bluuebunny/crossref_metadata_2025 huggingface dataset:
Whey protein aggregates and their interaction with exo‐polysaccharides
Authors: de Kruif Kees G. , Tuinier Remco
Published: March 2003

Summary We made a systematic investigation of the interaction of an exo‐polysaccharide (EPS) with whey proteins. The EPS was produced by a lactic acid bacterium Lactococcus lactis subsp. cremoris strain NIZO B40. The interaction of the EPS with milk components is of relevance to the consistency of fermented milk products. EPS and whey protein isolates (WPI) can be mixed in all proportions. Even at an EPS concentration of 10 g.L−1 no instability is visible. In yoghurt milk the whey proteins are usually denatured. We prepared aggregated whey protein colloid particles (AWC particles) which had an average radius of 27 ± 3 nm, as derived from the radius of gyration. The interaction of AWC particles and EPS was studied at a neutral pH and an ionic strength of 0.1 m. At low EPS concentrations the mixture was stable. At higher concentrations the mixtures showed phase separation owing to depletion interactions. In the one‐phase region the strength of the segregative interaction can be determined from turbidity, light scattering and neutron scattering measurements. Then, by applying statistical mechanical methods, the position of the phase boundary could be predicted. The viscosity of the mixtures was increased owing to the segregative interactions in the EPS/AWC mixtures. Within the two‐phase region the mixtures showed so‐called spinodal decomposition, during which different microstructures were formed. Understanding the formation of such structures is of interest for the development of new food structures.
The extension of the shelf‐life of ‘pesto’ sauce by a combination of modified atmosphere packaging and refrigeration
Authors: Fabiano Bruno , Perego Patriza , Pastorino Renato , Del Borghi Marco
Published: March 2003

Summary This study was intended to extend, by optimizing modified atmosphere packaging (MAP), the shelf‐life of the Italian vegetable sauce used for spaghetti and known as ‘pesto’. A mathematical model was developed in order to predict gas composition inside the polymeric package (CO2 concentration). Predictions of equilibration time and equilibrium gas composition showed moderately good agreement with experimental data. A useful extension of pesto shelf‐life, up to 120 days, was achieved by adopting a target atmosphere containing, at steady‐state, 10% CO2 and 90% N2 at 5 °C. Microbial growth was inhibited by the CO2 levels, but was not accompanied by significant changes in odour and colour.
Chemical and sensory changes in white wines fermented in the presence of oak chips
Authors: Pérez‐Coello M. S. , González‐Viñas M. A. , García‐Romero E. , Cabezudo M. D. , Sanz J.
Published: March 2003

Summary Three samples of French oak and one sample of American oak were analyzed by different gas chromatographic‐mass spectrometric (GC/MS) methods. Two methods of quantifying the main volatile compounds in oak wood were compared, namely, Direct Thermal Desorption coupled with GC/MS and analysis of mixtures of water‐ethanol and wines that had been in contact with oak chips by extraction using an organic solvent followed by GC/MS analysis of the extract. The ratio of the two oak lactones released into the wine by the oak chips was the same as the ratio observed in original, untreated wood. These substances are of particular sensory importance in wines aged in oak wood barrels. Thus, the use of oak chips in white wines may be advantageous. The wines steeped with the oak chips improved their acceptability rating 2 points on a scale of 9.
Selection of low swelling materials for protein adsorption from white wines
Authors: Sarmento Miguel R. , Oliveira Jorge C. , Boulton Roger B.
Published: March 2003

Summary The protein adsorption capacity of different materials was evaluated to assess their potential efficacy as alternative adsorbents for the removal of proteins from wines, with the purpose of finding suitable low‐swelling materials that could be used in a percolated bed. The adsorbents tested were thermally treated sodium bentonite, low‐swelling adsorbing clays, ion exchange resins and other protein adsorbents (silica gel, hydroxyapatite and alumina). The materials were evaluated by analysing both the capacity to stabilize untreated white wines, according to a heat test, and by characterizing the adsorption isotherms of bovine serum albumin (BSA) in a model wine (water, ethanol and K‐bitartrate). Breakthrough curves in a packed bed were determined experimentally for some materials, showing the influence of the adsorption isotherm shape. Some ion‐exchange resins showed a favourable behaviour and have good potential as alternative adsorbents.
Effects of ripening conditions on the texture of Gouda cheese
Authors: Bertola Nora C. , Califano Alicia N. , Bevilacqua Alicia E. , Zaritzky Noemi E.
Published: March 2003

