bluuebunny/crossref_metadata_2025 huggingface dataset:
Emission of nitrous oxide to the atmosphere from direct‐drilled and ploughed clay soils
Authors: Burford John R. , Dowdell Rodney J. , Crees Rachel
Published: October 2006

The emission of nitrous oxide to the atmosphere was measured for 2 years (1977‐79) from two clay soils (Denchworth and Lawford series) that had either been directdrilled or ploughed. On almost all sampling occasions the emission from directdrilled plots exceeded that from the ploughed plots by factors ranging up to 15‐fold. Rates of nitrous oxide loss reached peaks of 2.5‐3.0 mg N m‐2 h‐1 (equivalent to 0.6‐0.7 kg N ha‐1 day‐1) from the direct‐drilled plots on the Denchworth soil. Emissions of nitrous oxide from the Lawford soil were only 10‐20% of those from the Denchworth soil. The total amount of nitrous oxide‐N lost during each year from the Denchworth soil was estimated to be 5.4‐8.6 kg N ha‐1 from the direct‐drilled plots and 0.9‐5.6 kg N ha‐1 from the ploughed plots.
Scanning electron microscopy studies of wheat protein fractions from doughs mixed with oxidants at high temperature
Authors: Nagao Seiichi , Endo Shigeru , Tanaka Kenji
Published: October 2006

Protein from flour and doughs mixed with a Do‐Corder at high temperatures in the presence and absence of oxidants (potassium bromate, potassium iodate and L‐ascorbic acid) was fractionated according to solubility into water‐, salt‐, alcohol‐, acetic acid‐soluble protein fractions and insoluble residue protein. All fractions were freeze‐dried and subjected to scanning electron microscopy to observe visually the changes in protein structure. Acetic acid‐soluble and insoluble residue protein are alike in structure, but the former was thermally denatured easily, while the latter was very stable to heat treatment. Salt‐ and alcohol‐soluble protein were not deformed, but the water‐soluble protein was deformed by heat treatment in the absence of oxidant. Oxidants generally promoted deformation of protein structure with the exception that bromate partly protected acetic acid‐soluble protein from deformation.
Changes in the limonin monolactone content during development of Washington Navel oranges
Authors: Casas A. , Rodrigo M. I.
Published: October 2006

A study of the changes in the limonin monolactone content of Washington Navel oranges, grown on sour orange rootstock, from blossom until maturity was carried out. At the same time the changes in the limonin monolactone content in the leaves from the spring‐flush, adjoining the fruits used in the investigation, were studied. From the start of development of the fruits there was an important biosynthetic activity of limonin monolactone, as indicated by its accumulation up to a maximum of 47 mg per fruit—around 130 days after anthesis. Throughout the whole development of the fruit the total limonin monolactone content in the endocarp was found to be greater than in the peel. The limonin monolactone content in the leaves decreased gradually from the start of the experiment until 130 days after anthesis.
Structural functions of taste in the sugar series: Function of the γ‐attribute in the sweet glycophore
Authors: Dziedzic Stanley Z. , Birch Gordon G.
Published: October 2006

The tastes of chlorinated derivatives of simple monosaccharides, their alcohols, and the disaccharides maltose and trehalose were examined in relation to existing theories of sweetness sensation. Conclusions have been drawn about the importance of the γ‐lipophilic constituent as the third site in the sweet glycophore and its function as a vector for sweet taste.
Changes in the lipid components of minced carp (Cyprinus carpio) following cooking
Authors: Mai Jimbin , Kinsella John E.
Published: October 2006

The changes in weight, moisture, lipid content and composition, thiobarbituric acid (TBA) and carbonyl values were determined in minced carp following cooking by baking and deep‐frying. Baked samples lost lipid via drip while the deep‐fried samples absorbed oil. Free fatty acids decreased following cooking. Thiobarbituric acid (TBA) values increased following cooking by either method. Antioxidants (TBHQ and BHA) inhibited the production of TBA‐reactive compounds though the production of carbonyls during deep‐frying was enhanced. Tertiary butylhydroquinone (TBHQ) was slightly more effective than BHA in inhibiting the formation of TBA‐reactive compounds.
Measurement of the degree of starch damage in flour by near infrared reflectance analysis
Authors: Osborne Brian G. , Douglas Stuart
Published: October 2006

The degree of mechanical damage imparted to starch granules during flour milling is of importance in relation to the baking properties of the flour. A calibration is presented which enables the degree of starch damage to be measured by near infrared reflectance. This technique is rapid and non‐destructive so facilitating quality control of a flour mill. The results obtained using 148 UK commercial flour samples were a correlation coefficient of 0.906 and a residual standard deviation of 3.5 Farrand units using 74 of the samples covering the range 6‐47 Farrand units. The calibration was obtained using log (1/R) data at 1442, 1580, 2060 and 2258 nm. The residual standard deviation increased to 4.2 Farrand units when the calibration was used to predict the values of 68 further samples of commercial flour. The wavelengths at which reflectance measurements were taken corresponded to overtones and combinations of vibration frequencies due to free and hydrogen‐bonded O—H bonds in starch.
A rapid test for identifying potential malting quality in the early generations of a barley breeding programme
Authors: Morgan Alan G. , Gothard Peter G.
Published: October 2006

