bluuebunny/crossref_metadata_2025 huggingface dataset:
Postmortem Changes in Black Skipjack Muscle During Storage in Ice
Authors: Mazorra‐Manzano M.A. , Pacheco‐Aguilar R. , Díaz‐Rojas E.I. , Lugo‐Sánchez M.E.
Published: July 2006

Quality characteristics of black‐skipjack (Euthynnus lineatus) muscle kept in ice were evaluated by monitoring changes in chemical, microbiological, and sensory parameters over a 24‐d storage period. The K value increased linearly (r2= 0.966) from < 20% before d 3 to 75% at d 18. Muscle pH fluctuated between 5.7 to 6.0. Histamine did not exceed 50 ppm, while putrescine and cadaverine were < 40 ppm. Lipid deterioration was rather low with TBA values of 5 mg/100g at d 18. Descriptive sensorial evaluation indicated excellent‐to‐good attributes at d 6 and good‐to‐acceptable at d 18. Sensory assessment and K value gave the highest correlation with storage time, indicating a shelf life of 18 d.
A New Approach for the Determination of Fish Freshness by Electrochemical Impedance Spectroscopy
Authors: Niu J. , Lee J.Y.
Published: July 2006

Changes in several dielectric parameters of carp, herring and sea bass during their storage after death at 4 °C, 15 °C and 25 °C were examined by electrochemical impedance spectroscopy (EIS) in the frequency range of 0.1 Hz to 100 kHz. This method offers a simple, rapid and in situ measurement of the onset of spoilage. The phase angle and admittance changes are the best freshness indicators, from which four classifications of freshness may be defined for all of the tested fish species. Warburg‐type impedance and CE (chemical reaction preceding an electrochemical reaction) processes were observed in the relaxation process during storage and a proposed equivalent circuit satisfactorily described the overall electrochemical behavior.
Influence of NaCl and CaCl2 on Cold‐Set Gelation of Heat‐denatured Whey Protein
Authors: Bryant C.M. , McClements D.J.
Published: July 2006

Heat‐denatured whey‐protein isolate (HD‐WPI) solutions were prepared by heating a 10 wt% WPI solution (pH 7) to 80 °C for 10 min and then cooling it back to 30 °C. Cold‐set gelation was initiated by adding either NaCl (0 to 400 mM) or CaCl2 (0 to 15 mM). Both salts increased the turbidity and rigidity of the HD‐WPI solutions. Gelation rate and final gel strength increased with salt concentration and were greater for CaCl2 than NaCl at the same concentration because the former is more effective at screening electrostatic interactions and can form salt bridges.
Sensory, Shear, and Cooking Properties of Lower‐Fat Beef Patties Made with Inner Pea Fiber
Authors: Anderson E.T. , Berry B.W.
Published: July 2006

Lower fat (10% and 14%) ground beef patties containing inner pea fiber as dry powder or as part of a high fat mixture were compared to all‐beef patties (10%, 14%, and 18% fat). Patties processed with pea fiber had improved tenderness and cooking yields and showed less change in thickness during cooking, but required longer cooking times to reach 71 °C compared to all‐beef controls. Beef flavor intensity of pea fiber patties did not differ from 10% and 14% fat all‐beef patties. Different forms of pea fiber usage produced similar patty properties. Use of inner pea fiber in lower fat beef patties improved tenderness and cooking yield, without negative effects on juiciness and flavor.
Chlorine Generation and Disinfection by Electroflotation
Authors: Hernlem B.J. , Tsai L.‐S.
Published: July 2006

Electroflotation is a promising technology for simultaneous disinfection and removal of floatable constituents of food process water or fluid products. A bench‐scale electroflotation apparatus was constructed. The device demonstrated that disinfection was affected by the presence of chloride and the applied current. It was effective in disinfecting Escherichia coli when chloride was present at levels at least 5.6 mg L1 at 0.8 A but not at 0.1 A even with 260 mg L−1 chloride. Experiments on salt solutions showed that chlorine generation efficiency increased with chloride up to 260 mg L−1 and also with current, reaching a constant value above 0.4 A. Gas generation efficiency was relatively constant. Appropriate selection of operating conditions may allow optimization of disinfection and separation in electroflotation.
Mathematical Model for Prediction of Glass Transition Temperature of Fruit Powders
Authors: Khalloufi S. , El‐Maslouhi Y. , Ratti C.
Published: July 2006

Glass transition temperature (Tg) has been identified as a critical factor to predict quality of foodstuffs during processing or storage. Differential Scanning Calorimetry (DSC) was used to determine the Tg of 4 types of berry powders as a function of water content, and equilibrium moisture content was measured over different saturated solutions uusing the gravimetric method. The Guggenheim‐Anderson‐deBoer model was used to predict water activity (aw). Four models were tested for their ability to predict Tg as a function of the solid fraction. The combined effects of Tg and aw were incorporated into a new mathematical expression. The expression requires the determination of Tg (dry solids) of the product and data on equilibrium moisture sorption. The mean percent error of the model predictions is less than 3.6% when compared to experimental data.
Destruction of Yersinia enterocolitica by Lactobacillus sake and Pediococcus acidilactici During Low‐temperature Fermentation of Turkish Dry Sausage (sucuk)
Authors: Ceylan E. , Fung D.Y.C.
Published: July 2006