Summary The effects of ripening temperature, type of packaging film and storage period before packaging were related to the degree of proteolysis and the texture of Gouda cheese, so as to determine the optimum ripening conditions. Gouda cheeses from a local plant were subjected to different ripening conditions. A factorial design of 23× 5 was used, where the three factors selected in two levels were: (1) time of storage before packaging, 4 and 10 days, (2) ripening temperature, 10 and 20 °C and (3) plastic film, BK1 and BK5 (Grace, Quilmes, Argentina). Ripening time was a fourth factor analyzed; sampling times were 15, 25, 35, 49 and 70 days after production. Cheeses traditionally ripened (without packaging) were also analyzed. Water content and pH were determined. Nonprotein nitrogen (soluble in 12% trichloracetic acid (TCA)) was quantified by the Kjeldhal method. Cheese texture was analyzed by compression and relaxation tests which were done by using an Instron Universal Testing Machine (Instron Corp., Canton, MA, USA). The pH and water content of cheeses which ripened at 20 °C were lower than the corresponding ones ripened at 10 °C. Only ripening time and temperature had a significant effect on water content, nonprotein nitrogen concentration and rheological parameters. Results show that texture properties of Gouda cheese ripened in plastic films with low gaseous permeability are similar to those of traditionally ripened Gouda. Texture development was accelerated by increasing the storage temperature.
The sensory quality of chicken and potato products prepared using cook–chill and sous vide methods
Authors: Church Ivor J. , Parsons Anthony L.
Published: March 2003

Summary This study examined the effects of sous vide (i.e. vacuum packaging) upon the sensory characteristics of chicken breast and of sliced potatoes in cream both immediately after cooking and following subsequent chilling, chilled storage and reheating. Cooking was to a range of end point temperatures (70 °C for 2 minutes, 80 °C for 10 minutes, 80 °C for 30 minutes) and chilled storage was for 2,5 or 7 days at 5 °C. The products were evaluated by separate sensory panels, each comprising either 25 or 10 trained assessors using attribute scaling methods. With both 80 °C heat treatments, sous vide significantly increased the flavour intensity of both products (P < 0.05) and the juiciness and moistness of the chicken and potato respectively (P < 0.05) compared to nonvacuum packed freshly cooked products. In general, higher hedonic scores were associated with higher flavour and juiciness scores for chicken and with higher flavour and moisture scores for potato. The hedonic appeal results indicate that, contrary to what has been widely assumed, these changes may not always be desirable in terms of product acceptability. The data also indicate that, in some products, the heat treatments necessary to ensure microbiological safety cause an appreciable loss of sensory quality.
Investigation of some physical characteristics of plant structures which are used as sources of pectic substances
Authors: Panchev Ivan , Karageorgiev Stefan
Published: March 2003

Summary We have investigated the physical parameters characterizing the porous structure of dried apple and orange peels, which are sources of pectic substances (PS). Mercury and nitrogen porosimetry were used to obtain quantitative data describing the characteristic diameter of the pores (dchar). Normally the diameter is between 0.13 and 0.39 μm for the apple samples, depending on the cultivar and treatment, and dchar˜ 0.27 μm for the orange samples. The total surface area of the capillaries (Stot) for the apple samples is in the range 7.18–25.52 m2g–1, and is 6.86 m2g–1 for the orange samples. The total density (ρtot) for the apple samples is 142.6–661.2 kg.m–3, and 684.4 kg.m–3 for the orange samples. The skeletal density for the apple samples is 226.8–864.4 kg.m–3, and 997.5 kg.m–3 for the orange samples. The porosity (ε) varies from 23.5% to 37.12% for the apple samples, and is 31.4% for the orange samples. The scanning electron microscopy investigation confirmed the conclusions from the mercury porosimetry that both sources of PS have a complex capillary‐porous structure. The latter structure includes pores with different shapes and dimensions, connected with each other in an unspecified manner. We present a suggested description of the kinetics of the water‐binding capacity in dried apple and orange peels, using the exponential equation q = q∞(1−e−kt). The values obtained for the kinetic parameters k and q∞ are: q∞ = (2.78 ± 0.02) g/g and k = (2.60 ± 0.13) × 10–3 s–1 for the apple peels, and q∞ = (4.62 ± 0.17) g/g and k = (3.23 ± 0.16) × 10–4 s–1 for the orange peels. The results obtained enable the development of theoretical models describing the processes of extraction of PS, and the construction of machines to be used in the PS extraction.
Differentiation of smoked Salmo salar, Oncorhynchus mykiss and Brama raii using the nuclear marker 5S rDNA
Authors: Carrera Esther , García Teresa , Céspedes Ana , González Isabel , Fernández Alicia , Asensio Luis M. , Hernández Pablo E. , Martín Rosario
Published: March 2003

PCR amplification of 5S rDNA was applied to differentiate smoked samples of Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss) and bream (Brama raii). Contiguous divergent primers for the conserved coding region of the 5S rRNA gene allowed species‐specific amplification of tandemly arranged units of the 5S rDNA in these three related species. Thus, the 5S rDNA genetic marker may become very useful for inspection programmes intended to assess the species identity of smoked products.
Modelling non‐Newtonian two‐phase flow in conventional and helical‐holding tubes
Authors: Sandeep K. P. , Zuritz Carlos A. , Puri Virendra M.
Published: March 2003

Summary The research described in this communication was undertaken to test the hypothesis that the fluid mechanics and heat‐transfer aspects involved in aseptic processing could be modelled. In order to do this, a finite difference FORTRAN program (using the fourth‐order, four‐stage explicit Runge–Kutta method) was written by the authors to compute the velocity of fluid elements and particles during fully 3‐dimensional flow in conventional and helical‐holding tubes. The effect of particles on the fluid‐flow field and the interaction between particles was taken into account during the modelling. Simulation results showed that an increase in specific gravity, tube diameter or coil diameter resulted in an increase in the residence time of the particles, while an increase in the flow rate decreased the residence time of the particles. An increase in the particle diameter or the flow rate narrowed the Residence Time Distribution (RTD) of the particles, while an increase in specific gravity or the tube diameter increased the RTD of the particles.
Determination of carbamate pesticides by a cholinesterase‐based flow injection biosensor
Authors: Lee Hye‐Sung , Kim Young‐Ah , Chung Duck Hwa , Lee Yong Tae
Published: March 2003

