bluuebunny/crossref_metadata_2025 huggingface dataset:
A model food system for mass transfer in the acidification of cut root vegetables
Authors: AZEVEDO ISABEL C. A. , OLIVEIRA FERNANDA A. R.
Published: July 2010

The main objective of this work was to assess the adequacy of a 5% agarose gel to simulate the acetic acid acidification process in cut raw root vegetables. The process was well described by a Fickian model, and temperature dependence of diffusivity followed Arrhenius behaviour from 20 to 70°C with an activation energy of 16.8 kJ mol−1. Equilibrium conditions were described with a constant partition coefficient of 0.94. External resistance to mass transfer was measurable under stagnant conditions and the mass transfer coefficients also changed with temperature as in an Arrhenius type equation with activation energy of 17.8 kJ mol−1. Raw turnips and potatoes were acidified for comparison and the acid uptake followed a similar behaviour, although some differences in the parameters were observed. In general terms it was concluded that the 5% agarose gel is a suitable model food for studying acetic acid processing of raw root vegetables with exposed cut surfaces.
Growth of the psychrotrophic pathogens Aeromonas hydrophila, Listeria monocytogenes and Yersinia enterocolitica on smoked blue cod (Parapercis colias) packed under vacuum or carbon dioxide
Authors: BELL R. GRAHAM , PENNEY NICHOLASS , MOORHEAD SANDRA M.
Published: July 2010

Commercially prepared smoked blue cod (Parapercis colias) was divided into 25‐g subsamples which either served as uninoculated controls or were inoculated with a two‐strain cocktail of one of the psychrotrophic pathogens Aeromonas hydrophila, Listeria monocytogenes or Yersinia enterocolitica. The inoculated and control subsamples were then either vacuum or carbon dioxide packed prior to storage at 3°C or −1.5°C. After various periods of storage, triplicate samples from both packaging treatments for the three pathogens and the corresponding uninoculated controls were removed and subjected to microbiological analysis. None of the three pathogens was found as a natural contaminant of the commercial product. In vacuum‐packs all three psychrotrophic pathogens were able to grow during storage at 3°C. Reduction of the storage temperature to − 1.5°C retarded but did not prevent pathogen proliferation. Under carbon dioxide, only A. hydrophila was able to grow at 3°C and then only after a 21‐day lag period. None of the psychrotrophic pathogens was able to grow under carbon dioxide at − 1.5°C. With the possible exception of A. hydrophila, pathogen numbers did not decline in carbon dioxide packs during 155 days storage at − 1.5°C. It is concluded that provided gross contamination with psychrotrophic pathogens prior to packaging does not occur, a 100% carbon dioxide controlled atmosphere can be used to extend the product life of smoked blue cod during storage at or below 0°C without compromising its safety in respect to growth of A. hydrophila, L monocytogenes or Y. enterocolitica.
Use of Photobacterium leiognathi in studies of process equipment cleanability
Authors: WIRTANEN GUN , NISSINEN VESA , TIKKANEN LEENA , MATTILA‐SANDHOLM TIINA
Published: July 2010

The aim of the EC funded Project AIRI‐CT‐92 is to develop methods for the cleanability testing of food processing equipment. Photobacterium leiognathi ATCC 33469 has been suggested as an indicator organism in cleanability testing. Here, this bacterium was grown as a biofilm for 5 h or 24 h at room temperature on various surfaces, clean or milk‐soiled, by immersing the surfaces in luminous medium inoculated with P. leiognathi. The surfaces were then rinsed or cleaned using a CIP procedure before the hygienic status was determined using conventional plating, bioluminescence output and image analysis.

Rinsing did not eliminate the bacterium from the surfaces nor did the CIP procedure when 24‐h biofilms were used, as was readily seen after enrichment in luminous medium. In image analysis the biofilm showed a spotlike growth pattern which was most evident on stainless steel. The advantage of P. leiognathi in the cleanability assessment, which is based on the natural light output of the test bacterium, is that the test is easy to perform and can be carried out without use of expensive reagents.
Current methods to evaluate contribution and interactions of components to flavour of solid foods using hard cheese as an example
Authors: DELAHUNTY CONOR M. , PIGGOTT JOHN R.
Published: July 2010

The flavours of hard cheeses are derived from the balance of odourants and tastants released during their consumption, but the identity, and balance, of these flavour‐inducing compounds is still unknown for most cheeses. This can be attributed to the complexity of cheese composition and its analysis, of the processes occurring during consumption and the variations of human perception and expression of flavours. This review addresses some of the issues and methods being used to understand cheese flavour. It discusses factors which determine flavour release in the mouth, methods of preparation of extracts for analysis, sensory assessment of cheese flavour components and fractions, and of whole cheese, identification of odour active compounds and determination of their relative importance, temporal methods of analysis for flavour release and perception and methods of data analysis.
Ability of neonatal human Lactobacillus isolates to remove cholesterol from liquid media
Authors: MARSHALL VALERIE M. , TAYLOR ELIZABETH
Published: July 2010

The activity of a number of human intestinal strains of Lactobacillus acidophilus, including newly isolated neonatal strains, have been examined for their ability to remove cholesterol from liquid medium. In common with other authors we find that cholesterol will co‐precipitate with deconjugated bile acids as pH falls to values less than 5.0. But we also report that for some strains removal of cholesterol can occur in the absence of bile and that co‐precipitation at low pH values cannot account for all cholesterol removed. The activity is unlikely to be as a result of bacterial cholesterol oxidase or dehydrogenase but may be one of physical association with the bacterial cell surface.
Fatty acid composition of the total, neutral and phospholipids of pond‐raised Brazilian Piaractus mesopotamicus
Authors: MAIA EVERARDO LIMA , RODRIGUEZ‐AMAYA DELIA B. , HOTTA LUIZ K.
Published: July 2010

