bluuebunny/crossref_metadata_2025 huggingface dataset:
Silage from tropical fish 1. Proteolysis
Authors: HALL G. M. , KEEBLE D. , LEDWARD D. A. , LAWRIE R. A.
Published: July 2010

Acid silages were prepared from silverbelly (Leiognathus sp.) at 30°C with 3% (w/w) of 98% formic acid. After 14 days, total protein solubilization was 45‐50%, of which 80% was TCA soluble and collagen solubilization was 42%. Centrifugation of 14 day old silage gave a cystine‐rich undigested sediment and a liquor with a low tryptophan content. Gel chromatography of the liquor of a 14 day old silage showed it to be composed of at least two fractions: one consisting of protein fragments of molecular weight greater than 5000 daltons and the other of free amino acids and small peptides. Soluble collagen breakdown products were found predominantly (75%) in the high molecular weight fraction. A mechanism for the solubilization of collagen by the action of acid pH, elevated temperature and non‐specific proteases is proposed. The limited autolysis in silverbelly silage is compared with that found in cold water fish silages and attributed principally to the resistance of warm water fish collagen to the effects of acid pH and temperature during ensilation.
Silage from tropical fish 2. Undigested fraction
Authors: HALL G. M. , LEDWARD D. A. , LAWRIE R. A.
Published: July 2010

The solubility of the undigested fraction (sediment) of a silage made from silverbelly (Leiognathus sp.) in sodium dodecyl sulphate, guanidine hydrochloride and 2‐mercaptoethanol, alone and in combination was evaluated. The sediment was probably composed of muscle proteins cross linked by disulphide bonds and stabilized by hydrophobic associations and hydrogen bonds. Ensilation followed by in vitro digestion of the sediment with pepsin/pancreatin/trypsin or in vivo digestion of the sediment using chicks, solubilized about 81% and 90% respectively of total nitrogen in silages up to 14 days old. The most resistant fraction was rich in collagenous derived material and bones. It is suggested that controlled ensilation can produce a highly digestible protein source without the formation of large amounts of reactive and labile free amino acids.
Utilization of Fick's second law for the evaluation of diffusion coefficients in food processes controlled by internal diffusion
Authors: AGUERRE R. J. , GABITTO J. F. , CHIRIFE J.
Published: July 2010

Several processes in the food industry, such as leaching and drying are usually controlled by internal diffusion. In many cases these processes have been interpreted on the basis of constant diffusion coefficients calculated through a series solution of Fick's second law which converge rapidly for large values of time. This work presents a numerical solution of Fick's second law for various types of concentration dependence of the diffusion coefficient. The results indicate that the above mentioned conventional treatment of experimental data, may not be sufficient to establish whether or not the process is characterized by a constant or variable diffusion coefficient.
Fire and explosion hazards in the spray drying of milk
Authors: BEEVER P. F.
Published: July 2010

Recent reports in the literature indicate that incidents involving fires and explosions in the spray drying of milk products are increasing in number. Whilst milk powder is not highly explosible, the conditions for a dust explosion, apart from the ignition source are almost always present in certain areas of a spray dryer during its normal operation. Self‐ignition of deposits is known to be possible at the high temperatures in a spray dryer. At best, this can cause product degradation and discolouration whilst at worst it can provide the source of ignition for an explosion. This paper is an attempt to draw together recent work on fire and explosion prevention and protection formilk powders.
Aflatoxins in imported edible nuts: some data 1982–84
Authors: KERSHAW S. J.
Published: July 2010

Results of 188 analyses for aflatoxin in edible nuts imported into the U.K. during 1982–84 are presented. Most samples (140/188, 74%) had aflatoxin B1, content ≤ 5 μg/kg. Brazilian peanuts may be identified as consistently unreliable as regards aflatoxin contamination.
Computer aided design in the food processing industry I. overview of process flowsheeting
Authors: PETERSEN J. N. , DROWN D. C.
Published: July 2010

A review of process flowsheeting as applied to the food processing industry is pre‐sented. Included is a history of process flowsheeting, an introduction to how this tool is ued by the process engineer, limitations of the tool in the food processing industry, a discussion of ongoing research relating to process flowsheeting, and a discussion of research needs in order to make this tool applicable to the food processing industry.
Computer aided design in the food processing industry.2. Applications of process flowsheeting
Authors: DROWN D. C. , PETERSEN J. N.
Published: July 2010

Applications of the GEMS computer flowsheet simulatian program to identify and evaluate cost saving opportunities in the food processing industry are described. Examples include modificatian af existing peel‐oil recavcry during orange juice processing, energy reduction and sugar control in patato blanching, and design improvements in process equipment for cross flow air tunnel dryers.
Gas chromatographic study of sorption of vinylchloride by unplasticized polyvinylchloride: Effect of concentration, temperature and polymer particle size
Authors: DEMERTZIS P. , KONTOMINAS M. G. , VOUDOURIS E. K.
Published: July 2010

The interaction of vinylchloride monomer with unplasticized polyvinylchloride is studied by inverse gas chromatography. The effect of monomer concentration, tem‐perature and polymer particle size are particularly examined. The specific retention volume (V°g) of VCM was taken as the parameter of the PVCNCM interaction and was found to be dependent upon monomer concentration, polymer particle size and temperature. V°g increased exponentially at very low monomer concentrations, in‐creased with decreasing resin particle size and decreased with increasing temperature. For a given resin particle size the effect of temperature on V°g is a lot more pronounced than the effect of particle size for a given temperature.

