bluuebunny/crossref_metadata_2025 huggingface dataset:
Gelation of Shark Meat under Mild Acidic Conditions: Physicochemical and Rheological Characterization of the Gel
Authors: Venugopal V. , Kakatkar A. , Bongirwar D.R. , Karthikeyan M. , Mathew S. , Shamasundar B.A.
Published: July 2006

Homogenate of washed shark meat in water was converted into a gel by lowering its pH to 3.5 by acetic acid. Unlike unacidified homogenate, water was strongly bound to the gel. The strength of the gel increased with increasing moisture content, while expressible water content was not affected. Gelation was associated with reduction in myosin heavy chain and sulfhydryl groups. Dynamic rheological measurements indicated viscoelastic nature of the gel. The storage modulus increased with increased temperature. The shear stress sweep of the gel dispersions as a function of temperature suggested pseudoplastic behavior.
Thermal Degradation Kinetics of Carotenoids and Visual Color of Papaya Puree
Authors: Ahmed J. , Shivhare U.S. , Sandhu K.S.
Published: July 2006

The degradation kinetics of carotenoids and visual color of papaya puree were investigated at selected temperatures (70 to 105°C). The concept of fractional conversion was applied to determine the kinetic parameters. The degradation of papaya color was based on change of Hunter a and b values and it was found that combination of Hunter (a × b) value adequately represented thermal color change. Degradation of carotenoids and visual color followed first order reaction kinetics. Dependence of the rate constant followed the Arrhenius relationship. The process activation energies for carotenoids and visual color were 20.56 and 32.59 kJ/mol respectively. Higher activation energy value indicated greater temperature sensitivity of visual color as compared to carotenoids. The degradation of pigment and visual color varied linearly. Visual color could therefore be used for on‐line quality control of papaya puree.
Control of Listeria monocytogenes on the Surface of Refrigerated, Ready‐to‐eat Chicken Coated with Edible Zein Film Coatings Containing Nisin and/or Calcium Propionate
Authors: Janes M.E. , Kooshesh S. , Johnson M.G.
Published: July 2006

ABSTRACT: This study investigated the effect of nisin added to zein film coatings (Z) coated onto ready‐to‐eat chicken against L. monocytogenes. L. monocytogenes inoculated chicken samples were dipped into Z dissolved in propylene glycol (ZP) or ethanol (ZE), with and without added nisin (N) (1000 IU/g) and/or 1% calcium propionate (CP) then stored at 4 °C or 8 °C for 24 d. After 16 d at 4 °C the growth of L. monocytogenes (6.8 log CFU/g) was suppressed by 4.5 to 5 log CFU/g and at 2.7 log CFU/g counts were maintained at a nondetectable level from day 0 to day 24 with ZEN, ZPNCP, or ZENCP. Zein film coatings with nisin can prevent the growth of L. monocytogenes on ready‐to‐eat chicken.
Consumer Acceptance of Whey‐protein‐coated as Compared with Shellac‐coated Chocolate
Authors: Lee S.‐Y. , Dangaran K.L. , Guinard J.‐X. , Krochta J.M.
Published: July 2006

ABSTRACT: Four formulations of whey‐protein‐isolate (WPI) coatings were used to coat chocolate‐covered almonds. Two formulations were without lipid and two were with lipid. The 2 WPI formulations without lipid varied in native‐ as compared with the heat‐denatured WPI amount. The 2 WPI formulations with lipid varied in the lipid amount. The shellac formulation consisted of 30% solids, of which 90% was shellac and 10% was propylene glycol. A central location consumer test was carried out for attributes such as overall degree of liking. The results strongly indicate that water‐based WPI‐lipid coatings can be used as an alternative glaze, with higher consumer acceptance than alcohol‐based shellac.
Method Development and Generation of Profiles for Selected Phenolics from Apple Cultivars Used for Processed Products
Authors: Russell L.F. , Wolfe L.I. , Ryan D.A.J.
Published: July 2006

ABSTRACT: Profiles of selected phenolic constituents of 2 apple cultivars, Northern Spy and Ida Red, commonly used for processed products were compared. Although chlorogenic acid was the principal phenolic in both cultivars, there were significant quantitative differences. A new solid‐phase extraction (SPE) and high‐performance liquid chromatographic (HPLC) separation using polymeric resins was developed for this experiment. Quantification was by ultra‐violet (UV) absorbance using a diode array detector. The performance of this new method was compared with that of a published liquid‐liquid extraction (LLE) method, based on linearity of detector response, limits of detection, reproducibility of analysis, and recoveries from spiked apple samples.
Opalescence in Australian‐grown Pecan Kernels: Occurrence and Causes
Authors: Wakeling L.T. , Mason R.L. , D'Arcy B.R. , Caffin N.A.
Published: July 2006

ABSTRACT: Opalescence is an unattractive browning of the interior of the pecan kernel compared to the white interior of normal kernels. The discoloration is due to the presence of free oil, resulting from decompartmentalization in the endosperm of opalescent pecans. Using a subjective scoring system, approximately 70% of Australian‐grown pecan kernels tested were found to exhibit opalescence to some degree. Evaluation of kernels for opalescence during the harvesting‐processing chain showed that opalescence first becomes evident in kernels after mechanical cracking. Opalescent kernels were found to have lower levels of calcium and higher amounts of oil compared to nonopalescent kernels. Differential scanning calorimetry showed that kernels do not freeze at ‐18 °C.
Transglutaminase Cross‐linking of Whey/Myofibrillar Proteins and the Effect on Protein Gelation
Authors: Ramirez‐Suarez J.C. , Xiong Y.L.
Published: July 2006

