bluuebunny/crossref_metadata_2025 huggingface dataset:
Amylolytic Cultures of Lactobacillus acidophilus : Potential Probiotics to Improve Dietary Starch Utilization
Authors: Lee HS , Gilliland SE , Carter S
Published: July 2006

ABSTRACT: The amylase activity of twenty strains of Lactobacillus species isolated from intestinal contents of pigs was studied in vitro. Hydrolysis of starch was measured by following the disappearance of starch in a broth medium during the growth of all three strains. The amount of enzyme activity varied among strains. Three strains (A‐4, L9 and L23) were selected for further study based on their high amylolytic activity in a broth containing soluble starch as the only carbohydrate source. Strains A‐4 and L23 were identified as L. acidophilus and strain L9 was identified as L. fermentum. Among the three cultures, L. acidophilus L23 was selected as a potential candidate for use as a probiotic for improving digestion of starch in pigs based on its growth and hydrolysis of raw starch. The enzyme activity of L. acidophilus L23 was associated with the cell envelope and that of L. fermentum L9 was extracellular. The enzyme activity of L. acidophilus A4 was found in both locations. The enzyme activity of L. acidophilus L23 was inducible rather than constitutive.
Sensory Descriptive Analysis of Soymilk
Authors: Torres‐Penaranda A.V. , Reitmeier C.A.
Published: July 2006

ABSTRACT: A descriptive analysis panel developed terms to describe aroma and flavor of soymilk. Panelists evaluated a commercial soymilk and soymilks processed with beans from the normal or lipoxygenase‐free lines. Descriptors used to describe “beaniness” were “raw as hexanal” for flavor or aroma, “grassy” flavor, and “sweet as green floral” flavor. High correlations were found among these attributes. Judges were consistent in the use of terminology. “Beaniness” for the normal soymilk was described by the terms “raw aroma as in hexanal” and “raw flavor as in hexanal,” while “beaniness” for soymilk from the lipoxygenase‐free line was described by the terms “sweet as green floral” and “grassy” flavors.
Nutrigenomics: Application of Genomics Technologies in Nutritional Sciences and Food Technology
Authors: Van Der Werf M.J. , Schuren F.H.J. , Bijlsma S. , Tas A.C. , Ommen B. Van
Published: July 2006

ABSTRACT: The holistic study of the keystone biomolecules by applied genomics is one of the intellectual products of the current molecular biology revolution. These applied genomics technologies (transcriptomics, proteomics, and metabolomics) aim at analyzing the components of a cell in its entirety and have, together with the developments in computing, ushered in a new era in scientific methodology for the life sciences. Genomics technologies have mainly been set up and further developed by the pharmaceutical industry, but will also be invaluable to the food industry. Only recently, the first papers about nutrigenomics and the application of genomics in nutrition science and food technology have appeared. In this review, we briefly explain the essence of the various applied genomics technologies, and focus on the impact that these technologies will have in the food industry.
Volatile Flavor Compounds of Sweetened Condensed Milk
Authors: Shimoda M. , Yoshimura Y. , Yoshimura T. , Noda K. , Osajima Y.
Published: July 2006

ABSTRACT: The volatile compounds of sweetened condensed milk (SCM) were investigated to explain their contribution to SCM flavor. Commercially processed SCM was diluted with water and the volatiles were isolated by simultaneous steam distillation‐extraction under reduced pressure. Commercial liquid milk was used for comparison. The odor concentrate was analyzed by GC and GC‐MS, and then fractionated by silica gel TLC and preparative GC to determine the contributors to SCM flavor. Major volatile compounds were 10 fatty acids, 14 lactones, 10 ketones, 13 hydrocarbons, 8 alcohols, 4 aldehydes, and 8 miscellaneous compounds. δ‐Decalactone and δ‐dodecalactone were the principal contributors to SCM flavor although the other lactones may contribute as well.
De‐esterification and Transacylation Reactions of Pectinesterase from Jelly Fig (Ficus awkeotsang Makino) Achenes
Authors: Jiang C.‐M. , Lai Y.‐J. , Lee B.‐H. , Chang W.‐H. , Chang H.‐M.
Published: July 2006

ABSTRACT: Pectinesterase (PE) was isolated from jelly fig (Ficus awkeotsang Makino) achenes, then the optimal conditions for de‐esterification and transacylation reactions were determined. Molecular weight of pectin (DE = 62.8 %) when reacted with PE at pH 6.5 and 45 °C in 0.2 M NaCl for 20 min remarkably increased from the original 72 kDa to 410 kDa, as determined by Fractogel TSK 65(S) gel permeation chromatography. Prolonging the incubation time of pectin‐PE mixtures to 2 and 4 h also increased the molecular weights of pectin. Therefore, transacylation reaction was considered to occur and to increase the molecular weight of pectins when de‐esterification reaction was catalyzed by pectinesterase (PE).
Interactions of κ‐carrageenan Plus Other Hydrocolloids in Fish Myosystem Gels
Authors: Pérez‐Mateos M. , Hurtado J.L. , Montero P. , Fernández‐Martín F.
Published: July 2006

ABSTRACT: Mixtures of κ‐carrageenan plus other hydrocolloids (locust bean, guar, xanthan, iota‐carrageenan, sodium carboxymethylcellulose, and sodium alginate) were examined for their effects on the mechanical and water holding properties of heat‐induced gels made from washed blue whiting mince. Gel structure and thermal behavior were also studied. No synergistic effect was detectable through functional properties except for the mixture of κ‐carrageenan with locust bean gum. Light microscopy revealed that κ‐carrageenan and xanthan mixed locally with locust bean at its rich domains. κ‐carrageenan and xanthan presented interactions with the protein matrix, which were more discernible in the first case. Differential scanning calorimetry (DSC) revealed faint interactions for the mixtures of κ‐carrageenan with locust bean and with xanthan, and weakly synergistic gelling effects between the last two hydrocolloids. The blend of κ‐carrageenan with sodium alginate exhibited thermally strong synergistic interactions but no particular effects were induced on corresponding functional properties.
Mealiness in Apples: Towards a Multilingual Consumer Vocabulary
Authors: Andani Z. , Jaeger S.R. , Wakeling I. , MacFie H.J.H.
Published: July 2006

