of Protein Isolates from Various Peanut (Arachis hypogaea L.) Cultivars
Authors: KIM NAMSOO , KIM YOUNG JIN , NAM YOUNG JUNG
Published: August 2006

Protein isolates from 9 cultivars of peanut (Arachis hypogaea L.) were compared. Sephadex G‐200 gel filtration and nondenaturing polyacrylamide gel electrophoresis (NPAGE) of the protein isolates showed very similar patterns of arachin and nonarachin fractions. The content of individual fractions was somewhat different among cultivars, possibly indicating genetic variability. Sodium dodecyl sulfate‐PAGE (SDS‐PAGE) showed that the protein isolates had extremely complex sub‐unit compositions. The content of acidic amino acids of the protein isolates was 34–38%, basic was 15–17%. Differences in some functionalities such as solubility and emulsification activity were conspicuous among cultivars.
Fractionation of Soy Protein Hydrolysates using Ultrafiltration Membranes
Authors: DEESLIE W. DAVID , CHERYAN MUNIR
Published: August 2006

The effect of membrane pore size on the molecular weight distribution and selected functional properties of a protein hydrolysate produced from soy isolate and Pronase was examined. Molecular weight distributions were similar for permeates from 5000, 10,000 and 50,000 molecular weight cut‐off (MWCO) membranes: two large fractions at 2300 and 1000 daltons. The 100,000 MWCO membrane resulted in three fractions of 25,000, 13,000 and 2300 daltons. Solubility of the hydrolysate increased with decrease in MWCO, while foam stability decreased.
Extraction of Triglycerides and Phospholipids from Canola with Supercritical Carbon Dioxide and Ethanol
Authors: TEMELLI FERAL
Published: August 2006

Phospholipids used as emulsifiers were sparingly soluble in supercritical CO2 (SC‐CO2), but could be recovered with the addition of ethanol as an entrainer. Triglycerides and lipids containing phospholipids were extracted with SC‐CO2 in two subsequent steps from both canola flakes and press cake containing 0 and 5% ethanol, respectively. 70°C, 62.0 MPa and addition of ethanol at an initial level of 5% gave maximum yield of lipids. TLC showed the presence of phospholipids in SC‐CO2‐ethanol extracts. SC‐CO2 extracts of flakes did not contain long chain fatty acids (C20:0, C22:0, C22:1), but they were extracted when ethanol was added to flakes and when press cake was the raw material.
Sugar and Soluble Solids Changes in Refrigerated Sweet Corn (Zea mays L)
Authors: ZHU S. , MOUNT J. R. , COLLINS J. L.
Published: August 2006

Three sweet corn (Zea mays L) genotypes, one cultivar each, were tested for sugar and soluble solids changes at 6°C for 5 days. Genotypes and cultivars were sugary (su), ‘Silver Queen’; sugary enhanced (se), ‘Incredible’ and super sweet (sh 2), ‘How Sweet It Is.’ Fructose, glucose, sucrose, maltose, total sugars and °Brix were measured. Sucrose predominated. Generally, °Brix, fructose, glucose and sucrose decreased and maltose increased, sh 2 had lowest °Brix and highest sucrose and total sugars, and su had highest °Brix and lowest sucrose and total sugars, su consisted of 3.8% total sugars (DWB); se, 7.2% and sh 2, 10.9%. Overall correlation coefficient between °Brix and total sugars was −0.99.
Mushroom (Agaricus bisporus), Its Polyphenoloxidase, and Polyphenolics Affect In Vitro Iron Availability
Authors: Da DAMIO PAUL A. , THOMPSON DONALD B.
Published: August 2006