Seven sample lots of farmed Piaractus mesopotamicus, fed a set diet, collected at different times during the year were analysed. The total lipids (11 ± 3% fresh weight, muscle) consisted of 94% neutral lipids and 5% phospholipids. Sixty‐seven fatty acids and dimethylacetals were detected in the total lipids, the principal acids being 18:1ω9±ω7 (41.0 ± 1.7%), 16:0 (24.2 ± 1.2%), 18.2ω6 (9.1 ω 0.5%), 16:1ω7 (8.9 ± 0.7%), 18:0 (7.7 ± 0.5%) and 14:0 (3.2 ± 0.5%). The neutral lipids exhibited a similar profile. The phospholipids had a higher proportion of polyunsaturated fatty acids, the major components being 18:1ω6 (9.1 ± 0.7%) (17.5 ± 1.8%), 16:0 (16.7 ± 2.0%), 20:4ω6 (11.6 ± 1.3%), 22:6ω3 (11.0 ± 1.3%), 18:2ω6 (9.1 ± 0.7%), 18:0 (8.9 ± 1.1%), 22:5ω (5.8 ± 0.7%). No definite trend was seen in relation to season (water temperature, 7–26°C). The fish samples analysed were poor in ω3 fatty acids, which appeared to reflect the low ω3 fatty acid content of the diet.
Improved water resistance in edible zein films and composites for biodegradable food packaging
Authors: YAMADA KOHJI , TAKAHASHI HIDEKAZU , NOGUCHI AKINORI
Published: July 2010

Zein, corn prolamine, was dissolved in several organic solvents to make films and their properties were examined. Ethanol with 20% water and acetone with 30% water were found to dissolve zein well and transform it into a transparent flexible film after moderate drying. Both films showed similar breaking strength to that of commercial thin film of polyvinylidene chloride for food use and were digested with proteases. Only the film prepared from acetone solution showed a relatively low water permeability. This water permeation was found to depend strongly on the rate of diffusion. 1,2‐Epoxy‐3‐chloropropane (ECP) was added into the acetone solution to cross‐link the zein molecules for the purpose of improving the breaking strength and water‐resistant properties of the film. Alpha‐chymotrypsin was found to digest the film even after the modification with ECP. However, this cross‐linking resulted in little improvement in the water‐resistant properties of the film and also reduced its flexibility.
Mechanical strength and rheological behaviour of barley kernels
Authors: BARGALE PRAVEEN C. , IRUDAYARAJ JOSEPH
Published: July 2010

Basic mechanical and rheological properties (stress relaxation behaviour) of single barley kernels under uni‐axial compression were studied. The mechanical properties studied were the modulus of elasticity, yield and ultimate compressive strength, and the modulus of toughness as influenced by the moisture content. The stress relaxation experiments also included the effect of deformation rates and strain levels.

Results indicated that with an increase in moisture content, the strength of the barley kernels decreased while the energy required to cause rupture in the kernel increased initially and then decreased. The stress relaxation behaviour of barley kernels was described by a threeterm Maxwell model with a Maximum Relative Difference (MRD) ≤5%, when compared with one‐ and two‐term Maxwell models. The elastic component (E1) and relaxation time constant (τ1) of the first term of the three‐term Maxwell model decreased linearly with increase in moisture content. Of the different variables studied, moisture content had a significant influence on both of these parameters.
Rapid moisture and fat determination by pulsed NMR for monitoring drying and coating processes of extrudates
Authors: DAVENEL ARMEL , MARCHAL PHILIPPE
Published: July 2010

After extrusion cooking, extrudates must be dried and are often coated by spraying with fatty materials before cooling and packaging. As a means to control the drying and coating processes of pet foods, a rapid NMR method was developed to determine water and fat contents over a large temperature range without weighing, heating or measuring the temperature of the samples. Weighing was avoided by normalizing all NMR intensities by the solid echo maximum of each sample. Formulae using estimates of the transverse relaxation time and the concentration of liquid fat protons were used to determine total fat and moisture contents without measuring the temperature of the samples. Fat content estimation had a standard deviation better than 0.2% over a large solid fat index range above 20°C. Water content was determined with a standard deviation of about 0.2% at all temperatures studied.
The effect of ionising radiation on the CIELAB colour co‐ordinates of chicken breast meat as measured by different instruments
Authors: MILLAR SAMUEL J. , MOSS BRUCE W. , MACDOUGALL DOUGLAS B. , STEVENSON M. HILARY
Published: July 2010

The colour of irradiated and unirradiated chicken breasts was measured at two laboratories (A & B). The effect of instrumental differences on the CIELAB colour co‐ordinates and reflex attenuance spectra of the chicken breasts was examined. Each laboratory used two spectrophotometers, one of which was common to both. Laboratory B operated their other spectrophotometer in two different measuring geometries. Irradiated chicken breasts were found to exhibit increased a* values (greater redness) when compared with the unirradiated controls. Although differences in absolute CIELAB co‐ordinates were found between instruments, all the instruments evaluated indicated increased redness and chroma values for the irradiated samples. Examination of reflex attenuance spectra indicated that the increases in a* observed were due to lesser absorption of light in the 600–700 nm region, although evidence of a change in pigment form was limited.
Commentary on ‘Optimization of experimental parameters for the EPR detection of the cellulosic radical in irradiated foodstuffs’
Authors: DESROSIERS MARC , BENSEN DEBRA , YACZKO DEANNA
Published: July 2010