The nitrogen content of barley grains and the viscosity and glucose content of an acid extract from the corresponding barley flour were used to predict, with sufficient accuracy for selection purposes, the hot‐water extract obtained after the samples were micro‐malted. Optimum procedures were established using grain samples from several varieties and environments. Prediction equations were obtained by multiple regression and tested using samples of spring and winter barleys from the Plant Breeding Institute breeding programmes. The accuracy of prediction was greater with spring than with winter barleys. Approximately 70 samples can be tested by one person in 1 day and only a small amount of seed (2 g) is required. The method is considered suitable for screening material from early generations of breeding programmes when numbers are high and quantities of seed are insufficient for micromalting.
An improved chemical extraction method for predicting the supply of available soil nitrogen
Authors: Whitehead David C.
Published: October 2006

An improved method for predicting the supply of available soil N has been developed, based on the concept of determining simultaneously the mineral N (NO3‐N+NH4‐N) present in the soil at the time of sampling, and the mineralisable N that would become available during the growing season through mineralisation of organic matter. The method entails the determination, by automated colorimetry, of NO3‐N and NH4‐N extracted from the soil by boiling with 1M KCl. The method was evaluated, in comparison with others, using 21 soils. The values for predicted soil N supply from the various methods were correlated with the amounts of N, summated over six harvests, in the herbage of perennial ryegrass grown on the soils in pots kept under uniform conditions. The method based on extraction by boiling with 1M KCl accounted for 80% of the variation between soils in herbage N yield. A second method, based on the determination of NO3‐N+NH4‐N extracted by 0.05M Ba(OH)2, was equally as effective but was considered less suitable for routine use.
The estimation of lysine by a simplified dansylation procedure
Authors: Smith Terence A. , Best Graham R.
Published: October 2006

A method is described for the estimation of free lysine which depends on its reaction with excess dimethylaminonaphthalene sulphonyl (dans) chloride to form dans‐5‐aminovaleraldehyde. This product is extracted into toluene, separated by thin layer chromatography and estimated by fluorimetry. The mean recovery of lysine added to casein hydrolysate using this method was 99% (s.e. 4.3%).
The lipids of young cassava (Manihot esculenta, Crantz) leaves
Authors: Khor Hun‐Teik , Tan Hui‐Ling
Published: October 2006

Lipids were extracted quantitatively from young cassava (Manihot esculenta Crantz) leaves with a chloroform‐methanol mixture. Total lipids were purified by the Folch procedure and separated into non‐polar lipid, glycolipid and phospholipid fractions by column chromatography. Lipids of each fraction were further subjected to thin layer chromatography and gas‐liquid chromatography. Young cassava leaves were found to have low content of lipids (3.02%) of which 22.4, 25.1 and 48.2 were non‐polar lipids, glycolipids and phospholipids, respectively. Pigments (11.5%), wax and hydrocarbons (1.2%), steryl esters (2.9%), methyl esters of fatty acids (2.0%), trigly‐cerides (1.5%), fatty acids (2.1%), diglycerides (1.1%) and sterols (0.1%) constituted the leaf non‐polar lipids. The leaf glycolipids were made up of esterified steryl glycosides (2.1%), monogalactosyl diglycerides (12.5%), steryl glycosides (1.1%), cerebrosides (4.2%) and digalactosyl diglycerides (5.2%). The leaf phospholipids were found to include cardiolipin (3.6%), phosphatidylglycerol (21.5%), phosphatidylethanolamine (16.4%), phosphatidylserine (0.7%), phosphatidylinositol (4.0%) and other unidentified phospholipids (2.5%). Phosphatidylcholine was present only in trace quantity. Analysis of the fatty acid composition of each of the leaf lipids revealed that, with the exception of steryl esters, all leaf lipids have high content of polyunsaturated fatty acids.
Electrophoretic separation and properties of winged bean seed trypsin inhibitor
Authors: Hildebrand David F. , Hettiarachchy Navagnana S. , Hymowitz Theodore , Erdman John W.
Published: October 2006

Separation of the major trypsin inhibitor protein from crude extracts of winged bean seeds (WBTi) was accomplished using a cathodic polyacrylamide disc gel electrophoretic system. The molecular weight of the WBTi protein was determined to be about 20 000. Winged bean seed extracts showed trypsin‐inhibiting (Ti) activity similar to soya bean seed extracts, but large genotypic differences of the Ti activity in winged beans were found. Preliminary studies on the effects of processing on WBTi indicate that aqueous extracts of WBTi are at least as heat‐labile as the Ti of aqueous extracts of soya bean seeds. Autoclaving winged bean seed meal prior to protein extraction resulted in considerable reduction of protein solubility.
Lipolytic activity of fungi on rapeseed oil
Authors: El Azzabi Taher S. , Clarke James H. , Hill Simon T.
Published: October 2006

Many species of fungi grow on stored seeds of oilseed rape causing the development of high levels of free fatty acids. However, the presence of a fungus on the seed does not imply that it is lipolytic. The work reported here was performed to test the ability of fungi isolated from stored rapeseed to release fatty acids from refined rapeseed oil. Lipolytic activity was assessed by growing fungi on agar, incorporating the oil as droplets and the indicator Nile blue sulphate. Of 18 species tested, only Aspergillus versicolor showed no lipolytic activity. Another method of testing for lipolysis was used for three of the fungi. They were grown in a liquid medium containing oil and the amount of free fatty acids was measured titrimetrically. The results show that many fungi can cause lipolysis of rapeseed oil, but there are great differences in the lipolytic activity between species.
Constitution of leguminous seeds. The effect of some physico‐chemical factors on the yield of proteins isolated from Phaseolus beans
Authors: Alli Inteaz , Baker Bruce E.
Published: October 2006

