bluuebunny/crossref_metadata_2025 huggingface dataset:
Contribution of Cellular Structure to the Large and Small Deformation Rheological Behavior of Kiwifruit
Authors: Rojas A.M. , Delbon M. , Marangoni A.G. , Gerschenson L.N.
Published: July 2006

ABSTRACT: The relative contribution of turgor pressure, cell wall and middle lamellae to the rheology of kiwifruit was studied by performing large deformation assays and using an empirical model proposed by our group. Results were compared with those obtained previously through dynamic testing. Initial (σ0) and residual relaxation (σ∞) stresses determined under 14% constant deformation correlated significantly with complex moduli (G*) and they allowed to detect incipient plasmolysis but not to determine the individual contributions of cell wall and middle lamellae to tissue elasticity. Firmness (Fm) showed no correlation with G* because measurement of failure stress required tissue damage but it was affected by ripening allowing to determine the individual contributions of cell wall and middle lamellae to its value.
Prediction of Process Lethality through Measurement of Maillard‐Generated Chemical Markers
Authors: Wnorowski A. , Yaylayan V.A.
Published: July 2006

ABSTRACT: Direct measurement of time‐temperature exposure of the center of particulate foods is often impractical to establish. Currently, foods are overheated to ensure sterility when their process lethality is difficult to estimate. Indirect measurements using chemical markers can overcome these difficulties. A novel approach that correlates marker yields to process lethality, rather than to microbial destruction, was developed. This was achieved through controlled heating of the sample at various time intervals to further induce marker formation and calculate the lethality values. When the data were plotted as marker yield against lethality and were subsequently extrapolated, the x‐ and y‐axes intercepts yielded information regarding the original process lethality and initial marker yield.
Rheological Properties of Fish Gelatins
Authors: Gudmundsson M.
Published: July 2006

ABSTRACT: The rheological properties of fish gelatins (cod, megrim, tuna, and tilapia) and conventional gelatin (bovine and porcine) were compared. The different fish gelatins had from low to high viscosity values. They also had from low to high gel strength values. However, they had lower melting and gelling temperatures than gels from conventional gelatins. Cold‐water fish gelatins were more different from conventional gelatins than warm water fish gelatins reflecting the different amino acid composition, as cold‐water fish gelatins are low in imino acids. Binary blends of cod and other fish or conventional gelatins seemed to be completely compatible.
In‐Line Measurement of Rheological Parameters and Modeling of Apparent Wall Slip in Diced Tomato Suspensions Using Ultrasonics
Authors: Dogan N. , McCarthy M.J. , Powell R.L.
Published: July 2006

ABSTRACT: Rheological behavior of a slurry consisting of 1‐ to 3‐mm diced tomatoes suspended in tomato juice was evaluated by an in‐line measurement method based upon ultrasonics. This technique permitted the measurements of yield stress, consistency index, and apparent wall slip. The suspension exhibited a yield stress at every flow rate studied, and its value was found to be 0.79 ±0.11 Pa. The shear viscosity at different shear rates was obtained in‐line without assuming a specific constitutive equation. A comparison of Herschel‐Bulkley, Power Law, Bingham Plastic, and Casson models showed that this suspension was best characterized with the Herschel‐Bulkley model. The apparent wall slip region was successfully modeled as a Bingham fluid. This study shows the usefulness of this method for in‐line characterization of particulate tomato products.
Spatial Investigation of the Non‐frozen Water Distribution in Frozen Foods using NMR SPRITE
Authors: Lee S. , Cornillon P. , Kim Y.R.
Published: July 2006

ABSTRACT: Nuclear magnetic resonance (NMR) was used to investigate the spatial distribution of the non‐frozen water in foods during freezing and frozen storage. For samples such as beef, orange juice, and dough, their NMR responses were characterized and studied over temperature and during storage at subzero temperatures. The content of liquid‐like components, such as unfrozen water, was measured in the temperature range between 20 and ‐40 °C. Ice formation led to a significant decrease of the amount of liquid‐like components. This also was gradually diminished during storage, due to slow crystallization. Moreover, 1‐ and 2‐dimensional images of the proton distributions in the frozen samples were obtained by single point ramped imaging with T1 enhancement (SPRITE). The use of SPRITE to examine frozen foods allowed a spatial evaluation of liquid‐like spins during freezing and storage.
Marine Pseudoalteromonas sp. Composes Most of the Bacterial Population Developed in Oysters (Tiostrea chilensis) Spoiled During Storage
Authors: Romero J. , González N. , Espejo R.T.
Published: July 2006

ABSTRACT: To identify bacteria associated with spoilage in oysters, changes in both the load and composition of the bacterial community occurring in storage were followed. Oyster spoilage was accompanied by a 100‐fold increase in the number of CFU. Molecular analysis revealed that a large proportion of the bacteria present in spoiled oysters possessed an intergenic 16S‐23S rDNA spacer of approximately 400 bp. A spacer with the same size was also found in spoiled oysters of different origin and dates of harvest. The bacterial strains containing this spacer may constitute a common cause of the oyster spoilage. These strains were salt‐dependent marine Pseudoalteromonas species and were probably present in oysters before harvest.
Manufacture of Fermented Lactic Beverages Containing Probiotic Cultures
Authors: Oliveira M. N. , Sodini I. , Remeuf R , Tissier J.P. , Corrieu G.
Published: July 2006

ABSTRACT: Lactic beverages (LB) are products prepared with yogurt, whey, and other ingredients; they are popular among consumers in Brazil. LB containing probiotics were manufactured to study bacteria viability and to evaluate product characteristics during shelf life. Although counts decreased, 5.3 × 106 CFU/mL of probiotics in average after 28 d were found. LB behaved as pseudoplastic fluids with thixotropy, and flow curves were best fitted by Oswald‐de‐Waele model. Apparent viscosity and pH decreased slightly with storage. LB showed phase separation increasing until 35% after 14 d, stabilizing after. Finally, microscopy observations showed a dispersion of protein particles. Filamentous and spherical structures corresponded to guar and starch that were added as stabilizers. No differences were noticed between products containing yogurt bacteria and those with probiotics.
Comparison of Commercial Enzymes for the Processing of Marula Pulp, Wine, and Spirits
Authors: Fundira M. , Blom M. , Pretorius I.S. , Van Rensburg P.
Published: July 2006