After many interlaboratory trials, several EPR methods for the detection of irradiated foods are being prepared as standard protocols. The works of Goodman et al. (1994) and Raffi et al. (1992) present conflicting general recommendations for optimum parameter sets in the EPR protocols. Here we demonstrate the shortcomings of recommending general parameter sets for the varying types of food samples and the different spectrometer configurations employed to examine them.
Continued inhibitory effect of carbon dioxide packaging on Listeria monocytogenes and other microorganisms on normal pH beef during abusive retail display
Authors: AVERY SHERYL M. , ROGERS ANDREA R. , BELL R. GRAHAM
Published: July 2010

Beef steaks of normal pH (5.3–5.5) were inoculated with Listeria monocytogenes, individually packaged in saturated carbon dioxide atmosphere packaging (SCAP) for <3 h or 5 or 8 weeks or in vacuum packaging (VP) for <3 h, and stored at −1.5°C. After each storage period, 27 individually packaged steaks were removed from their storage packs, overwrapped and placed on retail display under conditions simulating gross temperature abuse (12.25°C). Other steaks were removed from their storage packs and rinsed to remove L. monocytogenes cells, which were re‐inoculated onto freshly cut beef steaks to simulate cross‐contamination. These crosscontaminated steaks were overwrapped and also subjected to abusive display. Meat pH did not change significantly during storage or retail display. During the retail display of steaks previously stored in SCAP, the lag phase of aerobic bacteria and lactic acid bacteria was longer after prolonged storage compared to short (<3 h) exposure to carbon dioxide. For the same samples, L. monocytogenes failed to grow during retail display or grew only slightly after a prolonged lag phase (>75 h), even after only brief exposure time (<3 h) to carbon dioxide. In contrast, with cross‐contaminated steaks, when the inocula had been exposed to SCAP or VP for a short time (<3 h) the L. monocytogenes lag phase was shorter (<20 h). Inocula from steaks stored in SCAP for 5 or 8 weeks did not grow on the cross‐contaminated steaks. It is concluded that exposure of both the beef substrate and the L. monocytogenes inoculum to carbon dioxide during prolonged chilled storage does not increase the risk of growth of L. monocytogenes when that meat is subsequently placed on retail display, nor is there a large risk of growth of L. monocytogenes where cross‐contamination from SCAP stored raw beef to fresh raw beef occurs prior to retail display.
High pressure and pasteurization effect on duck foie gras
Authors: EL MOUEFFAK ABDELHAMID , CRUZ CHRISTIAN , ANTOINE MONIQUE , MONTURY MICHEL , DEMAZEAU GERARD , LARGETEAU ALAIN , ROY BERNADETTE , ZUBER FRANCOIS
Published: July 2010

The effects of combined high pressure (300 and 400 MPa) and low temperature (50°C) treatments on the microbial contamination of duck foie gras samples were compared with those of classical thermal pasteurization (85°C at the coldest point). A multilayer packaging film (PE/PA/PE) was selected from two films commonly used for these types of food, by preliminary tests showing its ability to limit microbiological development in such samples. In each experiment, microbiological contamination was analysed on treated and untreated samples, and results were systematically compared with those obtained from a classically pasteurized sample of the same liver. A pasteurization type effect (drastic reduction of vegetative mesophilic and psychrophilic contaminations, destruction of coliforms and of Staphylococcus aureus) was obtained at this temperature with samples pressurized at 400 MPa for at least 10 min.
Effect of irradiation and chilled storage on the microbiological and sensory quality of a ready meal
Authors: McATEER NICOLA J. , GRANT IRENE R. , PATTERSON MARGARET F. , STEVENSON M. HILARY , WEATHERUP S.T. COLIN
Published: July 2010

The sensory and microbiological quality of both non‐irradiated and irradiated cook‐chill ready meals consisting of roast beef and gravy, cauliflower and sauce together with roast and mashed potatoes were assessed at intervals during 15 d storage at 2–3°C.

Growth of Pseudomonas spp. caused obvious spoilage of the non‐irradiated meals after storage, whereas spoilage was not apparent in the irradiated meals. Irradiation (2 and 3 kGy) reduced the number of microorganisms in the meal to <100 g−1 initially and significant microbial growth did not occur during storage.

Using sensory profiling techniques a trained panel found that the effects of irradiation and chilled storage were most apparent in the cauliflower and potato components and occurred most often in the colour, appearance and textural attributes.