ABSTRACT: Three commercial varieties of dessert apples known to be susceptible to varying degrees of mealiness were evaluated by descriptive sensory profiling. In parallel, consumer testing using the repertory grid technique was conducted with consumers representing 5 different European countries. Generalized Procrustes Analysis of the repertory grid data suggested a cross‐cultural consensus with respect to consumer perception of mealiness. In particular, mealiness was associated with the texture of Cox apples. Curved box‐plots, an innovative extension of ordinary box‐plots, was used to explore the consumers’use of descriptive attributes. This indicated that although consumers perceived mealiness similarly, they described their perceptions differently.
Pork Quality is Affected by Early Postmortem Phosphate and Bicarbonate Injection
Authors: Wynveen E.J. , Bowker B.C. , Grant A.L. , Lamkey J.W. , Fennewald K.J. , Henson L. , Gerrard D.E.
Published: July 2006

ABSTRACT: The ability of sodium polyphosphate (P) to alter postmortem pH declines and pork quality was investigated. Hams from electrically stimulated carcasses were injected 18 min postmortem with P or sodium bicarbonate (SB). P and SB reduced (P 0.001) pH decline and improved (P < 0.05) color. P and SB administration improved water‐holding capacity as indicated by reductions (P 0.05) in drip loss, thaw loss, and cooking loss values. P and SB also reduced (P 0.001) shear values. These data showed delivery of P and SB was effective in altering postmortem pH declines and improving the quality of pork.
Storage and Cultivar Effects on Shear Compression Values and Esterified Cell Wall Phenolics in Carrots
Authors: Beveridge T. , Harrison J.E.
Published: July 2006

ABSTRACT: Phenolics esterified to cell walls in carrots were found to consist primarily of p‐hydroxybenzoic acid with minor contributions from ferulic and vanillic acids and vanillin. These compounds could be indexed by standardized measurement of absorbance at 254 nm. As indexed, esterified cell wall phenolics varied widely between carrot cultivars and increased with carrot storage. These increases were not correlated with increased carrot toughness as determined by measurements in a shear compression cell. Carrot texture was unaffected by the levels of esterified cell wall phenolics present in the tissue.
Effects of Ascorbic Acid on Peroxidase and Polyphenoloxidase Activities in Fresh‐Cut Cantaloupe Melon
Authors: And O. Lamikanra , Watson M.A.
Published: July 2006

ABSTRACT: Peroxidase (POD) and polyphenol oxidase (PPO) in minimally processed cantaloupe melon (Cucumis melo L. var. reticulatus Naud) were assayed and the effect of ascorbic acid on their respective activities during storage at 4 °C was determined. POD activity decreased with storage and was inhibited by ascorbate treatment. Two native electrophoretic POD bands with estimated molecular weights 240 and 170 kDa respectively were obtained. Isoelectric focusing separated six acidic POD isozymes with isoelectric points between 5.1 and 6.0, possibly subunits of the POD isozymes. PPO activity in the cantaloupe melon extract was very weak and the fruit's content of oxidizable phenolic compounds was negligible.
Differences in Gelation Characteristics of Natural Actomyosin from Two Species of Bigeye Snapper, Priacanthus tayenus and Priacanthus macracanthus
Authors: Benjakul S. , Visessanguan W. , Ishizaki S. , Tanaka M.
Published: July 2006

ABSTRACT: Natural actomyosin (NAM) of P. tayenus exhibited higher turbidity and storage modulus (G′) upon heating, compared to that of P. macracanthus, suggesting the higher protein aggregation and rigidity. At temperature above 35 °C, P. tayenus NAM had higher surface hydrophobicity and disulfide bond formation than P. macracanthus NAM. The α‐helix content of NAM from both fish species decreased as the temperature increased, indicating changes in structural conformation during heating. NAM gel from P. tayenus rendered more three‐dimensional network than that from P. macracanthus. These results indicated that P. tayenus NAM possessed superior gelling characteristic to P. macracanthus NAM due to the higher aggregation of protein caused by both hydrophobic interaction and disulfide bond.
Chemical Modification of Pigskin Gelatin: Factors Affecting the Esterification of Gelatin with Fatty Acid
Authors: Djagny K.B. , Wang Z. , Xu S.
Published: July 2006

ABSTRACT: This study investigated the esterification of pigskin gelatin with fatty acid catalyzed by acid in aqueous medium. Factors affecting the esterification reaction B temperature, pH, water content, fatty acid concentration, fatty acid type and reaction time‐ were elucidated in the view of optimizing the reaction. Under the same experimental conditions, increase in fatty acid concentration permitted the determination of the maximum amount of fatty acid that could be esterified per unit weight of gelatin and demonstrated that not all the hydroxyl functional groups present in the gelatin could be blocked by the fatty acid chains.
Mass Balances in Porous Foods Impregnation
Authors: Roa V. , Tapia M.S. , Millán F.
Published: July 2006

ABSTRACT: A simple model based on mass balance equations is proposed for prediction of the final mass and composition of products subjected to vacuum impregnation. It was applied to some tropical fruits in a fruit‐sucrose solution system. The phenomenon can be described in terms of volumetric fraction of impregnating solution as the basic modeling parameter, instead of effective porosity. To use the equations of the model, only routine laboratory equipment and simple experiments are required. Prediction of the final weight of impregnated fruit was accomplished with an average absolute error of 2 to 3%, while in final composition of the fruit (total solids), it was 5.7 %.
Keeping Quality of Sea‐Frozen Thawed Cod Fillets on Ice
Authors: And E. Martinsdóttir , Magnússon H.
Published: July 2006

