bluuebunny/crossref_metadata_2025_split huggingface dataset:
Degradation Kinetics of Chlorophyll in Peas as a Function of pH
Authors: Ryan‐Stoneham T. , Tong C.H. 
Published: July 2006

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

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

ABSTRACT Myofibrils, oxidized with FeCl3/H2O2/ascorbate, exhibited an increase in carbonyls and amines, SH→SS conversion, peptide scission, myosin polymerization, and a decrease in thermal stability and gel‐formation ability. Amino‐acid side chains of whey‐protein isolates (WPI) and soy‐protein isolates (SPI) were also modified during oxidation, but the thermal stability of WPI or SPI was not significantly altered. Oxidation increased elasticity of SPI gel but not that of WPI gel. Similarly, oxidation promoted interactions of myofibrils with SPI but not with WPI, resulting in > 30% increases in elasticity of the myofibril/SPI composite gel over its nonoxidized control. Hence, in processed meats where oxidation occurs, the presence of soy proteins may enhance the functionality of myofibrillar proteins.
Decolorization of Brown Pigments in Foods by Immobilized Mycelia of Coriolus versicolor IFO 30340 and Paecilomyces canadensis NC‐1
Authors: Terasawa N. , Murata M. , Homma S. 
Published: July 2006

ABSTRACT Three microorganisms were cultured to investigate their decolorizing activity on mixtures of 2 types of model brown pigment and 2 types of browned food. The mixture of model brown pigments of the Maillard reaction type and phenol type was not decolorized by cultivation with Coriolus versicolor IFO 30340, but it was decolorized by Paecilomyces canadensis NC‐1 and by Streptomyces werraensis TT 14. The immobilized mycelia of C. versicolor IFO 30340 and P. canadensis NC‐1 were incubated simultaneously or successively with each mixture of 2 types of browned food. It was found that the mixed culture of these 2 mycelia showed a higher decolorization rate than their successive culture.
Nisin‐resistant (Nisr) Listeria monocytogenes and Nisr Clostridium botulinum Are Not Resistant to Common Food Preservatives
Authors: MAZZOTTA A.S. , MODI K. , MONTVILLE T.J. 
Published: July 2006

ABSTRACTNisin‐resistant (Nisr) strains of Clostridium botulinum and Listeria monocytogenes may arise as nisin becomes more widely used as an additional safety barrier in minimally‐processed foods. The sensitivity of Nisr L. monocytogenes ATCC 700301 and ATCC 700302 and toxigenic Nisr C. botulinum 169B to low pH, salt, sodium nitrite, and potassium sorbate was assayed using discontinuous gradients in broth and compared to the parental wild‐type strains. The nisin‐resistant strains did not have intrinsic resistance to low pH, sodium chloride, potassium sorbate, or sodium nitrite. In no case were the Nisr L. monocytogenes and C. botulinum strains examined more resistant to inhibitors than the parental strains.
Flavor Manipulation Can Enhance the Impression of Fat in Some Foods
Authors: YACKINOUS C. , GUINARD J.‐X. 
Published: July 2006

ABSTRACTThe objective of this study was to investigate the effects of fat and flavor (aroma) on the sensory impression of fat. One hundred and six naive subjects rated 4 food systems varying in fat and flavor content (prepared according to a factorial design) for fattiness first without and then with nose clips, and for liking. On average, subjects gave higher fatty scores to the high fat samples. There was a significant effect of flavor concentration on the fattiness ratings without the nose clips; however the effect was product specific. The nose clips significantly reduced the fattiness ratings for all products (p < 0.001), indicating that the flavor components of fat‐based foods can influence fat perception.
Hydrolytic and Oxidative Changes in the Lipids of Chicken Breast and Thigh Muscles During Refrigerated Storage
Authors: Alasnier C. , Meynier A. , Viau M. , Gandemer G. 
Published: July 2006

