bluuebunny/crossref_metadata_2025 huggingface dataset:
Modified atmosphere packaging of broccoli florets
Authors: BALLANTYNE ALISON , STARK R. , SELMAN J. D.
Published: July 2010

A retail packaging system was used to study the atmosphere modification which developed within sealed packages of prepared broccoli florets with a range of polymer films of different gas permeabilities (oxygen permeability 3000–32,500 ml/m2/day/atm). Three methods of sealing were investigated and modified atmospheres (MA) were produced both naturally by respiration and by application of gas flushing techniques. The effects of these MA conditions on sensory quality were observed by monitoring colour change and development of off‐odours. A 2–3% O2, 2–3% CO2 equilibrium MA was established using LF film to package broccoli florets when stored at 5°C. This, the only consistently aerobic MA attained, did not markedly improve retention of quality of broccoli florets when compared with broccoli stored in air. When broccoli florets were packaged with films which resulted in very low O2 atmospheres (1% or less) foul of‐odours shortened broccoli storage life.
Construction of a computer‐controlled thermoresistometer for the determination of the heat resistance of bacterial spores over the temperature range 100 to 150°C
Authors: BROWN K. L. , GAZE JOY E. , McCLEMENT R. H. , WITHERS P.
Published: July 2010

A computer‐controlled thermoresistometer for the determination of the heat resistance of bacterial spores has been designed and constructed. The thermoresistometer is capable of operating between 100 and 150°C0.1°C with exposusre times as short as 0.1 sec. Five samples (0.01 ml) of spore suspension can be exposed to steam at each time/temperature combination using a computer‐controlled piston‐driven exposure system. Temperature control of the apparatus is achieved using platinum resistance probes linked to the computer, which then actuates a variable steam control valve.
The heat resistance of spores of Clostridium botulinum 213B over the temperature range 120 to 140°C
Authors: GAZE JOY E. , BROWN K. L.
Published: July 2010

The heat resistance of spores of Clostridium botulinum strain 213B heated in phosphate buffer (pH 7.0) was determined over the temperature range 120 to 140°C using a computer controlled thermoresistometer. The predicted D121°C value of approximately 0.13 min and z value of 11.0°C (obtained by linear regression) was close to the classical D121°C of 0.2 min and z value of 10°C used in process calculations. These data indicated that, according to the heat resistance of this culture, the z value of C. botulinum can be considered constant over the whole range 120 to 140°C. This also provided support for the recommended classical process calculations, using a z value of 10.0°C, being adequate if extrapolated to 140°C.
Moisture diffusivities for bran and endosperm during soaking of long‐grain brown rice
Authors: HENDRICKX M. , LAUWERENS C. , TOBBACK P.
Published: July 2010

A three‐dimensional transmission line matrix (TLM) model, using axisymmetric elements, was developed for describing moisture diffusion during the soaking of long‐grain brown rice. On the basis of this model, moisture diffusivities for bran and endosperm were calculated as a function of temperature. Endosperm diffusivities of 0.92, 1.08 and 1.26X10‐10 m2 s‐1 and bran diffusivities of 0.11, 0.18 and 0.37x10‐10 m2 s‐1 were found, both at 30, 40 and 50°C respectively. The activation energies for moisture diffusion were calculated to be 13.08 and 49.85 kJ mol‐1 for endosperm and bran respectively.
A circular dichroism study of the effect of some organic solvents on the actomyosin of sardine (Sardinops melanosticta)
Authors: WON M. PEREZ , IYAMA S. , SHINOHARA K. , MURAKAMI H. , OMURA H.
Published: July 2010

Circular dichroism (CD) was used to study changes in conformation of sardine (Sardinops melanosticta) actomyosin after treatment with some organic solvents. Untreated sardine actomyosin showed two negative bands at 208 and 222 nm, typical of proteins possessing α‐helix configurations. The water‐miscible alcohols methanol, ethanol, isopropanol and n‐butanol, and the water‐immiscible solvents n‐hexane, n‐octanol, and dichloromethane altered the native conformation of sardine actomyosin. The degree of alteration of native sardine actomyosin was principally dependent on the alcohol concentration and temperature used for dewatering. The least damage occurred with isopropanol, or with 10 or 90% aqueous ethanol; most damage occurred with 40–50% aqueous ethanol. Dichloromethane and n‐butanol increased the α‐helical content of the native protein. Treatment with hydrophilic and hydrophobic solvents at 70 and 20°C unfolded the protein to form a random coil, but defatting treatment at 2°C caused little damage.
Effect of skin addition on the technological properties of comminuted chicken meat emulsions
Authors: SMOLINSKA T. , KOPEC W. , TRZISZKA T.
Published: July 2010

Possibility of using skin supplement as collagen raw material (substituting leg muscles) in highly comminuted sausages made from breast muscles was investigated. It was found that 5% skin added to the comminuted breast muscles resulted in the collagen content equal to that obtained with 40% leg muscles. Addition of 5% skin to the breast muscles decreases emulsifying capacity of protein extracts but increases thermal stability, and changes the flow curve of meat emulsions more than the addition of dark muscles. The skin used instead of leg muscles does not change sausage binding (shear force) and overall sensory value, but reduces water‐holding capacity and palat‐ability of sausages.
Effect of water content on the mobility of solute molecules and of protein side chains in casemate preparations
Authors: MESTE MARTINE LE , DUCKWORTH R. B.
Published: July 2010

