bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of starches on the heat stability of milk
Authors: TZIBOULA ATHINA , MUIR D. DONALD
Published: July 2010

Starches from different botanical sources have been added (0.5–1.5% w/w) to skim milk and pregelatinized by heating at 70°C for 30 min. the heat coagulation time (HCT) of the milk‐starch mixtures was then evaluated at 140°C. the addition of native starches to milk had a destabilizing effect. Increasing the concentration of added starch caused a decrease in HCT's. the reduction in the heat stability of milk proteins was not related to the amylose/amylopectin composition or to the granular structure of the starches. Modification of the molecular properties of the starch components by acid hydrolysis or cross‐linking resulted in an enhancement of the heat stability of the mixtures.
NMR assessment of water uptake in different Vigna spp. seeds
Authors: MARCONI EMANUELE , CARNOVALE EMILIA , NOLA ALFREDO DI , BROSIO ELVINO
Published: July 2010

Water uptake in seeds of ten wild and cultivated Vigna spp. accessions was investigated by NMR Spectroscopy. Water absorbed by the intact seeds was measured at intervals by changes in unabsorbed water using analysis of transverse magnetization decay of water protons. Widely different hydration kinetics of first and higher orders were found amongst the samples. the time required to reach saturation hydration capacity ranged from 3 to 16 h; total amount of absorbed water varied from 1.06 to 1.39g H2O g−1 sample and kinetic constant from 8.2 to 20.4 10−3 min−1.

Accessions with a rough seed coat showed a fast water uptake within the first hour while some accessions smooth seed coat need an activation period of 1–5h.

No significant relationships were found between kinetic constant, absorbed water and protein content or some morphological characteristics (100 seed mass, length/width, width/thickness).

Wild species did not absorb water for days, an attribute related to biological survival, but after dehulling they absorbed water at similar rates to the cultivated cowpeas.

NMR can be a suitable technique to investigate some technological characteristics of legumes related to domestic and industrial processing (cooking, canning). It has potential to give data on the various forms of free and bound water, although this was not fully derived in the present work.
Development and nutritional quality evaluation of weaning foods based on malted, popped and roller dried wheat and chickpea
Authors: LIVINGSTONE ANNIE S. , FENG JIAN J. , MALLESHI NAGAPPA G.
Published: July 2010

Optimal conditions for malting wheat and chickpea for preparation of weaning foods were standardized and malted flours from 48 h germinated wheat and 24 h germinated chickpea were blended to prepare malted weaning food. Wheat was dry‐heat‐parboiled (bulgurized), popped in hot sand and blended with popped chickpea flour to prepare popped weaning food. Mildly toasted and debranned wheat and dehusked chickpea flours were mixed and the blend was roller‐dried for preparation of roller dried weaning food. the formulations had 60% wheat, 30% chickpea, 5% skim milk powder and 5% sucrose and contained about 16% protein. the cooked paste viscosity (dietary bulk) of malted food, popped food with malt, and roller dried food with malt was significantly lower than popped and roller dried foods at all comparable slurry concentrations. the energy density of malted and malt‐added food slurries at spoon feeding consistency was 4.2 KJg−1. PER (2.91), biological value (88.3) and true digestibility (87.5) values of malted food were higher than that of the other formulations.
Electron paramagnetic resonance of gamma‐irradiated cellulose and lignocellulosic material
Authors: DEIGHTON N. , GLIDEWELL S. M. , GOODMAN B. A. , MORRISON I. M.
Published: July 2010

The detection by electron paramagnetic resonance (EPR) spectroscopy of free radical centres trapped in cellulosic materials has been proposed as a potential method for the identification of irradiated foodstuffs of plant origin. However, the published spectra of irradiated cellulose show distinct differences from those obtained from unpurified cellulosic materials. In an attempt to explain these differences we have carried out a detailed investigation of the EPR spectra of gamma‐irradiated celluloses and of the products from a lignocellulosic material (oat straw) that had been subjected to various chemical treatments. We conclude that chemical treatments of cellulosic material involving strong alkali (15% in the present measurements) during purification result in subtle structural alterations which produce a different chemical environment for the unpaired electron that is trapped on irradiation.
Modified atmosphere packaging of common mushroom
Authors: LOPEZ‐BRIONES GUADALUPE , VAROQUAUX PATRICK , BUREAU GILBERT , PASCAT BERNARD
Published: July 2010

Until recently, the films used for packaging fresh fruits and vegetables were not permeable enough to balance the high respiration rate of mushrooms. Consequently, modified atmosphere packaging (MAP) in sealed pouches or punnets was not appropriate for this commodity. Four microporous films in oriented polypropylene (OPP) and one film currently used to overwrap mushroom punnets (stretchable PVC) were tested. Mushroom punnets placed into pouches were stored at 4 and 10°C for 8 days. the influence of the modified atmosphere on the marketing quality of pre‐packed mushrooms was assessed by measuring the external and internal colour, development stage, firmness and microbial growth. A mathematical model was used to predict the gas composition within the pouches at steady state as a function of the film properties and the characteristics of the plant tissues. the equation calculated from the simplified model shows a linear relationship between the reciprocal of O2 concentration at steady state, (1/x) at 10 and 4°C and the reciprocal of the film permeability, (1/PmO2).
The effect of cask charring on Scotch whisky maturation
Authors: CLYNE JANICE , CONNER JOHN M. , PATERSON ALISTAIR , PIGGOTT JOHN R.
Published: July 2010

