bluuebunny/crossref_metadata_2025 huggingface dataset:
The digestion of monosaccharide residues of the cell walls of oat and vetch hays by rumen contents in vitro
Authors: Ben‐Ghedalia Daniel , Rubinstein Aharon
Published: October 2006

The extent and pattern of digestion of oat hay (Avena sativa L.) and vetch hay (Vicia sativa L.) monosaccharides by rumen contents was studied in vitro. The ratios of matrix polysaccharides to lignin were 1.25:1 and 3.82:1 in the vetch and oat hays, respectively. Glucose, xylose and uronic acids were the main sugars in both plants, comprising about 90% of the total monosaccharides. Glucose, xylose and arabinose were mainly confined to the cell walls (CW), whereas galactose and uronic acids were found in high proportions in the soluble fraction. Vetch had a particularly high uronic acid content (14.4 g 100 g−1 DM), of which 71% was pectic material. The ratios of CW‐glucose to CW‐xylose were 2.23:1 and 3.74:1 in the oat CW and vetch CW, respectively. Based on monosaccharide analyses of the CW material, it is suggested that the degree of branching of the matrix polysaccharides is about twice as high in vetch as in oat hay. Total glucose and xylose were more digestible in oat than in vetch hay, whereas most of the minor sugars and the total uronic acids were more digestible in the vetch. Irrespective of species, CW glucose was more digestible than CW xylose. The digestibilities of CW glucose, CW xylose and CW uronic acid were: 61.0, 55.3, 51.5, 34.3 and 62.7, 42.6 for the oat hay and vetch hay, respectively. Following the pattern of digestion, CW arabinose and CW glucose were digested faster than CW xylose and CW uronic acid, irrespective of plant species. The extent of digestion at 12 h of incubation of these sugars was higher in vetch than in oat hay. It is suggeted that the concentration ratio of rapidly to slowly degradable CW sugars, in a given plant, is a major determinant of the rate of CW digestion by rumen microorganisms.
Lenticel blotch pit, watercore, splitting and cracking in relation to calcium concentration in the apple fruit
Authors: Perring Michael A.
Published: October 2006

Analyses of apples, of various varieties and from many sources, affected by lenticel blotch pit and/or watercore showed that calcium concentrations in the fruit were usually extremely low. The severity of lenticel blotch pit, either on the tree or during storage, increased with decreasing concentrations of calcium and/or increasing concentrations of potassium. Split and cracked apples had lower concentrations of calcium or higher concentrations of potassium than sound fruit from the same sources. The disorders usually occurred when mean concentrations of calcium in bulked random samples of fruit fell below 4 mg 100 g−1 fresh wt and lenticel spotting was noted on apples with concentrations at this level. Incidences of these disorders in the orchard therefore indicate that the fruit is likely to develop bitter pit and breakdown during storage.
The effect of harvest date on the yield and composition of Tasmanian dill oil (Anethum graveolens L.)
Authors: Clark Robert J. , Menary Robert C.
Published: October 2006

Semi‐commercial plots of dill (Anethum graveolens L.) were established in the Derwent Valley area of Tasmania during 1981 and 1982. The 1981 crop was irrigated and yielded 43 to 104 kg ha−1 of dill herb oil (less than 35% carvone) or 57 to 73 kg of dill seed oil ha−1, depending on harvest date. The non‐irrigated crop established in 1982 yielded 41 to 77 kg of dill herb oil. The carvone content of oil from the 1982 crop failed to reach a level of 35%, the minimum considered characteristic of dill seed oil. These results indicate that Tasmania is well suited to the production of either dill herb or seed oil and that higher yields of oil and carvone are obtained per hectare from the herb crop. Major components of Tasmanian dill oil were carvone (9.6 to 46.5%), α‐phellandrene (15.5 to 49.1%), β‐phellandrene (5.2 to 7.6%), limonene (16.5 to 22.3%) and dimethylhexahydrobenzofuran (0.4 to 11.9%).
Studies on Thearubigin Pigments in Black Tea Manufacturing Systems
Authors: Hazarika Mridul , Chakravarty Sukhomoy K. , Mahanta Pradip K.
Published: October 2006