Values for thermodynamic parameters calculated and peak shapes recorded are indicative of an exothermic, spontaneous interaction between PVCNCM, and support the ‘active site’ hypothesis which limits potential migration of the monomer from the polymer into a food contacting phase.
Composition of flesh from different edible parts of cod
Authors: MCLAY R.
Published: July 2010

Cod fillet, trimmings from the fillet, and tissue recovered from the skeleton after filleting were assayed over a 12 month period for nitrogen, moisture, hydroxyproline and water holding capacity. No significant differences were found in nitrogen or moisture content. However, the mean hydroxyproline contents were significantly different in all three tissues. Water holding capacity was significantly less in tissues recovered from the skeleton than in fillet or fillet trimmings. A seasonal trend was observed in moisture and nitrogen content. Soluble and myofibrillar protein nitrogen and non‐protein nitrogen were also measured on the three tissue types. No significant differences were found.
Studies of the iced storage characteristics and composition of a variety of Bolivian freshwater fish. 1. Altiplano fish
Authors: POULTER N. H. , NICOLAIDES LINDA
Published: July 2010

The iced storage characteristics of three Bolivian freshwater fish species from the Altiplano region were monitored using chemical, microbiological and sensorial methods. Fish studied were: pejerrey (Busilichthys bonariensis) captured in two locations, Lake Poopo and Lake Angostura; trout (Sulmo gairdneri) from Lake Titi‐caca and carp (Cyprinus carpio) from Lake Angostura. The proximate composition and physical nature of these fish are presented. The shelf lives of these species, as deter‐mined by both sensory and microbiological evaluations, were found to be: pejerrey from Lake Poopo: 20–21 days, pejerrey from Lake Angostura: 15‐19 days, carp from Lake Angostura 17–20 days and trout from Lake Titicaca: 15–18 days. The value of the various methods used to monitor quality changes are discussed.
Effect of seed coat thickness and blanching on the water absorption by soybeans
Authors: KING R. D. , ASHTON S. J.
Published: July 2010

Water absorption by whole soybeans and by soybeans with their seed coat partially abraded was compared. The rate of absorption by the whole seeds was less than that for the abraded seeds. The effect of blanching on the rate of water absorption and absorption capacity in whole soybeans and in beans with their moisture content adjusted by storage to 33 and 65% ERH was examined. Blanching the seeds resulted in an increase in the rate of absorption but reduced the absorption capacity of the beans. The samples with the higher water activity showed the largest increase.
Simulated transit studies on tomatoes; effects of compressive load, container, vibration and maturity on mechanical damage
Authors: OLORUNDA A. O. , TUNG M. A.
Published: July 2010

The compressive force‐deformation characteristics of tomatoes in the green, turning and red stages were determined with a view to obtaining information on the rupture force for these fruits. This was followed by a simulated transit study which investigated the effects of vibration, compressive load and type of container on mechanically induced damage, using a fractional factorial experimental design. The force‐deformation studies showed that ripening leads to a significant decrease in tomato bioyield point, toughness and firmness and an increase in compliance. In the simulated transit study, mechanical damage was significantly affected by the stage of tomato maturity, container type, vibration and compressive load. It was found that the appli‐cation of uniform moderate pressure on the produce during transportation would reduce the incidence of impact damage. The implications of these findings in the design and general improvement of packaging containers used for conveying perishable agri‐cultural produce in developing countries are discussed.
Supplementation of fermented sorghum Kisra bread with legume protein isolates
Authors: TINAYSP A. H. EL , MAHDI Z. M. EL , SOUBKI A. EL
Published: July 2010

Kisra is a fermented sorghum flour bread which constitutes the staple diet in Sudan. Sorghum, like other cereals, has some limitations due both to its low protein content and to limitations in some essential amino acids particularly lysine. The objective of the present work was to increase the protein content of Kisra and improve the amino acid profile, especially lysine. Protein isolates were prepared from bonavist bean and white bean by alkaline extraction. The protein isolates were used to increase the protein content of the fermented sorghum dough to about 25%. The legume protein isolate supplemented dough was fermented in the traditional method used for making Kisra. The most significant effect of Kisra supplementation was the improvement in protein content (two‐fold) as well as the increase in the limiting amino acids. The results indicated a significant increase (P < 0.01) in lysine in the protein supplemented doughs and Kisras as compared to the control. The increase in lysine ranged 2–2.6 folds. Sorghum supplementation with legume protein isolates was not accompanied by signifi‐ cant changes in organoleptic properties of the end product.
Pickling of dates at the early khalal stage
Authors: YOUSIF A. K. , HAMAD A. M. , MIRANDILLA W. A.
Published: July 2010

The possibility of pickling dates at the khalal stage was investigated. The effect of boiling, lye treatment, cutting and brine solution were studied. The results of this preliminary study suggest that a good date pickle could be obtained using a brine solution of 40 salometer and adding acetic acid. Cutting and lye treatment of fruits were not necessary, while boiling of fruits for 5 min was helpful to produce an acceptable product.
Effect of freezing rate on the denaturation of myofibrillar proteins
Authors: WAGNER J. R. , AÑON M. C.
Published: July 2010

