bluuebunny/crossref_metadata_2025 huggingface dataset:
A Reliable Method of Extracting the Rheological Properties of Fruit Purees from Flow Loop Data
Authors: Yeow Y.L. , Perona P. , Leong Y.K.
Published: July 2006

A method based on Tikhonov regularization is used to process the volumetric flow rate against pressure drop data of different fruit purees generated by large‐scale flow loops. These data are converted into shear‐rate‐against‐shear‐stress curves. Curves from flow loops with different dia are compared to verify that they are independent of dia. They are also compared against that obtained by a conventional method. Tikhonov regularization will simultaneously extract the yield stress of the purees from the flow loop data. The results obtained by Tikhonov regularization show it to be a very efficient way of processing the flow loop data of rheologically complex foods.
Energy Balance of Low Hydrated Starches Transition Under Shear
Authors: Barron C. , Valle G. Della , Colonna P. , Vergnes B.
Published: July 2006

Moistened (25% to 30% total basis) starches were processed on a pre‐shearing rheometer under controlled conditions of temperature, residence time, and shear rate. The specific mechanical energy (30 to 1000 J.g‐1) was measured and starch transformations assessed. The conversion of compacted native starch into a suspension of granule fragments in a melt was modeled by a simplified energy balance of the shearing zone. A theoretical fragmentation mechanism was proposed with a critical fracture energy of 125 J.m‐2. The computed mechanical energy and time necessary for achieving this transition varied in agreement with experimental results, for different operating conditions and starch botanical origins. Interparticle friction influenced granule fragmentation, whereas crystal melting was associated with viscous dissipation.
Edible Films Prepared from Water Extract of Soybeans
Authors: Cao Y.M. , Chang K.C.
Published: July 2006

Soy films were prepared from water extract of whole soybean. The films' mechanical characteristics as affected by various solid concentrations of water‐to‐bean ratios, various plasticizer types and concentrations, and various pH values were investigated. Higher tensile strength along with lower elongation was obtained when films were prepared at 8:1 water‐to‐bean ratio. Stronger films in terms of the tensile strength and puncture strength and lower elongation were obtained when 60% of the amount of plasticizer (relative to protein content in the film) and only triethylene glycol were used. Films with lower strength and higher elongation were produced when 80% of the amount of plasticizer (relative to protein content in the film) and only glycerol were used. In the range of pH 8 to 12, pH 10 produced films with the highest tensile strength.
Ultrasonic Monitoring of Powder Dissolution
Authors: Saggin R. , Coupland J.N.
Published: July 2006

Sucrose (20 wt%) and lactose (10 wt%) powders were mixed with water (at 2, 20, and 40 °C) and allowed to dissolve. The proportion of an ultrasonic pulse reflecting at the interface between a polymer delay line and the dissolving sugars decreased during the dissolution process, and the magnitude of this signal, normalized to the echo from pure water, was proportional to only the dissolved portion. Ultrasonic reflectance is thus an appropriate sensor to monitor powder dissolution since it can distinguish dissolved and undissolved fractions without prior separation. The kinetics of sucrose dissolution were modeled using a cube‐root equation and the rate constant of the process increased with temperature.
Active Treatment of Frying Oil for Enhanced Fry‐life
Authors: Bheemreddy R.M. , Chinnan M.S. , Pannu K.S. , Reynolds A.E.
Published: July 2006

Frying experiments were conducted simulating food service operation for 10 d, with and without active treatment of frying medium. Oil samples were analyzed for free fatty acids (FFA), color, food oil sensor (FOS) readings, chemiluminescence, and total polar compounds (TPC). Daily treatment of frying oil with adsorbent was found to extend the frying life of oil by reducing the accumulation of FFA, TPC, and AOCS ‘R’ color value by 72%, 30%, and 52%, respectively.
Histamine Production by Morganella morganii in Mackerel, Albacore, Mahi‐mahi, and Salmon at Various Storage Temperatures
Authors: Kim S.H. , Price R.J. , Morrissey M.T. , Field K.G. , Wei C.I. , An H.
Published: July 2006

Morganella morganii was studied for its growth and histamine formation in mackerel, albacore, mahi‐mahi, and salmon stored at various temperatures from ‐30 °C to 37 °C. The optimal temperature for histamine formation was 25 °C. Mackerel, albacore, and mahi‐mahi were shown as good substrates for histidine decarboxylation by M. morganii at elevated temperatures (> 15 °C). M. morganii inoculated in all fish species including salmon formed histamine above the FDA guideline. Their growth was controlled by cold storage of the fish at 4 °C or below, but histamine formation was controlled only by frozen storage. Although histamine was not detected in any frozen samples, it accumulated rapidly in the previously frozen fish stored at 25 °C.
Effects of Xylanase and Peroxidase on Soluble and Insoluble Arabinoxylans in Wheat Bread Dough
Authors: Hilhorst R. , Gruppen H. , Orsel R. , Laane C. , Schols H.A. , Voragen A.G.J.
Published: July 2006

ABSTRACT: Bread doughs supplemented with xylanase and xylanase plus peroxidase were fractionated into 4 insoluble and 3 soluble fractions. Chemical analysis and high‐performance size‐exclusion chromatography analysis of apparent molecular weight distribution indicated that xylanase acts on both cold‐water‐extractable arabinoxylans and on those that can be solubilized from cell wall fragments by hot water extraction. Peroxidase action increased the amount of insoluble small cell wall fragments, notably the amount of protein and arabinoxylan. Arabinoxylans were retained in the small cell wall fragments because cross‐linking of arabinoxylans through ferulic acid residues to other arabinoxylans rendered them insoluble. Peroxidase did not affect the composition of gluten, nor was evidence obtained for peroxidase‐catalyzed cross‐linking of arabinoxylans to protein in the gluten and other fractions.
A Comparative Study on the Various In Vitro Assays of Active Oxygen Scavenging Activity in Foods
Authors: Murakami M. , Yamaguchi T. , Takamura H. , Matoba T.
Published: July 2006

