bluuebunny/crossref_metadata_2025_split 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

SummaryThe 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

SummaryCommercially 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

SummaryThe 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

SummaryThe 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

SummaryThe 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

SummarySeven 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

SummaryZein, 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

SummaryBasic 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

SummaryAfter 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

SummaryThe 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

SummaryAfter 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

SummaryBeef 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

SummaryThe 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

SummaryThe 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

SummaryPeanut 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

SummaryA 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

SummaryThe 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

SummaryThe 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

SummaryThis 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.