The combination of low dose irradiation and chilled storage effectively controlled microbial growth but changes in the sensory characteristics may limit the potential of irradiation to extend the shelf‐life and enhance the safety of this ready meal.
Effect of emulsifier type and homogenization temperature and pressure on physical properties of peanut extract
Authors: RUSTOM ISMAIL Y.S. , LÓPEZ‐LEIVAL MIGUEL H. , NAIR BABOO M.
Published: July 2010

Peanut extract (90.4% moisture, 3% protein and 4.5% fat, w/w) was homogenized using a two‐valve homogenizer and the effects of emulsifier and homogenization temperature and pressure on the physical properties were studied. Homogenization without emulsifier at 72°C increased the emulsion stability (ES) and sedimentation index (SI) by 5–11% and 15% respectively, compared to homogenization at 60°C. Homogenization with gum arabic increased the ES and viscosity by 17–22% and 127–176% respectively, and decreased SI by 26–38%. Homogenization with soya lecithin increased the ES and viscosity by 28–33% and 16–18% respectively, and decreased SI by 35–44%. Homogenization with Recodan EMS® (monodiglycerides + glycerol monostearates + soya lecithin) or Recodan CM® (monodiglycerides + glycerol monostearates + guar gum + carrageenan) increased the ES and colour lightness (L*) by 43–60% and 12% respectively, and decreased SI by 44–48%. Addition of Recodan CM® increased the viscosity by 482%. ES and L* increased with pressure. Extracts homogenized without emulsifier, with gum arabic, soya lecithin or Recodan EMS® were Newtonian whereas the extract homogenized with Recodan CM® was pseudoplastic.
Spectrophotometric determination of single synthetic food colour in soft drinks using ion‐pair formation and extraction
Authors: LAU OI‐WAH , POON MEGGY M.K. , MOK SIU‐CHEUNG , WONG FANNY M.Y. , LUK SHIU‐FAI
Published: July 2010

A simple spectrophotometric method has been developed for the determination of water‐soluble synthetic food colours in soft drinks involving ion‐pair formation with octadecyltrimethyl ammonium bromide at pH 5.6 and extraction of the ion‐pair into n‐butanol. The proposed method has been applied to determine amaranth, carmoisine, Green S, Orange G, Patent blue V, Ponceau 4R, Sunset yellow and tartrazine singly in soft drinks.

The optimum experimental conditions for the method were reported. The percent‐age extraction for all the colours except Green S under the optimum conditions ranged from 98 to 100. The precision of the proposed method was in the range 1–2.4% at the level of 8.0 μg ml−1 for the food colours.
Physical measurement of the quality of fresh scad (Trachurus trachurus) and rainbow trout (Oncorhynchus mykiss) during ice storage using the RT Freshmeter
Authors: VAZ‐PIRES PAULO , ARAÚJO ISABEL , KIRBY ROY M.
Published: July 2010

The RT Freshmeter was used to obtain a quality index of two Portuguese fish, scad (Trachurus trachurus) and farmed rainbow trout (Oncorhynchus mykiss). The curves obtained were comparable to those previously published using the GR Torrymeter. However variations were lower during the first phase of storage and it was observed that the curves could be divided into two distinct regions. The slope of the linear regression was higher during the first 5 days of storage, representing the first region of the curve, in both fish studied.

It is proposed that the two different rates of change of the quality index obtained with the meter reflect the two predominant spoilage mechanisms, enzymic and microbiological. The RT Freshmeter measurements are compared to organoleptic changes.

Preliminary results obtained with the RT Freshmeter on rainbow trout fillets without skin indicate that this instrument is not suitable for use with this product due to large variations and curve slopes close to zero.
Kinetics of sunflower oil contamination with polycyclic aromatic hydrocarbons from contaminated recycled low density polyethylene film
Authors: ŠCIMKO PETER , KHUNOVÁ VIERA , ŠCIMON PETER , HRUBÁ MIROSLAVA
Published: July 2010

The possibility of food contamination with polycyclic aromatic hydrocarbons (PAHs) by rediffusion from polyethylene film made of contaminated recycled polyethylene (PE) was tested. PE was contaminated with PAHs by diffusion from water medium spiked with fluoranthene (FI), pyrene (Py), and benzo(a)pyrene (BaP). The PE was recycled by heating at 150°C for 10 min. The recycling process did not affect the PAH concentration in PE. From the recycled PE, a PE film was made and rediffusion of PAHs from the PE film into a sunflower oil was followed for 600 h at 24°C. Diffusion of PAHs into the oil demonstrated the potential of PAH‐contaminated PE as a source of contamination of food. The PAH concentration in vegetable oil was linearly dependent on the square root of the storage time. A kinetic equation for PAH rediffusion from PE film into the oil is proposed.
Studies on the electrostatic interactions of lysozyme with α‐lactalbumin and β‐lactoglobulin
Authors: HOWELL NAZLIN K. , YEBOAH NANA A. , LEWIS DAVID F.V.
Published: July 2010

This paper reports the occurrence of protein‐protein co‐precipitation, through electrostatic interactions. As a preliminary overview the effect of mixing lysozyme with a range of proteins (BSA, β‐lactoglobulin, sodium caseinate and whey isolate) was tested by turbidity measurements. Turbidity increased when the proteins were mixed with lysozyme in water and not in phosphate buffer. The exception was the interaction of whey isolate and sodium caseinate which showed turbidity (but not precipitation) when mixed with lysozyme in phosphate buffer. Further detailed studies on the interaction between whey proteins α‐lactalbumin and β‐lactoglobulin and hen egg lysozyme by fast protein liquid chromatography (FPLC), have shown that, in aqueous solution of pH 6.8, a higher level of interaction occurred between lysozyme and β‐lactoglobulin compared with lysozyme and α‐lactalbumin. A similar interaction was not observed between α‐lactalbumin and β‐lactoglobulin. The predominant product of the interaction was an insoluble precipitate. In addition, a small amount of soluble complex was also recovered by ion‐exchange chromatography of the supernatant. The soluble complex was shown by SDS‐polyacrylamide gel electrophoresis to comprise the same components as the insoluble precipitate, i.e. lysozyme and α‐lactalbumin or lysozyme and β‐lactoglobulin. The interactions of the proteins and the amount of precipitation varied depending on the concentration of each protein in the mixture, the ionic strength and pH of the solution. Molecular modelling studies, using interactive docking of the crystal structures, indicated that for the β‐lactoglobulin‐lysozyme interaction the optimum visual fit could involve electrostatic interactions between Glutamate 35 and Aspartate 53 in the catalytic binding site on lysozyme and Lysines 138 and 141 at the dimerization site of β‐lactoglobulin. For α‐lactalbuminlysozyme mixtures, however, the modelling suggested that non‐specific electrostatic binding may occur.
Perceived texture: direct and indirect methods for use in product development
Authors: JACK FRANCES R. , PATERSON ALISTAIR , PIGGOTT JOHN R.
Published: July 2010

