bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Water Separation from Cooked Starch and Flour Pastes after Refrigeration and Freeze‐thaw
Authors: ZHENG G. H. , SOSULSKI F.W.
Published: July 2006

A procedure for determination of net syneresis in starch and flour materials was developed based on free water in freshly cooked pastes, syneresis water expelled during cold storage and absorbed water in the contracted gel. Free water values decreased from 50% to <5%, as starch concentrations increased from 4 to 10%, indicating the need for correction of expelled+absorbed water values from free water for calculating net syneresis. Normal cereal, root and dicotyledonous seed starches exhibited a broad range of expelled water values during refrigeration, but gave high absorbed water values during freeze‐thaw cycles. Waxy starches had low net syneresis during refrigeration and, except waxy corn, during freeze‐thaw. For comprehensive evaluation, two refrigeration and two freeze‐thaw cycles are recommended.
Physiological Characterization of Common Fungi Associated with Cheese.
Authors: HAASUM IBEN , NIELSEN PER VÆGGEMOSE
Published: July 2006

A multivariate statistical method (PLS) was used for a physiological characterization of fungi associated with the cheese environment. The combined effects of pH, salt content, oxygen and carbon dioxide levels on growth and sporulation were studied. Significant factors affecting growth were salt content, level of carbon dioxide and temperature. Interactions between those factors were illustrated and showed that some fungi were especially sensitive to carbon dioxide levels and salt content, at low temperature. Sensitivity to the factors often was more pronounced in the early growth phase. Results may aid in eliminating unwanted fungal growth during cheese production.
Cohesiveness of Mass Evaluation by Time‐intensity and Single Value Measurements
Authors: DESOBRY‐BANON S. , VICKERS Z.
Published: July 2006

The cohesiveness of mass of three commercial food products and three model systems was determined by Time‐Intensity (TI) and single‐value measurements. Two kinds of TI profiles were identified. The first corresponded to products that initially have a cohesive mass which is broken down during chewing. The second profile was characterized by the development and subsequent breakdown of cohesiveness of mass with oral manipulation. Maximum Intensity (Imax), total duration (DUR), area under the curve (AUC) and time to maximum intensity (Tmax) most significantly differentiated the products. Imax was the TI parameter most closely related to single‐value measures of cohesiveness of mass.
Stability and Photochemistry of Vitamin D2 in Model System
Authors: LI TSUNG‐LIN , MIN DAVID B.
Published: July 2006

Oxidation of vitamin D2 in a model system of 12% water and 88% acetone in the presence of 15 ppm riboflavin under light and dark was studied by measuring the depleted headspace oxygen. Riboflavin accelerated the oxidation of vitamin D2 by singlet oxygen under light, but did not affect the vitamin D2 oxidation under dark. The effect of 0 and 15 ppm riboflavin on the stability of vitamin D2 during storage at 25 and 60°C was studied by measuring the contents of vitamin D2 during 48h. Results indicated that photosensitized singlet oxygen oxidation of vitamin D2 under light was temperature‐independent, and triplet oxygen oxidation of vitamin D2 both under light and in the dark was temperature‐dependent.
Separation of Immunoglobulin G from Cheddar Cheese Whey by Avidin‐Biotinylated IgY Chromatography
Authors: KIM H. , LI‐CHAN E. C. Y.
Published: July 2006

High‐purity immunoglobulins (Ig), which may be useful for immunologic supplementation of food products, were isolated from Cheddar cheese whey in a one‐step process using avidin‐biotinylated yolk immunoglobulin (IgY) column chromatography. Yolk antibodies specific to bovine IgG (IgYIgG) were biotinylated with biotinyl amido‐hexanoic acid‐N‐hydroxy‐sulfo‐succinimide ester without any notable effect on antigen‐binding activity, and coupled to immobilized avidin columns. The resulting avidin‐biotinylated IgYIgGcolumns, with binding capacity of 50–55% (w/w percent ratio of IgG to immobilized IgYIgG), were used for specific binding of IgG from cheese whey. Elution with a commercially available eluent (Actisep) or 0.1 M glycine‐HCl buffer at pH 2.8 yielded IgG with purity of 99% by radial immunodiffusion.
Bioconversion of Citrus Aroma Compounds by Pichia pastoris
Authors: GOODRICH R.M. , BRADDOCK R.J. , PARISH M.E. , SIMS C.A.
Published: July 2006

After induction of alcohol oxidase, active Pichia pastoris cells were grown in model alcohol solutions and orange aroma, a by‐product rich in potential alcohol substrates for bio‐oxidation to aldehydes. Acetaldehyde production efficiency was 60% at 0.1% ethanol, decreasing with increasing ethanol. Acetaldehyde, propanal, and octanal were generated using the Pichia system with orange aroma as substrate. Acetaldehyde concentration doubled during a 24h reaction time at 30°C. In contrast to use of isolated alcohol oxidase, the whole cell system had the advantage of cofactor regeneration and associated enzyme systems, including formaldehyde dehydrogenase. Sensory differences were found in the full strength biomodified aroma. Presented in a paired comparison aroma test, to a trained panel it rated higher for the attributes orange character, freshness, and fruitiness than the unmodified control.
Mechanical and Structural Changes in Apple (Var. Granny Smith) Due to Vacuum Impregnation with Cryoprotectants
Authors: MARTÍNEZ‐MONZÓ J. , MARTÍNEZ‐NAVARRETE N. , CHIRALT A. , FITO P.
Published: July 2006

