bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nephelometric study of salivary protein–tannin aggregates
Authors: Freitas Victor de , Mateus Nuno 
Published: October 2002

AbstractGrape seed procyanidins were fractionated through different degrees of polymerisation, and human saliva was purified and separated into two fractions: one was mostly α‐amylase and the other was essentially proline‐rich proteins (PRPs). The interaction of these proteins with the procyanidin compounds was assayed using nephelometry, and the influence of several factors was investigated, such as degree of polymerisation, pH and concentrations of both protein and tannin. The same experiments were performed with bovine serum albumin (BSA). The amount of insoluble aggregates, resulting from the formation of polyphenol–protein aggregates, increased quickly up to a maximum value which thereafter remained practically unchanged. pH was set at 5.0 for all further assays, since it was the nearest value to that encountered in human saliva (pH 5.6–7.9), where proteins were stable and had a maximum ability to bind and precipitate procyanidin oligomers. These proteins were shown to have a strong affinity for procyanidin oligomers and were unable to resolubilise the polyphenol–protein aggregates when present in excess. PRPs required a much lower content to bind all the tannins (400 µg of procyanidin oligomers) than BSA and especially α‐amylase (48, 60 and 132 µg respectively). The procyanidin's ability to bind PRPs, BSA and α‐amylase increased with its average molecular weight. This ability increased regularly for PRPs up to 4500 Da, whereas the ability to bind the globular proteins decreased beyond 3400 Da.© 2001 Society of Chemical Industry
Effect of various dietary fats and proteins on serum cholesterol level in rats
Authors: Hanczakowski Piotr , Szymczyk Beata , Furgał‐Dierżuk Iwona 
Published: October 2002

AbstractA 60 day experiment on growing rats was performed to evaluate the effect of two protein sources (casein and soybean protein isolate) and four fats (olive oil, OO; evening primrose oil, EO; linseed oil, LO; and butter, B) on plasma lipoprotein fractions: total cholesterol (TC), high‐density lipoprotein cholesterol (HDL‐C), low‐density lipoprotein cholesterol (LDL‐C) and triacylglycerol (TAG) levels. The different protein and fat sources had no influence on body weight gain of rats. Fats had no significant effect on TC and LDL‐C. Significant differences were found only in HDL‐C. OO gave the lowest (43.3 mg dl−1) and EO the highest (54.4 mg dl−1) value. Proteins had a significant influence on all lipids analysed. Soybean protein caused higher TC (78.5 vs 67.9 mg dl−1), HDL‐C and TAG levels but significantly lowered LDL‐C in the plasma of rats. These results suggest that protein has a stronger effect on cholesterol level than fat.© 2002 Society of Chemical Industry
Phenolic compounds, lycopene and antioxidant activity in commercial varieties of tomato (Lycopersicum esculentum)
Authors: Martínez‐Valverde Isabel , Periago María J , Provan Gordon , Chesson Andrew 
Published: October 2002

AbstractNine commercial varieties of tomato (Rambo, Senior, Ramillete, Liso, Pera, Canario, Durina, Daniella and Remate) produced in Spain were analysed for their lycopene content, content of phenolic compounds and antioxidant capacity. The phenolic compounds were characterised as flavonoids (quercetin, kaempferol and naringenin) and hydroxycinnamic acids (caffeic, chlorogenic, ferulic and p‐coumaric acids). Antioxidant activity was measured using the DPPH and ABTS assays. The concentrations of lycopene and the various phenolic compounds as well as the antioxidant activity were significantly influenced by the tomato variety. Quercetin, the most abundant flavonoid, was found in concentrations ranging between 7.19 and 43.59 mg kg−1 fresh weight, while naringenin levels were lower than 12.55 mg kg−1. The most abundant hydroxycinnamic acid was chlorogenic acid, with values ranging from 14 to 32 mg kg−1 fresh weight, followed by caffeic acid, while p‐coumaric and ferulic acids showed similar concentrations lower than 5 mg kg−1. The highest content of lycopene was found in Ramillete, Pera and Durina (>50 mg kg−1 fresh weight), while the concentration in the other varieties was between 50 and 30 mg kg−1, with the exception of Liso (less than 20 mg kg−1). The antioxidant activity of tomato extracts varied with the tomato variety and the assay method used. Individual compounds found to be significantly related to antioxidant capacity were lycopene and ferulic and caffeic acids, but not quercetin and chlorogenic acid.© 2002 Society of Chemical Industry
Influence of harvest time on citrus pectin and its in vitro inhibition of fibroblast growth factor signal transduction
Authors: Liu Yan , Ahmad Hassan , Luo Yongde , Gardiner Duane T , Gunasekera Richard S , McKeehan Wallace L , Patil Bhimanagouda S 
Published: October 2002

