bluuebunny/crossref_metadata_2025 huggingface dataset:
Quality Changes in Stored Raw Grated Beetroots as Affected by Temperature and Packaging Film
Authors: LÓPEZOSORNIO M. M. , CHAVES A. R.
Published: August 2010

The effects of atmospheric composition and temperature on quality of grated beetroots were analyzed. Beetroots (Beta vulgaris L.) were washed, grated and packaged in trays wrapped with two films of different gas permeabilities. Trays were stored at 0°C or 4°C for a week and then transferred to 20°C. Changes in atmospheric composition, pigment content, pH, titratable acidity and production of exudate were monitored. Shelf‐life of grated beetroots was 7 d at 0°C and 3 to 4 d at 4°C. There was a notable decrease in pigment content during storage.
Sourdough Lactic Acid Bacteria Effects on Bread Firmness and Stalin
Authors: CORSETTI A. , GOBBETTI M. , BALESTRIERI F. , PAOLETTI F. , RUSSI L. , ROSSI J.
Published: August 2010

Lactobacillus sanfrancisco CB1 and Lactobacillus plantarum DC400 were the most proteolytic and amylolytic strains studied. Breads started with LAB and yeasts had higher volumes than the baker's yeast‐started bread. One bread with the highest initial firmness (Saccharomyces cerevisiae 141‐L. plantarum DC400 starter) had the lowest final firmness. Breads produced with LAB showed the lowest enthalpy throughout 144 h. After 24 h storage the associations of S. cerevisiae 141 and L. sanfrancisco CB1 or L. plantarum DC400 gave a very low percentage increase of enthalpy compared to that from yeast alone. The enthalpy increased markedly when other LAB, neither proteolytic nor amylolytic, were used.
Challenge Studies with Selected Pathogenic Bacteria on Freshly Peeled Hamlin Orange
Authors: PAO STEVEN , BROWN G. ELDON , SCHNEIDER KEITH R.
Published: August 2010

The survival and growth of Salmonella spp., Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus on peeled Hamlin orange were examined. Fruits were peeled by infusing the peel with water to assist hand removal. The peeled oranges had an average pH of 6.0–6.5 at the surface and 3.8 in the juice. After surface inoculation, peeled fruits were incubated for up to 14 days. Growth was observed with all tested pathogens only at the abusive storage temperature (24°C). Refrigeration (4 or 8°C) effectively inhibited the growth of all pathogens and caused population reduction of Salmonella spp. and S. aureus.
Textural and Physicochemical Properties of Low‐Fat, Precooked Ground Beef Patties Containing Carrageenan and Sodium Alginate
Authors: LIN KUO‐WEI , KEETON JIMMY T.
Published: August 2010

Textural and physicochemical characteristics of selected hydrocolloids incorporated into low‐fat, precooked, beef patties were investigated. Patties with an alginate/carrageenan combination had higher yields and percent moisture but lower shear force values than those of alginate or carrageenan treatments within the same fat level. Alginate appeared to improve texture slightly more than carrageenan, but carrageenan tended to release more free water after cooking and reheating. Patties with 10% fat were generally lower in shear value, cooking yield and percentage free water released as compared to their 5% fat counterparts with the same added ingredient. Low‐fat, precooked, ground beef patties containing alginate/carrageenan combinations were comparable to regular beef patties (20% fat control) regarding yields and textural properties.
Postharvest Gibberellin and Heat Treatment Effects on Polyamines, Abscisic Acid and Firmness in Lemons
Authors: VALERO D. , MARTÍNEZ‐ROMERO D. , SERRANO M. , RIQUELME F.
Published: August 2010

Lemons at two ripening stages were vacuum‐infiltrated with 100 ppm of gibberellin A3 (GA3) or heat‐treated at 45°C, and then stored at 15°C for 3 wk. Both treatments increased fruit firmness either in stage 1 or in stage 2. Also, the levels of free putrescine and spermidine in the skin were higher in treated lemons than in controls but spermine concentration did not show significant differences, in fruits of either stage. GA3 treatment was the most effective in retarding the color change during storage, especially in stage 1 fruits, which was related to the lowest levels of abscisic acid found.
Postmortem Changes of Cultivated Atlantic Salmon and Their Effects on Salt Uptake
Authors: WANG D. , TANG J. , CORREIA L.R. , GILL T.A.
Published: August 2010

Rigor mortis of cultivated Atlantic salmon (Salmo salar) began to set in 8h after death and was fully resolved 60–70h after death during storage at 0°C. Maximum muscle contraction was observed 24–30h after death. ATP content decreased from 7.25 to 0.14 to 0.09 μmol/g fish from pre‐rigor mortis to in‐rigor mortis to post‐rigor mortis state. The inosine and hypoxanthine contents increased from 0 to 1.20 to 4.06 μmol/ g fish and from 0.08 to 0.33 to 0.84 μmol/g fish during 60h storage, respectively, during 60h of storage at 0°C. Postmortem changes affected salt uptake. The equilibrium salt concentrations of pre‐rigor, in‐rigor and post‐rigor mortis salmon were 0.53, 0.66 and 0.75 g/g salt‐free solids, respectively, in a 20% (w/v) sodium chloride solution at 10°C.
Alginate Encapsulated Bifidobacteria Survival in Mayonnaise
Authors: KHALIL ALI H. , MANSOUR ESAM H.
Published: August 2010