The formation of thearubigin pigments in prevalent commercial manufacturing systems such as orthodox roll, roll followed by curling, tearing, crushing (CTC), rotorvane combined with CTC and CTC alone was studied in the six Tocklai released clones TV‐1, TV‐2, TV‐8, TV‐9, TV‐17 and TV‐18. The contribution of the pigment composition, especially thearubigins of high, intermediate and low molecular weights as separated by a Sephadex LH 20 column, was examined on the basis of the types of leaves, degree of wither and roll, conditions of fermentation and the temperature and type of drying. It was apparent that the biochemical pathway in the black tea processing could be conveniently followed from the thearubigin formation. Further, the amount of high molecular weight thearubigin could determine the quantity of cream formed in a black tea brew. The thearubigin and concomitant pigments such as theaflavin have distinct organoleptic properties and their variation was reflected in the overall quality of the finished product.
Changes in the nutritional value of pearl millet flour during storage
Authors: Chaudhary Pinky , Kapoor Amin C.
Published: October 2006

The whole grain flour of three varieties of pearl millet (Pennisetum typhoides Rich) became rancid on days 6, 7, 8 and 10, and inedible on days 11, 12, 13 and 14 of storage in gunny sacks, earthen pots, tin cans and polythene bags, respectively. The moisture, sugar, free fatty acids, fat acidity and peroxide levels increased, and those of α‐tocopherol and β‐carotene decreased during storage. The concentrations of protein, ash, crude fibre and phospholipids were not affected. Flour stored in polythene bags was least affected and that stored in gunny sacks was most affected by storage conditions.
Field estimation of ammonia volatilisation from 15N‐labelled urea fertiliser
Authors: Alan Rodgers G. , Pruden Gordon
Published: October 2006

Granules of 15N‐labelled urea (150 kg N ha−1), with or without the urease inhibitor hydroquinone, were broadcast on to small plots of winter oilseed rape in March. Ammonia volatilisation losses were estimated by a 15N balance procedure in which the amount of 15N in the plants, plus that in the soil to 70 cm depth, was determined 18 days after urea application. All the urea‐N was recovered in soil and plants from plots given either urea alone or urea plus hydroquinone; hence there was no volatilisation of ammonia. Although the soil pH was high enough (7.7 to 8.0) for ammonia loss, this did not occur because the soil was too cold, too wet and had a high cation exchange capacity.
The conditioning of wheat. The influence of conditioning temperature on flour yield, moisture content and colour
Authors: Robinson Ian M. , Dockerty John F. , Fearn Thomas
Published: October 2006

Two UK wheats of similar protein content but differing in hardness have been conditioned at temperatures of 4, 10.5, 19 and 28°C to a moisture content of 15.5%, using lying times in the range 2 to 24h. The milling performance of the wheats has been assessed in terms of flour yield, moisture content and grade colour figure (GCF). Flour yield was expressed as straight‐run milling yield (SR) and also as total yield (TE) which included flour from the impact finishing of by‐products. The use of a conditioning temperature of 28°C increased TE and SR for the hard wheat and TE for the soft wheat, but decreased SR for the latter. Both types showed a reduction in flour yield when a lying time of 2h was employed. The use of temperatures above or below 19°C led to improved GCF results. The combination of low temperatures and short lying times brought about reductions in flour moisture content but these reductions were shown to be only partially responsible for the accompanying decreases in flour yield.
Comparison of an alkaline picrate and a pyridine‐pyrazolone method for the determination of hydrogen cyanide in cassava and in its products
Authors: Izomkun‐Etiobhio Benjamin O. , Ugochukwu Emmanuel N.
Published: October 2006