ABSTRACT:The changes in free fatty acid (FFA) amount and composition and in Thiobarbituric acid reactive substances (TBARS) were simultaneously determined in chicken breast and thigh muscles at intervals between 1 and 14 d of storage at 4 °C (1, 3, 7, 10, 14). The rates of lipid hydrolysis were fast in the first 3 d and then slowed until day 14; phospholipids showed the same pattern but hydrolysis of triacylglycerols was linear at least in thigh muscles. Oxidation increased linearly during storage. Thigh muscles contained 3 times more FFAs than breast muscles and 2 to 4 times less TBARS suggesting that lipolysis did not favor lipid oxidation although both increased concomitantly.
Purification and Kinetic Characterization of Peroxidase from Tomato Cultivated under Different Salinity Conditions
Authors: Rodríguez‐López J.N. , Espín J.C. , Tudela J. , Martínez V. , Cerdá A. , García‐Cánovas F. 
Published: July 2006

ABSTRACT:By including hydrophobic chromatography in the purification scheme, 2 homogeneous tomato fruit peroxidase isoenzymes were obtained. The expression of these 2 peroxidases, one acid and the other basic, was determined in tomato fruits grown under different salinity conditions. Increased salinity modified the isoenzyme profile of tomato peroxidase. In tomatoes grown under highly saline conditions, there was an increase in the expression of the acid form with respect to the basic, the acid/basic ratio rising from 4.5 in tomatoes grown under normal saline conditions to 70 in those grown in highly saline conditions. Kinetic studies using 2,2′‐azinobis(3‐ethylbenzo‐thiazolinesulfonic acid) as reducing substrate showed that increased salinity in the growth medium did not modify the kinetic parameter of tomato peroxidase over both hydrogen peroxide or reducing substrate.
Changes in Selected Chemical Quality Characteristics of Channel Catfish Frame Mince During Chill and Frozen Storage
Authors: Suvanich V. , Jahncke M.L. , Marshall D.L. 
Published: July 2006

ABSTRACT:Changes in total volatile base nitrogen (TVBN), pH, salt soluble protein (SSP), moisture content, and expressible moisture of channel catfish frame mince during storage at ‐20, 0, and 5 °C were investigated. Refined mince was either unwashed or washed twice, with mince designated for frozen storage mixed with cryoprotectant. TVBN increased during refrigerated storage, while SSP decreased during frozen storage. Expressible moisture increased during frozen storage but not during refrigeration storage temperatures. Moisture content and pH of mince did not change during storage. Results indicate that mince should be stored for no longer than 3 d at 0 or 5 °C to maintain optimal quality. Frozen mince with cryoprotectant would remain acceptable for at least 3 months at ‐20 °C.
Biological Characteristics Affect the Quality of Farmed Atlantic Salmon and Smoked Muscle
Authors: GÓMEZ‐GUILLÉN M.C. , MONTERO P. , HURTADO O. , BORDERÍAS A.J. 
Published: July 2006

ABSTRACT:Various biological characteristics influencing the quality of farmed salmon and smoked muscle were studied. No great differences in proximate composition were observed among raw fish. Stress produced a slight decrease in protein solubility at 0.8 M NaCl and also slight variations in electrophoretic profile. This was accompanied by a certain degree of muscle softening. Thirty‐days starvation produced slight depletion of the sarcoplasmic fraction, collagen insolubilization, and muscle hardening. The effect of triploidy was more evident in sea‐caged fish, resulting in lower protein solubility at 0.05M NaCl and lower insoluble collagen than diploids. After smoking, protein solubility at 0.8M NaCl was highest in stressed fish, and non‐starved fish collagen became insolubilized.
High Oxygen and High Carbon Dioxide Modified Atmospheres for Shelf‐life Extension of Minimally Processed Carrots
Authors: Amanatidou A. , Slump R.A. , Gorris L.G.M. , Smid E. J. 
Published: July 2006

ABSTRACT:The impact of high O2+ high CO2 modified atmospheres (MA), on the preservation of minimally processed carrots was studied. A combination of 50% O2+ 30% CO2 prolonged the shelf life of sliced carrots compared to storage in air by 2 to 3 d. When the carrots received a pre‐treatment with a 0.1% citric acid dip and a sodium alginate edible coating prior to packaging, shelf life was extended by 5 to 7 d. Advantages and disadvantages of the proposed MA over previously recommended MA (1% O2+ 10% CO2), related to a range of physicochemical and microbiological characteristics of carrots are discussed.
Drying Kinetics of Hydrated and Gelatinized Corn Starches in the Presence of Sucrose and Sodium Chloride
Authors: Uzman D. , ŞAhbaz F. 
Published: July 2006