Increasing consumer interest in texture has made it of primary concern in product development, since manipulating texture can provide product differentiation. Successful development requires both comprehensive understanding of texture as perceived by the consumer, and appropriate measurement methods. Perceived texture results from an array of sensory inputs, arising before and during consumption. Sensory analysis methods provide means to express such percepts, but can be time‐consuming and expensive. There are relationships between physiological parameters measured in individuals during food consumption, and perceived texture. Such measures can provide simple and rapid indices of texture, if validated before use, as routine tools in product development applications.
Effect of ultrafiltration on concentrated apple juice colour and turbidity
Authors: CONSTENLA DIANA T. , LOZANO JORGE E.
Published: July 2010

Colour and turbidity of conventional bentonite‐gelatin clarified apple juice was compared with 30,000–50,000 and 100,000DA hollow fibre ultrafiltered apple juice, with and without pectinolytic enzyme treatment. Results indicated that objective quality of ultrafiltered apple juice compared favourably with conventionally clarified apple juice over 30 weeks of storage at 37.5°C. However, treatment with pectinolytic enzymes before ultrafiltration increased both the initial colour and the browning rate. No significant differences were found in the values of the transmission haze after storage.
Effect of cooking on nitrate in dehydrated soups
Authors: GARCIA‐MATA MERCEDES , BOSCH‐BOSCH NIEVES , PEREZ‐RODRIGUEZ M. LUISA
Published: July 2010

Nitrate levels in dry powder soups were measured before and after cooking by a modified cadmium‐Griess method. In 36 different kinds of soups, from three manufacturers, no nitrate was lost on cooking in accordance with the manufacturers’ directions, even when simmered for up to 25 min.
Yield and storage stability of patties from pre‐rigor beef previously dipped in potassium sorbate and ginger solutions
Authors: NEGBENEBOR C. , BALAMI Y. , IGENE J.
Published: July 2010

Pre‐rigor beef strips dipped for up to 3 min in solutions of 2% ginger, 4% potassium sorbate or both were minced and made into patties. Meat yield before frying did not increase, but after frying the cooked pattie yield did increase with the mixed treatment. Yield increase was greatest with microwave cooking. There were no significant effects on pH, free fatty acids or TBA values, but slightly reduced total aerobic plate counts with the sorbate treatments when patties were stored at 5–7°C.
Effects of sporulation media and strain on thermal resistance of Bacillus cereus spores
Authors: MAZAS MARGARITA , GONZÁLEZ ISAAC , LÓPEZ MERCEDES , GONZÁLEZ JOSEFA , SARMIENTO ROBERTO MARTÍN
Published: July 2010

Spores of Bacillus cereus strains ATCC 7004, ATCC 4342 and ATCC 9818 were produced in four sporulation media (Nutrient Agar supplemented with 1 ppm Mn2+, Fortified Nutrient Agar, Angelotti Medium and Milk Agar) and their percentages of sporulation and heat resistance parameters obtained in a wide temperature range were compared. In all conditions studied, high rates of sporulation were obtained. Clear differences among D‐values for spores produced in the four media were observed. the medium which yielded the most resistant spores and the magnitude with which the sporulation medium affected D‐values was different for each strain. z‐Values of the three strains were not influenced by the medium used to obtain spores.
Original article: The effect of freezing at −18 °C and −70 °C with and without ascorbic acid on the stability of antioxidant in extracts of apple and orange fruits
Authors: Polinati Renata Madureira , Faller Ana Luísa Kremer , Fialho Eliane
Published: July 2010

The influence of low temperature and storage time on the antioxidant capacity of standard solutions and apple and orange extracts was evaluated. In addition, the effects of ascorbic acid (AA) addition to the fruit extracts in terms of antioxidant capacity, AA content and soluble and hydrolyzable polyphenol contents were also analysed. Polyphenol contents in both apple and orange extracts were stable during storage period, which reflected also in the antioxidant capacity stability. Freezing at −18 °C did not result in different retention rates for polyphenols, AA and antioxidant capacity when compared to freezing at −70 °C. However, vitamin C content in orange juice, without AA addition, slightly increased along the experimental period (10 days). Thus, this study shows that it may not be necessary to measure the antioxidant capacity immediately after the preparation of fruit extracts or antioxidant standard solutions.
Original article: Thermal and light degradation kinetics of anthocyanin extracts from mangosteen peel (Garcinia mangostana L.)
Authors: Chisté Renan C. , Lopes Alessandra S. , De Faria Lênio J. G.
Published: July 2010

