bluuebunny/crossref_metadata_2025_split huggingface dataset:
Citric acid and the browning of solutions containing ascorbic acid
Authors: Clegg K. Mary 
Published: November 2006

AbstractModel systems were used to simulate lemon juice so that the findings may be applicable to the non‐enzymic browning phenomenon which occurs on storage of citrus juices. The addition of citric acid to systems containing ascorbic acid resulted in augmented chromophore development. Evidence is given to show that citric acid neither acts as a catalyst nor yields reactive carbonyl compounds under aerobic incubation conditions. Thin‐layer chromatographic separation of the brown pigments in different systems demonstrated a specific chromophore which occurred only when citric acid and ascorbic acid were both present. The presence of amino acids in ascorbic systems is the major contributor to the development of browning but it is suggested that citric acid, or a derivative, is incorporated into some of the brown pigments.
Detection of changes in modulus and viscosity of wheat flour doughs by the “work technique” of muller et al
Authors: Bloksma A. H. 
Published: November 2006

AbstractAt a given total extension both the recoverable (elastic) and the irrecoverable (viscous) work, as determined by Muller et al.3 with the Brabender extensograph, depend on the modulus as well as on the viscosity of the test‐piece. A theoretical analysis shows that, at constant elastic extension, the elastic work depends on the modulus only, and is not affected by changes in viscosity. On the other hand, if a few simplifying assumptions are permitted, the total work at constant viscous extension depends on the viscosity, but not on the modulus. Therefore, plots of elastic work against (a function of) the elastic extension and of the total work against the viscous extension permit easier detection of changes in modulus and viscosity than do plots of elastic and viscous work against the total extension.
Organochlorine insecticide residues in wild birds in Britain
Authors: Walker C. H. , Hamilton G. A. , Harrison R. B. 
Published: November 2006

AbstractOrganochlorine insecticide residues in a wide range of wild birds and their eggs from all over Britain have been determined by gas‐liquid chromatography and paper chromatography. Higher residues were found in predatory species than in omnivorous or herbivorous species. To illustrate the residue pattern in predatory species analytical data for specimens of the Heron, Kestrel and Sparrow‐Hawk have been summarised. The source of the residues and their possible effects upon birds are discussed.
The breakdown of 14C‐chlorfenvinphos in soils and in crops grown in the soils
Authors: Beynon K. I. , Wright A. N. 
Published: November 2006

AbstractSoils of four different types were treated with a relatively high dosage level (15 ppm) of 14C‐chlorfenvinphos and were stored at about 22° for four months. After this time the following radio‐labelled compounds were detected in the moist soils: unchanged chlorfenvinphos, 1.0‐4.7 ppm; 1‐(2′4′‐dichlorophenyl)ethan‐1‐ol, 0.06‐1.0 ppm; 2,4‐dichloroacetophenone, 0.1‐0.5 ppm; desethyl chlorfenvinphos, 0.1‐0.2 ppm; (2′,4′‐dichlorophenyl)ethan‐1,2‐diol, <0.03 ppm; salts or conjugates of desethyl chlorfenvinphos, 0.05‐0.6 ppm; 2,4‐dichlorophenyloxirane, <0.005 ppm; 2,4‐dichlorophenacyl chloride, <0.005 ppm.Soils were also treated with 3‐4 lb/ac 14C‐chlorfenvinphos and cabbages, onions, and carrots were grown to maturity in the soils. The edible part of cabbages at harvest contained no detectable chlorfenvinphos or breakdown products of it when the limit of detectability was about 0.005 ppm. At harvest at 8‐10 weeks after soil application of chlorfenvinphos the edible roots of carrots contained 0.12 ppm of unchanged chlorfenvinphos, and onion bulbs contained 0.07 ppm. There was evidence of trace amounts of a compound, probably a salt or conjugate of desethyl chlorfenvinphos, in onions (<0.01 ppm) and in carrots (0.024 ppm or less). Carrots also contained traces (about 0.005 ppm) of 2,4‐dichloroacetophenone.
A note on the influence of kernel hardness on the extractability of wheat proteins
Authors: Williams Philip C. , McEwin Nola M. 
Published: November 2006