Bifidobacterium bifidum and Bifidobacterium infantis were added to mayonnaise as either free cells or encapsulated. The survival of bifidobacteria and their effect on mayonnaise quality were evaluated. The viability of free cells disappeared after 2 wk; however, encapsulated B. bifidum survived well for 12 and B. infantis for 8 wk. Mayonnaise containing encapsulated bifidobacteria had lower total bacterial counts compared to other treatments. Yeast and mold started to appear after 12 wk of storage in mayonnaise containing encapsulated bifidobacteria and after 6 wk with other treatments (control, cells free of bifidobacteria). Mayonnaise containing encapsulated bifidobacteria had higher titratable acidity and lower TBA values than other treatments. Sensory properties of mayonnaise were improved by the addition of encapsulated bifidobacteria.
Antimicrobial Effects of Pressured Carbon Dioxide in a Continuous Flow System
Authors: SHIMODA M. , YAMAMOTO Y. , COCUNUBO‐CASTELLANOS J. , TONOIKE H. , KAWANO T. , ISHIKAWA H. , OSAJIMA Y.
Published: August 2010

The application of microbubbles of pressured CO2 greatly increased CO2 concentration in the solution treated. By treatment at 6 MPa, 35°C and average residence time 15 min, L. brevis was completely inactivated at the level of dissolved CO2,γ≧ 11 (γ, Kuenen's gas absorption coefficient). E. coli and S. cerevisiae required γ≧ 17, and T. versatilis required γ≧ 21 for complete inactivation. Z. rouxii could be sterilized at 20 MPa and 26. A comparison of the continuous and batch method showed that L. brevis was inactivated completely under pressured CO2 > 0.16 g/cm3 with the continuous method and >0.9 g/cm3 with the batch method.
Raw and Processed Oat Ingredients Lower Plasma Cholesterol in the Hamster
Authors: YOKOYAMA WALLACE H. , KNUCKLES BENNY E. , STAFFORD ALLAN , INGLETT GEORGE
Published: August 2010

The objective of this study was to determine if Oatrim, a product developed for use as a fat substitute, could also reduce plasma cholesterol due to its soluble dietary fiber content. Diets with soluble fiber contents of 0% (oat hydrolyzate) or 4.2–4.3%β‐glucan from oat or Oatrim were fed to hamsters for 21 days. All oat derived diets reduced serum cholesterol compared to a control diet containing cellulose (p≥0.05). The available carbohydrate produced by the Oatrim process correlated inversely (r20.95) with low density lipoproteincholesterol concentration.
Sulfurous Off‐Flavor Formation and Lipid Oxidation in Heat‐Sterilized Meat in Trays
Authors: LANGOURIEUX S. , ESCHER F.E.
Published: August 2010

The development of a strong sulfurous off‐flavor as compared to lipid oxidation in heat‐sterilized meat in trays was investigated. Hydrogen sulfide and ethane were used as indicators for sulfurous off‐flavor and lipid oxidation, respectively. Nitrogen flushing suppressed oxidation but greatly enhanced formation of hydrogen sulfide. Concentrations of hydrogen sulfide were lower in HTST‐processed meat and also decreased during storage of both nonflushed and nitrogen‐flushed samples. The addition of rosemary extract as primary antioxidant lessened both hydrogen sulfide and ethane formation for a limited storage period. Citric acid as the secondary antioxidant had little effect. Use of a primary antioxidant and application of HTST process conditions seemed to balance hydrogen sulfide and ethane formation.
Acceptance by American and Asian Consumers of Extruded Fish and Peanut Snack Products
Authors: SUKNARK K. , McWATTERS K.H. , PHILLIPS R.D.
Published: August 2010

Fish snack half‐products were produced using extrusion temperatures and screw speeds of 97°C and 285 rpm, 95°C and 350 rpm, and 95°C and 220 rpm. Peanutsnack half‐products were produced at 100°C and 250 rpm, 95°C and 325 rpm, and 95°C and 250 rpm. The half‐products were fried at 200°C for 1.5 min and evaluated for acceptability using a 9‐point hedonic scale. Temperature and screw speed influenced consumer acceptance. Aroma, flavor, and overall acceptance of fish snack products were rated significantly higher by Asian consumers(n = 30) than by American consumers (n = 30). There was no significant difference in ratings for all sensory attributes and overall acceptance of peanut snack products by Asian or American consumers.
Cook Yield, Texture and Gel Ultrastructure of Model Beef Batters as Affected by Low Levels of Calcium, Magnesium and Zinc Chloride
Authors: Nayak R. , Kenney P. B. , Slider S. , Head M. K. , Killefer J.
Published: August 2010

Effects of 0.05% CaCl2, MgCl2, or ZnCl2, with or without 0.4% sodium tripolyphosphate (STPP), were investigated in high fat (HF; 30% fat) or low fat (LF; 10% fat) model beef batters. Cook yield (CY), texture, and gel ultrastructure were evaluated. With STPP, CaCl2 increased CY, and in the absence of STPP, ZnCl2 decreased CY and cohesiveness (p<0.05). Low‐fat, ZnCl2‐treated batters without STPP had the lowest (p<0.05) hardness. Addition of STPP resulted in a homogeneous matrix in HF batters. In MgCl2‐treated HF batters, protein film surrounding fat globules had greater integrity than control, CaCl2 or ZnCl2 treatments. In ZnCl2‐treated HF batters (without STPP) a protein sheet was present without evidence of film encased droplets. Low‐fat batters with STPP had finer, more porous networks than those without STPP.
Myofibrillar Protein Solubility of Model Beef Batters as Affected by Low Levels of Calcium, Magnesium and Zinc Chloride
Authors: Nayak R. , Kenney P. B. , Slider S. , Head M. K. , Killefer J.
Published: August 2010

Preblended composites of semimembranosus and adductor muscles were stored 12h at 4°C with 2.0% NaCl, 0 or 0.05% CaCl2, MgCl2, or ZnCl2 and 0 or 0.4% sodium tripolyphosphate (STPP). Model systems were formulated to contain 30% fat (high fat; HF) or 10% fat (low fat; LF). Divalent salts lowered extract pH and ZnCl2 elicited the greatest reduction. At both fat levels, CaCl2 increased and ZnCl2 decreased protein solubility, compared to the control (p<0.05). Myosin was not detected in ZnCl2‐treated HF and LF batters without STPP and in the presence of STPP, MgCl2 and ZnCl2 increased myosin concentration at both fat levels (p<0.05). Zinc chloride increased actin concentration in HF batters; whereas, MgCl2 decreased soluble actin in LF batters (p<0.05). Magnesium chloride (0.05%) increased soluble proteins in LF batters containing 0.4% STPP by increasing myosin extractability.
Laboratory Reaction Cell to Model Maillard Color Development in a Starch‐Glucose‐Lysine System
Authors: Bates L. , Ames J. M. , MacDougall D. B. , Taylor P. C.
Published: August 2010