The developing chemical composition and aroma attributes of whisky distillates maturing in uncharred and charred American oak casks were compared at intervals over a total maturation period of 3 years. Chemical variables were selected to encompass a wide range considered to contribute to the flavour of maturing distillate. Descriptive sensory analysis was used to generate detailed sensory profiles which were very different for the charred and uncharred cask samples throughout the maturation period. the charred cask samples were rated significantly higher for terms characteristic of mature distillates and significantly lower for terms characteristic of immature distillates. There were significant differences in syringaldehyde, conifer‐aldehyde, sinapaldehyde, vanillic acid, total phenols and absorbance between the charred and uncharred cask samples but these differences did not completely account for the changes in sensory characteristics.
Microbicidal effect of hydrostatic pressure on satsuma mandarin juice
Authors: TAKAHASHI YASUO , OHTA HIDEAKI , YONEI HIROSHI , IFUKU YASUSHI
Published: July 2010

Six microbial strains were inoculated into Satsuma mandarin (Citrus unshiu Marc.) juices and the effects of hydrostatic pressure on their viability were examined. Five micro‐organisms were substantially inactivated under 400 MPa at room temperature for 5 min whereas B. subtilis survived. the effects achieved by treating at 57°C under 100 MPa for 5 min were comparable to those achieved by treating under 400 MPa at room temperature for 5 min. Pectin esterase was not inactivated even after treating at 600 MPa and 57°C for 5 min. Although the high pressure treatment exerted hardly any effect on juice chemical components, the pulp particle size distribution was slightly changed by treating under 600 MPa at room temperature for 30 min. Pressure treatment had little effect on the volatile flavour components.
Yoghurt whey medium for food‐borne yeasts
Authors: YAMANI MOHAMMED I.
Published: July 2010

A selective medium based on yoghurt whey was developed for the enumeration of yeasts in foods. Yoghurt whey agar (YWA) was prepared by mixing one part of a sterile agar solution (5%) with two parts of a sterile whey filtrate obtained from autoclaved (121°C, 20min) plain set yoghurt. the performance of YWA in the enumeration of yeasts was compared with that of plate count agar plus antibiotics (APCA) and acidified potato dextrose agar (PDA‐A) by examining food samples and broth cultures of known yeast isolates. APCA ranked first, confirming the superiority of antibiotic amended media over the acidified ones. the overall performance of YWA was comparable to that of PDA‐A.
Temporal patterns of nasal, oral, and retronasal perception of citral and vanillin and interaction of these odourants with selected tastants
Authors: KUO YU‐LING , PANGBORN ROSE MARIE , NOBLE ANN C.
Published: July 2010

Perceived intensities of aqueous solutions of 0.01% citral (C) and of 0.14% vanillin were estimated over time when presented nasally (sniffing), retronasally (sipping) and orally (sipping with nose pinched). the onset and decay of nasal perception was very rapid, with maximum intensity reached between 4‐8s and extinction between 9‐15s. the oral response was extremely low, while retronasal intensity reached maximum 11‐19 s after stimulation with a duration ranging from 40 to 120s. Orally, 10 of 19 subjects rated solutions containing C and citric acid (CA) significantly higher than those containing CA alone. Retronasally, citral intensity was enhanced by CA > CA + sucrose (SUC) > SUC > NaCl. Addition of xanthan gum had little effect on perception of citral. Retronasal intensity of vanillin solutions was increased by addition of sucrose (SUC) and depressed by CA and by NaCl. the results demonstrated large differences in perceived intensity and duration via the three procedures, significant alteration of oral intensity by added tastants, and marked bimodality of response upon the addition of acid to citral.
Moisture diffusivities of sunflower seed components
Authors: ROVEDO CLARA O. , AGUERRE ROBERTO J. , SUAREZ CONSTANTINO
Published: July 2010

A diffusion‐based drying model has been used to separately model the thin‐layer drying of sunflower kernel and whole seed. the diffusivity of kernel was determined by means of the analytical solution of Fick's second law. the drying of whole seed was simulated by means of the numerical solution of Fick's second law for a two‐composite solid. Kernel and hull diffusivities were determined at 40° and 50°C and air velocity of 15ms‐1, using the theoretical curves that best fit the data. the diffusivities of kernel were 7.1 x 10‐6 cm2s‐1 and 1.7 x 10‐6cm2s‐1, and of the hull 1.7 x 10‐6cm2s‐1 and 7.1 x 10‐6cm2s‐1 for the respective temperatures of 40° and 50°C.
Sensory, microbiological and chemical changes in hoki stored in ice
Authors: RYDER JOHN M. , FLETCHER GRAHAM C. , STEC MARGERET G. , SEELYE RICHARD J.
Published: July 2010

Sensory, physical, microbiological and chemical analysis were carried out on whole hoki during 21 days of storage in ice. Sensory results show that cooked hoki developed unpleasant odours and flavours after 11 days. Texture changes in cooked fish were minimal. Assessment of the raw fish provided a useful means of predicting quality of cooked fish. the total viable aerobic count on the fish surface first exceeded ICMSF standards after fish had been stored for 11 days in ice. Hypoxanthine and K value were good objective indicators of the freshness of hoki, while measurement of trimethylamine provided a means to monitor the onset of spoilage.
Extension of shelf‐life of chilled sliced roast beef by carbon dioxide packaging
Authors: PENNEY NICHOLASS , HAGYARD CEDRIC J. , BELL R. GRAHAM
Published: July 2010