In vitro iron availability (IA) from egg white meals was 14–17% of total meal iron. When mushroom (Agaricus bisporus) was added to egg white meals, IA decreased. The initially low IA from whey protein concentrate meals (<1% of meal iron) was enhanced by mushroom. Sodium benzoate or sodium bisulfite added to egg white/ mushroom meals increased IA. Addition of polyphenoloxidase (PPO) and gallic acid to egg white meals decreased IA; however, gallic acid alone increased IA. Blanching mushrooms eliminated PPO activity and increased IA of egg white/mushroom meals, but it was still less than for egg white meals. Sodium bisulfite added to blanched mushroom/egg white meals increased IA above that for egg white meals. Results are consistent with the interpretation that enzymatic browning can decrease IA.
Two Dimensional Simultaneous Heat and Moisture Transfer in Composite Food
Authors: SAKAI NOBORU , HAYAKAWA KAN‐ICHI
Published: August 2006

A computerized method was developed to predict two dimensional, simultaneous heat and moisture transfer in a composite food with chemical reactions, based on the use of the chemical potential as the mass transfer potential. Thermodynamically interactive heat and mass fluxes were included in the mathematical model. Composite cylindrical samples in three layers prepared from a high amylose starch granule hydrate and a mixture of the same dhydrate and sucrose were dried in a forced air dryer to experimentally verify values predicted by the computerized method. The central temperatures and average moisture contents of the samples determined experimentally, agreed well with those predicted theoretically.
Available Lysine in Protein, Assay Using o‐Phthalaldehyde/ N‐Acetyl‐L‐cysteine Spectrophotometric Method
Authors: HERNANDEZ M.J. MEDINA , ALVAREZ‐COQUE M.C. GARCIA
Published: August 2006

An assay was based on reaction of free ε‐amino groups in proteins with the o‐phthalaldehyde/N‐acetyl‐L‐cysteine reagent to form isoindoles, which absorb at 335 nm. The procedure was suitable for proteins or mixtures of proteins with available lysine contents of more than 5 moles lysine/mole protein and required absence of free amino acids and peptides. This method was simpler and more convenient than other methods, since it did not require hydrolysis, amino acid analysis, long heating periods or solvent extraction.
Visual and Spectrophotometric Evaluations of Beef Color Stability
Authors: ARNOLD R.N. , SCHELLER K.K. , ARP S.C. , WILLIAMS S.N. , SCHAEFER D.M.
Published: August 2006

Slices of longissimus and gluteus medius muscles from 96 beef steers were displayed under simulated retail display conditions. Meat color display life was calculated by methods termed (1) change between days and (2) days to threshold. The days to threshold approach yielded estimates of color display life which were more consistent among slaughter groups of steers and within muscles. Longissimus had a longer color display life than gluteus medius. Reflectance measurements of beef color provided similar relative estimates of color display life as visual assessment. The accumulation of metmyoglobin at the onset of discoloration was associated with variances which were more homogeneous than those for percentage discoloration determined by visual assessment.
Infiltrated Biopolymers Effect on Quality of Dehydrated Carrots
Authors: MUDAHAR GURMAIL S. , BUHR R. JEFFREY , JEN JOSEPH J.
Published: August 2006

The penetration pattern of biopolymers in plant tissue during processing was studied. Carrot dices were infused with dye‐dextran standards of different molecular weights (T10, T40, T70 and T500). Polymers of smaller size were found within the intercellular spaces and the cell walls. Larger polymers were found only in broken cells near the surface of the tissue. Biopolymers of small size were theorized to provide strength to the cell wall of plant tissue and assist in maintaining cellular integrity during dehydration. This was further verified in that the dextrans of molecular weight of 10,000 produced best quality dehydrated carrots with high rehydration ratio, more retention of carotenoids and high water‐holding capacity.
Hydroxymethylfurfural Accumulation in Applesauce Packaged in Multilayer Polymer Films and Glass
Authors: FERNANDES L. I. , McLELLAN M. R.
Published: August 2006

Applesauce packaged in four different multilayer polymer films and glass was evaluated for changes in hydroxymethylfurfural content during storage. Packages were held for 15 wk at 20°, 30°, 37° and 43°C. Hydroxymethyfurfural content was measured by HPLC analysis every 5 weeks. For all package types more HMF was measured at higher storage temperatures as expected, however, total amounts of HMF also varied according to package type. Comparison of HMF across . package types as an index of thermal history would be of questionable value.
Microbial and Oxidative Changes in Low‐Fat Ground Beef During Simulated Retail Distribution
Authors: EGBERT W.R. , HUFFMAN D.L. , CHEN C.M. , JONES W.R.
Published: August 2006

