bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling the Contribution of Sugars, Ascorbic Acid, Chlorogenic Acid and Amino Acids to Non‐enzymatic Browning of Potato Chips
Authors: RODRIGUEZ‐SAONA LUIS E. , WROLSTAD RONALD E. , PEREIRA CLIFF
Published: July 2006

The contribution of potato constituents to color development in fried chips was evaluated using model systems. Soluble constituents of potato slices were removed using water and ethanol. Leached slices were infiltrated with pH 6.2 solutions containing sucrose, reducing sugars (glucose and fructose), ascorbic, chlorogenic and amino acids (asparagine and glutamine) in quantities typical for potatoes. Infiltrated slice composition was evaluated by HPLC. Slices were fried and the color measured. Reducing sugars showed linear association with L* and hue angle and quadratic relationship with chroma of chips. Ascorbic acid affected chip color at low reducing sugar levels (40 mg/100g tuber); sucrose also contributed to chip color development.
Sugar and Fat Effects on Sensory Properties of Ice Cream
Authors: GUINARD J.‐X. , ZOUMAS‐MORSE C. , MORI L. , UATONI B. , PANYAM D. , KILARA A.
Published: July 2006

Vanilla ice cream with 8, 13 or 18% sucrose and 10, 14 or 18% butterfat was evaluated by descriptive analysis (DA) with 15 judges, instrumental texture measurements (ITM), and hedonic rating with 146 consumers. Increased sugar caused higher vanilla, almond, buttery, custard/eggy, sweetness, fatty, creamy, doughy and mouthcoating characteristics, and lower coolness, ice crystals, melt rate (ITM) and hardness (ITM). Increased fat caused higher buttery, custard/eggy and sweet flavor, fatty, creamy, doughy and mouthcoating texture, and lower color, ice crystals and melting rate (DA). Acceptability was positively related to the vanilla, creamy, fatty and milky characters, and negatively related to color, ice crystals and ITM hardness.
Oxymyoglobin Oxidation as Affected by Oxidation Products of Phosphatidylcholine Liposomes
Authors: CHAN WENDY K.M. , FAUSTMAN CAMERON , DECKER ERIC A.
Published: July 2006

Supernatants (105,000 ×g) of oxidized phosphatidylcholine (PC) liposomes contained higher levels of thiobarbituric acid‐reactive substances, and caused greater metmyoglobin formation when combined with oxymyoglobin than those of controls (C) or PC plus tocopherol (PCT) (P<0.05). Products of PC liposome oxidation crossed dialysis membranes (mol wt cut‐off = 500 Dalton) and accelerated the oxidation of oxymyoglobin more than C or PCT (P<0.05). The addition of known oxidation products of oleic acid and linoleic acid, fatty acids typical of PC, accelerated oxymyoglobin oxidation relative to controls (P<0.05). Results demonstrated that oxidation products of PC were prooxidative towards oxymyoglobin.
Covalent Bonding in Pressure‐Induced Fish Protein Gels
Authors: GILLELAND G.M. , LANIER T.C. , HAMANN D.D.
Published: July 2006

Surimi pastes were gelled by pressure, incubation at 25°C, cooking, or their combination. Differential scanning calorimetry and solubility measurements indicated that myosin denaturation and disulfide bond formation occurred during pressure‐induced gelation. Time of pressure treatment had little effect on gel fracture properties. Nondisulfide covalent polymerization of myosin did not appreciably occur during pressure‐induced gelation, but was prevalent in gels incubated at 25°C, even when such incubation followed pressure treatment. That combination treatment increased the stress value of cooked gels more than six times, indicating synergy of pressure with the endogenous enzyme transglutaminase, thought to be responsible for gelation of surimi pastes at 25°C.
Non‐Destructive Determination of Fat and Moisture in Whole Atlantic Salmon by Near‐Infrared Diffuse Spectroscopy
Authors: WOLD JENS PETTER , ISAKSSON TOMAS
Published: July 2006

A near‐infrared spectrometer equipped with an interactance optical fiber probe was used to determine the average crude fat and moisture content in the muscle of whole Atlantic salmon (Salmo salar). The fat contents were 8.8—19.2% and moisture 61.0—70.8%, and fish weight range 1.0—5.7 kg. A partial least square regression including 49 salmon resulted in root mean square error of cross validation of 1.12% fat (R = 0.87) and 0.98% moisture (R = 0.86). Results showed that NIR interactance was a suitable non‐destructive screening method for fat and moisture content in farmed Atlantic salmon.
Rheology of Full‐fat and Low‐fat Cheddar Cheeses as Related to Type of Fat Mimetic
Authors: MA L. , DRAKE M.A. , BARBOSA‐CÁNOVAS G.V. , SWANSON B.G.
Published: July 2006

Cheeses with 60% reduced fat were prepared with three fat mimetics and viscoelasticity was studied. Storage and loss moduli of low‐fat cheeses made with a carbohydrate‐based fat mimetic were greater (p < 0.05) than those of low‐fat cheeses made with two protein‐based fat mimetics or low‐fat control cheese, but smaller (p < 0.05) than the storage and loss moduli of full‐fat cheese. A six‐element Kelvin model properly predicted the creep compliance for the full‐fat cheese and the low‐fat cheeses made with or without fat mimetics. Low‐fat cheese made with a carbohydrate‐based fat mimetic had a network structure more similar to full‐fat cheese than the low‐fat control or samples made with protein‐based fat mimetics.
Tempering of Chocolate in a Scraped Surface Heat Exchanger
Authors: LOISEL C. , KELLER G. , LECQ G. , LAUNAY B. , OLLIVON M.
Published: July 2006