Commercially prepared sliced roast beef in conventional vacuum and oxygen‐free saturated carbon dioxide controlled atmosphere packs was stored at + 10°C + 3°C and ‐ 1.5°C. the development of foreign flavours during chilled storage resulted in product rejection before the development of putrid flavours characteristic of overt microbial spoilage. the nature of these foreign flavour elements reflected the qualitative composition of the microflora developing on the roast beef slices with ‘sharply acidic’ associated with Lactobacillus‐domimted flora and ‘sweaty’ occurring when these flora, contained significnat numbers of Brochothrix thermosphacta. Product in vacuum packs was rejected on sensory criteria by a trained panel after 3 days, 3 weeks and 8 weeks for storage at + 10°C, + 3°C and ‐ 1.5°C, respectively. At these temperatures, in oxygen‐free saturated carbon dioxide controlled atmosphere packaging, rejection levels were not attained after 4 days, 10 weeks and 16 weeks respectively.
The effects of temperature and moisture content on lipid peroxidation during storage of unblanched salted roasted peanuts: shelf life studies for unblanched salted roasted peanuts
Authors: EVRANUZ E. ÖZGÜL
Published: July 2010

The effects of temperature and moisture content on fat oxidation (peroxide value) during storage of commercial unblanched salted roasted peanuts were investigated by storing 1.4 ±0.02% moisture samples at 15°C, 25°C, 35°C and 1.4 ± 0.02%, 2.2 ± 0.04%, 2.86 ± 0.03%, 3.9 ± 0.06% moisture samples at 35°C. Oxidation took place even at low temperatures and the rate of oxidation was especially accelerated at high temperatures. the Q10 value for peroxidation was calculated as 1.60 from the shelf‐life plot (r= 0.821).

The accelerated shelf life test at various moisture contents showed rate of peroxide formation is decreasing near or above BET monolayer value, 2.13%, calculated from the BET equation (r= 0.997) and then increasing with further increase in moisture content. In order to prevent the loss of desirable crispness of the product BET monolayer value is proved to be the most suitable for extending shelf life.
Dynamics and variability of bacterial population density on leaves of field‐grown endive destined for ready‐to‐use processing
Authors: MORRIS CINDY E. , LUCOTTE THÉRÈSE
Published: July 2010

To quantify the variability and dynamics of bacterial populations on field‐grown broad‐leaved endive (Cichorium endivia cv. Samy) destined for ready‐to‐use processing, plants were sown at three dates in 1990 for cultivation during the autumn season in southern France. Densities of populations of total, fluorescent pseudomonad and pectolytic bacteria were determined for entire seedlings in the greenhouse and for outer and inner leaves of plants in the field throughout the season until harvest. On seedlings from the greenhouse, bacteria were always detected but fluorescent and pectolytic bacteria were only sporadically detected and generally composed less than 0.1% of the total population. In the field there were significant differences in total, fluorescent and pectolytic bacterial populations on outer and inner leaves, among different plants of the same age, and among inner leaves sampled at the three different dates of harvest. the variability observed suggests that it is reasonable to pursue development of cultural or industrial sorting methods to reduce the microbial load of endive destined for ready‐to‐use processing.
Effect of temperature on sorption isotherms and heats of sorption of quince jam
Authors: SÁ M. MANUEL , SERENO ALBERTO M.
Published: July 2010

The water sorption isotherms of two different brands of ‘marmelada’ quince jam at different temperatures were determined experimentally and the parameters for the GAB estimated.

Results obtained showed that the typical high sugar content of these products leads to an inversion of the usual temperature‐dependence of water sorption isotherms for values of water activity above 0.6. This confirmed a behaviour already reported by other authors for high sugar products (e.g. dried fruits).

From the data obtained for each brand of Portuguese ‘marmelada’ at different temperatures it was also possible to estimate net isosteric heats of sorption and their dependence on moisture content.
Enhanced diffusion during the electrical heating of foods
Authors: SCHREIER PAUL J.R. , REID DONALD G. , FRYER PETER J.
Published: July 2010

Betanin effusion from beetroot was greater during 50 Hz electrical heating than during conventional heating. the rate of loss is proportional to surface area and is a linear function of the applied RMS electric field. the surface area dependence was confirmed with solutions of the dye Rhodamine B held in semipermeable tubing. It was calculated that at 50 Hz the relaxation time of the atmosphere around an ion is significantly less than the period of the voltage, so that it is likely that ions will respond to the electric field. Possible consequences for other small ionizable food components during electrical heating are discussed.
Influence of processing regime on certain characteristics of diffusionally extracted apple juice
Authors: LEACH GARETH , SCHOLS HENK , PYLE LEO , NIRANJAN KESHAVAN
Published: July 2010

The composition of apple juices produced by diffusional extraction under different processing regimes was investigated. It was demonstrated that the viscosity characteristics of a juice are dependent on the amount and nature of its pectic substances. With the exception of the addition of a pectin‐degrading enzyme, the juice viscosity was most strongly dependent on the degree of esterification of the juice pectin and was also affected by the presence of calcium ions. the degree of esterification of the pectin, and hence the juice viscosity, could be manipulated by changing the process temperature or by changing the residence time in the extractor.
Formaldehyde instead of dimethylamine determination as a measure of total formaldehyde formed in frozen Argentine hake (Merluccius hubbsi)
Authors: BOERI RICORDO L. , ALMANDÓS MARIA E. , CIARLO ALICIA S. , GIANNINI DANIEL H.
Published: July 2010

The relationship between dimethylamine (DMA) and formaldehyde (FA) contents of fillet and minced flesh of hake (Merluccius hubbsi) during frozen storage was analysed. the relation is clearly linear and independent of the type of product and storage temperature. As the intercept was nearly zero, a constant relation between FA and DMA was established, with both similar as keeping time predictors. Measuring FA content by the chromotropic acid method was equivalent to, but easier than measuring DMA content.
Effects on Scotch whisky composition and flavour of maturation in oak casks with varying histories
Authors: PIGGOTT JOHN R. , CONNER JOHN M. , PATERSON ALISTAIR , CLYNE JANICE
Published: July 2010