A starch‐glucose‐lysine Maillard system was heated in a reaction cell at different pHs (2.9 to 10.7), moisture (13 to 18%) and temperature (100 to 155°C). Tristimulus Z values were used to develop a quadratic response surface regression equation. Fitted values from the equation modeled very accurately the effect of pH (2.9 to 9.0), moisture and temperature. Color development followed Arrhenius kinetics over the range 120 to 155 °C. Activation energies for color development at all pH and moisture levels were between 41.1 and 110.6 kJ/mol. Activation energy generally decreased as moisture content increased and as pH increased from 8.5 to 10.7.
Color Characteristics of Irradiated Vacuum‐Packaged Pork, Beef, and Turkey
Authors: Nanke K. E. , Sebranek J. G. , Olson D. G.
Published: August 2010

Changes in color of irradiated meat were observed to be species‐dependent. Irradiated pork and turkey became redder due to irradiation but irradiated beef a* values decreased and yellowness increased with dose and storage time. The extent of color change was irradiation dose‐dependent and was not related to myoglobin concentration. Visual evaluation indicated pork and turkey increased in red ness whereas beef decreased in redness as dose levels increased. Reflectance spectra showed that irradiation induced an oxymyoglobin‐like pigment in pork and that both oxymyoglobin and metmyoglobin developed in beef as a result of irradiation.
Quality of Restructured Hams Manufactured with PSE Pork as Affected by Water Binders
Authors: Motzer E. A. , Carpenter J. A. , Reynolds A. E. , Lyon C. E.
Published: August 2010

Restructured hams were made from modified food starch (MFS), kappa‐carrageenan (k‐c), isolated soy protein (ISP), and processed with different levels of PSE pork [100% Normal, 50% PSE/50% Normal, 100% PSE]. Hams were ground, tumbled for 2h with a brine, stuffed, and water cooked. Bind strength values decreased and expressible moisture increased with addition of PSE pork to the ISP and k‐c treatments. Incorporation of MFS decreased bind strength and expressible moisture and increased yields in the 100P treatment. Results indicated MFS enhanced the water retention of PSE pork in a restructured product.
Emulsification of Commercial Dairy Proteins with Exhaustively Washed Muscle
Authors: Imm J. Y. , Regenstein J. M.
Published: August 2010

The addition of dairy proteins to exhaustively washed chicken breast muscle improved the emulsion stability in heated cream layers (emulsions) containing whey protein concentrate (WPC) or whey protein isolate (WPI). The initial weight of the heated cream layers made with WPC or WPI was heavier than those for sodium caseinate (CNate) or milk protein isolate (MPI). The addition of CNate or MPI resulted in decreased emulsion stability and increased inhibition of myosin heavy chain and actin participation in the emulsion formation compared to WPC or WPI.
Quality of Strawberries Automatically Packed in Different Plastic Films
Authors: García J. M. , Medina R. J. , Olías J. M.
Published: August 2010

The quality of strawberries (Fragaria ∞ ananassa Duch. cvs. Oso Grande and Camarosa) non wrapped or packed in cellulose, perforated polypropylene, nonperforated polypropylene (automatically), and polyvinylchloride (manually) during storage at 18°C was compared. Nonperforated polypropylene packages of fruit had the highest CO2 and the lowest O2 content, and the most desirable quality parameters. However, this type of package had undesirable appearance due to water condensation. Cellulosic films maintained a well balanced internal atmosphere, but were wrinkled. Perforated polypropylene and polyvinylchloride packages exhibited the best appearance, but fruits packed in perforated polypropylene o films rapidly deteriorated. Unwrapped fruits had the least desirable quality in both varieties.
True Thermal Conductivity Determination of Moist Porous Food Materials at Elevated Temperatures
Authors: Goedeken D. L. , Shah K. K. , Tong C. H.
Published: August 2010

Thermal conductivity (k) of bread samples, moisture content 5% to 44%, (w/w, wet basis) and porosity 0.18 to 0.90, was measured in a sealed stainless steel vessel using the probe method from 25 to 85°C. Significant differences were observed in measured thermal conductivity before and after air pressure was applied to the sample indicating the influence of vapor phase moisture migration on thermal conductivity. The difference increased as temperature and moisture content were increased. True thermal conductivity of bread was found to agree with predictions using a volume fraction model when moisture migration was completely suppressed at an applied air pressure of 18 atm.
Degradation Kinetics of Capsanthin in Paprika (Capsicum annuum L.) as Affected by Heating
Authors: Shin J.H. , Chung H.L. , Seo J.K. , Sim J.H. , Huh C.S. , Kim S.K. , Baek Y.J.
Published: August 2010

ABSTRACT: Diluted juice of paprika was heated at 80, 90 and 100°C with holding times of 0, 2, 4, 8 and 16 min. Capsanthin in each sample was determined by HPLC. The degradation kinetics of capsanthin was studied by two groups of reaction models including elementary reaction rate models and those of modified square root‐based pseudo (MRBP‐). The MRBP‐1st order reaction rate model was proven as an appropriate model in this study. The pseudo Q10 (PQ10) value was 1.045 and the predicted half‐life (capsanthin 2,850 mg/L) was 27.47, 21.23 and 15.23 min, respectively, at 80, 90 and 100°C.
Effect of SDS on Casein Micelles: SDS‐Induced Milk Gel Formation
Authors: Lefebvre‐Cases E. , La Fuente B. Tarodo De , Cuq J.L.
Published: August 2010