Effects of starter cultures, Lactobacillus sake and Pediococcus acidilactici, on the survival of Yersinia enterocolitica were studied in Turkish dry sausage (sucuk). Inoculated Y. enterocolitica (approximately 5.0 log CFU/g) was eliminated completely in sausages by L. sake (about 7.0 log CFU/g) and P. acidilactici (about 7.0 log CFU/g) by the 3rd d of fermentation but was not totally eliminated in natural fermentation without starter(s) after completion of 4 d of fermentation and 12 d drying (p < 0.05). pH decreased from 6.3 to about 4.7 in starter culture treatments and from 6.3 to 5.6 in natural fermentation after completion fermentation and drying (p < 0.05).
Stability of Retinyl Palmitate During Cooking and Storage in Rice Fortified with Ultra RiceTM Fortification Technology
Authors: LEE J. , HAMER M.L. , EITENMILLER R.R.
Published: July 2006

Rice fortified with Ultra RiceTM (UR) containing retinyl palmitate (RP) was tested as a potential vehicle for vitamin A delivery. After UR was mixed with a long grain rice at the ratio of 1 to 99 (w/w), the stability of RP in the rice mixture was studied during cooking and storage for 6 mo. After cooking, the percent retention range of RP was 75 to 87, depending upon the cooking methods. The stability of RP in the rice stored at 2 different temperatures and relative humidities (RH) appeared to be more affected by temperature than RH. Therefore, under tropical conditions, rice fortified with RP might require special handling to avoid significant RP losses.
Postmortem Biochemical and Functional Characteristic of Monterey Sardine Muscle Stored at 0 °C
Authors: Pacheco‐Aguilar R. , Lugo‐Sánchez M.E. , Robles‐Burgueño M.R.
Published: July 2006

Postmortem changes of sardine muscle during 15 d storage at 0 °C were studied to evaluate its quality and functionality. No microbial deterioration was detected since trimethylamine and histamine concentration remained low with final values of ≤ 1.62 mg/100g and 0.00018 ppm, respectively. A final proteolytic activity ≤ 20 μg Tyrosine/min/g protein was detected. Lipid oxidation from moderate to advanced was detected after day 5 with values of 31.8 to 33.9 meq/kg and 26 mg/kg for peroxide value and thiobarbituric acid value respectively. Muscle protein showed no gel‐forming ability. Extraction of myofibrillar protein decreased 45% and 81% at day 5 and 15 respectively. Overall results indicated that good quality was maintained during the storage period with a final K value of 50.7% when proper handling practices were implemented.
Influences of Gums, Soy Protein Isolate, and Heating Temperatures on Reduced‐Fat Meat Batters in a Model System
Authors: Lin K.‐W. , Mei M.‐Y.
Published: July 2006

Effects of incorporation of iota‐carrageenan, sodium alginate (AL), and soy protein isolate (SPI) in comparison with control (CONT) on the textural and physicochemical properties of reduced‐fat (15%) meat emulsions heated to various internal temperatures were investigated. Lower percent fat and water losses for treatments containing gums or soy protein isolate than those of CONT indicated that addition of gums and soy protein isolate could improve emulsion stability. AL had the greatest water‐holding capacity at the higher endpoint temperatures (76.7 °C and 82.2 °C), which was possibly due to the formation of a heat‐stable alginate gel. The SPI had the highest concentration of salt‐soluble protein in either raw or cooked meat batter.
Measurement of the Yield Stress of Protein Foams by Vane Rheometry
Authors: Pernell C.W. , Foegeding E.A. , Daubert C.R.
Published: July 2006

The yield stresses of protein foams made from varying protein types (spray dried egg white and whey protein isolate), protein concentrations, whip times, and mixer models were evaluated using vane rheometry. Two methods of analysis (point and slope methods) were investigated. Yield stress values determined by slope and point methods were similar for egg white protein foams but did not agree in the analysis of whey protein foams. Point method values were very reproducible in all foams tested. Egg white protein solutions formed stiffer foams more rapidly and at lower protein concentrations than foams made from whey protein isolate. Vane rheometry was shown to be a reliable method of determining yield stress in protein foams.
Electrical Conductance Study of Fluid Motion and Heat Transport During Starch Gelatinization
Authors: Karapantsios T.D. , Sakonidou E.P. , Raphaelides S.N.
Published: July 2006

An electrical conductance technique was employed with remarkable success in investigating the water dispersion during the gelatinization of starch suspensions. Water dispersion was realized by instantaneous conductance time records of the electrically accessible water in the samples. Different pasting procedures were examined and it was shown that problems with fluid motion and heat transport could strongly influence the water dispersion upon gelatinization. Furthermore, it was found that, under well mixed conditions at low shear, the water distribution at the end of gelatinization did not depend either on the employed heating rates or temperatures, thus implying that conductance measurements may have the potential to accurately quantify the extent of gelatinization.
Combined Pressure—temperature Inactivation of Alkaline Phosphatase in Bovine Milk: A Kinetic Study
Authors: Ludikhuyze L. , Claeys W. , Hendrickx M.
Published: July 2006

A detailed kinetic study on pressure‐temperature inactivation of alkaline phosphatase has been performed in the pressure range 0.1 to 725 MPa at temperatures between 25 and 63 °C. Inactivation could be accurately described by a first order kinetic model, allowing D‐values to be calculated. According to the thermal death time terminology, zr‐ and zp‐values were calculated, expressing temperature and pressure dependence respectively. However, at high temperature, pressure dependence could not be calculated unambiguously. D‐values firstly increased with increasing pressure up to 300 MPa and then decreased with further pressure increase, showing thermal inactivation to be counteracted by low pressure. Finally, a global model describing the D‐value as a function of pressure and temperature has been formulated.
Texture Assessment of French Cheeses
Authors: Antoniou K.D. , Petridis D. , Raphaelides S. , Omar Z. Ben , Kesteloot R.
Published: July 2006