A low‐fat ground beef product containing water, carrageenan, encapsulated salt and hydrolyzed vegetable protein (carrageenan‐based) was compared to a low‐fat, all‐beef control during simulated commercial manufacturing and retail distribution. Few differences were found in oxidative stability and microbial growth of the two. No differences (P>0.05) were found in aerobic plate counts, populations of psychrotrophs or mold and yeast populations for the two products. Hunter color ‘a’ values (redness) and overall color scores for surface color were higher (P<0.05) for the carrageenan‐based product than the all‐beef product. Retail display of low‐fat products in aerobic packaging resulted in greater (P<0.05) product discoloration than anaerobic retail display.
Volatile Concentration and Flavor of Beef as Influenced by Diet
Authors: MARURI J. L. , LARICK D. K.
Published: August 2006

Yearling steers (48) were finished on one of three intense pasture rotation systems: (1) Tifleaf pearl millet; (2) millet with restricted grain; or (3) millet followed by grain ad libitum in the feedlot. In both 20% fat ground beef and subcutaneous fat, gamey/stale off‐flavor decreased and roasted beef flavor increased when steers were fed grain. Compounds (59) including acids, alcohols, aldehydes, diterpenoids, hydrocarbons, and lactones, were identified in the purge‐and‐trap volatiles. Lactones positively correlated with roasted beef flavor and negatively correlated with gamey/stale off‐flavor, whereas diterpenoids positively correlated with gamey/stale off‐flavor and negatively correlated with roasted beef flavor.
Physical, Chemical and Sensory Changes in Irradiated Fresh Pork Packaged in Modified Atmosphere
Authors: LAMBERT ANNE D. , SMITH JAMES P. , DODDS KAREN L.
Published: August 2006

The effects of irradiation dose (0, 0.5 and 1.0 kGy), headspace oxygen (0, 10 and 20% O2, balance nitrogen) and storage temperature (5, 15 and 25°C) on the physical, chemical and sensory changes in fresh pork were studied using factorial design experiments. Irradiation in the absence of oxygen extended the sensory shelf life of pork from 9 to 26 days at 5°C and from & lt; 2 to 2 days at 25°C. Oxygen in the package headspace combined with irradiation adversely affected physical, chemical and sensory characteristics of the end product.
Thermal Aggregation Properties of Duck Salt‐Soluble Proteins at Selected pH Values
Authors: NDI EMBOLA E. , BREKKE CLARK J.
Published: August 2006

Thermal aggregation properties of duck breast and leg salt‐soluble proteins (SSP) were studied at pH 5.50, 5.75 and 6.00. At pH 5.50, a major transition for breast was observed at 60.3°C and for leg at 41.8°C. At pH 5.75, major transitions at 44.6 and 43.2°C were obtained, respectively, for the breast and leg SSP. Three transitions at 46.0, 53.0 and 59.0°C were exhibited by breast SSP at pH 6.00, whereas only two major transitions at 47.4 and 54.0°C were identified in leg SSP. Changes in transition peak heights and shifts in transition temperatures as a result of pH changes indicated that, depending on fiber type, pH may enhance or suppress the aggregation behavior of specific constituents of the myosin/actomyosin complex, thereby altering the overall aggregation pattern of the protein preparation.
Metallic Cations Affect Functional Performance of Spray‐Dried Heat‐Treated Egg White
Authors: COTTERILL O. J. , CHANG C. C. , McBEE L. E. , HEYMANN H.
Published: August 2006

The functional performance of four metallic cations (Cu++, Al+++, Fe+++, Zn++) in spray‐dried, heat‐treated egg white were evaluated. Cu++ excelled in all functional categories involving foams and angel food cakes. Zn++ was least effective. These data suggest that Cu++ would be a suitable additive to spray‐dried egg white systems.
Vacuum Packaging, Ascorbic Acid and Frozen Storage Effects on Heme and Nonheme Iron Content of Mackerel
Authors: GOMEZ‐BASAURI J. V. , REGENSTEIN J. M.
Published: August 2006