ABSTRACT: The addition of sodium dodecyl sulfate (SDS) during skim‐milk reconstitution contributed to a modification of hydrophobic interactions and, consequently, to change in the micellar structure. SDS‐induced modifications in casein micelles were investigated by biochemical measurements (soluble mineral and protein analyses, granulometric and electrokinetic potential measurements, and casein micelle solvation). SDS induced micellar κ‐casein dissociation and caused a decrease in steric, hydration, and electrostatic repulsive forces between casein micelles and as a result altered micellar stability. Consequently, SDS‐modified micelle aggregation occurred. Mineral analysis indicated that Ca, PO43‐ and Mg partitioning between aqueous phase and curd is similar, suggesting a possible bridging mechanism via minerals and SDS molecules.
Respiration Rate of Sweet Cherries: ‘Burlat’, ‘Sunburst’ and ‘Sweetheart’ Cultivars
Authors: Jaime P. , Salvador M.L. , Oria R.
Published: August 2010

ABSTRACT: Oxygen depletion and CO2 formation were measured using a closed system method at various temperatures. No CO2 inhibition effect was observed. Respiration rates were related to O2 concentration by a simple Michaelis‐Menten equation. Lineweaver‐Burk plots of respiratory rate versus O2 concentration were nonlinear over the whole O2 concentration range explored. However, this type of analysis allowed us to differentiate two O2 concentration intervals (above and below 10%) in which the double reciprocal plots are linear. Respiration rates decreased with decreasing temperature following the Arrhenius law. The Michaelis‐Menten equation constants Vm and Km for the 3 cultivars at 2, 5, and 20°C are tabulated.
Reactions of Plant Phenols with Myoglobin: Influence of Chemical Structure of the Phenolic Compounds
Authors: Kroll J. , Rawel H.M.
Published: August 2010

ABSTRACT: The reaction products of myoglobin and simple phenolic compounds, with different configurations of hydroxyl groups, and p‐quinone were characterized in terms of selected properties (electrophoretic, chromatographic and mass spectrometric) and by in vitro digestion. The o‐, and p‐hydroxyphenols, p‐quinone and gallic acid showed high reactivity leading to structural changes in myoglobin. In comparison, ferulic acid and m‐hydroxyphenol reacted to only a small extent, especially affecting tryptophan fluorescence of myoglobin. The enzymatic digestion (tryptic, a‐chymotryptic, peptic and pancreatic), on the basis of in vitro experiments with derivatized myoglobin, was adversely influenced.
Centrifugal Slump Test to Measure Yield Stress
Authors: Omura A.P. , Steffe J.F.
Published: August 2010

ABSTRACT: The performance of a centrifugal viscometer (a new concept) was tested for its ability to accurately predict the yield stresses of semisolid foodstuffs. This instrument is based on the traditional slump test concept, but utilizes centrifugal force rather than gravitational force to cause deformation. Using dimensional analysis, there was a general agreement between the theoretical approximation of the yield stress, and experimental data generated using the vane method.
Differential Glucose and Fructose Utilization During Cucumber Juice Fermentation
Authors: Lu Z. , Fleming H.P. , McFeeters R.F.
Published: August 2010

ABSTRACT: Glucose (32 mM) and fructose (36mM) of cucumber juice were degraded simultaneously by Lactobacillus plantarum, but at different rates and extents. Glucose depletion was slightly more rapid than fructose during the exponential growth phase, but slower thereafter and stopped before exhaustion. In contrast, fructose degradation continued until all naturally present fructose was exhausted. When cucumber juice was supplemented with fructose and/or glucose, the starter culture continued to ferment fructose, but not glucose, resulting in an increase in lactic acid production and a decrease in terminal pH. Fructose utilization was not affected by the presence of glucose, but the presence of fructose reduced glucose utilization.
Rheological Properties of Milkfat and Butter
Authors: Wright A.J. , Scanlon M.G. , Hartel R.W. , Marangoni A.G.
Published: August 2010

ABSTRACT: Butter and milkfat are examples of plastic materials for which texture is a critical factor in determining functionality and consumer acceptance. The methods by which butter rheology is characterized are discussed, including large deformation techniques such as cone penetrometry, compression, sectility and extrusion, and methods which involve testing at low levels of strain. Correlations between instrumental tests and sensory‐evaluated properties of the fats are explored. Rheological properties, including hardness, spreadability, setting, work softening, and thixotropy are described, and the models which have been proposed to characterize these behaviors are reviewed. Techniques which have been devised recently to quantitatively relate structural measurements to rheology are also examined. Modification of butter's rheological properties can be accomplished through alterations in composition or in the manufacturing process. These approaches are discussed and evaluated.
Effects of Heat Pretreatment on Lipid and Pigments of Freeze‐Dried Spinach
Authors: Cho E. , Lee J. , Park K. , Lee S.
Published: August 2010

ABSTRACT: Heat pretreatment resulted in decreases in drying yield and glycolipids (GL) and an increase in neutral lipids (NL). Triacylglycerol and free sterols in NL and sterylglycosides and monogalactosyldiglycerides in GL were more stable during heat pretreatment. Phosphatidylglycerol, phosphatidylethanolamine, and phosphatidic acid among phospholipid subclasses were more susceptible. There was no large difference in fatty‐acid composition of spinach lipids by heat pretreatment. However, a significant decrease in linolenic acid and increases in oleic and hexadecenoic acids were observed in NL. Contents of chlorophyll, lutein, and β‐carotene in spinach decreased by heat pretreatment, with the least decrease in lutein.
Rice Fry Texture as Affected by Gum Application and Mechanical Perforation
Authors: Kadan R.S. , Bryant R.J. , Boykin D.L.
Published: August 2010