Crystallization of dark chocolate during different tempering processes has been studied in‐situ in a lab‐scale Scraped Surface Heat Exchanger. The linear relationship between torque and viscosity made possible the control of chocolate crystallization during tempering by following torque variations vs. time and converting them to equivalent viscosity values. These variations of equivalent viscosity of chocolate observed during tempering were correlated with temper‐meter measurements which had been related to the content of cocoa butter seeding crystals. A temperature cycle (50‐26.1‐30.5‐33.3°C) enabled preparation of a well‐tempered chocolate stable for ≥30 min at that temperature. It was characterized by a seed crystals content of about 1.15 ± 0.1% of cocoa butter, crystallization temperature of 23.9 ± 0.2°C in the temper‐meter and an equivalent viscosity of 3.0 ± 0.4 Pa.s.
High Hydrostatic Pressure as a Hurdle for Zygosaccharomyces bailii Inactivation
Authors: PALOU E. , LÓPEZ‐MALO A. , BARBOSA‐CÁNOVAS G.V. , WELTI‐CHANES J. , SWANSON B.G.
Published: July 2006

The combined effects of high hydrostatic pressure (HHP, 172, 345, 517 or 689 MPa), duration of HHP treatment (0, 2, 4, or 10 min), water activity (aw 0.98 or 0.95), and potassium sorbate (PS) concentration (0 or 1000 ppm) on Zygosaccharomyces bailii inactivation were evaluated at pH 3.5 and 21°C in laboratory model systems. Inactivation of the initial inoculum (≅ 1.0 times; 105 CFU/mL) occurred when the pressure was 689 MPa regardless of aw PS or duration of treatment. Lower pressure was required for Z. bailii inactivation in the presence of PS.
Reduction of Salmonella Contamination on Chicken Egg Shells by a Peroxidase‐Catalyzed Sanitizer
Authors: KUO F.‐L. , KWON Y.M. , CAREY J.B. , HARGIS B.M. , KRIEG D.P. , RICKE S.C.
Published: July 2006

A peroxidase‐catalyzed compound (PCC) sanitizer was tested to determine its bactericidal activity on Salmonella typhimurium and Salmonella enteritidis inoculated on egg shell surfaces. Eggs with no treatment were compared to those immersed in either deionized distilled water, PCC or 200 ppm chlorine‐treated water for 1, 3 or 5 min. Eggs immersed in PCC or chlorinated water solutions had lower (P < 0.05) S. typhimurium and S. enteritidis populations than those not exposed to treatments. No differences were detected among PCC and chlorine treatments except the S. typhimurium populations from PCC dipped eggs were significantly higher than those from eggs dipped in the chlorinated water for 1 min. Results indicate that PCC has potential as an effective shell egg sanitizer.
Optimizing Acceptability of Chicken Nuggets Containing Fermented Cowpea and Peanut Flours
Authors: PRINYAWIWATKUL W. , MCWATTERS K. H. , BEUCHAT L. R. , PHILLIPS R. D.
Published: July 2006

A mixture design was used to optimize the sensory acceptability (appearance, color, flavor, texture, and overall liking) of chicken nuggets containing flours processed from fermented cowpeas (FCF) and fermented partially defatted peanuts (FPDPF). Flavor and texture acceptability correlated highly with overall liking of nuggets. Products containing 20% FCF or FPDPF alone or in combination were unacceptable. Nuggets containing a mixture of 2.5% FCF and 2.5% FPDPF were as acceptable as the control, with a sweet, chickeny flavor. This suggests market potential for such poultry products.
Optimization of Far Infrared Heat Dehydration of Shrimp Using RSM
Authors: FU WEN‐RONG , LIEN WEI‐RENN
Published: July 2006

The effects of plate and air temperature and plate distance were studied on a plate type far infrared radiation (FIR) drier on drying rate and quality (TBA) of dehydrated shrimp. Experimental design and regression equations were derived by response surface methodology. Effect of plate distance on drying rate was not significant. Drying rate increased monotonically with increasing plate and air temperatures. The maximum TBA value occurred at plate temperature 286°C, air temperature 81°C, and plate to sample distance of 7.9cm. Both high plate with low air temperatures and low plate with high air temperatures resulted in optimum drying rate and quality. The low air temperatures are recommended for energy saving consideration.
Rheology of Stirred Yogurt as Affected by Added Milk Fat, Protein and Hydrocolloids
Authors: KEOGH M.K. , O'KENNEDY B.T.
Published: July 2006

The rheological characterization of stirred yogurt with added milk fat, Na caseinate (or micellar casein) and gelatin (4 Bloom strengths), starch or a xanthan gum/LBG 50:50 mixture was carried out. Dynamic and shear values were measured at 8°C and syneresis at 4°C. Consistency (k* and k) and syneresis were more frequently influenced by the composition variables than the power law factors n* and n and the critical strain γc. The k* ranged from 15.8 to 576 Pa sn*, n* from 0.038 to 0.220, γc from 1.6 to 49.0 10‐3, k from 0.37 to 32.47 Pa sn, n from 0.005 to 0.587, and syneresis from 0.0 to 49.2%.
Vanillin and pH Synergistic Effects on Mold Growth
Authors: LÓPEZ‐MALO A. , ALZAMORA S. M. , ARGAIZ A.
Published: July 2006

The combined effects of pH (3.0–4.0) and vanillin concentration (500–1,000 ppm) on the growth of Aspergillus flavus, A. niger, A. ochraceus and A. parasiticus were evaluated in potato‐dextrose agar adjusted to a water activity 0.98. Mold germination time and radial growth rates (RGR) were significantly affected by the variables (p<0.05). For equal concentration of the antimicrobial the reduction in pH had important effects lowering the RGR. The lag time increased as vanillin concentration increased and pH decreased. The inverse lag times of each mold could be described by second order polynomials.
Lipid Oxidation in Cooked Pork as Affected by Vitamin E, Cooking and Storage Conditions
Authors: KINGSTON E.R. , MONAHAN F.J. , BUCKLEY D.J. , LYNCH P.B.
Published: July 2006