Vacuum packaging and ascorbic acid were tested for their ability to prevent heme iron loss in mackerel (Scomber scombrus). Vacuum packed samples had less heme breakdown than air packed samples at frozen storage temperatures above −20°C. Ascorbic acid protected the heme at all temperatures when compared to air or vacuum packed samples.
Biochemical Characterization of a Low Trypsin Inhibitor Soybean
Authors: McNIVEN M.A. , GRIMMELT B. , MacLEOD J.A. , VOLDENG HARVEY
Published: August 2006

A low trypsin inhibitor soybean (LTI) was characterized using electrophoresis, enzyme activity measurements, and gel exclusion chromatography. The protein profiles were similar to a control soybean. Gel exclusion chromatography resulted in two peaks of trypsin inhibitor activity in the control. The first peak, absent in LTI, proved to be Kunitz trypsin inhibitor and was electrophoretically isomorphic. The second inhibitor consisted of at least five isotypes and co‐eluted with Bowman‐Birk trypsin inhibitor. Shorter heating times were required to inactivate both trypsin and chymotrypsin inhibitor activity in LTI compared to control soybeans. The use of LTI may increase the economic viability of soybeans as protein supplements for humans.
Kiwifruit Lipoxygenase: Preparation and Characteristics
Authors: BOYES STEWART , PERERA CONRAD , YOUNG HARRY
Published: August 2006

Kiwifruit were analyzed for the presence of lipoxygenase (LOX) after mass‐spectrophotometric analysis of kiwifruit pulp showed the presence of hexanal and hex‐2‐enal, considered to be break‐down products of the reaction initiated by LOX. A spectrophotometric assay showed high levels of LOX when compared to other fruits and vegetables. Kiwifruit have at least one isoenzyme belonging to the class II group of LOX iso‐enzymes, similar to those identified in asparagus, cucumber, tomato and apple. The LOX required detergent‐solubilization and was partially purified. Relative to other known lipoxygenases kiwifruit LOX is heat‐stable. It catalysed the hydroperoxidation of free fatty acids but not trilinolein.
Texturization of Sweetened Mango Pulp: Optimization using Response Surface Methodology
Authors: MOUQUET CLAIRE , DUMAS JEAN‐CLAUDE , GUILBERT STEPHANE
Published: August 2006

Sugar added mango pulp was texturized with alginate. To optimize both the mechanical properties and thermostability of the products, an experimental design was used combined with response surface methodology. Alginate concentration was the major factor affecting mechanical properties of texturized pieces with higher strength as the gelling agent concentration increased. Furthermore, gel strength and thermostability generally increased as calcium and glucono‐δ‐lactone concentrations, and/or heat treatment duration increased. As large quantities of sweetened pulp were used, texturized pieces with high dry matter content and good flavor qualities were obtained.
Water Vapor Adsorption Isotherms of Guava, Mango and Pineapple
Authors: HUBINGER M. , MENEGALLI F. C. , AGUERRE R. J. , SUAREZ C.
Published: August 2006

Isotherms were determined at 25° and 50°C, using an electronic water activity meter. For the 3 fruits temperature had practically no effect on the isotherms. Sorption capacity of freeze‐dried pineapple was higher than that for vacuum dried. The higher sorption capacity of mango and pineapple in comparison to guava corresponded to the respective sugar contents of the fruits.
Compositional Changes in Brewed Coffee as a Function of Brewing Time
Authors: LEE TERRENCE A. , KEMPTHORNE REBECCA , HARDY JAMES K.
Published: August 2006