A potentiometric flow injection‐type biosensor developed in our laboratory was used for the determination of carbamate pesticides. The principle of the biosensor is based on the inhibition of enzyme by pesticides, which is dependent on the concentration of the pesticides present. The sensor system consisted of a reactor with acetylcholinesterase immobilized on controlled pore glass and a detector with tubular H+‐selective membrane electrode. The sensor protocol established was applied to the analysis of nine carbamate pesticides. All the pesticides at 10−6 M inhibited the sensor enzyme, demonstrating the utility of the developed method. Treatment of the inhibited enzyme with pyridine‐2‐aldoxime restored nearly all of the enzyme activity allowing repeated use of the sensor. Calibration curves for carbaryl and carbofuran over the concentration range 10−11–10−4 M were obtained. The lower detection limits were 10−10 M and 10−11 M, respectively.
Deep fat frying characteristics of chickpea flour suspensions
Authors: Bhat Keshava K. , Bhattacharya Suvendu
Published: March 2003

Chickpea (Cicer arietinum) (Bengal gram) flour suspensions are widely used in the preparation of oriental traditional snacks and sweets. We investigated the frying characteristics of small and large boondi, a traditional product made by deep fat frying the droplets of chickpea flour suspensions. The rate of water loss during frying was much higher than that of oil uptake. Towards the end of frying, the bulk densities of small and large boondis were similar and remained constant. The analysis of microstructure of the product indicated that there were large pores and vacuoles inside, whereas the outer surface remained fairly smooth with fewer smaller pores. The colour changes during frying were described in terms of tristimulus values (brightness, hue and chroma) and yellowness, of which brightness decreased markedly; the colour of the product changed from bright yellowish orange (raw batter) to dull orange (finished product).
Gelatinization kinetics of amaranth starch
Authors: Resio Andrea Calzetta , Suarez Constantino
Published: March 2003

The influence of the water:starch ratio and heating rate on the gelatinization of amaranth starch was investigated using differential scanning calorimetry. Onset and peak temperatures did not vary significantly with increase of water content, whereas the completion temperature decreased by more than 14 °C when the water content was in excess. A linear relationship was found between moisture content and gelatinization enthalpy for water:starch ratios between 0.81:1 and 2:1. From this relationship the minimum level of water necessary to initiate gelatinization was calculated. For water::starch ratios over 3:1, the enthalpy of gelatinization reached a maximum value. More rapid heating resulted in an increase of the peak and completion temperatures, as well as the gelatinization energy. Heating rates above 10 °C min−1 gave the maximum energy requirements for the completion of gelatinization in an excess of water. The kinetics of gelatinization of amaranth starch was analysed from the DSC traces. A simple mathematical model was tested to evaluate the kinetic parameters. It was shown that in an excess of water and for heating rates above 10 °C min−1, gelatinization followed first‐order kinetics with n varying from 0.91 to 0.93. The activation energy was in the range of 157–185 kJ mol−1. However, the present analysis did not allow for the determination of the kinetic parameter values over the whole gelatinization range.
Composition, soaking, cooking properties and thermal characteristics of starch of chickpeas, wrinkled peas and smooth peas
Authors: Klamczynska Beata , Czuchajowska Zuzanna , Baik Byung‐Kee
Published: March 2003

We investigated both the distribution of protein, ash and starch in legume (chickpeas, smooth and wrinkled peas) cotyledons, and the soaking and cooking characteristics, including gelatinization and retrogradation, of the starch. There were large differences in composition between different types of legumes and also between the outer and inner parts of legume cotyledons. Wrinkled peas exhibited much higher water absorption during prolonged soaking and there were higher hardness value determined for cooked seeds compared with chickpeas and smooth peas. While the hardness of cooked seeds decreased continuously as cooking time increased to 110 min, all legume starch was fully gelatinized after cooking for 70 min.
Effect of glutenin subfractions on bread‐making quality of wheat
Authors: Jood Sudesh , Schofield J. David , Tsiami Amalia A. , Bollecker Sophie
Published: March 2003