The texture of a variety of French cheeses was studied by examining their compositional and mechanical parameters. The data obtained were correlated to those derived from a panel assessment of the sensory textural attributes of the samples. Statistical treatment of the results employing cluster analysis, analysis of variance, and redundancy analysis revealed that the most influential objective variables to characterize the cheese texture are the dry matter content and the resistance to force compression at 10% deformation of the initial sample height. These variables were highly correlated with sensory attributes such as hardness, brittleness, cohesiveness, and adhesiveness.
Combination Effects of Microbial Transglutaminase, Reducing Agent, and Protease Inhibitor on the Quality of Hairtail Surimi
Authors: Jiang S.‐T. , Hsieh J.‐F. , Ho M.‐L. , Chung Y.‐C.
Published: July 2006

A combination of microbial transglutaminase (MTGase), reducing agent and protease inhibitor was employed to improve the quality of underutilized fish surimi. SDS‐PAGE indicated that cross‐linking of myosin heavy chain (MHC) occurred in MTGase‐contained samples, while MHC of samples without MTGase disappeared after 120 min incubation at 45°C. Although the gel‐forming ability increased with MTGase added up to 0.6 unit/g, it was still too low to be commercially acceptable. However, the combined use of 0.1% NaHSO3, 0.01 mM transepoxysuccinyl‐L‐leucylamido‐(4‐guanidino)butane (E‐64) and 0.35 units MTGase/g substantially improved the quality of hairtail surimi. Based on this result, the combined use of E‐64, MTGase and NaHSO3 seemed to be a better way to improve gel‐forming ability of hairtail surimi.
Texture and Chemical Characteristics of Soy Protein Meat Analog Extruded at High Moisture
Authors: Lin S. , Huff H.E. , Hsieh F.
Published: July 2006

The relationships among extruder responses, texture, and protein solubility of soy protein meat analogs were studied. Soy protein isolate and wheat starch at 9:1 ratio were extruded at 60%, 65%, and 70% moisture contents and 137.8, 148.9, and 160°C cooking temperatures. The results showed that moisture content was a more important factor on the overall product texture than cooking temperature. Lower moisture content resulted in higher die pressure, harder texture, and lower total protein solubility. At a fixed moisture content, a higher cooking temperature resulted in a softer and less chewy product but only slightly changed the protein solubility. According to partial least square regression, the data from Texture Profile Analysis, protein solubility, and extruder responses correlated well and could be used to predict each other.
Volatiles and Oxidative Changes in Irradiated Pork Sausage with Different Fatty Acid Composition and Tocopherol Content
Authors: Jo C. , Ahn D.U.
Published: July 2006

Aerobic‐packaged sausage irradiated at 4.5 kGy had higher (P < 0.05) 2‐thiobarbituric acid reactive substances (TBARS) than those irradiated at 0 or 2.5 kGy at 0‐d storage. Generally, TBARS of aerobic‐ or vacuum‐packaged sausage prepared with lard were higher (P < 0.05) than those of sausage prepared with flaxseed oil or corn oil. The amount of 1‐heptene and 1‐nonene increased (P < 0.05) with increased irradiation doses. Aldehydes, ketones, and alcohols were not influenced by irradiation at 0‐d storage. However, irradiation accelerated lipid oxidation and increased the amount of aldehydes, ketones, and alcohols in aerobic‐packaged sausage during storage. The tocopherol content in the sausage influenced (P < 0.05) production of volatiles at different levels of unsaturated fatty acids.
Exogenous Polyamines and Gibberellic Acid Effects on Peach (Prunus persica L.) Storability Improvement
Authors: Martínez‐Romero D. , Valero D. , Serrano M. , Burló F. , Carbonell A. , Burgos L. , Riquelme F.
Published: July 2006

Peaches (Prunus persica L., cv. Babygold 6) harvested at the stage of commercial ripening were pressure‐infiltrated with putrescine (1 mM) or GA3 (100 mg L‐1) and then stored at 2°C for 14 d. Both treatments increased fruit firmness, putrescine‐treated peaches being significantly firmer than control ones. Treatments were also effective in reducing the susceptibility of the fruit to be damaged by mechanically compression with lower volume and surface of the damage zone. Ethylene emission and the respiration rate were reduced in treated fruits, which reflects a delay of the ripening process. The effects of the mechanical stress could be related to increased spermidine levels, rather than ethylene emission and respiration rate during storage.
Comparison Of Air‐blast And Pressure Shift Freezing On Norway Lobster Quality
Authors: Chevalier D. , Sentissi M. , Havet M. , Bail A. Le
Published: July 2006

Pressure shift freezing (PSF, 200 MPa, –18 °C) of whole Norway lobster was compared with air‐blast freezing and with pressurized samples (200 MPa, 5 °C) without freezing for its effect on the quality in texture, structure, water, and salt soluble protein extractabilities. For the pressurized Norway lobster meat either with PSF or without freezing, toughness increased while salt soluble protein extractability decreased. Conversely, air‐blast freezing did not affect the textural quality of the meat. Scanning electron micrographs showed that PSF yielded smaller ice crystals than air‐blast freezing.
Nondestructive Methods to Evaluate Maturity Level of Oranges
Authors: Olmo M. , Nadas A. , García J.M.
Published: July 2006

The maturity on the tree and the ripening during postharvest of 2 orange varieties (Citrus sinensis, cvs. Lanelate and Valencia) were evaluated, using 3 methods: the ratio soluble solids/titratable acidity (Maturity Index); the firmness, by hand densimeter, and the skin color with a portable colorimeter. The values of Color Index (1000a*/L*b*) and firmness complement each other for defining the maturity of tree fruit. Color and Maturity Indices are not correlated with time or weight losses during storage (8 °C) or with shelf life (20 °C). Firmness and weight loss are significantly (P < 0.05) correlated with each other, and both of them independently of each other, with postharvest time.
Concise Reviews and Hypotheses In Food Science
Authors: Fennema Owen R.
Published: July 2006

Coverage of all aspects of food science—including safety and nutrition–with in‐depth coverage of a narrowly defined topic, embodying careful evaluation of all pertinent studies, with interpretations and conclusions.

