bluuebunny/crossref_metadata_2025 huggingface dataset:
Prolonged exposure of naïve CD8+ T cells to interleukin‐7 or interleukin‐15 stimulates proliferation without differentiation or loss of telomere length
Authors: Wallace Diana L. , Bérard Marion , Soares Maria V. D. , Oldham Janine , Cook Joanne E. , Akbar Arne N. , Tough David F. , Beverley Peter C. L.
Published: July 2006

Interleukin (IL)‐7 and IL‐15 are cytokines implicated in homeostatic control of the peripheral CD8 T‐cell pool. We compared the effects of IL‐7 and IL‐15 on survival and proliferation of purified human CD8+ T‐cell subsets. Low concentrations of either cytokine reduced the spontaneous apoptosis of all subsets, and enhancement of survival corresponded to the extent of Bcl‐2 up‐regulation. Surprisingly, although minimal proliferation of naïve CD8+ T cells was observed during the first week of culture with cytokines, a marked expansion of these cells occurred at later time points, particularly in response to IL‐15. This occurred largely without phenotypic change or acquisition of effector function, indicating a dissociation of differentiation from proliferation. Notably, progression of naïve CD8+ T cells through several cell divisions resulted in up‐regulation of telomerase and the maintenance of telomere length. These data show that IL‐7 and IL‐15 induce cell proliferation and rescue from apoptosis in a concentration, time and subset‐dependent manner, and have implications for the homeostatic expansion of the naïve CD8+ T‐cell pool.
No evidence for the use of DIR, D–D fusions, chromosome 15 open reading frames or VHreplacement in the peripheral repertoire was found on application of an improved algorithm, JointML, to 6329 human immunoglobulin H rearrangements
Authors: Ohm‐Laursen Line , Nielsen Morten , Larsen Stine R. , Barington Torben
Published: July 2006

Antibody diversity is created by imprecise joining of the variability (V), diversity (D) and joining (J) gene segments of the heavy and light chain loci. Analysis of rearrangements is complicated by somatic hypermutations and uncertainty concerning the sources of gene segments and the precise way in which they recombine. It has been suggested that D genes with irregular recombination signal sequences (DIR) and chromosome 15 open reading frames (OR15) can replace conventional D genes, that two D genes or inverted D genes may be used and that the repertoire can be further diversified by heavy chain V gene (VH) replacement. Safe conclusions require large, well‐defined sequence samples and algorithms minimizing stochastic assignment of segments. Two computer programs were developed for analysis of heavy chain joints. JointHMM is a profile hidden Markow model, while JointML is a maximum‐likelihood‐based method taking the lengths of the joint and the mutational status of the VH gene into account. The programs were applied to a set of 6329 clonally unrelated rearrangements. A conventional D gene was found in 80% of unmutated sequences and 64% of mutated sequences, while D‐gene assignment was kept below 5% in artificial (randomly permutated) rearrangements. No evidence for the use of DIR, OR15, multiple D genes or VH replacements was found, while inverted D genes were used in less than 1‰ of the sequences. JointML was shown to have a higher predictive performance for D‐gene assignment in mutated and unmutated sequences than four other publicly available programs. An online version 1·0 of JointML is available at http://www.cbs.dtu.dk/services/VDJsolver.
The kinetics and phenotype of the human B‐cell response following immunization with a heptavalent pneumococcal‐CRM197 conjugate vaccine
Authors: Clutterbuck Elizabeth A. , Salt Penny , Oh Sarah , Marchant Arnaud , Beverley Peter , Pollard Andrew John
Published: July 2006

Primary immunization of infants with protein–polysaccharide conjugate vaccines induces antipolysaccharide antibody and is highly effective in preventing invasive disease caused by encapsulated bacteria. However, recent experience from the UK indicates that this immunity is not sustained in the absence of booster doses of vaccine. This study aimed to establish the kinetics and phenotype of B‐cell subpopulations responding to booster immunization with a heptavalent pneumococcal conjugate vaccine (Pnc7), which is to be introduced into the primary immunization schedule in the UK during 2006. Six adult volunteers received a booster dose of Pnc7 12–18 months after primary immunization. CD27hi CD38hi CD20+/– IgG antibody‐forming cells were detected in peripheral blood with maximum frequency at days 6–7 after immunization. This was accompanied by a more prolonged rise in memory B cells that required in vitro stimulation with Staphylococcus aureus Cowan strain and interleukin‐2 to induce antibody secretion. These data provide evidence for at least two subsets of antibody‐forming cells involved in the secondary humoral response to a glycoconjugate vaccine in primed individuals. A briefly circulating subset of B cells that spontaneously secrete immunoglobulin G may be responsible for early defence against re‐encountered encapsulated bacteria. However, the kinetics of the appearance of these cells may indicate that the humoral immune response is too slow in defence against an organism that invades within days of acquisition. The more sustained presence of a memory population may provide persistence of antipolysaccharide antibody after a booster dose of vaccine and may also include re‐circulatory populations responsible for further anamnestic responses.
Mackerel Cathepsins B and L Effects on Thermal Degradation of Surimi
Authors: JIANG SHANN‐TZONG , LEE BAI‐LIN , TSAO CHING‐YU , LEE JAI‐JAAN
Published: July 2006

During surimi processing, cathepsins B and L activities in minced, leached and NaCl‐ground meats were 6.02, 5.23, and 4.07 units/g, respectively. About 80% activity remained in surimi after 8 wk storage at −40°C suggesting that these proteinases were stable and difficult to remove. At 40°∼ 55°C, pH 6.5 ∼ 7.5, cathepsins B and L and purified cathepsin B had high hydrolytic activity on myosin heavy chain (MHC). The strength of surimi gel with cathepsins B and L or with purified B decreased (p < 0.05) after 2 hr incubation at 55°C. This suggested that the residual cathepsins B and L had MHC‐degrading activity and consequently caused gel softening.
Physical Properties of Whey Protein Stabilized Emulsions as Related to pH and NaCl
Authors: DEMETRIADES K. , COUPLAND J.N. , McCLEMENTS D. J.
Published: July 2006