ABSTRACT: Transglutaminse (TGase)‐catalyzed interactions of whey (WPI)/myofibrillar (MPI) protein isolates were investigated under 5 conditions: (1) ionic strengths; (2) calcium/ethylenediaminetetra‐acetic acid (EDTA); (3) enzyme:substrate ratio; (4) WPI:MPI ratio; and (5) preheating of WPI (80 °C). TGase treatments of MPI in distilled water converted myosin heavy chain and actin into lower‐molecular‐weight polypeptides. The reaction, accelerated by the presence of WPI but diminished by NaCl, was completely reversed upon extended incubation. There was no visible WPI/MPI cross‐linking; and the enzyme:substrate or WPI:MPI ratio, preheating, calcium, and EDTA did not influence the enzyme reaction. TGase treatment did not alter the melting pattern of WPI/MPI mixtures, but markedly enhanced their thermal gelling ability.
Food Protein Functionality in a Liquid System: A Comparison of Deamidated Wheat Protein with Dairy and Soy Proteins
Authors: Webb M.F. , Naeem H.A. , Schmidt K.A.
Published: July 2006

ABSTRACT: Solubility, surface properties, overrun, foam stability, apparent viscosity, and emulsification properties were evaluated for 3% protein dispersions of deamidated wheat protein (DWP), sodium caseinate (SC), soy protein isolate (SPI), and whey protein isolate (WPI). DWP dispersion had the highest apparent viscosity, 25% higher emulsion activity index (EAI), and 82% higher emulsion stability index (ESI) when compared to SPI dispersions. Dispersions of DWP had similar foaming properties and surface properties when compared to SC, but had 50% higher EAI and 1000% greater ESI when compared to the 2 dairy proteins. The utilization of DWP could be expanded into liquid food systems currently using dairy proteins.
Characterization and Functional Properties of Soy β‐Conglycinin and Glycinin of Selected Genotypes
Authors: Khatib K.A. , Herald T.J. , Aramouni F.M. , MacRitchie F. , Schapaugh W.T.
Published: July 2006

ABSTRACT: The principal soy storage proteins, β‐conglycinin and glycinin, may provide valuable functionality as food ingredients. These soy protein fractions were isolated from K1430, Hutcheson, K93‐90‐29, and KS4997 and characterized for solubility, emulsion and surface properties, water holding capacity, and gel rheology. There were significant differences among genotypes regarding all functional properties. The K93‐90‐29 β‐conglycinin exhibited significantly better functional properties compared to the other genotypes except for foam stability. Regarding glycinin, Hutcheson exhibited significantly better functional properties compared to the other genotypes except for foam stability. Continuous evaluation of soy genotypes in various food systems coupled with genetic manipulation should continue to better assess the potential of soy proteins as food ingredients.
Heat‐induced Changes in Angel Food Cakes Containing Egg‐white Protein or Whey Protein Isolate
Authors: Pernell C.W. , Luck P.J. , AllenFoegeding E. , Daubert C.R.
Published: July 2006

ABSTRACT: Angel food cakes made from egg white or whey protein foams were compared. Cakes were evaluated based on final volume, dynamic volume change, and rheological transitions during baking. Cake expansion during baking was a function of protein concentration regardless of protein type. Cakes containing whey proteins had a lower ability to prevent collapse once starch gelatinization started during baking. Heat‐treating whey proteins or adding xanthan gum increases cake volume, but not to the extent of egg‐white proteins. Cakes containing egg‐white proteins became more elastic at 60 to 85 °C than those containing whey proteins, indicating physical differences in the heat‐set protein foam network associated with protein type.
Functional Properties of Seed Meals and Protein Concentrates From Tomato‐processing Waste
Authors: Sogi D.S. , Garg S.K. , Bawa A.S.
Published: July 2006

ABSTRACT: Functional properties of tomato seed meals (whole and de‐oiled) and protein concentrates (water, alkali, salt) were evaluated. Water and fat absorption of the meals were higher than the protein concentrates. The bulk density of the salt‐extracted protein concentrate was the highest. The pH values of the meals were neutral, whereas those of protein concentrates were in the acidic pH range. The foaming capacity and stability of meals and concentrates were poor but improved slightly with the addition of salt and sugar. The emulsion capacity of meals and concentrates was good, while the emulsion stability was excellent except for alkali‐extracted protein concentrate.
New Process for Texturizing Partially Dehydrated Biological Products Using Controlled Sudden Decompression to the Vacuum: Application on Potatoes
Authors: Louka N. , Allaf K.
Published: July 2006

ABSTRACT: A new texturizing process, Controlled Sudden Decompression (Détente Instantanée Contrôlée “DIC®“), has been developed to improve the quality of hot‐air dried food. The process involves a treatment under high pressure of steam followed by an extremely rapid decompression to the vacuum. Coupled with a drying step, this process provides high‐quality finished products for a similar overall cost to hot‐air drying alone. The definition, design, and achievement of the appropriate equipment have already been dealt with. In this study, 2 parameters directly related to DIC expansion were examined: initial pressure (before decompression) in the vacuum tank and the decompression duration. Impact of structural modifications on the rate of dehydration was also quantified.
Lipolysis of Butter Oil by an Immobilized Kid Goat Pregastric Esterase
Authors: Hill C.G. , Ghannouchi S. , Garcia H.S.
Published: July 2006

ABSTRACT: A kid goat pregastric esterase immobilized in a continuous flow, hollow‐fiber reactor was employed to hydrolyze anhydrous milkfat, producing lipolyzed butter oil. The effects of temperature and pH on the rate of lipolysis were monitored by titration of the effluent stream for total acidity. The overall rate of hydrolysis was fastest at 40 °C and pH 6.0. The reaction rate was modeled by an expression of the general Michaelis‐Menten form based on a ping pong bi bi mechanism. Nonlinear regression analyses indicated that the experimental data were consistent with the form of the ping pong bi bi mechanism that assumes that the rate‐controlling step is acylation of the enzyme.
A Lipoprotein‐derived Antimicrobial Factor from Hen‐egg Yolk is Active Against Streptococcus Species
Authors: Brady D. , Gaines S. , Fenelon L. , Mcpartlin J , O'Farrelly C.
Published: July 2006