The objective was to evaluate the suitability of sea‐frozen, thawed cod fillets for the “chilled” seafood market. Fillets were kept frozen for 17 mo. After thawing, fillets were kept iced and at 4°C. Microbiological research on fillets showed higher initial numbers in post‐rigor than pre‐rigor fillets. Pre‐rigor fillets were judged fresher after 2 mo of storage compared to post‐rigor. With longer freezer storage, lower initial freshness scores were obtained, and formation of trimethylamine in thawed fillets was slowed. Thawed fillets frozen prior to rigor merited higher scores for freshness than fillets frozen post‐rigor. This difference decreased with prolonged freezer storage. The results strongly indicate that fillets should be frozen pre‐rigor.
Concise Reviews and Hypotheses in Food Science
Authors: Lund Daryl B.
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
Investigation of Cornmeal Components Using Dynamic Vapor Sorption and Differential Scanning Calorimetry
Authors: Teoh H.M. , Schmidt S.J. , Day G.A. , Faller J.F.
Published: July 2006

Degermed cornmeal, native starch, and corn gluten meal were individually extruded. DVS technology was used to produce isotherms and to condition extrudates to a constant moisture for Tg analysis. The DVS method results are compared to a PEC method. DSC was used to determine Tg. Isotherm and Tg data for starch and corn gluten meal were used to predict cornmeal snack sorption and Tg behavior.

The Tg for extruded cornmeal, dent starch, and corn gluten meal at 18.5%db moisture content were 46.2, 49.4, and 12.7 °C, respectively. This suggests that the polymeric fractions of cornmeal (starch, protein) contribute to the Tg of cornmeal approximately based on the weight fraction of each polymer.
Creaming Stability of Oil‐in‐Water Emulsions Formed with Sodium and Calcium Caseinates
Authors: Srinivasan M. , Singh H. , Munro P.A.
Published: July 2006

Creaming stability of emulsions formed with calcium caseinate, determined after storage of emulsions at 20 °C for 24 h, increased gradually with an increase in protein concentration from 0.5% to 2.0%; further increases in caseinate concentration had much less effect. In contrast, the creaming stability of sodium caseinate emulsions showed a decreased with an increase in protein concentration from 0.5% to 3.0%. Confocal laser micrographs of emulsions formed with >2% sodium caseinate showed extensive flocculation of oil droplets with the appearance of a network structure. However, emulsions formed with calcium caseinate or emulsions formed with low concentrations of sodium caseinate (0.5% and 1.0%) were homogenous with no sign of flocculation.
Prevention of Potato Spoilage During Storage by Chlorine Dioxide
Authors: Tsai L.‐S. , Huxsoll C.C. , Robertson G.
Published: July 2006

ABSTRACT: Acidified Oxine (AO) is a mixture of chlorite and chlorine dioxide. At 7.8 ppm available chlorine dioxide (ACD) for 10 min, it reduced 7.4 log CFU/mL of Erwinia carotovora, a potato pathogen, in phosphate buffer. Exposing potatoes to air purged through AO solutions proportionally reduced inoculated E. carotovora. A 40% reduction of spoilage was achieved by exposing to AO of 100 ppm ACD under an accelerated test. AO was demonstrated to be potentially effective in preventing potato spoilage without any significant risks of chemical residual or change of skin color.
Thermal and High‐Pressure Inactivation of Tomato Polygalacturonase: A Kinetic Study
Authors: Fachin D. , Loey A. Van , VanLoeyIndrawati A. , Ludikhuyze L. , Hendrickx M.
Published: July 2006

ABSTRACT: Polygalacturonase (PG) was extracted from tomato fruit. The inactivation kinetics of the PG crude extract was investigated under isothermal and isobaric‐isothermal conditions. Thermal inactivation of tomato PG in the temperature range 58 to 65 °C could be described by a fractional conversion model, and in the temperature range from 70 to 90 °C by a biphasic model. Pressure‐temperature inactivation (range 300 to 600 MPa/5 to 50 °C) of tomato PG could be described by a fractional conversion model, which points to first‐order inactivation kinetics of a pressure‐sensitive enzyme fraction and to the occurrence of a pressure‐stable PG fraction. A mathematical model describing the influence of pressure and temperature on the inactivation rate constant was formulated.
New HPLC Method to Determine Ethyl Carbamate in Alcoholic Beverages Using Fluorescence Detection
Authors: Herbert P. , Santos L. , Bastos M. , Barros P. , Alves A.
Published: July 2006

ABSTRACT: A new methodology to the quantification of ethyl carbamate (EC) has been developed. This method allows the analysis by HPLC of ethyl carbamate in samples of wine, fortified wine, and wine brandy, by a pre‐column derivatization with 9‐xanthydrol, and fluorescence detection. This does not require previous sample extraction or concentration. The method presents an average recovery of 96% among samples studied, a detection limit of 4.2μg/L, and an average intermediate precision of 6.3%. The comparison of the results obtained for EC analysis on the same wine brandy samples by GC/MS and HPLC are statistically indistinguishable with 97.5% probability. The results of the analysis of 42 samples are presented.
Desulfiting Dried Apricots by Hydrogen Peroxide
Authors: Ozkan M. , Cemeroglu B.
Published: July 2006