Five glutenin subfractions (R2–R6) were extracted by sequential centrifugation and addition of sodium chloride, from defatted flours of three wheat cultivars viz. Aubaine (extra‐strong), Hereward (strong) and Riband (weak). Seven minutes mixing time was used to carry out fractionation on the basis of depolymerization of glutenin macropolymers (GMP) by using a 2‐g Mixograph traces. Depolymerization of GMP occurred at much higher rates in dough of weak cultivars compared with strong and extra‐strong cultivars. Protein content was also estimated in GMP (SDS‐unextractable) and supernatant (SDS‐extractable). Extra‐strong cv. Aubaine contained maximum amount of all the glutenin fractions (R2–R6) followed by strong cv. Hereward and weak cv. Riband. Polypeptide compositions of different glutenin fractions were determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS–PAGE) under reduced and unreduced conditions, followed by densitometric scanning of stained patterns. The pattern areas of reduced fractions were divided into subareas representative of three main protein classes: high molecular weight (HMW) glutenin subunits; ω‐gliadins and a mixture of low molecular (LMW) glutenin subunits and α, β and γ‐gliadins. The amounts of various subunits were proportionate according to the molecular weight of the fractions in each cultivar. The ratio of HMW‐glutenin subunits to the LMW‐glutenin subunits in each cultivar were found to decrease with the fractionation from R2 to R6. Bread‐making quality of three cultivars was also assessed by adding various fractions to a base flour and measuring mixograph peak development time and loaf volume in an optimized baking test. The quality of bread prepared from flour of weak cv. Riband was improved significantly by the addition of HMW fraction (R2) when measured in terms of loaf volume. However, the addition of LMW fraction (R5 + R6) did not cause any appreciable improvement in bread quality over control. On the other hand, addition of HMW fraction (R2) in the flour of good bread wheat cv. Hereward caused adverse effects on the bread‐making quality by disturbing the viscoelastic properties. Supplementation of R2 fractions in extra strong wheat cv. Aubaine caused marginal reduction in loaf volume over control. Therefore, the precise proportion present of the two classes of subunit is essential to achieving a proper balance between elastic and viscous properties.
A viewpoint of mucosal immunity in relation to early feeding method
Authors: Ogundele Michael Oladipo
Published: March 2003

Atopic diseases are common health problems in society and their incidence is increasing unabated. A number of studies in animal models have shown that antigen‐specific IgE suppression could be induced for the treatment of allergic disorders. Many of the present therapeutic strategies in children have not been entirely successful and early breastfeeding could provide a practicable means of helping the affected children. An overview of the mucosal immune system is hereby presented to explain the natural mechanisms involved in protecting organisms from allergic reactions to food and other non‐harmful antigens presented at the mucosal surfaces. The protective role of early breastfeeding in modulating this natural phenomenon is emphasized. The undeniable limitations of breastfeeding in the management of some peculiar cases of childhood dietary protein intolerance are also highlighted.
Inhibition of endive (Cichorium endivia L.) polyphenoloxidase by a Carica papaya latex preparation
Authors: De Rigal David , Cerny Muriel , Richard‐Forget Florence , Varoquaux Patrick
Published: March 2003

When endive polyphenoloxidase (PPO) was incubated with a crude papaya latex extract, it rapidly lost its activity. Inactivation was ascribed to thermostable nonenzymatic factors of low molecular weight. These factors were partially purified by a two step protocol including gel filtration chromatography on Biogel P2 and ion exchange chromatography using DEAE Sephadex A25. The PPO‐inactivation rate was first order, when either inactivating agent or proton concentration was evaluated. Inactivation could be partially reversed by CuSO4, which suggested that the inactivating factor(s) bound to the copper site of the enzyme. On a more rapid time scale than inactivation, papaya latex extract acted also as a weak noncompetitive PPO inhibitor.
Microstructural analysis of frying potatoes
Authors: Bouchon Pedro , Aguilera José M.
Published: March 2003

Frying induces major structural changes in the surface of foods influencing oil uptake. This work discusses the use of several different methods of microscopy as well as techniques of image analysis to study frying at the microstructural level. Hot‐stage video microscopy was instrumental in assessing geometrical changes in cells of potato tissue and in starch in real time. The swelling of starches inside cells appeared to be retarded compared with that in starch suspensions. Confocal laser scanning microscopy (CLSM) permitted ‘optical’ sectioning of the crust, revealing that oil was located in the interior in pockets or surrounding intact cells. The manipulation of microscopy data by image processing is also presented.
Optimization of the production of acetylated distarch adipates using the novel software ‘MULTIPLEX’
Authors: Mali S. , Silva R. A. S. , Grossmann M. V. E. , Silva R. S. F. , Borsato D.
Published: March 2003

Acetylated, cross‐linked and pregelatinized cassava starches were produced in a single‐screw extruder with different moisture contents (180, 220 and 260 g kg–1), reagent (adipic acetic mixed anhydride) concentrations (4, 11 and 18 g kg–1) and screw speeds (100, 130 and 160 r.p.m.). The acetylation, cross‐linking and pregelatinization increased cold viscosity (CV), water absorption index (WAI) and gel hardness, it also reduced gel cohesiveness, paste clarity and retrogradation of the modified‐starches compared with control samples (CSs). A novel microcomputer program called MULTIPLEX was developed for the optimization of the process. The optimization process maximized CV, WAI, gel hardness and paste clarity, and minimized gel cohesiveness and retrogradation of the modified‐starches. The optimum conditions were moisture of 240 g kg–1, reagent concentration of 4 g kg–1 and screw speed of 100 r.p.m. Experimentally determined values for all responses found in products processed under the optimum conditions were very close to the predicted values and this confirmed the validity of predicted models.
Food biotechnologies and retail ethics: a survey of UK retailers’ views on the use of two dairy technologies
Authors: Millar K. M. , Tomkins S. M. , Mepham T. B.
Published: March 2003