ABSTRACT: Oral administration of hen‐egg yolk provides protection against specific pathogens. We examined the antibacterial activity of fractionated egg yolk against 2 pathogenic Streptococcus strains, using an in vitro assay. A water‐soluble protein fraction (WSPF) of egg yolk consistently inhibited the growth of S. mutans by 25%. The WSPF treated with pancreatin demonstrated > 80% inhibition of bacterial growth. Growth of S. sanguis was completely inhibited. Gel filtration and ion exchange chromatography established that anti‐Streptococcal activity resided with lipoproteins. Antibacterial activity was released by crude lipase or a combination of lipase and protease treatment of egg lipoproteins. Thus, hen‐egg yolk lipoproteins are important molecules for lipid‐mediated antimicrobial activity.
Use of Rectified Grape Juice in Yogurt Edulcoration
Authors: Calvo M.M. , Diez O. , Cobos A.
Published: July 2006

ABSTRACT: Plain yogurt was prepared by adding 5 or 10% rectified grape juice (RGJ) or 3% sucrose to concentrated milk. Influence of the sweeteners addition on fermentation, and on syneresis, rheological, and sensorial properties after 14 d of storage was analyzed. Addition of a 10% RGJ increased the fermentation and reduced the lactic acid production; however after 14 d of storage the pH and L‐lactic production were similar to the control. Syneresis was not affected by sweeteners addition. The storage modulus (G′) andloss modulus (G″) were slightly different from the control in samples added to a 5 or 10% RGJ. The panelists found that yogurt added to a 10% RGJ was significantly (P < 0.001) sweeter than the control and also significantly (P < 0.001) sweeter than those added to a 3% of sucrose.
Comparative Performance Analysis of Three Electronic Nose Systems Using Different Sensor Technologies in Odor Analysis of Retained Solvents on Printed Packaging
Authors: Van Deventer D. , Mallikarjunan P.
Published: July 2006

ABSTRACT: The food industry is interested in determining the applicability of using electronic nose instrumentation for odor analysis of retained solvents on packaging materials. Performance analyses of electronic nose systems using 3 leading sensor technologies showed that the conducting polymer sensor technology demonstrated the most discriminatory power, while all 3 were able to discriminate among film samples at various levels of retained solvents. All 3 systems correctly identified 100% of unknown samples. Based on discriminatory power and practical features, the FOX 3000 and the Cyranose 320 were superior. The results indicate that electronic nose instrumentation can be used as a complimentary discriminatory tool in quality control for packaging.
Physicochemical and Sensory Properties of Corn Tortillas Made from Nixtamalized Corn Flour Fortified with Spent Soymilk Residue (okara)
Authors: Waliszewski K.N. , Pardio V. , Carreon E.
Published: July 2006

ABSTRACT: The chemical study of okara composition and a sensory evaluation study were conducted to determine the effect of okara supplementation on certain physical, chemical and sensory properties of corn tortilla. Dried okara was added at the level of 5,10,15,20, and 25% to nixtamalized corn flour. Due to flavor, enriched tortillas at levels higher than 10% of okara were not accepted. At 10% of okara supplement, lysine and tryptophan content in tortilla were increased from 56 and 70% of FAO profile to 93 and 92% respectively.
Accelerated Cheddar Cheese Ripening with an Aminopeptidase Fraction from Squid Hepatopancreas
Authors: Raksakulthai R. , Rosenberg M. , Haard N.F.
Published: July 2006

ABSTRACT: An aminopeptidase (AP) fraction from squid (Illex illecebrosus) hepatopancreas was added to Cheddar cheese at 2 levels, and its influence on ripening indices was determined for up to 3‐mo storage at 11 °C. Two commercial enzymes (Neutrase ® and Flavourzyme ®) were similarly tested. Cheese with the higher level of squid AP contained more soluble N, amino acids, and Cheddar flavor after 1 mo, but it developed defects in texture and bitterness as ripening progressed. Cheese with less squid AP did not differ from the control with respect to all ripening indices over 3‐mo storage. Ripening Cheddar contains cysteine protease inhibitor(s) that inhibit low levels of squid AP but not Neutrase ® and Flavourzyme ®.
Walnut Free Radicals Studied by ESR
Authors: Szocs F.
Published: July 2006

ABSTRACT: The electron spin resonance (ESR) method was used. Walnut kernels were annealed within a wide temperature range [20 to 200 °C] in air and in vacuum. The concentration of free radicals increased with the temperature of sample annealing, especially between 120‐200 °C. Annealing in vacuum brought about a lower increase in free radical concentration than the annealing in air. A considerable increase in free radical concentration was observed during annealing of samples impregnated with dibenzoyl peroxide. The observed ESR spectrum is a nonresolved singlet exhibiting a line width of about 0.8 mT and a g‐factor of 2.0043. The increase in free radical concentration indicates degradation and oxidation processes.
Mechanisms of Interaction Between Vanillin and Milk Proteins in Model Systems
Authors: Chobpattana W. , Jeon I.J. , Smith J.S. , Loughin T.M.
Published: July 2006

ABSTRACT: The effects of milk proteins on vanillin intensity reduction were studied in a phosphate buffer (pH 6.5) using urea and sodium dodecyl sulfate (SDS) as bond disrupting agents. The reduction of vanillin occurred immediately as the protein was introduced to the system. Bovine serum albumin (BSA) interacted more with vanillin than sodium caseinate (CAS) did. Heat treatment had no effect on vanillin reduction of the CAS system; however, free vanillin content was higher in the heated than nonheated BSA system. Hydrogen bonding appeared to be a major force for the interaction of vanillin and CAS. However, hydrophobic interaction seemed to be more important than hydrogen bonding in the vanillin and BSA system.
Characterization of Lactoferrin (LF) from Colostral Whey Using Anti‐LF Antibody Immunoaffinity Chromatography
Authors: Tu Y.‐Y. , Chen C.‐C. , Chang J‐H. , Chang H‐M.
Published: July 2006

