bluuebunny/crossref_metadata_2025_split huggingface dataset:
Myosins from red and white bovine muscles: Differences measured by turbidimetric, calorimetric and rheological techniques
Authors: Egelandsdal Bjorg , Martinsen Berit K , Fretheim Kristen , Pettersen Marianne , Harbitz Ole 
Published: November 2006

AbstractThe aim of this study was to elucidate the functional performance of the most abundant protein component in meat, ie myosin, which is recognised as important for binding in meat products. As several genetic variants of skeletal myosin exist, myosins from two bovine muscles of different fibre type composition, M masseter and M cutaneus trunci were compared with respect to filament forming properties and denaturation characteristics. The principal methods used were turbidimetric measurements, which were used to monitor filament formation, calorimetry and rheology. The myosin systems were examined at two different salt levels (0.2 and 0.6 M NaCl) and at pH 5.5–7.0. The method of preparing myosin suspensions/solutions was also examined. Differences in the filament‐forming process for the two myosins were detected. Measurements of turbidity revealed that at conditions of low pH and low ionic strength white myosin had a higher ultimate turbidity compared with red myosin. Early in the transition from low to high turbidity, red myosin had a higher turbidity than white myosin corresponding to reduced solubility. The turbidity increased with time of storing the myosin suspensions/solutions. This change was attributed to formation of filaments and further association of filaments. White myosin had a smaller apparent enthalpy of denaturation than red myosin. The calorimetric measurements recorded in 0.2 M NaCl suggested that the head and the rod of white myosin were less stable than the corresponding parts of red myosin. However, exceptions to this rule were found at pH 6.0. In 0.6 M NaCl the identification of the transitions for red myosin was more difficult. The method of preparing myosin suspensions affected calorimetric and rheological measurements. In 0.6 M NaCl and pH 6.0 calorimetric thermograms of both myosins were affected by the preparation method. At pH 5.5 this change was interpreted as caused by denaturation promoted by the dilution/rapid titration technique compared with dialysing the systems to pH 5.5 from pH 7. Differences in the filaments formed might, however, also contribute to the variations seen in the calorimetric ther‐mograms. The gelling properties of white myosin were most sensitive to the preparation method used. Systems prepared by dialysis gave stronger heat‐induced gels than those prepared by ‘dilution’. White myosin always produced stronger gels than red myosin independent of the preparation technique. The rheological properties (at 80°C) of red myosin were less affected by the preparation method than were those of white myosin. At lower temperatures, however, there was more variation in the shapes of the rheological thermograms (Ǵ versus temperature) for red myosin than in the corresponding thermograms of white myosin.
Potentiometric titration studies on xanthan solutions
Authors: Young San‐Land , Martino Miriam , Kienzle‐Sterzer Carlos , Torres J Antonio 
Published: November 2006

AbstractThe potentiometric behavior of xanthan solutions was analyzed as a function of ionic strength, polymer concentration and temperature. For a given value of the polymer dissociation constant, α, pKawas linearly correlated withCs1/3(salt concentration). At polymer concentrations below 7.5 g liter‐1, pKawas a function of polymer concentration. However, when the polymer concentration was higher than this value, pKawas independent of polymer concentration. Potentiometric titration confirmed the significance of the hydrogen bond and the carboxylate group on the secondary structure of xanthan which suggested that the ordered xanthan conformation is stabilized mainly by hydrogen bonds. These can be disrupted by increasing the electrostatic potential of the molecule or by increasing the solution temperature. Neither the ionic strength nor the polymer concentration affected the secondary structure of xanthan at 25°C. However, ionic strength should reduce the repulsive force between charged groups in xanthan; this would explain the salt stabilization of the secondary structure observed at the higher test temperatures (35–70°C).
The use of continuous‐flow electrophoresis to remove pectin in the purification of the minor pectinesterases in lemon fruits (citrus limon)
Authors: Macdonald Helen M , Evans Roger , Spencer Wendy J 
Published: November 2006

AbstractContinuous‐flow electrophoresis was used to separate pectin and coloured substances from extracts of lemon pectinesterase. Two minor lemon pectinesterases were subsequently separated from two major pectinesterases, using chromatography on Sephadex G‐75 and CM‐Sephadex C‐50. One minor pectinesterase was stable at low pH, showed the same initial pectinesterase activity at 88°C as at 25°C, and was active at 85°C for 9 min. This enzyme destabilised the cloud of single‐strength lemon juice. It is suggested that the minor pectinesterases might not be true isozymes, but could arise from association of a major enzyme with pectin.
Transformations of (14C‐lignin) cell walls of wheat by rumen microorganisms
Authors: Mosoni Pascale , Besle Jean‐Michel , Toillon Sylvie , Jouany Jean‐Pierre 
Published: November 2006