AbstractBy using different grinding techniques, which resulted in whole wheatmeals ranging from 0.5 to 2.0 mm in particle size, it was shown that the amount of protein which could be extracted from the coarser meals was significantly less than that which could be extracted from fine meals. The standard error per determination was also higher for the coarser meals. The differences in extractability were significantly correlated with kernel hardness, but not with protein content. The significance of the findings is discussed in relation to modern colorimetric methods of protein determination.
Resolution and analysis of total phenolic constituents of grape pigment
Authors: Somers T. C. 
Published: November 2006

AbstractA procedure for the analysis of plant phenolics is described which allows the quantitative isolation of the high‐molecular‐weight tannin fraction, the separation of acylated anthocyanins from other anthocyanins, and the further partial separation of the monomeric polyphenols by adsorptive partition within each zone. The system used is a column of Sephadex G‐25 gel prepared in an aqueous acetone medium at low pH and eluted with the same solvent.By this means, an extract of the pigment from a single berry of Vitis vinifera cv. Shiraz has been separated into three distinct pigment fractions, the first of which, a red tannin pigment, was excluded from the gel. The second and third bands contained acylated anthocyanin 3‐glucosides and anthocyanin 3‐glucosides respectively, the components of each band being eluted in order of their decreasing RF in normal paper chromatography. Other phenolics of corresponding RF were found in each of these latter fractions.Pigment composition, expressed in terms of the three fractions, was calculated by use of mean extinction values. The red tannin pigment is the major fraction of total extractable pigment in the grape, although it is only a minor contributor to total colour of extracts.
Nutritive value of middle eastern foodstuffs. III.—Physiological availability of iron in selected foods common to the middle east
Authors: Cowan J. W. , Esfahani M. , Salji J. P. , Nahapetian A. 
Published: November 2006

AbstractThe physiological availability of the iron in selected foods of the Middle East was studied from haemoglobin regeneration in anaemic rats fed on diets in which these foods were the sole source of iron. None of the foods studied was as efficient as ferrous sulphate in promoting haemoglobin regeneration. Taking iron in ferrous sulphate as being 100% available, iron availability values for okra, chard and parsley were low, namely, 25, 45 and 48% respectively; other relative percentage values were: kidney bean, 59; lentil, 67; broad bean, 63; decorticated sesame, 67; parboiled wheat, 62; and brown bread, 75. The values for whole wheat and chickpea were greater than 80%. The availability of iron in prepared dishes and meals reflected that in the component foods. Since the iron in many plant foods seems to be much less available than inorganic iron, it is suggested that requirements for this nutrient should be reconsidered for areas such as the Middle East where the population derives a high proportion of dietary iron from plant sources.
Removal of volatile flavour constituents from foods prior to analysis by gas‐liquid chromatography
Authors: Lea C. H. , Swoboda P. A. T. , Hobson‐Frohock A. 
Published: November 2006

AbstractVolatile aroma constituents were removed from cooked chicken by vacuum distillation at 35°, followed by extraction of the aqueous distillate with ethyl chloride and concentration into a small volume of isooctane, to facilitate their analysis by gas‐liquid chromatography. In an alternative procedure the meat, powdered in liquid nitrogen, was extracted with ethyl chloride, and the volatiles were separated from the lipid extract by vacuum distillation and similarly concentrated for application to the column. The second method gave the better extraction, particularly for components of higher boiling point. Optimum sensitivity and reproducibility were achieved by transfer of the whole of a concentrated extract of the volatiles from e.g. 100 g meat in 1–3 ml of solvent on to a column previously cooled to ‐60° to ‐70°, followed by rapid heating to 31° and subsequent temperature programming to 200° in the usual way. Compounds of chain length C4 to C15 (at least) could be quantitatively transferred to the column and determined by this procedure.
The natural skin coating of the apple and its influence on scald in storage II.—Free fatty acids and carbonyl compounds
Authors: Meigh D. F. 
Published: November 2006

AbstractAnalytical results suggest that the free acids of the waxy coating of the apple have no influence on the incidence of superficial scald in cold‐stored fruit. Treatment of fruit with various free and esterified acids had no marked influence on scald, which suggests that oxidation products of these acids are also unconnected with scald. A long‐chain fatty aldehyde was found to be present in the wax. Two methods of scald prevention, wrapping in oiled paper and dipping in diphenylamine solution, were found to reduce the accumulation of this aldehyde in the waxy coating during storage. The evidence suggests that the scald‐promoting factor is formed in the waxy coating of the fruit by an oxidative process during storage, rather than by direct natural synthesis.
Pyrethrins and related compounds. IX Alkenylbenzyl and benzylbenzyl chrysanthemates
Authors: Elliott M. , Janes N. F. , Pearson B. C. 
Published: November 2006