ABSTRACT: Lactoferrin (LF) in colostral whey was isolated by anti‐LF immunoglobulin in yolk (IgY)‐Sepharose 4B immunoaffinity chromatography, and parameters such as binding capacity (qm) and dissociation constant (Kd, × 10−6 M) of this immunoaffinity gel for LF were discussed. Purification folds for colostral whey I (from colostrum collected within 6 d of postpartum) and colostral whey II (from colostrum collected within 1 d of postpartum) by anti‐LF IgY‐immunoaffinity chromatography were 135.80 and 103.60, respectively. The recovery for LF in the same colostral whey sample by anti‐LF IgY‐immunoaffinity chromatography was 82 to 99 %. qm of anti‐LF IgY‐immunoaffinity gel for LF in colostral whey I and whey II were 0.372 and 0.272 mg LF/mL wet gel, respectively. Kd of anti‐LF IgY‐immunoaffinity gel for LF in colostral whey I was 1.594 × 10−6 M and II was 1.587 × 10−6 M.
Effects of Endpoint Temperature on the Internal Color of Pork Loin Chops of Different Quality
Authors: Lien R. , Hunt M.C. , Anderson S. , Kropf D.H. , Loughin T.M. , Dikeman M.E. , Velazco J.
Published: July 2006

ABSTRACT: The effects of 5 endpoint temperatures for cooked, internal color were determined for boneless pork longissimus muscle from 4 treatment groups: normal, normal‐injected, PSE, and DFD. Visual and instrumental color, myoglobin denaturation, and acid phosphatase (ACP) of raw and cooked samples were evaluated. Visual internal color became (P < 0.05) less pink as endpoint temperature increased; however, DFD chops were more pink (P < 0.05) and PSE chops were less pink (P < 0.05) than other treatments at most endpoint temperatures. Cooked color was similar (P > 0.05) for chops from normal and normal‐injected groups. Myoglobin denaturation increased as endpoint temperature increased. ACP activity in raw chops was not affected by treatment group and it was a good indicator of doneness at 71.1 °C.
Effects of Endpoint Temperature on the Internal Color of Pork Patties of Different Myoglobin Form, Initial Cooking State, and Quality
Authors: Lien R. , Hunt M.C. , Anderson S. , Kropf D.H. , Loughin T.M. , Dikeman M.E. , Velazco J.
Published: July 2006

ABSTRACT: :The effects of several parameters on the development of internal cooked color in ground pork were evaluated. Patties were made from normal or pale, soft, and exudative (PSE) pork and the pigment converted to either oxymyoglobin or deoxymyoglobin. Patties from these 4 treatment combinations were cooked from the frozen or thawed states to 5 endpoint temperatures. PSE patties and those containing oxymyoglobin exhibited premature browning as they appeared cooked and were more (P < 0.05) tan at lower temperatures than normal patties or those with deoxymyoglobin which had a slightly pink internal color at 71 °C. Percentage myoglobin denaturation increased as cooking temperatures increased (P < 0.05) for both types of meat and was greater in patties containing deoxymyoglobin than in those with oxymyoglobin. Patties cooked frozen had lower a* values (P < 0.05) than thawed patties at every endpoint temperature.
Physical, Thermal, and Barrier Characterization of Casein‐Wax‐Based Edible Films
Authors: Chick J. , Hernandez R.J.
Published: July 2006

ABSTRACT: Lactic acid casein‐wax‐based edible films were prepared to study the effect of carnauba and candelilla waxes. Water and oxygen permeability, thermal properties, and microstructure were determined as a function of relative humidity. Scanning electron microscopy showed a partial phase separation of wax and protein. Water permeability decreased as wax content increased and as relative humidity decreased from 70 to 50%. Despite containing wax, films overall showed low decrease in water permeability. However, films with candelilla wax had lower water permeability values than those with carnauba wax. Films were able to be heat‐sealed. There was no difference in oxygen permeability compared to films without wax.
Drying Kinetics and Time‐Temperature Distribution of Pregelatinized Bread
Authors: Roberts J.S. , Tong C.H. , Lund D.B.
Published: July 2006

ABSTRACT: The experimental method of measuring the effective moisture diffusivity of bread, the representative hygroscopic porous material, was investigated. Drying curves and temperature profiles were obtained from cylindrical bread samples (0.3 and 0.6 porosity, and 0.011 and 0.018 m dia) under convective hot air conditions (50 to 90 °C oven temperatures and 1 to 3 m/s air velocity). The normalized drying curves were linear, suggesting that Fick's diffusion equation was applicable in determining the diffusion coefficient, and the effective moisture diffusivities were in the range of reported values. Experimental determination of the temperature dependent diffusion coefficient requires isothermal conditions to exist in the material, but temperature gradients existed throughout drying of the bread samples. Thus, the linearity of normalized drying curves is not a guarantee that the moisture diffusivity is properly determined. The need to develop an apparatus to achieve isothermal conditions during experimental measurement of the effective moisture diffusivity is shown.
Protein Degradation by Lactobacillus plantarum and Lactobacillus casei in a Sausage Model System
Authors: Fadda S. , Oliver G. , Vignolo G.
Published: July 2006

ABSTRACT: :

The proteolytic activity of a starter culture involving Lactobacillus plantarum and Lactobacillus casei towards meat sarcoplasmic and myofibrillar proteins during the fermentation of a sausage‐like system was studied. After 96 h of incubation the proteolytic system of L. plantarum CRL681 caused a degradation of both sarcoplasmic and myofibrillar proteins, whereas L. casei CRL705 showed a different affinity to meat proteins. The inoculation of both strains showed a higher activity toward sarcoplasmic fraction. These results correlated with a high rate of sarcoplasmic protein degradation observed in SDS‐PAGE analysis. The generation of free amino acids as well as the pH drop at the end of the incubation period was maximal in presence of the mixed starter culture, thereby demonstrating the suitability of these strains to be used in the fermentation of meat products.
Response Surface Modeling for the Inactivation of Escherichia coli O157:H7 on Green Peppers (Capsicum annuum) by Ozone Gas Treatment
Authors: Han Y. , Floros J. D. , Linton R. H. , Nielsen S. S. , Nelson P. E.
Published: July 2006