ABSTRACT: Various in vitro assays of active oxygen‐scavenging activity in foods were compared by evaluating the activity of 13 food phenolic compounds and Trolox. 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH)‐HPLC and liposome oxidation methods were sensitive for these compounds, while deoxyribose oxidation and Randox kit methods were less sensitive. The deoxyguanosine oxidation method could not determine the activity since food polyphenols were pro‐oxidative in this assay. Among these assays, the DPPH‐HPLC method was shown to be the best since the liposome oxidation method is affected more by the structure of phenolic compounds than the DPPH‐HPLC method.
Dynamic Viscoelastic Properties of Heated Gluten/Soy Protein Gels
Authors: Apichartsrangkoon A.
Published: July 2006

ABSTRACT: Hydrated gluten, soy concentrate, and mixtures of both were heated at 90 °C for 0.5 to 6 h. All heated samples were analyzed for viscoelastic properties and SDS‐PAGE electrophoretograms. Results of the rheological analysis showed storage (G′) andloss (G″) moduli of gluten increased sharply as a result of heating and the shapes of both shear moduli were significantly different from the unheated samples. In the soy system, both shear moduli increased slightly upon heating and the shapes were similar to the unheated samples. The linkages found in the heated systems were disulfide bonds as shown by the electrophoretograms.
Influence of Modified Starches on the Stability of Beef Jerky Analogs During Storage
Authors: Ioffe M.L. , Moraru C.I. , Kokini J.L.
Published: July 2006

ABSTRACT: Textural stabilization of extruded beef jerky analogs (BJA) by using modified starches was studied. From a series of modified starches studied, Frigex W and Instant Pure Flo were identified to show very reduced retrogra‐dation, both in gels and after extrusion. These starches were used as textural stabilizers for BJA, an extruded product obtained from potato granules and ground beef. The partial substitution of potato granules with modified starches, at a level of 5% of the formulation, led to increased moisture sorption capacity of the analogs. After a storage period of 1 mo, the samples that contained modified starch had a degree of swelling with 30% higher and much lower elastic modulus as compared to those that contained only potato starch.
Heat Curing of Soy Protein Films at Atmospheric and Sub‐atmospheric Conditions
Authors: Kim Ki Myong , Weller C.L. , Hanna M.A. , Gennadios A.
Published: July 2006

ABSTRACT: The effect of heat curing at atmospheric or subatmospheric conditions on selected properties (moisture content, water vapor permeability (WVP), color, tensile strength (TS), elongation (E), and total soluble matter (TSM) content) of cast soy protein isolate films was investigated. Films were heat cured at 85 °C for 6, 12, 18, or 24 h at absolute pressures of 101.3, 81.32, or 61.32 kPa. Heat‐cured films had increased (P < 0.05) TS and decreased (P < 0.05) WVP and E compared to control, unheated films. Heat treatment under vacuum reduced the WVP of films faster than heat curing at atmospheric pressure. High TS values, low E values, and low TSM values were also reached within short heating time under vacuum. However, vacuum treatment increased the size and number of cavities in cured films as evidenced by scanning electron micrographs.
Statistical Modeling of D‐ and z‐value of E. coli O157:H7 and pH in Apple Cider Containing Preservatives
Authors: Steenstrup L.L. , Floros J.D.
Published: July 2006

ABSTRACT: The objective of this study was to model the heat resistance of E. coli O157:H7 in apple cider as a function of added sorbate, benzoate, and malic acid. Inactivation experiments were done at 47, 50, and 53 °C, and D and z values were calculated. Models for D47, D50, and D53 showed that all 3 additives significantly decreased heat resistance. Furthermore, z‐values increased with addition of preservatives and low pH. Model predictions showed that at 50 °C, 5‐log reduction is attainable in a few minutes when the cider contains additives, while preliminary test results showed that at 20 °C, a 5‐log reduction could be obtained in about 90 min in cider with 0.1% sorbate, 0.1% benzoate, and 1% malic acid.
Casein Hydrolysate Fractions Act as Emulsifiers in Process Cheese
Authors: Kwak H.S. , Choi S.S. , Ahn J. , Lee S.W.
Published: July 2006

ABSTRACT: Degrees of hydrolysis and emulsifying activity of casein hydrolysates were the highest at 4 h hydrolysis. The oil‐off values of the mixture of hydrolysate (H) or supernatant (S) and traditional emulsifier (T) were not significantly different from the control made with traditional emulsifier, except for S + T = 3:1. Two other samples made with hydrolysate or supernatant only (H or S) showed higher oil‐off value than the others (p < 0.05). In flavor property, no difference was found between samples made with traditional emulsifier and those made with the mixture of hydrolysate or supernatant at the ratio of 3 to 1. Therefore, these results indicated that a mixture of the hydrolysate or supernatant and traditional emulsifier might replace a traditional emulsifier in process cheese manufacturing.
A Comparison of 14 Jams Characterized by Conventional Profile and a Quick Original Method, the Flash Profile
Authors: Dairou V. , Sieffermann J.‐M.
Published: July 2006

ABSTRACT:Flash Profile (FP) is a sensory descriptive method derived from Free Choice Profiling where each subject chooses and uses his/her own words to evaluate the whole product set comparatively. Two different panels were set up in order to compare the efficiency of FP with conventional profile on the same 14 products (red fruit jams). The 2 procedures produced similar information both in respect to the way the jams grouped and differed from another. However, FP proved to be faster than conventional profile but less self‐explanatory from a semantic point of view. Flash profile appears to be an interesting alternative method to evaluate quickly an array of products.
Investigating Influence of pH and Parts on Sensory Characteristics and Volatile Components in Boiled Squid Using Experimental Designs
Authors: Morita K. , Kubota K. , Aishima T.
Published: July 2006