ABSTRACT: Commercial enzymes were compared in this study to improve the yield and clarification of marula fruit (Sclerocarya berria sub. caffra) juice. An increase in yield of up to 12% in juice treated with the enzyme Rapidase Filtration was recorded. A 15‐fold improvement in juice clarity and an increase in total terpenes were observed after treatment with prefermentation processing enzymes. Post‐fermented marula wine was treated with enzymes to hydrolyze bound monoterpenes. An increase in the free monoterpenes of at least 92% was observed in enzyme‐treated juice. The different enzymes had both positive and negative effects on the flavor of the juice, wine, and distillate. Trenolin Bukett increased the aroma profile of the wine, while it remained closely related to the unaltered marula profile of the control. AR2000 had an overwhelming effect on the flavor profile, but the risk of deviating from the typical marula flavor was high.
Effects of Docosahexaenoic Acid Content in Triacylglycerol on Human Taste Perception
Authors: Koriyama T. , Kohata T. , Watanabe K. , Abe H.
Published: July 2006

ABSTRACT: To elucidate the contribution of docosahexaenoic acid (DHA) in triacylglycerol to tuna oil specific taste effects, suppression of bitterness and enhancement of umami, we conducted sensory analysis employing an oil‐in‐water emulsion prepared with taste substances and the oils differed in the DHA content. The tuna oil specific taste effects were linearly dependent on DHA content. The increase of DHA in oil also linearly enhanced umami and flavor (continuity and richness) of synthetic tuna extract. These results indicate that DHA, a major fatty acid of tuna oil, greatly contributes to tuna oil specific effects on basic tastes and flavor.
Physical and Sensory Characteristics of Reduced‐Fat Breakfast Sausages Formulated With Barley β‐Glucan
Authors: Morin L.A. , Temelli F. , McMullen L.
Published: July 2006

ABSTRACT:Barley β‐glucan, a soluble fiber component, with health benefits, has the potential to be used as a fat replacer in meat systems. Reduced‐fat (12%, w/w) sausages formulated with β‐glucan at 0.3% (w/w) (0.3 β‐gl) and 0.8% (w/w) (0.8 β‐gl) levels were developed and compared to high‐and reduced‐fat controls both sensorially and instrumentally. Compression tests showed 0.3 β‐gl to be similar (p> 0.05) to controls. A trained panel found 0.8 β‐gl to be less firm (p≤ 0.05) than all others, while consumer panelists evaluated 0.3 β‐gl sausages to be acceptable. Raw and cooked sausages contained the same amount of β‐glucan. Findings suggest that reduced‐fat sausages formulated with β‐glucan gum could be a valuable addition to a meat product line.
Rapid Assessment of Rancidity in Complex Meat Products by Front Face Fluorescence Spectroscopy
Authors: Wold J.P. , Mielnik M. , Pettersen M.K. , Aaby K. , Baardseth P.
Published: July 2006

ABSTRACT: Front face autofluorescence from meat products was measured to elucidate the method's ability to measure and predict lipid oxidation. Three sample sets were studied: turkey meat with added aldehydes, raw and heat‐treated turkey meat, and meat loaf at different process steps. Multivariate regression was used to correlate against sensory assessed rancidity, volatile compounds (GC‐MS), and TBARS. Results verified that the increase in fluorescence during storage originates from aldehydes reacting with the meat matrix. Fluorescence modeled sensory assessed rancidity at the same accuracy as volatile compounds (R = 0.9), but was superior to TBARS. Front face fluorescence seems to be a powerful tool for nondestructive analysis of oxidation progress in meat products.
Effect of Paprika (Capsicum annum) on Color of Spanish‐type Sausages During the Resting Stage
Authors: Fernández‐López J. , Pérez‐Alvarez J.A. , Sayas‐Barberá E. , López‐Santoveña F.
Published: July 2006

ABSTRACT: The effects of 3 particle sizes of the mince and 3 paprika concentrations on color parameters (CIELAB color space) of Spanish‐type sausage during the resting stage were studied. The addition of paprika to minced meat reduced lightness. Redness values of minced meat batters with added paprika (30 g/kg) were a result of the paprika they contain, and because the effect of the meat color itself was masked. The contribution of meat yellow components to yellowness values differed with the degree of mincing and increased with coarseness. The effect of paprika on the reflectance spectra of the 3 minces studied was similar and determined the form of the spectrum regardless of the product or processing. Modifications of the color of products containing paprika were due principally to changes which the spice underwent.
Preference Mapping of Domestic/Imported Jasmine Rice for U.S.‐Asian Consumers
Authors: Suwansri S. , Meullenet J.‐F. , Hankins J. A. , Griffin K.
Published: July 2006

ABSTRACT:Three domestic and 12 imported commercial Jasmine rice varieties were evaluated by a trained sensory panel and by 105 Asian families who live in the State of Arkansas. Results showed that consumers preferred imported over domestic products. According to consumers, the sensory characteristics most important to the acceptance of cooked Jasmine rice were, in order of decreasing importance, color, favor, aroma, stickiness, and hardness. Using descriptive data, we evaluated predictive models of Jasmine rice's overall acceptance. These models allowed us to identify important sensory characteristics that encouraged Asian consumers to accept Jasmine rice. Such characteristics included flavor (that is, aroma, aromatics, feeling factors, and aftertaste), texture, and visual attributes. Data collected here could be useful to the U.S. rice industry in developing an understanding of the drivers of Jasmine rice acceptance.
Inactivation Efficiency of Enzymes in Buffered System by Continuous Method with Microbubbles of Supercritical Carbon Dioxide
Authors: Yoshimura T. , Furutera M. , Shimoda M. , Ishikawa H. , Miyake M. , Matsumoto K. , Osajima Y. , Hayakawa I.
Published: July 2006