Corn oil‐in‐water emulsions (20 wt%, d32∼ 0.6 μm) stabilized by 2 wt% whey protein isolate were prepared with a range of pH (3–7) and salt concentrations (0–100 mM NaCl), and particle size, rheology and creaming were measured at 30°C. Appreciable droplet flocculation occurred near the isoelectric point of whey protein (pH 4–6), especially at higher NaCl concentrations. Droplet flocculation increased emulsion viscosity and decreased stability to creaming. Results are related to the influence of environmental conditions on electrostatic and other interactions between droplets.
Concentration and Interactive Effects on the Sorption of Aroma Liquids and Vapors into Polypropylene
Authors: JOHANSSON F. , LEUFVÉN A.
Published: July 2006

The sorption of hexyl acetate and ethyl butyrate into polypropylene from vapors and 40% ethanol solution was studied. The effect of concentration and interactions with co‐sorbants was investigated. The vapors were sorbed in amounts that were related to feed concentrations, without any interactive effects of co‐sorbants, in the concentration range (i.e. 0.12–3.4 μg/mL) and the mixtures investigated. Compounds from a dissolved mixture, on the other hand, were generally sorbed in smaller amounts than from a single compound solution. Hexyl acetate was sorbed in larger amounts from a mixture of five compounds at high concentration (i.e. 1000 μg/mL each) than when it was the sole solute.
Hygroscopic Coatings Control Surface White Discoloration of Peeled (Minimally Processed) Carrots During Storage
Authors: CISNEROS‐ZEVALLOS LUIS , SALTVEIT MIKAL E. , KROCHTA JOHN M.
Published: July 2006

White discoloration on peeled carrots is partially due to surface dehydration which can be controlled with hygroscopic coatings: e.g., polyhydric alcohols and salt solutions. This study was performed at 2.5, 7.5, 10, and 15°C, using a model system controlling relative humidity at 33, 75 or 98% or a commercial system with low‐density polyethylene (LDPE) plastic film bags. The moisture sorption properties of propylene glycol, sorbitol, glycerol and calcium chloride enabled them to keep the carrot surface moist and maintain a transparent surface layer through which the underlying orange color was visible. This effect was only observed at high relative humidities (e.g., 98% RH). Similar effects were observed on treated peeled carrots stored in LDPE bags. The moisturized appearance provided by the hygroscopic coatings during storage was effective at several different temperatures.
Foaming Properties of Egg Albumen with a Bubbling Apparatus Compared with Whipping
Authors: BANIEL A. , FAINS A. , POPINEAU Y.
Published: July 2006

Neither standard method nor instrument exists to accurately measure foaming properties in food. Usually, whipping methods are used but they are only moderately reproducible. We used an original apparatus in which foam was generated by bubbling and then analyzed by conductimetry (liquid in the foam) and a uniline camera (foam volume). The foaming properties of a series of egg‐white powders were studied. Among parameters describing foam formation and destabilization, three were repeatable and discriminating. They were correlated with those obtained with whipping methods. Easy to use and rapid, the bubbling method is an alternative for controlling and measuring the foaming properties of egg‐white.
Antibacterial Activity of Heated Cabbage Juice, S‐Methyl‐L‐Cysteine Sulfoxide and Methyl Methanethiosulfonate
Authors: KYUNG KYU HANG , HAN DUCK CHUL , FLEMING HENRY P.
Published: July 2006

Autoclaved cabbage juice was inhibitory to growth of Staphylococcus aureus. S‐Methyl‐L‐cysteine sulfoxide (SMCSO), autoclaved either together with or separately from nutrient broth, also inhibited the growth of S. aureus, but inhibition was greater when SMCSO was autoclaved separately. Methyl methanethiosulfonate (MMTSO2), a thermal breakdown product of SMCSO, completely inhibited growth of S. aureus at 10 ppm. MMTSO2 was formed in both autoclaved samples of cabbage juice and aqueous solution of SMCSO. Thus, evidence indicates that the bacterial inhibitory activity in autoclaved cabbage juice was due to heatinduced formation of MMTSO2 from SMCSO.
Shelf Life of Sunflower Kernels
Authors: FRITSCH C. W. , HOFLAND C. N. , VICKERS Z. M.
Published: July 2006

One raw and two oil roasted samples of sunflower kernels packaged in paper bags and in two types of low oxygen atmosphere pouches were stored at 5, 21 and 38°C. Quality of the stored samples was monitored by an expert sensory panel, peroxide, hexanal, free fatty acids and moisture determinations. Liking ratings, obtained with 99 consumers after 24 wk storage, were used to select end points for expert sensory ratings. The shelf life for roasted sunflower kernels was greater than 12 month when stored in nitrogen flushed pouches and as low as 8 wks when exposed to air at 38°C. Hexanal was a better index for shelf life of roasted sunflower kernels than was peroxide. The shelf life of raw sunflower kernels was > 12 month in packages providing some moisture but no oxygen protection.
Fractional Conversion for Determining Texture Degradation Kinetics of Vegetables
Authors: RIZVI A.F. , TONG C.H.
Published: July 2006

Fractional conversion (f) takes into account the nonzero texture property upon prolonged heating. This was applied as an alternate technique for reanalyzing texture degradation kinetics based on published data which indicated that the softening of vegetables followed a dual mechanism first order kinetic model. The plot of the logarithm of 1‐f vs heating time was linear through log cycles indicating the reaction was first order with a single rate constant and the substrate b was better characterized by the equilibrium (or maximum retainable) texture property. A possible explanation was developed for negative activation energies which had been reported for the second mechanism with some vegetables.
Gelatin from cod skins as affected by chemical treatments
Authors: GUDMUNDSSON MAGNÚS , HAFSTEINSSON HANNES
Published: July 2006