ABSTRACT: This study was designed to evaluate the effects on rice fries with respect to lipid and moisture contents, as well as instrumental texture characteristics as a result of either coating with a water‐soluble gum solution or processing with a mechanical pinhole. The rice fries were formulated from 2 different rice flour mixtures. Statistical analyses showed that gum application significantly decreased fat absorption during frying and retained more moisture. The incorporation of a pinhole decreased moisture and increased fat contents. Increasing gum application lowered hardness and fracturability values. Gum application improved the overall appearance, as well as decreased popping and blistering of fries during final frying.
Evaluation of Zein Films as Modified Atmosphere Packaging for Fresh Broccoli
Authors: Rakotonirainy A.M. , Wang Q. , Padua G.W.
Published: August 2010

ABSTRACT: Modified atmosphere packaging (MAP) is increasingly used with minimally processed produce. Increased MAP usage coupled with negative environmental views associated with nondegradable synthetic packaging materials creates a need for biodegradable films. Zein films plasticized with oleic acid had been proposed for biodegradable packaging applications. Conversion treatments including lamination and coating films with tung oil were reported to improve water vapor and gas barrier properties of films. In this work, the ability of treated and untreated zein films to perform as MAP for fresh broccoli florets was investigated. Florets were packaged in glass jars sealed with zein films and stored under refrigeration for 6 d. Headspace oxygen and carbon dioxide concentrations were monitored during storage. Tested films allowed the development of modified atmospheres inside the packages. Broccoli florets packaged in the test films maintained their original firmness and color.
Effect of Hydrostatic Pressure on Aggregation and Viscoelastic Properties of Tilapia (Orechromis niloticus) Myosin
Authors: Hsu K‐C. , Ko W‐C.
Published: August 2010

ABSTRACT: Hydrostatic pressures from 500 to 2000 atmospheres (atm) were applied at 0°C to determine the aggregation and viscoelastic properties of tilapia (Orechromis niloticus) myosin. Native myosins were present as long, linear, and single filaments. After a 500‐atm treatment, these filaments unfolded and their volume decreased. Upon 1000‐atm and 1500‐atm treatments, myosins aggregated and formed inseparable network structures. Further, they transformed from viscous sol to elastic gels with a pressure of 500 to 1000 atm. At 2000 atm, the myosin formed irregular aggregates. This study reveals that at 500 atm, myosins unfolded; at 1000 atm, they aggregated, and beyond 1500 atm, they formed both a precipitate and gel.
Thermal Inactivation of Salmonella spp., Salmonella typhimurium DT104, and Escherichia coli 0157:H7 in Ground Beef
Authors: Smith S.E. , Maurer J.L. , Orta‐Ramirez A. , Ryser E.T. , Smith D.M.
Published: August 2010

ABSTRACT: In 19.1% fat ground beef, Escherichia coli 0157:H7 was less heat‐ resistant at ≥58°C than the Salmonella typhimurium DT104 and Salmonella senftenberg, but at 55°C the D value was similar to DT104 strains and higher than an eight‐strain Salmonella cocktail. Inactivation of E. coli 0157:H7 was more temperature‐dependent than the cocktail and DT104 strains. E. coli and DT104 strains were more heat‐resistant in beef containing 19% fat than 4.8% fat. The cocktail was more thermally stable in stationary as compared to log phase. Freezing of inoculated raw meat decreased heat resistance of the cocktail. The pathogenic strain, growth phase of the organism, state of the meat (fresh or frozen) and meat composition must be considered when designing protocols to verify thermal processes.
Mutagenicity and Acute Toxicity Evaluation of 2‐Dodecylcyclobutanone
Authors: Gadgil P. , Smith J.S.
Published: August 2010

ABSTRACT: Mutagenicity and acute toxicity of 2‐dodecylcyclobutanone (2‐DCB), a unique radiolytic product, were evaluated. Mutagenicity was evaluated by the Ames assay using 5 standard Salmonella tester strains with S9 enzyme activation and 5 concentrations of 2‐DCB. Sodium azide (NaN3), fenaminosulf, and2‐aminofluorene (2‐AF) served as positive controls. The Ames assay showed no difference between the 5 concentrations of 2‐DCB and the controls, including samples incubated with S9. The results indicate that 2‐DCB does not produce point or frameshift mutations in Salmonella and is not activated by S9. Acute toxicity of 2‐DCB was evaluated by the Microtox acute toxicity system and compared with cyclohexanone and 2‐nonenal (both GRAS additives). The effective concentrations that caused a 50% reduction in light emission by Vibrio fischeri cells (EC50) were; 21.72 6 14.57 ppm for 2‐DCB, 37.40 6 0.45 ppm for cyclohexanone, and 1.65 6 0.26 ppm for 2‐nonenal. The maximum number of cells affected by 2‐DCB was 65% 6 4%, while it reached 90% to 100% for the other 2 compounds. Our results suggest that even though the EC50 for 2‐DCB is lower than that for cyclohexanone, it was not toxic enough to decrease light emission of V. fischeri beyond 60% to 70%. These results indicate that the potential risk from 2‐DCB, if any, is very low.
Effects of Surface Characteristics and Xanthan Polymers on the Immobilization of Xanthomonas campestris to Fibrous Matrices
Authors: Hsu C.H. , Chu Y.F. , Argin‐Soysal S. , Hahm T.S. , Lo Y.M.
Published: August 2010

ABSTRACT: The production of xanthan gum, an industrially important microbial exopolysaccharide, was enhanced by using Xanthomonas campestris cells adsorbed to cotton fibers. However, the function of xanthan polymers during cell adsorption has not been elucidated. Polyethylenimine (PEI), a cationic polyelectrolyte, was employed to investigate respective effects of fiber surface properties and xanthan polymers during cell adsorption. Adsorption of X. campestris cells to fiber was independent of fiber roughness and hairiness, and the effect of electrostatic interactions between cells and fiber was insignificant. Fiber hydrophilicity was critical in initiating cell‐fiber contacts, whereas xanthan polymers enhanced retention of cells on fiber surface. The untreated cotton showed the highest immobilization efficiency and xanthan production.
Influence of Chemical Composition on the Isothermal Cocoa Butter Crystallization
Authors: Foubert I. , Vanrolleghem P.A. , Thas O. , Dewettinck K.
Published: August 2010