The individual and combined effects of muscle vitamin E level, cooking conditions (duration, temperature and rate) and packaging on lipid oxidation in refrigerated cooked pork were examined. Oxidative stability following cooking was higher in pork with a higher vitamin E level (p<0.01), cooked at a lower cooking temperature (p<0.01), cooked for a shorter time (p<0.01), cooked at a faster cooking rate (p<0.05) or stored in vacuum packs (p<0.01). Significant two‐way and three‐way interactions were observed between the effects of muscle vitamin E level, cooking conditions and packaging on lipid oxidation. Adopting more than one of these approaches to minimize lipid oxidation was more effective than adopting a single approach.
Singlet Oxygen and Ascorbic Acid Effects on Dimethyl Disulfide and Off‐Flavor in Skim Milk Exposed to Light
Authors: JUNG M.Y. , YOON S.H. , LEE H.O. , MIN D.B.
Published: July 2006

The light‐induced off‐flavor and dimethyl disulfide increased as fluorescent light exposure increased from 0,2,4,6, to 8h (p<0.05). Sensory evaluation and identified compounds suggest that dimethyl disulfide was mainly responsible for the light‐induced off‐flavor in skim milk. Dimethyl disulfide was formed by the singlet oxygen oxidation of methionine in milk. Gas chromatographic analysis and sensory evaluation showed that 200,500, and 1000 ppm ascorbic acid, which is a singlet oxygen quencher, lowered the formation of dimethyl disulfide and off‐flavor in skim milk (p<0.05).
Purine Content in Grass Shrimp during Storage as Related to Freshness
Authors: LOU SHYI‐NENG
Published: July 2006

In grass shrimp (Penaeus monodon), the combined total content of the uricogenic bases adenine (Ade) and hypoxanthine (Hyp) decreased gradually during storage. Whether stored at 5°C or at room temperature (22°C), a negative regression of log Ade and a positive regression of the Kp value (Hyp/Ade) were observed. Volatile basic nitrogen (VBN) increased during storage at 5°C and 22°C. Correlations between the content of log Ade and VBN at 5°C and 22°C were –0.9248 (p<0.01) and –0.8139 (p<0.05, while those between the Kp value and VBN were 0.9557 (p<0.001) and 0.8197 (p<0.05), respectively. At the point where the shrimp would remain acceptable, the upper limits of Kp were 1.42 and 1.29 for storage at 5°C and 22°C, respectively; the corresponding lower limits of Ade were 18.72 and 20.42 μmole/g dry wt.
Microstructure of Microcapsules Consisting of Whey Proteins and Carbohydrates
Authors: SHEU T‐Y. , ROSENBERG M.
Published: July 2006

Microstructure was studied on spray‐dried microcapsules with wall systems consisting of mixtures of whey protein isolate (WPI) and maltodextrins (DE 5, 10, 15) or corn syrup solids (DE 24). Structure of microcapsules was appreciably affected by type of carbohydrate and by the WPI‐to‐carbohydrate ratio. The extent of surface indentation was inversely related to the proportion of WPI in the wall system. Ratio of low‐to‐high molecular weight solutes in the wall system affected structure. At a WPI‐to‐carbohydrate ratio of 1:1 or higher, whey proteins improved the surface‐smoothness and decrease surface indentation of maltodextrin‐based microcapsules. Combinations of WPI with high‐DE value carbohydrates were more effective than those with carbohydrates of low DE value in limiting surface‐dents formation.
Corn Syrup Solids and Their Saccharide Fractions Affect Crystallization of Amorphous Sucrose
Authors: GABARRA P. , HARTEL R. W.
Published: July 2006

The effects of corn syrup saccharides on the glass transition (Tg) and crystallization of freeze‐dried sucrose were studied using differential scanning calorimetry. Corn syrup (CS) solids were fractionated into samples with differing ranges and types of glucose polymers. Tg of the sucrose/CS additive mixtures depended on number‐average molecular weight, rather than weight‐average molecular weight, of CS material. Additive levels of 10% and 20% (w/w) of CS solids and their fractions interfered with crystallization of amorphous sucrose, whereas levels 50% prevented crystallization. The mechanism by which CS saccharides interfered with crystallization of amorphous sucrose depended not only on Tg but was also influenced by specific interactions between molecules.
Properties and Utilization of Pork from an Advanced Meat Recovery System
Authors: Calhoun C. M. , Schnell T. D. , Mandigo R. W.
Published: July 2006

Pork trim from an advanced meat recovery system, referred to as pork trim‐finely textured (PTFT), was characterized and compared to 80% lean ground pork (GP) and knife trimmed lean (KT). PTFT (0, 5, 10, 15%) was incorporated into 10% and 20% fat ground pork patties. PTFT had higher total pigment, cholesterol, iron and calcium and lower collagen than GP or KT. Fat content of PTFT was similar to GP and KT. PTFT increased redness and juiciness and decreased hardness, chewiness and cohesiveness of ground pork patties. Addition of up to 15% PTFT caused differences which were perceived as improvements in quality. PTFT can be a replacement for pork trim in ground pork products.
Rheological Properties of Chymosin‐Induced Skim Milk Gels as Affected by Milk Storage Time and Temperature
Authors: Renner‐Nantz J. J. , Shoemaker C. F.
Published: July 2006

Fundamental dynamic rheological tests were used to measure the rigidity (|G*|) and viscoelasticity (tan δ) of gels made from skim milk samples that were (1) never cooled, (2) stored at 4°C, or 3) stored at 4°C and then rewarmed to 25°C. Milk cooled and held at 4°C prior to gel formation produced gels with lower |G*| and higher tan(δ) than fresh milk gels. Chilled milk samples that were rewarmed to 25°C for 16h prior to gel formation produced gels with rheological properties similar to fresh milk gels. The solubilization of β‐casein during cold storage was hypothesized to be the cause of observed differences in gel rheology.
Modeling Respiration of Apple Slices in Modified‐Atmosphere Packages
Authors: Lakakul R. , Beaudry R. M. , Hernandez R. J.
Published: July 2006