The effect of water content on the mobility of small solute molecules and of casein side chains was studied by electron spin resonance in caseinate/water systems. The immobilization of nitroxide probes of different sizes and properties were followed during progressive dehydration of concentrated caseinate preparations (3 g H2O/g dry protein). Above a characteristic minimum moisture content a linear relationship was observed between the rotational diffusivity and water content. The slope of the straight lines depended upon the size of the probe and upon the nature of the interactions with the protein. Nitroxide labels were covalently bound to caseinate and the changes in the flexibility of the side chains as hydration changed were followed. The results are discussed in relation to the solvent properties of water, and to recent suggestions concerning the significance, for stability, of the glass transition phenomenon in such materials.
Effect of dimensions on the hating times and wieght losses of cylindrical beef joints
Authors: Burfoot D. , Griffin Wendy J.
Published: July 2010

The heating time and weight loss of cylindrical joints of lean beef in twenty‐five length/diameter combinations (five lengths from 28 to 160 mm and five diameters from 14 to 80 mm) were measured when heating the meat to a minimum internal temperature of 74°C in a natural convection oven at 175°C.

Cooking weight loss was not affected by joint diameter but decreased very slightly with length. Heating time to 74C increased with joint length and asymptotically approached the heating time for an infinitely long cylinder. The variation of heating time with joint diameter and length was predicted using a mathematical model.

Comparison of the results with other published work showed that weight loss from the lean component of joints is not affected by fat cover.
Improved utilization of flesh from mackerel as salted dried fish cakes
Authors: AKANDE G. R. , KNOWLES M. J. , TAYLOR K. D. A.
Published: July 2010

The composition and yield of mince prepared by passing mackerel (S. scombrus) frames through a flesh‐bone separator were determined. Salt (10 to 40%) was added to the unwashed mince to prepare dried cakes with enhanced keeping quality. The dried cakes were assessed for peroxide and TBA values, total viable count and for sensory attributes after preparation and after a 3‐month storage period at 29±1°C. The cakes were reconstituted by desalting in boiling water. Salted dried cakes prepared with 15,20,30 and 40% salt were found to be stable and have little sensory deterioration over the 3‐month storage period which is adequate to simulate distribution of products at tropical ambient temperature.
Guava puree with reduced stone cell content: preparation and characteristics of concentrates and nectars
Authors: WEINERT I. A. G. , van WYK P. J.
Published: July 2010

A decanter centrifuge was used to decrease the content of stone cells in guava puree before evaporation. Concentration factors between 3.3‐ and 4.3‐fold were achieved. Thirty‐seven per cent of the stone cells could be removed in a small decanter, whereas virtually all sclereids are removed on an industrial scale. Small significant increases in moisture contents, total soluble solids and titratable acidity and decreases in pectin fractions and ascorbic acid contents (average 38%) occurred during processing; guava colour became darker, redder and less yellow. The apparent viscosity of the puree decreased after centrifugation and increased again during evaporation. Nectars prepared from puree with reduced stone cell content were the most stable. Concentration of puree reduced cloud stability of nectars by up to 34% after 35 days storage, but homogenization improved the stability. Panel members only found significant differences in the colour of nectars prepared from the three concentrates.
Review: Flow injection analysis–a new technique for food and beverage analysis
Authors: OSBORNE B. G. , TYSON J. F.
Published: July 2010

Flow injection analysis affords a means of automating many traditional wet chemical methods of food and beverage analysis, and introducing new methods which have no conventional analogue. In this technique, reactions are carried out in a continuous flow mode and it is not necessary for a state of chemical equilibrium to be reached. Therefore, analyses using standard or official chemistries may be achieved in very short times (typically 30 sec). This review outlines the principles, instrumentation and techniques of flow injection analysis and considers the scope of its actual and potential applications in food and beverage analysis.
Modelling the effect of peanut and cowpea flour supplementation on quality of Chinese‐type noodles
Authors: CHOMPREEDA P. , RESURRECCION A. V. A. , HUNG Y.‐C. , BEUCHAT L. R.
Published: July 2010

Chinese‐type noodles were prepared from wheat flour fortified with 7–21% defatted peanut and 4–12% cowpea flours. A full factorial 4X4 design was used. Fifteen supplemented Chinese‐type noodle formulae and a control sample were analysed for protein content and physical and sensory qualities. The protein content of noodles was increased as the level of peanut/cowpea flours increased. Colour and cutting force of supplemented noodles were affected negatively by cowpea and peanut flours, respectively. Sensory scores for firmness and yellowness of supplemented Chinese‐type noodles were decreased as the level of peanut/cowpea flours increased. Computer‐generated response surface and contour plot interpretations revealed that up to 15% peanut flour and 8% cowpea flour supplementation will produce acceptable supplemented Chinese noodles with high protein content (21%).
Perceptions of peanuts and related products by Thai consumers in the U.S.
Authors: SUKHUMSUVUN S. , RESURRECCION A. V. A.
Published: July 2010

A study was conducted to identify perceptions of Thai consumers toward peanuts and related products using a food/food‐use appropriateness matrix and to identify new peanut products that exhibit good potential for being accepted by Thais. Most respondents were highly educated young Thai adults who had resided in the U.S. for 4 years or less. Factor analysis of the matrix consisting of sixteen peanut and related products and fourteen use situations identified two food (snack food and every day food) and three use groups (general use, special occasion and value/convenience). The snack food group was deemed appropriate for special occasions and children, while the every day food group was appropriate for general use and when concern existed about value and convenience. The every day food group was also perceived as being appropriate for snacking. Three peanut‐based products representing good potential for acceptance were identified as ice cream type, milk type and non‐peanut butter spread type.
Effects of water loss on apples in storage
Authors: HATFIELD S. G. S. , KNEE M.
Published: July 2010