ABSTRACT: Continuous method with microbubbles of supercritical carbon dioxide (SC‐CO2) was applied to enzyme inactivation in a buffer system, which has a buffer capacity similar to commercial liquid foods (natural juices, fruit drinks, Japanese sake). By continuous treatment with microbubbles of SC‐CO2, α‐amylase and acid protease were effectively inactivated rather than by heat treatments. Compared with the inactivation efficiencies of these enzymes in deionized water by continuous treatment with microbubbles of SC‐CO2, that of α‐amylase was slightly lower, but that of acid protease was not in the buffer system. These results suggest that this method enables the effective inactivation of enzymes, although inactivation efficiency by this method was affected by initial pH and the buffer action of samples.
Free Amino Acid Profiles During Ripening of Port Salut Argentino Cheese After Frozen Storage
Authors: Verdini R.A. , Zorrilla S.E. , Rubiolo A.C.
Published: July 2006

ABSTRACT: Free amino acid profiles of Port Salut Argentino cheeses at different storage conditions (ripening with and without previous frozen storage), ripening times (1, 6, 13, 27, and 56 d), and cheese zones (central and external) were studied. Derivatization with o‐phtaldialdehyde and a C18 column were used for chromatographic separations. Principal component analysis reduced data to 2 dimensions where unripened cheeses (1 to 13 d) were grouped independently of ripening time, sampling zone, and storage condition. Ripened cheeses (27 and 56 d) showed scattering according to ripening time. The contribution of free amino acid profiles to quality in cheeses preserved by frozen storage may be considered similar to that in traditionally ripened cheeses.
Encapsulation of Flavors using Cyclodextrins: Comparison of Flavor Retention in Alpha, Beta, and Gamma Types
Authors: Reineccius T.A. , Reineccius G.A. , Peppard T.L.
Published: July 2006

ABSTRACT: The incorporation and retention on storage of a variety of flavor compounds spray‐dried in a‐, (3‐, and ‐γ‐cyclodextrins (CyDs) was evaluated. CyD/flavor complexes were stored at 20 or 40°C (and 65 or 80% relative humidity), and losses during both the inclusion process and the subsequent storage period were monitored analytically. ‐γ‐CyD generally functioned best in terms of initial flavor retention. On storage, however, losses of volatiles were greatest for γ–CyD and least in the case of α‐CyD. The results suggest that CyD encapsulation via spray‐drying involves matrix entrapment as well as molecular inclusion. CyDs were nonetheless found to stabilize several problematic labile flavor compounds.
Degradation of Mancozeb and Ethylenethiourea in Apples Due to Postharvest Treatments and Processing
Authors: Hwang E.‐S. , Cash J.N. , Zabik M.J.
Published: July 2006

ABSTRACT: Apples sprayed with product label rates of mancozeb in the orchard were used to determine the effectiveness of various wash treatments on the removal of the mancozeb and ethylenethiourea (ETU) on and in fresh and processed apples. Reduction in residual mancozeb and ETU was significantly (p < 0.05) influenced by the effect of various wash treatments as compared to the unwashed samples. There was significantly higher residue in the water‐washed apples than apples processed with chlorine, chlorine dioxide, hydrogen peroxyacetic acid, and ozone washes. We found that certain procedures, such as peeling or steaming, play an important role in reducing pesticide residue levels in processed apples.
Reduction of Heterocyclic Aromatic Amine Formation and Overall Mutagenicity in Fried Ground Beef Patties by Organosulfur Compounds
Authors: Shin H.S. , Rodgers W.J. , Strasburg G.M. , Gray J.I.
Published: July 2006

ABSTRACT: The effects of several organosulfur compounds on heterocyclic aromatic amine (HAA) formation and overall mutagenicity in fried ground beef patties were evaluated. The greatest inhibition of total HAA formation was achieved with diallyl disulfide (78%) and dipropyl disulfide (70%); these compounds also reduced overall mutagenicity by 75 and 65%, respectively. The addition of diallyl sulfide, allyl methyl sulfide, and allyl mercaptan also significantly (p < 0.05) reduced mutagenicity, with reductions of 56, 43, and 30%, respectively. The addition of cysteine and cystine, however, did not reduce the mutagenicity of cooked meat, an observation confirmed by the relatively small reductions in HAA concentrations.
Warmed‐Over Flavor and Lipid Stability of Beef: Effects of Prior Nutrition
Authors: Yang A. , Brewster M.J. , Beilken S.L. , Lanari M.C. , Taylor D.G. , Tume R. K.
Published: July 2006

ABSTRACT: Development of lipid oxidation and warmed‐over flavor (WOF) in cooked meats during refrigerated storage was investigated in beef from pasture‐fed cattle or grain‐fed cattle supplemented with 0, 500, or 2500 IU vitamin E/head/d for 105 d. Meat from pasture‐fed cattle contained as much α‐tocopherol as grain‐fed cattle supplemented with 2500 IU vitamin E, but it was found to be less prone to lipid oxidation and development of WOF. It also contained a higher percentage of linolenic acid and lower content of linoleic acid than grain‐fed beef.
Glass Transition, Water, and Glycerol Effects on Sucrose Inversion in Pullulan‐Sucrose Systems
Authors: Kouassi K. , Roos Y.H.
Published: July 2006