Modified‐atmosphere packaging was used to provide respiratory data for apple (Malus xdomestica Borkh.) slices at 0, 5, 10 and 15°C. The maximum rate of O2 uptake increased with increasing temperature. The lowest O2 partial pressure to which fruit could be exposed without fermentation also increased with increasing temperature. A mathematical model of film permeability data characterized the effect of fruit mass, film permeability to O2, activation energy of O2 permeation, temperature, and the film type, area, and thickness on O2 partial pressure for hermetically packaged apple slices. The model identified a minimum (fruit mass filmthickness)/(film area) ratio for apple slices, which would simplify package design calculations.
Corn Masa and Tortillas from Extruded Instant Corn Flour Containing Hydrocolloids and Lime
Authors: Arámbula V.G. , Mauricio S.R.A. , Figueroa C.J.D. , González‐Hernández J. , Ordorica F.C.A.
Published: July 2006

Extruded instant corn flour (EICF) samples with hydrocolloids (gums), such as gum arabic, carboxymethylcellulose (CMC), guar and xanthan and with different concentrations of lime (0.1, 0.2 and 0.3% w/w) were prepared by extrusion. The gums were added before or after thermal processing. The dehydration process followed through the weight loss (WL) in masa, the physicochemical (water absorption capacity (WAC) and WL during cooking) characteristics of masa were optimized to give longer dehydration times and tortillas with good textural (rollability, tensile strength and cutting force) properties. The lowest effective moisture diffusion coefficient (D*) was found in masa samples containing 0.2% (w/w) of lime and 0.5% (w/w) of the xanthan gum added before extrusion. These masas produce tortillas with optimum textural characteristics and highest yields.
Tofu Production from Soybeans or Full‐Fat Soyflakes Using Direct and Indirect Heating Processes
Authors: Moizuddin S. , Harvey G. , Fenton A.M. , Wilson L.A.
Published: July 2006

We compared processing yield, composition, and quality of tofu from soybeans and from full‐fat soyflakes. Tofu was made using a steam‐jacketed kettle and a commercial steam‐injected cooker. Hydration time was 10 min for flakes and 12h for whole beans. Regardless of cultivar, a higher tofu yield was obtained from the steam‐injected cooker system than from the steam‐jacketed kettle system. Utilization of flakes required 62‐‐65% less water during soymilk production. Independent of cultivar, tofu produced from full‐fat soyflakes was lower in fat (26% d.b.) than whole soybean tofu (40% d.b.).
Two‐stage Nested PCR Effectiveness for Direct Detection of Vibrio vulnificus in Natural Samples
Authors: Lee J. Y. , Bang Y. B. , Rhee J. H. , Choi S. H.
Published: July 2006

ABSTRCT

The nested primers designed to amplify a 222‐base pair portion of the hemolysin gene, vvhA, were specific for all V. vulnificus strains tested. The nested PCR amplification, coupled with direct extraction of template DNA, revealed improved sensitivity sufficient for detection of 1 to 10 CFU V. vulnificus in 1 mL of seafood homogenates, and eliminated the need for enrichment culturing. Thereby, the nested PCR method achieved a broader applicability, making it effective for extensive use in identification of the pathogen in natural samples such as raw seafoods, seawater and sediments.
Perception of Heat in Cheese Sauces as Affected by Capsaicin Concentration, Fat Level, Fat Mimetic and Time
Authors: Carden L. A. , Penfield M.P. , Saxton A. M.
Published: July 2006

Perceived heat intensity in cheese sauces with five capsaicin levels, three fat levels and four fat mimetics was studied with time intensity techniques. Heat intensity was not related to fat mimetic. No differences occurred among fat levels at 0.0 and 0.4 ppm capsaicin. At 0.8 ppm capsaicin, maximum and total heat intensities of reduced‐ and low‐fat sauces were equal; both were lower in full‐fat sauces (P<0.001). Low‐fat sauces exhibited greater maximum heat and total intensity than full‐fat at 1.2 ppm capsaicin. At 1.6 ppm capsaicin, low‐fat sauces had greater total intensity than either reduced‐or full‐fat (P<0.05) sauces. At low‐fat levels, lower capsaicin concentrations provided heat equal to higher concentrations in full‐fat cheese sauces.
Tenderization of Beef with Pineapple Juice Monitored by Fourier Transform Infrared Spectroscopy and Chemometric Analysis
Authors: Iizuka K. , Aishima T.
Published: July 2006

For nondestructive monitoring of meat tenderizing processes, factor analysis, and evolving factor analysis (EFA) were applied to successively collected attenuated total reflectance‐infrared spectra of beef after treatment with pineapple juice. Absorption around 1600 to 1500 cm−1 and 1400 cm−1 regions increased with time. After subtracting the starting spectrum from each of the succeeding spectra, factor analysis and EFA were applied to the resulting data matrix. Factor scores showed a time dependent change, but a clear difference between treated and reference beef was observed in factor 1. Eigenvalues calculated from EFA showed the existence of two vigorous digestion periods during tenderization, which supported the results from biochemical analysis.
Histological Changes in Collagen Related to Textural Development of Prawn Meat During Heat Processing
Authors: Mizuta S. , Yamada Y. , Miyagi T. , Yoshinaka R.
Published: July 2006

Heat processing enhanced firmness and degree of shrinkage deformation of kuruma prawn Penaeus japonicus meat. In histological experiments, most collagen fiber in perimysium, epimysium, and subcuticular connective tissue maintained structures after heat‐processing in hot water at 70°C for 30 min. Crude collagen fiber fractions (residues after alkali extraction, RS‐AL) prepared from the muscle were measured for hot‐water solubility and compared with the RS‐AL from the muscle of carp Cyprinus carpio. Collagen in the RS‐AL of prawn muscle had very low hot‐water solubility (about 23.5% at 70°C) compared with that of carp. These results suggested that collagen had important functions in promoting thermal shrinkage and hardening of prawn meat and in maintaining mechanical strength of heat‐processed meat.
Compressive Properties of Whey Protein Composite Gels Containing Fractionated Milkfat
Authors: Mor Y. , Shoemaker C.F. , Rosenberg M.
Published: July 2006