Freezing of bovine muscle has a denaturating effect on myofibrillar proteins, Differ‐ential Scanning Calorimetry (DSC) studies of fresh and frozen muscle at different freezing rates show a decrease on denaturation enthalpies; the lower the freezing rate the greater the loss. When measuring the specific areas (ratio between each partial area in cm', and the dry weight of the sample, in mg) of the DSC thermograms, it can be observed that the area ascribed to myosin decreases with freezing, while the area corresponding to actin is not affected. These results are in agreement with the ATPase activity decreases as a consequence of freezing observing higher losses at lower freezing rates. The denaturation observed could be a result of a partial unfolding of the myosin head being more pronounced at low freezing rate.
Protein digestibility of pigskin and bovine tendon in rats
Authors: REUTERSWÄRD Anita Laser , ASP N.‐G. , BJÖRCK I.
Published: July 2010

The protein nutritional value of pigskins and bovine tendons, with collagen contents of 75 and 95% respectively, was evaluated using amino acid analyses and nitrogen balance experiments on rats. Pigskins contain somewhat higher amounts of tryptophan, meth‐ionine, cystine and tyrosine than tendons. The amounts of several essential amino acids were low. The true digestibilities were for young (4 month old), unscalded pigskin 96.1%, old (5 year old), unscalded pigskin 92.5%, calf tendon 97.3% and cow tendon 92.4%. Small but statistically significant differences due to the animal age were observed. Insoluble collagen, extracted from bovine tendon, had a digestibility of 95.2%. Wet heat treatment of old pigskin and cow tendon samples at 74â°C for 30 min significantly increased the digestibilities to 96.3 and 97.3% respectively. The results indicate that prior denaturation of collagen, as obtained by, for example, heat treat‐ment, is not necessary for the digestion of pigskin and tendon in rats.
Effect of frozen storage on protein denaturation in bovine muscle.
Authors: WAGNER J. R. , AÑÓN M. C.
Published: July 2010

The effect of frozen storage on the solubility, viscosity, rheological and electrophoretic behaviour of myofibrils was studied. The solubility, viscosity, swelling and thixotropic behaviour of myofibrils showed a period in which it was constant or changed slowly, and then began to decrease. The results obtained by polyacrylamide gel electrophoresis indicated that during storage the formation of aggregates occurred in addition to alteration in the actin‐myosin interaction. These results were correlated with those obtained from measurements of viscosity, rheological behaviour and swelling of myofibrils in solution.
Determination of chloride, nitrate and calcium ions in sugar with ion selective‐electrodes
Authors: KARIM M. T. , NAJIB F. M. , MOHAMMAD M. S.
Published: July 2010

Chloride, nitrate, and calcium ion‐selective electrodes were tested and found satisfactory for the determination of the corresponding ions in highly refined white sugar, molasses and other impure sugar samples at different stages of sugar manufacturing or refining. The interferences by Br− and I− ions in Cl− determination were eliminated by oxidation with 3 M HNO3 and passing air to remove the free Br2 and I2 formed. The Cl− concentration was then determined with a chloride‐selective electrode against a calibration curve. Chloride should not be determined by ashing sugar, since this causes high losses of Cl−. It was found that NO3− and free Ca2+ ions could be determined directly in the sugar solution against corresponding calibration curves. Total calcium was determined after ashing of sugar samples. The ash was dissolved in 0.1 M HCl and passed through an anion exchange resin to remove PO3−4 and SiO2−3 ions, and Ca2+ was determined as before. Bound calcium was obtained by subtracting values of free from total calcium. Determination of bound calcium was useful to monitor the process of liming. For comparison, the three ions were also determined with acceptable precision without removing interfering ions using the method of standard addition and Gran's plot. The errors of determination for both direct and standard addition techniques were 3% for Cl− and NO−3 and 1–5% for Ca2+.
Thermal properties of potatoes and a computer simulation model of a blanching process
Authors: LAMBERG I. , HALLSTRÖM B.
Published: July 2010

Thermal conductivity and specific heat were experimentally determined in Bintje potatoes. The methods used were a transient hot‐strip method and differential scanning calorimetry respectively. The results from the experiments were used in a theoretical calculation model using the finite element technique. Temperature profiles and heat transfer coefficients were simulated and the theoretical calculations were compared with experimental data for the blanching process. The correlation between experi‐mental data and theoretical calculations was good if the heat transfer coefficient was assumed to be 750 W/m2°C.
Effects of polysaccharide stabilizers on the nucleation of ice
Authors: MUHR A. H. , BLANSHARD J. M. V. , SHEARD S. J.
Published: July 2010

Sodium alginate, methyl cellulose and sodium carboxymethyl cellulose at concentrations of ∼ 1% do not change the homogeneous nucleation temperature (TH) of water or of sucrose solutions by more than the experimental uncertainty of ±2°C. Stabilizers at a concentration of 0.0067 g/ml showed a variety of effects on heterogeneous nucleation in 0.75 g/ml sucrose solution. Xanthan gum showed a slight inhibitory effect, methyl cellulose showed little effect, sodium pectate, sodium carboxymethyl cellulose and microcrystalline cellulose caused slight increases in the incidence of heterogeneous nucleation, and sodium alginate caused a substantial increase. The effect of sodium alginate can probably be attributed to inclusions rather than to the polysaccharide molecules themselves. It is concluded that none of the stabilizers affects nucleation of ice to an extent which would be of significance in frozen confectionery products.
Anthocyanin colorants from Elderberry (Sambucus nigra L.) IV. Further studies on production of liquid extracts, concentrates and freeze dried powders
Authors: BRØNNUM‐HANSEN K. , FLINK J. M.
Published: July 2010

