bluuebunny/crossref_metadata_2025_split huggingface dataset:
The examination of the headspace volatiles of watercress
Authors: Spence Rose‐Marie M. , Tucknott Owen G. 
Published: October 2006

AbstractWatercress volatiles were collected by adsorption on Porapak Q and solvent elution to obtain samples representative of the intact plant material with minimum glucosnolate degradation. Samples taken after 2 and 7 days trapping as the watercress deteriorated were compared. Several compounds which contribute to the aroma of watercress were identified by gas chromatographic and mass spectrometric analysis and odour evaluation of the gas chromatographic effluent.
Protein extraction from pasture: Effect of crop species, regrowth age and season on the quality of the extracted protein
Authors: Donnelly Paul E. , McDonald Rod M. , Rattray Peter V. 
Published: October 2006

AbstractLeaf protein concentrates (LPC) were prepared from ryegrass (Lolium perenne), white clover (Trifolium repens), lucerne (Medicago sativa cv. Wairau), and from ryegrass/white clover dominant pasture, harvested after a range of regrowth intervals in spring, summer and autumn seasons. Protein quality was measured by rat growth (to give Relative Nutritive Value, RNV) and in‐vivo rat true digestibility. RNV for LPC prepared from all crops was about 50% of that for lactalbumin. Results were highest for lucerne and lowest for ryegrass and ryegrass/white clover. When LPC was supplemented with methionine, RNV improved to 80–90% of that for lactalbumin. Quality was highest and similar for white clover and lucerne and lowest and similar for ryegrass and ryegrass/white clover. The true digestibility of protein was highest for lucerne (82%) and lowest for ryegrass and ryegrass/white clover (70%). These variations may be related to the proportions of cytoplasmic and chloroplastic protein in the juice. There was no effect of season (autumn vs spring) or age of herbage at harvest (4, 6, or 8 weeks regrowth) on the quality of protein. Despite standardised procedures for harvesting, processing, and drying the LPC and for assessing protein quality, undefined factors caused variation in methionine‐supplemented protein quality.
Protein extraction from pasture: The nutritional availability of methionine, cystine and lysine in leaf protein concentrates
Authors: Donnelly Paul E. , Rattray Peter V. 
Published: October 2006

AbstractLeaf protein concentrates (LPC) were prepared from ryegrass (Lolium perenne), white clover (Trifolium repens), mixed ryegrass/white clover and lucerne (Medicago sativa cv. Wairau). Total and nutritionally available levels of methionine and cystine, and nutritionally available levels of lysine were measured. Total and available methionine in LPC averaged 1.94 and 1.60 g 16 g−1 N respectively. The availability of methionine was increased (from 81% to 85%) when the herbage was treated with sodium metabisulphite before pulping. Total and available cystine in LPC averaged 0.96 and 0.26 g 16 g−1 N respectively; availability increased (from 27% to 73%) when herbage was treated with metabisulphite. Of the two sulphur amino acids, cystine undergoes the greatest nutritional damage during processing in the absence of reducing agent. Available lysine averaged 5.29 and 5.61 g 16 g−1 N for control and metabisulphitetreated LPC respectively. Improvements due to metabisulphite were small. Available lysine was higher in LPC from legume herbages (5.9 g 16 g−1 N) than from ryegrass and ryegrass/white clover herbage (5.0 g 16 g−1 N).
Cation exchange capacity and buffering capacity of neutral‐detergent fibres
Authors: McBurney Michael I. , van Soest Peter J. , Chase Larry E. 
Published: October 2006

AbstractDietary fibre buffers the gastrointestinal tract via the inherent buffering capacity of the specific fibre matrix, the quantity of cell wall ingested and the stimulatory effect of cell wall on rumination and/or salivation. The strong bonding of Cu2+ ions for carboxy groups permits their use in estimating the cation exchange capacity (CEC) of both pectinaceous materials and pectin‐free cell wall fractions. The CEC values observed emphasise the different cation exchange capacities of the various plant cell wall components. Cellulose has a relatively low exchange capacity while lignin and Maillard products have a much greater adsorption. Emphasis is placed on the difficulty in utilising gravimetric determinations to interpret physicochemical effects as well as the diversity of plant sources in terms of gastrointestinal buffering.
Polyphenoloxidase from DeChaunac grapes
Authors: Lee C. Y. , Smith N. L. , Pennesi A. P. 
Published: October 2006