ABSTRACT: Glass transition, water, and glycerol effects on sucrose inversion were investigated in pullulan‐sucrose systems. Pullulan‐sucrose (2:1), PS was dissolved into distilled water. Pullulan‐sucrose‐invertase, PSI, and pullulan‐sucrose‐invertase‐glycerol, PSIG, were prepared by adding tiny amounts of invertase and glycerol, respectively, to similar PS blends. Samples were freeze‐dried, further dehydrated over P2O5, and their physical properties were determined using water sorption isotherms and DSC. The amount of glucose formed by sucrose hydrolysis in samples stored at various RH was monitored. Water and glycerol plasticized the systems. DSC thermograms indicated complex phase behavior in PSI and PSIG depending on water content. Glycerol increased sucrose hydrolysis at 0.538 aw, and favours it even at very moderate aw.
A Comparison of the Effect of Meat Formulation on the Heat Resistance of Free or Encapsulated Cultures of Lactobacillus sakei
Authors: Lemay M.J. , Champagne C.P. , Gariépy C. , Saucier L.
Published: July 2006

ABSTRACT: The protective culture, Lactobacillus sakei Bactoferm‐B2, is not particularly resistant to commercial cooking conditions of meat products. Encapsulation in lyophilized alginate beads supplemented with glycerol was tested as a means to protect L. sakei against heat treatment in broth culture, and in an acidified chicken meat model (pH 5.0). Significantly enhanced (p < 0.05) cell protection by encapsulation was observed in liquid media acidified to pH 5.0 and 5.7, but not in the meat model. Indeed, unencapsulated freezedried cells were significantly more resistant (p < 0.05) in meat. Meat model constituents, such as the binders and meat itself, provided protection to the free cells.
Effects of Carbon Monoxide Packaging on Color and Lipid Stability of Irradiated Ground Beef
Authors: Kusmider E.A. , Sebranek J.G. , Lonergan S.M. , Honeyman M.S.
Published: July 2006

ABSTRACT: The effects of packaging atmosphere (aerobic, vacuum, or modified atmosphere with carbon monoxide) on ground beef treated with ionizing radiation were investigated. Measurements of color (CIE L*, a*, b*), lipid oxidation (TBA value), and sensory quality were conducted during 28 d of storage at refrigerated (0 to 2°C) temperatures. Irradiation significantly (p> 0.001) decreased color scores and increased TBA and off‐odor scores. The MAP + CO treatments increased the L* and a* values (p < 0.001), regardless of irradiation dose. The TBA values for MAP + CO‐packaged samples were well below the levels considered “rancid” (about 1.0). In addition, sensory scores indicated minimal production of irradiation off‐odors with MAP + CO packaging.
Adsorption of Tannins on Lipid Membrane in the Presence of Peptides as Related to Astringency
Authors: Kaneda H. , Watari J. , Takashio M. , Okahata Y.
Published: July 2006

ABSTRACT: stringent reception mechanism of tannins, which has not been fully elucidated, was studied using a lipid‐coated quartz‐crystal microbalance. We found that the adsorption of astringent tannins on the lipid membrane significantly increased in the presence of peptides, while NaCl, tartaric acid, quinine‐sulfite, sucrose, and glutamic acid had no effect. The adsorption of tannin‐peptide complexes showed a linear relationship with tannin concentration and had an optimum concentration of peptides. The adsorption of red wines on the lipid membrane in the presence of bovine serum albumin agreed with astringent intensity in sensory evaluation. It seems that adsorption of tannin‐peptide complexes on the oral lipid membrane could be important to the astringent sensation.
Pectinesterase Inhibitor in Rubbery Banana (Musa sapientum L.)
Authors: Wu M.C. , Tseng K.C. , Huang T.H. , Chang H.M.
Published: July 2006

Pectinesterase (PE) (7 U/mL), extracted from ripe and soft banana flesh (RSBF), was prepared with a ratio of 4 parts (1:4) 2% NaCl. PE activity in the 2% NaCl extracted from homogenized RSBF and rubbery banana flesh (RBF) were 7 and 2 U/mL, respectively, during the 16 h PE extraction, suggesting the existence of the PE inhibitor (PEI) in RBF. Crude PEI extracts from RBF and RSBF exhibited about 80% and 17% inhibitory ratios, respectively, on banana PE activity. Crude PEI from RBF, boiled for 30 to 180 min, showed a 79 to 82% inhibitory ratio of banana PE activity.
Enantiomer Separation of D‐L Branched Amino Acids by Capillary Electrophoresis in Sport Nutritional Supplements
Authors: Boniglia C. , Carratù B. , Sanzini E.
Published: July 2006

A capillary electrophoresis method was developed for the chiral separation of D‐L valine, isoleucine, and leucine. The separation of derivatized amino acids with 9‐fluorenylmethyl‐chloroformate was performed by micellar electrokinetic capillary chromatography. We optimized the method by varying β‐cyclodextrin and sodium dodecyl sulphate concentrations in the presence of 2‐propanol. The proposed method was applied to the determination of D‐forms of valine, Isoleucine, and leucine in the presence of an excess of relative L forms, in commercial supplements for sport nutrition. Results demonstrated that the separation of enantiomers was possible up to an enantiomeric ratio of 1:100. The analysis of selected products confirmed the enantiomeric purity of utilized amino acids.
Determining Washing Conditions During the Preparation of Frozen Surimi from Surubí (Pseudoplatystome Coruscans) Using Response Surface Methodology
Authors: Medina J.R. , Garrote R.L.
Published: July 2006

The effect of process temperature (2 to 18 °C), time (1 to 7 min/ cycle), and water‐mince ratio (2:1 to 8:1) on the quality attributes of surubí (Pseudoplatystoma coruscans) surimi was studied using Response Surface Methodology (RSM). Conditions were identified that allowed to achieve 25% of extracted proteins and a moisture content of 79%, compatible with an acceptable quality of surimi gel. The verification of the prediction models was acceptable. Two cryoprotectant mixtures (sucrose‐sorbitol and maltodextrin‐sorbitol) were also evaluated, with regard to the freezing and frozen storage and the functional quality of the gels. Freezing proved to be an aggressive method, and the 2 mixtures tested showed to be efficient for 6 months of frozen storage.
The Effect of Stunning Methods on Rigor Mortis and Texture Properties of Atlantic Salmon (Salmo Salar)
Authors: Roth B. , Moeller D. , Veland J.O. , Imsland A. , Slinde E.
Published: July 2006