AbstractThe syntheses of 4‐allylbenzyl, 4‐benzylbenzyl and other related benzyl chrysanthemates are described. The benzyl alcohols were made by reduction of benzoic esters if these were readily available; otherwise they were made either by Grignard reactions of appropriately substituted bromobenzenes with formaldehyde, or by reactions of alkenyl halides with Grignard derivatives of bromobenzyl alcohols in which the hydroxyl group was protected as its tetrahydropyranyl ether.
Chlorosis induced by substituted benzoic acids and related compounds
Authors: Dimmock J. R. 
Published: November 2006

AbstractA number of derivatives of 4‐hydroxy‐3‐nitrobenzoic acid and 4‐methoxy‐3‐nitrobenzoic acid and related compounds have been prepared, and their ability to produce chlorosis in six different species of plants has been examined. This series of compounds caused white and yellow areas to appear in the young tissues of the plants. A representative ester, ethyl‐4‐methoxy‐3‐nitrobenzoate, which caused this effect in barley was shown to affect the iron content and to reduce the quantity of pigments significantly. The structural requirements within this series of compounds for producing the type of chlorosis concerned are briefly discussed.
Roughages for ruminants — Net energy value in relation to chemical composition
Authors: Armstrong D. G. 
Published: November 2006

AbstractThe use of net energy values as measures of the nutritive value of roughages is discussed and reference is made to the principal energy‐yielding substrates present. Using data obtained for twelve dried grasses the relationships between net energy values for maintenance and for fattening and single constituents of the dry matter are examined. A comparison of the energy values determined for seven forages, with values predicted from their contents of crude protein, crude fibre or lignin has also been made. These studies suggest that the determination of hemicellulose, cellulose or lignin contents offers little advantage over the determination of acid‐detergent fibre or of crude fibre for predicting energy values.Predictions of energy values based upon in vitro digestibility determinations have been found to compare favourably with those based upon chemical analysis. The determination of in vitro digestibility has the added advantage that it may also give some guide to voluntary intake and hence reflect more fully the nutritive value of a roughage.
Evaluation of maize gluten meal as a protein source in egg production with and without supplements of L‐lysine and DL‐methionine
Authors: Squance E. , Jackson N. 
Published: November 2006

AbstractMaize gluten meal has been examined as the sole source of supplementary protein in cereal‐based high energy diets for caged hens and compared with a high energy diet containing white fish meal. Three levels of maize gluten meal were fed, 8.25, 12.25 and 15.25%, with and without supplements of L‐lysine HCl or L‐lysine HCl and DL‐methionine to provide total crude protein of 12.9, 16.1 and 18.7% in the diets.Egg production on the unsupplemented maize gluten meal diets was lower than for the fish meal diet. The production data for the diets containing 8.25, 12.25 and 15.25% maize gluten meal showed a significant rise in production with each addition of protein. The addition of lysine to the maize gluten meal diets also caused a significant increase in production at each protein level. Methionine supplements did not improve the performance of the diets already supplemented with lysine.Improvements in food conversion efficiency were directly related to the effects of treatment on egg production. The white fish meal diet gave the best food conversion efficiency. The most economic of the maize gluten meal diets contained 12.25% maize gluten meal supplemented with lysine. Egg yolk colour was significantly improved by the addition of maize gluten meal to the diets but pigmented flesh was noted in the birds receiving these diets. For maximum egg colour a level of maize gluten meal well below 8% would seem adequate.
Physico‐chemical studies on agricultural sprays VIII.—Viscosity and spray drop size of water‐in‐oil emulsions
Authors: Ford R. E. , Furmidge C. G. L. 
Published: November 2006