AbstractThe lower halves of apical internodes of wheat harvested at the flowering stage were labelled with [U‐14C] phenylalanine (phe) or with [O14CH3] sinapic acid (sin). Cell wall residues (CWR) and saponified residues (SR) were incubated in a fermenter simulating the rumen for 7 days with rumen fluid or without microorganisms (controls). PheCWR was labelled in all lignin units (measured as aldehydes from nitrobenzene oxidation), in phenolic acids and slightly in proteins. Labelling of pheSR was more lignin‐specific. SinCWR and sinSR were specifically labelled in syringyl units of lignin. The fermentation of CWR resulted in phenylpropane‐derived unit losses in the following decreasing order: ferulic acid>p‐coumaric acid>syringaldehyde>vanillin>p‐hydroxybenzaldehyde. If allowance is made for slight losses in controls, 61, 52, 61 and 63% of the phenylpropanes of pheCWR, sinCWR, pheSR and sinSR, respectively, were transformed into an acid‐precipitable fraction, an acid‐soluble fraction and 14CO2. The comparison of pheCWR and sinCWR degradation showed that syringyl units were solubilised into acid‐precipitable molecules to a greater extent than the other lignin units; demethylation of the syringyl units of lignins was also evident from the different productions of 14CO2. Alkali‐resistant lignins of SR were mainly transformed into acid‐precipitable molecules and were weakly degraded. Lignin solubilisation and degradation seem to be governed by different mechanisms which depend on both cell wall structure and rumen microflora.
A comparison of enzyme preparations to liberate folic acid for the microbiological assay of feed ingredients
Authors: Ryu Kyeong‐Seon , Eitenmiller Ronald R , Pesti Gene M 
Published: November 2006

AbstractMicrobiological assays were conducted to determine the level of total folate in feed ingredients using Lactobacillus casei (ATCC 7469). Fifty‐seven samples of feedstuffs were collected from several locations in the southeastern USA by a major broiler producer. Folic acid contents of samples pretreated before assay with three enzymes (conjugase, α‐amylase, a mixture of protease (Pronase®, were 22±86 ± 1.99 (μg per 100 g ± SD) for corn (N = 14), 22±01 + 1.18 for fish meal (N = 7), 29.34 ± 0.55 for milo (N = 4), 25.80 ± 6.93 for bakery meal (N = 5), 56.76 ± 4.97 for meat and bone meal (N = 4), 85.14 ± 2.56 for wheat middlings (N = 5), and 193.97 ± 11.19 for soybean meal (N = 18). Predigestion with conjugase, α‐amylase and Pronase® liberated folic acid and increased values by 22.3% compared to conjugase predigestion alone (P≤0.05). This study shows that the traditional conjugase pretreatment does not completely free folate from complex feed ingredients for microbiological analysis.
Aflatoxin B1 contamination of shrimp feeds and its effect on growth and hepatopancreas of pre‐adult Penaeus monodon
Authors: Bautista Myrna N , Lavilla‐Pitogo Celia R , Subosa Precilla F , Begino Edna T 
Published: November 2006

AbstractA survey of aflatoxin B1 (AFLB1) levels in commonly used commercial shrimp finisher feeds in the Philippines showed a various range of values from not detected to 120 μg kg−1 using high‐performance thin‐layer chromatography. Six experimental diets were prepared to contain various levels of AFLB1 based on survey results to determine the effects of such contamination in pre‐adult shrimp Penaeus monodon (17.5 ± 0.6 g). Results showed that shrimps fed diets containing AFLB1 greater than or equal to 73.8 μg kg−1 gave comparatively poor growth rate and higher susceptibility to shell diseases. No AFLB1 residues were detected in sampled whole shrimp tissues after 62 days of exposure to AFLB1 containing diets indicating a low potential for transmission of the toxin from edible shrimp tissues to consumers. Histopathological alterations in the hepatopancreas of shrimp chronically exposed to AFLB, were observed in all samples. The degree of alterations correlated with the level of AFLB1. Based on growth performance, pre‐adult shrimps can tolerate AFLB1 levels of up to 52.3 μg kg−1 in the feeds although histopathological changes were already evident in the tissues of shrimps given diets with 26.5 μg kg−1 AFLB1.
Effects of some purified alfalfa (Medic ago sativa) saponins on transmural potential difference in mammalian small intestine
Authors: Oleszek W , Nowacka J , Gee J M , Wortley G M , Johnson I T 
Published: November 2006