Shear force and rigor mortis were used to evaluate the post‐mortem changes of muscle texture in Atlantic salmon (Salmo salar). The fish were either stunned with carbon dioxide (CO2), electricity, or percussion prior to slaughter. The pre‐mortem stress during CO2 stunning resulted in an earlier onset and resolution of rigor mortis, and accelerated post‐mortem softening of the muscle tissue as compared to the other stunning methods. No significant differences, either in development of rigor mortis or shear force, were seen between fish that were stunned with electricity or by percussion. Consequently electricity can be used for stunning fish prior to slaughter.
Effect of High‐Pressure Processing on Vibrio parahaemolyticus Strains in Pure Culture and Pacific Oysters
Authors: Calik H. , Morrissey M.T. , Reno P.W. , An H.
Published: July 2006

Different strains of Vibrio parahaemolyticus (Vp) in broth cultures and Vp‐inoculated live Pacific oysters (Crassostrea gigas) were subjected to high‐pressure processing (HPP) at 241, 276, 310, and 345 MPa. Results showed Vp numbers were reduced by HPP in both pure culture and whole oysters. Vp inactivation was dependent on time and pressure. Optimum conditions for reducing Vp in pure culture and oysters to nondetectable levels were achieved at 345 MPa for 30 and 90 s, respectively. Resistance variations were detected between Vp in pure culture and in oysters. HPP proved to be an efficient means of reducing Vp in oysters.
Nonenzymatic Browning and Chemical Changes During Grape Juice Storage
Authors: Buglione M. , Lozano J.
Published: July 2006

The effect of storage on juice concentrate from 2 red grape (Merlot and Criolla) and 1 white grape (Yellow Muscat) varieties on color and chemical composition, at temperatures ranging from 10 to 30 °C, was investigated. Color deterioration as A420 occurred at a faster rate in juice made with Merlot variety. The same was true when the pigment destruction as A520/420 was studied. Total reducing sugar, fructose‐to‐glucose ratio, and proline (the only significant amino acid present in grape juice) remained practically constant during storage. The hydroxymethyl‐furfural (HMF) buildup reaction proceeded faster in Criolla grape juice. Independent of variety, a detectable amount of HMF was produced only after 12 wk of storage at any temperature.
Application of Quality Index Method (QIM) Scheme in Shelf‐life Study of Farmed Atlantic Salmon (Salmo salar)
Authors: Sveinsdottir K. , Martinsdottir E. , Hyldig G. , Jørgensen B. , Kristbergsson K.
Published: July 2006

Salmon (Salmo salar) was stored in ice up to 24 d, and changes during storage were observed with sensory evaluation using the Quality Index Method (QIM), and Quantitative Descriptive Analysis (QDA), total viable counts (TVC), hydrogen sulfide (H2S)‐producing bacteria, and instrumental texture measurements (compression test). Maximum storage time in ice was determined with QDA and fat content by Soxhlet extraction. A high correlation between QIM and storage time in ice was found. Storage time could be predicted with ± 2 d. TVC increased exponentially with storage and was dominated by H2S‐producing bacteria after 20 d in ice, which was the maximum storage time. Texture measurements indicated softening of salmon flesh with storage.
Volatile Compounds of Raw Beef from 5 Local Spanish Cattle Breeds Stored Under Modified Atmosphere
Authors: Insausti K. , Beriain M.J. , Gorraiz C. , Purroy A.
Published: July 2006

Volatile compounds of raw beef from Asturiana de los Valles, Morucha, Parda Alpina, Pirenaica, and Retinta cattle breeds were studied. Steaks were packaged under 60% O2, 30% CO2, and 10% N2, and 53 volatile compounds were tentatively identified by purge‐and‐trap extraction and gas chromatography with mass spectrometry after 0, 5, 10, and 15 d of chill storage. The degradation of beef quality with increasing storage time was evidenced by the increase in 2,3,3‐trimethylpentane, 2,2,5‐trimethylhexane, 3‐octene, 3‐methyl‐2‐heptene, 2‐octene, and 2‐propanone and by the decrease in dimethyl sulfide. Consequently, some of the volatile compounds, which are believed to be formed by thermal degradation of meat, might be formed during chill storage, and the rate of formation of some was dependent on the specific compound.
Acceleration of Cheddar Cheese Lipolysis by Using Liposome‐entrapped Lipases
Authors: Kheadr E.E. , Vuillemard J.‐C. , El‐Deeb S.A.
Published: July 2006

ABSTRACT: Two types of lipase (Palatase M and Lipase 50) were encapsulated in liposomes with trapping efficiencies of 35.9 and 40.3%, respectively. The lipases were incorporated into cheese milk at levels of 0.2, 0.5, and 1.0 lipase units/g fat. Treated cheeses had higher moisture and lower protein, fat, and ash contents than the control cheese and they were less firm, but more elastic and cohesive, than the control cheese. Production of free fatty acids was accelerated by the addition of encapsulated enzymes. Cheeses with up to 0.5 lipase unit/g milk fat had slightly better flavor intensities than control cheese. Cheeses with the highest level of Palatase M and Lipase 50 developed a pronounced soapy off‐flavor after 2 and 3 mo of ripening, respectively.
Effect of Antioxidants on the Oxidative Stability of Chicken Breast Meat in a Dispersion System
Authors: Lin C.‐C. , Liang J.‐H.
Published: July 2006

ABSTRACT: The antioxidant efficiency of ascorbic acid, α‐tocopherol, Trolox C, and catechin were evaluated for chicken breast meat in a dispersion system at 37 °C. Peroxidation was induced by adding different kinds of initiators. The initiators exhibited the following order of catalytic action: ascorbic acid/Fe2+ > hemoglobin > Cu+/H2O2 > 2,2′‐azobis (2‐amidinopropane) hydrochloride (AAPH). The antioxidant efficiency of the antioxidants tested depended on their phase distribution and their reactivity to the radicals in various initiation systems. Among the antioxidants tested, catechin was the most effective antioxidant for chicken breast meat oxidation under the experimental conditions.
Effect of Sucrose Ester of Fatty Acid on the Antioxidant Activity of Milk Products on Fish Oil Oxidation
Authors: Shiota M. , Tatsumi K.
Published: July 2006