A determination of hydrogen cyanide in fresh cassava tissues and in processed cassava products using an alkaline picrate procedure and a pyridine‐pyrazolone method which uses Conway vessels has been made. Results obtained for the fresh cassava tissues by the two methods were similar. Statistically significant higher values for processed cassava products were obtained by the alkaline picrate method which measured both glycosidic and non‐glycosidic cyanide. The suggestion is reaffirmed that hydrogen cyanide in processed cassava products may exist in two forms: glycosidic and non‐glycosidic (entrapped) cyanide.
Extraction of protein and solids from wheat bran
Authors: Roberts Peter J. , Simmonds David H. , Wootton Michael , Wrigley Colin W.
Published: October 2006

The influence of pH, time, temperature, cellulase treatment and washing conditions on the recovery of solids and protein from Australian wheat bran was investigated. Highest yields (83% of available protein, 72% of total solids) were achieved by extracting at pH 12 and washing with water at pH 7. However, acceptable yields could be obtained under near neutral conditions by extracting at pH 6.5 for 16 h followed by three washes at pH7. Under these conditions 72% of the protein and 55% of the total solids were extracted and greater stability of the vitamins thiamin, riboflavin and pyridoxine was expected. The use of cellulase in an attempt to disrupt the aleurone cell walls did not improve the recoveries of either protein or solids.
The effect of straw incorporation on the uptake of nitrogen by winter wheat
Authors: Powlson David S. , Jenkinson David S. , Pruden Gordon , Johnston A. Edward
Published: October 2006

There was a small decrease in grain yield (from 10.8 to 10.5 t ha−1) when wheat straw (3 t dry matter ha−1) was incorporated into a silty clay loam soil sown to winter wheat. In the absence of straw, 60% of autumn‐applied 15N‐labelled nitrate was lost from the crop:soil system. Straw incorporation decreased this loss to 47%. There was little overall effect on the uptake of N by the crop, presumably because straw immobilised inorganic N that would otherwise have been leached from the soil during winter. Only 12% of the N in 15N‐labelled straw was recovered by the crop; 78% still remained in the soil one year after incorporation.
Distribution of diethylstilboestrol in pigs
Authors: Bates Michael L. , Warwick Michael J. , Shearer George , Harwood David J. , Herriman Ira D. , Heitzman Raymond J. , Watson David H.
Published: October 2006

The synthetic growth promoter diethylstilboestrol (DES) administered orally to pigs can be detected by radioimmunoassay (RIA) analysis of kidney, liver, faeces, bile and urine from animals fed continuously to slaughter, but not in muscle, fat or plasma. If treated animals are fed on material not containing DES for 72 h prior to slaughter, then the levels of parent compound and metabolite in all products decrease to become not significantly greater than those in control animals. The gross metabolism of DES in pigs and bovines appears to be similar.
Dietary fibre fractions in cereal and cereal‐containing products in Britain
Authors: Wenlock Robert W. , Sivell Lorna M. , Agater Irena B.
Published: October 2006

The values for dietary fibre in the current UK food tables were obtained using a fractionation method which involved digestion of starch with a takadiastase preparation. For the revision of the food tables new values for the dietary fibre in cereal and cereal‐containing meat products were obtained by an improved fractionation method which used a mixture of amyloglucosidase and α‐amylase to digest starch. The full details of this analytical method are given, along with the fibre components which were found in 138 cereal‐containing foods. This method produced higher values than the previous method in most processed cereal products. Also the levels of pentoses in the non‐cellulosic polysaccharide fraction and of lignin residues are greater. The study considerably extends the range of cereal‐containing foods for which the amount of dietary fibre and its components has been determined.
Automated determination of total sugars in sugar crops grown for energy
Authors: Gaines T. Powell , Gascho Gary J.
Published: October 2006