Anthocyanin extraction from elderberry pomace is improved by mechanical disintegration and use of aqueous HCl in place of acidified ethanol as extractant, with pH being important in determining extractant effectiveness. Extraction at low solvent:pomace ratios gives extracts of higher concentration and lower volume, but with reduced efficiency. Enzyme pretreatments do not improve extractability from exten‐sively crushed pomace, and if of extended duration, can result in anthocyanin break‐down. Vacuum evaporation of extracts gave little loss of anthocyanins, and combined with freeze drying, produced materials with high anthocyanin retention.
Cold shock reactions in iced tropical fish
Authors: CURRAN C. A. , POULTEN R. G. , BRUETON A. , JONES N. S. D.
Published: July 2010

The development of a rigor mortis‐like stiffening and the biochemical changes associated with it were investigated in tilapia (Oreochromis aureus/niloticus hybrid), a tropical freshwater species, and common carp (Cyprinus carpio), a temperate freshwater fish, during storage in ice (0°C) and at ambient temperature (22°C). Onset of stiffening in carp occurred between 16 and 17 hr after death at both temperatures but full stiffness developed much later and was a longer duration at 0°C. In tilapia, onset occurred after 7 hr at 22°C and full stiffness was established after 19 hr. However, at 0°C, tilapia experienced a cold shock reaction such that they stiffened within minutes of being placed in ice and were fully rigid within 8 hr. Resolution of stiffness in this species also occurred later at 0°C. The rate of ATP degradation was similar under both storage conditions in tilapia but more rapid at ambient temperature in carp. Although the rate of lactic acid accumulation was faster at the higher temperature in tilapia, it was not nearly so marked as for carp. Objective measurement of contractions in excised muscle fibres from trout (Salmo gairdnerii) and tilapia indicated that reducing the temperature delayed the occurrence of the contraction and reduced its intensity. It was concluded that cold shock stiffening and rigor mortis stiffening are different.
Effect of handling treatment on fillet yields and quality of tropical fish
Authors: CURRAN C. A. , POULTER R. G. , BRUETON A. , JONES N. R. , JONES N. S. D.
Published: July 2010

The effect on fillet yields and quality of the cold shock reaction of tropical fish when they are iced immediately following death was investigated. Tilapia (Oreochromis moss‐ambicus/niloticus hybrid) were subjected to three handling treatments: filleting immediately following death; icing the whole fish immediately following death and filleting after 3 days; ageing the fish for 6 hr at ambient temperature prior to icing and then filleting after 3 days. All fillets were stored on ice until 9 days after death. Pre‐rigor filleting resulted in the highest filleting yields with the least drip loss and gaping on storage but the shortest shelf life. This was accompanied by the highest post‐mortem metabolic rate. The lowest yields and highest drip loss were obtained by icing the fish immediately at death followed by filleting after 3 days. A 6‐hr delay before icing gave yields and drip loss which were between these two extremes and also the slowest post‐mortem metabolism. The two post‐rigor filleting procedures produced fillets with increased gaping but a longer shelf life compared with pre‐rigor filleting. The implications of the cold shock reaction in terms of recommended codes of practice and handling operations in tropical fisheries are discussed.
Suitability of the Ottawa Pea Tenderometer to assess the quality of raw peas
Authors: GAZE R. R. , ATHERTON D. , HOLDSWORTH S. D.
Published: July 2010

This paper gives an account of the relationship obtained between the force readings for samples of peas using the Martin Pea Tenderometer, the Ottawa Pea Tenderometer and the Instron 1140 used with an Ottawa Pea Tenderometer food cell, together with sensory quality of canned and frozen peas and alcohol insoluble solids. The effect of temperature on the readings obtained for the different instruments, and the effect of interchangeability of Ottawa Pea Tenderometer cells and components are also reported together with information concerning the influence of bruising and damage to a sample of peas.
Determination of sorbic acid diffusivity in model food gels
Authors: GIANNAKOPOULOS A. , GUILBERT S.
Published: July 2010

The diffusional behaviour of sorbic acid in model food gels is discussed. The apparent diffusivity (Da) of sorbic acid in a aqueous gel containing 1.5%w/w agar, when determined by monodimensional diffusion (infinite gel columns) was found to be 8.8, 8.9 or 9.2 × 10−10 m2/sec at 25°C depending on the method of calculation (eye fitting, eye fitting graphical method or computerized fitting method) and 8.7 × 10−1 m2/sec when determined by tridimensional diffusion (gel cubes immersed into an appropriate solution).

The two methods displayed a good agreement; the tridimensional diffusion method had slightly worse repeatability than the monodimensional method (coefficient of variation 10% instead of 5.5% for the infinite gel columns) but has the advantage of being simple and rapid (1‐3 hr instead of 24 hr). For the tridimensional diffusion method, Da values of sorbic acid measured by inward and outward diffusion in gel cubes of different compositions were found to be not significantly different, which suggests an absence of partition effects between the immersion solution and the gel.