ABSTRACT: Antioxidant activity of milk products and ingredients were investigated by measuring the induction time of the Rancimat test. Butter serum showed an inhibitory effect of fish oil oxidation in the presence of δ‐tocopherol, which was enhanced by the addition of sucrose ester of fatty acid (SEF). This antioxidant‐enhancing effect was dependent on hydrophilic‐lipophilic balance (HLB) ranging from 1 to 15 of SEF. HLB 2 of SEF enhanced it most effectively. On the contrary, whole milk, skim milk, buttermilk, and whey protein concentrate did not show the inhibitory effect, and these were not improved by SEF.
Inhibition of Modori‐Associated Proteinases by Legume Seed Extracts in Surimi Production
Authors: Ramírez J.A. , García‐Carreño E.L. , Morales O.G. , Sánchez A.
Published: July 2006

ABSTRACT: The modori phenomenon from several fish species has been associated with endogenous proteinolytic enzymes. We evaluated the presence of modori‐associated proteinases in Mexican flounder and Atlantic croaker, and the decrease of the modori effect by inhibition of the responsible enzymes with serine‐proteinase inhibitors from legume seeds. The presence of modori was evaluated by changes in shear stress and shear strain at failure in surimi gels incubated for 30 min at 60 °C. Modori was associated with proteolytic degradation of myosin by SDS‐PAGE analysis. Crude extracts from kidney bean, pea, chickpea, lentil, and soybean inhibited proteolytic activities of both fish to different extents.
Quantitative Analysis on 2‐Acetyl‐1‐pyrroline of an Aromatic Rice by Stable Isotope Dilution Method and Model Studies on its Formation during Cooking
Authors: Yoshihashi T.
Published: July 2006

A quantitative analysis of 2‐acetyl‐1‐pyrroline from aromatic rice samples using a stable isotope dilution method was developed. The compound was extracted from seedlings, roots, and husks at room temperature for 2 h, whereas milled or brown rice samples were extracted at 75 °C. The recovery of 2‐acetyl‐ 1‐pyrroline was linear from 5 to 5000 ng/g with sensitivity of less than 0.1 ng/g. 2‐Acetyl‐1‐pyrroline showed tautomerism with animide form. The results revealed that 2‐acetyl‐1‐pyrroline present in aromatic rice samples did not form during cooking or postharvest processes.
Preparation and Characterization of Hydrolyzed Proteins from Defibrinated Bovine Plasma
Authors: Wanasundara P.K.J.P.D. , Amarowicz R. , Pegg R.B. , Shand P.J.
Published: July 2006

ABSTRACT: Proteins from defibrinated bovine blood plasma were enzymatically hydrolyzed with food‐grade microbial proteases Alcalase 2.4 L® and Flavourzyme L&TM;, and a substrate consisting of small peptides and free amino acids was obtained. Hydrolysis of the plasma proteins with Flavourzyme resulted in a maximum degree of hydrolysis of 43% at an enzyme concentration of 110 LAPU/g protein after 15.5 h of hydrolysis. Among the free amino acids in the hydrolysate, hydrophobic amino acids were predominant. The major plasma proteins were degraded due to hydrolysis; peptides of less than 1.04 kDa were dominant in the product when a high degree of hydrolysis was employed.
Inactivity of μ‐Calpain Throughout Postmortem Aging of Meat
Authors: Kanawa R. , Ji J.‐R. , Takahashi K.
Published: July 2006

ABSTRACT: In order to determine the involvement of μ‐calpain in the tenderization of meat during postmortem aging, μ‐calpain was prepared from porcine skeletal muscle and its activity was measured under various conditions, using casein and myofibrils as the substrate. μ‐Calpain was inactive at pH 5.89 and below 15 °C. Even when the reaction time was extended to 10 h, it was entirely inactive at pH 5.62 and 5 °C. In the early postmortem stage, when the pH value of muscle is above 6.0, μ‐calpain was considered to be inactive due to the low concentration of sarcoplasmic calcium ions. μ‐Calpain is, therefore, irrelevant to the tenderization of meat throughout postmortem aging.
Rheological Characterization of Skim Milk Stabilized with Carrageenan at High Temperatures
Authors: Anderson A.D. , Daubert C.R. , Farkas B.E.
Published: July 2006

ABSTRACT: Superpositioning principles were applied twice to model temperature (25 to 125 °C) and concentration (0.005 to 0.040% w/w) effects on skim milk and carrageenan solutions. Samples were analyzed using a controlled stress rheometer equipped with a pressurized sealed cell, permitting measurements well above standard boiling conditions. Individual samples were sheared between 10 and 160 s−1, and predictive equations were developed to predict Newtonian viscosity as a function of temperature and carrageenan concentration. The superpositioning technique coupled with advancements in rheological instrumentation permits high temperature measurements and offers a strategy for viscosity determination for thermal processing unit operations.
Aqueous Extraction and Membrane Isolation of Protein from Defatted Gevuina avellana
Authors: Moure A. , Rua M. , Sineiro J. , Dominguez H.
Published: July 2006

ABSTRACT: Proteins from defatted Gevuina avellana seeds were extracted in aqueous media. Protein extraction was limited at liquid‐to‐solid ratios under 12 g/g, but was not significantly affected by temperatures in the 25 to 45 °C range. The maximum protein extractability occurred both at acidic and alkaline pH; the presence and concentration of NaCl affected it differently, depending on the extraction pH. Up to 3 extraction stages with whey recycle after ultrafiltration were performed, without affecting the protein extraction yield. The functional properties of the protein isolated with membranes were similar or better than those from isoelectric precipitation.
Structural Details in Soybeans: A New Three‐dimensional Visualization Method
Authors: Kuensting H. , Ogawa Y. , Sugiyama J.
Published: July 2006