Variations in the composition of brewed coffee as a function of brewing time were monitored using gas chromatography‐mass spectrometry. Batches of coffee were produced using flow rates of 50‐500 mL/min, which resulted in brewtimes of 4.42‐31.07 min. While most components increased in concentration with longer brewing times, several showed significant losses beyond 8 min, indicating an optimum brewtime of 7‐9 min.
Amino Acid Metabolism by Yeasts and Lactic Acid Bacteria during Bread Dough Fermentation
Authors: COLLAR CONCEPCIÓN , MASCARÓS ARTURO F. , DE BARBER CARMEN BENEDITO
Published: August 2006

Metabolism of 22 free amino acids (AA) during fermentation(early and later steps) of wheat dough samples started with pure and associated cultures of yeast and lactic acid bacteria, and commercial compressed yeast (CY) were investigated. Unfermented and fermented straight doughs were studied byReversed‐Phase HPLC of their dansyl derivatives. Used as starters were strains of Saccharomyces cervisiae, Lactobacillus brevis, Lactobacillus plantarum and Enterococcus faecium. Statistical data analysis indicated clustering of samples with yeast and samples without yeast (including uninoculated doughs) respectively, based on rate of metabolism of acidiC., basiC., aliphatic and aromatic A A. Differences in AA metabolism during the later fermentation step (DF2) categorized bacterial starters into groups according to balance between degree of assimilation(D F2<0) and exoproteolytic release(DF2>0) of amino acids.
Retrogradation Behavior of Wheat Starch Gels with Differing Molecular Profiles
Authors: ZHANG W. , JACKSON D. S.
Published: August 2006

Differing molecular profiles of starches were developed by acid treatment of native wheat starch. Molecular weight distribution, branching, and linear chain length distribution was characterized. Starches with fewer large size amylopectin fragments, increased smaller size amylopectin fragments, decreased branch points, decreased overall sizes, and narrower linear chain length distributions, had higher initial retrogradation rates. However, all aged starch gels had similar final crystalline enthalpy levels. Different retrogradation behaviors were due to smaller size amylopectin fragments, narrowed linear chain length distribution, and decreased branching. Retrogradation behavior was modeled using classical Avrami kinetics to allow comparison with other retrogradation studies.
Gelling Characteristics of Pectin From Sunflower Head Residues
Authors: CHANG K.C. , MIYAMOTO A.
Published: August 2006

Gelling properties of sunflower head pectin were studied using two instrumental methods: the standard sag method and the Instron textural profile method. For the Instron method, the jellies were formulated with 0‐60% sugar content with various amounts of calcium chloride (30 to 90 mg/g pectin) at pHs 5.4 and 6.0. Sunflower pectin had a gel power of 110 compared to 100 for a citrus low‐methoxyl pectin and 120 for an amidated low‐methoxyl pectin. Sunflower pectin formed jellies under all experimental conditions. Sunflower pectin has a high potential for producing low‐caloric foods, particularly when a near‐neutral taste is required.
Muscle Washing and Raw Material Source Affect Quality and Physicochemical Properties of Low‐salt, Low‐fat, Restructured Beef
Authors: KENNEY P. B. , KASTNER C. L. , KROPF D. H.
Published: August 2006

Five percent unwashed and washed skeletal (USM and WSM) and cardiac (UCM and WCM) muscle and fish surimi (FS) were evaluated in precooked (64.4 °C), restructured beef using 0.2% NaCl. Additionally, a 0.2% NaCl product without binder and a 1.0% NaCl treatment containing 5% USM were made. Washing enhanced sensory and instrumental texture measures of products containing CM but did not affect products containing SM. UCM and WCM appeared beneficial for maintenance of product color but tended to increase lipid oxidation. Washing reduced surface hydrophobicity, decreased disulfide content of CM, increased free sulfhydryls of CM and SM, and lowered soluble protein in binder extracts. Binders did not improve product characteristics.
Thermally Induced Interactions and Gelation of Combined Myofibrillar Protein from White and Red Broiler Muscles
Authors: XIONG Y.OULING L.
Published: August 2006