D
a values appear to be slightly dependent on the gelling agent concentration (1.5, 2.5 and 4% w/w agar) in gel containing 40% w/w glycerol and 60% water. Da values of sorbic acid decreased when the temperature decreased. An apparent activation energy of 18 KJ/mol was found for the diffusion of sorbic acid. This value was similar to the activation energy for the change in viscosity of the solution occluded in the gel network. Da values were influenced by the concentration of the diffusant, with a slight decrease when initial concentration of sorbic acid increased, following a linear relationship. The product D.η when η is the viscosity of the solution occluded in the gel was approximately constant.
Hedonic rating of food: single or side‐by‐side sample presentation?
Authors: McBRIDE R. L.
Published: July 2010

Taste panels made hedonic ratings of the sensory properties of four grades of sultanas, evaluated as two pairs (Experiment 1), three chicken casserole products (Experiment 2), and two cola drinks (Experiment 3). In each experiment, two modes of sample presentation were compared: single presentation, where panellists rated only one sample per session; and side‐by‐side presentation, where the samples were presented simultaneously. In Experiment 1, hedonic ratings from single presentation suggested there were no significant differences between grades, whereas the side‐by‐side presentation did indicate significant differences. This discrepancy between modes of presentation was not noted in Experiments 2 and 3. Selective operation of methodological bias in category rating might possibly account for the findings.
Technical note: loss of nitrate from carrots during blanching
Authors: VAROQUAUX P. , VAROQUAUX F. , TICHIT L.
Published: July 2010

Loss of nitrate from carrots during blanching was studied using several parameters, such as temperature of water, thickness of carrot slices, and volume ratio of carrots and water. It was found that the kinetics of nitrate diffusion fitted well to the Fick's general diffusion equation. Surface mass transfer coefficient (K) was related to temperature by an Arrhenius type reaction. The values of activation energy (Ea) and the constant K0 were calculated as 74 kJ/mole and 2769 × 103 kg/m2/sec. As expected the initial rates of diffusion were proportional to carrot surface and the efficiency of nitrate removal decreased with increasing blancher load. The proposed model may be used to determine the optimum blanching conditions of carrots in the baby food industry.
Review: Lactic acid: considerations in favour of its acceptance as a meat decontamininant
Authors: SMULDERS F. J. M. , BARENDSEN P. , VAN LOGTESTIJN J. G. , MOSSEL D. A. A. , VAN DER MAREL G. M.
Published: July 2010

Lactic acid occurs in a broad variety of foods consumed by man since times immemorial. At an appropriate pH it has bactericidal properties while not adversely affecting the sensory attributes of food. The suitability of lactic acid as a surface decontaminant for fresh meats, slaughter byproducts and poultry were studied with special reference to markedly reducing the contamination with enteropathogenic Enterobacteriaceue and Campylobacter spp. and extension of shelf life under refrigeration. Discoloration of meat surfaces does not occur at concentrations of approximately 1% v/v lactic acid, at pH = 2.4. Up to 2% does not cause off‐flavours in meat. Such treatments result in a significant reduction of the bacterial flora, not only by means of a pH drop but also by a specific action of the acid in the undissociated form. Undesirable flora shifts favouring pathogenic microorganisms at the cost of microbial antagonists have not been observed. Since there are no indications that lactic acid decontamination of meats could in any sense endanger human health, public health authorities would seem well advised to allow meat processing plants to use lactic acid as a decontaminating agent, provided they adhere to the strict conditions of Good Manufacturing Practice (GMP).
Effect of chilled storage of radiation‐pasteurized chicken carcasses on the eating quality of the resultant cooked meat*
Authors: BASKER D. , KLINGER I. , LAPIDOT M. , EISENBERG E.
Published: July 2010

Chicken carcasses were γ‐irradiated with about 3.7 kGy whilst at 0°C, and stored at from +1° to +2°C. Sensory panels found that the eating quality of leg meat was satisfactory for at least 1 week, and decreased after about 3 weeks. Breast meat changed, but was satisfactory for about 3 weeks, decreasing in quality after about 4 weeks.
Optimization of colour in commercial port blends
Authors: WILLIAMS A. A. , BAINES C. R. , FINNIE M. S.
Published: July 2010

Simple quantitative descriptive analysis coupled with ratio scaling techniques were used by a consumer panel for the objective assessment of fifteen ports, derived from blending Ruby, Tawny and White ports in varying proportions, for redness, brownness and intensity of colour. Deviation of the amounts of these attributes from those in the consumer's concept of an ideal port, both for Ruby and Tawny drinkers, was determined in relation to blend composition and L*, a* and b* values. Inverse simultaneous regression procedures showed the ports which best satisfied the two consumer subsets (Ruby and Tawny drinkers), in respect to all the sensory attributes, had chroma values of 23.0 and 21.8, and hue angles of 37.3 and 45.1° respectively. This corresponded to L*, a* and b* values of 86.13, 18.24 and 13.9 for the Ruby drinkers, and 92.1,15.3 and 15.4 for the Tawny drinkers.
Simple enrichment procedure for the estimation of minor polyunsaturated fatty acids in food fats
Authors: PEERS K. E. , COXON D. T.
Published: July 2010

A simple, reliable and sensitive method, involving the partition of a mixture of fatty acid methyl esters (FAME) between hydrocarbon solvent and aqueous ethanolic silver nitrate, is described for the estimation of low concentrations of polyunsaturated fatty acids (PUFA) in fats and oils. It is suggested that this procedure could be used to give an indication of oxidative stability of food fats and of their potential for off‐flavour development.
Frozen storage life of the Bolivian fish, sabalo (Prochilodus platensis)
Authors: CURRAN C. A. , AMES G. R. , JONES N. S. D.
Published: July 2010