Concentrations of sodium hydroxide, sulfuric and citric acids used in processing gelatin from cod skins affected both yield and quality. The highest yield of gelatin was obtained when low concentrations [0.1–0.2% (w/v)] of sulfuric acid and sodium hydroxide were applied to the skins followed by treatment with 0.7% (w/v) citric acid. The effects on bloom value, viscosity, odor, clarity, color and pH of the gelatin varied. However, the use of 0.7% (w/v) citric acid in different combinations with sodium hydroxide and sulfuric acid usually gave best results. Freezedried gelatin had considerably higher bloom value than air‐dried gelatin.
Non‐Starch Polysaccharides and in Vitro Starch Digestibility of Raw and Cooked Chick Peas
Authors: PERIAGO M. J. , ROS G. , CASAS J. L.
Published: July 2006

The effects of domestic and industrial cooking methods on the non‐starch polysaccharides (NSP) content and in vitro starch digestibility of chick pea (variety “blanco lechoso”) have been studied. Total and soluble NSP increased, as did the slowly digestible starch (SDS), whereas the resistant starch (RS) fraction decreased after cooking, showing higher content in domestic than industrially cooked chick peas. The in vitro starch digestible rate index (SDRI) was similar in the cooked chick peas, as was the rapidly available glucose (RAG). Due to the low values of RAG, chick peas would give a slow post‐prandial glycaemic response. Domestic cooked chick peas consumption would increase the intakes of RS in human diet, whereas the industrially cooked chick peas with lower content of RS would result in less flatulence problems.
Phenoloxidases in Portabella Mushrooms
Authors: ZHANG XIAODONG , FLURKEY WILLIAM H.
Published: July 2006

Tyrosinase, laccase, and peroxidase activities were detected in crude extracts from commercial Portabella mushrooms. Tyrosinase was present in larger amounts than either laccase or peroxidase. Catechol showed the greatest activity as a substrate for tyrosinase while diaminobenzidine was found to be a good substrate for estimating laccase and peroxidase activity. Two tyrosinase and three laccase isoforms were detected after native electrophoresis. At least 10 tyrosinase isoforms were observed after isoelectric focusing. The distribution of these forms varied in different tissues. Browning reactions in Portabella mushrooms are a result of tyrosinase rather than laccase or peroxidase.
Soy Sauce Classification by Geographic Region Based on NIR Spectra and Chemometrics Pattern Recognition
Authors: IIZUKA KEIKO , AISHIMA TETSUO
Published: July 2006

Statistical and artificial neural network (ANN) pattern recognition techniques were applied to NIR spectra of 38 soy sauce samples collected from the northern/central, western, and southern regions in Japan and related to differences in food flavorings. Linear discriminant analysis (LDA) and ANN using factor scores calculated from NIR spectra showed more accurate differentiations than those based on the original spectra. In LDA, the correctly assigned ratio was 81.6%. Correct classification ratios shown by Partial least squares (PLS2) were 84.2% and by ANN 76.3% in the cross‐validation test. The differentiations suggested that there are quality differences in soy sauce among the three regions in Japan.
Thermal Stability of Invertase in Reduced‐Moisture Amorphous Matrices in Relation to Glassy State and Trehalose Crystallization
Authors: CARDONA SILVIA , SCHEBOR CAROLINA , BUERA MARÍA P. , KAREL MARCUS , CHIRIFE JORGE
Published: July 2006

The thermal stability of enzyme invertase in reduced‐moisture model systems of maltodextrin (MD), polyvynilpyrrolidone (PVP; MW 40,000) and trehalose heated at 90°C was studied. Significant invertase inactivation was observed in heated glassy PVP and MD systems kept well below their glass transition temperature (Tg), but the enzyme was fairly stable in rubbery trehalose systems. However, at moisture contents which allowed trehalose crystallization rapid thermal inactivation of invertase was observed. Invertase inactivation in heated PVP, MD and trehalose systems of reduced‐moisture could not be predicted on the basis of glass transition and this was particularly true for trehalose. Conditions which would allow collapse of the systems and crystallization of trehalose were fairly well predicted based on the estimated Tg of model systems.
Extraction Conditions and Moisture Content of Canola Flakes as Related to Lipid Composition of Supercritical CO2 Extracts
Authors: DUNFORD NURHAN TURGUT , TEMELLI FERAL
Published: July 2006

Canola flakes obtained before and after conventional cooking were extracted with supercritical carbon dioxide (SC‐CO2) at 35–75°C and 20.7–62.0 MPa. Moisture content was adjusted to 12.7–42.5% (w/w, moisture‐and oil‐free basis). Moisture content of residual flakes after extraction was monitored. Amount of extract recovered increased with increasing temperature and pressure, except at 20.7 MPa pressure it decreased with temperature indicating a crossover of the solubility isotherms. Some water was co‐extracted with canola oil. Free fatty acid (FFA) concentration of the extracts increased with decreasing pressure due to a decrease in triglyceride (TG) solubility. Oleic and linolenic acids had highest concentrations in the FFA fractions of all extracts. The lowest TG content of extracts was attained at 20.7 MPa and 75°C. The effect of extraction conditions was more pronounced than seed pre‐treatments on yield and composition of SC‐CO2 extracts.
Survival of Brevibacterium linens (ATCC 9174) after Spray Drying, Freeze Drying, or Freezing
Authors: TO BRIAN C.S. , ETZEL MARK R.
Published: July 2006

The objectives of this work were to: (1) contrast spray drying, freeze drying and freezing for large‐scale preservation of B. linens, (2) determine the thermal resistance curves, and (3) measure the storage stability. When B. linens was freeze‐dried and frozen in feed suspensions containing 3% (w/v) cell paste and 25% (w/w) total solids, survival was 100%. During spray drying, lethal thermal injury was the main cause of loss of viability. Accordingly, by extrapolation, 100% viability would be possible at an outlet‐air temperature of 57°C. Spray‐dried and freeze‐dried cells were stable during storage at 4°C in the absence of oxygen and moisture.
Fermentation and Properties of Calcium‐fortified Soy Milk Yogurt
Authors: YAZICI F. , ALVAREZ V.B. , HANSEN P.M.T.
Published: July 2006