Also including hypothesis papers in pioneering areas of research or important areas that are afflicted by scientific controversy
Enrichment of Genistein in Soy Protein Concentrate with b‐glucosidase
Authors: Pandjaitan N. , Hettiarachchy N. , Ju Z.Y.
Published: July 2006

Genistein has been reported to have the most potent anticarcinogenic effect among isoflavones. Conversion of genistin in the glucoside form to genistein in the aglucone form by a b‐glucosidase enzyme hydrolytic activity during soy protein concentrate (SPC) preparation was evaluated. The optimum conditions for the conversion of genistin to genistein were pH 5.0, 50 °C incubation temperature, 2 units of enzyme/g of soy flour, 1 h incubation period, and 1:10 (w/v) defatted soy flour to water ratio. Under these conditions, 1.214 mg/g genistein were obtained in SPC and is significantly (p < 0.05) higher than the genistein content in SPC prepared under similar conditions without enzyme addition (0.845 mg/g).
Pore Structure of Coffee Beans Affected by Roasting Conditions
Authors: Schenker S. , Handschin S. , Frey B. , Perren R. , Escher F.
Published: July 2006

Hot‐air roasting of coffee beans not only forms color and flavor compounds but also leads to a complete alteration of the bean microstructure. The resulting pore structure controls mass transfer phenomena during roasting and storage. The principal objective of the present project was to investigate the influence of different roasting conditions on volume increase and pore‐structure development. Coffee beans were roasted in 2 different, well‐defined roasting processes to equal degree of roast. Volumetry, mercury porosimetry, and electron microscopy were employed to study structural product properties. The roasting conditions were found to have a major impact on microstructure. High‐temperature roasted coffees had greater bean volume, pore volume and larger micropores in the cell walls as compared to low‐temperature roasted beans.
Ultrasonic Spectroscopy Study of Salad Dressings
Authors: Chanamai R. , Alba F. , McClements D.J.
Published: July 2006

Ultrasonic velocity and attenuation spectra (1 to 100 MHz) of salad dressings with different disperse phase volume fractions (φ= 0 to 0.394) and mean droplet radii (0.3 to 0.6 μm) were measured at 25 °C. There were significant differences between the experimental measurements and theoretical predictions due to droplet flocculation. The measured attenuation coefficient was lower than expected at low frequencies because of thermal overlap effects, but it was greater than expected at high frequencies because of scattering. These deviations could be accounted for using an effective medium theory. Results suggest that ultrasonic velocities at 14 MHz were independent of droplet size and could be used to measure droplet concentration of salad dressings.
Gelling Properties of Whey Proteins After Enzymic Fat Hydrolysis
Authors: Blecker C. , Paquot M. , Deroanne C.
Published: July 2006

ABSTRACT: The effect of residual fat hydrolysis upon the gelation of whey protein concentrate (WPC) was studied. Gelling properties of a commercial WPC and lipase‐treated WPC were evaluated on the basis of least concentration endpoint gelation, penetration test, texture profile analysis and water‐holding capacity. Heat treatment of lipase‐treated WPC led to gels with the highest hardness, springiness, cohesiveness and water retention. Such transformed WPC could be advantageously used to help improve texture in formulated meat, bakery, and confectionery products.
Factors Affecting Premature Browning During Cooking of Store‐purchased Ground Beef
Authors: Killinger K.M. , Hunt M.C. , Campbell R.E. , Kropf D.H.
Published: July 2006

ABSTRACT: Storage conditions, patty location within packages, and purchase time effects on premature browning (PMB) of ground beef during cooking to 55 °C were determined. Packages were purchased twice daily. Patties were formed soon after purchase or after overnight storage (4 °C). Patties from the outer portion of the packages purchased in the morning were bright red and had the highest incidence of PMB (62.5%) when cooked. Patties from inner portions of packages purchased in the afternoon and refrigerated overnight were more (P < 0.05) purple and had the lowest incidence (25%) of PMB. Premature browning incidence averaged 47%. Consumer handling procedures affected PMB apparently by changing the state of myoglobin in the packages.
The Gloss of Edible Coatings as Affected by Surfactants, Lipids, Relative Humidity, and Time
Authors: Trezza T. A. , Krochta J.M.
Published: July 2006

ABSTRACT: Water‐based whey protein isolate (WPI) coatings had the same gloss as shellac and zein coatings cast from ethanol solutions and water‐based tapioca dextrin and hydroxypropyl methylcellulose (HPMC) coatings. For lipid dispersion coatings, the particle size of the dispersed phased influenced gloss values. WPI coatings had stable gloss values at 52%, 75%, and 95% relative humidity (RH). At 95% RH, shellac and zein coatings “blushed,” and both dextrin and HPMC coatings became tacky. WPI and shellac films maintained a high gloss after 7.6 mo of storage at 23 °C and 75% RH and had higher gloss than whey protein concentrate (WPC) and HPMC coatings. The type and level of surfactant added to WPI coatings greatly influenced gloss.
Water Vapor Permeability and Solubility of Films from Hydrolyzed Whey Protein
Authors: Sothornvit R. , Krochta J.M.
Published: July 2006