AbstractSeasonal changes in pectin content and chemical composition were studied in three anatomical layers of ‘Rio Red’ grapefruit (Citrus paradisi Macf), a currently popular cultivar in the Rio Grande Valley in Texas, USA. Fruits were harvested at intervals between August 1998 and May 1999. Pectin content in flavedo decreased throughout the season, while in albedo and segment membrane the pectin content was lowest in mid‐season (November and January). In all three layers the anhydrogalacturonic acid (AGA) content of pectin was highest in mid‐season. While the methoxyl content (MC) of pectin increased, the total neutral sugar (TNS) content of pectin decreased in all three layers throughout the season. The in vitro effect of grapefruit pectin on fibroblast growth factor (FGF)–FGF receptor (FGFR) interaction was also investigated. The strong interdependence of heparin on factor–receptor interaction provides means for identifying new antagonists of growth factor activity and thus for treatment of various diseases. Our results showed that grapefruit pectin significantly inhibited the binding of FGF‐1 to FGFR1 in the presence of 0.1 µg ml−1 heparin. Pectin of albedo from grapefruits harvested in January was the most potent inhibitor. The in vitro inhibitory activity was significantly correlated with the percentage of rhamnose. Kinetic studies revealed a competitive nature of pectin on FGF signal transduction with heparin. The observation that the biological activity of heparin can be antagonised by citrus pectin suggests that pectins should be investigated further as anti‐growth factor agents for potential health benefits.© 2002 Society of Chemical Industry
Sensory characterisation of ewe's milk cheeses using direct and indirect similarity measures: a comparison
Authors: Bárcenas Pedro , Pérez Elortondo Francisco J , Salmerón Jesús , Albisu Marta 
Published: October 2002

AbstractThe purpose of the present study is to compare several direct and indirect (profile and hedonic scores) similarity measures. Moreover, the main relationships among assessors, sensory attributes and ewe's milk cheeses have been explored using different statistical techniques. For this purpose, visual inspection and correlation coefficients among cheese sample sensory dimensions have been considered. All the solutions lead to very similar spatial configurations, except for preference data. In this case the considered techniques are very useful tools in the study of sensory attributes. Individual differences among assessors have been demonstrated to be quite high. Thus it is clear that methods that consider this variability in the data should be used, to which end, assessors should undergo specific training depending on the tests to be performed.© 2002 Society of Chemical Industry
Factor analysis of physicochemical properties of 63 rice varieties
Authors: Tan Yifang , Corke Harold 
Published: October 2002

AbstractA set of 63 Chinese‐adapted non‐waxy rice varieties of the indica and japonica subspecies was measured to extract simple indicators for rice quality evaluation. Approximate methods including amylose content (AC), gel consistency (GC), gelatinisation temperature (as measured by alkali spreading value, ASV), protein content, etc and instrumental methods including differential scanning calorimetry (DSC), viscoamylography (with a Rapid Visco‐Analyser, RVA) and texture profile analysis were adopted. Four sets of data, ie ordinary testing, flour pasting property, texture of the cooled flour gel, and visual appearance of whole milled grain and flour, were obtained and analysed for mutual relationships. Wide variations were observed in most of the measurements, eg AC (ranging from 6.3 to 28.2%), gelatinisation temperature (Tp, 65.8–83.0 °C), protein content (7.2–13.5%), pasting (peak viscosity, 92–319 RVU) and texture (hardness, 2.5–24.4 g) properties and grain appearance (grain length, 4.8–8.4 mm), to mention a few. Significant correlations were also detected among the four sets of data of the rice varieties, such as AC versus SB (setback viscosity) with a correlation coefficient of −0.73, AC versus HRD (gel hardness) of 0.73, HRD versus FRC (gel fracturability) of 0.99, etc. Generally, the instrumental measurements including DSC, pasting and texture properties were highly correlated with the three ordinarily used indicators of rice quality, ie AC, GC and ASV. However, there was a lack of correlation between pasting properties and textural parameters, implying effects on gel texture of retrogradation of starch after cooling of the paste. Six factors were computed by principal component factor analysis that explained 80% of the variation in the traits, among which amylose content‐related (30.8%), gelatinisation temperature‐related (14.9%) and grain appearance‐related (11.1%) factors were most important. Gel pasting properties evaluated by RVA, and flour colour played less important roles in explaining total variation (accounting for a combined 23% of the eigenvalue loading). This report can be used to identify predictive parameters for rapid screening of rice genotypes for eating quality.© 2002 Society of Chemical Industry
Identification of odour‐active compounds in muscle of brown trout (Salmo trutta) as affected by dietary lipid sources
Authors: Sérot Thierry , Regost Christelle , Arzel Jacqueline 
Published: October 2002