Freezing ensures the longterm preservation of fruits, but usually destroys cell compartmentation of fruit tissues, thereby increasing the probability of undesirable reactions. The use of cryoprotectants/cryostabilizers may reduce ice crystal damage by modifying the glass transition of frozen fruit or reducing freezable water content. The use of vacuum impregnation to introduce cryopreservatives into the fruits was tested. Apple samples were vacuum impregnated with concentrated grape musts and pectin solutions, by applying vacuum (50 mbars) for 5 min and afterwards restoring atmospheric pressure while fruit remained immersed. Most compositional, mechanical and structural properties improved as a result of vacuum impregnation.
Improved Ultrafiltration for Color Reduction and Stabilization of Apple Juice
Authors: GÖKMEN VURAL , BORNEMAN ZANDRIE , NIJHUIS HERRY H.
Published: July 2006

Polyphenols that are responsible for haze‐formation and browning during storage of clear apple juice and concentrates could be selectively removed by an ultrafiltration process using membranes of polyether sulfone and polyvinylpyrrolidone. Results were compared with those from commercial UF membranes made out of regenerated cellulose acetate. The effects of laccase treatment on removal of polyphenols and color in apple juice were also investigated. Custom membranes were effective to reduce the amount of polyphenols. A remarkable desired color removal of apple juice could also be achieved using these membranes. Resulting products were stable in color and clarity at 50°C up to 6 wk. Laccase treatment increased the percentage removal of polyphenols from apple juices. However, laccase treated samples were more susceptible to coloration and haze‐formation during storage.
Pulse NMR Study of Glass Transition in Maltodextrin
Authors: Ruan R. , Long Z. , Chen P. , Huang V. , Almaer S. , Taub I.
Published: July 2006

A pulse nuclear magnetic resonance (NMR) technique was used to study the glass transition in maltodextrins. The spin‐lattice relaxation time (T1 and spin‐spin relaxation time (T2) of different molecular weight maltodextrins at different moisture contents and temperatures were measured using the pulse NMR tech nique. T1, and T2 were plotted against temperatures. From the resultant curves, the state transitions were observed and the corresponding state transition temperatures were determined. The state transition temperatures were very close to the glass transition temperatures (Tgs) determined with differential scanning calorimetry, suggesting a strong relationship between glass transition and proton relaxation behavior. Results indicate pulse NMR‐based instrumentation could be very effective for the study of glass transition in food polymers.
Proteolysis of Fynbo Cheese Salted with NaCl/KCl and Ripened at Two Temperatures
Authors: Laborda M. A. , Rubiolo A. C.
Published: July 2006

Cheeses salted in solutions of 100g NaCl/L and 100g KCl/L and ripened for 90 days at 12°C and 16°C were compared with cheeses salted in brine of 190g NaCl/L and ripened at the same temperatures. Peptides of the water‐soluble nitrogen (WSN) fraction were quantified by the Kjeldahl method and analyzed by reverse‐phase HPLC. There were no differences (P>0.05) attributable to salt treatments; and the cheeses stored at 16°C showed higher levels of WSN/Total Nitrogen (TN) than cheeses ripened at 12°C. HPLC profiles of WSN extracts showed differences in the hydrophilic zone for cheeses ripened at different temperatures, but profiles were similar for cheeses salted with NaCl and with NaCl/KCl.
Respiration Rate of a Dry Coleslaw Mix Affected by Storage Temperature and Respiratory Gas Concentrations
Authors: McLaughlin C. P. , O'Beirne D.
Published: July 2006

The respiration rate of dry coleslaw mix at different concentrations of O2 and CO2 was determined in an open flow‐through respirometer at 5°C. Product O2 consumption rate fitted an enzyme kinetics model. Vm and Km values of 22.72 mlkg‐1h‐1 and 1.083 %O2, respectively were calculated. CO2 had an inhibitory effect on respiration rate. The effect of CO2 on respiration gave a good fit with an uncompetitive inhibition enzyme kinetics model (E = 5.11%). Product respiration rate increased with temperature by an Arrhenius type relationship. Activation energies for O2 consumption and CO2 evolution were 74.8 kJ/kg and 84.2 kJ/kg respectively. These results provide information essential for the design and optimization of modified atmosphere packs for this product.
Cooking Temperature, Bird Type, and Muscle Origin Effects on Sensory Properties of Broiled Emu Steaks
Authors: Fitzgerald D. R. , Thompson L. D. , Miller M. F. , Hoover L. C.
Published: July 2006

Trained sensory panel scores and Warner‐Bratzler shear values (WBS) of emu meat cooked to three end‐point temperatures (60, 66, and 75°C), obtained from two bird types (breeder quality, BQ; and nonbreeder quality, NBQ), and from five carcass locations were determined and compared in three studies. NBQ birds had obvious conformational defects. Full rumps and inside drums broiled to 60°C were more tender and juicy than those broiled to 66 or 75°C (P<0.05). Cooking temperature did not affect meat‐flavor intensity (p>0.05). BQ vs NBQ sources had no effect on tenderness or juiciness (p>0.05). Differences in tenderness, juiciness, meat‐flavor intensity and WBS were found among the five meat cuts (P<0.05).
Acceptability of Extruded Corn Snacks as Affected by Inclusion of Soy Protein
Authors: Faller J.Y. , Klein B.P. , Faller J.F.
Published: July 2006

Our objectives were to develop acceptable extruded snack products containing soy protein, and to evaluate the influence of soy protein type, soy level, and moisture content. Addition of soy protein increased die temperature and pressure while decreasing motor torque. Results of two consumer tests for 12 prototype products and the most acceptable three samples indicated positive responses. Acceptance correlated highly with consumer attitudes toward soy foods and prior information about health effects of soy protein. Differences between protein types suggested that formulation optimization could develop highly acceptable soy/corn extruded snacks.
Canthaxanthin as an Antioxidant in a Liposome Model System and in Minced Patties from Rainbow Trout
Authors: Clark T.H. , Faustman C. , Chan W.K.M. , Furr H.C. , Riesen J.W.
Published: July 2006