ABSTRACT: The effects of whey protein hydrolysis on film water vapor permeability (WVP) and solubility at 3 plasticizer levels were studied. Little or no significant difference (p > 0.05) appeared for film WVP between unhydrolyzed whey protein isolate (WPI), 5.5% degree of hydrolysis (DH) WPI and 10% DH WPI films at comparable plasticizer contents. However, increase in glycerol (gly) content significantly increased film WVP. Thus, reduction in WPI molecular weight (MW) through hydrolysis may be a better approach to improving film flexibility than addition of plasticizer. Both 5.5% and 10% DH WPI had significantly different (p ≤ 0.05) film solubility compared to unhydrolyzed WPI. Soluble Protein (SP) and total soluble matter (TSM) of hydrolyzed WPI films were much higher than for unhydrolyzed WPI films.
Thermal Inactivation Kinetics of Salmonella and Listeria in Ground Chicken Breast Meat and Liquid Medium
Authors: Murphy R.Y. , Marks B.P. , Johnson E.R. , Johnson M.G.
Published: July 2006

ABSTRACT: Thermal inactivation of Listeria innocua and 6 Salmonella serotypes in ground chicken breast meat was compared to that in peptone (0.1%) ‐ agar (0.1%) solution. Inoculated samples were packed in a thin‐wall metal tube and submerged in a water bath at temperatures ranging from 55.0 to 70.0 °C. For Salmonella and Listeria, the D values in ground chicken breast meat at 55 to 70 °C were higher (p < 0.0001) than those in peptone‐agar solution; however, the z values were not significantly different. Complete first‐order inactivation models, with Arrhenius temperature dependency, were developed for each inoculum and medium.
Contribution of Lactococcus lactis subsp lactis IFPL 359 and Lactobacillus casei subsp casei IFPL 731 to the Proteolysis of Caprine Curd Slurries
Authors: Parra L. , Casal V. , Gómez R.
Published: July 2006

ABSTRACT: Proteolysis was studied in low‐fat caprine curd slurries pre‐incubated (24 h at 30 °C) with an extra dose of rennet, 10.0 or 22.0 μg g‐1 (LR and HR slurries, respectively), and treated at 70 °C for 15 min prior to incubation with sonicated cells of Lactococcus lactis subsp lactis IFPL 359 alone or combined with Lactobacillus casei subsp casei IFPL 731. The addition of lactobacilli to slurries containing lactococci increased the conversion of water‐soluble nitrogen to nonprotein nitrogen and amine nitrogen. Major differences were found for some free amino acids, such as glutamic acid and proline, and hydrolysis of most hydrophobic peptides produced by lactococci, which are associated with bitterness in cheese.
Production of Kefir from Soymilk With or Without Added Glucose, Lactose, or Sucrose
Authors: Liu Je‐Ruei , Lin Chin‐Wen
Published: July 2006

ABSTRACT: The effects of added glucose, lactose, and sucrose on microbial growth, acid, and ethanol production, and galactosidase activity in soymilk fermented with kefir grains were studied. Immediately after the addition of kefir grains to soymilk, the lactic‐acid bacterial counts were higher, but the yeast counts were lower than in milk kefir. After fermentation for 32 h, the concentrations of yeast, lactic acid, and ethanol in soymilk were significantly lower than those in milk kefir. Addition of 1% glucose to soymilk stimulated growth of lactic‐acid bacteria and yeast, the production of lactic acid and ethanol, and the β‐galactosidase activity. Nevertheless α‐ galactosidase activity was suppressed by 1% glucose.
Tenderization of Heated Sliced Beef by Succinylated Glycerol Monostearate, a Novel Meat Tenderizer
Authors: Mori K. , Nishimura T. , Yasukawa T. , Takahashi K.
Published: July 2006

ABSTRACT Succinylated glycerol monostearate (SGMS) was most effective in reducing shear‐force value when used as a surfactant to tenderize meat using sheep casings as a model of intramuscular connective tissue. Roasted beef slices that had been treated with 2% granular SGMS showed a marked decrease in toughness due to the penetration of SGMS along the perimysium during heating. Collagen fibrils in the perimysium were transformed into a sheet‐like structure that seemed very likely to be a complex of SGMS and thermally denatured collagen. These structural changes could account for the tenderness of the roasted beef slices.
Isolation and Characterization of Virgin Olive Oil Phenolic Compounds by HPLC/UV and GC‐MS
Authors: Tasioula‐margari M. , Okogeri O.
Published: July 2006

ABSTRACT This research examined the phenolic fraction of extra virgin olive oil samples from Lianolia variety olives grown in the region of Preveza, Greece. Phenolic compounds were extracted from oil samples, separated by reversed‐phase high‐performance liquid chromatography (HPLC), and characterized by gas chromatography‐mass spectrometry (GC‐MS). Both simple and complex phenols were detected with the latter being the most abundant. 3–4‐Dihydroxyphenyl ethanol (hydroxytyrosol) and p‐hydroxyphenylethanol (tyrosol) predominated among the simple phenols. Complex phenolic compounds were further separated by preparative HPLC and analyzed by GC‐MS before and after hydrolysis. The presence of hydroxytyrosol and tyrosol derivatives was confirmed. Both derivatives were always present in greater quantities and made up an average exceeding 70% in all samples analyzed.
Preparation of Passion Fruit Puree by Flash Vacuum‐Expansion
Authors: Brat P. , Olle D. , Reynes M. , Cogat P.‐O. , Brillouet J.‐M.
Published: July 2006

ABSTRACT Purple passion fruit were processed by flash vacuum‐expansion in comparison with a single‐strength juice. A puree was obtained with about 50%/fruit weight yield, which is 2‐fold that obtained for the reference juice. Color and cell‐wall polysaccharides of the products were analyzed, and their rheological properties were investigated. The red‐purple puree was enriched in anthocyanins and alcohol‐insoluble residue. The puree had higher consistency and viscosity, which was related to its alcohol‐insoluble residue and starch contents.
Interaction between Emulsion Droplets and Escherichia coli Cells
Authors: Li J. , Mcclements D.J. , Mclandsborough L.A.
Published: July 2006