ABSTRACT: Removal of sulfites from excessively sulfited dried apricots using hydrogen peroxide (H2O2) was studied. Dried apricots were dipped into 0.5, 1.0, and 1.5% H2O2 solutions at 20 °C and 40 °C for various times. At 60 °C, apricots were also treated with 1% H2O2 solution. Removal of sulfites by H2O2 followed a 1st‐order kinetic model. At 20 °C to 60 °C and 1% H2O2 concentration, the Ea value was 22.46 kJ mol−1. H2O2 treatment caused lighter, more yellow, and less red dried apricots. Critical factors for H2O2 application are choosing the appropriate H2O2 concentration, temperature, and exposure time and without bleaching the natural color of dried apricots.
Identification of Cephalopod Species (Ommastrephidae and Loliginidae) in Seafood Products by Forensically Informative Nucleotide Sequencing (FINS)
Authors: Chapela M.J. , Sotelo C.G. , Calo‐Mata P. , Pérez‐Martín R.I. , Rehbein H. , Hold G.L. , Quinteiro J. , Rey‐Méndez M. , Rosa C. , Santos A.T.
Published: July 2006

ABSTRACT: An identification technique of commercially important cephalopods based on 16s RNA analysis was developed. A set of primers was designed to amplify a fragment of approximately 200 bp that presents enough variability for reliable species identification. Sequences from this fragment of 9 different authentic species were studied, genetic distances were measured, and a phylogenetic tree was constructed, with individuals of the same species grouped within the same cluster. Eight different types of commercial seafood products, mainly labelled as “squid rings”, were analyzed and sequences were employed for species identification showing that FINS is a suitable technique for identification of processed cephalopods.
Color, Oxidation‐Reduction Potential, and Gas Production of Irradiated Meats from Different Animal Species
Authors: Kim Y.H. , Nam K.C. , Ahn D.U.
Published: July 2006

ABSTRACT: Turkey breasts, pork loins, and beef loins were aerobically or vacuum‐packaged and electron beamirradiated at 3 kGy. Irradiation increased the redness of turkey breast regardless of packaging or storage. Irradiation drastically decreased the redness of aerobically packaged beef loin. Irradiated meats produced higher amounts of CO and CH4 than nonirradiated. The oxidation‐reduction potential (ORP) of meats decreased after irradiation, but increased during the storage. Little differences in CO and ORP values among the irradiated meats from different species were detected. This indicated that CO and ORP were not the only factors involved in the color changes of beef loin by irradiation.
Physicochemical Properties and Starch Granular Characteristics of Flour from Various Manihot Esculenta (Cassava) Genotypes
Authors: Niba L.L. , Bokanga M.M. , Jackson F.L. , Schlimme D.S. , Li B.W.
Published: July 2006

ABSTRACT: Flour and starch were produced from 11 cassava genotypes. Starch and total dietary fiber contents were determined using a single‐enzyme gravimetric procedure and high‐performance anion exchange chromatography, pasting profiles by rotary viscometry, water holding capacity gravimetrically, and granular characteristics by scanning electron microscopy. Starch and total dietary fiber contents varied among genotypes. Flour peak viscosities, setback, and final viscosities differed significantly. Flour water holding capacity correlated with flour peak viscosity (r = 0.7). Starch granules ranged from 9 to 20 μm. Predominant granule shapes were oval, rounded, and truncated. The results provide insights into cassava genotype characteristics, and functionality of cassava starch and flour.
Textural Property of 6 Legume Curds in Relation to their Protein Constituents
Authors: Cai R. , McCurdy A. , Baik B.‐K.
Published: July 2006

ABSTRACT: We determined the relationship between textural property of legume curds and constituents of their proteins. The hardness, springiness, and cohesiveness of curds prepared from soybeans, chickpeas, and fava beans were 6.0 to 9.4 N, 0.93 to 0.95, and 0.67 to 0.77, respectively, higher than those of curds made from smooth peas, mung beans, and lentils, which were 4.2 to 4.9 N, 0.92, and 0.57 to 0.59, respectively. Soybeans, chickpeas, and fava beans had a higher proportion of 11S globulin and a lower proportion of 7S globulin than lentils, smooth peas, and mung beans. Soybeans, chickpeas, and fava beans produced a better texture of curd than did lentils, smooth peas, and mung beans, due to a higher proportion of 11S proteins.
Total Heme and Non‐heme Iron in Raw and Cooked Meats
Authors: Lombardi‐Boccia G. , Martinez‐Dominguez B. , Aguzzi A.
Published: July 2006

ABSTRACT: This study provides data on the total heme and non‐heme iron contents in poultry (chicken, turkey), beef, veal, lamb, horse, ostrich, rabbit, and pork meat cuts. The effect of cooking on heme iron content was also studied. Total iron and heme iron contents markedly differed between muscles in poultry. Heme iron in red meats ranged from 72 to 87%. Heme iron in rabbit and pork was 56 and 62% of total iron. Heating decreased heme iron, the severity of the losses depended on cooking methods: in poultry, losses ranged from 22 to 43%; less severe impact was detected in pan‐cooked meat, where the losses ranged from 1 to 24%.
Hydrolysis of Caseins By Extracts of Cynara Cardunculus Precipitated by Ammonium Sulfate
Authors: Silva S.V. , Barros R.M. , Malcata F.X.
Published: July 2006

ABSTRACT: Polyacrylamide gel electrophoresis (in the presence of urea) and gel permeation chromatography were employed to assess the profile of hydrolysis of caseins and the activity of enzymes contributed by the flowers of the plant Cynara cardunculus on bovine caseins, after previous precipitation with ammonium sulfate or in a plain crude aqueous extract. Results indicated that the qualitative degradation profile of bovine caseins by plant enzymes (cardosins) remains essentially unchanged upon extraction, and quantitative analysis showed that the precipitated fractions had a higher coagulant‐to‐proteolytic activity ratio; hence, the results showed that inexpensive precipitation with ammonium sulfate can successfully be used as a purification method in the production of that plant coagulant in standardized form.
Continuous Production of Oligodextrans via Controlled Hydrolysis of Dextran in an Enzyme Membrane Reactor
Authors: Mountzouris K.C. , Gilmour S.G. , Rastall R.A.
Published: July 2006

