bluuebunny/crossref_metadata_2025 huggingface dataset:
Extrusion of cassava starch with either variations in ascorbic acid concentration or pH
Authors: Sriburi Pensiri , Hill Sandra E.
Published: March 2003

Summary Thermal mechanical extrusion is used to make cassava products that are later expanded by frying. During extrusion the native starch granules are broken down and starch polymers degraded. This continuum of change to the starch has been termed starch conversion. Inclusion of ascorbic acid promoted starch conversion as measured by a range of techniques including measurement of water solubility, water absorption, hot paste and alkaline viscosities. It was found that the Rapid Visco Analyser (RVA, Newport Scientific, NSW, Australia) was particularly sensitive in the monitoring of the changes owing to extrusion. Expansion of the extruded product was increased at the higher starch conversions caused by ascorbic acid addition. Changes in starch conversion were greater in the presence of ascorbic acid compared with general acid treatment at equivalent pHs. Although the general acidification did encourage more starch conversion there was no measured change in the expansion properties.
The influence of starch pore characteristics on pasting behaviour
Authors: Fortuna Teresa , Januszewska Renata , Juszczak Lesław , Kielski Andrzej , Pałasiński Mieczysław
Published: March 2003

Potato, wheat and corn starches were segregated into large and small granule fractions. The specific surface area, volume, and average diameter of pores, as well as the pasting characteristics of starch dispersions in water were determined. In all the starches investigated the small granule fractions were characterized by the largest specific surface area, pore volume and pore diameter in comparison to fractions of large granules and the initial starches. The small granule fraction of potato starch gave better pasting characteristics (apart from maximum viscosity) than fractions of large granules and the initial potato starch. On the other hand, the large granule fractions of corn and wheat gave the highest maximum viscosity.
The performance evaluation of a continuous vegetable cooker
Authors: Ramesh Mysore N.
Published: March 2003

Summary A continuous vegetable cooker was evaluated and shown to produce improved quality‐cooked vegetables under more hygienic conditions as compared to batch type conventional cooking. The operating parameters for 85 ± 3% degree of cooking as optimal were determined for green peas, carrot, kohlrabi, and radish. The final product was evaluated in comparison to conventional cooking in terms of the degree of cooking and product quality (retention of chlorophyll, vitamin C and carotenoids; microbial analysis). The thermal efficiency of the cooker and specific energy consumption were compared with published data for steam blanchers.
Disinfestation of Basmati rice by the use of γ‐radiation
Authors: Rao V. Sudha , Gholap Achyut S. , Adhikari Hemu , Nair P. Madhusudanan
Published: March 2003

The effect of low‐dose γ‐radiation on prepacked Basmati rice was studied in order to achieve disinfestation. Basmati rice procured from the local market was repacked in 1 kg pouches made from high‐density polyethylene (HDP) and biaxially oriented polypropylene : low‐density polyethylene (BOPP/LDP) laminate and irradiated at doses from 0.25 to 1.0 kGy. Within 1 month of storage at room temperature, non‐irradiated (control) Basmati rice developed heavy infestation. No infestation was observed in any of the irradiated samples even at 0.25 kGy and the rice could be stored for 6 months in a clean state. Irradiation (at 0.25 kGy) did not alter the moisture content of the rice. Likewise, no significant change was noted in the functional properties of irradiated rice, such as the swelling index, water absorption and in total volatile components responsible for the flavour of Basmati rice. During organoleptic evaluation, no significant difference was found between the acceptability of irradiated (0.25 kGy) and control rice. These results are significant in view of the high export potential of Basmati rice and the transit losses which are at present owing to infestation.
Lysine and tryptophan fortification of nixtamalized corn flour
Authors: Waliszewski Krzysztof N. , Estrada Yokiushirdhilgilmara , Pardio Violeta
Published: March 2003

Sensory evaluation was used to determine the effect of lysine and tryptophan fortification on certain properties of corn tortillas. Lysine and tryptophan were added to nixtamalized corn flour to give concentrations which were either 83, 100 or 150% of suggested FAO concentrations. The analysis of sensory panelists results as well as colour parameter changes of enriched tortilla have shown that nixtamalized corn flour would be capable of supplying up to 83% of lysine and tryptophan needed in the diet of an average consumer. It would be logical to offer enriched tortillas mainly to the low income groups of Latin Americans, who normally consume tortillas as a main source of protein in their diet.
The effect of the method of drying on the colour of dehydrated products
Authors: Krokida Magdalini K. , Maroulis Zacharias B. , Saravacos George D.
Published: March 2003

Summary We tested the hypothesis that an optimum method of drying fruit could be designed. The effect of the method used for drying on colour of apple, banana, potato and carrot was investigated for five different methods of drying: conventional, vacuum, microwave, freeze and osmotic drying. Colour characteristics were studied by measuring lightness (L), redness (a) and yellowness (b) using a Hunter Lab chromatometer. The method used to dry the material was found to significantly affect the three colour parameters. The changes in redness (a) and yellowness (b) were found to follow a first order kinetic model. Air‐, vacuum‐ and microwave‐dried materials caused extensive browning in the fruits and vegetables, this was manifested by a significant drop of the L parameter and an increase of the a and b parameters. Osmotically pretreated samples did not brown as much as the untreated samples and the value for lightness (L) decreased only slightly while a and b increased slightly. Freeze drying seems to prevent colour changes, resulting in products with improved colour characteristics.
Optimization of a spray drying process for flaxseed gum
Authors: Oomah B. Dave , Mazza G.
Published: March 2003