Cox's apples were stored for up to 6 months in the presence or absence of anhydrous calcium chloride in an atmosphere containing 2% O2 and < 1% CO2 at 3.5°C, and effects on the physical properties of the fruit were assessed for up to 6 months. The desiccant was used to obtain an initial water loss of about 5% of fruit weight in the first 30 days of storage. In control fruit, turgor pressure appeared to be maintained during storage, and fruit volume increased as the air space in the fruit tissue increased. Initial weight loss lowered turgor pressure and prevented this increase. The force required to disrupt slices of apple in the Kramer shear cell was usually higher after initial weight loss, but resistance to the conventional penetrometer was little affected. Initial weight loss led to higher levels of soluble pectin and higher resistance to gaseous diffusion. In sensory tests the high weight‐loss fruit was firmer, tougher and less mealy than control fruit.
The extraction of carrageenan and its effect on the gel texture
Authors: ROTBART M. , NEEMAN I. , NUSSINOVITCH A. , KOPELMAN I. J. , COGAN U.
Published: July 2010

Carrageenan was extracted from Eucheuma cottonii under various conditions of temperature, alkalinity and time. The effect of process parameters on the rheological properties of the resulting carrageenan gels was studied. Raising the extraction temperature from 100 to 110°C under alkaline conditions increased the 3,6‐anhydrogalactose content, and extending the period of extraction up to 3 hr yielded gels with a higher gel strength and deformability modulus. Carrageenan gels were evaluated by compression on a Universal testing machine linked to a microcomputer system. This enabled continuous accumulation and processing of the force‐deformation data. The computerized method for texture analysis, presented in this study, enables rapid and accurate assessment of the gelling properties of crude carrageenans and of mixtures with other additives.
Comparison of a computer evaluation with a standard evaluation of retort pouch thermal processing
Authors: GOVARIS A. K. , SCHOLEFIELD J.
Published: July 2010

Flexible retort pouches (188x127x25.4 mm) filled with 10% bentonite suspension, tomato ketchup and potato puree were processed under computer control using steam‐air or hot water, and the heating/cooling curves and thermal diffusivities were determined. A computer method, developed for the evaluation of the thermal process using the one‐dimensional heat conduction equation, was used to calculate F0 values which were then compared with those obtained using the General‐ and the Stumbo's Formula methods. Temperatures at the pouch centre estimated by the Formula‐ and the Computer method were in good agreement with those obtained experimentally. The F0 values estimated by the computer method were closer to the F0 values estimated by the General method than those obtained by the Formula method.
Characteristics of surimi and kamaboko from sardines
Authors: ROUSSEL H. , CHEFTEL J. C.
Published: July 2010

Sardines of varying freshness (1 to 3 days in ice) were manually or mechanically processed into fish mince and surimi using 1 to 3 washing steps. Standard kamaboko gels were prepared by grinding thawed surimi with 3% NaCl and 5% potato starch, stuffing into sausage casings, holding at 37°C for 30 min and cooking at 90°C for 50 min.

Three washing steps decreased the yield of washed fish mince (21‐27 g per 100 g of whole fish), and the protein recovery (50‐55% of that present in the unwashed mince), but caused efficient lipid removal (80%) leading to surimi containing only 0.2‐1.4% lipid. The texture and colour of the final kamaboko were also improved.

The texture parameters (folding score, rigidity, elasticity index and gel strength) of kamaboko prepared from very fresh sardines were markedly enhanced by gel setting during incubation at 37°C for 30 min or 4°C for 24 hr. Incubation at 60°C for 30 min led to soft, coarse gels. Omitting potato starch or replacement by spray dried egg white had little effect on texture.

The texture of kamaboko prepared from less fresh sardines was less firm and elastic, did not improve when incubation was carried out at 37 or 4°C before cooking, and was softer and coarser after incubation at 60°C. Partial or total replacement of potato starch by egg white, soy protein isolate or bovine serum albumin markedly improved the texture. Egg white also increased the colour lightness.
A method of testing for irradiation of poultry
Authors: LEA J. S. , DODD N. J. F. , SWALLOW A. J.
Published: July 2010

A method for the detection of irradiated poultry is described. For chicken, free radicals produced by ionizing radiation within the hard crystalline matrix of bone can be detected by the technique of electron spin resonance (ESR) spectroscopy. The ESR signal increases linearly with dose over the likely commercial range and is stable over the probable shelf‐life under likely storage conditions. The lower limit of detection is equivalent to a radiation dose of 50 Gy. The test appears equally applicable to turkey, duck and goose.
Review: Kinetic parameters for thiamine degradation in foods and model solutions of high water activity
Authors: MAURI LILIANA M. , ALZAMORA STELLA M. , CHIRIFE J. , TOMIO MARÍA J.
Published: July 2010

Literature data for the rates of thiamine destruction in a wide variety of model systems, buffer solutions and foods have been used to determine the kinetics of thiamine destruction during processing. A range of conditions, including temperature, pH, oxygen and catalysts indicate that, in most cases, the destruction of thiamine follows first order reaction kinetics. When information is limited, these calculations may be used to extrapolate data and predict modifications of processing to minimize losses of thiamine.
Effect of lactic acid treatment during processing on the sensory quality and lactic acid content of fresh broiler chickens
Authors: VAN DER MAREL G. M. , DE VRIES A. W. , VAN LOGTESTIJN J. G. , MOSSEL D. A. A.
Published: July 2010