ABSTRACT: :

The effects of ozone gas concentration (2 to 8 mg/l), relative humidity (RH) (60 to 90%), and treatment time (10 to 40 min) on inactivation of E. coli O157:H7 on green peppers were studied using response surface methodology. A 3‐factor Box‐Behnken experimental plan was designed and microbial log reduction was measured as a response. The statistical analysis of developed predictive model suggested that ozone gas concentration, RH, and treatment time all significantly (P < 0.01) increased the rate of log reduction of E. coli O157:H7. Among the 3 factors, the effect of ozone gas concentration on bacterial inactivation was the greatest, while the effect of RH was the least. The interaction between ozone gas concentration and RH exhibited a significant and synergistic effect (P < 0.05).
Effect of Iron on the Color of Barley and Other Cereal Porridges
Authors: Theuer R.
Published: July 2006

ABSTRACT: Iron added as ferrous sulfate at 500 mg*kg−1 to rice, oats, whole grain wheat, or proanthocyanidin‐free barley porridge caused significant changes in the Hunter “L”, “a”, and “b” values but the visual appearance of these porridges remained satisfactory. Porridge made with normal barley flour fortified with 500 mg*kg−1 of iron developed an unappealing gray color with ferrous sulfate, ferrous fumarate, or electrolytic iron, 3 salts differing in solubility. At 100 and 250 mg*kg−1 of iron, the discoloration of normal barley porridge was less pronounced, but still objectionable. When fortified with 50 mg*kg−1 of iron, normal barley porridge had a slight color change but was not noticeably gray. Thus barley‐containing foods can be fortified with a soluble iron compound at the level of iron used in enriched flour and similar cereal‐grain foods for the general population without developing an unattractive color.
β‐Galactosidase Activity and Cell Wall Breakdown in Apricots
Authors: Kovács E. , Németh‐Szerdahelyi E.
Published: July 2006

ABSTRACT: Apricots (Prunus armeniaca L., cultivars Magyar and Bergeron) were harvested 3 d apart (1st, 2nd and 3rd harvest). Fruits were stored at 4 to 6 °C, 90 % relative humidity, for 3 to 25 d. (β‐Galactosidase activity, pectin degradation, and softening were studied as a function of harvest and storage time. (β‐Galactosidase activity increased as a function of harvest; it increased continuously during storage in the case of cv. Bergeron. With Magyar enzyme activity reached a maximum value during storage in the case of 2nd and 3rd harvest fruits, then it declined. Total pectin and that solubilized neutral carbohydrate contents decreased as a function of storage. Solubilized pectin quantity did not depend either on harvest or on storage.
Physicochemical Properties of Pacific Whiting Surimi as Affected by Various Freezing and Storage Conditions
Authors: Reynolds J. , Park J.W. , Choi Y.J.
Published: July 2006

ABSTRACT: Effects of various freezing methods of surimi on the biochemical and physical properties, were examined. Stress values increased up to 3 mo and then decreased. Strain values significantly decreased over time, except freeze‐dried surimi stored at ‐18 °C. Yellowness (b*) of the freeze‐dried surimi stored at 22 °C increased significantly during storage. In addition, salt‐extractable proteins (SEP) decreased while dimethylamine (DMA) increased. Freeze‐dried surimi showed the highest SEP and the lowest DMA values after 9 mo storage. Electrophoretic patterns did not show any apparent damages to the MHC until 6 mo. At 6 and 9 mo, development of proteins with smaller molecular weights was observed, indicating proteolytic degradation during frozen storage.
Nonenzymatic Browning in Amorphous Food Models: Effects of Glass Transition and Water
Authors: Lievonen S.M. , Roos Y.H.
Published: July 2006

ABSTRACT: The effect of glass transition on nonenzymatic browning (NEB) rates of amorphous, L‐lysine, and D‐xylose containing maltodextrin (MD)‐ or polyvinylpyrrolidone (PVP)‐based food models, equilibrated into aw of 0.23, 0.33, or 0.44 was studied. Glass transition temperature, Tg, was measured using DSC and NEB rates, followed spectrophotometrically. Use of citrate buffer as a pH regulator was evaluated. The NEB rates were higher in PVP than in MD models. Arrhenius plots showed nonlinearity in the vicinity of the Tg. Increasing aw decreased Tg, but did not affect NEB rates around the Tg. The temperature difference (T ‐ Tg) was not a sufficient measure of material stability.
Effect of High Pressure and 4‐Hexylresorcinol on Enzymatic Activity and Darkening in Oysters
Authors: Pérez‐Mateos M. , López‐Caballero M.E. , Montero P.
Published: July 2006

ABSTRACT: Oysters treated with and without 4‐hexylresorcinol were pressurized (400 MPa/7 °C/10 min) and stored chilled for 21 d, either vacuum‐packed or packaged aerobically. The results of visual evaluation of darkening and polyphenoloxidase (PPO) activity levels suggest that during storage, non enzymatic browning occurred 1st, followed by blackening caused by PPO activity. PPO activity did not increase in the vacuum‐packed oysters during storage, but pressurization was observed to activate the PPO. Autolytic activity in the oysters increased due to the high‐pressure treatment, although higher autolysis levels were recorded in the unpressurized oysters at the end of storage. Inhibition of PPO activity by the 4‐hexylresorcinol was observed chiefly in the vacuum‐packed batches.
Disinfection and Solids Removal of Poultry Chiller Water by Electroflotation
Authors: Tsai L.‐S. , Hernlem B. , Huxsoll C.C.
Published: July 2006