Spray drying of flaxseed gum was optimized using response surface methodology (RSM). Water seed ratio (7–20), feed temperature (25–100 °C) and outlet temperature (60–110 °C) were the factors investigated with respect to yield, rheological characteristics (apparent viscosity, dynamic viscosity, storage G′ and loss G″ moduli), colour and cyanogenic glycoside contents of the spray‐dried flaxseed gum. Optimization of the spray drying process was performed to achieve maximum yield and functionality (rheological properties) of flaxseed gum. Water : seed ratio and outlet temperature were the two major factors affecting the response variables of the gum. The highest yield of spray dried flaxseed gum was obtained at a water : seed ratio of approximately 18 L kg−1. Optimization for high yield led to the production of gums with low viscosities. Maximum stationary points for gum yield and minimum stationary point for rheological characteristics were observed at relatively high water : seed ratio (˜18), combined with moderate inlet feed temperature (61.7 °C) and high outlet temperature (92 °C).
Optimization of ingredients and process conditions for the preparation of puri using response surface methodology
Authors: Vatsala C. N. , Saxena C. Dharmesh , Rao P. Haridas
Published: March 2003

Models capable of predicting the product quality of puri have been developed using response surface methodology (RSM) and used to determine the optimum processing conditions. The overall sensory score, which is an indicator of colour, appearance, handfeel, texture, mouthfeel, taste and aroma; the shear value, an objective parameter for texture; and the oil uptake, were used to assess the product quality in the preparation of puri. The optimum conditions which were attained for maximum sensory score (6–7), minimum shear value (3–3.5 N), and minimum oil uptake (18–18.8%) were: flour extraction, 88.5%; water, 65.1 ml 100 g−1 flour (the corresponding farinograph consistency 450 BU at lever position 1:3); resting period, 28.8 min; frying temperature, 200 °C; and frying time, 37.5 s.
Performance assessment under field conditions of a rapid immunological test for transgenic soybeans
Authors: Fagan John , Schoel Bernd , Haegert Anne , Moore John , Beeby John
Published: March 2003

Current market conditions and food regulations make it necessary for international and domestic participants in the agrifood industry to structure supply chains that control the content of genetically modified (GM) material in their products. Tests to detect and/or quantify GM components represent an important tool in maintaining such supply systems. This study assesses the field performance of kits that employ lateral flow immuno‐technology to detect soybeans GM to be resistant to the herbicide glyphosate. Operators at 23 grain‐handling facilities were paid to conduct analyses on a series of blinded samples containing defined proportions of conventional and transgenic soybeans. The observed rate of false positives was 6.7% in an experiment in which the highest level of GM material was 1% and 22.3% in a second experiment in which the highest level of GM material was 10%. This difference may be attributed to increased risk of cross‐contamination with the higher level of transgenic material used in the second study. Samples containing 0.01% GM material were reported as genetically modified 6.70% of the time, while samples containing 0.1, 0.5 and 1% GM material were classified as genetically modified 29.5, 67.7 and 68.2% of the time, respectively. Thus, the frequencies of false negatives were 93.3, 70.5, 33.3 and 31.8% for samples containing 0.01, 0.1, 0.5 and 1.0% GM material. Samples containing 10% GM material were correctly reported as genetically modified in all cases. These results lead to the conclusion that the kit under study is useful in screening for lots of soybeans that contain high levels of GM material, but that, as a field tool, it is not effective in monitoring for GM material at the level of 1.0% or lower. Statistical and immunochemical analyses were carried out in order to assess the relative contributions of various factors to the error observed in these studies. These analyses indicated that limitations in operator performance, not defects in test kit materials, were the primary contributors, while sample size may play a secondary role. As both operator performance and sample size are independent of the specific characteristics of the test kit used in this study, it appears justifiable to generalize conclusions obtained here to other similar test systems.
Dynamic mechanical thermal analysis of aqueous sugar solutions containing fructose, glucose, sucrose, maltose and lactose
Authors: Cruz Isabel B. , Oliveira Jorge C. , MacInnes William M.
Published: March 2003

The glass transition of glucose, fructose, lactose, maltose and sucrose solutions at maximum cryo‐concentration was studied by Dynamic Mechanical Thermal Analysis (DMTA), using the disc bending technique. The glass transition temperatures were determined from the peaks in the loss modulus E′′, which corresponds theoretically to the resonance point (Maxwell model) for several input frequencies. The frequency dependence was well described by both an Arrhenius‐type model and by the WLF (Williams, Landel and Ferry) equation, yielding glass transition temperatures for an average molecular vibration time of 100 s, which were similar to published midpoint temperatures determined by DSC scans. Some sugar mixtures were studied, yielding results that were well described by the Gordon–Taylor equation, using literature data. The frequency dependence of the viscoelastic ratio was also well approximated by an Arrhenius‐type equation, with activation energies similar to those of the glass transition temperature and corresponded well to published values of the endset of glass transition.
Texture of rehydrated dried bell peppers modified by low‐temperature blanching and calcium addition
Authors: Domínguez Rocio , Quintero‐Ramos Armando , Bourne Malcolm , Barnard John , Talamás‐Abbud Ricardo , Jiménez‐Castro Jorge , Anzaldúa‐Morales Antonio
Published: March 2003