Microbial decontamination by lactic acid treatment during processing of fresh broiler chickens is an effective way to produce a safer product with good keeping quality. It remained to be assessed whether such a treatment adversely affects the organoleptic quality of the product. Lactic acid treatment results in an increased acid concentration in the skin, with no increase in lactic acid concentration in the underlying muscle tissue. Differences in sensory quality were only found in appearance of the carcasses, the controls being identified as discoloured. A preference test did not show any difference in lactic acid treated and untreated grilled legs.
Protein extraction from lupin seeds: microstructural aspects and hypothesis of mechanism
Authors: AGUILERA J. M.
Published: July 2010

Protein was extracted into water (pH 8.0, 1 h) from defatted lupin seed kernel particles (mean θ, 1425 μm). Intact and extracted particles were examined by scanning and transmission electron microscopy. The inner surface of the cell wall initially showed several small holes considered as possible sites of plasmodesmata. During extraction, protein bodies first became disrupted into smaller microstructures and then protein dissolved. Wide passages were formed between cells which allowed transport of protein. The molecular weight of proteins in solution did not change with time, suggesting that bulk flow rather than selective transport predominated.
Factors affecting the shelf‐life of precooked chilled roast pork
Authors: ROBSON C. P. , COLLISON R. , MACFIE H. J. H.
Published: July 2010

The microbiological, sensory and physicochemical changes in precooked chilled pork were measured over 8 days storage at 1°C and 5°C. Microbial growth was limited, but marked sensory and physicochemical changes occurred within the 5‐day period currently recommended as the maximum storage time in the DHSS guidelines on precooked chilled foods (DHSS, 1980). At 1°C, marked toughening occurred after only 1 day; whilst at 5°C adverse flavour and odour changes were noticeable by the fourth day of storage. The amount of volatile compounds, especially n‐hexanal, stripped from the pork increased significantly over the 8‐day storage period, particularly at 5°C.
The effect of slaughter method on the quality of rainbow trout (Salmo gairdneri) during storage on ice
Authors: AZAM K. , MACKIE I. M. , SMITH J.
Published: July 2010

Rainbow trout (Salmo gairdneri) were stunned by electrocution, exposure to elevated concentrations of carbon dioxide and by a blow to the head, and subsequently bled. The fish were stored ungutted in ice for up to 15 days, and the changes in the textural properties of the flesh of the fish were measured by a sensory panel and with a texturometer. Parallel changes in the concentrations of spoilage‐related biochemical constituents, in water‐holding capacity and in bacterial counts were also determined. Slaughter by electrocution and by carbon dioxide narcotization led to a greater initial production of lactic acid and a slightly reduced pH, compared with slaughter by a blow to the head. No significant differences were found in the values of the other indices of quality, either immediately after death or during post‐mortem storage.
Influence of post‐mortem treatments on turkey and chicken meat texture
Authors: WAKEFIELD DIANE K. , DRANSFIELD E. , DOWN N. F. , TAYLOR A. A.
Published: July 2010

Toughness of poultry breast muscle was influenced by the rate of rigor onset, the rate of cooling and chilled storage time. The pH of the breast muscle at 20 min after stunning (pH20) in 52‐day‐old chickens varied from 5.9 to 6.9, and in 70‐day‐old turkeys from 6.2 to 6.8. In turkey meat with pH20 > 6.4, toughening was induced by immersion chilling to 7°C within 65 min post mortem and subsequent ‘tanking’ in iced water. Unaged, thawed meat from chicken carcasses, in which freezing commenced about 2 h after stunning was tougher than that from carcasses chilled for 16 h before freezing. Both were tender after 7 days chilled storage. Electrical stimulation of carcasses using 94 V decreased pH20 by an average of 0.3 unit in turkey, with no overall increase in tenderness. In chicken, it decreased the pH20 by 0.5 unit, but caused an overall toughening due to increased rigor shortening in carcasses with pH20 < 5.8.
Rheological properties of flour and sensory characteristics of bread made from germinated chickpea
Authors: LUZ FERNANDEZ MARIA , BERRY J. W.
Published: July 2010

Breads were prepared from wheat flour supplemented with 0,10,20 and 30% ungerminated or germinated chickpea flour to determine the influence of germination on the sensory acceptability of the baked products. Rheological characteristics of the flours were evaluated by the Brabender farinograph and viscoamylograph, using a wheat flour control. Farinograph development and stability times decreased, and amylograph peak viscosities increased for all fortified flours. Germinated flours showed greater retrogradation upon cooling. Most sensory characteristics of fortified breads did not differ significantly, but the chickpea loaf fortified with 10% germinated flour did not compare favourably with the control.
The foam‐enhancing properties of basic biopolymers
Authors: POOLE S.
Published: July 2010

Protein systems containing both basic (high isoelectric point) and acidic (low isoelectric point) components exhibit markedly enhanced foaming properties, to an extent that significant amounts of lipids (up to 30% by weight) can be tolerated without detriment. The enhancement in foaming results from increased protein‐protein interactions at the bubble surface, giving a more resilient film. Lipids, even at low levels, usually inhibit the foaming of proteins. Consequently, such mixed protein systems may have potential applications in the development of novel whipped foods.