Compressive properties of composite gels consisting of 13% whey protein isolate (WPI) and 10% to 30% selected milkfat fractions were investigated at different temperatures. Compressive properties of gels were significantly affected by melting properties of the filler. Maximum compressive strength of composite gels was proportional to filler load and proportion of solid lipids. Compressive strength of composite gels was higher than that of WPI‐only gels, and the relative increase in hardness ranged from about 5% to 91%. Results indicated that compressive properties of gels were affected by a combined effect of filler load and temperaturedependent influence on compressive properties of matrix, interface, and filler particles.
Enzymatic Hydrolysis of Milk Proteins Under Alkaline and Acidic Conditions
Authors: Dzwolak W. , Ziajka S.
Published: July 2006

The pH‐stat and osmometric methods were adopted for control of hydrolysis of casein and whey proteins by chymotrypsin, trypsin and pepsin. Experiments in alkaline medium showed that the mean pK values determined for amino groups in milk protein hydrolysates at 52°C were 7.11 for casein hydrolysates and 7.18 for whey protein hydrolysates. During hydrolysis in acidic medium the osmotic coefficients determined for casein and whey proteins enabled calculation of the calibration factor for the osmometer (1.05) which could be assumed as constant. Results will enable monitoring of DH during hydrolysis of milk proteins in such systems.
Deamidation Kinetics of Precipitated by Carbon Dioxide Compared with Commercial Caseinates
Authors: SANTOS C. V. , TOMASULA P. M. , KURANTZ M. J.
Published: July 2006

Casein precipitated by carbon dioxide (CO2‐casein), and commercial sodium and calcium caseinates (1% w/v in water) were thermally deamidated at pH 8 for up to 96h at 85,100, and 115°C. CO2‐casein displayed the highest overall extent of deamidation at 100 and 115°C after 32 and 24h, respectively, while there was no difference at 85°C. Structural differences between CO2‐casein and the commercial caseinates may account for the difference in deamidation. Deamidation kinetics were apparent first‐order with respect to concentrations of the amides, asparagine and glutamine. Reaction rate constants and Arrhenius parameters were comparable from regression modeling.
Salmon and Trout Analysis by PCR‐RFLP for Identity Authentication
Authors: Carrera E. , Garcia T. , Céspedes A. , González I. , Fernández A. , Hernández P.E. , Martin R.
Published: July 2006

Raw and smoked Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) were differentiated by PCR amplification of a 950 bp conserved fragment of the mitochondrial 16S rRNA gene followed by restriction site analysis with the endonucleases Hpa I and Bst Ell. Salmon PCR products digested with Hpa I yielded two fragments of 804 bp and 146 bp, while trout PCR products were not cleaved by this enzyme. However, Bst Ell did not cleave salmon PCR products while two bands of 513 bp and 437 bp were produced when trout samples were cleaved with this enzyme. This genetic marker could be very useful for detecting fraudulent substitution of lower valued smoked trout.
Glycoalkaloid Content and Anthocyanin Stability to Alkaline Treatment of Red‐Fleshed Potato Extracts
Authors: Rodriguez‐Saona L. E. , Wrolstad R. E. , Pereira C.
Published: July 2006

Red‐fleshed potato (Solanum tuberosum) breeding clones were screened for steroidal glycoalkaloid (SGA) content. SGAs and anthocyanins (ACN) were characterized by HPLC and Mass Spectroscopy (MS). Total SGA ranged from 2.0 to 36.3 mg/100g tuber. Two cultivars with highest anthocyanin content, showed low levels of SGAs. The effect of alkaline treatments on SGA precipitation, anthocyanin content and profile was studied by adjusting the pH of aqueous extracts from 7.6 to 11. Complete removal of SGAs from colored extracts was achieved at pH > 9.2, however it caused substantial anthocyanin loss. Best results were obtained at pH 8.0 with 30% monomeric anthocyanin degradation and 90% SGA precipitation.
Microbiological, Chemical and Sensory Properties of Pre‐cooked Roast Beef Preserved with Horseradish Essential Oil
Authors: Delaquis P. J. , Ward S. M. , Holley R. A. , Cliff M. C. , Mazza G.
Published: July 2006

Pre‐cooked roast beef slices were stored 28 days at 4±2°C in air or 100% N2 with and without vaporized horseradish essential oil (HEO). Addition of 20 μL HEO/L restricted growth of most spoilage bacteria. Pseudomonas spp. and Enterobacte‐riaceae were strongly inhibited by HEO. Lactic acid bacteria were more resistant to the antimicrobial effect and dominated spoilage flora. Sensory evaluation and headspace analysis by gas chromatography/mass spectrometry revealed that development of off‐flavors and odors derived from fat oxidation products was delayed by HEO. Cooked meat color was also preserved in samples stored under HEO.
Barrier and Tensile Properties of Transglutaminase Cross‐linked Gelatin Films as Affected by Relative Humidity, Temperature, and Glycerol Content
Authors: Lim L.‐T. , Mine Y. , Tung M.A.
Published: July 2006

Gelatin films were prepared by enzymatic cross‐linking with transglutaminase, and their mechanical and barrier properties were evaluated as functions of relative humidity (RH, 30 to 75%), temperature (15 to 35°C) and glycerol content (15 to 31%). Water and glycerol plasticized the films synergistically, resulting in greater elongation but lower tensile strength values. Films with higher glycerol contents exhibited higher moisture contents, indicating higher hydrophilicity of the films. Permeabilities of oxygen and allyl isothiocyanate (an antimicrobial vapor from Cruciferae plants) were low when the films were dry, but increased considerably when RH>50%. Therefore, RH conditions during end‐use applications must be considered to optimize the performance of these films.
Fat Reduces Volatiles Production in Oil Emulsion System Analyzed by Purge‐and‐Trap Dynamic Headspace/Gas Chromatography
Authors: Jo C. , Ahn D.U.
Published: July 2006