The gelling properties of broiler myofibrillar protein were studied by determining protein‐protein interactions during heating. Breast and leg salt‐soluble protein (SSP) showed 1–3 transitions in protein‐protein interactions within pH 5.5–6.5. The maximum transition temperatures of leg SSP decreased when leg SSP was mixed with breast SSP. The combined breast/leg myofibrils formed stronger gels than leg myofibrils alone at pH ≥ 6.0, and stronger gels than breast myofibrils alone at pH < 6.0. The results suggest that interactions existed between breast and leg myofibrillar proteins, and the transitions in these interactions were useful for predicting gel strength of the combined breast/ leg myofibrils.
Destruction of Salmonella typhimurium on Chicken Wings by Gamma Radiation
Authors: THAYER D.ONALD W. , DICKERSON C.ATHLEEN Y. , RAO D. RAMKISHAN. , BOYD G.LENN , CHAWAN C.HANDRAMOHAN B.
Published: August 2006

No viable CFU of a streptomycin‐resistant S. typhimurium were detected on chicken wings inoculated with 100 CFU and treated with 1.8 kGy or greater doses of gamma radiation at 5°C in air. The inoculated S. typhimurium did not recover from radiation injury during 3 days of refrigerated storage. Viable CFU were detected on wings inoculated with 1,000 or 10,000 CFU and irradiated with 1.8 kGy but not on those irradiated with 2.7 or greater kGy. The indigenous aerobic mesophilic population on the wings was reduced from 104 to 44 CFU/cm2 by 1.4 kGy.
Physicochemical and Dynamic Properties of Caseins Modified by Chemical Phosphorylation
Authors: MEDINA A. L. , COLAS B. , LE MESTE M. , RENAUDET I. , LORIENT D.
Published: August 2006

Chemical phosphorylation of bovine caseins may be useful for changing their physicochemical properties. Depending on the pH of phosphorylation of caseins by phosphorus oxychloride (POCl3), covalent bonds between phosphate groups and different specific amino acids were formed. After casein phosphorylation, intermolecular associations may occur, as shown by electrophoresis. The solubility of modified casein was increased near the isoelectric point (pHi) and decreased at alkaline and acidic pH. In the presence of Ca++ at alkaline pH, the solubility of phosphorylated casein was lower than that of the control. Rheological parameters appeared to be efficient indices of structural changes occurring in proteins as a result of chemical modifications. Electron spin resonance studies showed that the flexibility of phosphorylated casein was higher than that of the control.
Immunoglobulins from Egg Yolk: Isolation and Purification
Authors: AKITA E. M. , NAKAI S.
Published: August 2006

Simple water dilution was employed for the separation of water‐soluble plasma proteins from egg yolk granules. An optimum recovery of immunoglobulin Y (IgY, 93–96%) in water‐soluble fraction was obtained by sixfold water dilution at pH between 5.0–5.2 with incubation time of 6 hr at 4°C. Among the factors studied, pH was found to be the most important factor affecting IgY recovery. Active IgY of high purity with good recovery was obtained by a combination of several techniques including salt precipitation, alcohol precipitation, ultrafiltration, gel filtration and ion exchange chromatography. Salt precipitation, ultrafiltration, and get filtration is the recommended sequence. Over 100 mg of electrophoretically pure IgY was routinely obtained from one egg.
Thermally Induced Epitope Regions of Ovalbumin Identified with Monoclonal Antibodies
Authors: IKURA K.OJI , HIGASHIGUCHI F.UMIHARU , KITABATAKE N.AOFUMI , DOI E.TSUSHIRO , NARITA H.IROSHI , SASAKI R.YUZO
Published: August 2006

To identify the structural regions of the ovalbumin molecule that change during heat denaturation, we used monoclonal antibodies that reacted specifically with the soluble heat‐denatured ovalbumin as probes. Five monoclonal antibodies recognizing different epitopes of the denatured ovalbumin were produced. Through the isolation and sequence analysis of the peptides derived from ovalbumin that reacted with the monoclonal antibodies, five parts of the ovalbumin molecule were identified as the regions that change structurally and provide new epitopes during heat denaturation. These findings could be useful information in understanding the structural properties of heat‐denatured ovalbumin.
Ineffectiveness of a Fluorometric Method for Identifying Irradiated Food Based on Thymine Glycol
Authors: EWING D.ONALD D. , STEPANIK T.ERENCE M.
Published: August 2006