The charge and structural requirements of basic proteins for foam enhancement have been identified. For practical purposes they must have an isoelectric point of 9 or greater and a molecular weight of 4000 daltons or greater.

Basic whey protein may be prepared by esterification in alcohol. This material has an isoelectric point between 9 and 9.5 and enhances the foaming of acidic proteins.

Chitosan, a basic polysaccharide obtained from fungi, crab and shrimp shells exhibits comparable or even superior foam‐enhancing properties to basic proteins, particularly low molecular weight forms. The foaming properties of different chitosan, protein and lipid formulations are reviewed, and potential areas of use of basic biopolymers in food processing are discussed.
An improved simple gravimetric method for measurement of high water activities
Authors: ESTEBAN M. A. , MARCOS A. , FERNANDEZ‐SALGUERO J. , ALCALA M.
Published: July 2010

A previously reported gravimetric method for measurement of water activity (aw) has been simplified and improved, to determine aw in the range from about 0.700 to 0.999. Extrapolated aw values above 0.990 gave average underestimates of –0.001 aw units with the improved method. Comparative results on various dairy products were in good agreement with those found by a reference method (thermocouple psychrometer). The differences between the results provided by both methods were smaller for products with very high aw values than for products with high and intermediate aw values.
Microbiological study of semi‐hard goat's milk cheese (Majorero)
Authors: GÓMEZ R. , PELÁEZ C. , DE LA TORRE E.
Published: July 2010

The development of microbial flora in industrially produced semi‐hard cheese made from pasteurized goat's milk was studied during manufacture and over a 90‐day ripening period.

Estimates of total count, streptococci, lactobacilli, leuconostocs, coliforms, micrococci and staphylococci, Staphylococcus aureus and yeasts and moulds were carried out at various stages of the ripening process; streptococci and lactobacilli were identified by species.

Initially, the total count increased rapidly, primarily as a result of the growth of mesophilic lactic streptococci mainly Streptococcus lactis and Strep, cremoris. Subsequently, both these counts stabilized or decreased. Lactobacilli increased, and by the end of the ripening period were the predominant microorganisms. Most common were Lactobacillus casei var. casei., especially at the end of storage; L. casei var. rhamnosus, L. casei var. plantarum and L. cellobiosus were also isolated. Leuconostocs were not found in any of the cheeses, and hence no eye formation took place. Coliforms, enterococci, yeasts and moulds remained below 102–103 c.f.u. g−1. Maximum levels of micrococci and staphylococci were found after 15–30 days of ripening and decreased gradually towards the end of the ripening period. Neither the milk curd, nor cheese contained Staph. aureus.
A modified distillation method for the detection of fat oxidation in foods
Authors: HOYLAND D. V. , TAYLOR A. J.
Published: July 2010

A rapid distillation procedure for the estimation of fat oxidation in food using the 2‐thiobarbituric acid test has been developed. The apparatus generates steam rapidly and allows high sample throughput while minimizing cleaning of glassware. Using the standard compound, tetramethoxypropane (TMP), and a number of food samples spiked with standard, the recovery of malondialdehyde was determined and suitable operating conditions selected. Levels of TMP equivalent to TBA numbers between 1 and 10 were used. Recovery of standard increased from 25.3% at 20 ml to 81.6% at 120 ml, and recoveries at different TBA numbers were similar. After consideration of various factors, 50 ml was chosen as the distillate volume and was collected in about 4 min. With food samples, the recovery varied depending on the composition of the food and, in order to determine TBA number, it was necessary to calculate recoveries from each type of sample. In the reaction of distillate with thiobarbituric acid, colour development was found to be extremely temperature sensitive, and careful temperature control of the heating bath was required.
The effect of pre‐drying temperature on the sorption properties of microcrystalline cellulose at temperatures up to 90°C
Authors: LEES A. , KENT M. , CHRISTIE R. H.
Published: July 2010

Using a specially‐constructed oven and sorbostats the sorption isosteres for microcrystalline cellulose have been obtained at temperatures between 25 and 90°C. Differences are shown between pre‐drying at 105°C and pre‐drying at the temperature of sorption. The sorption isosteres are not straight lines as expected.
Determination of water activity of canned fish using gravimetric, hygrometric and psychrometric methods
Authors: FERNANDEZ‐SALGUERO J. , ALCALA M. , MARCOS A. , ESTEBAN Ma. A. , CABEZAS L. , GOMEZ R.
Published: July 2010

The water activity (aw) of canned mackerel, tuna and sardine was determined using three methods: a gravimetric and two instrumental methods. The aw values obtained by the gravimetric method, which only requires simple laboratory apparatus, were not significantly different from the values obtained by the other two methods, and can be used to determine high aw values.
Effect of bicarbonate soaking on dehusking efficiency and composition of pigeon pea (Cajanus cajan L.) seeds and dhal
Authors: SAXENA R. P. , CHAND LAXMI , GARG G. K. , SINGH B. P. N.
Published: July 2010

Soaking pigeon pea seeds in 6% sodium bicarbonate solution for 1 h, followed by oven‐drying to 10% moisture improved dehusking efficiency from 66% in untreated seeds, or 71% in water‐soaked seeds similarly dried, to 94% yield of dhal. Treatment reduced gum and pectin content, increased enzyme activity, but caused losses in protein and starch content of the dhal.
A model for heat transfer in cryogenic food freezing
Authors: AWONORIN S. O.
Published: July 2010

An experimental study of the heat transfer between liquid nitrogen sprays and a model food (a gelatine slab) was carried out under conditions similar to those in a cryogenic freezer. Measurements of heat flux and local mass flow rates of the spray were made at various liquid N2 pressures and various temperature differences between the spray and the food surface.