Diced green bell pepper was blanched twice, once at 51–79 °C for 19–61 min, and once at 95 °C for 3 min, and dried. The firmness of rehydrated samples was measured by puncture, and optimum conditions assessed by response surface methodology. The optimized model showed that, blanching at 65 °C for 49 min gave a 64% increase in puncture force over the control. The optimum temperature was used to evaluate the effect of adding CaCl2. The dices were blanched twice, once at 65 °C for 3 min in either 0 or 4% CaCl2, secondly in either 0 or 2% CaCl2 solution at 95 °C for 3 min. In the second case the dices had been held at room temperature for 0–30 min before treatment. Adding CaCl2 increased puncture force significantly (P ≤ 0.05). The best results, those which gave greatest firmness, were obtained by blanching at 65 °C for 3 min in 4% CaCl2, holding for 16 min after blanching, followed by a secondary blanching at 95 °C in 2% CaCl2.
Anti‐oxidant activity of added tea catechins on lipid oxidation of raw minced red meat, poultry and fish muscle
Authors: Tang Shuze , Sheehan David , Buckley D. Joe , Morrissey Patrick A. , Kerry Joe P.
Published: March 2003

The comparative anti‐oxidative effects of added tea catechins (TC) and α‐tocopherol to raw minced red meat (beef and pork), poultry (chicken, duck and ostrich) and fish (whiting and mackerel) muscle on susceptibility to lipid oxidation were investigated during 10 days of refrigerated (4 °C) display. Fresh meats, poultry and fish, purchased from a local market, were trimmed to remove bones, skin and surface fat and minced through a 4 mm plate. The minced muscle of each species was treated with either the addition of 300 mg TC kg–1 minced muscle (TC300) or 300 mg α‐tocopherol kg–1 minced muscle (VE300). Minced muscle without any additives served as control (C). Oxidative stability (TBARS) was measured at 3‐day intervals. Total lipids, fatty acid composition, total iron and haem iron from minced muscle for each species were also analysed. The susceptibility of untreated minced muscle to lipid oxidation was in the decreasing order: mackerel > beef > duck > ostrich > pork ≥ chicken > whiting. This may be because of the different content of total fat, iron and fatty acid composition between species. The TC300 significantly (P < 0.05) reduced lipid oxidation compared with controls for all seven species as shown by lower TBARS values. The anti‐oxidant potential of TC was two to fourfold greater than that of α‐tocopherol at the same concentration and this potential was species dependent. The VE300 showed limited capacity in inhibiting lipid oxidation for pork, chicken, duck and whiting. The results obtained show that TCs are powerful natural antioxidants when used in minced muscle food.
Bacterial dormancy in Campylobacter: abstract theory or cause for concern?
Authors: Moore John E.
Published: March 2003

For the past 100 years, since the birth of modern microbiology, this discipline has predominantly relied on the ability to culture micro‐organisms in vitro on artificial synthetic culture media under controlled conditions in the laboratory. However, sometimes it is not possible to detect foodborne pathogens using such conventional techniques. Employment of these techniques can also lead to a delay in detection of pathogens. The ‘viable but non‐culturable’ (VNC) cellular form has been demonstrated in Campylobacter jejuni, representing a resting or dormant stage, which is induced through cell stress including starvation. This form is extremely difficult to detect and generally requires complex and sophisticated technology which is usually not available in most routine food microbiology laboratories. This review aims at examining the role of this cell form in Campylobacter, including their historical evolution, formation, physiology, detection and to discuss the challenges that this form presents to food safety.
Effect of salt concentrations and temperature on the quality and shelf‐life of brined anchovies
Authors: Karaçam H. , Kutlu S. , Köse S.
Published: March 2003

In this study, the shelf‐life and quality of anchovies brined at different concentrations and stored both at refrigerator and ambient temperature conditions were investigated. Sensory, microbiological and chemical analyses of samples were made during storage trials for up to 150 days in order to investigate their quality. The samples stored at ambient temperature showed poor quality at the end of the storage trial. The best quality was observed with the samples that were brined at 22 and 26% salt concentrations, and stored at 4 ± 1 °C.
Extension of shelf‐life of whole‐wheat flour by gamma radiation
Authors: Marathe S. A. , Machaiah J. P. , Rao B. Y. K. , Pednekar M. D. , Sudha Rao V.
Published: March 2003

The effect of low‐dose gamma irradiation (0.25–1.00 kGy) on pre‐packed whole‐wheat flour (atta) was assessed in terms of physico‐chemical properties, nutritional quality, chapati‐making quality and sensory attributes. Semi‐pilot scale storage studies on irradiated pre‐packed whole‐wheat flour revealed that there was no adverse effect of irradiation and storage up to 6 months of whole‐wheat flour treated at doses up to 1.00 kGy on total proteins, fat, carbohydrates, vitamin B1 and B2 content, colour index, sedimentation value, dough properties, total bacterial and mould count. Storage of wheat flour resulted in slight increase in moisture, free fatty acids, damaged starch, reducing sugars and slight decrease in gelatinization viscosity.