ABSTRACT: The continuous production of oligodextrans was investigated via the enzymatic hydrolysis of industrial grade dextran using an endodextranase. A recycle continuous stirred tank (CSTR) membrane reactor system was employed to provide the means of controlling oligodextran physicochemical characteristics. Response surface methodology (RSM) and a central composite statistical experimental design were used to assess the effects of substrate concentration (20 to 50 g dm3), enzyme concentration (6250 to 62500 U dm3), and residence time (60 to 120 min) in the reactor on the yield, dextrose equivalent (DE), and oligosaccharide content of the products. The reactor system was operated at steady state, generally obtained within 60 to 120 min from reactor start‐up. Oligodextran yields ranged from 84.4% to 98.7%, DE values ranged from 22 to 41, and oligosaccharide content ranged from 55.9% to 93.4 % (w w−1). The reactor produced 3 types of oligodextran products, with respect to their polysaccharide content: (a) <: 15%, (b) 15% to 30%, and (c)> 30% and < 44%. Oligodextran molecular weight distributions were mainly within the molecular weight cut‐off (MWCO) of 10 kDa of the membrane used.
Using Salt and Microbial Transglutaminase as Binding Agents in Restructured Fish Products Resembling Hams
Authors: Ramírez J. , Uresti R. , Téllez S. , Vázquez M.
Published: July 2006

ABSTRACT: Restructured products were obtained from fish paste of silver carp (Hypophthalmichthys molitrix) by massaging and cooking in ham presses. Assayed were 3 levels of salt (0 as control, 1, or 2%) and 3 levels of microbial transglutaminase (MTGase). Changes on solubility of pastes, mechanical properties, WHC, and SDS‐PAGE of the cooked product were evaluated. MTGase needed the addition of NaCl to improve the mechanical properties of these restructured products. Better textural properties were obtained with 2% NaCl. Adding 0.3% of MTGase and 1% NaCl obtained a low‐salt, homogenous restructured meat block with 2773 g hardness, 29106 g/cm gel strength, 0.233 cohesiveness, and 11.6% extracted water.
Application of a Depth Sensing Indentation Hardness Test to Evaluate the Mechanical Properties of Food Materials
Authors: ÖZkan N. , Xin H. , Chen X.D.
Published: July 2006

ABSTRACT: A depth sensing indentation hardness test with an associated analysis is described as a convenient and simple technique for characterizing mechanical properties of food materials, such as hardness (H), elastic modulus (E), and an elasticity index (IE), which represents the ratio of elastic to total deformation. Storage modulus (G′) and loss tangent (tan§) of the selected model food material, a whey protein concentrate (WPC) gel, have also been determined using an oscillatory dynamic testing. Fractal dimension (D) and strain rate (or frequency) exponent (n) of the WPC gels were determined using both the indentation and dynamic test results. A good correlation between the results from the indentation and the dynamic tests was established. The effects of protein concentration, deformation rate, and chemical treatment on the mechanical properties of the WPC gels were clearly illustrated using the indentation test.
Visible/Near‐Infrared Spectroscopy: A New Tool for the Evaluation of Fish Freshness?
Authors: Nilsen H. , Esaiassen M. , Heia K. , Sigernes F.
Published: July 2006

ABSTRACT: The freshness as storage time in ice of cod (Gadus morhua) and salmon (Salmo salar) was estimated by visible/near infrared (VIS/NIR) spectroscopy. The correlation between spectral data and storage time was modeled by multivariate statistics. For cod, the best‐fit model was found by using the visible wavelength range, giving correlation of prediction of 0.97 with an error value of 1.04 d. For salmon, the best‐fit model was made with data from the NIR range giving correlation of prediction of 0.98 and an error value of 1.20 d. Hence, VIS/NIR spectroscopy proved useful for the evaluation of fish freshness.
Demonstration of Indicator Microorganisms on Surface of Vegetables on the Market in the United States and Mexico
Authors: Hirotani H. , Naranjo J. , Moroyoqui P.G. , Gerba C.P.
Published: July 2006

ABSTRACT: Presence of indicator microorganisms of fecal pollution on the surface of vegetables sold in retail markets is demonstrated. Vegetables were obtained from local markets in the U.S.A. and Mexico. At least 1 of the indicators, among coliphages, fecal streptococci, total coliforms, and fecal coliforms, was detected in every sample tested. Relatively small amounts of indicators were recovered from the U.S.A. samples. Fecal streptococci showed significant correlations with all other indicators. However, some U.S.A. samples low in fecal streptococci were found to harbor certain levels of other indicators. Upon introduction of an indicator system to detect the fecal contamination of agriculture crops, it is recommended that multiple indicator microorganisms be measured.
Effects of Pre‐ and Postharvest Chitosan Treatments to Control Storage Grey Mold of Table Grapes
Authors: Romanazzi G. , Nigro F. , Ippolito A. , DiVenere D. , Salerno M.
Published: July 2006

ABSTRACT: The effectiveness of pre‐ and postharvest treatments with chitosan (0.1, 0.5, and 1.0%) to control Botrytis cinerea on table grapes was investigated. In postharvest treatments, small bunches dipped in chitosan solutions and inoculated with the pathogen showed a reduction of incidence, severity, and nesting of grey mold, in comparison with the control. Single berries artificially wounded, treated with the polymer, and inoculated with B. cinerea showed a reduced percentage of infected berries and lesion dia. Higher chitosan concentrations demonstrated greater decay reduction. All preharvest treatments significantly reduced the incidence of grey mold, as compared to the control. Table grapes treated with 1.0% chitosan showed a significant increase of phenylalanine ammonia‐lyase (PAL) activity. Consequently, besides a direct activity against B. cinerea, chitosan produces other effects contributing to reduce decay.
Maturity Acceleration of Italian Dried Sausage by Staphylococcus carnosus—Relationship Between Maturity and Flavor Compounds
Authors: Stahnke L.H. , Holck A. , Jensen A. , Nilsen A. , Zanardi E.
Published: July 2006