AbstractPolyphenoloxidase (PPO) from red grape cultivar, DeChaunac, grown in New York State was isolated and purified 17‐fold by using Phenyl Sepharose CL‐4B column. Disc gel electrophoresis revealed near homogeneity of three isoenzyme bands. The molecular weight of this enzyme ranged from 73 000 to 85 000. The temperature and pH optima of the purified enzyme were 20 °C and 6.0, respectively. Kinetic studies showed that the thermal inactivation of the PPO followed first‐order kinetics, with the activation energy, Ea = 52.39 Kcal mol−1. The substrate specificity showed a high degree of PPO activity toward o‐diphenolic compounds with the highest affinity toward caffeic acid among substrates studied. The apparent Km values for caffeic acid and 4‐methylcatechol as substrates for the Dechaunac PPO were 16 mmol and 25 mmol, respectively. The most potent inhibitors of the PPO were D.L‐dithiothreitol and sodium metasulphite at the concentration level of 0.5 mmol.
Location of sources of variation in forage digestibility
Authors: Moir Kenneth W. 
Published: October 2006

AbstractData from tables of composition of animal feedstuffs in which there were entries for digestibility (digestible dry matter or digestible organic matter) and cell wall were classified into different categories—grass or legume, stage of growth, leaf or stem, and forage species. No conclusions were drawn about legumes, because of insufficient data. After removing the effect of different categories, all the grass species behaved similarly with respect to digested cell walls, In contrast, within‐species variation in digested cell walls was large, as shown by the high residual standard deviation of ± 4.0 in a simple linear regression of in‐vivo digestibility on cell‐wall content. There was a small effect which was due to the lignin content of the cell wall, but the source of most of the variation was not located. While it remains undiscovered, there is a danger that experiments involving forage might merely be testing the effect of treatment on random variation in the digested cell wall.
Production and composition of microbial fat from Rhodotorula glutinis
Authors: Misra Suniti , Ghosh Amitabha , Dutta Jyotirmoy 
Published: October 2006

AbstractThe fatty acid, sterol and hydrocarbon compositions of oil produced by a new strain of Rhodotorula glutinis isolated from soil and grown on molasses, were determined. The major constituent fatty acids were: palmitic (37%) oleic (47%) and linoleic (8%). The major sterols were campesterol (42%) and stigmasterol (27%) and the major hydrocarbons were n‐C23 (37%), iso‐C29 (30%) and n‐C21 (19%). Minor constituents in each class of lipids were also detected and estimated. The oil produced was 54% on a dry weight basis. The fatty acid composition was found to be close to that of palm oil.
Major albumins of Pisum cotyledons
Authors: Schroeder Harmut E. 
Published: October 2006

AbstractThe albumin fraction of the cotyledons of Pisum contains two major polypeptides which together make up 34% (17% each) of the total albumin fraction. Both of these albumins (Mr∼8000 and ∼22000) are cotyledon specific proteins. In many Pisum lines the Mr∼22000 fraction resolves into two components on Na‐dodecylsulphatepolyacrylamide gels. The Mr∼8000 polypeptide was broken down during germination and early seedling growth, indicating that it functions as a storage protein, while the Mr∼22000 polypeptides were degraded relatively slowly. The level of both of these polypeptides was markedly reduced under sulphur deficiency conditions, the Mr∼22000 components being affected to a lesser extent than the Mr∼8000 component. Consistent with this, when [35S]sodium sulphate was injected into the pedicel of control plants during seed development and albumins were isolated at seed maturity, polypeptides of Mr∼8000 and ∼22000 together accounted for a major proportion of the radioactivity in the total albumin fraction. The abundance and relatively high sulphur content of these two albumins could be significant factors in determining the nutritional value of pea seed proteins.
Effect of sitosterol on autoxidation rate and product composition in a model lipid system
Authors: Yanishlieva Nedyalka Vi. , Schiller Helmut 
Published: October 2006

AbstractThe effect of 5% sitosterol on the autoxidation of tristearin at 120°C was investigated. It was found that sitosterol caused a two‐fold increase in the process rate; this effect was unchanged at peroxide concentrations of up to 350 mEq kg−‐1. It was established that introduction of 5% sitosterol considerably increased the concentration of oxidised products in tristearin (from 0.5 to 6.5%) after oxidation at 120°C for 7h. The degree of oxidation of sitosterol in the system was found to be 56%. The structure and composition of oxidised products in the two lipid systems (tristearin, and tristearin+5% sitosterol) were determined. Conclusions were drawn concerning the effect of the lipid medium on the composition and structure of the products of sitosterol autoxidation.
Characterisation of chicken pancreas α‐amylase isozymes and interaction with protein inhibitors from wheat kernel
Authors: Buonocore Vincenzo , Giardina Paola , Parlamenti Roberto , Poerio Elia , Silano Vittorio 
Published: October 2006