Scotch whisky distillates in casks with different histories, but typical of those used in industrial practice, were compared by chemical and sensory methods over the first 3 years of maturation. Analysis by capillary gas chromatography showed differences in wood‐derived components, and analysis of non‐volatile and less‐volatile compounds by HPLC showed clear changes with maturation time, and differences between casks. Descriptive sensory analysis showed changes associated with the early stages of maturation, and some differences between casks. Sensory descriptor scores associated with wood‐derived materials (spicy, smooth, vanilla, woody) were modelled on data from non‐volatile compounds using partial least squares regression.
Tenderization of spent fowl drumsticks by marination in weak organic solutions
Authors: KIJOWSKI JACEK , MAST MORRIS G.
Published: July 2010

Drumsticks from spent layer hens marinated in 2% NaCl brine for 72 h to improve ‘tenderness’ as measured by shear‐force, showed reduction of 40% of shear force of the meat. Marinating in 1.5% lactic or acetic acid for 72h reduced shear‐force of the M. gastrocnemius by 21.7‐fold and 8.1‐fold, respectively to values comparable to those observed for broiler chicken drumstick meat. the presence of NaCl in lactic or acetic acid marinating solutions reduced the effect. Lower acid concentration (0.5%) in brine and the shorter time of marination (36 h) produced less change. Vacuum tumbling of drumsticks in lactic or acetic acid with 2% NaCl for 2 h reduced the shear values of drumstick M. gastrocnemius by ∼50%, but longer periods had no further effect. Neutralization of the acidic taste of marinated drumstick meat with corresponding salts of the acids (1.5% sodium lactate or sodium acetate or sodium bicarbonate) reversed the change to an extent dependent on the type of salt used and change in pH level.
The quality of surimi made from Threadfin bream stored on ice for different periods
Authors: YEAN YU SWEE
Published: July 2010

Surimi gels prepared from Threadfin bream (Nemipterus tolu) stored on ice for up to 8 days showed no significant differences in protein, fat, and moisture contents, but the yield decreased significantly after 2 days. Protein losses increased, but not significantly. Gel strength (hardness) was still acceptable after 2 days on ice, but then declined rapidly to unacceptable by 4 days on ice. N. tolu should not be kept on ice for more than 2 days for production of surimi of acceptable quality.
Modelling of the total water desorption rate from packaged moist food
Authors: DESOBRY STÉPHANE , HARDY JOËL
Published: July 2010

This study deals with the modelling of total water desorption rate (TWDR) from moist food in multilayer packaging. the TWDR determination method is based on water content variations of an open or wrapped agar gel simulating high moisture content food (Camembert cheese). the packaging studied, widely used in the French cheese industry, is composed of three interacting layers (wax, paper, varnish). First, a simple paper was studied with different quantity of wax (0‐6 gm‐2). Then, various quantities of varnish (from 0‐45 gm‐2) were layered on the waxed paper. the interactions between all the packaging components and their effects on TWDR are shown and explained. the method allows calculation of the apparent water diffusivities, the water concentration and the water activity at each point in the packaging from Fick's and Henry's laws and water sorption isotherms. A model of water vapour transport from the centre of a moist food to atmosphere through the wrapping materials is proposed and validated.
Sensory attributes and acceptance of sucrose and fat in strawberry yoghurts
Authors: TUORILA HELY , SOMMARDAHL CAMILLA , HYVÖNEN LEA , LEPORANTA KALLE , MERIMAA PIRJO
Published: July 2010

Yoghurts containing approximately 0.1, 1.5, 3.2, or 5.2% dairy fat were sweetened with 6, 8, 10, or 12% sucrose and flavoured with strawberry jam. the sweetness, fattiness, and sourness of the resulting 16 samples were rated by a laboratory panel (n= 14), and the hedonic responses by a consumer panel (n= 41). As expected, the sweetness and fattiness increased with increasing sucrose and fat contents, respectively. Sucrose enhanced perceived fattiness and fat enhanced sweetness. Sourness was suppressed by both. the sample with 10% sucrose and 3.5% fat received the highest, and the samples with the lowest sucrose and fat contents the lowest, pleasantness ratings. Among the consumers, men preferred high sweetness and fattiness and low sourness, but women did not show any definite tendencies. Although the consumer panel was small, the results demonstrate the importance of segmenting consumers to predict product success.
Processing of the fruit of five prickly pear cultivars grown in South Africa
Authors: JOUBERT ELIZABETH
Published: July 2010

In tests of processing five cultivars of prickly pear fruit, lye‐peeling was not effective as peel was partially removed and flesh erosion occurred. When hand peeled fruit were canned in acidified sucrose syrup (20°B) at 100°C for 15min, differences between cultivar firmness were observed; fruit firmness decreased with increasing processing time, but increased on addition of 0.25% CaCl2 to the syrup. Canned fruit stored for 22 months were still firm and retained their shape, but yellow to orange colour cultivars lost much of their colour by loss of indicaxanthin. the canned fruit developed a gherkin jam‐like uncharacteristic flavour. Fruit yielded between 55% and 68% edible portion which contained 65‐76% turbid juice with a soluble solids content of 10‐14%. the peel contained approximately 10% soluble solids and 4% sugar, mostly fructose and glucose. Pectin methylesterase activity differed slightly between cultivars.
Effect of heat treatment on the quality of onions during long‐term tropical storage
Authors: THAMIZHARASI V. , NARASIMHAM P.
Published: July 2010

Onion bulbs (cv. Nasik red) were exposed to hot air currents prior to storage to curtail storage losses. Treatments at 80°C for 30min or 60°C for 1 h resulted in heat damage while temperatures of 60°C for 30min or 50°C for 3h or 40°C for 48 h did not cause any heat damage to the bulbs.