Release of volatiles in oil emulsion systems containing various fat contents was determined using purge‐and‐trap dynamic headspace/gas chromatography. Oil emulsions were prepared using 0, 0.5, 1, 2, 4, or 8% oil, and a standard mixture was prepared using hydrocarbons, aldehydes, ketones, and alcohols. Fat content in oil emulsions reduced the volatility of added volatile standards, and the amount of volatiles released from oil emulsion correlated negatively with fat content (r2= 0.92 in total volatiles). Among these tested, the volatilization of ketones was least influenced by fat content. The release of nonpolar hydrocarbons was not influenced but polar compounds (aldehydes, ketones, and alcohols) were greatly influenced by water.
Gelling Temperatures of Gellan Solutions as Affected by Citrate Buffers
Authors: Mao R. , Tang J. , Swanson B.G.
Published: July 2006

Effects of citrate buffers at pH 3.5 and 5.0 on gelling temperatures of gellan solutions with 0.4–1.8% gellan and 1.5–60 mM Ca2+were studied. Partial dissociation of the carboxyl groups in gellan polymer in pH 3.5 solutions resulted in weakened gels. The pH 3.5 buffer exhibited weak chelating ability for Ca2+. The gelling temperature of gellan solutions at pH 3.5 was quantitatively related to polymer and cation concentrations using a similar model to that for gellan water solutions. The pH 5.0 buffer exhibited strong chelating ability. Gelling temperatures at pH 5.0 were generally lower than those at pH 3.5, except at low calcium concentrations.
Water Vapor Permeability of Whey Protein Emulsion Films as Affected by pH
Authors: Pérez‐Gago M.B. , Krochta J.M.
Published: July 2006

The water vapor permeability (WVP) of whey protein isolate‐beeswax emulsion films was investigated as related to pH. Lower WVP was observed for films cast from solutions at pH 7.0. When pH of the film‐forming solution was lowered, resulting film WVP increased. At the isoelectric point, WVP was the highest. As pH of the emulsion approached pI, a sharp change in viscosity occurred due to an increase in protein aggregation. This increase in viscosity probably lowered lipid mobility and reduced interconnectivity among lipid droplets, resulting in the higher WVP. For minimum WVP, such films should be applied at pH different from pI.
Formation of Heterocyclic Amines in a Meat Juice Model System
Authors: Arvidsson P. , van Boekel M.A.J.S. , Skog K. , Solyakov A. , Jägerstad M.
Published: July 2006

Bovine meat juice was used as a model system to examine the kinetics of the formation of heterocyclic amines. The formation was examined at temperatures between 100 and 225°C for 0.5‐180 min. Heated samples were subjected to solid‐phase extraction and HPLC analysis. IQx, MeIQx, 7,8‐DiMeIQx, 4,8‐DiMeIQx, PhIP, harman and norharman were identified. The formation of the IQx derivatives and PhIP followed a first‐order model Ct=B(1–ek1(t1‐t0), and the temperature dependence followed the Eyring equation k=kbT/heΔS/Re‐ΔH/RT. The parameters in the first‐order model and the Eyring equation could be estimated from our data. The degradation of heterocyclic amines at high temperatures was analyzed and the products were found to be less mutagenic.
Expression of Myosin Heavy Chain Isoforms in Porcine Muscles Determined by Multiplex PCR
Authors: Tanabe R. , Muroya S. , Chikuni K.
Published: July 2006

A cDNA sequence of 5′‐terminal region of myosin heavy chain (MHC) isoform 2x was determined. Based on this and published sequences, the procedure of reverse transcription‐polymerase chain reaction (RT‐PCR) employing a multiplex PCR technique was developed to analyze the expression patterns of MHC isoforms in porcine muscles. All four MHC isoforms in postnatal porcine muscles could be analyzed by this method and showed different expression patterns according to the porcine muscle types. The procedure developed in this study would be very useful to elucidate the relationships between meat quality and MHC isoform composition.
Characterization of Branched Oligosaccharides Produced by Bacillus licheniformis Maltogenic Amylase
Authors: Kwon K.S. , Auh J.H. , Choi S.K. , Kang G.J. , Kim J.W. , Park K.H.
Published: July 2006

Highly concentrated branched oligosaccharides (HBOS) were prepared from liquefied corn starch by a continuous process using an immobilized Bacillus licheniformis maltogenic amylase (BLMA) and yeast fermentation. Physicochemical properties of HBOS were evaluated and compared with those of sucrose and commercial oligosaccharides. An HBOS solution showed flow behavior nearly Newtonian. At relative humidities of 32% and 90%, HBOS exhibited high moisture retention and absorption properties. HBOS were relatively stable against heating at pH 3. Addition of 10–20% HBOS to starch increased its gelatinization temperature by 5–10°C. The glass transition temperature of freeze‐concentrated HBOS was higher than that of sucrose, suggesting the potential of HBOS for use in the storage of frozen foods.
Color Characteristics of Irradiated Aerobically Packaged Pork, Beef, and Turkey
Authors: Nanke K. E. , Sebranek J. G. , Olson D.G.
Published: July 2006

Color changes in irradiated meat were species‐dependent. Irradiated pork and beef became less red as a result of irradiation and display time. The redness values of turkey increased after irradiation but decreased during display time. The yellowness of the irradiated samples, for all species, increased as a result of irradiation and display. Visual evaluation of irradiated pork and beef indicated an increase in brownness, whereas turkey increased in redness as dose increased. The surface color of irradiated pork became less uniform than unirradiated pork. Reflectance spectra indicated that irradiation induced a metmyoglobin‐like pigment in pork and beef, whereas the pigment in turkey was unchanged.
Sanitizing Effects of Fruit Waxes at High pH and Temperature on Orange Surfaces Inoculated with Escherichia coli
Authors: Pao S. , Davis C. L. , Kelsey D. F. , Petracek P. D.
Published: July 2006

We determined the bactericidal activity of surface applied waxes on oranges. Effective bactericidal activity of combined alkali and heat treatments was observed on both glass slides and orange fruit surfaces. A five log reduction of Escherichia coli was attained by dipping inoculated glass slides in heated (≥50°C) alkaline (pH 10) wax solution for 4 min. A pH 11, dipping at ≥50°C for ≥2 min achieved similar bactericidal effects. On the fruit surface, wax treatments were effective at the non‐stem scar area. Thus, applied fruit waxes may be useful on raw agricultural commodities to reduce surface microbial contaminants.
Purification and Characterization of Proteinase from Atlantic Menhaden Muscle
Authors: Choi Y.J. , Cho Y.‐J. , Lanier T.C.
Published: July 2006