AbstractThe effect of fatty acid composition on odour‐active compounds in brown trout (Salmo trutta) muscle was evaluated. The fillets were obtained from three groups of fish fed experimental diets containing either fish oil (FO), soybean oil (SO) or linseed oil (LO). Muscle fatty acid composition was shown to be influenced by diet. Thirty‐one odorous compounds were detected by gas chromatography/olfactometry (frequency‐of‐detection method). Most of these compounds were formed by the oxidation of unsaturated fatty acids. Independently of diet, (E)‐2‐pentenal, (E)‐2‐pentenol and (E)‐2‐hexenol contribute strongly to the odour of brown trout. (E,Z)‐2,4‐Heptadienal was detected with high frequency in fish fed diets containing high levels of n‐3 PUFAs (FO and LO groups). Hexanal, (E)‐2‐hexenal and 2‐nonanol seem to contribute most to the odour of fish fed diets containing vegetable oils. Many odorous compounds were derived from the oxidation of mono‐ and di‐unsaturated fatty acids, which could be promoted by high levels of PUFAs.© 2002 Society of Chemical Industry
Analysis of vicilin (7S)‐class globulin in cocoa cotyledons from various genetic origins
Authors: Amin I , Jinap S , Jamilah B , Harikrisna K , Biehl B 
Published: October 2002

AbstractCocoa cotyledons contain vicilin (7S)‐class globulin (VCG), a major storage protein. It is the native source of oligopeptides and free amino acids which have been identified as precursors of cocoa‐specific aroma and are formed through proteolysis during fermentation. High‐resolution electrophoresis of native proteins isolated from ripe, unfermented cocoa cotyledons harvested from different cultivars was used to determine genetic differences of the genotypes. Flavour differences have been reported to exist after standard fermentation in cocoa beans harvested from various genotypes. In this paper, SDS‐PAGE and 2D IEF/SDS‐PAGE polypeptide separation patterns are shown which were separately isolated from cotyledons of various genetic origins. Cotyledons from three cultivars belonging to genetically distant varieties and a hybrid, Criollo, Forastero and Trinitario, did not reveal any analytical identity differences of VCG subunit polypeptide bands. Additionally, proteins of cotyledons harvested from three of those clones which were reported to produce genotype‐specific flavour differences in raw cocoa after standard fermentation, SCA 12, UIT1 and PBC 140, when analysed in the same way, did not indicate differences. Thus the cotyledon storage proteins from various genetically different cocoa trees are, within methodological limits, the same. We conclude that aroma differences in raw cocoa harvested from various genotypes are the result of other genetic, physiological or curing‐related factors, but are not due to genetic differences of aroma precursors derived from storage proteins.© 2002 Society of Chemical Industry
Modified atmosphere packaging of filleted rainbow trout
Authors: Giménez Begoña , Roncalés Pedro , Beltrán Jose A 
Published: October 2002

AbstractShelf‐lives of filleted rainbow trout (Oncorhynchus mykiss) packaged in over‐wrap, vacuum and gas mixture conditions and stored at 1 ± 1 °C were compared by measurement of pH, total volatile bases (TVB), hypoxanthine content, lipid oxidation (TBARS value), superficial counts of aerobic psychrotrophic flora and sensory analysis (colour, odour and flavour). The gas mixtures evaluated were 10% O2 + 50% CO2 + 40% N2, 10% O2 + 50% CO2 + 40% Ar, 20% O2 + 50% CO2 + 30% N2, 20% O2 + 50% CO2 + 30% Ar, 30% O2 + 50% CO2 + 20% N2 and 30% O2 + 50% CO2 + 20% Ar. Sensory quality deterioration was delayed and bacterial growth as well as increases in pH, TVB and hypoxanthine levels were reduced by modified atmosphere packaging (MAP). Lipid oxidation was higher in gas packages with 20 and 30% O2 than in those with 10% O2. Vacuum‐packed fillets presented the lowest TBARS values. In summary, MAP gave rise to a significant extension of shelf‐life when compared with vacuum and over‐wrap packaging. No significant differences were found between the packages containing either N2 or Ar. The best evaluated atmosphere consisted of 10% O2 + 50%CO2 + 40% N2/Ar.© 2002 Society of Chemical Industry
Simultaneous quantification of the main organic acids and carbohydrates involved in tomato flavour using capillary zone electrophoresis
Authors: Roselló Salvador , Galiana‐Balaguer Luis , Herrero‐Martínez José Manuel , Maquieira Angel , Nuez Fernando 
Published: October 2002