ABSTRACT: In poultry processing, carcasses are chilled in water that is replenished at 1.9 L/bird. The high costs of water usage, wastewater treatment and refrigeration energy have raised the need for developing means for the safe reuse of processing water. An electroflotation device that concurrently disinfects and removes solids from overflow water was developed. At a charge of 280 C/L, electroflotation reduced aerobic bacteria and coliforms by 6 and 5 log CFU/mL, respectively, 1000‐fold more efficient than dosing with 150 mg/mL chlorine. Electroflotation removed 82% of the suspended solids and 14% of the soluble organic matter without the use of flocculant, indicating its potential for treating overflow water for reuse.
Properties of Wheat Dough at Sub‐Zero Temperatures and Freeze Tolerance of a Baker's Yeast (Saccharomyces cerevisiae)
Authors: Stecchini M.L. , Maltini E. , Venir E. , Del Torre M. , Prospero L.
Published: July 2006

ABSTRACT: This work studied the relationship between the freeze tolerance of a baker's yeast (Saccharomyces cerevisiae) and the physical properties of the frozen wheat dough. The behavior of wheat dough, of the gluten phase, and of the liquid phase at sub‐zero temperatures was examined by differential scanning calorimetry (DSC) and cryomicroscopy. The effect on yeast viability of dough water content, freezing and storage temperatures, and prefermentation before freezing was studied. Yeast viability was mostly affected by the freezing and storage temperatures, with temperatures below the glass transition temperature (Tg) giving the highest survival ratios. At temperatures above Tg, viability after freezing treatment and during storage seemed to be governed by different mechanisms, encompassing osmotic and mobility factors. Those factors were also found to influence the freeze tolerance of growing yeast in the presence of ethanol.
Modified Atmosphere Packaging of Cut Belgian Endives
Authors: Van de Velde M.D. , Van Loey A.M. , Hendrickx M.E.
Published: July 2006

ABSTRACT: Modified atmosphere packaging of cut Belgian endives was simulated based on experimentally determined package and product parameters. Permeability of commercial packaging films was determined at 3 temperatures. The film permeability ratio for CO2 and O2 varied between 1.6 and 6. Respiration rate of cut Belgian endives stored under 10%O2‐10%CO2‐80%N2 (optimal gas conditions) was measured at different temperatures. Initially, the activation energy for respiration rate was higher compared to the one for film permeability. After 3 d of storage, the Ea‐value for respiration rate was similar to the Ea‐value for film permeability. Simulations at constant temperature proved that none of the packaging films tested was suitable to maintain optimal gas conditions.
Bulgur Quality as Affected by Drying Methods
Authors: Hayta M.
Published: July 2006

ABSTRACT: Solar‐drying and microwave‐drying methods significantly affected the bulk density of bulgur samples in our study. The pilaf bulgur yield was highest for solar‐dried bulgur, followed by microwave‐, tray‐, and sun‐dried bulgur samples, respectively. The drying method affected protein extractability, bulgur yield, and water and oil absorption values of bulgur. The lightness (L) value was found significantly higher for solar‐, sun‐, and microwave‐dried pilav bulgur samples compared with tray‐dried bulgur. The redness (a) and yellowness (b) values of bulgur were also affected by drying methods. The drying method had no significant effect on flavor, mouthfeel, and appearance of bulgur samples.
Effect of Steam‐ and Hot‐Water Post‐Process Pasteurization on Microbial and Physical Property Measures of Fully Cooked Vacuum‐Packaged Chicken Breast Strips
Authors: Murphy R.Y. , Berrang M.E.
Published: July 2006

ABSTRACT: The microbial inactivation was conducted using fully cooked chicken breast strips that were surface‐inoculated with Listeria innocua (107 colony forming unit per gram product), vacuum packaged, and treated by steam or hot water at 88 °C for 10 to 35 min. The studies for physical properties were conducted using uninoculated products that were treated for 25 to 35 min. Both steam and hot water treatments were effective in inactivating L. innocua in the packaged products. No significant difference was found on the survivors of L. innocua between steam and hot water treatments. No significant difference was found on water activity and shear force among the treated and untreated products. However, significant difference was found on expressible and total moisture among treated and untreated products. This study showed that post process pasteurization with hot water or steam lowered microbial populations but affected the water purge from the products.
Hydration of Succinic Acid by Ultrasonication and its Effects on Taste
Authors: Murata Y. , Doe M. , Yano S. , Kataoka‐Shirasugi N.
Published: July 2006

ABSTRACT: We have investigated the possible changes in the hydration of succinic acid aqueous solution by weak ultrasonication based on 1H‐NMR measurements, and observed its effects regarding taste by sensory evaluation. The 1H‐NMR measurements showed that the peak area of the carboxyl proton was diminished in the succinic acid aqueous solution by ultrasonication and that the water proton was conversely enhanced. This means that weak ultrasonication slightly accelerated the hydration of succinic acid. The sensory evaluation showed that the succinic acid aqueous solution tasted weaker by ultrasonication (p < 0.05), though its concentration was unchanged. These results suggest that the slight change in the hydration state produces some changes in taste.
Spoilage of King Salmon (Oncorhynchus tshawytscha) Fillets Stored Under Different Atmospheres
Authors: Fletcher G.C. , Summers G. , Corrigan V. , Cumarasamy S. , Dufour J.P.
Published: July 2006

ABSTRACT: King salmon (Oncorhynchus tshawytscha) packaged in air (AIR), nitrogen (N2), or 40:60 carbon dioxide:nitrogen (CO2N2) was stored (0 °C) for 18, 25, and 54 d, respectively. Air packs (AIR9) were also stored at 9 °C for 4 d. A quality index (QI) method was developed to monitor sensory quality of cooked salmon. First detection of spoilage was 1.5, 15, 15, and 21 d for AIR9, AIR, N2, and CO2N2 treatments respectively. Total aerobic and sulfide‐producing bacteria, pH, drip loss, Eh, color, texture, ATP derivatives, trimethylamine, total volatile base nitrogen, thiobarbituric acid numbers, and peroxide values were determined. Only total aerobic counts and hypoxanthine were indicators of sensory deterioration across treatments and times.
The Effects of Water Extract of Polygonatum Odoratum (Mill) Druce on Insulin Resistance in 90% Pancreatectomized Rats
Authors: Choi S.B. , Park S.
Published: July 2006