A supply of the Bolivian fish sabalo, Prochilodus platensis, was stored at ‐15° and −30°C. Samples were taken at intervals for analysis and taste panel assessment. No significant change was observed in 20 months at either temperature in the pH or in the percentage of protein soluble in 5% sodium chloride. The fish remained acceptable to the taste panel throughout. Thus the storage life of the species is shown to be in excess of 20 months at both −15° and −30°C.
Comparison of selected food characteristics of three cultivars of bean Phaseolus vulgaris
Authors: PAREDES‐LÓPEZ O. , MONTES‐RIBERA R. , GONZÁLEZ‐CASTAÑEDA J. , ARROYO‐FIGUEROA M. G.
Published: July 2010

Three bean (Phaseolus vulgaris) cultivars were selected to study some of the physical properties of the seeds, hydration capacity, cooking time, phytic acid content, digestibility, colour changes as a function of soaking and cooking, and sensory properties. These cultivars were bayocel, canario 101 and flor de mayo. The water uptake was much lower for the cultivar with larger seeds. Some slight losses of phytic acid were found due to the cooking treatment; cooking improved the protein digestibility. The cultivar flor de mayo exhibited the most desirable sensory attributes.
Technical note: Kinetics of sorbic acid loss during storage of peaches preserved by combined factors
Authors: GERSCHENSON L. N. , ALZAMORA S. M. , CHIRIFE J.
Published: July 2010

It was found that the loss of sorbic acid in stored peaches preserved by combined factors (water activity, pH, additives) followed first order reaction kinetics. Rate constants and activation energy (14 kcal/mol) were almost identical to those previously reported for sorbic acid loss in concentrated glucose solutions of identical water activity and pH.
Assessment of the previous heat treatment given to meat products in the temperature range 40°–90°C. Part 1: Soluble nitrogen analysis
Authors: PARSONS SUSAN E. , PATTERSON R. L. S.
Published: July 2010

The aim of this work was to identify a technique which would yield information retrospectively about the heat treatment applied to a meat product in the temperature range 40–90°C. Saline extracts of beef samples (M. longissimus dorsi and M. semi‐membranosus) of known heat treatment, were analysed for soluble nitrogen by Kjeldahl analysis. The amount of residual soluble nitrogen in an extract was found to decrease as the cooking temperature increased, with the major reduction occurring between 40 and 70°C. A good correlation between nitrogen values was obtained for aliquots removed from a continuously heated raw meat extract, 5 mm slices and the centre sections of 60 mm cubes. It was also possible to detect differences in the extent of heating achieved at points between the surface and the centre of the solid piece of meat. These results indicate that it may be possible to estimate in retrospect the approximate maximum temperature reached in an unknown cooked meat sample by reference to a standard curve of soluble nitrogen versus known heat treatment.
Assessment of the previous heat treatment given to meat products in the temperature range 40°–90°C. Part 2: Differential scanning calorimetry, a preliminary study
Authors: PARSONS SUSAN E. , PATTERSON R. L. S.
Published: July 2010

Differential scanning calorimetry (DSC) was examined as a potential method for determination of the previous heat treatment of a meat product. Samples of beef (M. longissimus dorsi and M. semimembranosus) were given a known heat treatment using a thermostatically controlled waterbath or the DSC instrument itself. Analysis in the DSC was then carried out over the temperature range 22–97°C at a heating rate of 10°/min. Raw beef was found to produce a three peak thermogram within the temperature range 45–90°C with peak maximum at 55, 66 and 79°C. As heat treatment is applied the peaks gradually disappear and variations in the cooked sample pattern can be related to the previously applied treatment. It appears that both the temperature and duration of heat treatment are important to the degree of denaturation and therefore the thermogram pattern. A promising correlation exists between maximum heat treatment temperature and the onset of denaturation obtained by DSC analysis, whilst the effect of duration of heat treatment is reflected in the area of the thermogram. It appears from the resultant thermograms that it may be possible to obtain an indication of the temperature and possibly duration of the previous heat treatment.
Flow behaviour and scanning electron microscopy of myosin B, soya protein components and mixtures at varying temperatures
Authors: LIN L. C. , ITO T.
Published: July 2010

The relationship of shear stress versus shear rate of myosin B, soya protein components and mixtures of them in solution was investigated at varying temperatures. Scanning electron microscopic observations were also made at varying temperatures. Myosin B solution showed thixotropic flow behaviour at room temperature, while the solution of soya protein components and the mixture of myosin B and soya protein components were rheopectic. Upon heating the rheopectic property of soya protein components and the mixture of myosin B and soya protein components became thixotropic. Scanning electron microscopic observations revealed that a three dimensional network was formed prior to gel formation on heating for myosin B and also for soya protein components and the mixture of myosin B and soya protein components. The results suggest that in these systems thixotropic flow behaviour precedes the formation of a protein gel on heating.
Viscosity modelling of dough in extrusion
Authors: BHATTACHARYA M. , HANNA M. A.
Published: July 2010