Two proteinases (A and B) were isolated from Atlantic menhaden muscle with molecular weights of 112,000 and 90,500 daltons, respectively. Proteinase B had higher activity than A for protein substrates except casein; proteinase B had no caseinolytic activity. Both proteinases hydrolyzed synthetic substrates such as Z‐Phe‐Arg‐NMecand TAME, but not BAEE and BAPNA. Optimum Z‐Phe‐Arg‐NMec hydrolyzing activity was shown at pH 7.4, 40 to 50 °C for both proteinases A and B. Activities of A and B in the presence of 3.0% NaCl were reduced to 71.2% and 62.2%, respectively. Both proteinases were inhibited by 1 mM TLCK, 1 mM benzamidine, 1% egg white, and 1% bovine plasma hydrolysate. Proteinases A and B are most likely tryptic serine type proteinases.
Thermal Aggregation of Whey Proteins in Model Solutions as Affected by Casein/Whey Protein Ratios
Authors: Beaulieu M. , Pouliot Y. , Pouliot M.
Published: July 2006

Model solutions (32.5 g protein/L) prepared from milk, ultrafiltration permeate, and whey protein isolate were adjusted at pH 6.7 to casein:whey protein (C:W) ratios of 80:20, 60:40, 40:60,20:80, and 0:100. Heating was performed in test tubes at 95 °C for 5 min. Observations of the heated suspensions revealed the occurrence of heterogeneous particulates from the existing casein micelles complexed with denatured whey proteins and from aggregates essentially consisting of denatured whey proteins. The proportion of whey protein aggregates increased as C:W was changed from 80:20 to 20:80. The results from this study confirmed that heat‐induced aggregates were formed not only from casein micelles but also from heat‐denatured whey proteins.
Glass Transition Temperature of Casein as Affected by Transglutaminase
Authors: Mizuno A. , Mitsuiki M. , Motoki M.
Published: July 2006

The objective of this study was to determine glass transition temperature (Tg) of a‐casein with differential scanning calorimetry (DSC) and to study the effect of microbial transglutaminase (MTG) treatment on Tg of a‐casein. MTG‐treated a‐casein was fractionated following the MTG treatment. After adjusting water content, T measurements were made by DSC and the dependencies of Tg on the water content determined. Oscillation DSC (ODSC) was also used. The determination of Tg of MTG‐treated samples by conventional DSC was unreliable. However, by comparing with ODSC data, their T could be detected. The MTG treatment elevated the Tg of a‐casein, which maybe the reason for improved stability of dry daily products during storage.
Bovine Plasma Protein Functions in Surimi Gelation Compared with Cysteine Protease Inhibitors
Authors: Kang I.S. , Lanier T.C.
Published: July 2006

The protease inhibitory activity of bovine plasma protein (BPP) and its gel strengthening effect on Pacific whiting surimi were compared with E‐64 [L‐trans‐epoxysuccinylleucylamido (4‐guanidio) butane], iodoacetic acid (IAA), and a recombinant soybean cystatin (RSC). In terms of inhibitory activity, as low as 1.2 mM E‐64,37.7 mM IAA, or 17.9 mg RSC were equivalent to 1% BPP. To produce the same gel strength as the 1% BPP‐treated surimi, 10 times that level of E‐64 and RSC were required, while 100 times that level of IAA did not increase the gel stress as effectively. Thus, plasma contributed to enhanced gelation of Pacific whiting surimi by inhibition of fish protease and also by other gel‐enhancing factors in the plasma.
Variations in Rate of Water Loss as Related to Different Types of Post‐rigor Porcine Musculature During Storage
Authors: Joo S.T. , Kauffman R.G. , van Laack R.L.J.M. , Lee S. , Kim B.C.
Published: July 2006

The changes in percent drip loss (PDL), total water content, and shrinkage at different postmortem (PM) stages were examined in four pork quality classes: pale, soft, exudative (PSE); reddish‐pink, soft, exudative (RSE); reddish‐pink, firm, non‐exudative (RFN); and dark, firm, dry (DFD). The PDL of PSE and RSE samples rapidly decreased with time, whereas those of RFN and DFD did not. Although the PDL of RSE showed a decrease (p < 0.05) with time, the percentage of total water did not change. Large pieces of loin exhibited less shrink than smaller pieces. These results indicated that water‐holding capacity, as expressed by shrinkage, improved at extended PM times.
Analyses of Glycolipids in Clove, Red Pepper, and Nutmeg by High‐Performance Liquid Chromatography
Authors: Suzuki H. , Park W‐K. , Lim S‐Y.
Published: July 2006

ABSTRACT: To determine the existence of glycolipids (neutral glycosphingolipid and glycoglycerolipid) in clove, red pepper, and nutmeg, we performed silica gel chromatography and high‐performance liquid chromatography (HPLC) using an Aquasil‐SS column and a C8‐reversed‐phase silica gel column. HPLC (Aquasil‐SS column) with a UV absorption detector was used to analyze neutral glycosphingolipid. These chromatograms showed two typical peaks in clove lipids. UV‐HPLC (C8‐reversed phase silica gel column) was also used to analyze glycoglycerolipid. The chromatograms indicated a small peak in clove lipids. Moreover, we observed the same two peaks in the glycolipid fraction of clove lipid when we used HPLC (Aquasil‐SS column) with a differential refractometer detector. These results suggest that clove may contain new and plural neutral glycosphingolipids.
Effects of Salts on the Thermal Reversibility of Starch and Hsian‐tsao (Mesona procumbens Hemsl) Leaf Gum Mixed System
Authors: Lai L.S. , Chao S.J.
Published: July 2006