ABSTRACT: After administration of 0.3 g Polygonatum Odoratum (Mill) Druce (POD) per 1 kg body weight for 2 mo with a 40% fat diet, serum glucose levels decreased with POD in 90% pancreatectomized (Px) and sham‐operated (Sham) rats, compared to placebo (P). Serum insulin concentrations were higher in Sham rats than Px rats. Additionally, compared to P, POD administration decreased serum insulin concentrations in Sham rats, but not in Px rats. Glucose disposal rates in peripheral tissues increased with POD in both Px and Sham rats. Glycogen deposits, GLUT4 contents, and fraction velocity of glycogen synthase in soleus muscle increased with POD administration in Px and Sham rats. In conclusion, POD ameliorates insulin resistance by enhancing glucose utilization in muscle.
Consumer Acceptability of Viscosity in Processed Tomato Products by African‐American, Latino, and Prototypical Consumer Groups
Authors: Claybon K.T. , Barringer S.A.
Published: July 2006

ABSTRACT: African‐American, Latino, and prototypical consumer viscosity preferences for ketchup, salsa, tomato sauce, pizza sauce, spaghetti sauce, and barbecue sauce are presented. A peak viscosity preference existed for all products: too thick or too thin was undesirable. Most, but not all, commercial products were in the acceptable range. Many were not in the most preferred viscosity range. The leading brand was within the most preferred viscosity range for all ethnic groups only for barbecue sauce and ketchup. Ethnicity had little influence on acceptance, but moderate influence on the most preferred viscosity. Latinos had the widest acceptance ranges. Understanding optimum viscosity ranges can help tomato processors increase quality for all consumers.
Effect of Lipid Extraction Process on Performance of Texturized Soy Flour Added Wheat Bread
Authors: Ryan K.J. , Homco‐Ryan C.L. , Jenson J. , Robbins K.L. , Prestat C. , Brewer M.S.
Published: July 2006

ABSTRACT:Wheat breads were prepared to contain 0%, 2%, 6%, or 12% non‐solvent extracted texturized soy flour (NSETSF) or solvent extracted texturized soy flour (SETSF) to evaluate their effects on instrumental and sensory characteristics. To compare the effects of added dough enhancers versus those contained in lip id‐extracted soy flour, a sucrose ester was included in some formulations. Both soy flours produced comparable loaves relative to percent inclusion. Texture analysis and trained sensory panel evaluation indicated that SETSF loaves were softer than NSETSF loaves. The consumer panel found bread with 12% NSETSF similar to the control. Texturized, lipid‐extracted soy flours added to wheat breads produced a “sucrose ester”‐like property.
Bioconversion of Egg Cholesterol to Pro‐vitamin D Sterols with Tetrahymena Thermophila
Authors: Valcarce G. , Nusblat A. , Florin‐Christensen J , Nudel B.C.
Published: July 2006

ABSTRACT: The potential use of the non‐pathogenic ciliate Tetrahymena thermophila for converting cholesterol into pro‐vitamin D sterols in egg suspensions was investigated. Conditions screened for efficient conversion included inoculum size and age, egg and egg yolk dilution, initial pH, and aeration. By optimizing these parameters, 55%± 6 cholesterol reduction was obtained in 24 hours incubation. Tetrahymena converted cholesterol into three unsaturated sterols, D7,22 bis‐dehydrocholesterol, an ergosterol analog (27%), D7‐dehydrocholesterol, also known as pro‐vitamin D3 (4%), and Δ22‐ dehydrocholesterol (8%). Despite significant proteolysis, culturing with Tetrahymena did not result in net consumption of total amino acids content, which was in fact increased by 16%± 2. These findings emphasize the potential use of Tetrahymena in the food industry.
TVB‐N Correlation with Odor Evaluation and Aerobic Plate Count in Mahi‐Mahi (Coryphaena hippurus)
Authors: Antoine F.R. , Wei C.I. , Otwell W.S. , Sims C.A. , Littell R.C. , Hogle A.D. , Marshall M.R.
Published: July 2006

ABSTRACT: Two groups of 6 mahi‐mahi fillets, one untreated and the other dipped in a suspension of Morganella morganii, were refrigerated at 7°C and sampled after 0, 2, 4, 6, 8, and 10 d of storage. Results were similar for both groups of fish. Total volatile base‐nitrogen (TVB‐N) reached 30 mg‐N/100 g on d 3, at which time aerobic plate count (APC) reached 106 colony forming units (CFU)/g and odor scores reached 6 on a scale of 1 to 10 (10 very fresh and 1 very spoiled). Good correlation existed between TVB‐N and odor intensity (r = 0.84), between TVB‐N and the log10 APC (r = 0.71), and between odor and the log10 APC (r = 0.91). These results show that TVB‐N can serve as a good indicator of chilled mahi‐mahi quality.
Changes in the Carbohydrate Fraction during Manufacture and Storage of Enteral Formulas
Authors: García‐Bantos J.L. , Olano A. , Corzo N.
Published: July 2006