The stability and half‐life time of anthocyanin extracts from mangosteen peel were studied under controlled oxygen supply, undergoing the influence of light source (fluorescent, incandescent, infrared and ultraviolet) and storage temperature (5, 28, 40 and 50 °C). The kinetic parameters for anthocyanin degradation, under different illumination conditions fit the first‐order reaction model, and the exposition under fluorescent light resulted in a higher half‐life time (597 h), followed by incandescent (306 h), ultraviolet (177 h) and infrared (100 h). The kinetic behaviour for the storage in different temperatures also fit the first order, and at 5 °C the highest half‐life time (4006 h) was found, followed by 28 °C (370 h), 40 °C (125 h) and 50 °C (93 h). The activation energy was 14.7 Kcal.mol−1, and Q10 values showed that at 5 °C the anthocyanin extracts were more sensitive to storage temperature changes compared to the other tested temperatures.
Genetic differences in the elevational limits of native and introduced Lactuca serriola populations
Authors: Alexander Jake M.
Published: July 2010

Aim  Differences in phenological timing might explain why populations of the annual Lactuca serriola reach higher elevational limits in a part of its introduced range than in its native range. I investigated (1) whether this difference in elevational limits has a genetic basis, (2) the importance of clinal genetic differentiation and phenotypic plasticity in phenology as responses to elevation in L. serriola, and whether these responses differ between regions, and (3) whether the realized temperature niche of L. serriola differs between the two regions.

Location  Plant material was collected in Canton Valais, Switzerland (native range) and the Wallowa Mountains, Oregon, USA (introduced range). The field experiment was conducted in Canton Grisons, Switzerland.

Methods  Plants from 20 populations collected along elevational gradients were grown in eight common gardens established at 200‐m elevational intervals (600–2000 m a.s.l.). The timing of phenological transitions was monitored and analysed with mixed‐effects models to determine differences in (1) elevational limits, and (2) clinal genetic differentiation and phenotypic plasticity as responses to elevation for plants from each region. The limits of the species along five temperature gradients were derived from generalized linear models using published occurrence data to quantify regional differences in the realized temperature niche.

Results  The limit of seed set (1400 m a.s.l.) was the same for plants of both regions. However, the limit of flowering, probably a better reflection of elevational limits in this study, was 400 m higher for plants from the introduced region due to their faster development. Native populations showed clines in development time with elevation consistent with expectations. However, these were weaker in introduced populations, the responses of which were rather characterized by phenotypic plasticity. Thus, although introduced populations grow at considerably cooler sites than in the native region, this is unlikely to have resulted from direct selection for tolerance of high‐elevation conditions.

Main conclusions  This study supports a genetic basis for differences in the elevational limits of L. serriola populations between two parts of its native and introduced range. Although it is not yet clear whether these differences evolved in the introduced range, these findings highlight the potential of alien species for gaining insights into niche evolution.
High biogeographical and evolutionary value of Canary Island pine populations out of the elevational pine belt: the case of a relict coastal population
Authors: López de Heredia Unai , Venturas Martin , López Rosa Ana , Gil Luis
Published: July 2010

Aim  Marginal populations are frequently neglected in static views of vegetation types, particularly when defining conservation reserves. The biogeographical and evolutionary importance of a marginal and endangered population of Pinus canariensis is addressed in this study to ascertain the need for conservation action. Diversity loss between adults and offspring and patterns of seed dispersal and recruitment were examined to provide evidence of recent degradation of marginal P. canariensis pinewoods. The scientific basis for the provision of sound conservation policies was investigated by elucidating the factors responsible for significant population structure.

Location  An isolated low‐density pinewood community confined to the Arguineguin ravine, in south Gran Canaria, Canary Islands.

Methods  Two cohorts, of centenary trees (those older than 100 years) and young recruits, respectively, were found in a detailed inventory of the pine population in the Arguienguin ravine. Chloroplast and nuclear microsatellites were compared to assess the levels of genetic diversity between adults and recruits. Spatial genetic structure and parentage analysis based on highly polymorphic nuclear and chloroplast microsatellites were examined to test limitations in seed dispersal. The underlying environmental factors that led to a clustering effect in the population were tested using point pattern methodologies.

Results  Centenary trees retain high levels of genetic diversity and effective population size, suggesting a wider extension of the pinewood forests in the past. A significant loss of genetic diversity was detected between adults and recruits. Pinus canariensis dispersal distances were among the longest ever reported for anemochorous species, suggesting that environmental factors account for recruit clustering. Cluster models showed that recruits tend to aggregate in dry streambeds, where soil and water accumulation favours establishment.

Main conclusions  Boundary populations of P. canariensis are subjected to fragmentation and reduction in effective population size as a result of human impact. Marginal populations were denser in the past and currently require specific conservation efforts. A severe reduction in genetic diversity compromises the future of present populations. Streambeds appear to play a major role in recruit establishment, but data suggest the absence of limitations to seed dispersal.
Community development along a proglacial chronosequence: are above‐ground and below‐ground community structure controlled more by biotic than abiotic factors?
Authors: Carlson Matthew L. , Flagstad Lindsey A. , Gillet François , Mitchell Edward A. D.
Published: July 2010

1. We studied vascular plant and soil‐dwelling testate amoeba communities in deglaciated sites across a range of substrate ages in Kenai Fjords, Alaska, USA to test four hypotheses. (i) Patterns of community assembly are similar for vascular plants and testate amoebae. (ii) Vascular plant and testate amoeba communities are more strongly correlated to abiotic variables than to each other, since these communities are not directly linked trophically. (iii) Plant community structure becomes less associated with abiotic condition in succession relative to testate amoebae, as species replacement is believed to be more common for plants than testate amoebae. (iv) Above‐ and below‐ground communities become more strongly linked over the succession, due a shift from predominantly allogenic to autogenic forces.