A commercial lot treated at 47, 50 or 53°C for 3h and another commercial lot treated at 47 or 50°C for 2‐5 h, were stored for 4 or 5 months in ventilated polyethylene bags at (1) ambient conditions 20‐30°C, RH 50‐80%, and (2) 21 ± 1°C, RH 60‐65%. In general the treated lots had more marketable bulbs, with less incidence of Aspergillus niger infection than untreated controls. Factorial experiments using temperatures 47, 50, and 53°C with durations of treatment between 2 and 5 h revealed that the temperature and duration of heat treatment had a significant effect on the yield of good bulbs and reduction in microbial spoilage during storage. Treatment at a temperature from 47 and 50°C for a duration between 2 and 4 h gave best results when stored at 21 ± 1°C. the effect of treatment lasted up to 3 months in storage.
Stability of cod (Gadus morhua L.) surimi processed with CaCl2 and MgCl2 added to the wash water
Authors: OFSTAD RAGNI , GRAHL‐MADSEN ELISABETH , GUNDERSEN BJØRN , LAURITZEN KRISTIN , SOLBERG TERJE , SOLBERG CHRISTEL
Published: July 2010

Washing cod mince in water containing both CaCl2 and MgCl2 improves the functional properties of the resultant surimi. Gel strength, frozen shelf‐life, and colour, important quality factors for the further processing of surimi, were measured after different heat setting regimes for surimi pastes prepared with or without CaCl2 and MgCl2 addition. the surimi was stored frozen for up to 12 months. the positive effect of setting at low temperatures was far more pronounced when the surimi was processed with 7.5 mM CaCl2 and 15 mM MgCl2 added to the wash water. After 12 months of frozen storage, the gel strength of the salt‐washed surimi was reduced, but was still higher than the control. the lightness of the cooked surimi model product was reduced when salt‐washed. the positive effect of the ions was abolished when lysine, an inhibitor of transglutaminase, was included. Hence, the positive effect of Ca2+ and Mg+2 ions on the functional properties of surimi may be caused by a transglutaminase‐type enzyme present in cod mince.
Influence of genetic strain, pH, and salts on cooking properties of processed light and dark broiler meat *
Authors: XIONG YOULING L. , PESCATORE ANTHONY J. , CANTOR AUSTIN H. , BLANCHARD SUZANNE P. , STRAW MARK L.
Published: July 2010

The cooking yields of ground breast (light) and thigh (dark) meat of eight genetic crosses of commercial strains were compared using different pre‐cooking treatments. Adjustment of fresh meat pH from 6.0‐6.1 to 6.4 with 0.5% phosphate increased (P < 0.05) the average cooking yield of processed breast meat from 90 to 93%, and of thigh meat from 79 to 82%. Addition of 2.5% sodium chloride to the ground meat further improved the cooking yield. Most genetic crosses of broilers differed significantly (P < 0.05) in meat cooking yield, which changed similarly with pH and salt adjustments in most strains. Cooking yields of control, pH‐adjusted and saltadded thigh meats were positively correlated with each other, but little correlation existed between thigh and breast meats. the results show the influence of genetic cross on meat cooking yield, and indicate the importance of controlling pH and salt content in broiler meat processing.
Carbon dioxide controlled atmosphere packaging of sliced ham
Authors: BOEREMA JAQUELINE A. , PENNEY NICHOLASS , CUMMINGS TRACEY L. , BELL R. GRAHAM
Published: July 2010

Commercially produced sliced, cooked, reformed ham in vacuum and carbon dioxide packs was stored at 10, 3, and ‐1.5°C. After various periods three vacuum and three carbon dioxide packs from each temperature were removed from storage and subjected to microbiological and sensory evaluation. Under mildly abusive chilled storage (10°C), the use of carbon dioxide in packs offered no advantage over vacuum in respect of retarding either microbial growth or the onset of unacceptable flavour changes. At chilled storage temperatures (3 and ‐1.5°C), carbon dioxide packaging significantly extended the lag phase before microbial proliferation commenced, but did not extend the acceptable organoleptic life of the sliced ham beyond that attained using vacuum. the use of carbon dioxide controlled atmosphere packs cannot be advocated to replace the current use of vacuum packs for sliced, cooked, reformed ham, in terms of extending product storage life.
Effect of dough ingredients on apparent viscosity and properties of extrudates in twin‐screw extrusion‐cooking
Authors: WANG S. , CASULLI J. , BOUVIER J.M.
Published: July 2010

A capillary‐type viscometer was used in a twin‐screw extruder to measure the apparent viscosity of cooked‐extruded wheat‐flour dough with various ingredients: lecithin, palm oil, sucrose, whey, sodium chloride, and bran. the effects of concentration of these ingredients on dough rheology and physical properties of extrudates (apparent density, expansion ratios, mechanical, and crispness properties) were measured. the role of ingredients was discussed in terms of their physico‐chemical effect on biopolymer conversion. the correlations between apparent viscosity of dough and physical properties of extrudates were developed.
Effect of freezing rate and xanthan gum on the properties of corn starch and wheat flour pastes
Authors: FERRERO CRISTINA , MARTINO MIRIAM N. , ZARITZKY NOEMI E.
Published: July 2010

The effects of freezing rate on exudate production, rheological behaviour, ice crystal size, and starch retrogradation of corn starch and wheat flour pastes (10% w/w) with and without xanthan gum (0.3% w/w) were studied by means of capillary suction, rotational viscometry, indirect microscopy, and differential scanning calorimetry (DSC).