AbstractHomogeneous chicken pancreas α‐amylase consists of two main isozymes which have been isolated by ion exchange chromatography; they show similar kinetic behaviour and inhibition patterns by two protein inhibitors from wheat, one monomeric (termed ‘inhibitor 0.28’) and one dimeric (termed ‘inhibitor 0.19’). Inhibitor 0.28 is the wheat kernel amylase inhibitor of Mr 12000 with a gel‐electrophoretic mobility relative to bromophenol blue of 0.28, while inhibitor 0.19 is the wheat kernel inhibitor of Mr 24000 with a relative mobility of 0.19. The chicken pancreatic enzyme was more effectively inhibited by the dimeric (Ki 3.7 nM) than monomeric inhibitor (Ki 570 nM); with both, the inhibition is dependent on pH, temperature and time of preincubation. Gel filtration, difference spectroscopy and kinetic studies have shown that molar combining ratios for amylase‐inhibitor 0.19 and amylase‐inhibitor 0.28 complexes are 1:1 and 1:2 respectively. Difference spectra of both amylase‐inhibitor complexes indicate that structurally related tryptophanyl side chains are involved in the binding of the two inhibitors to the enzyme. In conclusion, the interaction between chicken pancreas α‐amylase and inhibitor 0.19 or 0.28 fits the model proposed for amylase‐wheat inhibitor interactions.
Volatile components of cured and uncured pork: The role of nitrite and the formation of nitrogen compounds
Authors: Mottram Donald S. , Croft Susan E. , Patterson Ronald L. S. 
Published: October 2006

AbstractA slice‐curing method was used to prepare bacon and nitrite‐free salt pork. Headspace volatiles from the cooked products, and from cooked untreated pork, were entrained on Tenax GC and analysed by combined gas chromatography‐mass spectrometry. Aliphatic alcohols and aldehydes dominated the volatiles of all samples; small amounts of ketones, alkybenzenes, pyrazines, pyridines, thiazoles and furans were also present. Untreated pork and salt pork contained essentially the same volatiles, while the bacon showed a number of qualitative differences: several unsaturated and aromatic aldehydes were only present in nitrite free samples and benzonitrile, phenylacetonitrile and four alkyl nitrates were found only in bacon volatiles. The possible origins of these nitrogen‐compounds from the reaction of nitrite with flavour precursors are discussed.
Trimethylamine taint in eggs: The occurrence of the causative metabolic defect in commercial hybrids and pure breeds in relation to shell colour
Authors: Butler Edward J. , Pearson Arthur W. , Greenwood Neil M. 
Published: October 2006

AbstractSix commercial foundation flocks (Rhode Island Red, New Hampshire Red and White Leghorn hybrids) and four pure breeds (Rhode Island Red, Light Sussex, White and Brown Leghorns) were included in a survey which was carried out to facilitate the elimination of the tainting defect from commercial stock by selective breeding. The defect results from an inherited inability to synthesise adequate amounts of trimethylamine (TMA) oxidase, and was detected by estimating the activity of the enzyme in the livers of young chickens, or by measuring the amount of [14C]‐TMA oxide in the plasma after the injection of [14C]‐TMA. It was present in two of the brown‐egg breeds (Rhode Island Red and Light Sussex) and in one of the white‐egg breeds (Brown Leghorn), and therefore was not associated with shell colour. There was no significant correlation between depth of shell colour and TMA oxidase activity in a commercial Rhode Island Red flock.
Natural plant enzyme inhibitors: A comparative study of the action of legume inhibitors on human and bovine pancreatic proteinases
Authors: Prabhu K. Sudhakar , Saldanha Kenneth , Pattabiraman Thillaisthanam N. 
Published: October 2006