ABSTRACT Oil‐in‐water emulsions (20% n‐hexadecane, v/v) were stabilized by dodecyltrimethylammonium bromide (DTAB), Tween 20, or sodium dodecyl sulfate (SDS). Particle size distribution and creaming stability were measured before and after adding Escherichia coli cells to emulsions. Both E. coli strains promoted droplet flocculation, coalescence, and creaming in DTAB emulsions, although JM109 cells (surface charge = ‐35 mV) caused faster creaming than E21 cells (surface charge = ‐5 mV). Addition of bacterial cells to SDS emulsions promoted some flocculation and coalescence, but creaming stability was unaffected. Droplet aggregation and accelerated creaming were not observed in emulsions prepared with Tween 20. Surface charges of bacterial cells and emulsion droplets played a key role in emulsion stability.
Evaluation of Thin Agar Layer Method for Recovery of Heat‐Injured Foodborne Pathogens
Authors: Wu V.C.H. , Fung D.Y.C.
Published: July 2006

ABSTRACT The Thin Agar Layer (TAL) method of Kang and Fung 1998 was used to enumerate heat‐injured (55 °C for 10 min) foodborne pathogens. This method involves overlaying 14 mL of nonselective medium (Tryptic Soy Agar, TSA) onto a prepoured, pathogen‐specific, selective medium. The recovery rate with the TAL method was compared with the rate for TSA and pathogen‐specific, selective media. No significant differences occurred between TSA and TAL (P > 0.05) for enumeration of heat‐injured Escherichia coli O157:H7, Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, and Yersinia enterocolitica, and both recovered significantly higher numbers than selective media (P < 0.05). The TAL method is a 1‐step, convenient procedure for recovery of heat‐injured cells.
Characteristics of Imitation Cheese Containing Native Starches
Authors: Mounsey J.S. , O'riordan E.D.
Published: July 2006

ABSTRACT Imitation cheeses containing 3% native maize, waxy‐maize, wheat, potato or rice starch were manufactured and the microstructure, meltability, texture and dynamic rheology of these products were compared to a control (0% starch). Fat globules in starch‐containing products (except potato) were smaller than in the control as evidenced by electron microscopy. All starches reduced meltability and cohesiveness of the imitation cheeses. Hardness was increased by wheat, potato or maize starch but reduced by waxy‐maize or rice starch. Starches significantly reduced tan 8 peaks compared to the control with potato starch having the greatest effect. Rice starch appears to have the most potential as a partial casein substitute in imitation cheese.
Characterization of Pectins and Some Secondary Compounds from Theobroma cacao Hulls
Authors: Arlorio M. , Coisson J.D. , Restani P. , Martelli A.
Published: July 2006

ABSTRACT This paper describes the chemical characterization of cocoa hulls, a potential source of high‐methoxyl pectins (HMP). The content of some antinutritive compounds and potentially toxic compounds is also reported. Use of 2‐propanol is proposed for the preliminary clean‐up of the hulls and for the washing of the gel. Antinutritive and potentially toxic compounds seem not to limit the use of cocoa hulls. Lindane and ochratoxin A were easily removed together with fat using 2‐propanol during preliminary clean up. The pectins (partially purified, yield: 1.29 ± 0.08%) showed a high methoxylation degree (%DE) of 60.53 ± 6.09%, and a viscosity of 16,200 cPs (5 rpm 20 °C). Washing procedures permit the decrease of the gel acidity from pH 1.97 to pH 3.76.
Rheological Characterization of a Gel Formed During Extensive Enzymatic Hydrolysis
Authors: Doucet D. , Gauthier S.F. , Foegeding E.A.
Published: July 2006

ABSTRACT Extensive hydrolysis of whey protein isolate (WPI) by Alcalase 2.4L® caused a dramatic increase in turbidity and viscosity. A gel was formed after the degree of hydrolysis was ≥ 18%, coinciding with < 16%β‐lactoglobulin and < 4%α‐lactalbumin remaining unhydrolyzed. Heat‐induced and enzyme‐induced WPI gels were compared. Frequency and strain dependence indicated that both gels could be considered as strong, physical gels.
Textural Characterization of Cheeses Using Vane Rheometry and Torsion Analysis
Authors: Truong V.D. , Daubert C.R.
Published: July 2006

ABSTRACT Vane rheometry was applied to textural characterization of cheeses and compared with torsion analysis. A Haake VT 550 viscotester was used for both vane and torsion tests at strain rates of 0.003 to 0.524 s‐1. Angular deformation and shear stress in the vane test increased with increasing low strain rate and was rate independent at higher rates. This shear rate dependency of stress and deformation varied with cheese types. Shear stresses from the vane method were lower than torsion shear stresses. Similar texture maps of cheeses were generated by plotting stress and strain or angular deformation values from the 2 testing methods. The findings indicate the vane technique can be used for rapid textural characterization of cheeses.
Thermal Kinetics of Color Change, Rheology, and Storage Characteristics of Garlic Puree/Paste
Authors: Ahmed J. , Shivhare U.S.
Published: July 2006

ABSTRACT Kinetics of color change of garlic puree at selected temperatures and rheological behavior and effects of packaging materials and storage temperatures on color of garlic paste were investigated. Results indicated that color change during thermal processing of garlic puree followed first‐order reaction kinetics with an activation energy of 13.78 kJ/mol. Garlic paste behaved as a pseudoplastic material and flow activation energy at 100 rpm equaled 13.30 kJ/mol. Both temperature and duration of storage had effect (P≤ 0.05) on total color of garlic paste. Degreening of garlic paste was observed during storage at 25°C and complete degreening occurred at about 48 to 52 d. Storage of garlic paste at 5°C enhanced greening.
Solubilized Cellulose and Dehydrated Potato Extract in Cooked, Low‐fat Comminuted Beef
Authors: Katsanidis E. , Meyer D.C. , Epley R.J. , Addis P.B. , Ruan R.
Published: July 2006