ABSTRACT: The mature flavor of Salame Milano, an Italian dried sausage, was increased in two ways: by increasing maturation time or with a strain of Staphylococcus carnosus. The sensory and volatile profiles of the sausages were determined and the data analyzed by analysis of variance and chemometrics. Sausages with S. carnosus 833 matured more than 2 wk faster than control sausages. Maturity correlated significantly with higher amounts of branched‐chain aldehydes and alcohols and both branched‐ and straight‐chain methyl ketones—compounds arising from the breakdown of the amino acids leucine, isoleucine, and valine, or from microbial β‐oxidation of fatty acids. Also, sulfur compounds arising from added garlic correlated positively with mature flavor.
Composition, Liquid Leakage, and Mechanical Properties of Farmed Rainbow Trout: Variation Between Fillet Sections and the Impact of Ice and Frozen Storage
Authors: Mørkøre T. , Hansen A.Å. , Unander E. , Einen O.
Published: July 2006

ABSTRACT: Variation in quality characteristics within rainbow trout fillets, and changes in liquid leakage (LL) and mechanical properties during ice or frozen storage was studied. Fat, water, protein, and ash content, determined in frozen thawed samples, varied significantly among fillet sections. LL increased in the cranial‐caudal direction, and it was highest following freezing. Dorsally, compression and puncturing resistance increased towards the tail (raw and baked), but puncture resistance of raw fillets was highest in the belly flap. The results indicated pronounced softening of the tail‐half upon freezing. It is suggested that sectioning of trout fillets for different products or markets may improve utilization of intrinsic quality characteristics.
Conjugated Linoleic Acid and Fatty Acid Composition of Yogurt Produced from Milk of Cows Fed Soy Oil and Conjugated Linoleic Acid
Authors: Boylston T.D. , Beitz D.C.
Published: July 2006

ABSTRACT: Yogurt was processed from milk from Holstein cows whose diets were supplemented with soy oil (5%) and/or conjugated linoleic acids (CLA, 1%) to determine the effect of processing and dietary supplementation on CLA and fatty acid composition. Processing and storage for 7 d did not significantly affect CLA or fatty acid composition. CLA contents of milk and yogurt increased 2.8‐ and 2‐fold by soy oil and CLA supplementation, respectively. Contents of saturated fatty acids decreased and trans‐octadecenoic acids increased with the soy‐oil‐supplementation. The addition of CLA to soy‐oil‐supplemented diets did not significantly affect the CLA and fatty acid composition of the yogurt.
Pasture and Grain Finishing Affect the Color Stability of Beef
Authors: Lanari M.C. , Brewster M. , Yang A. , Tume R.K.
Published: July 2006

ABSTRACT: We determined the effect of pasture feeding (P0) or sorghum feeding with 2500 IU/head/d; (G2500) or without (G0) vitamin E supplementation on the color stability of gluteus medius (GM), longissimus lumborum (LL) and semimembranosus (SM). Diets did not affect the total pigment concentration of the muscle. Color stabilities were G2500 > P0 > G0 for fresh GM and SM and G2500 > G0 > P0 for fresh LL. Color stabilities of aged beef from the P0 and G2500 treatments were similar and higher than those from unsupplemented animals. Color stability of minced beef ranked as: P0 aged > G0 and G2500 fresh > P0 fresh > G0 and G2500 aged.
Antioxidative Effects of Ethanol Extracts from Rhus verniciflua Stoke on Yukwa (Oil Popped Rice Snack) Base During Storage
Authors: Park Y.S. , Kim Y.S. , Shin D.H.
Published: July 2006

ABSTRACT: This study was designed to evaluate the antioxidative effectiveness of ethanol extracts of Rhus verniciflua Stoke (RVE) in frying oil of Yukwa base (rice snack). RVE showed a strong antioxidant activity, but commercial antioxidants — BHA and dl‐δ‐tocopherol — did not demonstrate a significant ifmprovement over the control treatment (Yukwa bases prepared without any antioxidants and extracted oil from these). In particular, induction period, peroxide value, and acid value of RVE treatment exhibited a higher oxidative stability than that of the other treatments. In addition, the decrease in linoleic acid (C18:2)/palmitic acid (C16:0) ratio was much less than the other treatments. Texture properties (hardness and crispiness) of Yukwa base were not significantly different. Results showed strong antioxidant properties of RVE on Yukwa base during storage.
Enzymatically Modified Beef Tallow as a Substitute for Cocoa Butter
Authors: Osborn H.T. , Akoh C.C.
Published: July 2006

ABSTRACT: Dark “chocolate” samples were formulated with either cocoa butter (CB), randomized tallow (RT) made with Candida antarctica (SP 435) lipase, or a beef tallow: stearic acid structured lipid (SL) made by acidolysis using Rhizomucor miehei (IM 60) lipase. Fatty acid composition, thermal profile, solid fat content (SFC), hardness, and polymorphic structure were determined for the fats and/or “chocolate” samples. An accelerated fat bloom study was performed on the “chocolate” samples. Neither of the modified tallows had a detrimental effect on the crystallization of CB after proper tempering of the “chocolates.” RT did not soften the “chocolate” and both of the modified lipids reduced bloom rates.
Clarification of Citrus Juice is Influenced by Specific Activity of Thermolabile Pectinmethylesterase and Inactive PME‐Pectin Complexes
Authors: Ackerley J. , Corredig M. , Wicker L.
Published: July 2006