ABSTRACT: The aroma property of boiled squid was quantitatively described using 10 sensory attributes. From screening experiments based on a Plackett‐Burman design, pH and parts of squid were selected as significant factors for generating the “cooked squid” aroma. Squid samples prepared according to a 3‐level full‐factorial design for pH and parts showed that “sweet,”“roasted shrimp,”“cooked fish,” and “cooked squid” scores were higher in both muscle and muscle with skin at pH 6.5. Response surface models calculated for each of the attributes showed how pH and parts influenced their strength. Partial least squares regression analysis applied to the sensory and GC‐MS data revealed that every attribute could be predictable (R2≥ 0.956) using a small number of informative peaks.
The Effect of Post‐Cooking Holding Times on Sensory Assessment of Low‐ and High‐Fat Beefburgers
Authors: Dreeling N. , Allen P. , Butler F.
Published: July 2006

ABSTRACT: The effect of post‐cooking holding‐time on sensory assessment of low (89 g/kg) and high (218 g/kg) fat beefburgers was assessed. Burgers were served to panelists approximately 3 or 18 min after cooking. Fat content influenced fattiness, moistness/juiciness and overall appearance (P < 0.05), overall acceptability and overall texture (P< 0.01) and tenderness and crumbliness (p<0.001). Burgers with the higher fat content had higher scores. Holding‐time influenced sensory overall appearance only with lower scores at extended holding times (P < 0.01). Treatment differences were small, mostly less than one sensory scale unit. Higher lightness and yellowness values were found for burgers with higher fat contents.
Relationship between Sensory and Instrumental Hardness of Commercial Cheeses
Authors: Xiong R. , Meullenet J‐F. , Hankins J.A. , Chung W.K.
Published: July 2006

ABSTRACT: The effect of deformation (10% to 90%) and deformation rate (0.2 to 10 mm/s) on both maximum compression force and correlation between sensory and instrumental measurements of hardness were investigated for 26 commercial cheeses. Log‐linear regression models were used to model the relationship between deformation rate and maximum compression force and fitted well to the relationship, indicating that maximum compression force is a log linear function of deformation rate. Deformation had a large effect on the correlation between sensory and instrumental hardness, while deformation rate had a small effect. The optimal deformation and deformation rate for the maximum correlation were 70% to 90% and 1.0 mm/s, respectively. This implies that an optimal combination of deformation and deformation rate can be used for maximizing the correlation between sensory and instrumental hardness for cheese products.
Effect of Turkey Meat, Phosphate, Sodium Lactate, Carrageenan, and Konjac on Residual Nitrite in Cured Meats
Authors: Kilic B. , Cassens R.G. , Borchert L.L.
Published: July 2006

ABSTRACT: Wieners were chosen as the model system. They were made with mechanically separated turkey meat (MST) and retained more residual nitrite than other such sausages (p < 0.01). Use of sodium tripolyphosphate resulted in a slightly higher residual nitrite in the finished product (p < 0.05). Wieners containing both MST and sodium tripolyphosphate, or either MST or sodium tripolyphosphate showed higher pH values than the control group. A relationship between product pH and residual nitrite level was observed. Wieners retained more residual nitrite at higher pH. Addition of sodium lactate, carrageenan, and konjac to the wiener formulation did not influence the residual nitrite level in the finished product.
Variation in Minnesota HRS Wheats: Bran Content
Authors: Peterson D. , Fulcher R.
Published: July 2006

ABSTRACT: Bran content in both wheat‐meal and flour was measured using an automated fluorescence microscopic imaging instrument, and correlated with milling extraction, ash content, and test weight values. Quantitative image analysis of the kernel bran content revealed differences in the linear response and slope, when plotted against test weight for common Minnesota HRS wheat varieties or a correlation coefficient of‐0.818 for all HRS wheat samples (sample number = 65, p = 0.01). Whole‐wheat bran and ash values also correlated significantly (p = 0.01) with the percent milling extraction (‐0.927 and ‐0.687, respectively). The flour bran content was not significantly correlated with flour ash content (0.202).
Water Sorption and Crispness of Fat‐Free Apple Chips
Authors: Konopacka D. , Plocharski W. , Beveridge T.
Published: July 2006

ABSTRACT: Equilibration of fat‐free apple chips to predetermined moisture level was achieved by keeping samples over saturated salt solutions. The sorption isotherm obtained indicated absence of a monolayer and was typical for type III according to the Brunauer classification. At water activity below 0.12 apple chips demonstrated excellent crispness and were highly acceptable as a snack food item. They were extremely hygroscopic and lost crispness easily. The critical water activity was found to be ac= 0.18 which corresponds to a water content of 3.5 g H2O/100 g solids. These values were much lower than those found for other crispy snack foods.
Phenolic Composition of Authentic Pineapple Juice
Authors: Wen L. , Wrolstad R.E.
Published: July 2006

ABSTRACT: The phenolic composition of authentic pineapple juice concentrate was analyzed by HPLC. Nine major peaks accounting for 70% of total peak area were characterized and their concentrations measured in 54 commercial samples. Means and standard deviations were as follows (mg/100 mL single‐strength juice, normalized to 12.8 °Brix): tyrosine, 3.6(1.4); serotonin, 1.8(0.8); dimethylhydroxylfuranone, 1.4(0.7); dimethylhydroxylfuranone β‐glucoside, 6.2(3.0); tryptophan, 2.2(0.9); S‐sinapyl‐L‐cysteine, 1.1(0.6); N‐γ‐L‐glutamyl‐S‐sinapyl‐L‐cysteine, 2.3(1.1); S‐sinapyl glutathione, 5.4(1.4); and a p‐coumaric acid‐like phenolic compound (calculated as p‐coumaric acid), 0.5(0.4). This information will be useful for evaluation of authenticity and quality.
Tensile and Barrier Properties of Edible Films Made from Whey Proteins
Authors: Fang Y. , Tung M.A. , Britt I.J. , Yada S. , Dalgleish D.G.
Published: July 2006