ABSTRACT: Two‐cycle rapid‐visco analysis was performed on the admixture of 1% hsian‐tsao leaf gum and 2% wheat starch as a function of salt types and concentrations. The salt concentrations (Cs) studied were 5 to 75 mM for sodium and potassium chloride, and 3.4 to 8.5 mM for calcium and magnesium chloride. The gelling temperature, gelling rate and gel viscosity of the mixed system increased with increasing Cs. In addition, the melting temperature increased, but melting rate and percentage of viscosity loss decreased with increasing Cs. These results indicated the presence of appropriate amount of salts could facilitate and reinforce the formation of junction zones, and provided a more pronounced thermal resistance.
The Binding of H2O2‐Generated Fe(III) to Bifidobacterium thermophilum Depends on the Method of its Production
Authors: Kot E. , Bezkorovainy A.
Published: July 2006

ABSTRACT: Fe(OH)3 was produced from Fe(II) and H2O2 by methods associated with high and low free radical activity. More Fe(OH)3 became bound to Bifidobacterium thermophilum when the former type of method was used, and protoplasting experiments indicated that binding to both the cell walls and membranes was enhanced. Binding to cell walls was instantaneous, whilst that by the membranes increased with time using both methods. Al(III), a lipid peroxidation enhancer, increased Fe(OH)3 binding by membranes only. It was concluded that B. thermophilum is able to abate increased activity of free radicals not only by scavenging them, but also by removing iron from their environment.
The Contribution of Water to the Specific Heat Change at the Glass‐to‐Rubber Transition of the Ternary System BSA‐Water‐NaCl
Authors: Inoue C. , Ishikawa M.
Published: July 2006

ABSTRACT: We studied the glass‐to‐rubber transition of a BSA‐water‐NaCl system using DSC. The Tg was 178–187 K and decreased with increasing NaCl content from 1:9 to 6:4 NaCl:BSA. The specific heat change (ΔCp*, J/((g BSA)K)) at Tg increased as the weight ratio increased from 1:9 to 5:5 NaCl:BSA, as did the change in calculated unfrozen water (UFW). The UFW was also correlated with the amount of NaCl in the glassy region with a correlation coefficient of approx. 6 (mol H2O)/ (mol NaCl), which is comparable to the hydration number of Na+. These results suggest that UFW could contribute to the ΔC at Tg of the BSA‐water system.
Lipid Oxidation in Oil‐in‐Water Emulsions: Impact of Molecular Environment on Chemical Reactions in Heterogeneous Food Systems
Authors: MCCLEMENTS D.J. , DECKER E.A.
Published: July 2006

The susceptibility of lipids to oxidation is a major cause of quality deterioration in food emulsions. The reaction mechanism and factors that influence oxidation are appreciably different for emulsified lipids than for bulk lipids. This article reviews the current understanding of the lipid oxidation mechanism in oil‐in‐water emulsions. It also discusses the major factors that influence the rate of lipid oxidation in emulsions, such as antioxidants, chelating agents, ingredient purity, ingredient partitioning, interfacial characteristics, droplet characteristics, and ingredient interactions. This knowledge is then used to define effective strategies for controlling lipid oxidation in food emulsions.
Degradation Kinetics of Chlorophyll in Peas as a Function of pH
Authors: Ryan‐Stoneham T. , Tong C.H.
Published: July 2006

The kinetics of chlorophyll degradation in pea puree were determined in a specially designed reactor with on‐line pH control capability. Without pH control, the pH of the pea puree decreased continuously with heating due to acid formation; the pH was maintained within ±0.1 of the desired value with on‐line pH control. Chlorophyll (both a and b) degradation followed the first‐order reaction model. The temperature dependence of the rate constant was adequately modeled by the Arrhenius equation. The activation energy was independent of pH and was 17.5 kcal/mol and 17 kcal/mol for chlorophyll a and chlorophyll b, respectively. The degradation rate constant decreased log‐linearly as the pH was increased. A mathematical model was developed to predict the chlorophyll concentrations as a function of time, temperature and pH.
Residues of Ethoxyquin and Ethoxyquin Dimer in Ocean‐Farmed Salmonids Determined by High‐Pressure Liquid Chromatography
Authors: He P. , Ackman R.G.
Published: July 2006

The occurrence of residues of ethoxyquin (EQ) and ethoxyquin dimer (DM) from fish feeds in the liver and muscle of farmed salmon and steelhead was studied. For quantitative analysis of DM, the tissue was partially hydrolyzed with 50% NaOH, and then the lipid and antioxidant residues were extracted with hexane. After solvent removal and recovery into acetonitrile, DM was determined by reversed‐phase high‐pressure liquid chromatography (HPLC) with a fluorescence detector, with the excitation wavelength set at 360 nm and the emission wavelength at 440 nm. The mobile phase was acetonitrile:0.01M ammonium acetate (80:20, v:v). The EQ levels were very low, but the DM levels were higher. The recoveries from the spiked samples were 88 ± 4% for DM. Sample site determinations indicated that the DM residue level could be associated with depot fat except in the liver, where the tissue content of DM was 60% to 70% less. Similar results appear satisfactory for ethoxyquin extracted from fish oils.
Chemical, Physical, and Gel‐forming Properties of Oxidized Myofibrils and Whey‐ and Soy‐protein Isolates
Authors: Liu G. , Xiong Y.L. , Butterfield D.A.
Published: July 2006

Myofibrils, oxidized with FeCl3/H2O2/ascorbate, exhibited an increase in carbonyls and amines, SH→SS conversion, peptide scission, myosin polymerization, and a decrease in thermal stability and gel‐formation ability. Amino‐acid side chains of whey‐protein isolates (WPI) and soy‐protein isolates (SPI) were also modified during oxidation, but the thermal stability of WPI or SPI was not significantly altered. Oxidation increased elasticity of SPI gel but not that of WPI gel. Similarly, oxidation promoted interactions of myofibrils with SPI but not with WPI, resulting in > 30% increases in elasticity of the myofibril/SPI composite gel over its nonoxidized control. Hence, in processed meats where oxidation occurs, the presence of soy proteins may enhance the functionality of myofibrillar proteins.