ABSTRACT: The influence of chemical composition on the isothermal cocoa butter crystallization was investigated quantitatively. Apart from the fatty acid and triacylglycerol profile, the amounts of some minor components (diacylglycerols, free fatty acids, phospholipids, soap, unsaponifiable matter, iron, and primary oxidation products) were determined. With the forward model selection technique, a multiple linear regression model was established, showing the influence of chemical characteristics on the different crystallization parameters of the new model to describe the fat crystallization kinetics as developed by Foubert and others (2002). The ratios of saturated to unsaturated fatty acids and monounsaturated to diunsaturated triacylglycerols have the most important effect on the amount of crystallization, the induction time of the 2nd step of the crystallization process, and the order of the reverse reaction. The more unsaturated fatty acids and the more diunsaturated triacylglycerols, the lower the amount of crystallization; the higher the induction time for the 2nd step of crystallization, the lower the order of the reverse reaction. The amount of diacylglycerols has the most important (negative) influence on the rate constant. Other minor components with a rather pronounced influence on different crystallization parameters are the free fatty acids, phospholipids, and traces of soap.
Jam Processing Effect on Phenolics and Antioxidant Capacity in Anthocyanin‐rich Fruits: Cherry, Plum, and Raspberry
Authors: Kim D.‐O. , Padilla‐Zakour O.I.
Published: August 2010

ABSTRACT:Four cultivars of sour cherries (Balaton, Karneol, Kroeker and Northstar), 2 cultivars of plums (BY 8158.50 and Methley), and 1 red raspberry cv. Prelude were analyzed for total phenolics, antioxidant capacity, and total anthocyanins before and after jam production to evaluate their changes after thermal processing. Fruits had total phenolics ranging from 245.7 to 398.5 mg gallic acid equivalent (GAE)/100 g. Antioxidant capacity of fruits ranged from 354.8 to 692.3 mg/100 g, expressed as vitamin C equivalent antioxidant capacity (VCEAC). Total anthocyanins of fruits ranged from 30.9 to 67.1 mg cyanidin 3‐glucoside equivalent (CGE)/100 g. In 100 g of jam, total phenolics varied from 132.9 to 218.9 mg GAE, while antioxidant capacity ranged from 205.6 to 373.5 mg/100 g VCEAC. Jams had total anthocyanins of 5.4 to 30.4 mg CGE/100 g. On the basis of fresh fruit (100 g), the processing and heating during jam making generally decreased the contents of total phenolics, VCEAC, and total anthocyanins. Major losses occurred in anthocyanin content where overall retention varied from 89% to 21%. HPLC analysis of individual anthocyanins from cherry cv. Balaton to its jam showed that processing caused 90% decrease in anthocyanins. The results indicated that more than 73% total phenolics and more than 65% antioxidant capacity were retained after processing fruits into jams. Optimization of food processing would help to conserve the bioactive phenolic compounds in fruits.
Whey Protein Film Composition Effects on Potassium Sorbate and Natamycin Diffusion
Authors: Franssen L.R. , Rumsey T.R. , Krochta J.M.
Published: August 2010

ABSTRACT: To assess the ability of whey protein films to act as antimicrobial carriers, the effect of film composition on preservative diffusion was investigated. Preservative diffusion coefficients were measured at 24°C in whey protein isolate (WPI) films with different WPI‐glycerol plasticizer ratios (1:1 to 15:1), beeswax (BW) content, 0% to 40% w/w dry solids, and preservative addition of 0.3% (w/w) natamycin or 1.6% (w/w dry solids) potassium sorbate. Diffusion coefficients for potassium sorbate and natamycin were in the ranges 1.09 × 10−11 to 13.0 × 10−11 m2/s and 6.16 × 10−14 to 37.8 × 10−14 m2/s, respectively, and significantly decreased as the WPI‐glycerol ratio increased. No significant difference in sorbate diffusion was seen with the addition of BW.
Physical Stability of Whey Protein‐stabilized Oil‐in‐water Emulsions at pH 3: Potential ω‐3 Fatty Acid Delivery Systems (Part A)
Authors: Djordjevic D. , Kim H.‐J. , McClements D.J. , Decker E.A.
Published: August 2010

ABSTRACT: The oxidative stability of polyunsaturated lipids can be improved by incorporating them in oil droplets surrounded by positively charged whey protein isolate (WPI) membranes. This study dealt with the factors that influence the physical properties of WPI‐stabilized oil‐in‐water emulsions at pH 3. Emulsions containing 5 to 50 wt% corn oil and 0.5 to 5.0 wt% WPI (protein‐to‐oil ratio of 1:10) were prepared at pH 3. The apparent viscosity of the emulsions increased appreciably at oil concentrations ≥ 35 wt%; however, the particle size was relatively independent of oil concentration. The influence of NaCl (0 to 250 mM) on the physical properties of 28 wt% emulsions was examined. Significant increases in mean particle size, apparent viscosity, and creaming instability occurred at ≥150 mM NaCl, which were attributed to flocculation induced by screening of the electrostatic repulsion between droplets. The influence of heat treatment (30°C to 90°C for 30 min) on 28 wt% emulsions was examined in the absence and presence of salt, respectively. At 0 mM NaCl, heating had little effect on the physical properties of the emulsions, presumably because the electrostatic repulsion between the droplets prevented droplet aggregation. At 150 mM NaCl, the mean particle diameter, apparent viscosity, and creaming instability of the emulsions increased considerably when they were heated above a critical temperature, which was 70°C when salt was added before heating and 90°C when salt was added after heating. These results have important implications for the design of WPI‐stabilized emulsions that could be used to incorporate functional lipids that are sensitive to oxidation, for example, ω‐3 fatty acids.
Correlation between Moisture and Water Activity of Honeys Harvested in Different Years
Authors: Cavia M.M. , Fernáez‐Muiño M.A. , Huidobro J.F. , Sancho M.T.
Published: August 2010