However, irradiation as such had no effect on any of these parameters. Irradiation at 0.25 kGy was sufficient to extend the shelf‐life of atta up to 6 months without any significant change in the nutritional, functional attributes. Chapaties made from irradiated atta (0.25 kGy) were preferred even after 6 months storage, compared with the control.
Sensory, chemical and microbiological assessment of farm‐raised European sea bass (Dicentrarchus labrax) stored in melting ice
Authors: Kyrana Vasiliki R. , Lougovois Vladimiros P.
Published: March 2003

Farm raised European sea bass (Dicentrarchus labrax) were stored in melting ice for a period up to 22 days from the time of harvest, and sensory, chemical, and microbiological assessments were made at intervals. The storage life of the ungutted fish, determined by sensory evaluation of the cooked flesh, was 19 days. Of the chemical tests, only k1 value provided a useful means of monitoring early storage change. Trimethylamine, total volatile bases and pH showed practically no change during the first half of the edible storage life of the fish. Changes in free fatty acid (FFA) content and thiobarbituric acid (TBA) value could not be used to determine loss of acceptability or end of storage life. Sulphide producing bacteria constituted a very low proportion of the total aerobic flora, suggesting that the common sulphide producer Shewanella putrefaciens was not a major spoiler of sea bass in this trial.
Volatile composition of `grappa low wines' using different methods and conditions of storage on an industrial scale
Authors: Da Porto Carla
Published: March 2003

This is a study on the volatile composition of grappa low‐wines. Grappa low wines are the first distillation products, with about 15–20% v/v ethanol, when grappa is produced using continuous distillation. Different methods and conditions of marc and wine lees storage on an industrial scale have been considered. New technology for the storage of large amounts of grape marc, called the `Grappa system', was evaluated. By comparison with a traditional ensilage method, the low‐wines obtained from the Grappa system resulted in higher concentrations of ethanol, lower levels of methanol, slightly different concentrations of fusel alcohols and higher concentrations of ethyl esters and terpenes. The use of phosphoric acid and sodium methabisulphate to achieve a partial control of marc fermentation had no effects using the Grappa system method. This could be the result of the mixing technique used which was spraying alone and was only slightly effective for the homogenous treatment of the mass. On the contrary, the lower content of methanol, 2‐butanol and n‐propanol confirmed the effectiveness of phosphoric acid addition to the wine lees.
Sous videcooked beef muscles: effects of low temperature–long time (LT–LT) treatments on their quality characteristics and storage stability
Authors: Vaudagna Sergio R. , Sánchez Guillermo , Neira Maria S. , Insani Ester M. , Picallo Alyandra B. , Gallinger Maria M. , Lasta Jorge A.
Published: March 2003

Beef muscles weresous videcooked by applying different low temperature‐long time treatments and changes in their physical properties were measured. The effects of selected treatments on pasteurization values and chilled storage stability were investigated. The results obtained indicated that cooking weight loss increased and shear force values decreased as the treatment temperature was raised from 50 to 65 °C, while processing times (90–360 min) did not have a significant effect on these variables. The colour parameterawas strongly affected by the different treatments. The pasteurization values obtained were enough to inactivate vegetative cells but were insufficient to achieve a significant reduction ofClostridium botulinumspores. The microbial quality of the product remained acceptable during the storage period. Over the storage time, thiobarbituric acid reactive substance (TBARS) numbers were significantly affected by the thermal treatment applied. Maximum TBARS values obtained were lower than those reported for meat processed without vacuum. Cooked beef flavours for all treatments decreased uniformly after 21 days of storage.
Comparative study of cream in infusions of black tea and green tea [Camellia sinensis (L.) O. Kuntze]
Authors: Liang Yuerong , Lu Jianliang , Zhang Lingyun
Published: March 2003

Summary Particle size, concentration and chemical composition of green‐tea cream and black‐tea cream were studied. Tea‐cream particle size tended to decrease during tea fermentation and average size of tea‐cream particles was bigger for green than for black tea. The amount of tea‐cream formed in tea infusions depended on their chemical composition. Tea catechins and their oxidation products formed tea‐cream when they interact with some non‐catechin compounds in tea liquor. Model fermentation tests revealed that little tea‐cream was found in solution of crude tea catechins and the tea‐cream formed after fermentation did not significantly increased in the crude tea catechins solution. Tea extract prepared at 50 °C formed less tea‐cream than those prepared at 90 °C before and after fermentation. Caffeine, gallocatechin (GC) and epigallocatechin gallate (EGCG) were the predominant compounds in green‐tea cream but thearubigins (TRs), caffeine and theaflavins (TFs) in black‐tea cream. Gallated catechins and gallated TFs had stronger creaming ability than un‐gallated catechins and TF. How to control tea liquor from creaming down is discussed.
Characterization of globulin from Phaseolus angularis (red bean)
Authors: Meng Guangtao , Ma Ching‐Yung
Published: March 2003

