bluuebunny/crossref_metadata_2025_split huggingface dataset:
Problems in the determination of FDNB‐available lysine
Authors: Booth V. H. 
Published: November 2006

AbstractMethods that use FDNBAbbreviations used: FDNB, 2,4‐dinitrofluorobenzene;
for the determination of available lysine need a correction for loss. The correction procedure has been studied, especially for vegetable materials.DNP‐L† was adsorbed by residues. To minimise loss of DNP‐L, hydrolysates were filtered hot and residues washed thoroughly. Hydrolysis of dinitrophenylated protein was incomplete after 16 h reflux in 5.8 M‐HCl, the yield of DNP‐L being improved by a second hydrolysis of residues. The effect of obtaining higher values after hydrolysis in a large volume of add (dilute hydrolysis) has been largely eliminated. Although DNP‐L added to dinitrophenylated materials (Carpenter's procedure)1 was partly destroyed during acid digestion, DNP‐L in protein (indigenous DNP‐L) was diminished less. DNP‐protein was therefore tried as recovery agent instead of DNP‐L.A modified Carpenter method is described in the Appendix. The estimated coefficient of variation was 3.8%. Various materials were assayed by this method and by TLMI† (the Silcock methody)2. The two values were closer for animal than for vegetable materials, and for undamaged than for heat, damaged materials. The loss of indigenous DNP‐L during an assay (the criterion being comparison with TLMI) was about half that predicted from the recovery of added DNP‐L, but about equal to that predicted from recovery from DNP‐protein. Less DNP‐L was lost during acid digestion in presence of animal than of vegetable protein.The use of the new, smaller, correction factor is discussed.
The volatile components of Scotch whisky
Authors: Williams A. A. , Tucknott O. G. 
Published: November 2006

AbstractCoupled gas chromatographic‐mass spectroscopic analysis of the volatile components of whisky, obtained by vacuum distillation and solvent extraction, has led to the identification of 2 hydrocarbons, 10 alcohols, 2 acids, 18 esters, 8 carbonyls and 4 acetals, a further 16 components being tentatively reported.
Changes in the composition of ovomucin during liquefaction of thick egg white
Authors: Robinson D. S. , Monsey J. B. 
Published: November 2006

AbstractPreparations of purified ovomucin complex have been obtained from samples of thick egg white which were liquefied during incubation at 37 °C under sterile conditions. Chemical analyses of the ovomucin complex and analytical ultra‐centrifugation of fully reduced derivatives of the ovomucin complex obtained from thick egg white thinned by incubation at 37 °C have shown that these preparations, unlike those obtained from “fresh” thick egg white, contained only small quantities of β‐ovomucin. It is postulated that β‐ovomucin is converted to a more soluble form during the natural thinning of thick egg white at 37 °C.
The comparative metabolism of pyrantel in five species
Authors: Faulkner J. K. , Figdor S. K. , Monro A. M. , Von Wittenau M. Schach , Stopher D. A. , Wood B. A. 
Published: November 2006

AbstractThe absorption, distribution and excretion of [14C]‐ and [3H]pyrantel tartrate after oral administration to the sheep, ox, pig, dog and rat have been studied. Urinary excretion of radioactivity was greatest in the pig and the dog, accounting for approx. 34 and 40% of the dose respectively. Absorption was also good in the rat as indicated by some excretion of radioactivity in the bile. In the sheep and the ox approximately 60% of dose was excreted unchanged in the faeces, this probably representing unabsorbed rather than biliary‐excreted material. The highest tissue levels of radioactivity were found in the liver. Apart from the excretion of unchanged pyrantel in the faeces of the sheep and the ox, pyrantel was extensively metabolised in vivo into many metabolites. None of these was identified, but degradation experiments showed that the thiophene ring had been extensively biotransformed and that the tetrahydropyrimidine ring was more resistant to metabolic attack.
Glycosidases and glycanases of wheat flour doughs
Authors: Lee J. W. , Ronalds J. A. 
Published: November 2006