AbstractInhibition of total proteolytic (caseinolytic), tryptic (by hydrolysis of benzoyl arginine p‐nitroanilide) and chymotrypic (by hydrolysis of acetyl tryosine ethyl ester) activities by ten species of legume seeds on human and bovine pancreatic proteases were compared. Sword bean extract had a negligible action on human enzymes, but could completely inhibit bovine trypsin and chymotrypsin. Indian red wood seed extract was more active on human than on bovine enzymes, whereas soya bean, field bean, kidney bean and bengal gram were more active on the bovine counterparts. While acacia seed extracts displayed more pronounced action on human trypsins and chymotrypsins, it was more effective in inhibiting the total proteolytic activity of the bovine system. Cowpea and red gram were more effective in inhibiting the human chymotrypsins. The relative contributions of trypsins plus chymotrypsins, elastases and carboxypeptidases to the total proteolytic activity of human pancreatic preparation were found to be 50, 25 and 25% whereas in the bovine system the values were 75, 20 and 5%.
Suitability of four blackcurrant cultivars for industrial syrup production
Authors: Blom Hans , Skrede Grete 
Published: October 2006

AbstractThe four blackcurrant cultivars Øjebyn, Ben Nevis, Ben Lomond and Silvergieter have been evaluated with reference to their suitability for syrup production. The examination was based on sensory and physico‐chemical characterisation, and was performed on the berries themselves and the syrup. The results show that Øjebyn is less suitable for syrup production, while Ben Nevis and Ben Lomond differ insignificantly in most qualities from the reference cultivar, Silvergieter. Criteria for the evaluation of cultivars for industrial suitability are discussed.
Volatile flavour components of Allium grayi regal
Authors: Hashimoto Seiji , Miyazawa Mistuo , Kameoka Hiromu 
Published: October 2006

AbstractThe volatile flavour components of Allium grayi Regal have been investigated by a combination of chromatographic and spectroscopic methods. Among the more than 90 component peaks observed by capillary gas chromatography of the oil obtained by ether extraction of the steam distillate, 47 compounds were positively identified. They included 11 sulphur compounds, 5 alcohols, 7 aldehydes, 3 ketones, 2 furanones and 19 miscellaneous compounds.
Quantitative analysis of styrene monomer in foods. A limited East Australian Survey
Authors: Flanjak Johann , Sharrad Julian 
Published: October 2006

AbstractThe levels of styrene monomer in foods packaged in polystyrene containers were determined by a headspace gas chromatography (g.c.) method and two reversed phase high‐performance liquid chromatography (h.p.l.c.) methods. A total of 146 samples were analysed from Victoria and New South Wales which included yoghurt, cream, cheese, dessert, ice cream, egg white, onion dip and margarine. The highest level of styrene found was 0.1 mg kg−1 in yoghurt. About 85% of all yoghurt samples were found to have values less than 0.05 mg kg−1. The lowest values of styrene obtained were for margarine samples, of which more than 90% contained less than 0.010 mg kg−1. The estimated limits of detection of the h.p.l.c. methods for all products except margarine were 0.005 mg kg−1. The h.p.l.c. detection limit for margarine and the g.c. method for yoghurt were estimated to be 0.01 mg kg−1.
Glycoalkaloid content of potatoes and potato products sold in the UK
Authors: Davies Anthony M. C. , Blincow Philip J. 
Published: October 2006

AbstractPotatoes and potato products were collected from six areas of the UK. Composite samples of potatoes, determined by variety, collection area and collection date, and composite samples of similar potato products were prepared. The glycoalkaloid content of the samples was determined and only two samples out of 133 analysed exceeded the recommended maximum level of 20 mg 100 g−1 fresh weight. The mean values were: main crop 10.4mg 100g−1, UK earlies 11.3mg 100g−1 and imported earlies 12.3 mg 100 g−1 Potato products, when calculated on an equivalent fresh weight basis, all contained less than 10mg 100g−1.
Effect of heating at deep‐fat frying temperature on the sterol content of soya bean oil
Authors: Ghavami Mehrdad , Morton Ian D. 
Published: October 2006

AbstractPreliminary studies by gas chromatography of phytosterols naturally present and added to soya bean oil, indicated that large quantities of these sterols were lost when soya bean oil was exposed to high temperature for a long period. The products which might have been produced as the result of sterol oxidation were not found as members of the nonsaponifiable fraction when this fraction was examined by thin layer and gas chromatography.
Selenium speciation in the soil solution and its relevance to plant uptake
Authors: Van Dorst Sheila H. , Peterson Peter J. 
Published: October 2006