Consumer attitudes to biotechnologies will significantly influence their use in the food industry. However, retailers also have a powerful position in the food system and play an influential role in defining and framing the use of biotechnology. This raises a number of ethical issues. This case study of the role of retailer behaviour in technology use and acceptability examined the implications of retailers’ attitudes for the use of two dairy technologies, bovine somatotrophin (bST) and automatic milking systems (AMS), and for any effects these attitudes might have upon other interest groups. Responding retailers viewed bST as ethically unacceptable, whereas AMS use was characterised as acceptable to most. Retailers appeared to apply a precautionary approach to these two biotechnologies. Although the nature of retailer social responsibility is ill‐defined, their powerbroker position would seem to highlight a need to explore these ethical issues further.
Risk and food: environmental concerns and consumer practices
Authors: Halkier Bente
Published: March 2003

Environmental risks related to food consumption produce needs among consumers to handle such risks through their consumption practices. Consumers’ ways of coping with risks are dependent on the social relations of everyday life, of which consumption practices are a part. Risk‐handling in food consumption is socio‐culturally broader than the cognitive rationality assumed in expert knowledge and administrative procedures on risk and risk‐handling. Likewise, risk‐handling in food consumption is also characterized by ambivalences. The objective of the article is to show that an important social and cultural source of ambivalence in consumers’ handling of risk in food consumption comes from food consumption practices being caught in the tension between desire and control. The article proposes a heuristic theoretical device, called ‘the contested space of the body’, which is used to discuss the bodily dimension of consumer risk‐handling. This is based on a Danish empirical study of parents with small children. A typology of consumers’ risk‐handling is presented which differs from traditional typologies of consumer segments by allowing for overlaps and shifts between the individual positions in the typology. The three types of risk‐handling are the worried, the irritated and the pragmatic. The results suggest that in worried risk‐handling control marginalizes desire, in irritated risk‐handling desire is openly in conflict with control, and in pragmatic risk‐handling relief from the contested space of the body is attempted.
Stochastic approach to the modelling of water losses during osmotic dehydration and improved parameter estimation
Authors: Cunha Luís M. , Oliveira Fernanda A. R. , Aboim Adriana P. , Frías Jesús M. , Pinheiro‐Torres Andreia
Published: March 2003

The kinetics of water loss in the apple cultivar Golden during osmotic dehydration in sucrose solutions was studied. Two sets of experiments were performed, each following a full factorial design at five levels for sucrose concentration (0.45–0.65 w/w) and temperature (20–40 °C). The first set was designed to assess the adequacy of the Weibull model to describe water losses, whereas the second set was designed to improve parameter estimation, based on theD‐optimal design concept. The model provided good fits to the experimental data, and theD‐optimal design yielded improved parameter precision. The shape parameter of the model was 0.5 and statistically independent of both temperature and sucrose concentration. The rate constant ranged between 0.004 and 0.012 min−1and increased with temperature following an Arrhenius type relationship, with the activation energy increasing linearly with concentration. The interactive effects of temperature and sucrose concentration on the process kinetics were analysed.
Effect of moderate electric field pulses on the diffusion coefficient of soluble substances from apple slices
Authors: Jemai Abdel Basset , Vorobiev Eugene
Published: March 2003

The effects of a moderate electric field pulse (MEFP) on the diffusion coefficient of soluble substances from apple slices have been investigated. The apparent diffusion coefficient,D, was studied for both thermally and electrically treated samples. For thermally treated samples, the variation ofDthas a function of temperature followed an Arrhenius type kinetic with two diffusion regimes: (i) without thermal pretreatment (Ea ≈ 28 kJ mole–1) and (ii) after plasmolysis pretreatment (Ea ≈ 13 kJ mole–1). In the case of electrically treated samples, only one regime was observed, with an intermediate activation energy (Ea ≈ 20 kJ mole–1). Furthermore, it was found that an electrical pretreatment with moderate temperature elevation (10–15 °C) combined with a low thermal treatment, significantly enhanced the diffusion coefficient (Del) compared with reference values. For instance, after a standard MEFP treatment (500 V cm–1, 1000 pulses, 100 μs duration)Delwas 3.9 × 10–10 m2 s–1at 20 °C compared with reference values of 2.5 and 4.4 × 10–10 m2 s–1for untreated and denatured samples, respectively, and 13.4 × 10–10m2 s–1at 75 °C compared with 10.2 × 10–10 m2 s–1for thermally denatured samples. This indicates that an electrical treatment has a greater effect on the structure and permeability of apple tissue than thermal treatment.
Basmati rice: a review
Authors: Bhattacharjee Paramita , Singhal Rekha S. , Kulkarni Pushpa R.
Published: March 2003

India contributes about one‐third of the world acreage under rice. Rice is available in over 5000 varieties, of which Basmati rice occupies a prime position on account of its extra long superfine slender grains, pleasant, exquisite aroma, fine cooking quality, sweet taste, soft texture, length‐wise elongation with least breadth‐wise swelling on cooking and tenderness of cooked rice. This article reviews the quality and aroma traits of Basmati rice, particularly the varieties grown in different parts of India and Pakistan, the agronomy, breeding and physiology of the grain, the trade scenario, Agmark grade designation for export and the US patent of new hybrid strains of Basmati.
Anti‐oxidant activity and total phenolic content of some Asian vegetables
Authors: Kaur Charanjit , Kapoor Harish C.
Published: March 2003