Calcium‐fortified soy milk yogurt containing 190 mg calcium/100g was produced and evaluated for textural and microstructural properties. The soy milk base contained 10% full fat soy flour, 2.25% soy protein isolate, 2.75% high fructose corn syrup, 1.55% calcium lactogluconate, and 1.25% potassium citrate. The mixture was heated 5 min at 80°C, cooled to 42°C, and inoculated with yogurt cultures. Calcium‐fortified soy milk required a higher rate of inoculation (5%) than non‐fortified soy milk (2.5%) and had higher titratable acidity and more syneresis. Calciumfortified soy milk yogurts showed comparable gel strength with that of commercial regular yogurt. Gels from nonfortified soy milk yogurts were hard and brittle. Addition of calcium did not significantly affect microstructure of the yogurts.
Accumulation of Some Flavor Compounds in Full‐ and Reduced‐fat Cheddar Cheese Under Different Ripening Conditions
Authors: CHIN H.W. , ROSENBERG M.
Published: July 2006

Reduced‐fat cheese showed higher levels of ethanol and lower acetoin than full‐fat samples throughout ripening regardless of conditions. Total headspace volatiles, as well as butanoic and hexanoic acids, increased with ripening time and temperature. Full‐ and reduced‐fat cheeses developed distinctly different headspace volatile profiles throughout ripening. The effects of ripening conditions were more notable in full‐fat samples. Ripening reduced‐fat Cheddar cheese at an elevated temperature for a limited time may enhance development of some desirable volatiles such as butanoic acid.
Functional and Immunological Properties of Casein Hydrolysate Produced from a Two‐Stage Membrane System
Authors: LIN SHIH‐BIN , CHIANG WEN‐DEE , CORDLE CHRISTOPHER T. , THOMAS RONALD L.
Published: July 2006

A uniform hydrolysate with a relatively low free amino acid content (<5%) was produced from bovine casein with a commercial protease (Alcalase) in a two‐stage membrane reactor. The trichloroacetic acid‐soluble nitrogen was 98.68% and degree of hydrolysis was 23.2% for the second‐stage hydrolysate. The retained immunologically active casein was 2.32% and whey protein was 1.09% in the hydrolysate as determined by ELISA. The second‐stage protein hydrolysate was completely soluble at 2% (w/v) from pH 3.0 to 9.0. Water sorption increased two to four times at water activities of 0.33 to 0.95 as compared to untreated casein.
Composition, Solubility and Emulsifying Properties of Granules and Plasma of Egg Yolk
Authors: ANTON M. , GANDEMER G.
Published: July 2006

Yolk was fractionated by a low speed centrifugation into granules and plasma. The composition, solubility and emulsifying properties of granules and plasma were compared to those of industrial spray‐dried yolk. Granules contained about half the lipids and cholesterol and about double the proteins of yolk and plasma. Yolk and granules required an ionic strength ≥ 0.3M sodium chloride to become solubilized at pH 7.0, whereas plasma was solubilized at any ionic strength. At about 80% solubility, yolk, granules and plasma had similar emulsifying activities and granules had the best emulsion stabilization. Results suggest that granules could be used as stabilizers in food emulsions.
Production of Restructured Meat using Microbial Transglutaminase without Salt or Cooking
Authors: KURAISHI CHIYA , SAKAMOTO JIRO , YAMAZAKI KATSUTOSHI , SUSA YASUYUKI , KUHARA CHIHO , SOEDA TAKAHIKO
Published: July 2006

To produce restructured meat, microbial transglutaminase (MTGase) was evaluated for its ability to introduce covalent crosslinks between protein molecules. Pork muscle cubes were mixed with MTGase and held at 5°C for 2 hr for the enzyme reaction. Restructured products were analyzed for binding strength without cooking. MTGase treatment resulted in effective binding of meat pieces provided there was addition of salt (NaCl). To ensure proper binding without NaCl, some food proteins with MTGase were also investigated. Meat cubes in combination with MTGase and sodium caseinate showed acceptable bind, and sodium caseinate appeared to be a superior substrate for the crosslinking to meat proteins than soy protein, whey protein, or gelatin. These results suggest a useful method for producing restructured meat which can be distributed in the raw, chilled state.
Hydration Kinetics of Red Kidney Beans (Phaseolus vulgaris L.)
Authors: ABU‐GHANNAM NISSREEN , McKENNA BRIAN
Published: July 2006

Soaking of dry red kidney beans was studied at 20, 30 40 and 60°C by the method of weight gain until equilibrium conditions were attained. Water absorbed during soaking was a function of both soaking time and temperature. Soaking at high temperatures increased the hydration rate constant and decreased soaking time to achieve equilibrium. Compared to unblanched beans, the application of a pre‐blanching step considerably reduced hydration times of blanched beans. Due to the plasticity effect acquired upon blanching, blanched beans showed a significantly high hydration rate constant and exhibited a more constant equilibrium moisture content regardless of soaking temperature. Activation energy values (Ea) of the hydration process were 6.48 Kcal/mole for blanched and 14.25 for unblanched beans.
Calcium Bioavailability from High Oxalate Vegetables: Chinese Vegetables, Sweet Potatoes and Rhubarb
Authors: WEAVER C.M. , HEANEY R.P. , NICKEL K.P. , PACKARD P.I.
Published: July 2006