ABSTRACT: A new combination of sample preparation, imaging and image processing techniques allowing new insights into the structure of biological objects has been developed as a method for the visualization and quality evaluation. This method is for the first time transferred to soybeans (Glycine soja L.) of the Nattousyoryu variety as an example of food and agricultural produce using volume rendering of thin slice microscopy images. By this method, soybeans are displayed as three‐dimensional data representations for visualization. Internal structures like the dormant cotyledon leafs are visualized and highlighted.
Gelling Properties of Egg White Produced Using a Conventional and a Low‐shear Reverse Osmosis Process
Authors: Eleya M.M. Ould , Gunasekaran S.
Published: July 2006

ABSTRACT: Gelling properties of heat‐induced egg white (EW) powders obtained using a conventional (control) and a reverse osmosis (RO) process were investigated under different pHs (3–9) and protein concentrations (5–20%) by dynamic and uniaxial compression rheological tests. At pH 9, temperature sweep tests indicated that gelation behavior of RO and control samples were similar. Both gelation temperature and G′ were concentration‐dependent; the increase in G′ with concentration followed a power‐law relationship with an exponent of 2.42. Failure stress and strain of cured gels were concentration‐ and pH‐ dependent but were not significantly (p = 0.05) different for the two powders. Results suggest that gelling properties of EW powders are not significantly affected by the RO treatment.
Physicochemical Properties of Wheat Flour Dough Modified by Microbial Transglutaminase
Authors: Tseng C.‐S. , Lai H.‐M.
Published: July 2006

ABSTRACT: In this study, microbial transglutaminase (MTGase) was employed to modify viscoelasticity of wheat flour dough. Three flours, namely In‐, Mid‐, and Out‐flour derived from different parts of wheat kernel, were used. When adding 16 ppm MTGase, the maximum resistance to extension (Rmax) of In‐(58%), Mid‐(56%), and Out‐flour(52%) doughs, prepared at specific water levels indicated in parentheses, is increased by 51%, 35%, and 77%, respectively. The extensibility (E) of these 3 doughs is reduced by 16%, 11%, and 6%; the stickiness is also lowered by 12%, 5%, and 22%, respectively. SDS‐PAGE analysis indicates that crosslinks occur within wheat gluten of MTGase‐treated dough.
Effect of Lactic Acid Bacterial Fermentation on the Characteristics of Minced Mackerel
Authors: Yin L‐J , Pan C‐L , Jiang S‐T
Published: July 2006

ABSTRACT: To improve the functionality and quality of seafood, mackerel minces were fermented with lactic acid bacteria (LAB) ∼Lactobacillus plantarum CCRC10069, Lactococcus lactis subsp. lactis CCRC 12315, Lactobacillus helveticus CCRC 14092, or their combination at 37 °C. Rapid growth of LAB, decline in pH, suppress of main microflora, increases in whiteness, Hunter L, nonproteinous nitrogen, sensory quality, and free amino acids related to taste were observed. However, VBN of samples fermented with LAB were still d ≤ 25 mg/100g after 36 h fermentation. SDS‐PAGE indicated the obvious degradation of water‐ and salt‐soluble muscle proteins after 12 h fermentation. Animal test demonstrated the LAB‐fermented mince has the functionality on reduction of blood pressure, glucose, and total cholesterol of SHR.
Microbial Inactivation in Meat Products by Pressure/Temperature Processing
Authors: López‐Caballero M.E. , Carballo J. , Jiménez‐Colmenero R
Published: July 2006

ABSTRACT: The purpose of this study was to analyze the effect of combined treatments of high pressure (300 MPa, for 15 min) and temperature (5, 20, 35, and 50 °C) on microbial inactivation (total bacteria count, lactic acid bacteria, Baird Parker flora, Pseudomonas sp., and enterobacteria) and color in sliced cooked ham and ground pork patties. Microbial reduction due to the pressure/temperature treatments was higher in pork patties. Greater pressure‐induced loss viability was observed in gram‐negative bacteria. Microbial inactivation was more pronounced when pressurization was applied at 50 °C. Microbial sensitivity to the high pressure treatment was conditioned by the processing temperature, the microorganism group, and the type of meat product.
Copper Metabolism in Rats Fed Diets Containing Maillard Reaction Products
Authors: Delgado‐Andrade C. , Seiquer I. , Navarro M.P.
Published: July 2006

ABSTRACT: Equimolar mixtures ofglucose/lysine (GL) orglucose/methionine (GM) (both 40% moisture) were heated (150 °C, 30 and 90 min) to prepare the samples: GL30, GL90, GM30 and GM90. Copper balance and concentration in some organs was determined in rats fed 5 diets: control diet and diets containing 3% of the samples. Comparisons with respect to the control group were as follows: Fecal Cu excretion decreased in GM groups, and urinary excretion in all groups. Copper absorption, retention, and the efficiency of both processes increased in all groups except GM30. Copper concentrations were significantly higher in spleen, kidney, and skin in the GM90 group. Kidney Cu concentration was higher in the GM30 group. Adding GL and GM samples to a balanced diet increased copper absorption and retention, and copper accumulated in some organs.
Effects of Calcium Chloride‐based Prefreezing Treatments on the Quality Factors of Strawberry Jams
Authors: Suutarinen J. , Honkapää K. , Heiniö R.‐L. , Autio K. , Mustranta A. , Karppinen S. , Klutamo T. , Llukkonen‐Lllja H. , Mokkila M.
Published: July 2006