The yields of acid‐soluble proteins isolated from white kidney beans (Phaseolus vulgaris), navy beans (P. vulgaris) and baby lima beans (P. lunatus) were determined under different conditions of extraction. Highest yields of protein material were obtained when malic acid solutions [0.4M (pH 3.5) white kidney bean and navy bean; 0.05M (pH 3.5) baby lima bean] were used and under the following conditions: shaking time 20‐30 min; extraction temperature 40‐45°C; particle size 0.50‐1.00 mm.
Artificial gravel produced by sintering soil
Authors: Hautala Earl , Menefee Emory
Published: October 2006

A montmorillonite‐type clay soil was sintered at 800°C to form a permeable gravel substitute suitable for use as a drainage envelope material. Compression testing showed the sintered soil to be water‐stable with deformation characteristics that resemble sand more than the original soil. Hydraulic conductivity of the soil was increased more than ten‐fold by sintering. The economics of sintering may be favourable depending on the costs of mining and hauling gravel from local deposits.
Analysis of yield of winter wheat grown at increasing levels of potassium
Authors: Haeder Hans E. , Beringer Helmut
Published: October 2006

Winter wheat was grown in pots receiving 0 (K0), 60 (K1) and 120 (K2) mg K 100 g−1 soil to investigate the effect of potassium (K) supply on the following yield components: number of ears, number of grains per ear and single grain weight. Mature grain yield increased from 34.5 g per pot at K0 to 81 g at K1 and 89.9 g per pot at K2. Straw yield increased from 35.4 (K0) to 123.2 g per pot (K2), reflecting an increase in leaf area and photosynthesis. K fertiliser lengthened the period of grain filling by 3‐4 weeks both by advancing anthesis and delaying senescence. The longer grain filling period fed by more abundant assimilates resulted in single grain weights of about 40 mg in central and lower spikelets and as much as 30 mg in the apical spikelets.
Influence of potassium nutrition and water stress on the content of abscisic acid in grains and flag leaves of wheat during grain development
Authors: Haeder Hans E. , Beringer Helmut
Published: October 2006

Increasing the potassium (K) supply to wheat plants grown in pots extended the period of grain filling and increased the rate of grain growth, thus increasing the single grain weight. In all K treatments abscisic acid (ABA) content in the grain reached a maximum and this occurred when the growth rate of the grain declined and full ripening commenced. Increasing the K supply delayed the occurrence of the ABA maximum and reduced its absolute value. It seems that an extension of the grain filling period by better K nutrition might not only be due to a longer production of assimilates, but also due to a retarded and lower production of ABA in the grain. This result is supported by the finding that withholding of water supply for 1‐week periods during grain development increased ABA content in the grain and reduced single grain weight.
The metabolism of alcohols by apple fruit tissue
Authors: Knee Michael , Hatfield Stephen G. S.
Published: October 2006

The interconversion of short‐chain aliphatic alcohols, aldehydes and esters by apple fruit has been studied by gas‐liquid chromatographic analysis of the products when substrates (mainly alcohols) were supplied as vapours to fruit slices at 20°C, and to whole fruit during storage at 3°C. In preliminary experiments with fruit from various sources after different periods of storage, cortical tissue slices formed corresponding aldehydes and acetate esters from alcohols; esterification was more rapid with higher alcohols. Esterification by peel tissue slices was more rapid initially but quickly declined. Metabolism was further investigated with a batch of apples during storage under different conditions. Both cortex and peel tissue were capable of acetylating butanol and 2‐methyl propanol at all stages of maturity, from the pre‐climacteric state at normal harvest time, when endogenous ester levels were low, through 58 days ripening at 12°C. The tissues showed constant hydrolytic activity towards butyl acetate throughout this period. Whole apples in air and 2% O2 at 3°C took up ethanol but formed little ethyl acetate and retained very little free ethanol. In both atmospheres whole apples metabolised approximately 40% of added hexanol to hexyl acetate and up to 8% to hexanal. The low levels of esters in apples from low oxygen atmospheres (and the absence of esters in unripe apples) are, therefore, a consequence of low rates of alcohol synthesis.
The reactivation of ‚exhausted’︁ cellulose acetate gel beads used commercially for debittering orange juice
Authors: Johnson Robert L.
Published: October 2006

Cellulose acetate gel beads, when used commercially for removing the bitter principle, limonin, from orange juice, may eventually become so loaded with organic matter that simple water washes are no longer adequate to reactivate them. Such exhausted beads may be readily and economically restored to their original activity by washing with a small volume of warm water which is recycled through a small active carbon bed. Evidence is presented to indicate that limonin and hesperidin are not the only adsorbed compounds involved in loss of bead activity.
Patulin production by Paecilomyces species isolated from silage in the United Kingdom
Authors: Hacking Arthur , Rosser William R.
Published: October 2006

Twenty‐six Paecilomyces spp. isolated from silage in the UK were tested in a potato dextrose broth for the ability to produce the mycotoxin patulin. Of the 26 isolates 21 were shown to be capable of producing patulin. The ability of such isolates to produce patulin does not seem to be influenced by the grass species ensiled nor the pH of the silage. Patulin was not detected in any of the silage samples.
Nutritive value of cassava root meal enriched by trichoderma harzianum for chickens
Authors: Muindi Pancras J. , Hanssen Jon F.
Published: October 2006