At higher spray pressures, the heat transfer coefficient increases with the mass flux density of the liquid available at the food surface. The quantity of liquid nitrogen sprayed onto the solid surface, the mean droplet size, spray velocity, surface coverage and the mean temperature difference between the boiling nitrogen and the food surface are major factors influencing the rate of heat transfer during the freezing process. Although the heat transfer coefficients at the food surface are much less than those obtained for individual droplets, the model provides useful data.

The results are critically discussed in relation to cryogenic freezing of foods.
Reaction of apple pectin with ammonia
Authors: KRATCHANOV Chr. , DENEV P. , KRATCHANOVA M.
Published: July 2010

Amidated apple pectins were prepared in aqueous and aqueous‐alcoholic media, and the factors influencing both ammonolysis and hydrolysis of the ester groups of apple pectin by ammonia were studied.

In aqueous solution, the extent of ammonolysis and hydrolysis was very dependent upon ammonia concentration. In aqueous alcohol, the products were also dependent upon the particular alcohol and its concentration, increasing concentrations suppressing hydrolysis; the overall rate of reaction is much slower than in the absence of alcohol. The product balance between amonolysis and hydrolysis of the ester groups is influenced by the polarity of the medium, and by the concentration of NH+4 and OH−.

It was shown that the extents of ammonolysis and hydrolysis of the ester groups are significantly affected by the polarity of the medium and the acid‐base equilibrium of the interaction of ammonia with water, i.e. NH3+H2O ↔ NH+4+OH−. The content of free ester and amidated carboxyl groups in the pectin can be regulated by varying the concentration of ammonia, temperature, reaction time and the polarity of the medium. The rate of enzymic hydrolysis of amidated pectins decreases with increasing amide content. A mechanism for the reaction is proposed.
Theoretical analysis of two hot water cabinet systems for decontamination of sides of beef
Authors: DAVEY K. R.
Published: July 2010

The theory underlying the use of hot water to reduce the numbers of microbial contaminants of public health significance on freshly slaughtered animals was investigated. An analysis of steady‐state predictions of microbial reductions and accompanying evaporative heat and mass losses in a hot water cabinet for the decontamination of beef sides is developed, based on published correlations. This is more comprehensive than previously undertaken and is used to compare two methods of contacting hot water with the sides of beef: conventional pressure sprays and an alternative, overhead distributor or ‘deluge’ system. Predictions indicate that a distributor cabinet does not need doors or thermal insulation, and highlight the potential economy and practical advantages over conventional spraying.
A laboratory evaluation of a novel hot water cabinet for the decontamination of sides of beef
Authors: DAVEY K. R. , SMITH M. G.
Published: July 2010

A hot water cabinet based on an idealized distributor design for the decontamination of sides of beef is described and a laboratory evaluation of this novel cabinet is reported.

Beef sides were inoculated with E. coli and exposed to mean water temperatures at the surface tissue (Tf) of 83.5, 74.2, 66.0 and 44.5°C for 10 or 20 s. Mean log10 reductions of bacteria for 10‐s exposures were 2.23, 1.40, 0.91 and 0.2. For 20 s, reductions were 2.98, 2.14, 1.17 and 0.1. There was a significant (P < 0.05) linear relationship between log reductions and Tf which varied with exposure time. At a Tf of 83.5°C with exposure times greater than 20 s, carcass bloom was judged to be permanently and adversely affected. At shorter times or with lower temperatures this did not occur.

Evaporative heat losses were well correlated with the pressure driving force (r= 0.89) and gravity driving force (r= 0.92) for air interchange between the cabinet and its surrounds.

The running cost using the distributor cabinet was one‐third of that of an existing spray cabinet when compared at the maximum reduction of log 1.3 (95%) achieved by the spray cabinet. An additional advantage of the distributor cabinet is its constructional simplicity.
Relationship between energies of water sorption and diffusion in grains
Authors: AGUERRE R.J. , SUAREZ C. , VIOLLAZ P. E.
Published: July 2010

The relationship between activation energy for diffusion, ED and the BET heat of sorption, E1, was determined from literature data for maize, rice, sorghum, soybean and wheat and gave ED/E1= 0.5. Given that ED < E1, diffusion was interpreted in terms of a mechanism involving the hopping of water molecules from one adsorption site to another.
Studies on stability of blue grape anthocyanins
Authors: THAKUR B. R. , ARYA S. S.
Published: July 2010

The stability of grape anthocyanins in grape squash and juice is influenced by the nature of packaging materials and preservatives. In grape squash losses were 65–70% in glass bottles, 64–67% in paper‐aluminium foil‐polyethylene (PFP) laminate pouches, 77–81% in polypropylene (PP) pouches and 68–73% in metallized polyester‐polyethylene (MPP) laminate pouches during 60 days storage at 15–35°C. After 60 days, loss of anthocyanins was lower in samples preserved with sorbate than with benzoate, but not after 120 or 180 days storage. Sugar increased losses of anthocyanins, which were more stable in isolated model systems of sugar and benzoate than in grape squash and juice. Anthocyanins were most stable in anhydrous systems, and their rate of degradation progressively increased with water activity.
The effect of a surface coating of table salt of varying grain size on perceived saltiness and liking for paté
Authors: SHEPHERD R. , WHARF S. G. , FARLEIGH C. A.
Published: July 2010