Absorption of calcium from high calcium vegetables endogenously labeled with 45Ca was studied in premenopausal women using a randomized cross over design. Chinese (C.) vegetables are a major source calcium, but the bioavailability is unknown and likely affected by oxalic acid content. Calcium absorption from Chinese vegetables, sweet potatoes, and rhubarb, was compared to milk at the same calcium level for calculation of an absorption index. Calcium absorption generally reflected oxalic acid content. Calcium absorption index (X±SEM) was least for C. spinach (0.257±0.0228) and rhubarb (0.235±0.0233), intermediate for sweet potatoes (0.423±0.0255), and highest for C. mustard greens (1.097±0.0532) and C. cabbage flower leaves (1.097±0.0532).
Fluorometric Assay for Screening Antioxidative Activity of Vegetables
Authors: FURUTA S. , NISHIBA Y. , SUDA I.
Published: July 2006

A fluorometric assay for evaluating antioxidative activities was principally based on inhibition of lipid peroxidation accompanied by the autoxidation of linoleic acid. It could estimate the antioxidative activities of vegetable extracts as well as known antioxidants in a linear response. All analytical procedures could be performed within a few hours using one test tube. The assay enabled testing a large number of samples treated at one time and application to vegetables containing pigments.
Pre‐Chill Spray of Chicken Carcasses to Reduce Salmonella typhimurium
Authors: LJ YANBIN , SLAVIK MICHAEL F. , WALKER JOEL T. , XIONG HUA
Published: July 2006

A test chamber was designed and constructed and prechill chicken carcasses inoculated with Salmonella typhimurium were treated in it. They were sprayed with tap water, 0.85% sodium chloride (NaCl), 5% or 10% trisodium phosphate (TSP), 5% or 10% sodium bisulfate (SBS), 0.1% cetylpyridinium chloride (CPC), or 1% lactic acids (LAC) at 207, 345 or 827 kPa pressure for either 30 or 90 sec exposure time. Samples were taken from carcass wash water to determine the most probable number of Salmonella. Compared to tap water spraying, 0.85% NaCl spraying did not significantly reduce Salmonella. The greatest reductions of S. typhimurium, by 10% TSP, 10% SBS, 0.1% CPC or 1% LAC spraying, were 3.7, 2.4, 1.6 or 1.6 log in 90 sec treatments, respectively.
Disinfection of Rice Seeds Prior to Sprouting
Authors: PIERNAS V. , GUIRAUD J.P.
Published: July 2006

Different methods of rice seeds disinfection were investigated in order to limit the development of micro‐organisms during sprouting. At room temperature, sodium hypochlorite at 1000 ppm or hydrogen peroxide resulted in a 2 to 3 log decrease in aerobic plate counts. Ethanol was found to inhibit germination, thus prohibiting its use. The limited effectiveness of decontaminating solutions could be because they did not access the bacteria, which was supported by the results of washing with benzalkonium chloride. Greater reduction (up to 5 log) was obtained by soaking seeds for 5 min in a sodium hypochlorite solution at 60°C.
Sensory and Chemical Characteristics of Selected Gulf of Mexico Coastal Herring Species
Authors: JAHNCKE MICHAEL L. , GOOCH JANET A.
Published: July 2006

Gulf of Mexico coastal herrings may become an important alternative fisheries resource for U.S. commercial fisherman. Effects of on board handling on sensory characteristics of chub mackerel (Scomber japonicus) and rough scad (Trachurus lathami) were investigated. Proximate and fatty acid composition of chub mackerel, rough scad, round scad (Decapturus punctatus), round herring (Etrumeus teres), and silver rag (Ariomma bondi) were determined to provide nutritional and product formulation data. Chub mackerel and rough scad had similar sensory characteristics found in other commercial species, which, with proper on board handling, could be maintained during frozen storage. Proximate and fatty acid compositions of the fish varied by species, season, and year.
Retention of Phytochemicals in Fresh and Processed Broccoli
Authors: HOWARD LENORA A. , JEFFERY ELIZABETH H. , WALLIG MATTHEW A. , KLEIN BARBARA P.
Published: July 2006

Our objective was to determine whether steam blanching, storage and preparation affected concentrations of sulforaphane (SF), sulforaphane nitrile (SFN), cyanohydroxybutene (CHB), iberin (I) or iberin nitrile (IN) in fresh and frozen broccoli. Broccoli (var. “Arcadia”) was grown in St. Charles, IL over three seasons. Samples were steam blanched (2 min at 93 ± 5°C) within 24h of harvest, frozen and stored at −20°C up to 90 days, and fresh broccoli was stored at 4°C up to 21 days. Samples were analyzed uncooked or microwave cooked. SF, SFN, I, IN and CHB were determined by GC in dichloromethane extracts from lyophilized samples. Rates of loss for CHB and SF were similar during storage of fresh broccoli. Blanching, storage, and microwave cooking decreased (p < 0.01) concentrations of each compound in fresh and frozen broccoli.
Pectic Enzyme Treatment Effects on Quality of White Grape Musts and Wines
Authors: LAO CONXITA , LÓPEZ‐TAMAMES ELVIRA , LAMUELA‐RAVENTÓS ROSA M. , BUXADERAS SUSANA , DE LA TORRE‐BORONAT M. DEL CARMEN
Published: July 2006

Grapes of three white cultivars were treated with a commercial pectic enzyme preparation on an industrial scale. The effect of enzyme treatment on the following juice and wine volatiles was considered: fruity esters, terpenes, alcohols, volatile phenols (4‐vinylphenol and 4‐vinylguaiacol), hydroxycinnamate derivative esters (caftaric, coutaric, and fertaric esters), and free hydroxy cinnamic acids (caffeic, coumaric and ferulic acids). Pectic enzyme treatment increased the higher alcohols, free hydroxycinnamic acids and volatile phenols, whereas amounts of most esters, herbaceous alcohols and hydroxycinnamate derivative esters were reduced. Terpenes, 2‐phenylethanol and benzyl alcohol levels were not affected by pectic enzyme treatment. When tasted by an expert panel, differences were found in sensory characteristics, with wines from untreated judged higher quality than those from treated grapes.
Comparison of Spray‐drying, Drum‐drying and Freeze‐drying for β‐Carotene Encapsulation and Preservation
Authors: DESOBRY STEPHANE A. , NETTO FLAVIA M. , LABUZA THEODORE P.
Published: July 2006