A study was conducted with chickens to establish the content of metabolisable energy (ME) and the content and apparent digestibility of crude protein (CP) and amino acids (AA) in cassava root meal (CRM) enriched by the fungus Trichoderma harzianum. The ME content of this enriched CRM was found to be about 9.1 MJ kg−1 dry matter (DM). This value was significantly lower (P<0.05) than that of non‐enriched CRM (12.2 MJ kg−1 DM). The CP content of the enriched CRM product used was 37.6 on DM basis. The non‐protein nitrogen content accounted for about 30% of the total CP value. The mean apparent digestibility coefficient of the CP was about 66% whereas that of AA was about 81%. Data from this study indicate that fungal enriched CRM could be used in chicken diets.
The baking quality and protein characteristics of a winter wheat grown at different levels of nitrogen fertilisation
Authors: Timms Michael F. , Bottomley Robin C. , Ellis J. Richard S. , Schofield J. David
Published: October 2006

Three samples of field‐grown winter wheat (Triticum aestivum cv. Atou) with different protein contents were produced by late application of urea as a nitrogenous fertiliser. Baking tests (a conventional fermentation procedure) indicated that the breadmaking quality of the flours increased as protein content was raised from the lowest to the intermediate level, but that the flours of intermediate and highest protein content were of equivalent breadmaking quality. To compare gluten baking quality independently of protein quantity, loaves were also baked from ‘flours’ reconstituted to equivalent protein levels using the isolated glutens. The flours of low and intermediate protein content yielded glutens of similar baking quality. The gluten derived from the flour of highest protein content gave a lower loaf volume and texture score: subsequent biochemical investigations suggested that this was due to an effect of the relative levels of nitrogen and sulphur available to the plants grown on this particular soil. Analysis of the flours and glutens indicated that the ratio of sulphur:nitrogen fell as grain protein content increased and this correlated with a lower proportion of the sulphur amino acids cyst(e)ine and methionine. Gel electrophoresis studies revealed, in particular, an increase in the proportion of the sulphur‐deficient, ω‐gliadin species as grain protein content increased. Agarose gel filtration chromatography of the flour and gluten proteins also suggested a correlation between the extent of aggregation of their glutenin components (mediated by disulphide bonds involving cystine residues) and their functional properties. The results of this study suggest that for wheat grown on this particular soil late application of high levels of a nitrogenous fertiliser in the absence of sulphur fertilisation led to a change in the balance between available nitrogen and available sulphur, such that the available sulphur levels became insufficient for ‘normal’ grain development. Nevertheless, the results indicated that considerable alteration in the biochemical characteristics of the flour proteins occurred before gluten baking quality was noticeably affected.
Use of ion exchange resins in the extraction of proteins from defatted groundnut and soya flours
Authors: Satyanarayana B. L. , A. Sulebele Guruprasad , V. Rege Dinanath
Published: October 2006

A novel method of extraction of proteins from defatted oilseed flours by anionic and cationic exchange resins is described. Extraction was performed under varying conditions with respect to type of resin, resin:flour ratio, flour:water ratio and temperature, and the optimum conditions determined. Amberlite IRC‐50 (Na+) and Zeokarb‐225 (Ca2+) extracted 92.0 and 96.5% of the proteins from defatted groundnut flour, respectively. Zeokarb‐225 (Na+) extracted nearly 66.0% of the proteins from defatted soya flour. Ion exchange resins were superior to alkaline extractants for the solubilisation of proteins from these oilseed flours.
International collaborative study of an automated method for the determination of crude protein in fish‐meals
Authors: Barlow S. M. , Bimbo A. , Jensen O. Bjørn , Smith G. L.
Published: October 2006

An automated macro‐Kjeldahl instrument (Kjel‐Foss) determines protein at the rate of 20 samples in 1 h. The methodology is similar to the Kjeldahl method officially recommended by the IAFMM for fish‐meal. The two methods were compared in a collaborative study. Six fish‐meals, tryptophan and acetanilide were analysed by 15 participating laboratories. The results showed good agreement between the two methods. There was little difference between the two methods in terms of repeatability in the laboratory, but variability between laboratories was significantly less when the automated method was used.
Ammonia concentration and protein synthesis in the rumen
Authors: Pisulewski Pawel M. , Okorie Al U. , Buttery Peter J. , Haresign Wilhain , Lewis Dyfed
Published: October 2006

The effect of rumen ammonia concentration on microbial protein synthesis and fermentation was studied in three separate experiments. In each experiment three separate sheep were fed semi‐purified diets [designated A (‘concentrate’), B (‘roughageconcentrate’) or C (‘roughage’)] and infused intra‐ruminally with five graded amounts of urea according to a randomised block design. Rumen ammonia concentrations remained low until the total nitrogen intake was about 10 g day−1 after which rumen ammonia concentration rose rapidly. Rumen and duodenal ammonia concentrations were linearly related (r=0.90, 0.98 and 0.84 for diets A, B and C, respectively; P< 0.001). Microbial protein production did not increase when rumen ammonia concentrations exceeded 2.8 mM for diet A, 6.0 mM for diet B and 1.6 mM for diet C. Diets A and C produced a propionate‐type fermentation while diet B was characterised by an acetate‐type fermentation. Rumen ammonia concentration had no apparent effect on either concentration or the molar proportions of volatile fatty acids. There were no systematic trends in digestibility in relation to rumen ammonia concentration.
Gliadin proteins in the developing wheat seed
Authors: Mecham Dale K. , Fullington J. Garrin , Greene Frank C.
Published: October 2006