ABSTRACT: Thermolabile pectinmethylesterase (PME) from Valencia orange pulp was extracted, partially purified by cation exchange chromatography (IEX), and added to reconstituted orange juice at 2 units/ml. Of the juices that clarified, %T increased, cloud particle size increased and % degree of esterification (DE) decreased in the 15 d storage study. The rate of clarification was most rapid for juices with added PME extracts that never bound Hi‐Trap SP and contained 36 and 27 kDa peptide, intermediate for crude extracts of PME not applied to IEX, and lowest for PME extracts that bound Hi‐Trap SP and contained 36 and 13 kDa peptide. These results suggest that PME‐pectin complexes and low peptides moderate PME activity and juice clarification.
Properties of Proteolytic Enzymes from Muscle of Octopus (Octopus vulgaris) and Effects of High Hydrostatic Pressure
Authors: Hurtado J.L. , Montero P. , Borderías J. , An H.
Published: July 2006

ABSTRACT: The proteolytic activity of octopus arm muscle exhibited optimum activity at 40°C and 60°C, at optimum pH 2.5 and 4.0, respectively. The proteinases were inhibited strongly by cysteine‐ and aspartic‐proteinase inhibitors and, to a lesser degree, by serine‐proteinase inhibitors at 40°C, and by cysteine‐proteinase inhibitors at 60°C. High pressure did not modify the temperature and pH autolytic activity profiles. The autolytic activity at 40°C was reduced by high pressure; however, it was increased at an incubation temperature of 60°C, mainly in muscle pressurized at 7°C. Aspartic‐proteinase was the most sensitive to high pressure. The autolysis of myofibrillar proteins was reduced by high pressure, which was evident in MHC band.
Plum Storability Improved after Calcium and Heat Postharvest Treatments: Role of Polyamines
Authors: Valero D. , Pérez‐Vicente A. , Martínez‐Romero D. , Castillo S. , Guillén F. , Serrano M.
Published: July 2006

ABSTRACT: Plums were treated with calcium or heat (45°C) and then stored at 2°C for 28 d. Fruit firmness, ethylene, and CO2 production rates were investigated. The concentrations of endogenous polyamines (free, conjugated‐soluble, and cell wall‐bound) were also studied. Both treatments improved fruit firmness by increases in Magness‐Taylor force and force‐deformation ratio, and decreases in flesh deformation. No differences were found in either ethylene or respiration rate production among fruits due to the low storage temperature. Calcium‐treating plums increased the conjugated forms of putrescine (conjugated‐soluble and cell wall‐bound), which are related to higher firmness. Heat‐treated plums mainly increased cell wall‐bound spermidine, inducing a greater cell wall stability and plum firmness.
Antioxidant and Antimutagenic Activity of Dietary Chlorophyll Derivatives Determined by Radical Scavenging and Bacterial Reverse Mutagenesis Assays
Authors: Ferruzzi M.G. , Böhm V. , Courtney P.D. , Schwartz S.J.
Published: July 2006

In vitro antioxidant and antimutagenic activity of dietary chlorophyll derivatives was assessed. Antioxidant activity was determined by the ability of each compound to scavenge the long‐lived free radicals 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonate) (ABTS+). Antimutagenic activity was assayed with a modified microscreen bacterial reverse mutagenicity assay using Salmonella typhimurium TA100 and benzo[a]pyrene as the tester strain and mutagen respectively. Derivatives of chlorophyll a were found to be more effective radical quenchers than those of chlorophyll b. Furthermore, metal‐free derivatives such as chlorins, pheophytins, and pyropheophytins exhibited significantly lower antiradical capacity than metallo‐derivatives such as Mg‐chlorophylls, Zn‐pheophytins, Zn‐pyropheophytins, Cu‐pheophytina, andCu‐chlorophyllins. Both metal‐free and metallo‐chlorophyll derivatives demonstrated similar dose‐dependent inhibitory activity against B[a]P induced mutagenesis. These results demonstrate that dietary chlorophyll derivatives prevalent in both fresh and processed foods and dietary supplements have antioxidant and antimutagenic activities.
Influence of Raw Fish Quality on Some Physicochemical and Microbial Characteristics as Related to Ripening of Salted Anchovies (Engraulis encrasicholus L)
Authors: Hernandez‐Herrero M.M. , Roig‐Sagues A.X. , Lopez‐Sabater E.I. , Rodriguez‐Jerez J.J. , Mora‐Ventura M.T.
Published: July 2006

Influence of raw fish quality on the sensorial, physicochemical, and microbiological characteristics as related to ripening of salted anchovies has been studied. Raw fish remained iced for 4 d and samples were periodically taken for processing following traditional methods on d 0 (Extra: high quality fish), 2 (A: medium quality fish) and 4 (B: inedible as human food). The enzymatic activity is not suppressed when the ripening period is completed and alkaline proteinase activity dominates. No statistical differences were observed in the sensory assessment and in the majority of physicochemical and microbiological data obtained during the ripening process. However, differences are observed when raw material is of grade C (low quality fish), especially in the proteinase activity at pH 9.
Effects of Transglutaminase on SDS‐PAGE Patterns of Wheat, Soy, and Barley Proteins and their Blends
Authors: Basman A. , Köksel H. , Ng P.K.W.
Published: July 2006

Transglutaminase (TG) catalyzes the formation of nondisulfide covalent crosslinks between pep‐tide‐bound glutaminyl residues and ε‐amino groups of lysine residues in proteins. TG can be used for polymerizing proteins from 1 or more sources through formation of intermolecular crosslinks. This study investigated, by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, polymers created by the action of TG on proteins of wheat, soy, barley, wheat‐soy, and wheat‐barley blends. Electrophoretic results showed that with increasing incubation time, the crosslinking reaction is substantially increased, with progressive decrease or disappearance of some protein monomers. Densitometric results showed that soy proteins were the best substrates of TG while barley and wheat proteins were similar in reactivity.
Production of Off‐Odor Volatiles from Liposome‐Containing Amino Acid Homopolymers by Irradiation
Authors: Ahn D.U. , Lee E.J.
Published: July 2006