Pure β‐carotene was encapsulated in 25 Dextrose Equivalent maltodextrin by three drying processes (spray, freeze and drum). Stability was studied at 11% and 32% RH and 25°C, 35°C and 45°C. No significant influence of %RH was observed on the retention of β‐carotene. Oxidation followed first order kinetics with an initial fast first order reaction followed by a second much slower first order reaction period. Although drum‐drying caused more initial loss in drying, the lower surface carotenoids and larger particle size resulted in greater stability as compared to the other methods. The chromametric measurements of “L” and “a” corresponded to the other kinetics and indicated that the first period rapid loss corresponded to the oxidation of surface carotenoids.
Standardized Failure Compression Test of Protein Gels from a Collaborative Study
Authors: LEE C.M. , FILIPI I. , XIONG Y. , SMITH D. , REGENSTEIN J. , DAMODARAN S. , MA C‐Y. , HAQUE Z.U.
Published: July 2006

A failure compression test with a standardized procedure for protein gelation was developed. Using whey protein concentrate, egg white protein and soy protein isolate as representative proteins, a highly reproducible procedure for sample preparation and gel testing was developed after refinements. Gels of varying protein concentrations were prepared with 0.1 M NaCl at pH 7. Force (N) and strain (Δh/h) at failure were the main parameters measured. Variability of results was found due to uncontrolled conditions for protein hydration and pH adjustment and air incorporation during hydration. After corrective steps to avoid potential errors, the procedure was recommended for a routine analysis of failure properties of protein gels.
High‐Pressure‐Induced Gel of Sardine (Sardina pilchardus) Washed Mince as Affected by Pressure‐Time‐Temperature
Authors: PÉREZ‐MATEOS M. , MONTERO P.
Published: July 2006

Response surface methodology was used to determine how interactions of pressure (150–500 MPa), time (10–30 min) and temperature (0–75°C) affected gelling of sardine washed mince (2.5% NaCl) as compared with conventional heat processing at atmospheric pressure. The best conditions for optimum rheological parameters were pressure around 300 MPa, chilled temperature (< 10°C) and short processing times (10 min). Pressurizing considerably improved the rheological values of a mince which exhibited low gel‐forming ability under conventional heat treatment.
Non‐Volatile Components Effects on Quality of “Serrano” Dry‐cured Ham as Related to Processing Time
Authors: FLORES MÓNICA , ARISTOY M‐CONCEPCION , SPANIER ARTHUR M. , TOLDRÁ FIDEL
Published: July 2006

Following long dry‐curing periods, Spanish “Serrano” ham develops a specific “dry‐cured ham” flavor. To determine the effects of length of curing on flavor generation, replicate hams were processed for 7 or 12 mo prior to amino acid, peptide, and flavor evaluation by reverse phase HPLC, capillary zone electrophoresis, and sensory analysis, respectively. Generation of dry‐cured and pork flavors correlated with the accumulation of amino acids. The relation of these components with sensory descriptors was examined by factor analysis. Results indicated that combinations and proportions of taste‐active components produced the specific dry‐cured flavor characteristic rather than an accumulation of any single flavor component.
Physical Factors Related to C18 Adsorption Columns for Debittering Protein Hydrolysates
Authors: LIN SHIH‐BIN , NELLES LYNN P. , CORDLE CHRISTOPHER T. , THOMAS RONALD L.
Published: July 2006

A C18 column for debittering casein hydrolysates was tested for life‐span (70 debittering cycles), diameter‐to‐height ratio (D/H) (1.33‐5.0), linear flow rate (LFR) (200‐400 cm‐hr‐1), and scale‐up ability (13‐fold). The product quality and yield (69–72%) were consistent within these ranges of test conditions. The debittering capacity was about 0.6g loaded sample g‐1 C18. Columns were functional with feed concentrations (FC) as high as 30% (w/v).
Gelation of Egg White Proteins as Affected by Combined Heating and Freezing
Authors: XU JINQUAN , SHIMOYAMADA MAKOTO , WATANABE KENJI
Published: July 2006

Combined effects of preheating (60°C, 0 ∼ 30 min) and freezing (– 10 or –20°C, 20 hr) on the gelation of dried egg white induced by reheating (80°C, 30 min) were examined in comparison with those of refrigerating (5°C, 20 hr). Refrigeration consistently induced harder gels, while freezing resulted in either harder or softer gels. Results of soluble protein content, turbidity, SDS‐PAGE and gel filtration indicated that the unfolded and aggregated levels of ovotransferrin, caused by the cooperative effects of preheating and freezing or refrigerating, mainly determined the characteristics of gel properties.
Interaction of Commercial Dairy Proteins and Chicken Breast Myosin in an Emulsion System
Authors: IMM J.Y. , REGENSTEIN J.M.
Published: July 2006

The compatibility of commercial dairy proteins with chicken breast myosin in an emulsion system was examined. SDS‐PAGE of the solution remaining after emulsion formation indicated that myosin incorporation into the cream layer was much more limited with the flexible additives such as sodium‐caseinate and milk protein isolate resulting in decreased emulsion stability. However, myosin incorporation and emulsion stability were maintained with whey protein concentrate or whey protein isolate at all additive levels. No hydrophobicity changes were found in myosin with additive mixtures except for heated myosin and WPC (P=0.04). The stability of an emulsion was primarily determined by the amount of myosin incorporated.
Natural Antioxidants for Preventing Color Loss in Stored Paprika
Authors: OSUNA‐GARCIA JORGE A. , WALL MARISA M. , WADDELL CYNTHIA A.
Published: July 2006