ABSTRACT The optimal level of use of NP‐5, a dehydrated potato extract, and solubilized cellulose (SC), a highly functional form of cellulose in a comminuted beef product was determined so that water holding capacity (WHC), cooking yield and resistance to rancidity would be maximized. NP‐5 was a very effective antioxidant and water binding ingredient at 1.5%. Addition of SC resulted in a more moist product and improved the cooking yield compared to the control. Addition of NP‐5 and SC resulted in extended overall storage stability.
Effects of Carcass Weight Class and Postmortem Aging on Carcass Characteristics and Sensory Attributes in Grain‐Fed Veal
Authors: Mandell I.B. , Maclaurin T. , Buttenhan S.
Published: July 2006

ABSTRACT Thirty‐six Holstein bull calves were used to examine the effects of carcass weight and postmortem aging on carcass characteristics and sensory attributes of grain‐fed veal. Three carcass weight classes (hide‐on) included light (< 165 kg), medium (177 to 186 kg), and heavy (195 to 204 kg) with 12 animals per class. Postslaughter, longissimus (LM) and semimembranosus (SM) roasts were aged for 2, 7, and 14 d. Carcass characteristics were generally similar (P > 0.10) across weight class. Weight class did not affect (P > 0.10) tenderness in LM or SM or flavor in LM. Longissimus muscle from light weight carcasses were juicier (P < 0.07) than heavier carcasses while flavor was lower in SM for medium compared with heavy carcasses. Aging tended to increase (P < 0.100) tenderness attributes for LM and SM. Veal flavor increased (P=.014) with 7 d aging for LM. Postmortem aging should be considered for routine processing of veal to improve meat quality.
Standardization of the Ammonia Electrode Method for Evaluating Seafood Quality by Correlation to Sensory Analysis
Authors: Pivarnik L. , Ellis P. , Wang X. , Reilly T.
Published: July 2006

ABSTRACT: Ammonia ion‐selective electrode (ISE) measurements, reported as apparent ammonia, were correlated to expert sensory assessments of 6 different fish species stored on ice and at room temperature. Total volatile base nitrogen (TVB‐N), trimethylamine nitrogen (TMA‐N), and apparent ammonia showed the same development trend during storage. ISE measurements and TVB concentrations had a correlation of r2= 0.92. Sensory assessment, using a 1‐ to 100‐mm line scale with values > 50 considered unacceptable, resulted in an r2between sensory scores and ISE measurements of 0.78. Regression analysis predicted 19.6 mg/100 g of apparent ammonia in fish tissue at the sensory limit of 50, regardless of storage conditions. ISE measurements could be used in predicting borderline quality and decomposition.
Maintaining Quality of Fresh‐cut Tomato Slices through Modified Atmosphere Packaging and Low Temperature Storage
Authors: Hong J.H. , Gross K.C.
Published: July 2006

ABSTRACT: Quality of fresh‐cut tomato slices was compared during cold storage under various modified atmosphere packaging conditions. Chilling injury of slices in containers sealed with Film A was higher than with Film B; these films had oxygen transmission rates of 87.4 and 60.0 ml · h‐1· m‐2· atm‐1 at 5 °C and 99% RH, respectively. While slices in containers with an initial atmospheric composition of air, 4% CO2+ 1 or 20% O2, 8% CO2+ 1 or 20% O2, or 12% CO2+ 20% O2 showed fungal growth, slices in containers with 12% CO2+ 1% O2 did not. Low ethylene in containers enhanced chilling injury. Modified atmosphere packaging provided good quality tomato slices with a shelf life of 2 w or more at 5 °C.
Continuous Production of Pectic Oligosaccharides in an Enzyme Membrane Reactor
Authors: Olano‐Martin E. , Mountzouris K.C. , Gibson G.R. , Rastall R.A.
Published: July 2006

ABSTRACT: The use of high methylated (60% to 66% methylation) and low methylated (8% methylation) pectin for the continuous production of pectic‐oligosaccharides in an ultrafiltration dead‐end membrane reactor was investigated. Substrate concentration (1% to 5% w/v), enzyme concentration (90 to 2700 Ul‐1), and residence time (40 to 120 min) were the factors studied. Response surface methodology was used to model the processes. Two responses were determined: conversion of pectin(s) into product, and product dextrose equivalent values (DE). Mathematical models were fitted for each response. Conversions to product ranged from 67% to 99.7%. Product DE values increased with increasing residence time from 27 to 70. The average molecular‐weight distribution of the products obtained was 3.5 kDa when high methylated pectin was used as substrate and 3.8 kDa for low methylated pectin.
Temperature Profiles in a Cylindrical Model Food During Pulsed Microwave Heating
Authors: Yang H.W. , Gunasekaran S.
Published: July 2006

ABSTRACT: Cylindrical 2%‐agar gel samples were heated by pulsed and continuous microwave applications. The total microwave application time of 3 min was maintained for all experiments. Sample temperature was measured at various depths along the radial dimension to experimentally determine the internal temperature profile as a function of heating time. A local hot spot was observed at the center portion of the sample during the continuous microwave application. This hot spot was less significant during pulsed microwave applications, especially when longer intermittent power‐off times were employed. An implicit finite‐difference model was used to estimate temperature profiles within the sample during microwave heating. The estimated temperature profiles matched the experimental values well.
Physical and Chemical Properties of Edible Films Containing Nisin and Their Action Against Listeria Monocytogenes
Authors: Ko S. , Janes M.E. , Hettiarachchy N.S. , Johnson M.G.
Published: July 2006