At dosages used for food irradiation, some of the thymine present in the DNA of irradiated food may be converted to thymine glycol. A fluorometric assay for thymine glycol was investigated as a possible method of detecting irradiated foods based on this effect. Experiments were performed on homogenates of irradiated chicken breast meat and on DNA isolated from irradiated chicken breast meat. In both cases the assay was subject to interference from one of the reagents, o‐aminobenzaldehyde, and lacked the necessary sensitivity to detect the thymine glycol produced by radiolysis of the DNA at relevant dosages.
1‐Octen‐3‐ol in the Cultivated Mushroom, Agaricus bisporus
Authors: MAU J.ENG‐LEUN , BEELMAN R.OBERT B. , ZIEGLER G.REGORY R.
Published: August 2006

Enzymatic formation of l‐octen‐3‐ol in the cultivated mushroom, Agaricus bisporus, was studied. The optimal activity of lipoxygenase‐hydroperoxide lyase enzymes for l‐octen‐3‐ol formation was observed over the pH range 5.0 to 7.0. The highest amount of l‐octen‐3‐ol was produced at pH 6.0. During the crop cycle, the l‐octen‐3‐ol content of mushrooms varied from 19.3 to 37.2 ppm. More l‐octen‐3‐ol was produced in the gills than other morphological tissues. During post‐harvest storage at 12°C, enzyme activity as well as l‐octen‐3‐ol content decreased dramatically over time.
Factors Influencing Serum Separation of Tomato Ketchup
Authors: STOFOROS N.IKOLAOS G. , REID D.AVID S.
Published: August 2006

The effect of tomato cultivar, breaking procedure, starting tomato paste concentration, reconstituted paste, homogenization treatment, percent total and water insoluble solids, and pH on serum separation of tomato ketchup was investigated. Homogenization, as well as increasing the total and/or the water insoluble solids of the ketchup reduced separation. Increasing the total solids of the starting tomato paste decreased the rate of separation, but increased the final amount of serum loss from the resulting ketchup. Among tomato cultivars and breaking procedures included in this study, the Peto 98 cultivar (high water insoluble solids content) and the medium break procedure (at 107.2°C after a 10 min hold at room temperature) gave ketchups with the least serum separation.
Emulsifying Capacity and Emulsion Stability of Soy Proteins Compared with Corn Germ Protein Flour
Authors: WANG C.R. , ZAYAS J.F.
Published: August 2006

Both 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.
Compositional Influence on the pH of Reduced‐Moisture Solutions
Authors: BELL L.EONARD N. , LABUZA T.HEODORE P.
Published: August 2006

The pH of reduced‐moisture systems is not the same as in hydrated systems. As aqueous phosphate buffer solutions become concentrated, the pH of the system decreases. The pH of citrate buffer solutions decreases, then increases as the concentration increases. Identical buffer solutions whose water activity is reduced by the addition of nonionic solutes indicate no correlation of pH with either the water activity reduction or the change in dielectric constant. The response of pH to added solutes appears to be dependent on the chemical nature of the solute and its interaction with water. This study also confirmed the limitations of several theoretical models of ionic activities.
Filtration of Soy Sauce by Ceramic Membrane
Authors: TIEN C.HIN JEN. , CHIANG B.EEN HUANG.
Published: August 2006

Ceramic membrane was used for clarifying soy sauce. The raw soy sauce was cooked, large particles removed by sedimentation, and the supernatant filtered through a 0.2 μm ceramic membrane. At 861 L/hr feed rate, 11 bar operating pressure, and 25°C, the cooked soy sauce was filtered to a permeate/retentate ratio of 2, while maintaining a permeate flux of approximately 15 L/hr.m2. Ceramic membrane filtration did not alter the general composition of soy sauce, but significantly reduced turbidity and count of aerobic microorganisms in the product.