Oxidative carotenoid degradation causes paprika color loss during storage. Ethoxyquin, a synthetic antioxidant, is used in the spice industry to prevent carotenoid loss during postharvest handling. However, ethoxyquin treated paprika is unacceptable for some markets and consumers. Naturally derived antioxidants, i.e., rosemary extracts, ascorbic acid, δ‐tocopherol, and mixed tocopherols were tested as color protectants in two paprika cultivars. Extractable color, surface color and carotenoid concentrations were determined before storage and then monthly. After 4 mo storage at ambient temperature, the control treatment lost 63% of the initial extractable color, the δ‐tocopherol treated samples lost 32%, and the ethoxyquin lost 6% color.
Anisotropy in Tensile Properties of Mozzarella Cheese
Authors: AK M. MEHMET , GUNASEKARAN SUNDARAM
Published: July 2006

Effects of sampling direction (parallel or perpendicular to protein fiber orientation), cheese type (low‐moisture, part‐skim, LMPS and reduced fat, RF) and deformation rate (5 and 25 cm/min) on fracture properties of Mozzarella cheese were determined with tensile tests. The fracture toughness, stress, and strain in the parallel direction were, respectively, 2.8, 2.1 and 1.4 times greater than those in the perpendicular direction. This verified that the Mozzarella cheese had anisotropic tensile properties. A composite‐material approach was used to explain the direction‐dependent properties. The toughness, stress, and strain values for RF cheese were, respectively, 5.9, 5.4, and 1.3 times those of LMPS cheese. The tensile properties of Mozzarella were also affected by deformation rate.
Osmotic‐Convective Dehydrofreezing Process for Drying Kiwifruit
Authors: ROBBERS MICHAEL , SINGH R. PAUL , CUNHA LUIS M.
Published: July 2006

Osmotic and convective dehydrofreezing were studied to determine sugar concentration, ascorbic acid loss, and texture changes in dried and dehydrofrozen kiwifruit. Two concentrations of sucrose (60° and 72° Brix) were used as osmotic solutions after convective air drying. Time needed to reach desired moisture was reduced with combined drying compared with osmotic drying. Firmness was evaluated by the maximum force from a back extrusion test. A reduction in maximum force was observed after freezing, as compared with fresh and dried fruit. Addition of ascorbic and citric acid as antioxidants in the osmotic solution prevented browning, and significant loss of ascorbic acid during osmotic drying. Air drying at 30°C produced distinguishable color changes.
Cyclodextrin Complexed Flavors Retention in Extruded Starches
Authors: KOLLENGODE ANANTHA N.R. , HANNA MILFORD A.
Published: July 2006

Corn starch (25% amylose) was blended with cyclodextrin‐complexed cinnamaldehyde, eugenol, nonanoic acid or 3‐octanone and extruded in a C. W. Brabender twin screw extruder. Radial expansion ratios, specific mechanical energy (SME) and flavor retained compound were influenced by flavor type. Comparisons of blending flavors prior to extrusion and injection of flavors during extrusion were made with cyclodextrin‐complexed flavors. Radial expansion ratio and SME were affected by method of flavor addition. Recoveries of 70 to 100% were obtained in extradates using cyclodextrin‐complexed flavors.
Lipid Fractions of Dry Fermented Sausages Change when Starter Culture and/or Aspergillus Lipase are Added
Authors: ZALACAIN I. , ZAPELENA M.J. , DE PEÑA M.P. , ASTIASARÁN I. , BELLO J.
Published: July 2006

Six levels of Aspergillus sp. lipase were evaluated and 0.400u/g was selected. A sausage with a starter culture (Lactobacillus plantarum (10%)+Staphylococcus carnosus (90%)), one with lipase and one with both starter culture and lipase were produced in a pilot plant. A lower amount of Micrococcaceae was found in sausages without starter culture. Total FFA quantity at the 15th day was higher in sausages with lipase. Higher amounts of acetic, propionic and butyric acids were found in sausages with both lipase and starter culture. Odor intensity had slightly higher scores in sausages with added lipase.
Residence Time Distribution of Particles during Two‐Phase Non‐Newtonian Flow in Conventional as compared with Helical Holding Tubes
Authors: SANDEEP K.P. , ZURITZ C.A. , PURI V.M.
Published: July 2006

The residence times of multiple particles during the flow of a non‐Newtonian suspension through a conventional holding tube assembly were compared with that in a helical holding tube assembly of identical length and tube diameter. The residence times were measured for different combinations of process parameters (viscosity, flow rate of fluid, size and concentration of particles). The effects of these parameters on Residence Time Distribution (RTD) of particles was determined and dimensionless equations were developed to predict the mean, minimum and standard deviation of residence times. The RTDs in the helical holding tube were found to be narrower than in the conventional holding tube. The RTD of particles at all combinations of process parameters were normally distributed. The ratio of mean to minimum residence time was within 1.05 to 1.11 in the helical holding tube and 1.06 to 1.16 in the conventional holding tube for the range of parameters studied.
Kinetic Properties of (+)‐Catechin Oxidation by a Basic Peroxidase Isoenzyme from Strawberries
Authors: LÓPEZ‐SERRANO M. , BARCELÓ A. ROS
Published: July 2006

The ability of a partially‐heat stable strawberry (Fragaria × ananassa) peroxidase to oxidize (+)‐catechin was studied and its oxidation followed the accepted model for peroxidase oxidations. Compound I (CoI) and compound II (CoII) were the main intermediates in the catalytic cycle. The reactivity of strawberry peroxidase with H2O2 [K1= 2.63 μM‐1 s‐1] and with (+)‐catechin [k3= 0.57 μM‐1 s‐1] suggested that (+)‐catechin is an excellent o‐diphenol for CoII reduction. The strong cooperativity of this peroxidase isoenzyme indicates its great efficacy in oxidation of (+)‐catechin at low H2O2 concentrations.
Pecan Oil Recovery and Composition as Affected by Temperature, Pressure, and Supercritical CO2 Flow Rate
Authors: ALEXANDER W.S. , BRUSEWITZ G.H. , MANESS N.O.
Published: July 2006