AbstractWheat flour contains hydrolytic enzymes capable of reducing dramatically the viscosity of the aqueous solution obtained by high‐speed centrifugation of dough. Indirect evidence suggests this reduction in viscosity is largely due to the hydrolysis of glycosidic linkages in the non‐starch polysaccharides. Soluble proteins and starch contribute less to the viscosity of this dough liquor than do the flour gums. The glycanases in flour relatively rapidly hydrolyse the galactomannan, guaran and carboxymethylcellulose. Flour also contains a wide range of enzymes capable of hydrolysing nitrophenyl α‐ and β‐glucosides, α‐ and β‐galactosides, α‐ and β‐mannosides, α‐arabinoside, β‐fucoside and β‐xyloside. Both the glycanases and the glycosidases show pH optima within the range 4‐6 which covers the range normally encountered in dough.
Chemical composition of pollen with particular reference to cation exchange capacity and uronic acid content
Authors: Knight A. H. , Crooke W. M. , Shepherd H. 
Published: November 2006

AbstractNormal methods of plant analysis proved suitable for the analysis of pollen, despite its extremely durable and unique outer coat of sporopollenin. The cation‐exchange capacity (CEC), uronic acid content (UA) and mineral composition of pollen from 53 Angiosperm and 5 Gymnosperm species were determined. The values found were of the same order as those of leaves, roots and seeds of the same species. Only minor differences in composition and CEC exist between pollen of monocotyledons (monocot) and dicotyledons (dicot), in marked contrast to other plant tissues, where generally the CEC and levels of elements in the dicot plant are higher than in the monocot plant. Relationships connecting CEC with uronic acid, total cations and nitrogen, already established for leaves and roots, also held for pollen although the correlation coefficients were not so high. On the other hand, correlations between CEC and individual cations, especially Ca, in pollen tended to be higher. Pollen of the same species from England and Sweden had similar UA contents (r = 0.91***), suggesting that this constituent and its related CEC value may be characteristic of a species and relatively independent of external soil nutritional factors, as has been found for root CEC.
Biophysical properties of horticultural products as related to loss of moisture during cooling down
Authors: Fockens F. H. , Meffert H. F. Th. 
Published: November 2006

AbstractThe relation between biophysical properties of the skin of horticultural products and the rate of moisture loss under different ambient conditions is explained by a mathematical model. The numerical values of these properties can be determined by a simple experimental method. The effect of different air velocities on the loss of moisture from the products during cooling down is derived mathematically. The theory has been proved by experiments.
Bread staling. IV. Electrical properties of the crumb during staling
Authors: Kay M. , Willhoft E. M. A. 
Published: November 2006

AbstractA new technique for studying the staling of bread is described based on conductance and capacitance measurements on the isolated centre‐crumb. It is proposed that the observed changes (up to 17%) in the electrical properties are due to retrogradation of the starch as well as the changes undergone by the transforming protein. Moisture redistribution is thought not to play a significant role during staling of the crumb at temperatures of less than about 10 °C. At 36 °C the first‐order rate‐constant for the protein transformation was estimated to be 0.7 day−1 and 0.3 day−1 for the rate constant for retrogradation of the starch fraction of the crumb. At 0 °C, the protein transformation was insignificant and the rate constant for the starch change was 1.03 day−1. The thickness of the gluten membrane surrounding the starch granules in bread was approximated to be less than 1 μm.
A semi‐micro method for the determination of lignin and its use in predicting the digestibility of forage crops
Authors: Morrison I. M. 
Published: November 2006

AbstractThe lignin content of dried grasses can be measured, after prior removal of interfering phenolic materials, by dissolving the residue in 25% acetyl bromide in acetic acid and determining the absorption at 280 nm. The absorption values can also be used to predict the nutritive value of dried grasses, hays and silages.
Physical and chemical changes in developing strawberry fruits
Authors: Woodward J. R. 
Published: November 2006