Effects of moisture level and shear rate on the rheoldgical properties of blends of corn gluten meal (CGM) and soy protein concentrate, were studied. A simple model was used to correlate extrusion dough viscosities as a function of moisture content and shear rate. The consistency index (m) and flow behaviour index (n) of the blends were determined. It is generally accepted that viscosity is a function of product composition. Our results indicated that individual constituent differences (e.g., protein type) also significantly affected viscosity. Pseudoplastic behaviour was observed during extrusion.
A general method for predicting the water activity of simple and multi‐component mixtures of solutes and non‐solutes
Authors: CAURIE M.
Published: July 2010

Caurie's (1985) equation for predicting the water activity (aW) of binary solutions has been revised by replacing molal concentration units and activity coefficient with equivalent expressions for weight concentration (g/kg H2O). Results obtained using the revised equation, which now applies to both solutes and non‐solutes, agree closely with measured literature values. The equation reveals that the relationship between the weight concentration of solute/non‐solute binary solution or dispersion and the corresponding aW exhibits a minimum for carbohydrates and proteins. Electrolytes exhibit no such minimum and are the most effective in depressing aW while proteins are the least effective. The substitution of the new binary equation into the Ross (1975) equation results in an equation for a mixture identical with the recently corrected Ross one (Caurie, 1985), except that the correction factor in the new equation is expressed in g/kg H2O making it applicable to simple and multi‐component mixtures of both solutes and non‐solutes. The new equation has been applied to literature data from various sources and has been found to agree very closely with measured values.
Technical note: Effect of low pH preservation on the colour and consistency of tomato juice
Authors: MUDAHAR G. S. , SIDHU J. S. , MINHAS K. S.
Published: July 2010

The changes in colour and consistency are reported for tomato juice produced by low pH preservation and stored under ambient conditions. The juice preserved under acid conditions showed higher consistency, probably due to the higher concentration of pectin and the presence of low methoxyl pectin. The furfural and hydroxymethyl‐furfural which were detected in the juice indicated that darkening of the juice colour was due to non‐enzymic browning involving both ascorbic acid and sugars (hexoses). Although the retention of ascorbic acid was higher under low pH conditions, it led to a significant darkening of the juice colour due to non‐enzymic browning involving mainly ascorbic acid.
Factors influencing the determination of nisin in meat products
Authors: BELL R. G. , LACY K. M. DE
Published: July 2010

Recovery of nisin from minced meat and meat emulsions was poor and variable. The rate of recovery was little affected by the presence of NaCl and/or NaNO2, particle size, or the meat to extractant (0.02N HCl) ratio, but was significantly affected by the fat content of the meat. For nisin added at 100 iu/g, recoveries at the optimal meat to extractant ratio, 10% wt/wt suspension, ranged from 26% at 3% fat to 76% at 83% fat. At addition levels of 200 iu/g and greater, nisin recovery efficiency was reduced.
Effect of frozen storage on protein denaturation in bovine muscle 1. Myofibrillar ATPase activity and differential scanning calorimetric studies
Authors: WAGNER J. R. , AÑON M. C.
Published: July 2010

The effect of frozen storage on myofibrillar ATPase activity and thermal transitions in bovine muscle was investigated. Myofibrillar ATPase activity and total enthalpy of denaturation (ΔH) decreased with time of storage. The rate of decrease was lower at −20°C than at −5°C or −10°C. Differences in behaviour during storage of muscle after fast or slow freezing could be attributed to differences in ice recrystallization. The observed decreases in area of the first peak seen in the thermograms and Ca2+‐myo‐fibrillar ATPase activity show that the myosin head denaturated progressively during storage. The myosin tail also denaturated during storage but the thin filament remained unaltered. Kinetic analysis suggested that the denaturation of the myofibrillar proteins took place through two consecutive first order reactions; an initial rapid reaction followed by a slower one.
Effects of additions, irradiation and heating on the activity of Trimethylamine oxide‐ase in frozen stored minced fillets of whiting
Authors: PONTE D. J. B. DA , ROOZEN J. P. , PILNIK W.
Published: July 2010

Fish fluid was obtained by centrifuging minced fillets of whiting and used to study the effects of several treatments on TMAO‐ase activity during storage at — 18°C. Additional experiments were carried out with the whole mince. When the fish fluid or mince was heated for 1 min at 80°C or more, the production of dimethylamine and formaldehyde ceased. Xanthan was the only one of the hydrocolloids studied (pectins, carrageenans, alginates, locust bean gum and carboxymethyl celluloses), which showed a significant reduction of TMAO‐ase activity. A low dose of irradiation (300 Krad) did not change TMAO degradation of the fish fluid during subsequent frozen storage.
Shrinkage in canned mushrooms treated with xanthan gum as a pre‐blanch soak treatment
Authors: GORMLEY T. R. , WALSHE P. E.
Published: July 2010

Vacuum treating freshly harvested mushrooms with a 1% xanthan gum solution (XVT) containing 0.25% sodium metabisulphite (SMBS) prior to blanching and canning gave a lower shrinkage value than for corresponding samples vacuum treated with water, or those canned by conventional means or the 3S process. A combination of chill storage (2‐4°C) for 1‐3 days coupled with 1% XVT was found best and gave even lower total canning losses (chill storage loss + blanch loss + retort loss); these were 6% lower than in the 3S process and 11.5% lower than for mushrooms canned by the conventional procedure. These data suggest that xanthan gum has considerable potential for reducing shrinkage in canned mushrooms. The XVT canned samples had an excellent colour and an acceptable texture. Further storage tests over a 9 month period with xanthan treated canned mushrooms showed than an SMBS level of 0.1% in the pre‐blanch soak solution maintained an excellent colour in the canned product. No in‐can mushroom shrinkage took place during the 9 month storage test.
Effect of drying on the quality of milled rice
Authors: AGUERRE R. , SUÁREZ C. , VIOLLAZ P. E.
Published: July 2010