Canthaxanthin (CX) delayed formation of thiobarbituric acid reactive substances (TBARS) in a concentration‐dependent manner in a ferrous chloride (FeCl2)‐initiated liposome system at 37 °C (p < 0.05). CX delayed TBARS formation in minced flesh from rainbow trout (Oncorhynchus mykiss) at 6 d of 4 °C storage in trial 1, and at 0, 2, 4 and 6 d in trial 2 when compared with controls at 4 °C (p < 0.05). Day 0 TBARS values in trial 2 were equivalent to d 6 of trial 1. CX concentration and a* value decreased in minced trout flesh during 6 days of 4 °C storage (p < 0.05). Overall, CX demonstrated antioxidant activity in vitro and in the minced tissue of CX‐supplemented rainbow trout.
Rapid Food Particle Temperature Mapping During Ohmic Heating Using FLASH MRI
Authors: Ruan R. , Chen P. , Chang K. , Kim H.‐J. , Taub I.A.
Published: July 2006

A fast low angle shoot (FLASH) pulse sequence in combination with a multi‐inversion procedure was used to rapidly acquire spin‐lattice relaxation data for food particles undergoing ohmic heating. The relaxation data acquired by magnetic resonance imaging (MRI) were analyzed using a two‐component exponential model to extract both short and long spin‐lattice relaxation time, T1. The longer T1 showed a better linear relationship with temperature than the shorter T1 and, therefore, was used to produce more reliable temperature maps. The MRI temperature maps constructed for ohmically heated food particulates showed an entirely different heating pattern than would be found for similar but conventionally heated particulates and indicated that the temperature inside the particulate could be higher than near the surface of the particulate.
Temperature Dependency of Compression Properties of Fish‐meat Gel as Affected by Added Starch
Authors: Kong C.S. , Ogawa H. , Iso N.
Published: July 2006

The influence of starch addition on the elastic properties of fish‐meat gel was studied by measuring compression and stress relaxation properties and dynamic viscoelasticity. Samples with pregelatinized starch, with and without raw starch, and processed starch were used. Fish‐meat gels with starch showed a higher modulus value at 80°C than at 90°C. The gelatinization of starch appeared to be prevented by surimi protein in the fish‐meat gel, and so the sample that gelled at 90°C had a lower “packing effect” than the sample that gelled at 80°C. The optimum heating temperature indicated a higher “packing effect” on the surimi protein.
Starch Conversion During Extrusion as Affected by Added Gelatin
Authors: Wulansari R. , Mitchell J.R. , Blanshard J.M.V.
Published: July 2006

Waxy maize starch was modified by twin‐screw extrusion cooking in the presence and absence of gelatin. X‐ray diffraction, microscopy, rheology, and differential scanning calorimetry studies showed that, at constant specific mechanical energy and extruder heater temperatures, the degree of starch conversion decreased with increasing levels of gelatin. It was hypothesized that during extrusion cooking, the gelatin acts as a lubricant, protecting the starch from being converted since more mechanical energy would be dissipated in the gelatin phase than the starch phase.
Chlorine Dioxide Treatment of Seafoods to Reduce Bacterial Loads
Authors: Kim J. M. , Huang T.‐S. , Marshall M. R. , Wei C.‐I.
Published: July 2006

Various seafoods were treated with fresh chlorine dioxide (ClO2) solutions (20, 40, 100, and 200 ppm total available ClO2) in 3.5% brine for 5 min, and bacterial loads and sensory quality were evaluated after 0, 3, and 7 d storage on ice. The ClO2 treated groups at each time period had lower bacterial counts than nontreated and brine‐treated groups. The differences in bacterial counts were significant, especially for groups treated with 100 and 200 ppm ClO2. Treated ClO2 solutions contained very low or no bacterial loads. Treated red grouper and salmon with 100 or 200 ppm ClO2 developed skin discoloration (lighter color) and a chocolate color in the gills.
Reduction of Warmed‐Over Flavor Volatiles from Freeze‐Dried Lean by Supercritical CO2 Extraction
Authors: Thongwong A. , Fernando L.N. , Grün I.U. , Clarke A.D.
Published: July 2006

Supercritical carbon dioxide (SC‐CO2) was used to extract warmed‐over flavor (WOF) volatiles from cooked, freeze‐dried beef at 40°C and pressures of 10.3 MPa or 30 MPa after 2 days storage. WOF markers, hexanal, heptanal, octanal, nonanal, and 2,3‐octanedione, were identified in the volatiles profile of precooked beef by dynamic headspace extraction and gas chromatography‐mass spectrometry before and after CO2 extraction. TBARS and levels of WOF markers increased over 2 days storage. There was a reduction in WOF markers at both extraction pressures. The higher pressure led to greater reduction of WOF markers (e.g., hexanal: 73.5%) than the lower pressure (e.g., hexanal: 60.3%), notably for heptanal and nonanal. SC‐CO2 may be applicable for reducing WOF volatiles from precooked meats.
Interactive Effects of Pressure, Temperature and Time on the Molecular Structure of β‐Lactoglobulin
Authors: Tedford L‐A. , Kelly S.M. , Price N.C. , Schaschke C.J.
Published: July 2006

We studied the combined effects of several variables, using temperatures up to 79°C and pressures up to 105 MPa, on β‐lactoglobulin at pH 7.0 and pH 5.6 by examination of circular dichroism spectra and application of experimental design methodology. The higher pressures were not sufficient to impart the energy necessary to disrupt the protein structure. When used in combination with temperature and holding time, the applied energy was sufficient to disrupt the tertiary structure of the protein. Processing conditions applied at specific pH therefore could act in combination to cause structural changes.
Porosity of Microcapsules with Wall Systems Consisting of Whey Proteins and Lactose Measured by Gas Displacement Pycnometry
Authors: Moreau D. L. , Rosenberg M.
Published: July 2006