Higher freezing rates preserved textural characteristics and produced less exudate. In corn starch pastes, rates <1 mm h‐1 caused a marked spongy structure, undesirable for a sauce‐like product, but only a slightly spongy structure in wheat flour pastes. Xanthan gum addition maintained the smoothness characteristic of the unfrozen pastes, avoiding amylose retrogradation. However, effects on ice crystal formation and amylopectin retrogradation were not observed. Although high freezing rates are mostly recommended, low levels of xanthan gum maintained quality characteristics even at low freezing rates, decreasing equipment cost.
Storage stability of concentrated soymilk: evaluation of cowmilk concentrate and salts’ addition and soybean acid‐steeping
Authors: NSOFOR LESLIE M. , UZUEGBU D.N. , CHUKWUMA A.K. , UDECHUKWU A.
Published: July 2010

This paper reports the evaluation of the tropical storage time and stability of sterilized (121°C, 15 min) concentrated soymilk to which cowmilk concentrate, sodium dihydrogen phosphate and trona (a crude alkaline salt) have been added. the effects of acid‐steeping of soybeans on stability of heat‐processed soymilk were also compared with those of blanching and alkali‐steeping.

The addition of skim‐milk concentrate doubled the soymilk coagulation time (stability). Addition of phosphate produced instant coagulation of soymilk after sterilization, whilst combination with trona extended soymilk coagulation time to 30h. Steeping with hydrochloric acid or blanching reduced coagulation time to one third of that with alkali‐steeping. the longest coagulation time (280 h) was produced by a combined alkali‐steeping and simmering treatment. Soymilk pH decreased on coagulation. Destabilization of concentrated soymilk by added phosphate salt is a reversal of the known stability it confers on evaporated milk.
Fortification of maize tortilla with alkali‐treated chickpea flour
Authors: BARRÓN JESUS M. , ESPINOZA ARMIDA
Published: July 2010

Critical parameters for the preparation of alkali‐treated chickpea (Cicer arietinum var. Surutato‐77) flour were studied. the alkali‐treated chickpea flour was used to fortify a commmercial maize flour for tortilla preparation. Fortification levels were set at 5, 10, 15, 20, and 25% (by weight). Tortillas prepared from the fortified flour blends, were evaluated for their nutritive value and sensory attributes. the alkalitreated chickpeas showed high per cent digestibility and reduced trypsin inhibitor activity. Fortified tortillas showed a significant increase in nutritive value with improved colour and texture when compared to the maize tortilla (control).
Studies on the control of the growth of Saccharomyces cerevisiae by using response surface methodology to achieve effective preservation at high water activities
Authors: KING V. AN‐ERL
Published: July 2010

Water activity (0.93‐0.97), pH (4‐6), and sorbic acid concentration (0‐50p.p.m.) were combined to study their effects on the growth of Saccharomyces cerevisiae. A three‐variable and three‐level design method, analysed by response surface methodology (RSM), was used. These factors were found to be significantly effective on the reciprocal of lag time, the growth rate, and the maximum population of the yeast grown in laboratory media. Fitted polynomial regression equations were plotted using a graphing software package. Inhibitory conditions of these three variables to the growth were determined based on these graphs. Results showed that S. cerevisiae could be inhibited at aw 0.94 and pH 4 with a sorbic acid concentration of 25 p.p.m. the predicted conditions of inhibition and the experimental values were consistent. This verified the adequacy of these predicted models. RSM was found to be appropriate for the study of food microbial growth only if the selection of the region of operating conditions was adequate.
The effect of 2‐furanmethanethiol upon the flavour of instant coffee
Authors: ELMORE J. STEPHEN , NURSTEN HARRY E.
Published: July 2010

2‐Furanmethanethiol (furfuryl mercaptan) is a constituent of the aroma of roasted coffee and the isolated compound has been reported to possess the aroma of fresh roasted coffee (Schutte, 1974; Tressl & Silwar, 1981). Because instant coffee is less flavoursome than fresh roasted coffee, a series of concentrations of 2‐furanmethanethiol were added to instant coffee, in order to determine if it would have a desirable effect upon the flavour of the coffee.

At no concentration was there a preference for the coffee containing added 2‐furanmethanethiol. At concentrations of added thiol above 100 parts per 109 (100p.p.b.), in both black and whitened coffee, there was a significant preference noted for the reference sample, which contained no added thiol. the three most used descriptors for the aroma of 2‐furanmethanethiol were burnt, then sulphurous, then coffee‐like.
Protein‐polysaccharide interactions: a new approach in food formulations
Authors: SAMANT S.K. , SINGHAL R.S. , KULKARNI P.R. , REGE D.V.
Published: July 2010

Food is a complex and heterogeneous system containing many different chemical types and species. In a product consisting of proteins, lipids, carbohydrates and electrolytes, the interactions among various constituents need to be well balanced so that a stable system evolves. Such interactions have become the subject of interest to many food scientists and technologists. One can find some interesting reviews dealing with these interactions and their role in food product development (Waugh, 1954; Gurd & Wilcox, 1956; Bettelheim‐Jevons, 1958; Tolstoguzov et al., 1985).