The effect of drying on the quality of milled rice was investigated. Variables studied were drying temperature, air velocity and air relative humidity. The degree of breakage during milling increased as temperature of drying increased (from 40 to 70°C) and relative humidity decreased. Varying the air velocity between 0.26 and 2.12 m/sec had no effect on breakage. The‘activation energy’ of grain breakage was much higher than of drying.
Studies on production of a ghee‐like product from vegetable fats
Authors: ISKANDER M. H. , SHALABI S. I.
Published: July 2010

A typical ghee flavour was obtained by heating vegetable fats with fermented milk or fermented whey at 125°C for 2 min. The resulting product had an acceptability preference and better storage stability than the untreated vegetable fat. It is suggested that whey proteins and fermentation products are the major contributors to development of ghee flavour in vegetable fats. The increase in storage stability could be due to the formation of reactive sulphydryl groups from whey proteins during the heating process.
Sorption properties of raw hake muscle
Authors: MOSCHIAR S. , FARDÍN J. P.
Published: July 2010

Adsorption and desorption isotherms of raw hake (Merlucius hubbsi) muscle were determined at 5, 20 and 30°C. From the temperature dependence of the isotherms, isosteric heats of sorption were evaluated by means of the Clausius‐Clapeyron equation. Monolayer moisture contents are calculated by means of the B.E.T. analysis. The magnitude of the hysteresis between desorption and adsorption isotherms was quantified. Results are compared with those reported in the literature for other fish species.
Optimization of yield and properties of silken tofu from soybeans.
Authors: BEDDOWS C. G. , WONG J.
Published: July 2010

The extraction phase of the preparation of silken tofu was investigated and the ratio of beans:water was shown to be very critical in terms of the amount of protein extracted and the properties of the tofu. In the range 9–14:1, 10:1 gave the best result. Extraction at 8:1 and making up to 10:1 gave much poorer results, but maceration at 8:1 followed by a further extraction at 2:1 gave a better quality tofu. The time of maceration was shown to have a pronounced effect on the amount of protein extracted.
Optimization of yield and properties of silken tofu from soybeans.
Authors: BEDDOWS C. G. , WONG J.
Published: July 2010

The effect of various heat treatments on the yield, protein content and physical form of silken tofu was investigated. Better yields and quality were obtained when the macerated bean slurry was filtered prior to heating and a defined rate of heating was used with stirring. The optimum coagulation temperature was 75–80°C.
Cassava detoxication during tapé fermentation with traditional inoculum
Authors: ARIHANTANA M. B. , BUCKLE K. A.
Published: July 2010

Tapé ketela is a traditional Indonesian fermented cassava product using ragi as inoculum. Cassava fermented with 0.2–0.4% ragi produced a characteristic flavour and sweet‐sour alcoholic taste. After 3 days' fermentation the pH decreased from 6.54 to 5.06–5.17, titratable acidity increased from 0.07 to 0.22–0.26%, reducing and total sugars increased from 1.1 to 21.4–22.0% and 3.9 to 22.9–23.5%, respectively, while alcohol content increased from less than 0.01 to 2.02–2.12%. Total cyanide loss during fermentation was 58–87%. Most cyanide was lost during steaming (40–70%) while 9–35% was lost during 3 days fermentation. Sensory evaluation revealed no significant differences in flavour, texture and colour (P > 0.01) of tapé prepared by two different methods. Tapé prepared from dried cassava (gaplek) did not develop characteristic organoleptic properties.
A simple, rapid and sensitive method for monitoring contamination of aseptically processed tomato paste
Authors: MALLIDIS C. G. , SAMARAS F.
Published: July 2010

A simple, rapid and sensitive method for the detection of microbial contamination of the system of aseptically processing tomato paste has been developed. The method involves the rapid growth of any lactobacilli present in the product and detection of metabolites produced by these micro‐organisms. The metabolites used are acetoin, diacetyl, carbon dioxide and lactic acid. It was found that with this method it is possible to detect the presence of both homofermentative and heterofermentative lactobacilli within 10–25 hr, depending on the level of contamination.
Identification of irradiated spices with thermo‐and chemiluminescence measurements
Authors: HEIDE L. , BÖGL W.
Published: July 2010

Thermoluminescence and chemiluminescence intensities of twenty‐nine different spices were measured to determine whether the techniques could be used to detect if spices had been irradiated (10 kGy) and stored after irradiation. In each case it was possible to identify radiation treatment with 10 kGy by at least one of the two methods, if irradiation occurred 2–3 weeks prior to the examination. The luminescence effect from radiation treatment differs from spice to spice. Intensity increases in samples treated with 10 kGy vary between 1 (no effect) and about 1000 times compared with untreated samples. Thermoluminescence proved to be more useful than chemiluminescence, as with most spices radiation treatment could be identified after longer periods of time. A combined or simultaneous use of both techniques assures a rapid identification of radiation treatment in most of the examined spices. With the exception of garlic, onions, white and black pepper, the irradiated spices can be identified more than 6 months after irradiation. Some, curcuma, juniper berries, basil, chillis, paprika and celery, show increased luminescence intensities for a year or longer after irradiation.