2. We assessed relationships among biotic communities and abiotic site variables across the chronosequence using multiple factor analysis, redundancy analysis (RDA) and a moving‐window analysis.

3. The diversity patterns and the communities’ response to site and soil variables differed between groups. The composition of both communities was significantly explained by bedrock type and moisture regime. The vascular plant community, however, was more influenced by distance from the glacier.

4. Testate amoeba and vascular plant community patterns were significantly linked to each other and to location and physical conditions. The moving‐window RDA indicates the variation explained by the physical and chemical environment tended to slightly decrease through the chronosequence for testate amoebae, while a bell‐shape response was evidenced for vascular plants. The variation of the microbial community explained by the plant community was very low in the early stages of the succession and became higher than the variation explained by the environmental variables later in the chronosequence.

5. Synthesis. These results suggest that vascular plants and testate amoebae are as linked or more in ecosystem development than either community is to changes in site condition. Furthermore, the strength of interactions varies along the succession. Thus, ecological links may be more important than macro‐scale abiotic site condition is to community development, even between communities without direct trophic interactions.
Contrasting effects of cattle and wildlife on the vegetation development of a savanna landscape mosaic
Authors: Veblen Kari E. , Young Truman P.
Published: July 2010

1. Through their effects on plant communities, herbivores can exert strong direct and indirect effects on savanna ecosystems and have the potential to create and maintain savanna landscape heterogeneity. Throughout much of sub‐Saharan Africa, periodic creation and abandonment of livestock corrals leads to landscape mosaics of long‐term ecosystem hotspots that attract both cattle and large ungulate wildlife.

2. The development and maintenance of vegetation in these types of hotspots may be controlled in part by herbivory. Cattle and wildlife may have different, potentially contrasting effects on plant succession and plant–plant interactions. We ask how cattle and wild herbivores affect the maintenance and vegetation development of corral‐derived landscape heterogeneity (0.25–1.0 ha treeless ‘glades’) in Laikipia, Kenya, through their effects on long‐term successional and short‐term plant–plant dynamics.

3. We used the Kenya Long‐term Exclosure Experiment to exclude from glades different combinations of cattle, large ungulate wildlife (i.e. zebras, gazelles and other antelopes), and mega‐herbivore wildlife (i.e. giraffes and elephants). We first assessed long‐term changes in cover of the dominant grass species, Cynodon plectostachyus and Pennisetum stramineum (the early‐ and late‐dominant species, respectively). We then used a neighbour removal experiment to test the effects of different herbivores on competition and facilitation between the two glade grass species.

4. In the long‐term experiment, we found that large ungulate wildlife reinforced landscape heterogeneity over time by helping maintain glades in their early C. plectostachyus‐dominated form. Cattle and mega‐herbivore wildlife, on the other hand, appeared to reduce the positive effects through forage preference for C. plectostachyus.

5. In the neighbour removal experiment, we found that each grass species benefited from facilitation when it was the preferred forage for the dominant grazer. Facilitation of C. plectostachyus by P. stramineum was strongest when cattle co‐occurred with wildlife, whereas facilitation of P. stramineum by C. plectostachyus was strongest when cattle were absent.

6. Synthesis. Our results demonstrate that different combinations of cattle and wildlife have different effects, largely via contrasting forage preferences, on the persistence of landscape heterogeneity in this savanna landscape. More generally, we provide evidence for contrasting effects of cattle and wildlife on short‐term plant interactions (facilitation) and successional processes within the herbaceous plant community.
Undercarboxylated matrix Gla protein is associated with indices of heart failure and mortality in symptomatic aortic stenosis
Authors: Ueland T. , Gullestad L. , Dahl C. P. , Aukrust P. , Aakhus S. , Solberg O. G. , Vermeer C. , Schurgers L. J.
Published: July 2010

Abstract.  Ueland T, Gullestad L, Dahl CP, Aukrust P, Aakhus S, Solberg OG, Vermeer C, Schurgers LJ (Research Institute for Internal Medicine, University of Oslo, Oslo; University of Oslo, Oslo, Norway; and VitaK & Cardiovascular Research Institute CARIM (CV, LS), Maastricht University, Maastricht, The Netherlands) Undercarboxylated matrix Gla protein is associated with indices of heart failure and mortality in symptomatic aortic stenosis. J Intern Med 2010; 268: 483–492.

Objective.  Matrix Gla protein (MGP) is a calcification inhibitor and alterations in circulating MGP have been observed in different populations characterized by vascular calcification. We hypothesized that patients with calcific valvular aortic stenosis (AS) would have dysregulated circulating MGP levels.

Design and subjects.  We examined plasma levels of nonphosphorylated carboxylated and undercarboxylated MGP (dp‐cMGP and dp‐ucMGP, respectively) in 147 patients with symptomatic severe AS and in matched healthy controls.

Main outcome measures.  We further investigated the relationship between MGP levels and aortic pressure gradients and valve area by echocardiography and measures of heart failure. Finally, we assessed the prognostic value of elevated plasma dp‐ucMGP level in relation to all‐cause mortality in patients with AS.