In extracts of developing seeds of wheat (Triticum aestivum L., cultivars Scout 66, Cheyenne, Nugaines and INIA 66R) examined by polyacrylamide gel electrophoresis, gliadin proteins appeared at 12‐15 days post‐anthesis with mobilities covering nearly the whole range found with mature seeds. Some differences among extractants [2M dimethylformamide (DMF); 2M urea; 60% ethanol; the aluminium lactate‐lactic acid electrophoresis buffer, pH 3.2] in both intensity and occurrence of specific bands were observed. With immature seeds, 60% ethanol extracts produced a maximum number of bands and least background colour, but DMF and urea extracts showed bands from 12‐ to 15‐day seeds at least as well as 60% ethanol extracts despite more background colour. Aluminium lactate buffer extracts occasionally yielded bands not found with other extractants, but gave poor extraction from immature seeds and relatively heavy background staining with mature seeds, especially in the w‐gliadin (lowest mobility) region. A quantitative sodium dodecyl sulphate‐electrophoresis procedure1 was used to follow the formation of proteins in various molecular weight ranges (cv. Scout 66 only). At 12‐18 days post‐anthesis, synthesis of protein of molecular weight 30 000‐37 000 accelerated, consistent with the onset and acceleration of formation of α‐, β‐, and some y‐gliadins. Protein in a band of 44 000 molecular weight formed in similar fashion. In other molecular weight ranges, gliadin bands could not be positively identified because of the complexity of the banding pattern of the total protein.
Studies on the flow and composition of bile in growing pigs
Authors: Sambrook Ian E.
Published: October 2006

A method is described for measuring the rate of flow and composition of bile entering the duodenum of the pig with minimal interference to the normal physiological processes of bile secretion. Eight pigs of 25‐30 kg initial liveweight were fitted with reentrant catheters in the common bile duct. Two different diets were used: these contained barley, fine wheat offal, white fish‐meal, minerals and vitamins (diet BWF), starch, sucrose, casein, maize oil, cellulose, minerals and vitamins (diet SSC). The flow of bile in 24 h was calculated from the rate of drop formation in a small Perspex drop chamber. Variation in flow between and within pigs was high. Mean values for total flow of bile, and of water, dry matter, ash, total lipid and total nitrogen in the bile were: 1733, 1656, 76.9, 18.6, 11.0, 1.9 g 24 h‐1, respectively, for diet BWF, and 1182, 1132, 49.7, 12.6, 8.1, 1.8 g 24 h‐1, respectively, for diet SSC. The hourly pattern of bile flow appeared different for the two diets; for both diets, however, bile was calculated to contribute a maximum of 15% of the total endogenous material added to digesta collected from the duodenum.
Detection and partial characterisation of subtilisin inhibitors in legume seeds by isoelectric focusing
Authors: Chavan Jayasing K. , Hejgaard Jørn
Published: October 2006

Seed extracts of ten legume species were subjected to isoelectric focusing in acrylamide gels and inhibitors of subtilisin, three other bacterial proteases, trypsin and chymotrypsin were detected by a negative‐staining technique based on the chromogenic substrate, acetyl‐D, L‐phenylalanine‐2‐naphthylester. In addition to complex patterns of trypsin and chymotrypsin inhibitor zones, most legume seeds examined exhibited one major and one minor inhibitor of subtilisin, and the other bacterial proteases. However, in cowpea and black gram only the major, and in lentil and soya bean only two minor subtilisin inhibitor zones were detected. Isoelectric points of the subtilisin inhibitors range from 4.4 to 5.9. The inhibitor patterns obtained by isoelectric focusing of extracts mixed with bacterial protease confirmed that inhibitors of the bacterial proteases represent a new type of inhibitor different from the well characterised trypsin and chymotrypsin inhibitors.
The composition of milk of the friesian cattle imported into Nigeria
Authors: Akinsoyinu Akintunde O.
Published: October 2006

Here the results of analyses of milk of Friesian cows imported into the University Teaching and Research Farm from Western Germany are reported. Twenty‐five of the cows were milked from the first day after parturition for a lactation of 305 days (average yield 3000 ± 88kg). The colostrum contained higher percentages of total solids (TS), crude protein (CP), fats and ash but lower lactose than the mature milk. Concentration of major minerals in the colostrum were higher than the corresponding values in the mature milk. The composition of the colostrum approached normal values on the seventh day after parturition. Contents of TS, CP, lactose and fats in milk were highest in the first month of lactation and then decreased with advance in lactation. The trends were highly significant (P<0.01). On the other hand, the concentration of the minerals increased except for potassium which decreased with advance in lactation with the trends being highly significant (P < 0.01). The values obtained for the gross composition of milk (except total ash) were higher than those reported for the Friesian cow's milk in temperate countries.
Preparations for the reclamation of a lagoon containing canal dredgings contaminated with heavy metals including mercury
Authors: Edwards Philip R. , Pumphrey Nicholas W. J.
Published: October 2006

The uptake of trace metals, in particular mercury, into crops from contaminated canal dredgings contained in a lagoon has been studied in field trials and other experiments. In none of these experiments was it possible to demonstrate a significant difference (P<0.05) between mercury or other metal concentration in plants exposed to the contaminated dredgings and in plants grown as controls. No problem with metal contamination of crops is anticipated when the lagoon is reclaimed for agricultural purposes but it will be necessary to cover the dredgings with 30 cm of soil to ensure adequate yields of shallow‐rooted crops.
Preservation of silage effluent
Authors: Patterson Desmond C. , Walker Norman
Published: October 2006