ABSTRACT: Whey protein isolate (WPI)‐based edible biopolymer films were prepared using a film‐forming stage designed to provide heat‐induced gelation. Effects of whey‐protein ratios, calcium, glycerol (plasticizer), and emulsion droplet incorporation on film tensile and barrier properties were investigated. Protein ratios had less influence on tensile strength, elongation, and water vapor permeability than glycerol and calcium ion concentrations. Semitransparent films with reasonably high tensile and UV‐light barrier properties and moderate water vapor barrier properties were prepared from WPI:20% glycerol:10 mM calcium solutions. Microstructure analysis revealed the influence of glycerol and calcium concentrations on gel networks, which could be related to film tensile properties.
Effects of Arabinoxylans on Thermal Behavior of Frozen Wheat Doughs as Measured by DSC, DMA, and DEA
Authors: Laaksonen T. J. , Kuuva T. , Jouppila K. , Roos Y.H.
Published: July 2006

ABSTRACT: The effects of water extractable arabinoxylans (WEA) on physical state of frozen wheat dough with added sucrose, NaCl, and their mixture were investigated using DSC, DMA, and DEA. DSC thermograms were obtained for annealed samples, and they showed only an endothermic peak of ice melting. Annealed samples were also analyzed using DMA and DEA with both dynamic heating and isothermal steps. Added sucrose and NaCl decreased the onset temperature of ice melting and it decreased with increasing WEA concentration. Isothermal measurements showed an a‐relaxation peaks, taken as the Tg′. Added NaCl had a great depressing effect on the Tg′ at low frequencies as measured by DEA.
Optimization of the Supercritical Fluid Extraction of Natural Vitamin E from Wheat Germ Using Response Surface Methodology
Authors: Ge Y. , Ni Y. , Yan H. , Chen Y. , Cai T.
Published: July 2006

ABSTRACT: Natural vitamin E was extracted by supercritical fluid extraction of carbon dioxide (SFE‐CO2) from wheat germ. Several SFE‐CO2 parameters, such as extracting pressure, extracting temperature, and flow rate of carbon dioxide were examined as the independent variables of central composite rotate design (CCRD). Through the response surface methodology (RSM), the optimal processing conditions were determined and the quadratic response surfaces were drawn from the mathematical models. The results demonstrated that the extracting pressure, temperature, pressure × temperature interaction, and flow rate of CO2 significantly affected the yield of the natural Vitamin E's extraction, while two interactions containing the flow rate of CO2 had no significant effect on the yield of natural vitamin E. The optimal processing conditions of the extraction of natural vitamin E in wheat germ by SFE‐CO2 were: extracting pressure 5000 PSI, extracting temperature 316 K, and flow rate of carbon dioxide 1.7 ml/min. Optimum value predicted by RSM for the concentration of natural vitamin E was 2307 mg/100g. Close agreement between experimental and predicted values was obtained.
Development of an Enzymic Time Temperature Integrator for Sterilization Processes Based on Bacillus licheniformis α‐amylase at Reduced Water Content
Authors: Guiavarc'h Y.P. , Deli V. , Van Loey A.M. , Hendrickx M.E.
Published: July 2006

ABSTRACT: The thermal stability of Bacillus licheniformis α‐amylase at low moisture content was studied, based on isothermal experiments performed in a temperature range 113 to 125 °C. The thermal inactivation was monitored by measuring the decrease in thermal denaturation enthalpy and/or the decrease in enzymic activity on pnitrophenyl‐α‐D‐maltoheptaoside, or on starch as a substrate. Based on enthalpy readings, an enzymic system with a z‐value of 10.4 °C was observed when using a relative humidity of 81% at 4 °C. A theoretical study showed that this system could be used as a Time Temperature Integrator (TTI) to monitor the safety of sterilization processes of numerous food products.
Community Leader Response to Educational Information about Biotechnology
Authors: Bruhn C. , Mason A.
Published: July 2006

ABSTRACT: Although response to biotechnology by United States consumer is positive, many know little about it, and some question risks and benefits. This project evaluated how science‐based information affects community leaders' attitudes. A videotape providing a consistent message was developed and shown in 1995 to 365 California and Indiana consumers who then participated in a discussion and completed questionnaires. Providing a realistic perspective of the risks and benefits associated with biotechnology reinforced consumers' positive attitudes and enhanced their regard for the participating university. After the program, those believing that biotechnology offers society many benefits increased from 33% to 63%. A minority of consumers viewed biotechnology negatively, uncertain about cross‐species transfer and unexpected changes.
Optimization of Gluten‐Free Bread Prepared from Cornstarch, Rice Flour, and Cassava Starch
Authors: Sanchez H.D. , Osella C.A. , de la Torre M.A.
Published: July 2006

ABSTRACT: The proportions of cornstarch, cassava starch, and rice flour were optimized for production of gluten‐free bread (with 0% and 0.5% soy flour) to maximize specific volume (Y1,Y1′), crumb‐grain score (Y2,Y2′), and bread score (Y3,Y3′). A central composite design involving cornstarch/cassava starch ratio (X1) and rice flour/cassava starch ratio (X2) was used, and 2nd‐order models for Y1 and Y1′ were employed to generate response surfaces. The maxima of response surfaces for crumb‐grain score and bread score indicate that optimal gluten‐free bread can be prepared from 74.2% cornstarch, 17.2% rice flour, and 8.6% cassava starch. Addition of soy flour at the 0.5% level also improved bread texture.
Oxidation of Polyphenols and the Effect on In vitro Iron Accessibility in a Model Food System
Authors: Matuschek E. , Svanberg U.
Published: July 2006