ABSTRACT: The effects of hydrophobicity/hydrophilicity of edible films against Listeria monocytogenes strain V7 by various nisin concentrations (4.0 ‐ 160 IU/film disk) and pH values ranging from 2.0 to 8.0 were determined and the mechanical properties and water vapor permeability of films prepared with or without nisin were compared. Surface hydrophobicities (446, 282, 232 and 142, respectively) of whey protein isolates, soy protein isolates, egg albumen and wheat gluten were determined. As the nisin concentration increased, the amount of inhibition progressively increased in all tested films. Using nisin, edible films with higher hydrophobicity values of 280 to 450 units under an acidic environment exerted a greater inhibitory effect against L. monocytogenes. Different interactions of nisin with the proteins of the different films resulted in variation in the mechanical properties and water vapor permeabilities of the films tested.
Sensory Characteristics of Apple Juice Evaluated by Consumer and Trained Panels
Authors: Okayasuand H. , Naito S.
Published: July 2006

ABSTRACT: To identify sensory characteristics of unclarified apple juice and to compare unclarified and clarified types, 140 consumers and 10 trained panelists evaluated 16 commercial apple juice samples (4 clarified and 12 unclarified). Unclarified and clarified juices were clearly separated by the first principal component (PC1), whose main factor was fresh, green, and sweet aroma. It was difficult to predict consumer preference by regression models using trained panel preference and analytical attributes. Mapping consumers' overall preferences on a sensory profile made by PC1 and PC2, the consumer panel preferred apple juice with moderately increased fresh and green aroma and thoroughly decreased sour and astringent.
Evaluation of Some Binders and Fat Substitutes in Low‐fat Frankfurters
Authors: Yang A. , Keeton J.T. , Beilken S.L. , Trout G.R.
Published: July 2006

ABSTRACT: Sensory and Texture Profile Analysis (TPA) were used to evaluate the effects of 8 fat substitutes/binders on the quality of low‐fat frankfurters (10% fat) compared to both high‐fat (22%) products and low‐fat products without fat substitutes. Products with isolated soy protein (ISP), modified waxy maize starch, and isolated muscle protein (IMP) had similar sensory and texture properties to the high‐fat products, but the products with ISP and IMP had higher purge loss. Sensory and TPA properties were highly correlated: overall palatability was strongly associated with TPA first bite energy (r = 0.84) and fracturability (r = 0.800). Principal component analysis of the data showed that most of the variation in properties of the products was due to variation in firmness and cohesiveness (83.6%) of the sensory properties and stress‐related parameters from the force‐deformation curves for TPA (77.6%).
Chemical and Histological Characterization of Raw Muscle from Soft and Hard Crabs of Snow Crab Chionoecetes opilio
Authors: Mizuta S. , Kobayashi Y. , Yoshinaka R.
Published: July 2006

ABSTRACT: Chemical analysis showed soft snow crab muscle to have a higher water content and a lower protein content than hard crab muscle. Histological observations revealed frequent occurrences of disintegrated regions in muscle fibers and pericellular connective tissue of soft snow crab muscle tissue. Salinity of the free body fluid recovered from the meropodites of the soft snow crab was significantly higher than that of the hard snow crab. Sensory evaluation revealed differences in texture and taste between soft and hard crabs, which corresponded well to their compositional and histological differences.
Rheological Examination of White Pepper Slurries to Determine Prior Treatment of Pepper with Gamma‐Irradiation
Authors: Yi S.D. , Yang J.S. , Song K.B. , Chang K.S. , Oh M.J.
Published: July 2006

ABSTRACT: A study was carried out to examine rheological properties for the detection of irradiated white pepper by viscosity and maximum viscosity methods. Samples in polyethylene bags were irradiated and measured for apparent viscosity and maximum viscosity. The viscosity of all samples decreased with increasing stirring speeds and irradiation dose. This trend was similar for maximum viscosity. The results suggest that the detection of irradiated white pepper is possible by both the viscometric and maximum viscosity methods. Therefore, maximum viscosity method can be used as a new method to detect the irradiated white pepper.
Effect of Tissue Infrastructure on Electric Conductance of Vegetable Stems
Authors: Wang C.S. , Kuo S.Z. , Kuo‐Huang L.L. , Wu J.S.B.
Published: July 2006

ABSTRACT: This study measures the electric conductance and examines the microscopic structure of bamboo shoots, sugarcane, lettuce stem, and mustard stem. The electric conductance readings vary from 0.09 S/m to 0.72 S/m across the stem, and from 0.19 S/m to 0.46 S/m along the stem. The electric conductance along the stem is higher than the electric conductance across the stem in bamboo shoots and sugarcane, while the reverse is true in lettuce stem and mustard stem. The orientation of vascular bundles and the shape of parenchyma cells are proposed to account for the different conductance readings from the same vegetable in different directions. The orientation of vascular bundles appear to influence electric conductance more than the shape of parenchyma cells when both factors are present in the same time.
Effect of Thermal Treatment on Moisture Transport during Steam Cooking of Skipjack Tuna (Katsuwonas pelamis)
Authors: Bell J.W. , Farkas B.E. , Hale S.A. , Lanier T.C.
Published: July 2006

ABSTRACT: Moisture and mass loss were determined during atmospheric steam cooking of skipjack tuna by measurement of muscle moisture content in whole fish and on‐line measurement of mass and temperature in fillets. Thermal denaturation temperatures of muscle proteins were measured by differential scanning calorimetry. Muscle moisture content and mass loss were dependent on muscle temperature. Temperature distribution was predicted and mass loss rates were calculated in fillets. A decreasing rate of mass loss was followed by a steady rate period and a resumption of a decreasing rate period. The increased loss of mass during the steady period corresponded to thermal denaturation temperatures of muscle proteins. Changes in mass loss rates resulted from a gradient of muscle changes produced by the temperature gradient created during cooking.