Effects of supercritical CO2 flow rate, extraction temperature, and pressure were studied on oil recovery, fatty acid composition, and factors that control solute extraction from intact pecan halves. After an initial solubility dominant period, extraction was influenced by diffusion of oil from within the pecan. The effective diffusion coefficient was 9.76 × 10‐12 m2/s. In the first 105 min, more oil was extracted as CO2 flow increased from 1.0 to 7.5 standard L/min (slpm). Beyond 120 min, increasing CO2 flow from 4 to 7.5 slpm produced negligible differences in amounts of extracted oil. At 2.5 slpm CO2 flow and 45–75°C, the oil extracted increased by 60% when pressure increased from 41.3 to 55.1 MPa and yielded slightly more at 66.8 MPa. Temperature, pressure, micrometering valve temperature, cultivar (but not extraction time) affected fatty acid (palmitic, stearic, oleic, linoleic, and linolenic) composition of pecan oil.
Process Optimization for Soft Tofu
Authors: SHIH M.C. , HOU H.J. , CHANG K.C.
Published: July 2006

Response surface methodology (RSM) was used to determine the optimum combinations of four factors, solids content of soy milk (10–14 °Brix), concentration of coagulant (0.25–0.41%, W/V), mixing temperature (75–91°C) and stirring time (5–25 sec) for producing soft tofu on a small pilot scale. Neither brittleness nor elasticity of the top part of tofu were influenced significantly by any factors. Yield was affected (p < 0.05) by soymilk solids content and coagulant concentration. Solids and protein content of tofu were affected (p < 0.05) by 3 factors except mixing temperature. Solids content of soy milk was the most important factor affecting texture. Optimum combinations were soymilk solids 11.8 to 12.3 °Brix, coagulant 0.27 to 0.32%, mixing temperatures 85 to 91°C, and stirring times 5 to 11.3 sec.
Optimization of Yogurt Production Using Demineralized Whey
Authors: PENNA ANA LUCIA B. , BARUFFALDI RENATO , OLIVEIRA MARICÊ N.
Published: July 2006

The effect of three independent fermentation variables: demineralized whey powder (0.0; 1.5 and 3.0%), lactic culture concentration (1.0; 2.0 and 3.0%) and mix treatment temperature (85; 90 and 95°C) was studied. Fermentation time to reach pH 4.3, instrumental consistency and appearance, visual consistency and taste of the product were evaluated. Product consistency increased as mix treatment temperature increased and demineralized whey powder decreased. The powder had a stronger influence on instrumental consistency than did temperature. Appearance was better when whey powder was used at 1.4 to 1.6%. Visual consistency decreased as whey powder increased but addition of demineralized whey powder did not negatively affect yogurt flavor.
Low‐energy Electron Effects on the Sterility and Viscosity of Grains
Authors: HAYASHI TORU , TAKAHASHI YOKO , TODORIKI SETSUKO
Published: July 2006

Microbial load and viscosity of brown rice, rough rice, wheat and buckwheat exposed to electrons at different acceleration voltages were examined and compared with those irradiated with gamma‐rays. Electrons at acceleration voltages of 180–225 kV reduced microbial loads of grains to <100 CFU/g. The viscosities of aqueous suspensions of grains treated with such low‐energy electrons were almost the same or higher than those irradiated with gamma‐rays at 0.1 kGy, much lower than necessary to disinfect grains. Results suggest that low‐energy electrons can decontaminate grains with little starch degradation compared to gamma‐rays.
Modeling Combined Effects of Temperature and pH on Heat Resistance of Spores by a Linear‐Bigelow Equation
Authors: MAFART P. , LEGUERINEL I.
Published: July 2006

A generalized linear‐Bigelow model was proposed to describe the effects of both temperature and pH on spore heat resistance. The model required only 3 parameters, each having a physicochemical significance. In addition to the conventional z value, the effect of pH on thermal resistance of spores was characterized by a zpH value. Although the model neglected interactions between temperature and pH, its goodness of fit and its robustness enable it to be applied for optimization of heat treatments. Further experiments need to be undertaken to validate the model under industrial conditions.
Rigor Contractions in “Rested” and “Partially Exercised” Chinook Salmon White Muscle as Affected by Temperature
Authors: JERRETT A.R , HOLLAND A.J. , CLEAVER S.E.
Published: July 2006

Time lapse video was used to determine the effects of temperature and fatigue on the development of rigor contractions in chinooksalmon (Oncorhynchus tshawytscha) white muscle. Minimal handling and chemical anaesthesia (AQUI‐STM) produced rested fish. After removal of one fillet from the rested fish, post‐mortem electrical stimulation of the carcass was used to partially exercise the remaining muscle. Specific strips of rested and partially exercised muscle were held in physiological saline at 0,4,6,8 and 12°C. Contraction onset and end were delayed by decreasing temperature in the rested treatment, but were unaffected in the partially exercised treatment. The final contracted length was affected by fatigue state and temperature.
Apparent Specific Heat of Chicken Breast Patties and their Constituent Proteins by Differential Scanning Calorimetry
Authors: MURPHY R.Y. , MARKS B.P. , MARCY J.A.
Published: July 2006

Chicken breast meat yielded three endothermic transitions, with peak transition temperatures of 53,70, and 79°C. Comparison with the purified protein fractions indicated that these transitions corresponded to denaturation of myofibrillar (53°C) and sarcoplasmic (70 and 79°C) proteins. The apparent specific heat profile of chicken breast meat was successfully modeled as a weighted average of the apparent specific heat of the constituent proteins. The specific heats of sarcoplasmic protein, myofibrillar protein, and chicken breast meat were strongly influenced by temperature; however, the specific heat of stromal protein was nearly constant across the temperature range considered (i.e., 10 to 100°C).