ABSTRACT: Tannic acid and green tea extract were added to a model food system of wheat bread, before and after incubation with polyphenol oxidase (mushroom tyrosinase), and the effect on In vitro iron accessibility was studied. Tannic acid and green tea extract had a marked inhibitory effect on the In vitro accessibility of iron when added to the model food system. Incubation of the polyphenols with tyrosinase before addition to the model food system significantly increased the accessibility of iron. The results from the study therefore suggest that oxidation of polyphenols may be a promising way to increase the bioavailability of iron in polyphenol containing foods.
Ligand and Flavor Binding Functional Properties of β‐Lactoglobulin in the Molten Globule State Induced by High Pressure
Authors: Yang J. , Powers J.R. , Clark S. , Dunker A.K. , Swanson B.G.
Published: July 2006

ABSTRACT: β‐lactoglobulin (β‐LG) in the molten globule state induced by high hydrostatic pressure (HHP) at 500 MPa and 50 °C for 32 min exhibited a significant decrease in affinity for retinol and a significant increase in affinity for cis‐parinaric acid (CPA) and 1‐anilino‐naphthalene‐8‐sulfonate (ANS) compared to native β‐LG. The number of β‐LG binding sites for retinol and CPA significantly decreased after HHP treatment. The HHP‐induced molten globule state of β‐LG exhibited less affinity for palmitic acid, capsaicin, or carvacrol ligands than native β‐LG, and no detectable specific binding for α‐ionone, β‐ionone, cinnamaldehyde or vanillin flavors. HHP treatment resulted in changes in the hydrophobic calyx and surface hydrophobic sites of β‐LG.
Singlet Oxygen Detection in Skim Milk by Electron Spin Resonance Spectroscopy
Authors: Bradley D.G. , Lee H.O. , Min D.B.
Published: July 2006

ABSTRACT: 2,2,6,6‐Tetramethyl‐4‐piperidone (TMPD) can react with singlet oxygen to produce the corresponding nitroxide, 2,2,6,6‐tetramethyl‐4‐piperidone‐1‐oxyl (TAN), which can be detected by electron spin resonance (ESR) spectroscopy. ESR detected the formation of TAN in 5 μM riboflavin phosphate buffer, or skim milk containing 20 mM TMPD during illumination. The effects of illumination, riboflavin, and oxygen on the formation of TAN indicated that the presence of each was required for singlet oxygen formation. The photo reduced riboflavin might reduce TAN to the hydroxylamine of TAN, thus decreasing the paramagnetic TAN signal. Maximum concentration of TAN was obtained at an added 10 mM riboflavin in buffer solution or in skim milk after 15 min of illumination in the presence of oxygen.
Dependence of Coating Thickness on Viscosity of Coating Solution Applied to Fruits and Vegetables by Dipping Method
Authors: Cisneros‐Zevallos L. , Krochta J.M.
Published: July 2006

ABSTRACT: Hydroxypropyl methylcellulose solutions were used as coating systems in this study and solution concentrations, viscosity, densities, and surface tensions were characterized. Fuji apples were coated by dipping and stored 4 d at room temperature, after which the internal oxygen and carbon dioxide were measured. Results indicated that coating thickness varied with viscosity, concentration, density, and draining time of the biopolymer solution. Coating thickness relates to the square root of viscosity and the inverse square root of draining time, which agrees with the theoretical approach for flat plate dip‐coating inlow‐capillary‐number Newtonian liquids. These results indicate the possibility of controlling coating thickness and internal gas composition based on coating solution properties. Keywords: coating thickness, viscosity, fruits, vegetables, modified atmosphere
Processing of Sapota (Sapodilla): Drying
Authors: Ganjyal G.M. , Hanna M.A. , Devadattam D.S.K.
Published: July 2006

ABSTRACT: The drying characteristics of sapota (Achras zapota, cv, Kalipatti), a tropical fruit crop, were studied. Fruits were cut in sizes of half, quarter, and 5 mm slices and dried at temperatures of 55, 60, 65, and 70 °C in convection air and vacuum ovens. Moisture content of the fruit reduced from 72 to 78% (w.b) to 8.5 to 12.5% (w.b.) with drying times of 15 to 35 h in a convection air oven and of 14 to 31 h in a vacuum oven. Log and modified log models were fitted for the drying data. Empirical models were developed to predict drying constants as a function of drying temperature and sizes of samples with good correlation. Keywords: sapota, sapodilla, drying
Changes in Temperature and Structure of Agar Gel as Affected by Sucrose During High‐pressure Freezing
Authors: Fuchigami M. , Teramoto A.
Published: July 2006

ABSTRACT: To determine the effects of high‐pressure freezing, agar gel with 0, 5, 10, or 20% sucrose were frozen at 0.1 to about 686 MPa and ‐20 °C. Exothermic peaks were detected at 0.1, 100, 500 to about 686 MPa (freezing). However, at approximately 200 to 400 MPa, gel did not freeze but froze during pressure release. Thus, structure of gel frozen at approximately 200 to 400 MPa was better than other samples due to quick freezing. The phase transition from high‐pressure‐ices to ice I at ‐20 °C might have promoted the growth of ice crystals. With the addition of sucrose, the initial freezing temperature decreased and structural quality improved. Keywords: high pressure, agar gel, freezing, texture, ice crystals
Moisture Diffusivity in Sponge Cake as Related to Porous Structure Evaluation and Moisture Content
Authors: Guillard V. , Broyart B. , Bonazzi C. , Guilbert S. , Gontard N.
Published: July 2006