Porosity characteristics of anhydrous milkfat‐containing, spray‐dried microcapsules with wall systems consisting of mixtures of whey proteins and lactose were investigated by gas displacement technique, using helium and nitrogen as displacing gases. Microcapsules exhibited molecular‐sieve type porosity. Results indicated that 8–12% of microcapsule volume was inaccessible to helium. Permeation of nitrogen to wall matrices was inversely proportional to lactose content. Pore volume that was inaccessible to nitrogen penetration ranged from 0.128 to 0.263 cm3/g for core‐free and from 0.121 to 0.214 cm3/g for core‐containing capsules. It was affected by wall composition and core load. Results suggested that adjusting microcapsule composition could modulate gas penetration into microcapsules.
Gel Forming Additive Effects on Properties of Thermally Induced Minced Fish Gel
Authors: Gao J. C. , Pigott G. M. , Reine B.
Published: July 2006

Water‐binding capacity (WBC) and hardness of minced chum salmon flesh decreased after 3 mo frozen storage. Additives with phosphate, carrageenan, soy protein isolate increased the WBC of fresh and frozen minced chum salmon flesh, and the texture profile analysis (TPA) hardness of the thermally‐induced myofibrillar protein gels of salmon flesh. TPA hardness was a useful index for characterizing sensory hardness of the cooked minced products. The observation of gel structure by scanning electron microscope showed additives modified the microstructure of fish myofibrillar protein gel and the ability of the gel network to bind water, thus resulting in minced flesh with different WBC and gelling ability.
Highly Concentrated Branched Oligosaccharides as Cryoprotectant for Surimi
Authors: Auh J. H. , Lee H. G. , Kim J. W. , Kim J. C. , Yoon H. S. , Park K. H.
Published: July 2006

Freeze‐thawing studies at different concentrations, using an actomyosin solution (extracted from Alaska pollock), revealed that an 8% (w/v) solution of oligosaccharides mixture (HBOS) was most effective in cryoprotection. During frozen storage (‐18°C), HBOS showed cryoprotective effects similar to sucrose and a sucrose+sorbitol mixture (1:1). Surimi gel prepared with HBOS showed higher hardness and more dense microstructure than others, although water holding capacity was slightly lower than the gel with sucrose+sorbitol. HBOS containing gel showed lower whiteness than sucrose but no difference with sucrose+sorbitol. HBOS appeared to have good potential as a non‐sweet cryoprotectant of fish protein.
Post‐Mortem Softening of Fish Muscle During Chilled Storage as Affected by Bleeding
Authors: Ando M. , Nishiyabu A. , Tsukamasa Y. , Makinodan Y.
Published: July 2006

Bleeding caused the delay of muscle softening in yellowtail, horse mackerel, and striped jack, which are pelagic fish. Conversely, bleeding had no influence on the muscle firmness of red sea bream, flatfish, and rudder‐fish, which are demersal fish. Transmission electron microscopy showed delay of degradation of pericellular collagen fibrils in bled yellowtail and horse mackerel. Striped jack showed slower weakening of the pericellular connective tissue in a compression test. However, the demersal fish had no structural difference due to bleeding. These results indicate that removal of blood could delay collagen fibril degradation and muscle softening of pelagic fish.
Extracellular Ice Nucleators from Pantoea Ananas: Effects on Freezing of Model Foods
Authors: Zasypkin D.V. , Lee Tung‐Ching
Published: July 2006

Parameters of freezing of sucrose solutions and emulsions were evaluated using differential scanning calorimetry (DSC) at cooling rates of 1 to 20°C/min. The differential and cumulative nucleation spectra of extracellular ice nucleators (ECINs) were established using a w/o emulsion technique. Freezing curves were obtained in a cabinet at −7 and −12°C. The ECINs increased the ice nucleation temperature and reduced the time of the supercooling stage. Although the time of phase transition increased in the presence of ECINs, the total time of freezing decreased. The ECINs caused lower onset temperatures of freezing as compared to the original cells.
Electrolyzed Water as a Disinfectant for Fresh‐cut Vegetables
Authors: Izumi H.
Published: July 2006

The effect of electrolyzed water on total microbial count was evaluated on several fresh‐cut vegetables. When fresh‐cut carrots, bell peppers, spinach, Japanese radish, and potatoes were treated with electrolyzed water (pH 6.8, 20 ppm available chlorine) by dipping, rinsing, or dipping/blowing, microbes on all cuts were reduced by 0.6 to 2.6 logs CFU/g. Rinsing or dipping/blowing were more effective than dipping. Electrolyzed water containing 50 ppm available chlorine had a stronger bactericidal effect than that containing 15 or 30 ppm chlorine for fresh‐cut carrots, spinach, or cucumber. Electrolyzed water did not affect tissue pH, surface color, or general appearance of fresh‐cut vegetables.
Moisture Distribution and Microbial Quality of Part Baked Breads as Related to Storage and Rebaking Conditions
Authors: Leuschner R. G. K. , O'Callaghan M. J. A. , Arendt E. K.
Published: July 2006

Storage conditions of part‐baked brown soda bread were studied as related to changes of crust and crumb moisture during rebaking at in‐oven temperatures of 180 and 200°C for 10–40 min. Baking loss during rebaking originated solely from the crust area, whereas the moisture content of the crumb remained constant. Packaging in an atmosphere of 40% CO2 and 60% N2 and storage at 4°C inhibited microbial contamination for 13 wk. The relationship of moisture content and water activity of part‐baked breads followed the characteristic of a sorption isotherm and was mathematically described by either a quadratic or exponential function.
New Line Intersection Procedure for the Equivalent Point Method of Thermal Evaluation
Authors: Kyereme M. , Swartzel K.R. , Farkas B.E.
Published: July 2006