ABSTRACT: Changes in the mono‐ and disaccharide fractions during manufacture and storage of enteral formulas were studied. Sterilization caused a considerable increase only in the maltulose content due to isomerization of maltose. Heat intensity and pH greatly influenced the formation of maltulose. Levels of maltulose up to 190 mg/100 mL were reached at pH 7.6 in samples heated at 120°C for 20 min. At the same pH value, the formation of maltulose during sterilization of samples increased with initial maltose content. Storage at 20°C did not cause changes in the maltulose content but an increase of maltulose was observed during storage at 30°C. The maltose/maltulose ratio appears to be a suitable indicator to assess the heat treatment during manufacture and to monitor product storage. Keywords: maltulose, processing, storage, enteral formulas
Blanching Effects on the Chemical Composition and the Cellular Distribution of Pectins in Carrots
Authors: Lo C.‐M. , Grün I.U. , Taylor T.A. , Kramer H. , Fernando L.N.
Published: July 2006

ABSTRACT: Carrots were blanched using 4 time‐temperature combinations. Galacturonic acid and sugar contents of pectin extracts were determined, and immunocytochemistry experiments elucidated changes in the cell membrane. Blanching decreased galacturonic acid and total sugar contents for all treatments. Carrots subjected to high‐temperature short‐time (HTST) blanching contained more total galacturonic acid and total sugars in pectins than carrots blanched for a long time at low temperatures (LTLT). Similar trends were observed for methylated pectin and neutral sugars. Immunocytochemistries showed separation of the 3‐way junction of cell walls, and LTLT‐blanched carrots showed higher levels of JIM 7‐labeled pectin (1.6 × 10−4 particles/nm2) than HTST‐treated carrots (5.9 × 10−5 particles/nm2).
A Rheological Study of Wheat Starch‐Water‐soluble Pentosan Mixtures Under Hydrothermal Gelling Conditions
Authors: Santos D.M.J. , Gama A.C. , Da Silva J.A. Lopes
Published: July 2006

ABSTRACT: Heterogeneous water‐soluble pentosans (WSP) were extracted from 2 different wheat flours. The dynamic rheological behavior of starch‐WSP mixtures was investigated to elucidate the effect of WSP on starch gelatinization and quenching the starch gels. In general, WSP had a detrimental effect on starch gelation. The decrease of water availability due to WSP may explain the observed higher onset temperature for starch gelatinization. However, the observed changes in rheological behavior during cooling and aging, and the more pronounced effects observed at excess water, suggest dependence on the WSP source and that WSP may have a more specific interacting effect with the amylose and/or amylopectin which prevents reorganization of both macromolecules within the starch network. Keywords: wheat starch, water‐soluble pentosans, dynamic rheological properties, gelatinization
Effect of Ultra‐high‐pressure Homogenization on Structure and on Rheological Properties of Soy Protein‐stabilized Emulsions
Authors: Floury J. , Desrumaux A. , Legrand J.
Published: July 2006

ABSTRACT: An ultra high‐pressure homogenizer (20 to 350 MPa) was used to realize fine food emulsions stabilized by soy proteins. The first aim of the work was to understand how dynamic high‐pressure processing affects soybean globulin conformation. Then, the effect of homogenizing pressure on the emulsions structure and rheology was investigated. High‐pressure homogenization caused denaturation of proteins due to strong mechanical forces and high temperatures encountered in the valve. Droplet sizes of emulsions were greatly reduced with high‐pressure homogenization and Newtonian liquid emulsions were converted into shear‐thinning emulsion gels by homogenization at pressures above 250 MPa. Hydrophobic interactions between proteins were supposed to cause the gel‐like network structure of emulsions.
Effect of Sucrose Esters and Sunflower Oil Addition on Crystalline Microstructure of a High‐melting Milk Fat Fraction
Authors: Martini S. , Puppo M.C. , Hartel R.W. , Herrera M.L.
Published: July 2006

ABSTRACT: The effects of sunflower oil (SFO) and the sucrose esters (SE) P‐1670, P‐170, and S‐170 on crystalline microstructure of a high‐melting milk fat fraction (HMF) was studied by polarized‐light microscopy (PLM) and confocal laser scanning microsopy (CLSM). The addition of SFO markedly diminished crystal size and delayed crystallization kinetics, as observed in PLM images. Addition of P‐1670 modified crystallization behavior only slightly. Addition of P‐170 and S‐170, however, markedly diminished crystal size and led to more transparent crystals, with lower amount of solids in each crystal. These results show that the microstructural properties of HMF were modifed by addition of SFO and by addition of SPE with low HLB.
Consumer Discrimination of Rancidity in Pork Loin Chops and Pork Sausages
Authors: Bryhni E.A. , Hunt M.C. , Ofstad R.
Published: July 2006

ABSTRACT: To determine if consumers could discriminate samples differing in rancidity, 2 experiments were conducted with freezer‐stored pork loin chops (M. longissimus dorsi) and sausages made from pigs fed diets varying in fatty acid composition. Samples were categorized as “normal” and “rancid” using Principal Component Analysis of data from trained sensory panel evaluations. These samples were presented to 2 consumer panels (n = 206 and n = 213). Rancidity did influence consumer preference. Consumers were able to discriminate between “normal” and “rancid” sausage, and preferred “normal.” No differences (P > 0.05) in preference or flavor were detected between the chop groups.
Influence of Chemical Characteristics of Beef Inside and Outside Semimembranosus on Color Traits
Authors: Sammel L.M. , Hunt M.C. , Kropf D.H. , Hachmeister K.A. , Kastner C.L. , Johnson D.E.
Published: July 2006

The influence of prerigor temperature and pH on muscle chemistry of the inside semimembranosus (ISM) and outside semimembranosus (OSM) in relation to initial color and color uniformity and stability was investigated. Cold‐boned ISM had a slower (p < 0.05) chill rate; faster (p < 0.05) pH decline; higher (p < 0.05) transmission values; and less (p < 0.05) metmyoglobin reducing ability, oxygen consumption, water holding capacity and color stability than the OSM. Cold‐boned steaks were 2‐toned in color and visually unacceptable at d 3 of display. Hot‐boned ISM and OSM chilled at the same rate and had similar pH declines, similar chemical characteristics and uniform stable color for 5 d of display. Chilling beef ISM faster should produce uniform stable color.