ABSTRACT:Drying behavior of the hydrated corn starch, hydrated starch/sucrose, and hydrated starch/sodium chloride mixture and their gels were investigated. Drying data were obtained on slabs of samples in a laboratory tunnel dryer at 40 to 70 °C. The rate‐of‐drying curves for hydrated starches with or without sucrose showed that the moisture movement may be the result of capillary action rather than diffusion. In the hydrated starches containing sodium chloride, case‐hardening was the controlling mechanism. In gelatinized samples, however, diffusion was the main mechanism. The effective diffusivity was estimated by the methods of slopes. Gelatinization of starch reduced the moisture diffusivity significantly. The presence of sucrose or sodium chloride decreased the coefficient significantly in hydrated starch, but their effect was small in gelatinized samples.
Physical Characteristics and Microstructure of Reduced‐fat Frankfurters as Affected by Salt and Emulsified Fats Stabilized with Nonmeat Proteins
Authors: Su Y.K. , Bowers J.A. , Zayas J.F. 
Published: July 2006

ABSTRACT:Functional properties and microstructure of frankfurters containing 1.5% or 2.5% salt and 15% pre‐emulsified fat (PEF) stabilized with 2% pea protein, soy protein, or sodium caseinate were studied. With the exception of frankfurters with pea protein and 1.5% NaCl, all the others made with PEF” had greater (p < 0.01) thermal stability than all‐meat frankfurters. Frankfurters containing soy protein or sodium caseinate had greater (p < 0.01) shear force than those with pea protein. Reducing NaCl in the frankfurters containing PEF did not influence the shear force. Microstructure examination revealed that many fat globules were entrapped physically within soy protein or sodium caseinate, which stabilized the meat emulsions and contributed to a firmer texture. Key Words: emulsified fat, reduced‐fat, low‐salt, microstructure, frankfurters
Extending Shelf Life of Fresh‐cut Pears
Authors: Dong X. , Wrolstad R.E. , Sugar D. 
Published: July 2006

ABSTRACT:The effects of various treatments were evaluated for extending shelf‐life of fresh‐sliced pears. Sliced Anjou pears had browning‐free color for 30 d by dipping with 1.0% ascorbic acid and 1.0% calcium lactate, but texture was soft with juice leakage. The combination treatment of 0.01% 4‐hexylresorcinol (4‐HR), 0.5% ascorbic acid and 1.0% calcium lactate can provide 15 to 30 d shelf‐life for Anjou, Bartlett, and Bosc pears when the pears are sliced at an average ripeness of 43, 49, and 38 Newton respectively, with 2 min dipping, partial vacuum packaging, and 2 to 5 °C storage. 4‐HR residual content ranged from 1 to 7 ppm after 14 d storage. Panelists could detect a flavor difference between 0.01% 4‐HR treated pears and controls.
Physicochemical and Sensory Characteristics of Fish Gelatin
Authors: Choi S.‐S. , Regenstein J.M. 
Published: July 2006

ABSTRACT:The physicochemical differences between pork and fish gelatin and the effect of melting point on the sensory characteristics of a gelatin‐water gel were investigated. Gelatin gel strength (measured as Bloom) and melting point of gelatin gels were measured, and quantitative descriptive analysis sensory tests were performed. The dependence of the gelatin gel strength and the melting point of fish gels on gel concentration, maturation time, maturation temperature, pH, and the influence of NaCl and sucrose were similar to those for pork gelatin. The flavored fish gelatin dessert gel product had less undesirable off‐flavor and off‐odor and a more desirable release of flavor and aroma than the same product made with an equal Bloom, but higher melting point, pork gelatin.
Aluminum Content in Foods and Beverages Consumed in the Spanish Diet
Authors: López F.F. , Cabrera C. , Lorenzo M.L. , López M.C. 
Published: July 2006