AbstractThe relationship between soil and plant selenium has been investigated using two 75SeO3 spiked silt loam soils from the Hoosfield series with long‐term equilibration pH values of 4.5 and 7. Lolium perenne plants were grown in the soils over a 15‐week period, and seven harvests were made. Plant samples and soil solutions were assayed for radioactivity, and selenium compounds found in the soil solutions separated by high voltage paper electrophoresis. Throughout the 15‐week experimental period selenium speciation was observed to change in soil solution. Samples collected at day 2 from pH 4.5 soil revealed that selenate accounted for 71% and selenite 8% of the soluble selenium compounds present, whereas for the pH 7 soil the relative percentages were 51 and 23% respectively. After 105 days selenate accounted for 22% and selenite 20% at pH 4.5, and 12 and 22% respectively at pH 7. The occurrence of selenoglutathione was noted in the soil solution and its concentration increased significantly with time. Statistically significant correlations (r=0.82) were found between the concentration of selenium in Lolium perenne at harvest and selenate selenium removed from the soil solution.
Optimisation of conditions for the degradation of mimosine in Leucaena leucocephala leaf
Authors: Tangendjaja Budi , Lowry J. Brian , Wills Ron B. H. 
Published: October 2006

AbstractA study was made of the rate of degradation of mimosine to 3‐hydroxy‐4(1H)‐pyridone in harvested leucaena leaf under various conditions. Optimum rates of degradation of an aqueous leucaena slurry were at pH 8.0 and 45°C with virtual total loss of mimosine in 10 min. Heating the intact leaf also reduced the mimosine content with the maximum rate of degradation at 70°C. The results have implications for reducing the toxicity of leucaena used for stock feed.
The lipid composition of the adrenals of non‐pregnant, pregnant and foetal sheep
Authors: Christie W. W. , Noble R. C. 
Published: October 2006

AbstractLipids were isolated from the adrenals of non‐pregnant, pregnant and foetal sheep (ca 30 days pre‐parturition). The lipid content of the adrenals from the pregnant sheep was higher than that of the other groups, and most of this was accounted for by triacylglycerols. Little difference was observed in the fatty acid compositions of the various lipid classes between the pregnant and non‐pregnant animals. All the lipids of the foetal adrenals contained substantial amounts of the 20:3(n–9) fatty acid, which is often associated with essential fatty acid deficiency, but only the cholesterol ester fraction contained a higher level of polyunsaturated fatty acids than was present in the adult groups. The adrenals of the pregnant sheep contained significant levels of glycerolether diesters and neutral plasmalogens, which were fully characterised, and four unknown components that were tentatively identified as steroidal esters. These components were present at barely detectable levels in the adrenals of non‐pregnant sheep. The triacylglycerols, glycerolether diesters and phosphatidylcholines from each group were, where possible, subjected to stereospecific analysis. The triacylglycerols were distinctive and resembled those of plasma and lymph in structure. The results are discussed in terms of a putative direct role for cholesterol esters in corticosteroidogenesis.
Effects of pH and phosphate status of a silty clay loam on manganese, zinc and copper concentrations in soil fractions and in clover
Authors: El‐Kherbawy Mohamedy I. , Roger Sanders J. 
Published: October 2006

AbstractThe field pH of a silty clay loam soil affected manganese, zinc and copper concentrations in the fraction extracted by DTPA; lower pH soils had higher metal concentrations. The soil pH also affected manganese and zinc but not copper concentrations in the soil solution, and in shoots of clover grown in pots. Metal concentrations in soil fractions were not affected by soil phosphate status, but zinc and copper concentrations in clover shoots were significantly lower when plants were grown on soils of high phosphate status. Manganese and zinc levels in shoots were predicted slightly more accurately by using soil solution data than by using concentrations extracted by DTPA.
The effect of systemic insecticides and nitrogen on oil‐filling in developing seeds of toria (Brassica campestris cv. toria)
Authors: Sukhija Pritam S. , Dhillon Karaj S. , Sanadi Sujay , Munshi Satish K. 
Published: October 2006

AbstractThe systemic insecticides Metasystox and Temik reduced the oil content and increased the free fatty acid and phospholipid contents of the oil of toria seeds at early stages of their development. The oil level was, however, restored when the seeds were sown in soil supplied with nitrogen. At a later developmental stage (30 days after fertilisation), Temik increased, and Metasystox decreased the triacylglycerol content in the oil. Both insecticides increased the relative proportion of erucic acid in the oil, however this increase levelled off in the developing seeds when the toria crop was supplied with nitrogen fertiliser. In in‐vivo studies, Metasystox at 10 μg ml−1 was sufficient to lower the rate of [1‐14C]acetate incorporation into lipids of developing seeds. The effect of Temik on lipid biosynthesis was not as pronounced as that of Metasystox.