ABSTRACT: Vitamin C contents of pretreated strawberries did not change during 2 mo of freezing, but after jam cooking and storage, the vitamin C contents of all the studied jams decreased dramatically. Jams made from strawberries treated with CaCl2 and PME in a vacuum had the highest firmness compared to the reference or other pretreated jam strawberries (p < 0.05). According to sensory evaluation of the jams, different prefreezing treatments were shown to have a significant influence on the sensory attributes evaluated (p < 0.001), the only exception being the redness of color after 4 mo storage.
Effects of Pseudomonas putrifaciens and Acinetobacter spp. on the Flavor Quality of Raw Ground Beef
Authors: Chung M.S. , Lee J.H. , Min D.B.
Published: July 2006

ABSTRACT: Beef stored under light had higher TBA values and more volatile compounds than beef in the dark for 8 d at 4 °C (P < 0.05). Beef inoculated with Acinetobacter species had more bacterial growth, better acceptable sensory score, and fewer volatile compounds than beef inoculated with Pseudomonas putrifaciens (P < 0.05). Even though the growth of Acinetobacter spp. was 74 times more than that of Pseudomonas putrifaciens, the TBA values with Acinetobacter spp. increased only 60% of that with Pseudomonas putrifaciens after 8 d. Types of bacteria seem to be more important in lipid oxidation than numbers.
Effect of Sugar and Nitrogen on the Production of Anthocyanin in Cultured Carrot (Daucus carota) cells
Authors: Narayan M.S. , Venkataraman L.V.
Published: July 2006

ABSTRACT: Callus cultures of carrot, Nentes scarlet ‐ 104 variety, were initiated on MS medium for anthocyanin production. Two anthocyanins, cayanidin‐3‐lathyroside and cyanidin‐3‐glucoside, PRESENT in the ratio of 3:1, were identified in the callus cultures. Eight sugars were tried as carbon source for the production of total anthocyanin. The sugars xylose and lactose, although they initiated growth of the green callus, did not initiate anthocyanin pigmentation. Fructose, galactose, and maltose produced less than 1.75% (dry weight basis) anthocyanin though there was growth of the pigmented callus. Glucose and sucrose produced 3.5%. It was observed that 7.5% sucrose in the medium produced maximum amount of anthocyanin (6.5%). Total nitrogen at 70 mM concentration and a 1:4 ratio of ammonium to nitrate yielded maximum cell growth and best anthocyanin production. Modifying the medium it was possible to enhance the production to 6‐8%.
Characterization of Polysaccharide and Volatile Compounds Produced by Kefir Grains Grown in Soymilk
Authors: Liu J‐R. , Chen M‐J. , Lin C‐W.
Published: July 2006

ABSTRACT: The characteristics of polysaccharides isolated from milk and soymilk kefir grains, and the composition of flavor and volatile compounds from soymilk kefir were investigated. Soymilk kefir grains revealed lower polysaccharide content than milk kefir grains, with a polysaccharide profile consisting primarily of glucose and galactose, with the former predominating. The apparent molecular weight of the polysaccharide was estimated at 1.7 × 106 Da. In comparison to nonfermented soymilk, the concentrations of the key volatile compounds for soymilk kefir (such as acetaldehyde, acetone, diacetyl, and ethanol) increased, while n‐hexanal concentration decreased. The acetaldehyde level for soymilk kefir was slightly higher, but levels for the other volatile compounds were lower than for milk kefir.
Emulsifying Properties of Whey Protein‐Carboxymethylcellulose Complexes
Authors: Girard M. , Turgeon S.L. , Paquin P.
Published: July 2006

ABSTRACT: Proteins/polysaccharides complexes could improve emulsifying properties of proteins by thickening the layer at the interface of the oil droplets. Emulsifying properties of whey protein‐carboxymethylcellulose complexes (WPI/CMC) were compared with those of a whey protein isolate (WPI). Ingredients were incorporated into oilinwater emulsions with various protein and oil contents. Visual observations, protein load, protein distribution and rheological measurements were used to evaluate emulsion stability. Protein load up to 26.1 and 48.9 mg protein/g oil were obtained for WPI and WPI/CMC emulsions, respectively. The higher protein load of WPI/CMC emulsions and visual observations indicated that WPI/CMC complexes had greater emulsifying properties against coalescence than whey proteins. However, complexes enhanced flocculation of oil droplets.
Effect of Freezing and Frozen Storage on Chemical and Microbiological Characteristics in Sheep Milk Cheese
Authors: Tejada L. , Sánchez E. , Gómez R. , Vioque M. , Fernández‐Salguero J.
Published: July 2006

ABSTRACT: Most chemical components and water activity of an the Los Pedroches' brand ewes' milk cheese were not altered by frozen storage. Lactic acid concentration and pH were significantly different (p < 0.05) in control cheeses and those kept in frozen storage for 3 and 6 months from those stored for 9 months. Proteolysis continued slowly during frozen storage, with significantly higher rates of non protein nitrogen and amino acid nitrogen (p < 0.05) present at the end of the storage period. Counts of microorganisms, except for enterococci, tended to decrease during frozen storage. Freezing rates did not affect the chemical and microbiological characteristics studied.
Lipase‐Assisted Concentration of n‐3 Polyunsaturated Fatty Acids from Viscera of Farmed Atlantic Salmon (Salmo salar L.)
Authors: Sun T. , Pigott G.M. , Herwig R.P.
Published: July 2006

ABSTRACT: In fish processing, viscera are generally considered waste products and often discarded. Our research objective was to use Atlantic salmon (Salmo salar L.) viscera as a source of fish oil and to increase its concentration of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by lipase‐assisted hydrolysis. Lipids from fillets and viscera had similar fatty acid compositions. After the enzymatic hydrolysis, acylglycerols were isolated from free fatty acids, therefore increasing the concentrations of EPA and DHA in the acylglycerols. Among the 6 commercial lipases investigated, lipases from Pseudomonas cepacia and Candida rugosa were the most effective following incubation of viscera oil at 35 °C for 20 h. Salmon viscera were a good source for fish oil, and the concentration of DHA and EPA was doubled by using microbial lipases.