AbstractStrawberry fruits of thevariety Red Gauntlet were harvested at 7 day intervals after petal fall. Changes in fruit weight, percentages survival on the plant, chlorophyll: carotenoid and anthocyanin, titratable acid, pH of extracts and sugar content were measured. Also changes in soluble and total pectic polysaccharides in alcoholinsoluble residues of harvested fruits were followed during development.Fruit growth was not exponential and in later stages of growth the falling survival rate was correlated to fruit softening. Net synthesis of chlorophyll and carotenoid pigments took place up to 28 days and anthocyanin synthesis commenced 28 to 35 days after petal fall. The sugar content of berries increased with time and titratable acid concentrations increased slightly during development, falling in ripening fruits.The specific viscosity of soluble pectic polysaccharides fell from 28 days after petal fall. There was net synthesis of polyuronide but not neutral polysaccharide during the development of fruits and the amount of insoluble pectic polysaccharide became small and relatively constant compared with the amount of soluble polysaccharide by 21 days after petal fall. Fruits undergoing senescence lost almost all their insoluble pectic polysaccharides.The developmental processes taking place in growing fruits, especially with respect to changes in cell wall structure, and the relevance of results to fruit storage are discussed.
Chemical composition of Candida utilis and the biological quality of the yeast protein
Authors: Yáñez E. , Ballester Digna , Fernández Natividad , Gattás Vivien , Monckeberg F. 
Published: November 2006

AbstractThe chemical composition (moisture, ash, protein and non‐protein N, amino acids, ether extract, crude fibre, Ca, P, Fe) and biological quality (protein efficiency ratio and available lysine) were investigated in two batches of Candida utilis (Torula yeast). The samples (S1 and S2) were collected from a local factory. S2 was sterilised before drying. Protein, mineral and B‐complex vitamin contents were comparatively high. Amino‐acid analysis showed a high content of lysine and threonine, but a deficiency in sulphur amino acids. The biological quality measured as the protein efficiency ratio (p.e.r.) and available lysine gave values of 1.80 ± 0.05 and 6.6 g/100g of crude protein, respectively, in S1. These are higher than values reported in the literature. Sterilisation (S2) and storage for 1 year (S1(a)) significantly reduced the biological quality of the protein (p.e.r. 1.15 ± 0.12 and 1.34 ± 0.07, respectively). Supplementation of C. utilis with 0.3% DL‐methionine increased the p.e.r. value to 2.77 ± 0.03, close to that of casein. C. utilis appears to be a valuable material for human diets because of the high content and satisfactory quality of its protein and other nutrients.
Superficial scald, a functional disorder of stored apples VIII. Volatile products from the autoxidation of α‐farnesen
Authors: Anet E. F. L. J. 
Published: November 2006

AbstractThe main volatile product during the early stages of the autoxidation of α‐farnesene is 6‐methyl‐5‐hepten‐2‐one. Evidence that other unsaturated volatile ketones are also formed was obtained by catalytic reduction of the reaction mixture, when their more stable saturated derivatives were isolated. These ketones may arise by fragmentation of an α‐farnesene derivative at the central tertiary carbon atom in each of three possible ways.
A modified hypothesis for the structure and rheology of glutelins
Authors: Ewart J. A. D. 
Published: November 2006

AbstractCereal storage proteins, it is suggested, are more tolerant of genetic mutations than other proteins. Evolutionary tendencies may have been towards decreasing the cystine content and increasing the content of amino acids which are easily synthesised, especially those which are rich in nitrogen. The appearance of stress in molecular structure so that an intrachain SS bond is no longer able to close, thus creating interchain linkage, may have led to the origin of the glutelins.It is argued that a viscoelastic dough can be formed only if protein particles, which originate in the form of protein bodies, are able to form a continuous structure whether maintained by covalent bonds or/and secondary forces.The constituent polypeptide chains of glutelins could be joined in a linear or a branched mode. A number of difficulties arise if the branched model is used to explain the properties of dough at the molecular level. In attempting to reconcile fact and theory, it is speculated that polypeptide chains of wheat, rye and barley glutelins form linear concatenations with two disulphide bonds connecting each chain to the next: continuity of structure in their doughs depends on entanglement and interaction by secondary forces. The glutelin molecules of oats and maize are unable to form a continuous network, hence the absence of viscoelasticity from doughs of these cereals. Two reasons are suggested: more probably the molecules are highly cross‐linked in the branched mode and are thus incapable of significant entanglement; or if the molecules were cross‐linked in the linear mode, poor solubility would ensure that protein‐protein contacts in protein bodies were maintained, thus preventing dispersal of the protein and subsequent molecular entanglement. The glutelin molecules of sorghum appear to be too small to create a network by molecular entanglement. The importance of the disulphide interchange reaction is thought to lie in stress relaxation, but not in the creation of a dough structure. It is suggested that SS groups in viscoelastic doughs are sterically protected except when exposed by stress and consequently stress relaxation by SS interchange tends to occur only when it is needed.
Pectinesterase activity of some Iraqi dates at different stages of maturity
Authors: Al‐Jasim H. A. , Al‐Delaimy K. S. 
Published: November 2006