Three experiments have been carried out to investigate the storage of silage effluent and the value of formalin, formic acid and sulphur dioxide as preservatives. In the third experiment treatment with formalin was compared with sealing treatments using liquid paraffin, maize oil or polythene. This experiment was conducted on effluents with initial pH values of 3.8 and 4.6. All treatments except those sealed with polythene were challenged with a mould spore culture. The results obtained show that formic acid, formalin or sulphur dioxide can preserve silage effluent under aerobic conditions and appear to control mould growth. The higher the level of preservative the longer the interval to the onset of mould growth. None of the chemical measurements indicated when moulding would occur. Sealing provided an alternative storage method to chemical treatment and was particularly suitable when the pH of the effluent was higher than 4.5. The onset of mould growth appeared to accelerate the rate of chemical change in effluent.
The effect of cultivar and harvest date on the chemical composition and digestibility of fodder kale
Authors: Bradshaw John E. , Borzucki Ronald
Published: October 2006

The chemical composition and digestibility of seven marrow‐stem, three thousand‐head, and two curly kales were determined during the period from September to March. Differences between cultivars and between harvest dates were found for all of the characteristics assessed, but cultivar by harvest date interactions were not a serious problem. The largest differences in dry matter (DM) content were between the two curly kales (17.7%) and the other ten cultivars (14.0%), and between the mid‐September harvest (11.3%) and the three later harvests (15.8%). Then, expressed as a percentage of the DM, the main results were as follows. The organic matter (OM) content was low in the mid‐September (85.9 compared to 90.1) and contributed to a low digestible OM content (68.5 compared to 72.2). Amongst the marrow‐stem kales were the extremes for digestible OM, namely 68.6 in an un‐named marrow‐stem stock and 73.5 in Maris Kestrel. The crude protein content fell from 22.1 in mid‐September to 15.7 in mid‐November, and then rose to 17.4 in January and March. The S‐methyl cysteine sulphoxide (the haemolytic factor) content increased from 0.692 in mid‐September to 1.21 in January and March, when the curly kales had 41% higher contents than the marrow‐stem kales. The extreme thiocyanate ion (a goitrogen) contents occurred in mid‐November (0.0152) and mid‐January (0.0336), and ranged from 0.0157 in the marrow‐stem cultivar Merlin to 0.0334 in the dwarf thousand‐head cultivar Canson. Although not a yield trial, it was found that on average the DM yield of the curly kales was only 55% that of the marrow‐stem and thousand‐head kales.
Constitution of leguminous seeds. Scanning electron microscopy of proteins prepared from Phaseolus beans
Authors: Alli Inteaz , Baker Bruce E.
Published: October 2006

Proteins were isolated from citric acid and sodium hydroxide extracts of navy beans (Phaseolus vulgaris), white kidney beans (Phaseolus vulgaris) and baby lima beans (Phaseolus lunatus). Examination of the proteins under the scanning electron microscope revealed that several types of particulate micro‐structures were present in the proteins obtained by citric acid extraction of the beans followed by precipitation by cooling. Examination of the proteins obtained by extraction with sodium hydroxide solution and isoelectric precipitation revealed the presence of only one type of non‐particulate micro‐structure.
Evaluation of 18 apple varieties for their suitability for juice production
Authors: Poll Leif
Published: October 2006

Eighteen apple varieties have been evaluated both organoleptically and chemically for their suitability as raw material for apple juicep reduction. Fruits, for the main part, were evaluated in 1977 and 1978, and the few varieties showing significant differences were re‐evaluated in 1979. Large differences in aroma and taste were observed between the various varieties. On a 0‐10 scale, the best varieties had scores of 7‐8, while the poorest scored 2‐4. Evaluation of the overall taste was strongly correlated with ‘fruit aroma’. Sugar, acid and polyphenol contents also played a role in taste. The sugar: acid ratio, rather than total acid or total sugar content, was very important in determining whether a juice was evaluated as very sour or very sweet. A sugar:acid ratio of 15‐16 was judged to give the optimal balance of sweetness‐sourness in the juice.
Reactivation of the cellulose acetate gel bead column used for the removal of limonin from citrus juices
Authors: Johnson Robert L. , Chandler Bruce V.
Published: October 2006

Simple water washes reactivated a cellulose acetate gel bead column after its use to remove the bitter principle limonin from citrus juices on a pilot‐plant scale, preferably after the passage of 10 bed volumes (BV) of juice. Initially, washes with water equal in volume to the treated juice were effective because they removed inhibitors of limonin adsorption but the column would eventually become poisoned. A regime was established for long term operation of the column from the results of monitoring the limonin content and chemical oxygen demand of the wash waters. These results could be fitted to standard mathematical equations for extraction processes and these equations were used, in conjunction with previously developed equations for the adsorption of limonin from citrus juices, to calculate the conditions for the steady‐state operation of the column. A three‐column unit is suggested as a suitable basis for the adsorptive treatment of juice within a continuous processing line. Ten BV of juice would be passed through two of the columns in series at 2.5 BV h−1 reducing the limonin content by about 50‐70% while the third column was being reactivated by the passage of 16 BV of warm water at 3.8 BV. After 4 h−1, the first of the two linked columns would be reactivated and the second would become the first of the new pair of linked columns with the newly reactivated column as the second component.
Storage deterioration in Central African tea: Changes in chemical composition, sensory characteristics and price evaluation
Authors: Cloughley John B.
Published: October 2006