Thirty subjects rated samples of paté with five concentrations of salt for intensity of saltiness and for liking. The samples were made up either with the salt incorporated into the paté or added to the surface as small or large crystals. Intensity was highest for the small crystals on the surface and lowest for the salt in the food. The slope of the psychophysical function was also lower for salt in the food than on the surface and the Weber ratio for the salt in the food was larger. There was no significant difference in the most preferred concentration of salt between samples with the salt in or on the food but overall liking was lower for the latter. These results show that a surface coating will give greater saltiness than the same amount of salt incorporated into the food, but as the surface coated paté samples were less liked, this would not offer a useful means for reducing the amount of salt in the diet.
Substitution of sodium chloride by Morton Lite Salt or Mineral Salt in mayonnaise
Authors: NDABIKUNZE B. K. , LAHTINEN S.
Published: July 2010

The effect of substituting Morton Lite Salt or Mineral Salt for sodium chloride in neutral emulsion and in mayonnaise was evaluated by using 1.00% sodium chloride, 1.25% Morton Lite Salt and 1.40% Mineral Salt of the emulsion weight. None, 1.00%, 2.00% and 3.00% of lactose were used to mask the bitter taste associated with potassium chloride. A triangle test using twelve to fifteen panelists was used. Results indicated that both Morton Lite Salt and Mineral Salt had a significant different taste (P≤ 0.01) as compared with sodium chloride when they were used with none and 1.00% of lactose. Samples which had 2.00% or 3.00% lactose showed no significant taste difference between Morton Lite Salt or Mineral Salt and sodium chloride. It was concluded that a bitter masking agent such as lactose is needed when Morton Lite Salt or Mineral Salt is used to substitute sodium chloride in mayonnaise.
Chickpea, mungbean, cowpea and peanuts as substitutes for soybean curds
Authors: MOHAMED S. , JOHAN Z. , BAKAR J.
Published: July 2010

Acceptable beancurds could not be formed from chickpea, mungbean, cowpea and peanuts, when using the standard procedure used to make soybean curds. Firmness (rigidity) of the curd was proportional to the protein content; inversely proportional to the square of the starch content; and negatively correlated with the square of the fat content. Firmness also improved the taste of the curds. Satisfactory curds could be formed from legume sources other than soybean only after the partial removal of starch (in chickpea, mungbean and cowpea) or oil (in peanuts). Calcium sulphate was the best coagulant; optimum concentrations were 0.3% (0.02 M) of the milk; and optimal heating time was 15 min at 95°C. Stirring during coagulation aided formation of firmer gels. The rigidity moduli of the various curds were: soybean 51 000 N m−2; peanuts 2200 N m−2; chickpea 6000 N m−2; mungbean 11 000 N m−2; and, cowpea 29 000 N m−2. Chickpea and mungbean curds were rated as liked (2.0 and 1.8 respectively), almost as well as soybean curds (1.5); cowpea (3.1) and peanut (4.2) curds were less preferred.
Deacidification of passion fruit juice by ultrafiltration and ion‐exchange processes
Authors: LUE S. J. , CHIANG B. H.
Published: July 2010

Deacidification of passion fruit juice by a combination of ultrafiltration (UF) and ion‐exchange was studied. Prefiltering the juice by UF facilitated the ion‐exchange process. At a feed rate of 700 ml h−1, weakly basic resins removed nearly 95, 80 and 50% titrat‐able acids from five, seven and twelve bed volumes of UF permeate, respectively, and did not cause significant sugar losses. UF retentate can be added back to the deacidified UF permeate to restore the suspended solids and some flavour components.
Sub‐ambient differential scanning calorimetry of lard and lard contaminated by tallow
Authors: KOWALSKI B.
Published: July 2010

DSC scans of lard, cow tallow and admixtures were determined by cooling from 70 to −50°C. Analysis of the thermograms indicated that tallow could be detected in lard at concentrations above 1%, although the relative error of determination was large. For mixtures with tallow contents in the range of 6–26%, the relative error in the estimation of tallow content was in the range of 10–1%, respectively.
Fractionation of water insoluble solids and extraction of pectins from residues of juice‐extracted satsuma mandarin fruit by wet grinding
Authors: FUJIO Y. , FURUTA S.
Published: July 2010

The waste biomass residue from satsuma mandarin juice production was extracted by wet‐fine grinding and separated by centrifugation into insoluble and soluble fractions. The insoluble material was wet‐screened into four fractions and analysed for crude fibre and total hydrolysable sugars. Crude fibre was almost exclusively in fractions containing particles over 50 μm, comprising about 65% of the insoluble material; this could provide a raw material high in crude fibre. The remaining insoluble fraction was almost devoid of crude fibre.