ABSTRACT:A reliable and rapid method for determining aluminum content in foods and beverages was developed using electrothermal atomization‐atomic absorption spectrometry (ETA‐AAS) using previous optimization of the time‐temperature program for the graphite furnace. The samples were subjected to acid mineralization with HNO3 and V2O5. The technique used slurries for assay in samples of dairy products. The detection limit was 4.0 pg. The mean recovery obtained ranged from 98.5% to 99.0%. The variation coefficient ranged from 3.2% to 5.2%. The results obtained ranged from 1.362 to 6.610 μg/g in seafood, 0.171 to 29.688 μg/g in vegetables, 19.560 to 70.100 μg/g in olive oil, 0.424 to 6.430 μg/g in dairy products and 25.600 to 58.057 μg/g in stimulant drinks and infusions. This study contributes new data on the Al content of a variety of foods and beverages in Spain and such data are important for composition tables. The higher presence corresponded to seafood, vegetables and dairy products. Their contribution to Al dietary intake were estimated.
Enzymatic Hydrolysis and Synthesis of Soy Protein to Improve its Amino Acid Composition and Functional Properties
Authors: de la Barca A.M. Calderón , Ruiz‐Salazar R.A. , Jara‐Marini M.E. 
Published: July 2006

ABSTRACT:Soy protein was enzymatically modified and ultrafiltred, and functional properties were evaluated. After enzymatic hydrolysis, hydrolysate (20 g/100 mL) was incubated with chymotrypsin and glycerol at 37°C. Different methionine methyl‐ester concentrations, pHs, and time were tested. Amino acid composition and functional properties of ultrafiltrated fractions (FI>10, 10>FII>3, and 3>FII>1 kDa) were evaluated. Optimum hydrolysis conditions were 12 h and 50°C, and those of synthesis were 0.07585 g Met/g, pH 7, and 3 h, binding 2.2% to 5% methionine. Fractions under 10 kDa presented 100% solubility and the best clarity. High‐methionine fractions had higher foam volume, lower emulsifying capacity and hydrophobicity. Modified hydrolysates have a potential for use in soluble high nutritional products.
Heat and Moisture Transfer and Hygrophysical Changes in Elastoplastic Hollow Cylinder‐food During Drying
Authors: Akiyama T. , Hayakawa K. 
Published: July 2006

ABSTRACT:There are many dried foods of hollow cylinder‐shapes in the market. Hygrostress cracks form in these foods during drying without a careful process control. The objective of the present work was to develop a simulation method for heat and moisture transfer in hollow cylinder‐food coupled with hygrophysical changes. A modified Luikov's model was used for the development together with a virtual work minimization principle, critical tensile stress criterion for crack formation, and critical crack‐tip‐opening angle criterion for crack propagation. The developed, computerized simulation model was validated through drying experiments of samples made from a starch hydrate.
Early Postmortem Detection of Exudative Pork Meat Based on Nucleotide Content
Authors: Batlle N. , Aristoy M.‐C. , Toldrá F. 
Published: July 2006

ABSTRACT:The content of nucleotide metabolites in the muscle L. dorsi was analyzed for the detection of pale, soft and exudative (PSE) pork meats at just 2 h postmortem. PSE meat was characterized by significantly lower (p < 0.05) amounts of adenosine 5′‐triphosphate (ATP) and higher adenosine 5′‐monophosphate (AMP), inosine 5′‐monophosphate (IMP), inosine (ino) and hypoxanthine (hyp) than normal meat. IMP and ino classified all the samples from both groups with statistical significance (p < 0.05). The K0 value, R′ value and IMP/ATP ratios were also useful indicators for full distinction of PSE meats. Thus, the assay of any of these nucleotide metabolites may allow a good detection of PSE meats at very short, only 2 h, postmortem time.
Extracting Conditions for Megrim (Lepidorhombus boscii) Skin Collagen Affect Functional Properties of the Resulting Gelatin
Authors: Montero P. , Gómez‐Guillén M.C. 
Published: July 2006

ABSTRACT:Various procedures for extracting collagen and/or gelatin from megrim skins were compared on the basis of gelatin functional properties. It was possible to prepare a dry powder of soluble collagen with good viscoelastic and gelling properties, which can be converted into gelatin by dissolving at temperatures above 45 °C. Physical properties of gelatins are influenced more by extracting conditions than by imino acid composition. A high‐quality, readily‐dissolved gelatin was obtained from megrim skins using a pretreatment of the skins with NaCl and dilute NaOH, then swelling with 0.05 M acetic acid followed by an extraction step in water at 45 °C.
Optimizing Apple Juice Extraction in Multiple Presses
Authors: González M.T. , Elustondo M.P. , Urbicain M.J. 
Published: July 2006