AbstractThe effect of a range of structurally divergent alfalfa saponins on the potential difference (PD) across the rat small intestine has been examined in vitro Typically, there was an immediate reduction in PD, although there was considerable variation in response to particular compounds. Among the glycosides of medicagenic acid, bisdesmosides containing four sugar moieties had activities equal to the monodesmoside and to medicagenic acid itself. The exception was 3Glc, 28Glc‐medicagenic acid, which did not affect the membrane potential. Zanhic acid glycosides reduced the PD to a much greater extent than medicagenic acid derived compounds. The tridesmoside of zanhic acid was the most active compound tested. This compound is however not precipitated by cholesterol and hence would not have been present in the ‘biologically active’ fractions used in previous studies. The present data show that both the lipophilic aglyconc portion of saponins, and the sugar composition can influence the ability of these compounds to depolarized the intestinal mucosa. The observations are discussed in the light of anti nutritional properties of alfalfa saponins when fed to monogastric animals.
Evaluation of the seeds of selected lines of three Lathyrus spp for β‐N‐oxalylamino‐L‐ alanine (BOAA), tannins, trypsin inhibitor activity and certain in‐vitro characteristics
Authors: Aletor Valentine A , El‐Moneim Ali Abd , Goodchild Anthony V 
Published: November 2006

AbstractSixty eight lines comprising 36 Lathyrus sativus, 16 L cicera and 16 of L ochrus were analysed for crude protein (CP), the neurotoxin β‐N‐oxalylamino‐ L‐alanine (BOAA), protein precipitable tannin (PPT), catechin equivalents (CE), and trypsin inhibitor activity (TIA). Randomly chosen lines from each of the species were also evaluated for other chemical and in‐vitro characteristics including neutral detergent fibre (NDF), acid detergent fibre (ADF), in‐vitro dry matter and in‐vitro organic matter digestibilities (IVDMD, IVOMD), respectively.The species with the lowest and highest CP were L cicera(295.39 ± 18.69 g kg−1 DM) and L sativus(324.99 ± 13.40 g kg−1 DM), respectively. BOAA concentration, also, was least in L cicera (1.26 ± 0.18 g kg−1 DM) and highest in L sativus(5.63 ± 0.43 g kg−1 DM). There were higher intraspecies variations in BOAA levels among L sativus and L cicera than in L ochus genotypes. On average, BOAA levels in L ochrus and L sativus were about four to five times higher than those in L cicera. The PPT level in L sativus(4.54 ± 0.31 g kg−1 DM) was similar to that in the other species. However, there were some lines without detectable PPT in all the species. CE, which detects simple flavonoids as well as condensed tannins, was no more than 6.10 g kg−1DM in any accession, except in L ochrus in which CE ranged from 14.07 g kg−1 to 28.50 g kg−1 DM. There were high variabilities between and within species in CE values as shown by the high coefficients of variation. Mean TIA in all the L sativus lines (18.16 ± 2.38 g kg−1 DM) was similar to that in L ochrus and about twice the levels in L cicera. The coefficients of variation ranged from 10.93% in L ochrus to 17.13% in L sativus. The ash, organic matter and NDF content of the lines did not differ significantly. However, the ADF, IVDMD and IVOMD differed significantly (P < 0.05) between the species. The IVDMD and IVOMD of L cicera (88.55 ± 0.80% and 85.53 ± 0.85%, respectively) were significantly lower (P < 0.05) than in the other species. Seed weight correlated significantly (P < 0.05) with CE and TIA in both L sativus and L ochrus while CP correlated significatly (P < 0.01) with TIA in both L sativus and L cicera with respective r values of 0.70 and −0.75.
Agglomeration of ethyl esters in model spirit solutions and malt whiskies
Authors: Conner John M , Paterson Alistair , Piggott John R 
Published: November 2006

AbstractMedium‐ and long‐chain ethyl esters were found to have a limited solubility when model spirits and malt distillates were diluted to 230 ml ethanol per litre for sensory analysis. At concentrations above this critical level the concentration of esters in solution remained constant, with the excess esters forming agglomerates. The saturated nature of the solution reduced the volatility of other esters, with a proportion of these compounds being partitioned into the agglomerate. The distribution was dependent on the mole fraction of each ester and its activity coefficient. Dissolution of wood extractives caused a number of changes in the solubility parameters of organic compounds; activity coefficients were increased and both the concentration and activity at which agglomeration occurred were decreased. This resulted in lower solution concentrations with increased concentrations in agglomerates. The reductions in free solution concentration could result in lower headspace concentrations, and thus have a direct effect on the flavour of the matured spirit.
Growth, yield and nodule activity of mungbean intercropped with maize and cassava
Authors: Sangakkara Ravi 
Published: November 2006