AbstractThe effect of the viscosity of the spray fluid on the size of drops produced from fan‐jet nozzles is complex; an increase in viscosity can lead to either an increase or a decrease in the drop size. With water‐in‐oil emulsions the value of the viscosity governing spray behaviour is the limiting value measured under conditions of very high shear.The factors which influence the limiting value of the viscosity include the disperse phase ratio, the method of mixing and the degree to which the two phases are mixed, the nature and concentration of the emulsifying agents used and the type of toxicant incorporated in the emulsion. Within certain limits, it is shown that the disperse phase ratio provides a convenient means of varying the viscosity of the emulsions and that the viscosity may also be varied by variations in the emulsifying agents and toxicants. Although the method of mixing has a considerable effect on the viscosity of the emulsion, the further mixing that takes place in the spray nozzle governs the effective viscosity of the spray fluid that is emitted from the nozzle.The practical application of the theoretical expressions which describe the formation of drops from fanjet nozzles has been discussed and the relationship between disperse phase ratio, viscosity, nozzle size and operating pressures has been illustrated for several typical water‐in‐oil emulsions.
Quantitative analysis of water‐soluble fertilisers by aqueous solution infra‐red spectroscopy
Authors: Goulden J. D. S. , Manning D. J. 
Published: November 2006

AbstractA method has been devised for the determination of ammonium, nitrate, phosphate and sulphate in water‐soluble artificial fertilisers. The infra‐red absorption spectra of suitably prepared aqueous fertiliser extracts were recorded and the absorbences measured at the appropriate four wavelengths. Results calculated from these absorbences gave ammonium concentrations which agreed with those obtained by chemical analysis to an accuracy of about 0.1% at the 10% level, whilst the nitrate and phosphate results agreed to about 0.3%.
Content of rhodanidogenic glucosides in some Brassica crops
Authors: Josefsson E. 
Published: November 2006

AbstractThe method of Aldridge has been used in order to investigate the content of thiocyanate‐yielding glucosides in Brassica crops, and methodological investigations have been made. Variation in thiocyanate‐yielding glucosides was examined in relation to harvest times, different morphological parts of the plant, older and younger parts of the plant, total populations, and individual plants. The content of thiocyanate‐yielding glucosides was highest at an early stage of the growth period and higher in the younger than in the older parts of the plant. In marrow‐stem kale the content was highest in the lamina, and in turnip rape the highest content was in the root, while the differences between the morphological parts of the rape variety were less marked. Evidence is presented that the content of the thiocyanate‐yielding glucosides is partly genetically controlled.
Effect of sodium chloride and moisture content on ammonification and nitrification in incubated soil
Authors: Sindhu M. A. , Cornfield A. H. 
Published: November 2006

AbstractA study was made of the effect of different soil moisture contents (from near the wilting point to water‐logging) combined with various levels of added sodium chloride (0.5‐2.0%) on the accumulation of mineral nitrogen (ammonia plus nitrate) during incubation (30°) of a neutral clay loam for 3 and 6 weeks. The optimum moisture content (50% m.w.h.c.m.w.h.c.=maximum water‐holding acapacity
) for mineralisation and nitrification was not affected by addition of sodium chloride. The most pronounced effect of sodium chloride in reducing mineralisation and nitritification occurred at the lowest moisture content and was very marked even at the lowest level (0.5%) of sodium chloride. Nitrification was completely suppressed by 1‐2% sodium chloride at all moisture contents but ammonification continued even with 2% sodium chloride. The presence of 1‐2% sodium chloride resulted in loss of nitrate at both low and high moisture contents, whilst 0.5% sodium chloride caused loss of nitrate only at 25% m.w.h.c.
Residual mercury content of seed potatoes treated with organo‐mercury disinfectant solutions
Authors: Hamilton G. A. , Ruthven A. D. 
Published: November 2006

AbstractBefore export from Scotland, certain seed potatoes are mechanically washed and then dipped in organo‐mercury fungicide solutions to control tuber‐borne diseases. During transit and after receipt, these potatoes may be accidentally eaten by humans or animals, and the work reported here was done to find out whether the mercury residues reach a level likely to constitute a toxic hazard. Analyses were carried out on both cooked and uncooked whole potatoes, and on the peel and the flesh. The potatoes were stored and analysed at intervals over a period of time comparable with the time taken during export. The effect of haulm destruction on the subsequent uptake of the disinfectant was investigated. Also included are analyses of tubers which were dipped in organo‐mercury solutions after being washed over different types of rollers in a commercial machine. The results indicated that the levels of mercury present would make treated potatoes unacceptable for consumption. However, potatoes grown from treated seed were found to contain very small amounts of mercury, which were no greater than untreated control material, and which were of no toxicological significance.
Studies on potassium nutrition of plants. II.—Some effects of potassium deficiency on the organic acids of leaves
Authors: Freeman G. G. 
Published: November 2006