ABSTRACT:A method was developed to find the optimum hydration flow sheet that maximizes either the profit or the soluble solids recovery for a given number of presses in an apple concentrate juice plant. The pomace arising from a press can be wetted with either pure water or dilute juice from downstream presses, or a mixture of both in any proportion. The mass balance around the presses involving any hydration arrangement was posed as an array named connectivity matrix. The connectivity matrix and the economical balance were written in computer code in order to carry out the optimization procedure. The optimization started from a minimum amount of water, and stepwise increasing levels of hydration were evaluated. The best value of this combinatorial search was retained. The optimum arrangement was pure countercurrent in most of cases considered.
Apple Wraps: A Novel Method to Improve the Quality and Extend the Shelf Life of Fresh‐cut Apples
Authors: McHugh T.H. , Senesi E. 
Published: July 2006

ABSTRACT:A novel method was developed to extend the shelf life and improve the quality of fresh‐cut produce. Edible coatings and films were made from apple puree with various concentrations of fatty acids, fatty alcohols, beeswax, and vegetable oil. Apple pieces were coated with solutions or wrapped in preformed films. Changes in moisture content and color were measured during storage. Increasing concentrations of lipids significantly improved the moisture barrier properties of films. Water vapor permeability varied from 69 to 325 g mm/kPa d m2. Apple‐based wraps significantly reduced moisture loss and browning in fresh‐cut apples. Color was preserved for 12 d at 5 °C. Wraps were significantly more effective than coatings.
Changes in Temperature, Texture, and Structure of Konnyaku (Konjac Glucomannan Gel) During High‐pressure‐freezing
Authors: Teramoto A. , Fuchigami M. 
Published: July 2006

ABSTRACT:To determine the effects of high‐pressure‐freezing, changes in temperature, texture, and structure of konnyaku (a gel with high water content) were measured during freezing for 60 min at 0.1 to 700 MPa and ‐20 °C. During freezing at 0.1, 100, 500, 600, and 700 MPa, exothermic peaks were detected (konnyaku froze). However, at 200 to 400 MPa, exothermic peak was not detected and temperature rose when pressure was released at ‐20 °C; the supercooled konnyaku froze by pressure‐shift‐freezing. The coarse gel network observed in unfrozen konnyaku was compressed by freezing due to formation of ice crystals. The rupture stress increased and strain decreased in all frozen konnyaku. High‐pressure‐freezing was ineffective in improving the texture of frozen‐then‐thawed konnyaku.
Thiamin Stability in Solids as Affected by the Glass Transition
Authors: Bell L.N. , White K.L. 
Published: July 2006

ABSTRACT:The stability of thiamin was evaluated in solid polyvinylpyrrolidone model systems as a function of water activity (aw) and the glass transition. In the glassy state, thiamin degradation rate constants correlated with the glass transition temperature (Tg), decreasing as Tg increased. Above aw 0.4, rate constants correlated better with aw rather than Tg. However, rate constants decreased in the rubbery state above aw 0.4, which could be attributed to glass transition‐induced structural collapse. Glass transition effects (mobility considerations, collapse) have a larger effect on thiamin stability than aw, which should be recognized during the development of fortified food products.
Inactivation Kinetics of Foodborne Spoilage and Pathogenic Bacteria by Ozone
Authors: Kim J.‐G. , Yousef A.E. 
Published: July 2006

ABSTRACT:Ozone was tested against Pseudomonas fluorescens, Escherichia coli O157:H7, Leuconostoc mesenteroides, and Listeria monocytogenes. When kinetic data from a batch reactor were fitted to a dose‐response model, a 2‐phased linear relationship was observed. A continuous ozone reactor was developed to ensure a uniform exposure of bacterial cells to ozone and a constant concentration of ozone during the treatment. Survivors plots in the continuous system were linear initially, followed by a concave downward pattern. Exposure of bacteria to ozone at 2.5 ppm for 40 s caused 5 to 6 log decrease in count. Resistance of tested bacteria to ozone followed this descending order: E. coli O157:H7, P. fluorescens, L. mesenteroides, and L. monocytogenes.