Polysaccharides, irrespective of their concentration, play a key role in determining food texture. Thickening, gelling and general hydrocolloid action are the most important, well recognized and widely used properties of polysaccharides in food product development. the charged polysaccharides have a special ability to interact with other food components such as other polysaccharides, proteins, lipids, and modify properties of foods (Steinhardt & Beychok, 1964; Blanshard, 1982; Keeney, 1982). In the present context, emphasis is given to protein‐polysaccharide interactions, their nature and effects in modifying properties of foods.
Sous vide cook‐chill technology
Authors: CHURCH IVOR J. , PARSONS ANTHONY L.
Published: July 2010

Cook‐chilled products are increasingly produced in the catering and food processing industries. It is claimed that the application of vacuum packaging followed by processing in‐pack (sous vide technology) improves both shelf life and eating quality, but in doing so presents an increased public health risk. This paper reviews the literature relating to the scientific basis of these claims. It demonstrates that, although they have some theoretical foundation, in practice they are unsubstantiated by research.
Development of a non‐isothermal method for determination of diffusional parameters
Authors: MOREIRA LÍLIA A. , OLIVEIRA FERNANDA A.R. , SILVA TERESA R. , OLIVEIRA JORGE C.
Published: July 2010

A non‐isothermal method for determination of diffusional parameters was developed. the dependence of diffusivity on temperature was described by an Arrhenius type equation, with the pre‐exponential factor and the activation energy as parameters. These parameters were obtained by optimization of the fit between experimental and theoretical values, using the Simplex method of minimization. Equilibrium conditions were described with a constant unit partition coefficient. This model was applied to the diffusion of acetic acid into turnips. Results compared well with values obtained with the conventional method, using a set of experiments at isothermal conditions. the non‐isothermal method has significant advantages, namely the need for much less experimental data and better insight into the statistical significance of the results.
Thermal transition temperature of connective tissues from marinated spent hen drumsticks
Authors: KIJOWSKI JACEK
Published: July 2010

Differential scanning calorimetry (DSC) was used to evaluate the effects of marination on the thermal transition temperature of connective tissues from spent hen drumsticks. Samples were heated in the calorimeter from 20 to 90°C at 10°C min1. Collagen of untreated epimysium, tendon and skin exhibited denaturation temperatures of 69.9, 72.0 and 69.4°C, respectively. As a result of marinating the samples in 2% NaCl, 1.5% acetic or lactic acid solutions for 72 h, significant (P< 0.05) decreases in the denaturation temperature of collagen were observed. Significant reductions of thermal resistance and degradation of collagen were observed in samples marinated in acid solutions. the denaturation temperatures of collagen obtained for epimysium were between 39‐66°C and 38‐67°C for acetic acid and lactic acid treatments, respectively. the heat resistance of collagen was partially reversible after removal of salt or acid ions by dialysis with distilled water.
Citric acid lowers heat resistance of Clostridium sporogenes PA 3679 in HTST white asparagus purée
Authors: SANTOS M.H. SILLA , ZARZO J. TORRES , SANTAMARTA A. ARRANZ , TORAN M.J. PERIS
Published: July 2010

The heat resistance parameters (DT and z) of Clostridium sporogenes PA 3679 spores were determined from 121 to 145°C (HTST conditions) in Sørensen 0.067 M phosphate buffer (pH 7.0) and in asparagus puree at natural pH (5.8) and at increasing levels of acidification (pH 5.5, 5.0 and 4.5) using citric acid as acidulant. the thermal resistance of the spores was higher when suspended in phosphate buffer pH 7.0 than in asparagus puree at all pH levels. the DT values obtained in asparagus puree decreased as the acidification level of the heating medium was increased by the addition of citric acid. Hie most evident effect was observed at the lower temperatures assayed. There was a general increasing trend in the value of the z parameter as the pH level of the heating medium rose (zpH4.5= 12.9°C; ZpH7.0= 14.5°C). the differences found were significant between z values for pH 4.5 and those calculated for pH 5.8 and 7.0.
Comparison of microwave, conventional and combination heat treatments on wheat germ lipase activity
Authors: KERMASHA S. , BISAKOWSKI B. , RAMASWAMY H. , VOORT F. VAN DE
Published: July 2010

Commercial wheat germ lipase inactivation was analysed at various temperatures with reference to conventional and microwave heating. A temperature controlled water‐bath was used for conventional heating. A custom designed microwave temperature control system was used to maintain test samples at selected temperatures either by full exposure to microwaves (microwave heating) or partial exposure by immersion in water (in a beaker) maintained at the desired temperature using the microwave oven (mixed mode). Lipase inactivation was analysed using first‐order kinetics resulting in activation energies (Ea) of 20.9, 25.4 and 18.7 kcal mole‐1 for the conventional, microwave and mixed mode heating, respectively. the activation energies of conventional and mixed mode heating were somewhat more comparable, while the microwave mode resulted in a slightly higher activation energy. the higher enzyme inactivation rate constants observed under microwave heating conditions were attributed to possible non‐thermal effects associated with microwave energy
Prediction of flavour intensity of blackcurrant (Ribes nigrum L.) drinks from compositional data on fruit concentrates by partial least squares regression
Authors: PIGGOTT JOHN R. , PATERSON ALISTAIR , CLYNE JANICE
Published: July 2010