ABSTRACT: Water diffusivity within sponge cake was determined at 5, 20, and 25 °C by identification from a water sorption kinetic and using a mathematical model based on Fick's 2nd law. Water diffusivity at 20 °C within sponge cake varied from 0.5 × 10‐10 m2/s to 7.5 × 10‐10 m2/s as a function of sponge cake moisture content. Influence of temperature on the concentration‐dependent diffusivity was investigated. The activation energy was found to vary with sponge cake moisture content from 84 to 128 kj/mole. Effective diffusivity variations were correlated with the changes in microstructure of the material that was observed by using environmental scanning electron microscopy. The level of porosity in the material played a dominant role in determining the effective diffusivity.
Apple Rings as a Model for Fruit Drying Behavior: Effects of Surfactant and Reduced Osmolality Reveal Biological Mechanisms
Authors: Bengtsson G.B. , Rahman M.S. , Stanley R.A. , Perera C.O.
Published: July 2006

ABSTRACT: Drying behavior at 60 °C was studied in uniform rings of apple fruit parenchyma after vacuum infiltration of fluids with different osmolality and surface tension. All infiltrations gave a halved final porosity. Both reduced surface tension and reduced osmolality caused tissue destruction shown as darker visual color. Addition of surfactant resulted in a higher drying rate on a surface area basis corresponding to 15% more water lost after 2 h. The results indicate that biological mechanisms related to function and structure of living tissue are important for drying behavior. The apple ring model is suitable for further studies of biological and other types of drying behavior in relation to the tissue organization.
Gelation Properties and Morphology of Heat‐induced Starch/Salt‐soluble Protein Composites
Authors: Li J.‐Y. , Yeh A.‐I
Published: July 2006

ABSTRACT: The formation of starch (potato, corn, and rice) and ham salt‐soluble protein (SSP) composite during heating was studied using thermal and rheological analysis. Measurements from differential scanning calorimetry showed that the peak temperature of starch/SSP composite was slightly lower than that of the corresponding starch. SSP exhibited an initial G' higher than zero and became a rigid structure as indicated by the decrease in tan δ after heating. The data of tan 8 δ illustrated that starch and protein transition proceeded independently. Scanning electron microscopy and light microscopy with the aid of histologic technique revealed the network and distribution of starch and protein in starch/SSP composite.
Effect of Edible Coating Process and Irradiation Treatment of Strawberry fragaria spp. on Storage‐keeping Quality
Authors: Vachon C. , D'Aprano G. , Lacroix M. , Letendre M.
Published: July 2006

ABSTRACT: Gamma‐irradiation and various edible coatings were tested on fresh strawberries (Fragaria spp.) for keeping fruit quality and extending shelf life. Four coatings based on milk protein were evaluated. In 1 experiment, coating formulation based on caseinate and/or strawberries were irradiated using a 60Co source. Both gamma‐irradiation treatment and edible coating process significantly delayed (p ≤ 0.05) molds growth. Edible coating based on irradiated caseinate was more effective than that of unirradiated caseinate. In a 2nd experiment, 3 irradiated coatings based on calcium caseinate and whey proteins were evaluated. The coating formulation based on 1:1 caseinate‐whey was found to be more effective than those based on calcium caseinate. Addition of calcium chloride or a mixture of pectin and agar increased the effectiveness of the coating by delaying molds' apparition.
An Artificial Neural Network Approach to Escherichia Coli O157:H7 Growth Estimation
Authors: Garcíaa‐Gimeno R.M. , Hervás‐Martíanez C. , Barco‐Alcalá E. , Zurera‐Cosano G. , Sanz‐Tapia E.
Published: July 2006

ABSTRACT: Artificial neural networks (ANN) was evaluated and compared with Response Surface Model (RSM) results using growth response data for E.coli O157:H7 as affected by 5 variables: pH, sodium chloride, and nitrite concentrations, temperature, and aerobic/anaerobic conditions. The best ANN obtained, where the 2 kinetic parameters, growth rate and lag‐time, were estimated jointly, contained 17 parameters and displayed a slightly lower Standard Error of Prediction (% SEP) than those obtained with RSM. Mathematical lag‐time validation with additional data gave a lower %SEP for ANN (18%) than for RSM (27%), although growth‐rate values were the same (22%). ANN thus should provide the innovative possibility of obtaining a single predictive model for the estimation of several kinetic parameters.
Relationship Between Astringency and Chitosan‐Saliva Solutions Turbidity at Different pH
Authors: Rodríguez M.S. , Albertengo L.A. , Vitale I. , Agulló E.
Published: July 2006

ABSTRACT: The astringency stimulus perceived when chitosan is dissolved in acidic medium and the development of turbidity when the biopolymer interacts with saliva were investigated by sensory and chemical tests. Sensory tests showed a high correlation among the judges as astringency intensity increased when solution pH decreased. Chemical tests measured turbidity development, which decreased as pH increased until pH 4.6. When pH values were between 4.6 and 6.3, chitosan solutions interaction with saliva showed the same behavior, although with a less sharp slope of regression. Both methods demonstrated that the relationship between oral astringency and turbidity could be related to salivary protein precipitation.
Warner‐Bratzler Shear Force Repeatability in Beef Longissimus Steaks Cooked With a Convection Oven, Broiler, or Clam‐shell Grill
Authors: Kerth C.R. , Blair‐Kerth L.K. , Jones W.R.
Published: July 2006