Phaseolus angularis
(red bean) seeds contain about 25% protein (dry basis), almost half of which is globulin. Similar to globulins from other
Phaseolus
species
, 7S vicilin is the major fraction of red bean globulin (RBG), with 11S legumin as a minor component. The amino acid profile of RBG met or exceeded the FAO/WHO standard. Circular dichroism measurements indicate that RBG is a protein rich in α‐helical and β‐turn structures. RBG exhibited higher protein solubility than Supro 610, a commercial soy protein isolate, especially at acidic pHs, with minimal solubility at around pH 5.0. Compared to Supro 610, RBG had lower water hydration capacity and comparable fat binding capacity, which might be because of its lower surface hydrophobicity. RBG had higher emulsifying activity index and emulsion stability than Supro 610, but with poorer foaming properties.
Comparison of wild and cultured gilthead sea bream (Sparus aurata); composition, appearance and seasonal variations
Authors: Grigorakis Kriton , Alexis Maria N. , Taylor K. D. Anthony , Hole Michael
Published: March 2003

Major quality parameters, such as muscle composition, fat deposition, muscle fatty acid composition and external appearance were studied in wild and cultured gilthead sea bream. Muscle fat content and total depot fat (peritoneal and perivisceral fat) indicated a seasonal variation with minimum values observed in late spring and maximum in late summer. Gonadosomatic indices of cultured fish were lower than those found in wild specimens. Lipid content of cultured sea bream was much higher than that of wild fish. Differences were also observed in fatty acid profiles. Cultured fish were characterized by higher levels of monoenes, n‐9 and 18:2n‐6 fatty acids and wild fish by higher levels of saturates, 20:4n‐6, n‐3 fatty acids and n‐3/n‐6 ratios. Differences were also noted in the external appearance of fish.
The microbiology of phytic acid metabolism by gut bacteria and relevance for bowel cancer
Authors: Steer Toni E. , Gibson Glenn R.
Published: March 2003

Colon cancer is a major cause of morbidity and mortality. Compounds present in plant foods have anti‐carcinogenic properties that may be metabolised by colonic bacteria thus decreasing or preventing any such beneficial effects. Phytic acid is found mostly in legumes and appears to possess anti‐carcinogenic properties. This may be due to a number of factors including the recognised ‘binding’ properties of phytate. For this to occur successfully it is important that the integrity of phytic acid is preserved in the colon, which is a profuse microbial ecosystem. However, there are few data on the microbial species involved in its metabolism. Studies that define the populations involved may lead towards the use of dietary intervention procedures that can reduce the activities of the microflora involved in phytate degradation, thereby preserving its purported anti‐tumour properties.
Composition and functional properties of rice
Authors: Zhou Zhongkai , Robards Kevin , Helliwell Stuart , Blanchard Chris
Published: March 2003

Summary Starch, protein and lipids are the main rice grain components that affect cooking and eating quality. An analysis of the literature indicates that rice of good eating quality shows the following characteristics: low amylose and low protein contents and large breakdown as measured by an amylograph. However, there are significant cultural differences in quality preferences and the most important acceptance factors for Asian consumers living in the United States are cooked rice appearance and aroma. This review examines the major constituents of rice (starch, lipid and protein) and their impact on eating quality as reflected by the functional properties of rice.
Aspects of 2‐acetyl‐1,3‐cyclopentanedione as a chromium(iii) chelating agent: nutritional implications
Authors: Blanco Carlos , Rojas Antonio , Gomez Manuel , Ronda Felicidad , Caballero Pedro
Published: March 2003

The chemistry of 2‐acetyl‐1,3‐cycloalkanediones has acquired increased applied importance because of the great number of applications in the agroalimentary industry. The keto‐enol ratios and equilibrium constants for proton reactions of 2‐acetyl‐1,3‐cyclopentanedione have been determined in solution using nuclear magnetic resonance and spectrophotometric methods. Chromium(iii) is an essential nutrient and it seems that high chromium supplementation improves glucose tolerance. Chromium chelates have been shown to have a significant beneficial effect on metal status by increasing metal bioavailability in human diets.

The composition and log β‐value of the complex formed in aqueous solution by chromium(iii) with the ligand mentioned above have been determined. A detailed reaction scheme is proposed for the 1 : 1 chelation process. The kinetic data are consistent with a mechanism in which the mono‐enol tautomer of the ligand reacts with both metallic species, the fully hydrated metal ion and the Cr(OH)2+. The results are discussed in the light of previous work.
Enzymatic synthesis of ethyl hexanoate by transesterification
Authors: Chowdary G. V. , Prapulla S. G.
Published: March 2003

Summary Enzymatic synthesis of ethyl hexanoate by means of an acyl transfer reaction has been studied by using an immobilized Rhizomucor miehei lipase (RML). The effect of reaction parameters on ester synthesis has been investigated. Rhizomucor miehei lipase showed more specificity than other lipases when ethyl hexanoate was synthesized in n‐hexane. Maximum ester synthesis was obtained by using a 0.5 m substrate concentration (equimolar ratio). Temperatures in the range of 45–55 °C were found to be optimum and at higher temperatures (>60 °C) deactivation of enzyme was observed. Higher molar concentrations of hexanoic acid inhibited RML, but no inhibitory effect of ethyl caprate, even at higher molar concentrations, was observed. Apparent kinetic parameters have been determined. The values are as follows: KM (ester), 0.0135 m; KM (acid), 0.08466; Ki (ester), 3.07 m; Ki (acid), 0.550 m; Vmax, 1.861 µmol min−1 mg−1 enzyme.
Kinetic modelling of textural changes in ready‐to‐eat breakfast cereals during soaking in semi‐skimmed milk
Authors: Sacchetti Giampiero , Pittia Paola , Biserni Manuela , Pinnavaia Gian G. , Rosa Marco D.
Published: March 2003