A new Line Intersection (LI) procedure for determining sterilization value (Fo) and quality or nutrient retention (cook value: Co) was developed using the original Equivalent Point Method (O‐EPM). Analysis of 30 conventional and 5 simulated thermal curves showed excellent agreement between Fo values determined by the new LI method and the traditional General Method (GM). The new LI method performed better than the O‐EPM in yielding more accurate estimates of Fo and Co values as shown by the relatively low errors. The difference between Fo (GM) and Fo (LI) expressed as percent of Fo (GM) for conventional curves ranged from ‐0.01% to 0.78% while that between Fo (GM) and Fo (O‐EPM) ranged from ‐0.18% to 38.78%. Similar results were obtained for Co values.
Breadmaking Properties of Triticale Flour with Wheat Flour and Relationship to Amylase Activity
Authors: Seguchi M. , Ishihara C. , Yoshino Y. , Nakatsuka K. , Yoshihira T.
Published: July 2006

Wheat flour was blended with triticale flour and baking tests were performed. When 18.3% of triticale flour was blended with wheat flour, the greatest bread height (mm) and specific volume (cm3/g) were obtained. Triticale flour was fractionated into water solubles, gluten, prime starch, and tailings by acetic acid (pH 3.5) fractionation. Baking results indicated that only the water solubles fraction produced the same baking performance as the original triticale flour. Several types of triticale flour were blended with wheat flours, and the breadmaking tests and measurement of amylase activities were compared. Baking results appeared to be related to a‐amylase activity of triticale flour.
Starch Gelation Process Observed by FT‐IR/ATR Spectrometry with Multivariate Data Analysis
Authors: Iizuka K. , Aishima T.
Published: July 2006

For directly observing changes related to the gelation process of starch, IR spectra of starch in water while heating were obtained using FT‐IR/ATR spectrometry. Relationships between gelation and spectral changes were examined using factor analysis, evolving factor analysis (EFA) and three‐way principal component analysis (PCA). Absorption at 3300 and 1610 cm‐1 decreased with temperature but absorption at 1000 cm‐1 increased. The factor score plot patterns of amylose, amylopectin and rice starches were similar but those of potato and corn starches were unique. EFA indicated variances relating to changes caused in starch and water as different factors. Loadings of the starch component 2 in three‐way PCA correlated with starch granule sizes.
Muscle Firmness and Structure of Raw and Cooked Arrow Squid Mantle as Affected by Freshness
Authors: Ando M. , Ando M. , Tsukamasa Y. , Makinodan Y. , Miyoshi M.
Published: July 2006

Changes in firmness and structure of arrow squid (Loligo bleekert) mantle muscle during refrigeration (5°C) were studied. Shear force of raw mantle decreased sharply between 3 and 9 h refrigeration after killing. Light microscopic observations showed many pores between muscle cells in the softened raw samples. Transmission electron microscopic observations suggested that the spaces appeared as a result of detachment of muscle cells from connective tissues. After cooking the stored raw muscle, the shear force and muscle structure were almost the same for samples with different storage times. Freshness had an influence on raw squid muscle firmness and structure but not on cooked muscle.
Compounds Contributing to the “Beany” Odor of Aqueous Solutions of Soy Protein Isolates
Authors: Boatright W. L. , Lei Q.
Published: July 2006

Using gas chromatography/olfactometry (GCO), major odors from the headspace of aqueous solutions of soy protein isolates were evaluated. Many corresponding odorants were identified by correlating GCO with GC/mass spectrometry (MS) on two separate stationary phases followed by comparing retention times, mass spectra, odor descriptions and odor intensities with authentic standards. Based on aroma extract dilution analyses, the most powerful odorants (strongest and most volatile first) were (1) dimethyl trisulfide, (2) trans,trans‐2,4‐ decadienal, (3) an unidentified burnt soy sauce‐like odor, (4) 2‐pentyl pyridine, (5) trans,trans‐2,4‐nonadienal, (6) hexanal, (7) an unidentified charred sweaty feet‐like odor, (8) acetophenone, and (9) 1‐octen‐3‐one. This is the first reported occurrence of dimethyl trisulfide in soy protein isolates.
Inactivation Kinetics of Lactobacillus plantarum by High Pressure Carbon Dioxide
Authors: Hong S.‐I. , Pyun Y.‐R.
Published: July 2006

Inactivation kinetics of Lactobacillus plantarum by high pressure CO2 was investigated to understand the mechanism of microbial inactivation. The inactivation rates increased with pressure, temperature and exposure time, and with decreasing pH of media. Microbial inactivation was governed essentially by penetration of CO2 into cells and its effectiveness could be improved by the enhanced transfer rate. Microbial reduction of 8 log cycles was observed within 120 min under CO2 pressure of 70 kg/cm2 at 30°C. We hypothesized that the cell death resulted from the lowered intracellular pH and damage to the cell membrane due to penetration of CO2. Pressurized CO2 treatment is a potential nonthermal technology for food preservation.
Treatments for Prevention of Persistent Pinking in Dark‐Cutting Beef Patties
Authors: Moiseev I. V. , Cornforth D. P.
Published: July 2006

Food‐grade oxidants and browning agents were compared for prevention of undesirable raw appearance of cooked dark‐cutting (DC) beef patties. DC beef had higher pH (6.6 vs 5.7) and lower 24h oxidation‐reduction potential (–190 vs –108 mV) than controls, with higher cooked yield and cohesiveness, but lower beef flavor intensity scores. DC patties with lactic acid (LA) had acceptable cooked appearance and increased myoglobin (Mb) denaturation during cooking (77%‐LA; 63%‐normal control; 41%‐DC control), but a tangy off‐flavor. Calcium peroxide increased Mb denaturation to 69%, but caused excessive oxidation. Caramel color eliminated undercooked appearance without increasing Mb denaturation, but raw and cooked patties were dark.
Rheological and Sensory Properties of Reduced‐Fat Processed Cheeses Containing Lecithin
Authors: Drake M. A. , Truong V. D. , Daubert C. R.
Published: July 2006