AbstractChanges in the pectinesterase (PE) activity in four Iraqi date varieties at different stages of maturity were followed. The enzyme activity was determined by titration of the carboxylic groups released by the hydrolysis of pectin. The results obtained show that there was an increase in PE activity in these varieties with ripening. The greatest increase occurred during the period when the fruit had passed the yellowish stage and turned soft. This increase in the enzyme activity was then followed by a general decrease as the fruit matured and ripened on the tree. The data also indicate that there was a qualitative difference in the behaviour of these varieties.
Metabolism of citric and malic acids during ripening of tomato fruit
Authors: Davies J. N. , Maw G. A. 
Published: November 2006

AbstractTomato fruit at various stages of ripeness were injected with 14C‐labelled citric and malic acids. The 14CO2 evolved by individual fruit was determined over a 72 h period and the fruit then analysed for the incorporation of 14C into sugars, amino acids and individual non‐volatile organic acids. In mature green tomato fruit citric and malic acids were found to be metabolised to a comparable extent. Appreciable interconversion occurred together with oxidation to CO2 and some labelling of glutamic acid and glutamine. In red fruit, citric acid was not as readily oxidised to CO2 and little conversion to malic acid was observed. On the other hand, malic acid was oxidised to CO2 and converted to citric acid as rapidly as in green fruit with, in addition, appreciable conversion to glutamic acid. These results are discussed in relation to the changes in concentration of the endogenous acids which take place during the ripening of tomato fruit.
Texture of canned potatoes: Use of new objective methods to separate the attributes of mouthfeel and breakdown
Authors: Woodman J. S. , Warren D. S. 
Published: November 2006

AbstractNew methods are described for the objective assessment of mouthfeel (mealiness) using a Kramer Shear Press and for the amount of breakdown by sedimentation of sloughed tissue. Their application to several hundred samples of canned potatoes is reported. These objective methods correlate significantly (P < 0.001) with their subjective counterparts and demonstrate a clearer separation of mouthfeel and breakdown than do subjective methods. Examination of partial correlation coefficients indicates that mouthfeel is more significantly related to the specific gravity of the raw material than is breakdown. In separate experiments, late planting was shown to affect mouthfeel but not breakdown and the addition of calcium chloride to affect breakdown whilst leaving mouthfeel unaltered. Evidence is presented that mouthfeel is a rheological property controlled primarily by solids content; in contrast breakdown is interpreted as a failure of intercellular adhesion.
An investigation on laboratory and field methods of determining the pH of soil suspensions
Authors: Farr E. 
Published: November 2006

AbstractA comparison was made between the pH values of soil samples, measured with a pH meter in the laboratory, and those obtained by using colorimetric indicator solutions in the field. Of the indicators tested, BDH Soil Indicator and bromocresol purple provided the closest overall comparison with laboratory results for soils with pH values from 3.8 to 7.8. Bromocresol green was useful only over a limited range (less than 5.2). Differences in procedure and analysis sometimes produced compensatory errors but the results did not often agree exactly and the magnitude of the discrepancy for any given soil was predictable only within fairly broad limits—the average standard deviation was 0.34 units and there was about a 75% chance of the result determined in the field being within 0.3 units of the result determined in the laboratory.
Lucerne tannins. II. Isolation of tannins from lucerne, their nature and influence on the digestive enzymes in vitro
Authors: Milić Božidar Lj. , Stojanović Srdjan , Vučurević Nada 
Published: November 2006