Levels of thearubigins (TR), the high‐molecular‐weight SII TR fraction, and caffeine increased during storage, while flavanols and soluble solids decreased. The theaflavin (TF) content, except for an initial increase during the brief maturation period, decreased as a linear function of time during a 5 month storage period. The loss of FT was the major factor responsible for the deterioration in quality and the reduction in evaluation of black tea. Commercial consignments of tea lost an average of 3.6 FT units and over 12% in price over a transit/storage period of 6 months. Oxidative enzyme activity was retained in the manufactured tea. Peroxidase activity was regenerated continuously throughout the period of study, but residual polyphenol oxidase activity decreased during the latter stages of storage.
Storage deterioration in Central African tea: Methods of reducing the rate of theaflavin degradation
Authors: Cloughley John B.
Published: October 2006

Processes which reduced residual enzyme activity were successful in reducing the rate of loss of theaflavin (TF) during storage. The rate of TF deterioration was also reduced when tea was stored under extreme conditions of low temperature, low moisture and low oxygen availability. Acid treatment of tea during the fermentation stage of manufacture markedly reduced residual enzyme activity and effectively conserved TF levels in commercial consignments of tea.
The effect of fermentation on the biological value of milk proteins evaluated using rats. A study on swedish fermented milk products
Authors: Alm Livia
Published: October 2006

The nutritional quality of non‐fermented and fermented milk products was evaluated using a rat bioassay in two feeding experiments, with casein as the control. Small changes in the biological value (BV) of proteins after fermentation were recorded except in cases of bifidus milk and yoghurt where an increase and a decrease, respectively, in BV were observed. The weight increases in the yoghurt and the bifidus groups were lower than in the other groups. It is concluded that fermentation alters the BV of milk proteins very slightly. Hence, fermented milk products should be acceptable from a nutritional standpoint to administer to malnourished patients.
Digestibility, S‐methyl cysteine sulphoxide content and thiocyanate ion content of cabbages for stockfeeding
Authors: Bradshaw John E. , Borzucki Ronald
Published: October 2006

The dry matter (DM) yields, the digestible organic matter in the dry matter (DOMD) contents and crude protein (CP) contents of the heads of 16 cultivars of cabbage were determined. Cultivars did not differ significantly in DOMD content (mean, 82.9%). DM yield was negatively correlated with DM content (r = − 0.54) and CP content (r= − 0.53). The S‐methyl cysteine sulphoxide (SMCO, the haemolytic factor) and thiocyanate ion (SCN−, a goitrogen) contents of mature heads were determined at four different harvest dates and expressed as a percentage of the DM. There were large harvest date differences for SMCO, the extremes being 1.01 and 1.71 on the first and second harvest dates, respectively. The harvest date differences for SCN− were small with an average content of 0.0471. The cultivar range for SMCO was 0.89–1.68 and for SCN− 0.0263–0.0700.
Volatile components of cooked tubers of the water yam (Dioscorea alata)
Authors: Gramshaw J. W. , Osinowo F. A. O.
Published: October 2006

Volatile constituents were isolated from yams, during cooking, by concurrent steam distillation‐solvent extraction. The essence which resulted was analysed by linked gasliquid chromatography‐mass spectrometry (g.l.c.‐m.s.) employing capillary columns and by gas‐liquid chromatography coupled with sensory evaluation of the column effluent (nasal appraisal). In addition to hydrogen sulphide and a number of high‐boiling fatty acids, 29 compounds, comprising seven hydrocarbons, eight alcohols, eight aldehydes, four ketones, a furan and a disulphide, were identified for the first time in yam. A further five components were tentatively identified by g.l.c.‐m.s. and by thinlayer chromatography of derivatives. 4‐Phenylbutan‐2‐one was the major constituent of the acid‐free essence.
The role of phenols in catalysis of nitrosamine formation
Authors: Walker Ernest A. , Pignatelli Brigitte , Friesen Marlin
Published: October 2006

Phenolic compounds which can potentially form C‐nitroso derivatives by reaction with nitrite can act as catalysts on the formation of an N‐nitrosamine from nitrite and a secondary amine. Using a gas chromatographic technique, this effect has been measured for di‐ and trihydric phenols and for a number of naturally occurring phenolic compounds in the case of N‐nitrosodiethylamine (NDEA) formation. The kinetics for this catalytic effect have been studied in detail with dinitrosoresorcinol and two possible mechanisms have been suggested. In addition, it has been shown that a number of naturally occurring phenols catalyse the formation of NDEA under alkaline conditions and such catalysis can lead to the artifactual formation of nitrosamines during their analysis.
Tannin content of foods commonly consumed in India and its influence on ionisable iron
Authors: Rao Bagepalli S. Narasinga , Prabhavathi Tatineni
Published: October 2006

The tannin content of a number of foods and diets commonly consumed in India has been determined. Most of the tannin in legumes resides in the seed‐coat. Decortication of seeds reduced tannin to a low level with a significant increase in ionisable iron. Germination of the legumes also resulted in a decrease in tannin and an increase in ionisable iron. Diets consumed in different parts of the country had tannin contents ranging from 1.5 to 2.5 g. Much of this appeared to be contributed by spices. A high level of tannin in these foods is associated with low ionisable iron. It is suggested that besides phytates, tannin may be an important factor responsible for the low absorption of iron from habitual diets in India.
Tainting of pork meat by 1,4‐dichlorobenzene
Authors: Watson Arthur , Patterson Ronald L. S.
Published: October 2006