The anti‐oxidant activity of extracts from 36 vegetables was evaluated by using a model system consisting of β‐carotene and linoleic acid. The total phenolics of the extracts was determined spectrophotometrically according to the Folin–Ciocalteau procedure and ranged from 34 to 400 mg (100 g)−1 on a fresh weight basis. Mint, aonla, black carrots, chenopodium, fenugreek, kachnar and ginger had high phenolic contents. The anti‐oxidant activity expressed as per percent inhibition of oxidation ranged from a high of 92% in turmeric extracts to a low of 12.8% in long melon. Other vegetables found to have high anti‐oxidant activity (>70%) were kachnar, aonla, ginger, fenugreek, mint, beetroot, black carrots, Brussels sprouts, broccoli, lotus stem, yam, coriander and tomato. Anti‐oxidant activity correlated significantly and positively with total phenolics (r2=0.6578, P < 0.05). The results indicate that vegetables containing high phenolics may provide a source of dietary anti‐oxidants.
Performance of virgin olive oil and vegetable shortening during domestic deep‐frying and pan‐frying of potatoes
Authors: Andrikopoulos Nikolaos K. , Kalogeropoulos Nick , Falirea Angeliki , Barbagianni Maria N.
Published: March 2003

The performance of virgin olive oil and a commercial vegetable shortening was investigated during 10 successive pan‐fryings of potatoes at 180 °C for a total period of 60 min and during 10 successive deep‐fryings at 170 °C for a total period of 120 min. These are typical conditions of Greek domestic cooking. For both the oils tested the effect of pan‐frying on K232, K268, K316, α‐tocopherol, total polar artefacts, Rancimat induction times, octanoic acid formation and linoleic acid decomposition was worse than the effect of deep‐frying on the same variables. The same was true for visible spectrum and total phenols in virgin olive oil. No systematic variations of oleic acid, refractive index and trans‐isomers of fatty acids were detected. None of the oils reached the limit of 25–27% total polar artefacts. Both oils performed similarly during pan‐frying, while virgin olive oil performed better during deep‐frying. A very strong correlation between octanoic acid formation and total polar artefacts in the whole data set was observed.
The effects of using packaging films with different permeabilities on the quality of Korean fermented red pepper paste
Authors: Lee Dong Sun , Jang Jae Deok , Hwang Yong Il
Published: March 2003

Korean fermented red pepper paste was packaged with four plastic films of different gas permeabilities and stored at 13 °C. During the storage, package weight, volume expansion, microbial flora, surface colour, pH and acidity were measured. Highly permeable film, such as low density polyethylene, alleviated the volume expansion; however, this packaging also supported higher yeast count on the paste for longer periods and caused higher weight loss when compared with other plastic films. There was also a concern that loss of volatile acids was greater for this type of packaging. On the other hand, use of barrier packaging films, such as Al‐laminate and nylon laminate, resulted in high volume expansion because of low permeation of carbon dioxide from the package. Plastic films with appropriate gas permeability, such as coextruded multilayer polyamide, may be the most practical choice based on consideration of both volume expansion and quality retention of the fermented paste.
Formation of sunflower oil emulsions stabilized by whey proteins with high‐pressure homogenization (up to 350 MPa): effect of pressure on emulsion characteristics
Authors: Desrumaux Anne , Marcand Julie
Published: March 2003

A new ultra‐high‐pressure homogenizer was used to make very fine oil in water emulsions. The effect of pressures up to 350 MPa on sunflower oil (20%) in water emulsions was studied. The emulsifier used was whey protein concentrate (1.5%). The properties of the emulsions were characterized by laser light scattering (droplet size distribution) and coaxial cylinders rheometry (rheological behaviour). The protein adsorption fraction was obtained by a spectrophotometric method using bicinchoninic acid reagent.

Significant modifications in the structure and the texture of the emulsions were observed as the pressure increased. No change was revealed by polyacrylamide gel electrophoresis of the whey protein within the pressure range studied. Microdifferential scanning calorimetry scans indicated that the changes of the structural and textural properties may be because of changes in the protein conformation.
Evaluation of physico‐chemical characteristics and microstructure of tofu containing high viscosity chitosan
Authors: Kim Meera , Han Jin‐suk
Published: March 2003

Tofu, containing high viscosity chitosan dissolved in a δ‐gluconolactone solution, was prepared and physico‐chemical properties, microstructure, textural properties and sensory characteristics were investigated. Moisture content and pH of the chitosan tofu were slightly lower than those of the control tofu. The textural properties of tofu such as hardness, cohesiveness, gumminess and chewiness measured by an instrumental method were not significantly changed by the addition of chitosan to tofu. Springiness of chitosan tofu, however, was significantly higher than that of the control tofu. All characteristics except the roasted nutty aroma and yellowness in the sensory evaluation, did not exhibit significant differences between the chitosan tofu and control tofu. Therefore, the quality of tofu was little affected by the addition of the chitosan content employed in this experiment.
Evaluation of tenderness in prawns (Machrobrachium rosenbergii) marinated in various salt and acid solutions†
Authors: Xiong Shuling , Xiong Youling L. , Blanchard Suzanne P. , Wang Baowu , Tidwell James H.
Published: March 2003