Reduced fat processed cheeses were prepared with granular or hydrogenated soy lecithin. Trained sensory panelists (n = 11) determined that reduced‐fat cheeses containing lecithin were more similar in texture attributes to full‐fat control cheeses than reduced fat cheeses without lecithin (P<0.05). Consumer flavor and acceptance scores (n =60) for cheeses with lecithin were not different from control cheeses, but texture acceptance scores for cheeses with lecithin were higher than scores for reduced fat control cheeses (P.0.05). Cheeses containing lecithin were less elastic than reduced fat control cheeses as determined by sensory panels and instrumental percent creep recovery. Lecithin improved processed cheese texture without negatively affecting acceptance.
Quality of Strawberries Packed with Perforated Polypropylene
Authors: Sanz C. , Pérez A.G. , Olías R. , Olías J.M.
Published: July 2006

Perforated polypropylene packages were used to study the effects of perforation on gas concentration and strawberry quality. Strawberry packages with perforations, and treated by simulating transport and shelf‐life conditions, developed an internal atmosphere with composition close to that recommended for this fruit. This controlled decay and reduced deterioration, thus extending strawberry postharvest life. Moreover, fruit ripeness degree and nutritional value were better preserved, although this modified atmosphere packaging seemed to reduce fruit color and lead to off‐flavor development.
Protein Denaturation and Emulsifying Properties of Plasma and Granules of Egg Yolk as Related to Heat Treatment
Authors: Le Denmat M. , Anton M. , Gandemer G.
Published: July 2006

Solubility, electrophoresis, viscosity and emulsifying properties of heated solutions of yolk, plasma and granules were determined. Plasma and yolk were not affected when heated under 69°C. Above 69°C, protein solubility dropped sharply and apparent viscosity rose sharply because of aggregation of proteins. For granules, protein solubility and apparent viscosity were not modified up to 76°C. The constituents of granules were not denatured. Emulsifying activity of yolk and plasma decreased after heating at 72°C but remained steady for granules. Emulsion stabilization properties of yolk, plasma and granules were not influenced up to 76°C. Results suggested that intact granules withstood more severe heat treatments than egg yolk without lessening their emulsifying properties.
Development of Color Indicators for Kimchi Packaging
Authors: Hong Seok‐In , Park Wan‐Soo
Published: July 2006

Color indicators for kimchi(fermented vegetable product) packaging were developed to monitor the quality of such commercial products during storage and distribution. Kimchiwas packed in a polypropylene (PP) tray with nylon/cast polypropylene (Ny/CPP) lid. A color indicator film consisting of PP resin, Ca(OH)2 as a CO2 absorbent and bromocresol purple or methyl red was attached to the lid. During fermentation at 0,10, and 20°C, kimchi quality was evaluated for pH and titratable acidity (TA), which had been correlated with Hunter color values of the indicators. Regardless of fermentation temperature, the color values correlated well with pH and TA values.
Kinetic Studies of Oxygen Dependence During Initial Lipid Oxidation in Rapeseed Oil
Authors: Andersson K. , Lingnert H.
Published: July 2006

Lipid oxidation was studied in rapeseed oil, stored at 35 or 50°C in 0.03, 0.3, 1.0 or 1.8% oxygen for 42 days. Peroxide value (PV), oxygen consumption, tocopherol consumption and production of volatile compounds were analyzed to follow the oxidation. At 50°C, lipid oxidation measured as oxygen consumption or PV was only slightly influenced by oxygen concentration ≥1%. Below 0.5% the influence was strongly enhanced. The production of volatiles showed different relationships to oxygen concentration and some compounds were produced in larger amounts at lower O2, than at higher O2, concentrations.
Physical Characteristics of Surimi Seafood as Affected By Thermal Processing Conditions
Authors: Shie J. S. , Park J.W.
Published: July 2006

Texture, color and microbiological characteristics of surimi seafood were measured at three processing temperatures (93°, 85°, and 75°C) and various times (0–120 min). The time required to provide a zero aerobic plate count at 93°, 85°, and 75°C was 5,15, and 15 min, respectively. Both thermal processing temperature and time affected whiteness and shear strain of surimi seafood. As the thermal processing temperature and time increased, the shear strain and whiteness decreased. The higher the thermal processing temperature and longer time, the lower were the shear strain and whiteness. Results indicated 15 min at 75° or 85°C were the optimum thermal processing conditions.
Rheological Characteristics of Fibrinogen‐Thrombin Solution and Its Effects on Surimi Gels
Authors: Yoon W.B. , Kim B.Y. , Park J.W.
Published: July 2006

Gel enhancing effects of fibrinogen‐thrombin on surimi were investigated using failure stress and analyzed by mixture design. Gelation time of fibrinogen‐thrombin mixture (20:1) gradually decreased as temperature increased from 5 to 40°C, whereas the G′ and G″ values continued to decrease up to 30°C and then increased at >30°C. Low quality surimi produced higher textural values (stress and strain) when fibrinogen and thrombin mixture (3–5%) had been added. Nonlinear stepwise regression model showed no significant interaction effects between surimi and fibrinogen‐thrombin mixture. However, the response trace plot showed that failure stress value of surimi gel was increased by the concentration of fibrinogen‐thrombin, but decreased by water content.
Reproducible Texture Analysis of Potato Chips
Authors: Segnini S. , Dejmek P. , Öste R.
Published: July 2006