ABSTRACT: Repeatability of Warner‐Bratzler shear (WBS) force in beef loin strip steaks was determined using a small kitchen clam‐shell grill (GRILL), oven roasting (OVEN), or oven broiling (BROIL). Cooking time for the GRILL method (7.0 min) was shorter, and the OVEN method (22.8 min) was longer compared with the BROIL cooking method (17.5 min, P< 0.001). WBS values across all cooking methods ranged from 1.5 to 7.5 kg. Repeatability of WBS was relatively high for BROIL (r = 0.83), GRILL (r = 0.88), and OVEN (r = 0.88) cooking methods. Grilling beef loin steaks with an inexpensive clam‐shell grill is an acceptable method for cooking steaks for research purposes.
Lipid Oxidation in Poultry Döner Kebab: Pro‐oxidative and Anti‐oxidative Factors
Authors: Kilic B. , Richards M.P.
Published: July 2006

ABSTRACT: The effect of mechanically separated turkey (MST), ascorbate, and vacuum packaging on rates of lipid oxidation in chicken döner kebab during storage at 4 °C or ‐20 °C was investigated. MST and MST/ascor‐bate accelerated lipid oxidation compared to control kebab. Ascorbate application and vacuum packaging inhibited lipid oxidation. The antioxidative effect of ascorbate in the absence of MST was converted to a pro‐oxidative effect in the presence of MST. This suggests that the excess lipid hydroperoxides and iron complexes in MST were activated as lipid oxidation catalysts by ascorbate to overwhelm the ability of ascorbate to inhibit lipid oxidation at lower concentrations of hemoglobin, iron, and peroxides.
In Vitro Iron Bioavailability and Antioxidant Activity of Raisins
Authors: Yeung C.K. , Glahn R.P. , Wu X. , Liu R.H. , Miller D.D.
Published: July 2006

ABSTRACT: Iron bioavailabilities and antioxidant activities of 3 generic raisin types‐Golden Thompson, Dipped Thompson, and Sun‐dried Thompson‐were quantified and compared. Iron bioavailability was assessed with an in vitro digestion/Caco‐2 cell culture model using cell ferritin formation as an index of iron bioavailability. Antioxidant activity was determined using the total oxyradical‐scavenging capacity (TOSC) assay. Ferritin formation in Caco‐2 cells was low for all 3 raisin types, indicating low iron bioavailability. Ethylenediaminetetraacetic acid (EDTA) enhanced iron bioavailability from raisins but ascorbic, citric, and tartaric acids showed no effect. Antioxidant activity was significantly higher in Golden Thompson than Dipped Thompson and Sun‐dried Thompson, suggesting that enzymatic browning negatively affected antioxidant activity.
Characterization and Functionality of Frozen Muscle Protein in Volador (Illexcoindetii), Pota (Todaropsis eblanae), and Octopus (Eledone cirrhosa)
Authors: Ruiz‐Capillas C. , Moral A. , Morales J. , Montero P.
Published: July 2006

ABSTRACT: Three species of cephalopods: volador (Illex coindetii), pota (Todaropsis eblanae), and octopus (Eledone cirrhosa) were classified according to sex, stage of sexual development, and anatomical zone for characterization and functionality of their muscle proteins. The 3 species exhibited very similar levels of total protein. Octopus mantles and arms contained the least proline and the most hydroxyproline. The highest solubility values in immature pota coincided with the lowest apparent viscosity and emulsifying capacity values. The highest insolubility values observed in octopus coincided with the highest viscosity and emulsifying capacity values. However, in volador which exhibited an intermediate solubility, viscosity was very high and emulsifying capacity was very low.
Measurements of δD and δ18O Stable Isotope Ratios in Milk
Authors: Lin G.P. , Rau Y.H. , Chen Y.F. , Chou C.C. , Fu W.G.
Published: July 2006

ABSTRACT: This study explores the possibility of distinguishing raw and reconstituted milk by stable isotope ratio mass spectrometry. Considering variations from different areas and seasons, milk and groundwater samples were collected from dairy farms in different seasons to measure δD and δ18O values. Results showed differences between raw and reconstituted milk prepared with groundwater from a laboratory and a farm. The plot of values in each mixed level of raw and reconstituted milk had a correlation coefficient > 0.9. Data showed raw milk is related to the groundwater from that farm. We concluded that the charcoal treatment method is a suitable method for large‐scale monitoring of raw milk samples. The measurement of δD and δ18O values in raw milk and groundwater provides a reference to detect adulteration.
Effect of Disulfide Bond Reduction on Bovine Serum Albumin‐Stabilized Emulsion Gel Formed by Microbial Transglutaminase
Authors: Kang Y.N. , Kim H. , Shin W.‐S. , Woo G. , Moon T.W.
Published: July 2006

ABSTRACT: Polymerization by microbial transglutaminase (mTGase) of disulfide bond‐cleaved bovine serum albumin treated with 2‐mercaptoethanol was investigated in an oil‐in‐water model emulsion system. Fluorescence and circular dichroism spectroscopy revealed that conformational changes in tertiary structure were more distinct as compared with the secondary structure. Reduced protein was polymerized more effectively by mTGase. Highest storage modulus was observed in the emulsion gel formed by both 2‐ME and mTGase treatments. The phase angle was less than 45° in all samples with 2‐ME and enzyme treatments, an indication that the conformational changes due to the reduction and polymerization contribute significantly to the formation of emulsion gels.
Irradiation Effects on Free Radical Scavenging and Antioxidant Activity of Phytic Acid
Authors: Ahn H.J. , Kim J.H. , Yook H.S. , Byun M.W.
Published: July 2006