Summary Ready‐to‐eat breakfast cereals immersed in milk undergo undesirable changes in texture because of sudden moisture uptake. The textural changes are ascribable to a plasticizing effect of water, which modifies the mechanical strength of products by softening the starch/protein matrix. In this work, some textural parameters of different cereal flakes were derived from the force–displacement curves monitored during 300 s of immersion in milk. Hardness loss, deformability increment and changes in the force–displacement curve profile were calculated and plotted against soaking time. The application of a sugar coating process to a model cereal flake increased the initial product hardness and improved the preservation of the textural parameters during immersion. The Peleg model closely fitted the experimental data, with regression coefficients from 0.967 to 0.999.
Evaluation of a polymer coating containing triclosan as the antimicrobial layer for packaging materials
Authors: Chung Donghwan , Papadakis Spyridon E. , Yam Kit L.
Published: March 2003

Summary A coating made of a styrene‐acrylate copolymer and containing triclosan (87 ± 9 mg triclosan cm−3 coating) was evaluated as an antimicrobial layer for packaging materials. In both agar diffusion tests and liquid culture tests, inhibition of growth of Enterococcus faecalis by the triclosan‐coating was observed. Triclosan in the coating was not released into the water. Using a solution of 10% aqueous ethanol to simulate aqueous/acidic foods, a very small portion of the triclosan was quickly released with an estimated apparent partition coefficient of 1.7 × 10−5. When using n‐heptane, to simulate fatty foods, most of the triclosan was extracted with an estimated apparent partition coefficient of 5.5 × 10−2.
The use of nisin as a preservative in fish sausage stored at ambient (28 ± 2 °C) and refrigerated (6 ± 2 °C) temperatures
Authors: Raju C. V. , Shamasundar B. A. , Udupa K. S.
Published: March 2003

Summary The efficacy of nisin at three different concentrations, 12.5, 25 and 50 ppm, on the keeping quality of fish sausage in synthetic casing at ambient (28 ± 2 °C) and refrigerated (6 ± 2 °C) temperatures was assessed. Gel strength, expressible water content, total volatile base nitrogen, total plate count and aerobic spore counts were affected by the storage temperatures and nisin concentrations used. Fish sausage treated with 50 ppm of nisin was acceptable after storage at ambient temperature for 20–22 days compared with the control, which were acceptable only for 2 days. The keeping quality of the sausages, at refrigerated temperature, varied from 30 days in the control to 150 days in 50‐ppm nisin‐treated samples. The residual nisin decreased slowly in samples stored at refrigerated temperature, whereas, in fish sausages stored at ambient temperature, the decrease was rapid. Nisin at 50‐ppm level showed a significant effect (P ≤ 0.05) on the gel strength and overall acceptability scores both at ambient and refrigerated temperature.
Preservation of fatty duck liver by high pressure treatment
Authors: Cruz Christian , El Moueffak Abdelhamid , Antoine Monique , Montury Michel , Demazeau Gérard , Largeteau Alain , Roy Bernadette , Zuber François
Published: March 2003

Fatty liver samples from duck were treated with high pressures and packaged in multilayer films. Microbiological analysis, permeability of the films to oxygen and fat loss, caused by melting, were assessed after pressure or thermal treatment.

Microbiological analysis showed a noteworthy reduction in the total aerobic mesophilic flora and eradication of the coliform flora, whichever film or treatment was used. Nevertheless, a significant bacterial flora was observed during storage at 4 °C from 42 days with a polyethylene/polyamide/polyethylene film and a sample which had been treated with pressure. But, treatment at 550 MPa for 55 °C and 20 min, in combination with two low oxygen permeability films (ethylene and vinyl alcohol copolymer) gave a product with long storage life (90 days) at 4 °C and a significant reduction in the melting of lipids.
Investigation of nitrous oxide pollution arising from inhalational sedation for the extraction of teeth in child patients
Authors: Girdler  , Sterling
Published: March 2003

Objectives. (i) to test whether the exposure of dental staff to nitrous oxide during inhalational sedation with nitrous oxide/oxygen for extractions in children complies with specified occupational exposure standards, and (ii) to assess the atmospheric nitrous oxide concentration at one site close to the breathing zone of the operator/sedationist and to determine which patient‐ and sedation‐related factors affect the level of nitrous oxide pollution.

Design. Prospective study.

Setting. Dental hospital sedation department, Newcastle Dental Hospital, UK.