Freshly harvested prawns (Machrobrachium rosenbergii), with shell removed, were marinated in salt (NaCl, CaCl2) and acid (lemon juice, citric acid, tripolyphosphate) solutions to determine the effects of marination on properties related to the texture of raw and cooked muscle. Sodium chloride and citrate solutions (pH 7.0) slightly increased (P < 0.05) the tenderness of cooked prawn, when compared with water‐marination control. Tripolyphosphate (pH 7.0) showed no effect, while CaCl2 (pH 7.0), citric acid (pH 3.0), and lemon juice (pH 3.0) increased (P < 0.05) the muscle toughness. The decrease of meat tenderness by some of the marinade treatments was attributed to decreases in protein solubility during marination and to cooking losses.
Recognition of liquid and flesh food using an `electronic tongue'
Authors: Rudnitskaya Andrey Legin Alisa , Seleznev Boris , Vlasov Yuri
Published: March 2003

An electronic tongue comprising thirty potentiometric chemical sensors and pattern recognition tools for data processing was used for the analysis of mineral waters, coffee, soft drinks and flesh food, namely fish. The electronic tongue appeared to be capable of distinguishing between different sorts of beverages: natural and artificial mineral waters, individual and commercial brands of coffee, and commercial and experimental samples of soft drinks containing different sweeteners. A quantitative correlation between human perception and `electronic tongue' output was obtained. Taste parameter assessments produced by a professional taste panel was used for `electronic tongue' calibration. It was found that the `electronic tongue' is capable of distinguishing sea water and freshwater fish and monitoring their spoilage.
Methodology to study visual preference for horticultural products using quantitative imaging techniques and latent class segmentation
Authors: Coppenolle Hans , Paulus I. , Schrevens E.
Published: March 2003

A methodological concept is proposed to study visual preference for horticultural products using quantitative imaging techniques and latent class segmentation. Chicory, a typical Belgian vegetable, serves as a model product. A 23 full factorial pairwise comparison experiment was designed to study visual preference for length, width and ovality of a traditional fresh, high‐quality chicory product using a computer based image system. Twenty respondents chose which of two samples was preferred in all twenty‐eight pairwise combinations of eight constructed image sequences. The consistency of the respondents and agreement between respondents was evaluated. Traditional techniques for analysis of pairwise comparison data were compared with a latent class binomial logit model. This approach relaxes the traditional assumption that the same model holds for all respondents by simultaneously relating choices to quality descriptors for different consumer segments.
Use of 1‐acetoxypinoresinol to authenticate Picual olive oils
Authors: Brenes M. , García A. , Rios J. J. , García P. , Garrido A.
Published: March 2003

Picual olive oils may represent 25% of the world olive oil production. This monovarietal oil is highly valued from a nutritional viewpoint because of its high content of monounsaturated acid and polyphenols. This study reports a method to authenticate virgin olive oils of the Picual variety. The method was based on the very low content of the lignan 1‐acetoxypinoresinol in these oils. The compound, as well as the other phenolic substances, was extracted from oil by using N,N‐dimethylformamide (DMF), the extract was washed with hexane and nitrogen was bubbled into the solution. The identification and quantification of the lignan used HPLC to separate, followed by UV, electrochemical, fluorescence and mass spectrometry detection or gas chromatography (GC) coupled to a mass spectrometry detector. UV detection offered low sensitivity and peaks coeluting with 1‐acetoxypinoresinol were also observed. Mass spectrometry detection clearly discriminated between olive oils of Picual variety and other Spanish varieties. However, lignans show a very high response to fluorescence excitation, this detector is cheaper than mass spectrometry detectors and therefore it was considered as more appropriate for industrial uses. Thus, the latter method allowed discrimination between thirty‐eight Picual olive oils and eight oils of the Hojiblanca, Cornicabra, Empeltre and Arbequina varieties. The paper also demonstrated the possibility of analysing all the phenolic compounds in virgin olive oil by fluorescence. Using this technique an easy methodology to authenticate Picual olive oils was developed.
A review of the potential impact of dietary endocrine disrupters on the consumer
Authors: Shaw Ian , McCully Stuart
Published: March 2003

Endocrine disrupters, in particular xenoestrogens, have been implicated in a broad array of environmental effects. Their presence in food, either as natural components (e.g. phytoestrogens) or chemical contaminants (e.g. xenoestrogenic pesticides) have been implicated in a number of human effects (e.g. declining sperm count). We present calculations which ranks the importance of the different classes of dietary endocrine disrupters, and show that only phytoestrogens are likely to have a health impact.
Finding critical variables for food heating
Authors: May Nicholas S. , Chappell Philippa
Published: March 2003

It is important to identify intrinsic critical variables affecting the heating of products in processes aiming to achieve microbiological safety. The Taguchi method has enabled the identification of critical variables for heating of a complex canned product (spaghetti in a sauce) in an agitated process in a water immersion retort. Within the ranges tested one of eleven variables exerted a large effect upon product heating. The most important variable was the concentration of tomato puree in the sauce, which affected the process F0 by15–18 min between the two concentrations tested.
Parboiling of rice. Part II: Effect of hot soaking time on the degree of starch gelatinization
Authors: Miah M. A. Kaddus , Haque Anwarul , Douglass M. Paul , Clarke Brian
Published: March 2003