Results.  We found markedly enhanced plasma levels of dp‐cMGP and in particular of dp‐ucMGP in patients with symptomatic AS. Although only weak correlations were found with the degree of AS, circulating dp‐ucMGP was associated with cardiac function and long‐term mortality in multivariate analysis.

Conclusions.  A dysregulated MGP system may have a role in the development of left ventricular dysfunction in patients with symptomatic AS.
Operational lessons from 20 years of the Mectizan Donation Program for the control of onchocerciasis
Authors: Thylefors B. , Alleman M. M. , Twum‐Danso N. A. Y.
Published: July 2010

The donation of ivermectin (Mectizan®, Merck & Co., Inc.) to control onchocerciasis (river blindness) was established in 1987 and has since gradually expanded to provide for >570 million treatments cumulatively over the past 20 years. The Mectizan Donation Program (MDP) operates within a broad partnership in 33 endemic countries in need of mass treatment. Particular operational methods and tools are applied to facilitate ivermectin mass treatment. Drug management has been streamlined, including dosing, tablet size and packaging, and monitoring for adverse events. Much of the experience gained in the development of ivermectin mass treatment can be usefully applied in the recent broader perspective of control of neglected tropical diseases. The most important operational lessons of the MDP include: (i) the need to easily define the target population for treatment using rapid, non‐invasive techniques; (ii) the value of a broad partnership; (iii) the great potential of working through community‐directed treatment; (iv) the need to streamline all drug management aspects and (v) the importance of operations research to tackle new challenges.
Ultrasound and Endocrine Findings that Help to Assess the Risk of Late Embryo/Early Foetal Loss by Non‐Infectious Cause in Dairy Cattle
Authors: López‐Gatius F , García‐Ispierto I
Published: July 2010

Contents

This report reviews the clinical applications of routine ultrasound in gestation control programmes for dairy herds. Emphasis is placed on identifying risks of late embryo/early foetal loss of non‐infectious cause by monitoring ovarian structures (as opposed to uterine contents), indicators of pregnancy loss and twin pregnancies. Suggestions are provided to appropriately manage a cow at risk of pregnancy loss during the late embryonic/early foetal period. This review identifies gaps in our current knowledge of the aetiology of pregnancy loss and spontaneous embryo/corpus luteum reduction. Two areas of the implantation–placentation window of gestation in particular need urgent attention: the roles in pregnancy loss of immune–endocrine interactions and the physiological status of the embryo/corpus luteum. The latter issue and consecutively endocrine interactions could be successfully addressed by incorporating Doppler ultrasonography into routine ultrasound procedures.
Nutritional and Metabolic Mechanisms in the Ovary and Their Role in Mediating the Effects of Diet on Folliculogenesis: A Perspective
Authors: Scaramuzzi RJ , Brown HM , Dupont J
Published: July 2010

Contents

Folliculogenesis in ruminants is a nutritionally sensitive process, and short‐term increases in nutrient flux can stimulate folliculogenesis in sheep and cattle. These short‐term effects are probably mediated directly at the follicular level to modify gonadotrophin‐induced follicle growth and development. The follicle appears to have a number of ‘nutrient sensing’ mechanism that may form the link between nutrient status and folliculogenesis. This review examines the evidence for the presence of pathways that may sense nutrient flux from within the follicle including the insulin signalling pathway, adenosine monophosphate‐activated kinase (AMPK), the hexosamine pathway, peroxisome proliferator‐activated receptors (PPARs) and leptin. The review then assesses the available evidence concerning their mechanisms in the follicle and speculates on how these ‘nutrient sensing’ pathways are integrated into the FSH signalling pathways to adjust gonadotrophin‐stimulated follicular function. We conclude that there is good evidence to suggest that the follicle does contain more than one functional ‘nutrient sensing’ pathway that have intra‐follicular effects on some FSH‐mediated functions such as the synthesis of oestradiol, in granulosa cells. These pathways include insulin, AMPK, and leptin. There is also a good case for the integration of PPARs in the intra‐follicular sensing of nutrient flux. However, there is little evidence at present to suggest the hexosamine biosynthetic pathway has functional significance in the follicle as a sensor of nutrient flux. Further study will be required to fully understand ‘nutrient sensing’ pathways in the follicle and their cross‐talk with FSH signalling pathways.
Development of the embryo, larva and early juvenile of Nile tilapia Oreochromis niloticus (Pisces: Cichlidae). Developmental staging system
Authors: Fujimura Koji , Okada Norihiro
Published: July 2010

We described the developmental stages for the embryonic, larval and early juvenile periods of Nile tilapia Oreochromis niloticus to elucidate sequential events of craniofacial development. Craniofacial development of cichlids, especially differentiation and morphogenesis of the pharyngeal skeleton, progresses until about 30 days postfertilization (dpf). Because there is no comprehensive report describing the sequential processes of craniofacial development up to 30 dpf, we newly defined 32 stages using a numbered staging system. For embryonic development, we defined 18 stages (stages 1–18), which were grouped into seven periods named the zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatching periods. For larval development, we defined seven stages (stages 19–25), which were grouped into two periods, early larval and late larval. For juvenile development until 30 dpf, we defined seven stages (stages 26–32) in the early juvenile period. This developmental staging system for Nile tilapia O. niloticus will benefit researchers investigating skeletogenesis throughout tilapia ontogeny and will also facilitate comparative evolutionary developmental biology studies of haplochromine cichlids, which comprise the species flocks of Lakes Malawi and Victoria.