Sample and methods. 20 inhalational sedation clinics each of 2 hours duration were evaluated, during which a total of 60 children aged 4–15 years had extractions carried out. Nitrous oxide was administered via a nose mask from a Quantiflex MDM inhalational sedation machine and active scavenging was used throughout. Exposure of dental staff was measured using personal dosimetry. Atmospheric nitrous oxide pollution at one fixed point, close to the breathing zone of the operator/sedationist, was assessed using an infra‐red gas analyser.Results. Mean exposure of the operator/sedationist to nitrous oxide during a single treatment clinic was 211 ppm, for the close support nurse 77 ppm and for the second nurse 67 ppm. Expressed as an 8 hour time‐weighted average, the mean exposures were 39 ppm for the operator/sedationist, 17 ppm for the close support nurse and 15 ppm for the second nurse. The atmospheric nitrous oxide concentration varied during the clinics, with a maximum concentration of 538 ppm and a minimum that exceeded 100 ppm. There was a 71 minute delay following discharge of the last patient before atmospheric levels fell to zero. During sessions the degree of atmospheric pollution was inversely related to patient age (rc = −0·61, P < 0·05). There was a positive correlation between atmospheric pollution at the single point and the maximum percentage of nitrous oxide administered to each patient (rc = 0·57, P < 0·05).Conclusions. In this study, staff exposure to nitrous oxide complied with the national occupational exposure standard but there was still considerable atmospheric nitrous oxide pollution during inhalational sedation for paediatric exodontia.
The effect of two alternative methods of canine exposure upon subsequent duration of orthodontic treatment
Authors: Iramaneerat  , Cunningham  , Horrocks
Published: March 2003

Objectives. The aim of this study was to compare the effectiveness, in terms of orthodontic treatment duration, of two methods of canine exposure.

Design. This was a retrospective study using patients’ records and lateral cephalometric radiographs.

Sample and methods. 50 patients were selected, 25 in each group. In all subjects the impaction was categorized as being ‘intermediate’. The methods of canine exposure were: (i) simple surgical exposure; (ii) surgical exposure and placement of an orthodontic attachment, followed by flap replacement.

Results. The treatment duration until the canine was in the line of the arch was 17·7 months in the simple exposure group and 19·3 months in the bonded attachment group. The mean treatment duration (from exposure to debond) was 28·8 months for both groups.

Conclusions. In terms of treatment duration, no significant difference could be demon‐strated between the two methods of surgical exposure to palatally impacted canines.
Dental maturation of 18th and 19th century British children using Demirjian’s method
Authors: Liversidge H.M.
Published: March 2003

Aim. To compare dental age with chronological age in a group of children born approximately 200 years ago and a group of modern children.

Methods. Dental maturation of 15 skeletal remains (range 3·0–15·1 years) of London children of known age‐at‐death was compared to an age and sex matched control group of contemporary children (n = 30). The method of Demirjian, Goldstein and Tanner (1973, 1976, 1978) was used to assess maturity.

Results. The difference between dental age (DA) and chronological age (CA) for both groups was not significant, suggesting similar maturation over 200 years, however, many of the younger children from Spitalfields were dentally delayed. Several of the younger individuals from both groups had a dental age less than the lowest limit of this scale (2·5 years), highlighting one pitfall of this method.

Conclusion. These results suggest that this method is not entirely suitable for younger children.
Witkop tooth and nail syndrome: report of two cases in a family
Authors: Hodges S.J. , Harley K.E.
Published: March 2003

Tooth and nail syndrome, an autosomal dominant condition, is characterized by hypodontia and nail dysplasia. Mandibular incisors, second molars and maxillary canines are the most frequently missing teeth. Tooth shape may vary and conical and narrow crowns are common. Nail dysplasia affects fingernails and toenails and is often more severe in childhood. Nails may be spoon‐shaped, ridged, slow growing and easily broken. The clinical and radiographic features of a father and son presenting with this rare condition are described.
Individualized mouth prop for dental professionals and carers
Authors: Geary J.L. , Kinirons M.J. , Boyd D. , Gregg T.A.
Published: March 2003

Maintaining a high standard of dental health in children with special needs, particularly those who are unable to control mandibular activity, can prove difficult and time consuming for parents, carers and dental professionals. This article describes the construction of an individually made and relatively unobtrusive finger guard mouth prop, designed to facilitate intraoral examination and oral hygiene care for these children. An initial evaluation by a number of users found these mouth props were simple to fit, stable and provided adequate finger protection. All users planned to continue using their mouth prop after the trial period. It is concluded that similar finger mounted mouth props may help facilitate dental care and oral hygiene for children requiring special care.
A preliminary investigation of dental disease in children with HIV infection
Authors: Gelbier M. , Lucas V.S. , Zervou N.E. , Robertssurname G.J. , Novelli V.
Published: March 2003

Objective. To establish the levels of dental caries and gingivitis in a group of HIV‐positive children.

Study group. The study group comprised 35 children with the Human Immunodeficiency Virus attending The Great Ormond Street Hospital For Children.

Outcome measures. Outcome measures included the number of decayed, missing and filled teeth and surfaces in both the primary and permanent dentitions; plaque and gingivitis scores.

Results. The children included 18 boys and 17 girls. They were aged from 6 months to 18 years, with 17 aged 5 years or less and 15 aged 6 years or older. Twenty‐four of the 35 children had some caries experience. The mean dmft was 4·4 and for those with permanent teeth the mean DMFT was 0·7. Mean plaque and gingivitis scores were 16·7 and 5·1 for plaque and gingivitis adjacent to primary teeth and 8·0 and 5·7 for that related to permanent teeth.