ABSTRACT: For the 1st time, a relationship has been investigated between moisture percentage (M) and water activity (aW) in honeys from 2 different harvesting years and 2 different climatic areas. Moisture was determined by measuring refractive index at 20°C, according to official methods. At the same time, aW of the same samples was assessed at exactly 20°C. Influence on the relationship of the crop's year, aging, and induced fine granulation was evaluated. The results show that, independent of all factors studied, an excellent and statistically significant linear correlation between both parameters [aW = 0.3114 + (0.0170 × M)] was found in all samples with a regression coefficient of 0.8809. The measurement of aW of honey is interesting but time‐consuming. This study concludes that this parameter can be easily calculated from the moisture percentage, thus avoiding the use of expensive and slow equipment for aW measurement.
Effects of Electron Beam Irradiation and Antimicrobials on the Volatiles, Color, and Texture of Ready‐to‐eat Turkey Breast Roll
Authors: Zhu M.J. , Mendonca A. , Min B. , Lee E.J. , Nam K.C. , Park K. , Du M. , Ismail H.A. , Ahn D.U.
Published: August 2010

ABSTRACT: Breast rolls with 6 antimicrobial additive treatments—no preservatives (control), 0.1% potassium benzoate (PB), 2% sodium lactate (SL), 0.1% potassium benzoate plus 2% sodium lactate (PB + SL), 2% sodium lactate plus 0.1% sodium diacetate (SL + SDA), and 0.1% potassum benzoate, 2% sodium lactate, and 0.1% sodium diacetate (PB + SL + SDA)—were prepared. Samples were irradiated at 0, 1.0, or 2.0 kGy, and then the quality characteristics of turkey rolls were analyzed. Adding 2% SL increased the hardness, springiness, cohesiveness, chewiness, and resilience of breast rolls. Addition of PB or SDA, and irradiation had no significant effect on texture. Adding 2% SL affected color values. The color a* and b* values of turkey rolls with 2% SL added were significantly lower than those of the control, and this difference was maintained after irradiation and during storage. No difference in color and texture was observed between turkey rolls added with SL and those added with SL + PB + SDA. Breast rolls containing antimicrobials had more lipid oxidation than control. Irradiation and storage slightly enhanced lipid oxidation, although the overall lipid oxidation was very low. Irradiation promoted the formation of dimethyl disulfide and dimethyl trisulfide. Adding PB in breast rolls greatly increased the formation of benzene during irradiation, whereas other antimicrobial additives had no significant effects on volatiles.
Optimization of Extraction Conditions for Pollock Skin Gelatin
Authors: Hou P. Z , Regenstein J.M.
Published: August 2010

ABSTRACT: Seven potential variables, pretreatment temperature, pretreatment time, concentration of OH−, concentration of H+, extraction temperature, extraction time, and skin/water ratio, were investigated by a 27‐3 fractional factorial design to identify critical control factors for pollock skin gelatin extraction, and 3 responses, yield, gel strength, and viscosity, were evaluated. The results suggest that 4 variables, pretreatment temperature, concentration of OH−, concentration of H+, and extraction temperature, have significant effects on gelatin extraction, and these key factors were then selected for the subsequent optimization using response surface methodology with a 4‐factor, 5‐level central composite rotatable design. It suggests that a concentration of OH− at 0.25 mol/L, a concentration of H+ at 0.09 mol/L, a pretreatment temperature at 2°C, and an extraction temperature at 50°C, will give the highest values for the 3 responses. The predicted responses for these extraction conditions are that the yield will be 18%, gel strength will be 460 g, and viscosity will be 6.2 c P.
Finite Element Modeling of Fluid Flow, Heat Transfer, and Melting of Biomaterials in a Single‐screw Extruder
Authors: Wang L.J. , Ganjyal G.M. , Jones D.D. , Weller C.L. , Hanna M.A.
Published: August 2010

ABSTRACT: A mathematical model was developed to simulate non‐isothermal plug flow of granular starch in feed zone, melting in transition zone, and non‐Newtonian melt flow in metering zone and die channel during single‐screw extrusion processing. The maximum deviations between the predicted and experimental pressure at the die entrance, product temperature at the die entrance, and minimum residence time were about 20%, 2.5%, and 8%, respectively, of the measured values when the barrel temperatures were 50°C in the feed zone and 120°C in the rest zones. The deviations were within 40%, 4%, and 15%, respectively, of the measured values when the barrel temperatures were 50°C in the feed zone and 140°C in the rest zones. Simulations were carried out to investigate the operating characteristics of an extruder, the melting degree, and profiles of pressure and bulk temperature during extrusion.
Efficacy of High Hydrostatic Pressure Treatment in Reducing Escherichia coli O157 and Listeria monocytogenes in Alfalfa Seeds
Authors: Ariefdjohan M.W. , Nelson P.E. , Singh R.K. , Bhunia A.K. , Balasubramaniam V.M. , Singh N.
Published: August 2010

ABSTRACT: The application of high hydrostatic pressure (HHP) technology as a seed decontamination technique was evaluated. Alfalfa seeds inoculated with Escherichia coli O157 and Listeria monocytogenes were air‐dried and subjected to independent HHP treatments of 275 to 575 MPa for 2 min or at 475 MPa for 2 to 8 min (40°C). There were 1.4‐log and 2.0‐log reductions in E. coli O157 populations at 575 MPa (2 min) and 475 MPa (8 min), respectively. However, these treatments caused only 0.8‐log and 1.1‐log reductions in L. monocytogenes counts. Treated seeds took longer to germinate, achieving germination rate of up to 34%, whereas 95% of the control germinated. Results suggest that L. monocytogenes is more resistant to the bactericidal effects of HHP than E. coli O157. Although HHP treatments achieved a greater reduction in E. coli O157, it was at the expense of seed germination. Overall, our results indicate that although HHP treatments reduced the populations of E. coli O157 and L. monocytogenes in alfalfa seeds, they did not completely eliminate these microorganisms.
Empirical Distribution Models for Escherichia coli 57:H7 in Ground Beef Produced by a Mid‐size Commercial Grinder
Authors: Flores R.A. , Tewart T. E. S
Published: August 2010