AbstractLeaf organic acids of a series of plants have been determined by silica gel chromatography. Red beet and cabbage were grown in sand culture at six levels of potassium nutrition ranging from extreme deficiency to high potassium concentration. Potassium deficiency in cabbage, beet and potato leaves resulted in large increases of total organic acids, whereas there was a decrease in lettuce and no effect in Italian rye grass.Volatile organic acids of cabbage leaf were quantitatively minor components but at two extreme levels of potassium nutrition, they were present in the same relative proportions as total organic acid. Shikimic acid was tentatively identified in field‐grown rye grass (0.96% of dry weight).
Formation of higher alcohols by wine yeasts, and relationship to taste thresholds
Authors: Rankine B. C. 
Published: November 2006

AbstractThe amounts of n‐propanol, iso‐butanol and iso‐amyl plus active amyl alcohol produced during fermentation of grape juice were found to vary considerably according to the yeast used. The yeasts studied included 11 wine yeasts and one brewery yeast, all belonging to the genus Saccharomyces, and 4 yeasts belonging to genera which sometimes cause wine spoilage. Experiments were carried out in the laboratory and confirmed on pilot‐plant scale.The average production of n‐propanol in juices from 4 grape varieties varied from 13 to 106 ppm depending on the wine yeast used. The corresponding variations in the production of iso‐butanol and isoamyl plus active amyl alcohol were 9 to 37 ppm and 115 to 262 ppm respectively,. Juices from different varieties' of grapes (Vitis vinifera) differed somewhat in the amounts of higher alcohols formed, irrespective of the yeast strain used.An increase in temperature of fermentation from 15° to 25° with four yeasts produced an average of 24% more iso‐amyl plus active alcohol and 39% more iso‐butanol, and 17% less n‐propanol. A yeast/temperature interaction occurred.An increase in pH from 3.0 to 4.2 with four yeasts produced 28% more iso‐amyl plus active amyl alcohol, 85% more iso‐butanol, and 11% more n‐propanol. A yeast /pH interaction occurred.Spoilage yeasts examined also formed higher alcohols and the amounts were not related to sugar consumed during the fermentation.Taste thresholds of the higher alcohols, with the exception of active amyl alcohol, were measured in dry white wine with 7 tasters. Iso‐amyl alcohol thresholds ranged from 100 to 900 ppm (mean 300 ppm) and iso‐butanol and n‐propanol both exceeded 500 ppm. The average threshold of iso‐amyl alcohol in distilled water was 4 ppm. For certain tasters strains of yeast can produce sufficient differences in iso‐amyl alcohol to be detectable organoleptically, but differences in iso‐butanol and n‐propanol are not large enough to be detectable.
Antioxidants in oats: Mono‐esters of caffeic and ferulic acids
Authors: Daniels D. G. H. , Martin H. F. 
Published: November 2006

AbstractTwo‐dimensional thin‐layer chromatography has shown the presence of 24 phenolic antioxidants in oats, and the present paper deals with the identification of five of these. Two of them have been isolated by column chromatography and characterised. One consists of the homologues, n‐hexacosyl caffeate and n‐octacosyl caffeate (proportions, 3:1, approximately) and the other, 26‐O‐caffeoyl‐26‐hydroxy‐hexa‐cosanoic acid with 28‐O‐caffeoyl‐28‐hydroxyoctacosanoic acid (proportions, 3:1, approximately).Evidence is presented for the probable structures of the remaining three antioxidants, based on two‐way thin‐layer chromatographic comparison with the synthetic ferulates: n‐hexacosyl ferulate, 26‐O‐feruloyl‐26‐hydroxyhexacosanoic acid and hexacosane‐1,26‐diol monoferulate. The preparation of these ferulates is described, and in addition, that of two caffeates, n‐hexacosyl and n‐dodecyl. The antioxidant activities of the above compounds were measured.
Long‐term residues arising from 14CO2 fixation in swine tissues
Authors: Schach Von Wittenau M. 
Published: November 2006

AbstractPigs injected intramuscularly with 14C sodium earbonate solution were killed after 9 and 21 days. The protein hydrolysate from liver tissues were treated with ninhydrin to liberate CO2 which was used for determination of residual radioactivity. Most of the 14C from the fixed CO2 was liberated by this treatment, which was considered to be a suitable method for estimating long‐term residues of 14C in tissues arising from a 14CO2 fixation process. The proportion of 14C in various amino acids remained almost constant over the period of the test.