Concentration of fruit juice by reduced pressure distillation causes substantial loss of volatile components, and produces new less‐volatile flavour compounds which affect the flavour of drinks prepared from the resulting concentrate. Free‐choice profiling indicated that blackcurrant drinks could be classified into three groups, depending mainly on the extent of processing. the flavour intensity of a series of drinks prepared from blackcurrant concentrate was measured by sensory analysis using magnitude estimation, and 214 volatile components of the concentrates were quantified by capillary gas chromatography. Partial least squares regression was successful in modelling the perceived flavour intensity of the drinks from gas chromatographic data on concentrate composition.
Performance, composition and sensory quality of adult channel catfish (Ictalurus punctatus) fed a dried waste egg product
Authors: CONRAD KATHLEEN M. , MAST MORRIS G. , MACNEIL JOSEPH H. , CLOUSER CAROL S.
Published: July 2010

The growth and carcass quality of adult channel catfish (176 mm, 76 g average length and weight) fed diets (6000 fish/diet) containing 14% and 28% dried, inedible whole egg were compared to similar fish fed a commercial or a formulated diet containing fish meal as the primary protein source. After 4 months, the fish fed 28% dried egg diet were 5–8% longer and 17–31% heavier, and had consumed 0.06–1.11 1b feed per 1b weight gain less than fish fed the other diets. Fish fed the egg diets had 0.9–1.2% less dress‐out and 0.3–2% more visceral cavity fat than fish fed the non‐egg diets. Diets containing eggs did not affect the sensory quality or shear press values of the cooked fish fillets.
The recovery of added malondialdehyde from rancid chicken by the distillation method for thiobarbituric acid‐reactive substances
Authors: KARASTOGIANNIDOU CALLIOPE , RYLEY JANICE
Published: July 2010

Roasted chilled chicken muscle which had been chopped and stored at 5°C was spiked with 1,1,3,3‐tetra‐ethoxypropane and steam distilled at 20–25 ml of distillate per min. Malondialdehyde concentration in the distillate decreased exponentially with distillate volume, producing 88% recovery in 10 min, more than double than in a previously published method with a similar rate of sample throughput.
Freezing points of selected seafoods (invertebrates)
Authors: RAHMAN MOHAMMED SHAFIUR , DRISCOLL ROBERT H.
Published: July 2010

The equilibrium freezing points of fresh invertebrate seafoods measured by the freezing curve method varied from −0.5 to −2.07°C. the freezing point of seafood was modelled by empirical and semi‐empirical correlations, and by theoretical equations derived from the Clausius‐Clapeyron equation and Raoult's law. Useful prediction were only obtained within species.
Apparent diffusivities of reducing sugars in potato strips blanched in water
Authors: KAYMAK FIGEN , KINCAL N. SUZAN
Published: July 2010

The mechanism of reducing sugar losses was investigated in potatoes cut into 9.5 × 9.5 mm and 13 × 13 mm strips and blanched for 300–2400s at different temperatures between 70°C and 100°C. Experiments were carried out using large amounts of well‐agitated water. Assuming no chemical reaction and using appropriate solutions of the unsteady state diffusion equation for square parallelpiped geometry, the apparent diffusivities, Da, of reducing sugars in the potato matrix were determined at different temperatures. the incorporation of the dimensions of the strips in the solution of the diffusion equation was sufficient to explain the effect of size on losses. Values of Da were found to be in the range 1.2 × 10‐11 1.7 × 10‐11 m2s‐1 and could be correlated with temperature according to the Arrhenius law.
Comparison of five three‐parameter equations for the description of moisture sorption data of mustard seeds
Authors: MAZZA GIUSEPPE , JAYAS DIGVIR S. , OOMAH B. DAVE , MILLS JOHN T.
Published: July 2010

Equilibrium moisture contents (EMC) of seeds of yellow, brown, and oriental mustards were determined at five different temperatures (2, 10, 25, 40, and 55°C) by equilibrating about 10‐g samples at relative humidities in the range of 11–96%, obtained using saturated salt solutions. the EMCs of all three types of mustard decreased with an increase in temperature at constant relative humidity. At most temperatures and at the relative humidities tested, oriental mustard seeds had the lowest, yellow mustard the highest, and brown mustard intermediate EMC values. Differences in the moisture adsorption characteristics of the three mustards were attributed to differences in mucilaginous material, oil and protein contents of the seed. the modified GAB equation together with four other commonly used three‐parameter equations (modified Henderson, Chung‐Pfost, Halsey, and Oswin equations) were evaluated for their ability to fit the experimental data for the three types of mustard. the modified GAB equation gave the best fit to the experimental data and the modified Oswin equation was the second best model for describing the EMC data of mustard seeds. the predicted safe storage moisture contents of oriental, brown and yellow mustard seeds at 25°C were 10.0, 10.6 and 10.7% (db), respectively.
Inhibition of tomato pectin methylesterase by partially purified kiwi pectin methylesterase inhibitor protein
Authors: MARQUIS HÉLÈNE , BUCHELI PETER
Published: July 2010

The inhibition of tomato pectin methylesterase (PME) by a recently discovered kiwi pectin methylesterase inhibitor (PMEI) is described. PME was consequently purified by CM Sephadex C‐50, Concanavalin A‐Sepharose 4 B and Mono S chromatography, and PMEI by Q‐Sepharose and Sephacryl S‐200 chromatography. Inhibition of tomato PME activity under optimal conditions (0.125 m NaCl, pH 7.5) by partially purified kiwi PMEI (MW of 27 kD, pI ≥ 3.67) was independent of the PMEI/PME ratio between 36 and 61% of the maximal uninhibited activity. the non‐competitive inhibition observed was optimal in the pH range of 5 to 7. PMEI was inactivated by heating to 120°C, and showed actinidin‐like activity towards N‐α‐benzyloxycarbonyl‐L‐lysine p‐nitrophenyl ester (CBZ‐lys‐ONp) and azocasein which was partially inhibited by the protease inhibitor leupeptin.