Pork meat rejected by consumers because of a nauseating taint was analysed by gas chromatography and mass spectrometry (g.c.‐m.s.) and found to contain 5–20 mg kg−1 of 1,4‐dichlorobenzene. Trace amounts (10–35 μg kg−1) of 1,4‐dichlorobenzene were found in wood‐shavings used as litter materials and in the feedstuffs, but were considered insufficient to be the main cause of contamination. Meat from the following batch of pigs from the same source contained only very small amounts, similar to those present in normal pork obtained elsewhere (<25 μg kg−1). Examination of data recorded by g.c.‐m.s. in the previous 2 years showed that 1,4‐dichlorobenzene was present in trace quantity (>10μg kg−1) in several samples of normal meat, and appeared to be widespread in its occurrence.
Condensed tannins: A factor limiting the use of cassava forage
Authors: Reed Jess D. , McDowell Rober T. E. , van Soest Peter J. , Horvath Pete R. J.
Published: October 2006

Cassava (Manihot esculenta, Crantz), an important tropical root crop, is considered to have a good potential for use as a forage because leaf blades generally contain <20% crude protein (CP). However, neutral‐detergent fibre (NDF) obtained from cassava leaf blades contains condensed tannins (CTs) and high levels of CP. The amount of CP in the NDF that is insoluble when treated with pepsin or protease is highly correlated with the amount of CTs in the NDF. CTs in the NDF are rich in prodelphinidin. CTs may be an important factor limiting the nutritive value of cassava forage.
Nitrous oxide emission from permanent grass swards
Authors: Webster Colin P. , Dowdell Rodney J.
Published: October 2006

Emissions of nitrous oxide from permanent grass swards growing on monoliths of clay (Salop series) or silt loam (Bromyard series) soils contained in lysimeters (80 cm diameter, 135 cm deep), were measured between October 1977 and August 1980. With no added fertiliser nitrous oxide emissions were small (equivalent to 10–30 μg N m−2 h−1), but after application of nitrate fertiliser (400 kg N ha−1 year−1) during the spring and summer months, emissions increased to peak values ca 1000 μg N m−2 h−1. The peaks were associated with nitrogen applications and rainfall/irrigation events, but persisted only for 3–7 days. Nitrous oxide production in the soil was mostly restricted to the upper 30 cm of the soil profile. Total annual nitrous oxide losses amounted to 6–8 kg N ha−1 from the Salop clay soil and 4–6 kg N ha−1 from the Bromyard silt loam.
Characterisation of wheat flour and gluten proteins using buffers containing sodium dodecyl sulphate
Authors: Bottomley Robin C. , Kearns Helen F. , Schofield J. David
Published: October 2006

The application of buffers containing the anionic detergent sodium dodecyl sulphate (SDS) to the study of wheat flour proteins is described. SDS‐containing buffers are more effective than alternative solvents, including those which contain a cationic detergent, e.g. cetyltrimethylammonium bromide, in terms both of their ability to solubilise wheat proteins and of their suitability as buffers for column chromatography. Thus, a solvent containing 0.069m (2%) SDS solubilises a high proportion (95%) of flour protein, and gel filtration chromatography on columns of Sepharose CL‐4B in the presence of 3.47 × 10−3M (0.1%) SDS, particularly when used in conjunction with polyacrylamide gel electrophoresis, is a powerful tool for the detailed analysis of flour proteins. This technique enables flour proteins to be resolved into three major groups which have been identified as glutenins, gliadins and albumins plus globulins. It can be used to monitor increases in the molecular size of the glutenin fraction during the preparation of gluten from flour, and preliminary data suggests that there may be a correlation between the molecular size of this protein fraction and the breadmaking quality of the flour.
Inorganic and organic arsenic in some commercial east australian crustacea
Authors: Flanjak Johann
Published: October 2006

The levels of inorganic and organic arsenic have been determined in a total of 86 samples of crustacea which included School prawns (Metapenaeus macleayi), King prawns (Penaeus plebejus), Royal Red prawns (Hymenopenaeus sibogae), Eastern Common crayfish (Jasus verreauxii), Blue Swimmer crab (Portunus pelagicus) and Mud crab (Scylla serrata). Most samples were obtained from New South Wales coastal waters and the remainder were purchased at the Sydney fish markets. Inorganic arsenic was isolated by distillation as the chloride and determined by an atomic absorption‐hydride generation method. Organic arsenic was determined on the remaining solution by flame atomic absorption spectrophotometry after digestion of the organic matter with a mixture of nitric, perchloric and sulphuric acids (25 + 5 +1). The Eastern Common crayfish contained the highest levels of inorganic and organic arsenic with ranges of 0.12–0.41 mg kg−1 and 11.9–54.1 mg kg−1 (wet basis), respectively. Of the remaining samples, 85% contained inorganic arsenic at <0.1 mg kg−1 and 97% contained organic arsenic at <7 mg kg−1. The absolute sensitivity and detection limit of the inorganic arsenic method was estimated to be 3 ng (0.03 mg kg−1). For the organic arsenic method the sensitivity and detection limits were estimated as 0.5 and 0.8 mg kg−1, respectively.