ABSTRACT: Free radical scavenging and antioxidant activities of irradiated phytic acid at various concentrations were studied. Phytic acid sodium salt dissolved in deionized distilled water was irradiated at 0, 5, 10, 15, and 20 kGy. The degradation of phytic acid by irradiation was observed, and it was found that the concentrations had an effect on the degree of degradation. Stable 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging ability of phytic acid was significantly increased by irradiation (P < 0.05) and was positively correlated with irradiation dose (P < 0.01). Antioxidant activity of phytic acid in lipid model systems was slightly increased by irradiation; however, at higher concentrations, the activity was reduced or was the same compared with nonirradiated phytic acid.
Oxidative Stability, Structure, and Physical Characteristics of Microcapsules Formed by Spray Drying of Fish Oil with Protein and Dextrin Wall Materials
Authors: Kagami Y. , Sugimura S. , Fujishima N. , Matsuda K. , Kometani T. , Matsumura Y.
Published: July 2006

ABSTRACT: Maltodextrins and a highly branched cyclic dextrin (HBCD) were tested for their ability to serve as wall materials for microcapsules with proteins. HBCD or a maltodextrin of DE18 with sodium caseinate (SC) improved the oxidative stability of encapsulated fish oil; however, the DE18/SC wall system had 2 disadvantages: browning induced by the Maillard reaction and agglomeration. The oil load level and the selection of dextrin strongly affected the outer topography and the inner structure, as well as the ratio of the oil to dextrin on the surface of the microcapsules. It is stated that drying speeds of dextrin and oil load levels were shown to be likely related to the structural difference in the microcapsules.
Effect of Calcium on Physicochemical Properties of Fat‐free Mozzarella Cheese
Authors: Joshi N.S. , Muthukumarappan K. , Dave R.I.
Published: July 2006

ABSTRACT: Fat‐free mozzarella cheeses containing 4 levels of calcium (0.79%, 0.66%, 0.59%, and 0.50%) were manufactured on 4 separate occasions. Meltability as softening time and temperature, melting time and temperature, flow rate, extent of flow, decrease in cheese height during melting, melt area, whiteness (L* value) at 5 and 60 °C and proteolysis were evaluated on 1, 7, 15, and 30 d. Reduction of 35% of the calcium increased the cheese flow to 2.5 times and the cheese also required 19% less time to melt. Low‐calcium fat‐free cheeses required lower temperature and less time to soften and melt, and had greater and faster flow. Whiteness decreased and proteolysis was greater in low‐calcium cheeses.
Physicochemical Properties of a Time‐Temperature Indicator Based on Immobilization of Aspergillus oryzaeα‐Amylase in Polyacrylamide Gel as Affected by Degree of Cross‐linking Agent and Salt Content
Authors: Raviyan P. , Tang J. , Orellana L. , Rasco B.
Published: July 2006

ABSTRACT: Currently available time‐temperature indicators (TTIs) with favorable thermal inactivation kinetics are physically incompatible with microwave or radio frequency systems. Here, TTIs for microwave and radio frequency food pasteurization processes were developed that have dielectric properties that match target foods. The TTI can be easily recovered from a food and assayed using a rapid, simple colorimetric assay. Enzyme recovery was reduced by 8% but diffusion was retarded by 20% when bisacrylamide content was increased from 3.3% to 5.3%. The specific enzyme activity was highest in 20% polyacrylamide gels containing 2% NaCl. The residual enzyme activity in the TTI following 2 mo of storage at 8 °C exceeded 70%.
Use of Conventional Media and Thin Agar Layer Method for Recovery of Foodborne Pathogens from Pressure‐treated Poultry Products
Authors: Yuste J. , Capellas M. , Pla R. , Llorens S. , Fung D.Y.C. , Mor‐Mur M.
Published: July 2006

ABSTRACT: The recovery of 5 pathogens from minced chicken (MC) and liquid whole egg (LWE) was determined with tryptone soya agar (TSA), selective medium, and thin agar layer (TAL; selective medium overlaid with TSA) to evaluate high‐pressure effects at 200, 300, 400, and 500 MPa for 1 and 5 min at 20 °C. At 400 MPa for 5 min, Escherichia coli inactivation was 4 log in MC and 5.5 log in LWE, whereas no Salmonella Typhimurium, Yersinia enterocolitica, or Listeria monocytogenes were detected in either product. Staphylococcus aureus was the most pressure‐resistant. In general, counts on the 3 media were not different. The TAL method allows differentiation of the inoculated pathogens from background microbiota.
Mixed Cultures of Food‐grade Probiotic Bacteria and Enteric Bacteria Demonstrate Both Synergism and Inhibition of Menaquinone Production
Authors: Parker P. , Jones G. , Smith S.
Published: July 2006

ABSTRACT:The interaction between probiotic (Enterococcusspp.,Lactobacillusspp., andLactococcusspp.) and enteric (Bacteroidesspp.,Escherichia coli, andSalmonellaspp.) bacteria with respect to menaquinone production was examined. Menaquinones were measured in cell pellets by high‐pressure liquid chromatography and the main homologues produced were MIK7–11. The growth of both Bacteroides andE. colicultured with the 3 probiotics was significantly inhibited with concomitant reduction in menaquinone production. The vitamin K status of humans could be affected by consumption of probiotic dairy foods via the contribution made by gut microflora.
Antioxidant Properties of Milled‐rice Co‐products and Their Effects on Lipid Oxidation in Ground Beef
Authors: HIH F. F. S , DAIGLE K. W.
Published: July 2006

ABSTRACT Antioxidant properties were analyzed for methanolic extracts of rice seeds, milled‐rice co‐products, and other selected plant seeds, including cottonseed, soybean, and corn. Values of antioxidant effectiveness ranged from 45% to 86%, based on 100% activity at no change in color during the p‐carotene bleaching test. A correlation exists between the antioxidant activity and the total phenolic content of the rice ingredient extracts (r2 = 0.81). When selected extracts were applied to ground beef, the lipid oxidation was inhibited by, in relative effectiveness, rice hull > rice bran > brown rice. When applied directly to the beef, both defatted brown rice flour and rice bran strongly retarded the lipid oxidation.