AbstractA field study evaluated the influence of maize (Zea mays) and cassava (Manihot esculenta) on the growth, yield and nodulation parameters of individual plants of mungbean (Vigna radiata), established as an intercrop. The two systems were managed in a similar manner. Germination, establishment and growth of plants, and yield parameters of mungbean within the maize crop were reduced to a greater extent than that of plants grown with cassava. In addition, in both systems, growth and yields of mungbean plants in close promixity to the non‐legume were suppressed to a greater degree than in plants in the centre rows. In contrast, nodulation and nodule activity of plants in close promixity to maize or cassava was higher than in that of centre rows. The study revealed that shading of mungbean plants in close proximity to maize and cassava does not reduce nodule activity. While competitive relationships between the non‐legume and mungbean could affect the growth and yields of the legume plants in close promixity, the greater utilisation of nitrogen by the non‐legume is suggested to be the causal factor for increased nodule activity.
Rapid determination of chlorophylls in vegetable oils by laser‐based fluorometry
Authors: Tan Y A , Low K S , Chong C L 
Published: November 2006

AbstractThe presence of chlorophylls in vegetable oils is considered undesirable due to their adverse effects on oxidative deterioration, bleachability and hydrogenation. The usual methods for determination of chlorophylls in vegetable oils are absorption spectrophotometry, fluorometry and liquid chromatography using fluorescence detectors. This paper outlines a fluorometric method using a laser as the excitation source. The chlorophylls in crude palm oil, rapeseed oil, soya bean oil and olive oil were determined directly by laser‐based fluorometry using (a) a helium‐neon laser (632‐8 nm, 5 mW) as the excitation source and an optical‐multichannel analyser (OMA) with an intensified diode array as the detector, and (b) a helium‐neon laser and a photomultiplier tube as the detector. The method is especially suitable for the detection of chlorophylls in crude palm oil since no pre‐extraction step is required. The levels of chlorophylls measured in vegetable oils using the laser technique was also compared against values obtained by conventional spectrophotometric methods. The simplicity and rapid quantification of laser based fluorometry suggest that this technique can be readily applied to the detection or a wide variety of fluorescing species in vegetable oils.
Robust sensory evaluation of olive oil by a non‐parametric scoring system
Authors: Van Bruggen P C , Quadt J F A , L'Herminez P C , Vandeginste B G M 
Published: November 2006

AbstractThe quality grade of an olive oil is attributed on the basis of a number of chemical and physical parameters, and, in accordance with EC rules, additionally by the sensory evaluation by a taste panel. Evaluation of the statistics of the method of the Conseil Oléicole International (COI) as reported by Albi and Gutierrez (J Sci Food Agric 54 (1991) 255–267) revealed a number of limitations and weaknesses. An alternative test has therefore been developed. Oils are first tasted by a small panel which decides on acceptance, rejection or further sensory evaluation by a larger panel. The alternative conceptually simpler non‐parametric three‐point scoring system developed removes some drawbacks of the CSIC method. The method was applied to the panel results published by Albi and Gutierrez and the results of both methods were compared.
Occurrence of saponins and sapogenols in Andean crops
Authors: Cuadrado C , Ayet G , Burbano C , Muzquiz M , Camacho L , Cavieres E , Lovon M , Osagie A , Price K R 
Published: November 2006