AbstractA capillary zone electrophoresis (CZE) procedure for the simultaneous determination of the major organic acids (oxalate, malate and citrate) and carbohydrates (fructose, glucose and sucrose) in Lycopersicon fruits is reported. Comparison of this method with routine HPLC methods indicates that the CZE method offers several attractive features (speed, resolution, sensitivity and cost) which significantly improve the determination of these compounds. Detection limits were better than 1.6 µg ml−1 for organic acids and from 13 to 24 µg ml−1 for carbohydrates; repeatabilities were better than 2.1% for migration times and between 1.4 and 7.3% for peak areas. The proposed protocol is very useful to characterise large series of tomato samples not only in breeding programmes but also in systematic and routine analysis in the tomato industry.© 2002 Society of Chemical Industry
Effects of maize grain size, shape and hardness on drying rate and the occurrence of stress cracks
Authors: Kim Tae Hoon , Hampton John G , Opara Linus U , Hardacre Allan K , Mackay Bruce R 
Published: October 2002

AbstractThe effects of maize (Zea mays L) grain hardness, morphological factors (grain size and shape), drying rate and the development of stress cracking over time were investigated for four hybrids (Hmv565 − 3 × E1386, CF06, CF05 and Furio). The re‐parametrised Morgan–Mercer–Flodin (MMF) model successfully predicted the rate (κ) and maximum value (α) of percentage checked stress cracking (checking) in various sizes, shapes and hardnesses of grains with time after drying. The maximum percentage checking (α) was significantly correlated with grain length (r = −0.707), thickness (r = 0.620), roundness (r = 0.703) and the shortest diffusion pathway (r = 0.627). The rate (κ) of percentage checking with time after drying was significantly correlated with grain bulk density (r = −0.564), hardness ratio (r = −0.611) and drying rate (r = 0.551) and, to a lesser extent, with grain size parameters including hundred‐grain weight, grain length and width. Removing small and round grains could reduce checked stress cracking by up to 50% in some dent maize hybrids.© 2002 Society of Chemical Industry
Quantitative analysis of the volatile aroma components of pepino fruit by purge‐and‐trap and gas chromatography
Authors: Ruiz‐Beviá Francisco , Font Alicia , García Angela N , Blasco Pilar , Ruiz Juan J 
Published: October 2002

AbstractA system specifically designed for the analysis of volatile organic compounds in water, called the purge‐and‐trap sample concentrator, has been set up to quantify the volatile aroma constituents of fruits. The technique shows some advantages over other conventional and new methods. The quantification of the major volatile compounds (3‐methyl‐2‐buten‐1‐ol, 3‐methyl‐3‐buten‐1‐ol and their acetates) of different pepino fruit samples has been performed using the purge‐and‐trap method. Relationships between the volatile content and the characteristics of fruits have been established.© 2002 Society of Chemical Industry
Dynamic rheology of structural development in starch/decolourised hsian‐tsao leaf gum composite systems
Authors: Lai Lih‐Shiuh , Liao Chih‐Lun 
Published: October 2002

AbstractThe gelling process of decolourised hsian‐tsao leaf gum (dHG)/starch mixtures was monitored as a function of starch/gum ratio and starch type using a dynamic rheometer. It was found that the gelling process followed first‐order kinetics. At starch/gum ratios of 5:1, 4:2 and 3:3, dHG interacted with starch synergistically, resulting in a marked increase in storage modulus (G′). Both the gelling reaction rate constant and plateau G′ value as a function of starch/dHG ratio showed a maximum at a certain starch/gum ratio. These results indicated that a suitable starch/dHG ratio could facilitate the formation of a three‐dimensional network structure and the conversion of chains in the sol fraction into a gel. The maximum G′ value reached depended on the unique chemistry of each starch. Mixed systems with tapioca starch generally showed lower plateau G′ values than mixed systems with wheat or corn starch, possibly owing to the lower amylose content of tapioca starch.© 2002 Society of Chemical Industry
Seasonal climate effects on root colour and compounds of red radish
Authors: Schreiner M , Huyskens‐Keil S , Peters P , Schonhof I , Krumbein A , Widell S 
Published: October 2002