Conclusions. There is a significant treatment need for children with HIV.
Dental anxiety among young adolescent patients in Israel
Authors: Peretz Benjamin , Efrat Jacob
Published: March 2003

Aim. To evaluate adolescents’ dental anxiety using self‐reported questionnaires previously given to adults.

Sample and method. One hundred and four patients (42 boys, 62 girls) aged 12–18 years who attended their paediatric dentist completed a questionnaire in the waiting room. The survey consisted of three sections: sociodemographic information for the children, a dental anxiety scale (DAS), and a dental fear survey (DFS).

Results. The scores of the girls were higher than the boys in every DAS item as well as in the total score. Girls showed higher DFS scores than boys in most items. The most anxiety‐provoking stimuli were feeling and seeing the needle. In the most anxiety provoking stimuli, among the boys who reported higher DFS scores (categories 3, 4, 5), the DAS scores were higher than the scores of the girls. As the stimulus became less anxiety‐provoking, such as sitting in the dental chair, the DAS scores of the girls in these categories were higher than boys. Significantly more girls’ responses were in categories 3, 4 and 5 in the items dealing with the needle and the drill, while no significant difference was observed among the boys and girls regarding sitting in the dental chair.

Conclusions. It is concluded that individual personality traits may be the final factor to indicate those who will eventually develop higher dental anxiety, and those who will not. The difference could be also in the conditioning process and learned responses (male and female education) that these individuals have experienced in life.
Garre’s osteomyelitis of an unusual origin in a 8‐year‐old child. A case report
Authors: Oulis C. , Berdousis E. , Vadiakas G. , Goumenos G.
Published: March 2003

Garre’s osteomyelitis is a type of chronic osteomyelitis that primarily affects children and adolescents. Although the disease is well described in the dental literature and is usually associated with an odontogenic infection resulting from caries, a number of other causative factors have been occasionally reported, such as a dental extraction or a mild periodontitis. There have also been cases of unknown aetiology. This paper describes a case of Garre’s osteomyelitis in an 8‐year‐old child, in whom the condition arose following a local periodontal infection in an ectopically erupting first permanent molar that was in infraocclusion. The lesion remained unresolved for a period of over 6 months as a result of misdiagnosis, following a number of unsuccessful treatment attempts. Identification of the true cause and treatment through periodontal surgery resulted in lesion resolution and resolved the diagnostic problem. Dentists should be aware that the periodontium may be a potential source of infection for Garre’s osteomyelitis in children, particularly in the presence of ectopically erupting posterior teeth. In such cases, periodontal treatment should be sufficient to treat the disease and extraction of the tooth involved may not be necessary.
Primary molar pulp therapy – histological evaluation of failure
Authors: Waterhouse P.J. , Nunn J.H. , Whitworth J.M. , Soames J.V.
Published: March 2003

Objectives. Qualitative comparison of the clinical, radiographic and histological outcomes in a small sample of cariously exposed primary molars, extracted after unsucessful pulp treatment by two vital pulpotomy methods.

Subjects and methods. The primary molars were extracted, because of treatment failure, during a longitudinal clinical investigation of the relative efficacy of 20% Buckley’s Formocresol versus calcium hydroxide powder as pulp dressings in vital pulp therapy (in press). Fifty‐two child patients were sequentially enrolled in the longitudinal clinical investigation, 26 boys and 26 girls. Primary molar teeth requiring vital pulp therapy were randomly allocated to either the formocresol group (F) or the calcium hydroxide group (C). Coronal pulp amputation was prescribed only in teeth with vital, cariously‐exposed pulp tissue. All cases were reviewed using predefined clinical and radiological criteria. Seventy‐nine cariously‐exposed primary molars required vital pulp therapy. Forty‐four teeth were included in group F and 35 in group C. Five per cent (n = 2) of teeth in group F and 11 per cent of teeth (n = 4) in group C were terminated from the trial due to clinical and/or radiographic failure. Of the six teeth extracted, five were sufficiently intact to be retained for histological evaluation.

Results. Post‐extraction radiographs taken before specimen preparation showed reactionary dentine barrier (bridge) formation in teeth treated with calcium hydroxide. However, the narrowing of root canals, indicative of appositional reactionary dentine deposition, was seen in both groups (F and C). Histological examination confirmed these findings and revealed that pus cells were evident in all specimens examined. There was also histological evidence of resorption of reactionary dentine within the root canal and that forming the calcified barrier (dentine bridge).

Conclusion. The clinical and radiographic outcomes for the five teeth correlate well with the reported findings from decalcified histological section. Although numbers are small, the histological findings may indicate possible reasons for treatment failure. There are few reports of this sort in the literature of this under‐researched treatment modality.
Pyogenic granuloma subsequent to injury of a primary tooth. A case report
Authors: Aguilo L.
Published: March 2003

Summary. This paper shows a case of pyogenic granuloma occurring as a post‐traumatic oral lesion, in a 19‐month‐old patient. The palatally chamfered fracture of a maxillary primary incisor together with the continuous sucking of a dummy could have caused the special shape of the pyogenic granuloma over the remaining coronal fragment.