An Instron punch test with three point support of a potato chip was developed, and factors affecting the results were evaluated. Individual potato chips were fried in palm oil in a forced circulation glass container, and their moisture content and texture were determined. Sample handling parameters contributing most to variability of moisture and texture were the cutting device, and position of the sample within the tuber. For oil temperatures 140 and 180°C, and two potato specific gravities, moisture and texture changes were studied during frying. Maximum force of break was in the 2–4% moisture region. Individual chips showed highly variable room temperature adsorption/desorption.
Shelf‐Life Extension of American Fresh Ginseng by Controlled Atmosphere Storage and Modified Atmosphere Packaging
Authors: Jeon B. S. , Lee C. Y.
Published: July 2006

American ginseng roots were treated with an antimicrobial agent, and stored under various CA (2,5, and 8% CO2) or MA conditions to extend the shelf‐life. Changes in respiration rates during CA storage, gas composition in packages, saponin and free sugar content, and other quality factors were monitored during storage. The respiration rate of ginseng increased rapidly during the first month of high CO2 CA storage and then slowly decreased to stable levels after 3 mo storage. In MA studies, the equilibrium CO2 concentration was attained after 20 days. There were no noticeable changes in appearance, saponin content and free sugars after 3 mo CA (5% CO2) storage and MA packages.
Histamine Formation and Bacterial Spoilage of Albacore Harvested off the U.S. Northwest Coast
Authors: Kim S. H. , An H. , Price R. J.
Published: July 2006

Iced and previously frozen albacore were monitored for histamine formation and bacterial growth during storage at 0–37°C. The optimum temperature for histamine formation in albacore tuna (Thunnus alalunga) was 25°C, and whole fish were more susceptible to histamine formation than dressed fish at that temperature. Storage at 25°C resulted in the highest histamine level, 60.4 mg/100g in whole fish stored for 7 days. When albacore were frozen prior to storage, reduced amount of histamine was found at 7.14 mg/100 g after 7 day storage at 25°C, only after decomposition became obvious. No histamine was found in any of the albacore samples stored in ice for 18 days.
Proteolysis in Cheese Curd as Affected by Subcellular Fractions fromLactococcus, LactobacillusandPropionibacterium
Authors: Pripp A.H. , Stepaniak L. , Sørhaug T.
Published: July 2006

Intracellular fraction (IF) and cell wall‐associated fraction (CWAF) from lactococci, lactobacilli and propionibacteria were added to cheese curd slurries according to a mixture design. Response surface and estimation of Scheffe's polynomial revealed synergistic interaction effects between lactococci and lactobacilli on secondary proteolysis determined by an o‐phthaldialdehyde assay. IFs from propionibacteria had a lower proteolytic activity than those from lactococci and lactobacilli used. Principal component analysis of capillary electropherograms of the trichloroacetic acid‐soluble fraction, discriminated between slurries treated with IFs and CWAFs. It also showed an effect of proteolytic enzymes from the IF of propionibacteria together with IFs from lactococci and/or lactobacilli, on small changes in overall peptide profile.
Carbon Dioxide Inhibition of Escherichia coli and Staphylococcus aureus on a pH‐adjusted Surface in a Model System
Authors: Kimura B. , Yoshiyama T. , Fujii T.
Published: July 2006

Growth of Escherichia coli and Staphylococcus aureuson the surface of Trypticase Soy Agar (TSA) packaged with various CO2 partial pressures (0, 20, 40, 60, 80, 100%, balance N2) was compared to the control (N2 100%) on TSA in which the pH was adjusted to equal that in CO2 atmospheres at 15°C and 30°C. At 15°C, the biostatic effect was noted with all CO2 partial pressures for both species. At 30°C, the biostatic effect of CO2 was almost completely nullified for E. coli, but that for S. aureus was still effective. S. aureus was more sensitive to the inhibitory effects of CO2 than E. coli at both the temperatures.
Sensory Quality and Lipid Oxidation of Maize Porridge as Affected by Iron Amino Acid Chelates and EDTA
Authors: Bovell‐Benjamin A C. , Allen L H. , Frankel E N. , Guinard J‐X
Published: July 2006

Iron fortification could reduce the high prevalence of iron deficiency in countries where diets are cereal‐based. The sensory quality and storage stability of iron‐fortified maize were evaluated by descriptive analysis and hexanal production. Porridge was prepared from maize either unfortified or fortified with 30 or 60 mg iron/kg as ferrous sulfate, bisglycinate, trisglycinate, or NaFeEDTA, then stored at 30,40 or 50°C for 20 days. Fifteen judges, trained in descriptive analysis rated the intensity of 20 sensory attributes of 28 samples. Hexanal production was measured by static headspace gas chromatography. Bisglycinate produced the most rancidity. Iron fortification with bisglycinate lowered the sensory quality and storage stability of maize.
Inactivation of Nisin by Glutathione in Fresh Meat
Authors: Rose N.L. , Sporns P. , Stiles M.E. , McMullen L.M.
Published: July 2006

Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) was used to determine the fate of nisin in meat products. Nisin in 0.02N HCl was added to fresh and cooked meat and meat juice and samples were stored at 4 °C overnight. Residual nisin solutions and meat juice and meat extract supernatants were analyzed for antimicrobial activity and for nisin. Nisin was recovered from cooked meat extract and cooked meat juice; however, only nisin bound to a food component was detected in fresh meat extract. Mass spectra for raw meat and juice showed a signal 307 Da greater than the mass of nisin. Results indicated that nisin was likely inactivated in raw meat by an enzymatic reaction with glutathione.
Tofu Yield and Textural Properties from Three Soybean Cultivars as Affected by Ratios of 7S and 11S Proteins
Authors: Ji M.P. , Cai T.D. , Chang K.C.
Published: July 2006