Abstract‘Nevadar’ radishes were grown throughout the year. Climate parameters (mean temperature, mean irradiation) and quality characteristics of radishes fulfilling consumer quality requirements, such as root colour, glucosinolates, monosaccharides and pectic substances, were determined. The quality characteristics strongly differed depending on the seasonal climate conditions. The seasonal dependence ranged from a slight climate influence (alkenyl glucosinolates r2 = 0.23), over a moderate climate effect (indolyl glucosinolates r2 = 0.40, glucose r2 = 0.50) up to a strongly distinctive climate influence (hue angle r2 = 0.77, chroma r2 = 0.72, fructose r2 = 0.81, pectic substances r2 = 0.99). Therefore, according to consumer‐oriented quality production of radish, the temperature and irradiation influence should be taken into account in the production process. Recommendations for quality production of radish will be the selection of bright red cultivars marked by a high photosynthetic capacity (yield > 0.80 mV) at relatively low mean irradiation intensities (50–100 µmol  m2 s−1) and lower mean temperatures (11–13 °C). Thus sufficient photochemical energy can be provided for the synthesis of quality‐determining compounds. For the production of bioactive radishes showing particularly relatively high contents of indolyl glucosinolates, cultivation should be carried out in spring and autumn. In summer cultivation, consumer preferences in taste can particularly be satisfied with the desired contents of alkenyl glucosinolates and monosaccharides.© 2002 Society of Chemical Industry
Micellar medium effects on the hydrolysis of phenyl chloroformate in ionic, zwitterionic, nonionic, and mixed micellar solutions
Authors: Muñoz María , Rodríguez Amalia , Del Mar Graciani María , Luisa Moyá María 
Published: October 2002

AbstractThe spontaneous hydrolysis of phenyl chloroformate was studied in various anionic, nonionic, zwitterionic, and cationic aqueous micellar solutions, as well as in mixed anionic–nonionic micellar solutions. In all cases, an increase in the surfactant concentration results in a decrease in the reaction rate and micellar effects were quantitatively explained in terms of distribution of the substrate between water and micelles and the first‐order rate constants in the aqueous and micellar pseudophases. A comparison of the kinetic data in nonionic micellar solutions to those in anionic and zwiterionic micellar solutions makes clear that charge effects of micelles is not the only factor responsible for the variations in the reaction rate. Depletion of water in the interfacial region and its different characteristics as compared to bulk water, the presence of high ionic concentration in the Stern layer of ionic micelles, and differences in the stabilization of the initial state and the transition state by hydrophobic interactions with surfactant tails can also influence reactivity. The different deceleration of the reaction observed in the various micellar solutions studied was discussed by considering these factors. Synergism in mixed‐micellar solutions is shown through the kinetic data obtained in these media. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 445–451, 2002
Kinetics of reactions of OBrO with NO, O3, OClO, and ClO at 240–350 K
Authors: Li Zhuangjie , Jeong Gill‐Ran , Person Eric 
Published: October 2002

AbstractKinetics for the reactions of OBrO with NO, O3, OClO, and ClO at 240–350 K were investigated using the technique of discharge flow coupled with mass spectrometry. The Arrhenius expression for the OBrO reaction with NO was determined to be k1 = (2.37 ± 0.96) × 10−13 exp[(607 ± 63)/T] cm3 molecule−1 s−1. The reactions of OBrO with O3, OClO, and ClO are slow chemical processes at 240–350 K. Upper limit rate constants for the OBrO reactions with O3, OClO, and ClO at 240–350 K were estimated to be k2 < 5.0 × 10−15 cm3 molecule−1 s−1, k3 < 6.0 × 10−14 cm3 molecule−1 s−1, and k4 < 1.5 × 10−13 cm3 molecule−1 s−1, respectively. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 430–437, 2002
Permanganate oxidation of unsaturated alcohols in alkaline media
Authors: Jáky Miklós , Simon‐Trompler Edit 
Published: October 2002

AbstractA study was made on permanganate oxidation of olefinic and acetylenic alcohols in aqueous alkali media. Deprotonation constants of alcohols can be calculated from the kinetic data. The rate constant of alkoxide group oxidation exceeded that of the unsaturated bond. For oxidation of the alcoholic group a mechanism based on hydride ion transfer is proposed. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 561–567, 2002