ABSTRACT: The purpose of this research was to develop empirical models that describe the amount and distribution of ground beef contaminated with Escherichia coli O157:H7 when a contaminated beef trim is introduced into a batch of uncontaminated beef before processing in a mid‐size commercial grinder (34 g/s). A beef trim was inoculated with a rifampacin‐resistant strain of E. coli O157:H7 and added to a batch of noncontaminated trims at the grinding step. To study the distribution of the E. coli O157:H7rif in the ground beef, 6 treatments with different inoculum levels (1 to 6 log10 colony‐forming units [CFU]) were tested. Removal or pick up of the residual contamination with E. coli O157:H7rif left in the grinder was evaluated. E. coli O157:H7rif was detected in 9% to 86% of the total ground beef for the 1 to 6 log10 CFU inoculum levels, respectively. E. coli O157:H7rif contamination was detected in the collar that fixes the grinder's die and blade to the hub. An exponential algorithm described the relationship between the quantities of ground beef containing E. coli O157:H7rif and the inoculum level (R2= 0.82). Distribution models based on a Chi‐squared algorithm were developed for each inoculum level describing the contamination level as a function of the batch fraction processed (R2= 0.81 to 0.99). The results of this study corroborate that when beef processors test for pathogenic contamination in a mid‐scale grinder, they should test the beef residues in the collar that fixes the grinder's die and blade to the hub.
From Probiotics to Prebiotics and a Healthy Digestive System
Authors: Gibson G.R.
Published: August 2010

ABSTRACT: Ingestion of probiotics can be recommended as a preventative approach to maintaining intestinal microflora balance and thereby enhance‘well‐being'. Undoubtedly, probiotic bacteria will vary in their efficacy. The literature indicates positive results in over 50 human trials with prevention/treatment of infections the most frequently reported. In theory, increased levels of probiotics may induce a ‘barrier’ influence against common pathogens. Mechanisms of effect are likely to include the excretion of acids (lactate, acetate), competition for nutrients and gut receptor sites, immuno‐modulation and the formation of specific antimicrobial agents. An alternative, or additional, approach is the prebiotic concept. This takes the view that probiotics are present indigenous to the gut and that a rational approach towards increasing their numbers would be to consume food ingredients (carbohydrates) that have a selective metabolism in the lower gut. A prebiotic is‘a nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon that can improve the host health.' In particular, the ingestion of fructo‐oligosac‐charides, galacto‐oligosaccharides, and lactulose has shown to stimulate bifidobacteria in the lower gut.
Metric Evaluation of Technologies for Long Duration Space Missions: Application to Bread Makers
Authors: French S.J. , Perchonok M.H.
Published: August 2010

ABSTRACT: Technologies are being evaluated by National Aeronautics and Space Administration (NASA)'s Advanced Food Technology element. A transportation cost measure known as equivalent system mass (ESM) is being implemented at NASA as a preliminary assessment strategy for technologies. This study concentrated on calculating ESM values for 3 commercial bread‐maker technologies and aprototype bread‐maker technology currently unavailable in the marketplace. Information regarding weight, volume, power consumption, cooling, and crewtime were collected. One commercial technology produced a lower ESM value and performed better in most evaluative categories. However, non‐ESM factors may contribute greater roles in technology selection. In this, the current ESM equation may not be capable of capturing all relevant aspects of a food technology. bread
Antioxidative Activity and Gelling Rheological Properties of Dried Egg White Glycated with a Rare Keto‐hexose through the Maillard Reaction
Authors: Sun Y. , Hayakawa S. , Izumori K.
Published: August 2010

ABSTRACT: The functional properties of egg white (EW) glycated with a rare D‐psicose and 2 alimentary sugars (D‐fructose and D‐glucose) were investigated. Glycation led not only to the formation of cross‐links but also to the formation of antioxidative substances to EW, the extent of which depended on the sugar used, modification, and incubation time. The temporal development of browning and fluorescence of psicose‐EW was relatively faster than those of fructose‐EW and glucose‐EW. The psicose‐EW showed the greater 2,3‐bis (2‐methoxy‐4‐nitro‐5‐sulfophenyl)‐2H‐tetrazolium‐5carboxanilide (XTT) reducibility, 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid radical scavenging activity, and gelling rheological properties. These results indicated that psicose‐EW as a food ingredient might have the ability to improve gelling behavior and decrease oxidation reactions during food processing and storage.
Effect of Moisture Content of Carrot Slices on the Fat Content, Carotenoid Content, and Sensory Characteristics of Deep‐fried Carrot Chips
Authors: Sulaeman A. , Giraud D.W. , Keeler L. , Taylor S.L. , Driskell J.A.
Published: August 2010

ABSTRACT: Our objective was to develop a reduced‐fat deep‐fried carrot chip. Moisture contents of the carrot slices were altered, and fat uptake and quality parameters were measured. Decreasing moisture content of carrot slices significantly decreased (P < 0.05) the yield, hue∘ value, and fat uptake, and increased the redness value, which correlated with increased carotenoid content, but did not influence chip lightness, yellowness, water activity, and moisture content. Removing 50% of the initial moisture content of the carrot slices decreased the chips' fat content from 57% to 38.5%. Adjusting the moisture level of the carrot slices appears to influence fat uptake and carotene content of deep‐fried carrot chips.