The soluble extract contained up to 63% of the total pectic substances with very similar methoxyl contents and degree of esterification, but double the viscometric molecular weight of a standard citrus pectin. The method provides an alternative to that of hot acid extraction.
The effect of cholesterol content of phospholipid vesicles on the encapsulation and acid resistance of β‐galactosidase from E. coli
Authors: MATSUZAKI M. , McCAFFERTY F. , KAREL M.
Published: July 2010

β‐Galactosidase was encapsulated in lecithin‐cholesterol liposomes prepared by dehydration‐rehydration (DR) and reverse‐phase evaporation (RE). In both methods, the encapsulation efficiency decreased as cholesterol content increased. Enzyme activity was determined to be located both on the surface and in the interior of the vesicle. When the enzyme‐loaded vesicles were exposed to acidic buffer solution, the activity on the surface of the vesicle was rapidly lost. The enzyme in the interior of the vesicle was more acid‐resistant. The residual activity of enzyme depended on the molar ratio lecithin: cholesterol (L:C ratio). In both methods, the vesicles which showed the greatest acid resistance were those with an L:C molar ratio of 1:3. These vesicles retained their enzymatic activity and acid resistant character after 1 month storage at 5°C under nitrogen.
Kinetics of acid‐catalysed de‐esterification of pectin in a heterogeneous medium
Authors: KIRTCHEV N. , PANCHEV I. , KRATCHANOV CHR.
Published: July 2010

The rate constants of acid‐catalysed de‐esterification at 30,40 and 50°C of apple, lemon, grapefruit, orange and carrot pectins, in ethanolic hydrochloric acid show that the reaction is a pseudo first‐order reaction and is uninfluenced by the origin of the pectin.

The activation parameters (ΔS*= ‐107.2±2.6 J mol‐1 K‐1; ΔH*= 74.51±0.96 kJ mol‐1) were close to those calculated by Speiser, Eddy and Hills (1945) for homogeneous acid de‐esterification of apple pectin, and thus the reaction mechanism appears to be the same as that in solution.

In most cases, (except grapefruit pectin) gel strength increased with the degree of es‐terification and the duration of acid treatment: the maximum depends on the type of the pectin.
Starch gelatinization temperatures within potato during blanching
Authors: LAMBERG INGRID , OLSSON HELGOT
Published: July 2010

The progression of gelatinization within potato cylinders blanched at 65,75 and 85°C for 2, 4 and 6 min was followed by iodine staining of sections. The distance to the gelatinization front was measured on photographs of both blanched and stained potatoes. A time‐temperature simulation was performed with a finite difference computer program using thermal conductivity, specific heat, phase transition, density, heat‐transfer coefficient, and initial temperatures as input data. Measured distances were used to determine the simulated temperature at the gelatinization front. The computer‐simulated temperatures used to determine the gelatinization temperature within blanched potato were in good agreement with published values.
Rice bran‐soy blends as protein supplements in cookies
Authors: JAMES C. , COURTNEY D. L. D. , LORENZ K.
Published: July 2010

The effect of incorporating one of three stabilized full‐fat rice brans in combination with each of four soy ingredients in a sugar‐snap cookie was investigated. The four soy ingredients in a sugar‐snap cookie were two soyflours (full‐fat and defatted), a soy concentrate and a soy isolate. Rice bran and soy were added in place of wheat flour to increase protein content from 6% to a minimum of 9%, and the cookies were compared with each other and with a 100% wheat flour cookie. Quality characteristics evaluated included protein, spread, physical texture and colour, and sensory preference by ranking for colour, crispness and flavour. In general, the rice bran‐soy cookies had less spread (even with added shortening, water and emulsifier), were less crisp and more chewy, and were somewhat darker in colour than the 100% wheat flour cookie. The soy isolate, USDA and Protex 20‐S cookies were as acceptable in colour, crispness and flavour as the control.
Effect of temperature (0–80°C) on the interior reflectance of ovine sternomandibularis muscle
Authors: SWATLAND H. J.
Published: July 2010

Reflectance spectra (400–800 nm) were obtained from the interior of ovine sternomandibularis muscle as temperatures changed between 0 and 80°C by means of optical fibres. Between 0 and 40°C, no significant changes were detected, but between 25 and 80°C reflectance increased (P < 0.001). The temperature coefficient of reflectance (slope/mean) reached maxima at 440 nm (0.065 °C‐1) and at 560 nm (0.039 °C‐1), but was fairly uniform for much of the remainder of the spectrum (0.028 °C‐1). Reflectance started to increase at about 35°C, and decreased between 70 and 80°C. Little evidence for the loss of red and the appearance of brown pigments was detected from estimates of chromaticity coordinates x and y. The major effect of cooking was to increase light scattering (opacity).
Enzyme induced loss of sucrose in berry fruit juices
Authors: PLOWMAN J. E. , LOVE J. L. , HERBERT B. R.
Published: July 2010

Varied concentrations of sucrose have previously been reported in freshly picked berry fruits. We have observed that sucrose in juice extracts from berries decreased markedly with time. The loss of sucrose added to raspberry and loganberry juice is attributed to the action of the enzyme, invertase. Heat inactivation immediately after picking reduced the loss of sucrose in raspberries and blackberries. Knowledge of these changes might influence the methods of harvesting, storage and processing.
Effect of heat on the fatty acids and aldehydes of veal meat phospholipids
Authors: FOGERTY A. C. , WHITFIELD F. B. , SVORONOS D. , FORD G. L.
Published: July 2010

Reactions involving phospholipids contribute considerably to the flavour and aroma of cooked meat. The effect of heat on the fatty acids and fatty aldehydes of phospholipids from veal was studied using aqueous model systems wherein extracted phospholipid fractions were heated in the presence or absence of ribose or glycine. After 1 h at 132°C, ethanolamine‐containing phospholipids rapidly lost most of their component aldehydes but not their fatty acids, whereas choline‐containing phospholipids lost their aldehydes much more slowly. In both cases, the presence of ribose or glycine had little effect on the loss of aldehydes. In the meat itself, after heating at 132°C, there was a 90% loss of aldehydes which was similar for both the ethanolamine‐ and choline‐containing phospholipids, but the latter lost fatty acids more slowly than the former.