Irradiation not only generated many new volatiles but also destroyed some volatiles already present in nonirradiated amino acid homopolymer‐in‐liposome systems. The amounts of some volatiles greatly increased, but others significantly decreased after irradiation. The majority of newly generated and increased volatiles by irradiation were sulfur compounds, indicating that sulfur amino acids are the most susceptible to changes by irradiation. More than one site in amino acid side chains was labile to free radical attack, and many volatiles were produced by the secondary chemical reactions after the primary radiolytic degradation of side chains. Although nonirradiated samples also produced some sulfury notes, irradiated samples produced much a stronger and astringent sulfury odor than nonirradiated samples.
Modeling of Hexanal Sorption Kinetic in an Aldehydes Scavenger Film Intended for Food Packaging Applications
Authors: DelNobile M.A. , Buonocore G.G. , Fava P. , Piergiovanni L.
Published: July 2006

A mathematical model aimed to predict the hexanal sorption kinetic into an aldehyde scavenger film is presented. The proposed model is based on the assumption that the sorbed hexanal molecules are in part randomly dispersed into the polymeric matrix and in part chemically bonded to the polymeric matrix. To validate the model hexanal sorption kinetics were determined at 25°C and at 3 different hexanal activity. The proposed model satisfactorily fits the experimental data suggesting that hexanal absorption by the active film is a complex phenomenon involving both chemical reaction and physical reversible absorption.
Tomographic Techniques for Measuring Fluid Flow Properties
Authors: Choi Y.J. , Mccarthy K.L. , Mccarthy M.J.
Published: July 2006

Experimental fluid velocity profiles can be readily obtained by using tomographic techniques. Combining measurements of a fluid velocity profile with a simultaneous pressure drop permits the evaluation of rheological properties. In order to control a process and to assure product quality, it is useful to monitor the rheological properties in‐line or on‐line. Two tomographic techniques, magnetic resonance imaging (MRI) and ultrasonic Doppler velocimetry (UDV), were used to obtain velocity profiles for a 65.7 °Brix corn syrup solution and a 4.3 °Brix tomato juice. The UDV technique provided velocity profiles that compared well with the MRI method. For the corn syrup, the shear viscosity of 1.37 Pa‐s (UDV) and 1.51 Pa‐s (MRI) agreed well with the offline measurement of 1.57 Pa‐s. The tomato juice was best characterized as a Bingham plastic fluid. The yield stress ranged from 4.44 Pa to 4.70 Pa, which matched well with the off‐line value of 4.50 Pa. The strengths and limitations of both techniques are presented.
Rheological Characteristics of Pimento Purée: Theoretical Interpretation
Authors: Cepedaand E. , Gómez R.
Published: July 2006

Rheological characteristics of pimento purée were investigated at different temperatures (5 to 40 °C). The purée serum was a cloudy liquid (0to40 μm particles) with Newtonian behavior, and flow activation energy of 25.9 kJ/ mol. The power law model was applied to fit the pseudoplastic behavior of pimento purée. The activation energy for flow, evaluated with the Arrhenius‐Guzman equation, was low and depended on the variety. A modified Krieger‐Dougherty model with 2 parameters was proposed to describe the effect of wet pulp fraction on the relative viscosity. In the semi‐empirical model, the colloidal contribution to the viscosity at low shear rate and the parameter variations with the shear rate were considered.
Growth, Viability and Activity of Bifidobacterium spp. in Skim Milk Containing Prebiotics
Authors: Bruno F.A. , Lankaputhra W.E.V. , Shah N.P.
Published: July 2006

Growth, activity and mean doubling time (Td) of five Bifidobacterium species in the presence of four types of prebiotics, and concentrations of acetic and lactic acids were determinted during fermentation and after 4 weeks of refrigerated storage. The Td was lowest for B. animalis with raftilose and inulin. Retention of viability of bifidobacteria was greatest with hi‐amylose corn starch (hi‐maize). The average pH of skim milk at the end of 4 wks storage averaged 4.34 (for B. animalis with raftilose) to 4.07 (for B. longum with inulin). The highest levels of acetic acid and lactic acid were produced by B. pseudolongum with lactulose and B. infantis with lactulose, respectively.
New Improved Method for Evaluation of Growth by Food Related Fungi on Biologically Derived Materials
Authors: Bergenholtz K.P. , Nielsen P. V.
Published: July 2006

ABSTRACT: Biologically derived materials, obtained as commercial and raw materials (Polylactate (PLA), Polyhydroxybutyrate (PHB), potato, wheat and corn starch) were tested for their ability to support fungal growth using a modified ASTM G21‐96 (American Society for Testing and Materials) standard as well as a new method where 10 μl of a spore suspension is placed in a spot on the test sample. The new method gave additional information about fungal growth on biologically derived materials, revealing a clear difference between survival and growth. PHB and PLA turned out to be most suitable for food packaging application as no significant growth was seen within 28 d of incubation at 30°C.
Microstructure of Feta Cheese Made Using Different Cultures as Determined by Confocal Scanning Laser Microscopy
Authors: Hassan A.N. , Frank J.F. , Corredig M.
Published: July 2006

ABSTRACT: The objective of this work was to observe the microstructure of feta cheese using confocal scanning laser microscopy. Low fat cheese and cheese containing capsule‐producing cultures were made. The protein network was observed using the reflectance mode of the confocal microscope. Fat was stained by Nile red dye diluted with whey. More even distribution of fat with a larger number of smaller globules was observed in cheese made with noncapsule‐forming culture compared to that made with the capsule‐forming culture. Nonfat cheese had compact structure when made with noncapsule‐forming culture which contrasted with the open structure observed in cheese made with the capsule‐forming culture