AbstractTannic substances were isolated from dehydrated lucerne meal and it was found that they contained free gallic acid, gallotannins and flavanols. In the procedure for their isolation, cation and anion exchange resins, Amberlite IR‐120 and Amberlite IR‐45, were used. The isolated tannin was tested as an inhibitor of tryptic digestion of casein, L‐amylolytic digestion of starch and lipase enzymes. In in vitro studies it was found that the isolated tannin has a high inhibitory action on digestive enzymes.
Mercury levels in wheat and other cereals, oilseed and biological samples
Authors: Tkachuk Russell , Kuzina F. D. 
Published: November 2006

AbstractAnalyses of 80 samples of wheat showed a mean mercury content of 8 ng/g, with a range of 4 to 18 ng/g (ng = 10−9 g). Wheat flour contained the same amount of mercury as wheat. Other cereals and oilseeds contained 4 to 29 ng/g of mercury. Levels of mercury varied for other organic materials analysed.The analytical method used is relatively rapid and simple when certain precautions are followed. The method consists of an oxygen‐bomb combustion of samples, reduction of the mercury in the bomb washings to elemental mercury and then analysis of the mercury by cold vapour atomic absorption spectrophotometry. The limit of detection of the method is approximately 1 to 2 ng of mercury/g of sample. The reliability of the method was verified by quantitative recoveries of added organic and inorganic mercury compounds from wheat and barley and by carrying out collaborative tests.
Changes in the carbohydrate constituents of cassava root‐tuber (Manihot utilissima pohl) during growth
Authors: Ketiku A. O. , Oyenuga V. A. 
Published: November 2006

AbstractSucrose formed the bulk of the sugars in cassava root‐tubers, accounting for more than 69% of the total sugars. Other sugars included fructose, glucose and maltose. Maltose was consistently present as the lowest amount. The highest concentration of sugars (5.7%) was attained nine months after planting. Starch accounted for the highest proportion of the carbohydrates. A peak value of 81% was observed eight months after planting. The decrease to 78% at nine months was accompanied by an increase in sugar concentration from 3.5% to 5.7%. The sum of cellulose and hemicellulose constituted the non‐available carbohydrate fraction to non‐ruminants. This was less than 7% of total carbohydrates. Paper chromatography of the neutralised hydrolysate of the extracted hemicellulose revealed the presence of glucose and xylose only. The amylose content of cassava starch varied between 16.2% and 17.4% during growth. This variation was significant at 1% F level. The separated amylose had an iodine affinity of 17.0% while amylopectin had 0.1%.
The distribution of some nitrogenous constituents in the tea plant
Authors: Selvendran R. R. , Selvendran S. 
Published: November 2006

AbstractA survey was made of the various nitrogenous constituents of the tea plant using paper chromatography. The following parts of the plant were examined: leaves, bark and wood of stems and roots, feeder roots and fruits (pericarp and cotyledons).Theanine was present in every organ except the fruit and tended to be the major amino acid of the plant. Glutamic acid, aspartic acid and glutamine also occurred universally and in relatively high concentrations, and serine, alanine and γ‐aminobutyric acid, though generally present, occurred in smaller quantities. The wood of stems and roots contained appreciable quantities of a ninhydrinreactive compound which streaked like histidine. Pipecolic acid was present in appreciable quantities only in the fruits.The amino acids of the hot‐water‐soluble proteins of the various tissues have been determined and certain differences between them were noted.
Sulphite‐binding power of wines and ciders. I. Equilibrium constants for the dissociation of carbonyl bisulphite compounds
Authors: Burroughs Leonard F. , Sparks Arthur H. 
Published: November 2006

AbstractThe apparent Equilibrium Constants were determined at pH3 and 4 for the dissociation of the bisulphite compounds of acetaldehyde, pyruvic acid, 2‐ketoglutaric acid, L‐xylosone, D‐threo‐2,5‐hexodiulose, 2,5‐diketogluconic acid, 2‐ketogluconic acid and galacturonic acid. Determinations were also made over a wider pH range for acetaldehyde (pH 1 to 13) and pyruvic acid (pH 1.5 to 8).