Crude 11S and 7S proteins of three soybean cultivars were fractionated, and tofu was prepared from soymilk with 11S/7S protein ratios of 1.6 to 3.2. Higher 11S/7S ratio produced lower yield (p≤0.05) of Vinton and Sturdy tofu. Higher 11S/7S ratio resulted in higher firmness of Proto and Sturdy tofu. Increase in 11S/7S ratio increased cohesiveness of Sturdy tofu. The maximum extent of decreasing Vinton tofu yield and increasing Proto and Sturdy tofu firmness was ∼10% of the unmodified tofu. Results indicated that tofu characteristics were cultivar dependent and manipulation of 11S/7S ratio may not result in substantial effects on tofu yield or quality.
Purification and Characterization of Alkaline Proteinase from Atlantic Menhaden Muscle
Authors: Choi Y.J. , Lanier T.C. , Lee H.G. , Cho Y.‐J.
Published: July 2006

Two alkaline proteinases (A and B) were isolated and found to be composed of homogeneous subunits. These proteinases, A and B, were concentrated 62.9‐and 986.5‐fold compared to the crude muscle extract, with molecular weights of 707,000 and 450,000, respectively. Both are probably serine type proteinases, and optimum caseinolytic activity was shown at pH 8.0 and 55 °C. Both degraded actomyosin under similar conditions. Enzyme A had higher thermal stability than B. The residual activities of A and B in 3.6% NaCl solution were 95% and 85%. These data suggest that these proteinases are involved in the softening of menhaden surimi gels which occurs during heating at 50 to 70 °C.
Pressure‐induced Denaturation of Muscle Proteins and its Prevention by Sugars and Polyols
Authors: Ashie I.N.A. , Lanier T.C. , MacDonald G.A.
Published: July 2006

Muscle tissues from four fish species (poikilotherms) that originated from different habitats and from beef (homeotherm) were subjected to pressures, ranging from 50 to 200 MPa, with or without pressure‐shift freezing. The extent of denaturation was measured as residual Ca2+‐ATPase activity. The ability of various sugars and polyols to protect the proteins from denaturation was also evaluated. Stability of proteins from the different species seemed to vary primarily according to body/habitat temperature. Sugars and polyols increased muscle protein stability, and sorbitol was the most effective. The degree of protection was, however, markedly reduced during pressure‐assisted freezing.
Formation of 2‐Pentyl Pyridine During Processing of Soybean Protein Isolates as Affected by pH
Authors: Zhou A. , Boatright W.L.
Published: July 2006

Levels of 2‐pentyl pyridine (2‐pp) in protein fractions from Stressland soybeans increased to 0.868 ppm (±0.027) at pH 7 after removing insoluble components from defatted flours. If similar protein fractions were held at pH 4.5 or pH 9, the 2‐pp concentration was 0.182 ppm (± 0.003) or 0.199 ppm (± 0.003), respectively. Soybean cultivars KS4694, Edison, and a type null for lipoxygenase 1, 2, and 3 showed similar changes. The increase at pH 7 occurred in less than 1 h. If the defatted flour solution was not subjected to alkaline extraction to remove insoluble components, the increase of 2‐pp at neutral pH did not occur. Thus, the pH conditions should be carefully controlled to produce soybean protein isolates with desired flavor properties.
Conjugated Linoleic Acid Content of Cheddar‐type Cheeses as Affected by Processing
Authors: Lin H. , Boylston T.D. , Luedecke L.O. , Shultz T.D.
Published: July 2006

Samples were taken at 9 stages of processing, from raw milk to cheese aged for 6 mo. Fatty acid distributions, conjugated linoleic acid (CLA), moisture, protein, lipid contents, and titratable acidity were determined. CLA contents were highest after 3 mo, with one type of Cheddar (3.76 mg/g lipid) higher than the other two (3.44 and 3.47 mg/g lipid). Multiple linear regression showed all composition parameters were directly related to CLA content (mg/100 g sample). The content of oleic acid isomer C18:1ω7 was also directly related to CLA content (mg/g lipid). Thus, content of CLA in Cheddar‐type cheeses might be controlled by stage and conditions of processing. An understanding of the effects of processing on CLA formation in Cheddar‐type cheeses will be beneficial in designing processing methods to enhance CLA contents.
Growth of Bacillus cereus on Oil‐blanched Potato Strips for “Home‐style” French Fries
Authors: Doan C.H. , Davidson P.M.
Published: July 2006

Fresh cut, oil blanched strips from whole potatoes stored at 7 or 13 °C were inoculated with approximately 3 or 5 log CFU/g Bacillus cereus and incubated at 21 or 26.7 °C for up to 9 h to model handling of “home‐style” French fries. Whole potato storage at 13 °C and incubation at 26.7 °C resulted in faster growth than 7 or 21 °C. Frying (2 to 3.5 min at 185 °C) inactivated up to 5.1 log B. cereus spores. Oil blanched potato strips for “home‐style” French fries should be stored at £ 21 °C or finish fried or discarded within 3 to 4 h.
In Vitro Digestion/Caco‐2 Cell Culture Model to Determine Optimal Ascorbic Acid to Fe Ratio in Rice Cereal
Authors: Glahn R.P. , Lee O.A. , Miller D.D.
Published: July 2006

The objectives were to determine if adding ascorbic acid (AA) to rice cereal enhanced iron availability, and if so, the best ratio of AA to Fe to maximize Fe availability. Also, we sought to determine whether mixing rice cereal with apple juice fortified with AA, compared to mixing it with water, would increase Fe availability. An in vitro digestion/cell culture model was used. Iron availability was increased at an AA:Fe molar ratio of 0.8:1 and maximal at 1.6:1. Mixing apple juice with rice cereal to approximate an AA:Fe ratio of 1.2:1 did not enhance Fe availability. Results indicate that factors in the apple juice offset any enhancement effects of AA on Fe availability.