A differential scanning calorimetric study was done on raw and parboiled rice to determine the degree of gelatinization. Unparboiled rice absorbed the highest amount of endothermic heat, the enthalpy change gradually decreasing with increasing hot soaking time. The highest degree of gelatinization was achieved when the paddy was soaked for 120 min at 80 °C. With increasing degree of gelatinization, the yield point in a compression test also increased. During the parboiling process internal fissures were healed, resulting in higher head rice yield during milling.
The glyceridic and nonglyceridic constituents of virgin olive oil after use of a novel method of enzyme extraction
Authors: Ranalli Alfonso , Pollastri Luciano , Contento Stefania , Iannucci Emilia
Published: March 2003

Summary The composition of three virgin olive oil varieties (Caroleo, Coratina and Leccino) was investigated after extraction with a new enzyme processing aid called Bioliva. Comparisons with reference oils extracted without using the biological preparation were made. The oils extracted by enzymes showed the following features: (i) higher contents of total phenols, o‐diphenols, major free and hydrolysable phenols, tocopherols, chlorophylls, pheophytins (Mg‐free chlorophyll derivatives), β‐carotene, major xanthophylls (lutein, violaxanthin and neoxanthin), agreeable volatiles, long‐chain aliphatic alcohols and superior triterpene alcohols; (ii) lower contents of disagreeable volatiles; (iii) higher sensory scoring and resistance to autoxidation; (iv) higher values of Naudet's integral colour index, carotenoid colour index, chroma and 1,2‐diglycerides/1,3‐diglycerides ratio and (v) lower values of lightness. These findings suggested that the oil's analytical pattern was meaningfully improved following this novel enzyme treatment.
Use of electron spin resonance measurements on irradiated sperma lentil seeds to indicate accidental irradiation
Authors: Korkmaz Mustafa , Polat Mustafa
Published: March 2003

Summary The results of electron spin resonance studies on γ‐irradiated micro‐ and macrosperma lentil seeds are reported. Spectra of non‐irradiated intact sperma were composed of an equally spaced sextet originating from the presence of Mn2+ ions and a single weak resonance line. Irradiation produced a linear increase in the radical signal intensity in the radiation dose range (0.5–5 kGy) studied, without affecting the Mn2+ signal. Signal intensities of both sperma followed compound exponential decay curves originating from the presence of three different radical species. Heating the sperma cause irreversible decreases in both radical and Mn2+ signal intensities. Two radical species, described in the present work, and a radical of unknown origin were used to explain the experimental results.
Effect of copper on oxidation of (+)‐catechin in a model solution system
Authors: Es‐Safi Nour‐Eddine , Cheynier Véronique , Moutounet Michel
Published: March 2003

Summary Autoxidation of (+)‐catechin in a model solution system, containing cupric ions, was monitored by high‐performance liquid chromatography with diode array detection. The rate of (+)‐catechin oxidation and the extent of browning increased with the copper concentration, showing an effect of copper on browning of flavanols. The progression of the reaction showed that the appearance of new compounds, which were initially absent in the mixture, was concomitant with (+)‐catechin decrease. Numerous reaction products, including both colourless compounds and pigments absorbing at 440, 460 and 550 nm, were detected. Among the colourless derivatives, four dimeric compounds, consisting of two catechin units linked by a carboxymethine bridge, were detected. Their formation involved the condensation of flavanols, mediated by glyoxylic acid, following a mechanism similar to that previously observed with iron. The yellowish compounds that were detected were identified as xanthylium salts and their corresponding esters, showing absorption maxima at 440 and 460 nm, respectively. Comparison of the results obtained with those reported with iron showed that copper ions play similar roles in enhancing the oxidation rate of (+)‐catechin and flavanols.
Effects of incubation and polyphenol oxidase enrichment on colour, fermentation index, procyanidins and astringency of unfermented and partly fermented cocoa beans
Authors:   Misnawi, Jinap S. , Jamilah B. , Nazamid S.
Published: March 2003

Incubation of unfermented and partly fermented cocoa beans in acetate buffer, pH 5.5, at 45 °C increased yellowness, total colour differences and fermentation index value of the cocoa bean powders and decreased cocoa procyanidins (monomers to pentamers), and their astringency. Fermentation index and (–)‐epicatechin content, equivalent to those of fully fermented beans, were reached by unfermented beans after 4–8‐h incubation, but not by partly fermented beans even after 16 h. During incubation of partly fermented cocoa beans enriched with polyphenol oxidase, yellowness and fermentation index value were increased, whilst (–)‐epicatechin was decreased. Tyrosinase had a less significant effect in yellow colour formation, but showed a significant reduction of (–)‐epicatechin and increase in fermentation index compared with crude cocoa polyphenol oxidase. However, both enzymes have similar effects on procyanidin degradation and astringent taste reduction. Incubation of cocoa beans for 16 h increased the cut test score of unfermented and partly fermented beans by 50 and 30%, respectively.