AbstractSamples of bitter seeds of local ecotypes and cultivars of lupin (Lupin mutabilis), white and yellow ecotypes of quinoa (Chenopodium quinoa Wild) and a local ecotype of amaranth (Amaranthus caudatus) grown in the Peruvian highlands were analysed for total saponin content and sapogenol composition. Sweet cultivars of L albus and L luteus cultivated in mild‐rainy lowlands of Chile were also analysed for comparison. Fast atom bombardment‐mass spectrometry (FAB‐MS) of the saponin extracts and gas chromatography (GC) analysis of the sapogenols after acid hydrolysis of the crude extract‐were used for the identification and quantification of saponins. It was found that L albus and amaranth had undetectable levels of saponins making them attractive for human consumption. The cultivars and ecotypes of L mutabilis contained saponin levels in the range of 229.8–390.5 mg k−1. FAB‐MS showed the presence of soya saponins I and II, whereas GC allowed the identification of soya sapogenols A and B. The same saponin composition was determined in L luteus whose total content was 55.3 mg kg−1. Saponin composition in quinoa seeds comprised oleanolic acid and three other sapogenols identified as hederagenin, phytolaccagenic acid and deoxyphytolaccagenic acid. Oleanolic acid saponins were found to be the main class of saponin in quinoa seeds sampled for this study. The yellow ecotype of quinoa presented a significantly higher content of saponins and of oleanolic acid as compared to white ecotypes. Since only one ecotype of amaranth was analysed, the nutritional significance of no detectable saponin needs further study. It was concluded that the environmental conditions in the Peruvian highlands are determinants of the amount and composition of saponins present in bitter lupine and quinoa.
Effects of explant source, culture medium: Strength and growth regulators on the in‐vitro propagation of three Jamaican yams: (Dioscorea cayenensis, D trifida and d rotundata)
Authors: Mitchell Sylvia A , Asemota Helen N , Ahmad Mohammad H 
Published: November 2006

AbstractExplants of tuber, meristem and vines from three widely cultivated yam species in Jamaica—D cayenensis, D rotundata and D trifida—were examined for their responses to mineral media strength, inorganic ammonium and growth regulator supplements. Tuber pieces (5mm3) showed some positive growth responses but did not produce in‐vitro plantlets on all the media tested. Meristem tips of D trifida grew rapidly on basal media (BM) supplemented with either 0.1 mglitre−1 6‐benzylamino purine (BAP) and 0.01 mg litre−1indole butyric acid or 0.2 mg litre−1 BAP and 1.0 mg litre−1 naphthalene acetic acid (NAA) producing plantlets by 28 weeks. The nodal explants grew rapidly with plantlets obtained from all the cultivars within 4 weeks. Use of young, vigorously growing vines of 8 weeks or less, as explant source, gave low contamination levels (16–25%) in culture when sterilised for 30 min in 200 g litre−1 NaOCl in the case of D trifida and 300 g litre−1 NaOCl in the case of D cayenesis prior to culturing. Initiation of growth was optimal when explants were taken from monopodial vines grown in October or January and placed on BM supplemented with 0.5 mg litre−1 BAP (BM0.5BAP). Addition of 0.5 mg litre−1 kinetin to the BM or 0.05 mg litre−1 NAA to BM0.5BAP depressed shoot production, while 5.0 mg litre−1 kinetin increased swelling of the nodal region in explants from sympodial shoots and from vines grown in March. The results suggest that nodal segments excised from young, fast growing vines of these species are the best explant source for the purpose of commercial micropropagation.
Effect of lead ions on lipids and antioxidant complex activity of Capsicum annuum L leaves, pericarp and seeds
Authors: Stefanov Kamen L , Seizova Katya A , Pandev Stojan D , Yanishlieva Nedyalka V , Marinova Emma M , Tyankova Lina A , Kuleva Liliana L , Popov Simeon S 
Published: November 2006

AbstractThe composition of the main lipid classes in leaves, pericarp and seeds of pepper (Capsicum annuum L), and the effect of seedlings immersion in lead and sodium acetate nutrient solutions were investigated. Lead ions accumulated mainly in leaves; in pericarp and seeds the concentration of lead was more than 10 times lower. The influence of lead ions on the leaf lipid composition was expressed most in the last stages of plant development. Treatment with lead acetate caused a decrease in the activity of the antioxidative complex in pepper seeds.
Application of flow cytometric DNA measurements in the detection of irradiated onions
Authors: Selvan Emily , Thomas Paul 
Published: November 2006

AbstractNuclei from meristem tissue cells of onion bulbs γ‐irradiated (60–90 Gy) for sprout inhibition and non‐irrádiated control bulbs were isolated periodically during ambient (27–32°C) storage, stained with the fluorochrome 4′,6‐diamidino‐2‐phenylindole and their DNA distribution histograms measured by flow cytometry (FCM). Nuclei from irradiated onions showed a broader DNA distribution profile appearing as a wide (high) coefficient of variation (CV, 4–78%) of the G0/G1 peak as compared with non‐irradiated samples (CV, 2.39%). The DNA index (DI) of the diploid cells in control onions was 1 as against 0.74 in irradiated samples which indicated the presence of G0/G1 cells with abnormal DNA content in the meristem tissue cells of irradiated onions. The results indicate the potential application of quantitating changes in DNA content using FCM by determining CV of the G0/G1 peak as well as DI for differentiating irradiated from non‐irradiated onion bulbs.