A fast, accurate method for determining total sugars in sugar crops was developed. Sugars were quantitatively removed from the tissue by homogenisation and hot water extraction. Lead acetate was used to clarify the extract by precipitating any interfering non‐sugar reducing substances. Lead was then removed by precipitation with sodium oxalate. The extract was hydrolysed to convert sucrose into glucose and fructose. After neutralising, total sugars were determined as total reducing sugars by automated colorimetry using a Technicon Auto‐Analyzer. Data presented show optimum conditions for extraction, clarification and acid hydrolysis of sucrose to reducing sugars. The method has a precision of 2.1% coefficient of variation for 10 consecutive analyses of a sweet sorghum sample with a mean total sugar concentration of 14.2±0.3%.
α3‐gliadin from Timmo wheat. Isolation and partial structure determination
Authors: Thiang Lek C. , Waldron Norman M. , Ohannesian Arpie D.
Published: October 2006

Ion‐exchange chromatography, followed by gel‐filtration has been used to separate α3‐gliadin from the hard English wheat, Timmo. Amino acid sequence determination on the protein has revealed 10 N‐terminal residues and six C‐terminal residues. The gliadin has been cleaved by N‐bromosuccinimide into two peptides and another two peptides have been obtained by treatment with cyanogen bromide. The amino acid analyses of the peptides and α3gliadin are reported.
Effect of mild autoclaving and deamidisation on the nutritive value of protein fractions
Authors: Goulet Gilles , Amiot Jean , Simard Clovis , Delisle Jocelyne , Brisson Germain J.
Published: October 2006

The nutritive value of zein, rapeseed 12S and α‐casein was assessed by apparent digestibility coefficient (ADC) and net protein ratio (NPR). Protein fractions were suspended (100 g litre−1) in 0.1M HCl or in water and autoclaved for 1 h. The degree of deamidisation following acid autoclaving was 14.0% for zein, 7.3% for rapeseed 12S and 8.9% for α‐casein. Results indicate that autoclaving in water or in HCl improved the ADC of zein and rapeseed 12S. However, acid autoclaving increased (P<0.05) the NPR of rapeseed 12S (from 3.07 to 3.44) whereas it decreased (P<0.05) that of α‐casein (from 4.21 to 3.57).
Measurement of sunflower seed respiration rates and quotients by gas‐solid chromatography in a closed system
Authors: Chapman Glenn W.
Published: October 2006

Sunflower seed respiration rates and respiratory quotients (RQ) were measured by gas‐solid chromatography coupled to a closed system which contained the seed sample. By using a gas sampling valve fitted with a 0.5 ml sample loop, head‐space sampling is eliminated. The system is reliable, reproducible, and the data can be obtained in short time periods, as O2 and CO2 can be measured simultaneously. With this procedure, a 10°C increase in temperature produced about a two‐fold increase in respiration rates (μlCO2h−1g−1 DM) in seed samples at the same moisture level (13%); while a three‐fold increase in seed moisture (7% vs 20%) produced a 148‐fold increase in respiration rates at 42°C. High RQ values indicated that high temperatures and low seed moisture may have limited O2 uptake by sunflower seed. Under other conditions, the seed respired aerobically and used carbohydrates as an energy source (RQ=1). Germination test indicated that exposure of sunflower seed to very low O2 and high CO2 levels for 24 h did not adversely affect seed viability. This procedure was successfully applied to obtaining respiration data for soya beans and fescue grass seed.
Composition of Cicer soongaricum seeds
Authors: Katiyar Santosh K. , Bhatia Ashok K. , Kumar Narinder , Atal Chand K.
Published: October 2006

The legume, Cicer soongaricum grows wild in high altitude regions of the Himalayas. The seeds are nutritionally rich, containing 19.1% protein, 44.5% starch, 7.2% oil and 3.4% minerals. Glutelin has been found to be the major protein fraction (43.7%) whereas albumin, globulin and prolamin are 11.5, 14.3 and 6.6%, respectively. The oil contains 29.8% phospholipids, wherein palmitic (30.0%), stearic (32.4%) and linolenic acids (13.6%) are the major fatty acids. The phospholipid fraction has an appreciable content of phosphatidyl choline (1.0% in the seed) which is higher than in soya bean, presently the commercial source of its manufacture.
Effect of gamma radiation on ochratoxin production by the fungus Aspergillus ochraceus
Authors: Paster Nachman , Barkai‐Golan Rivka , Padova Reuven
Published: October 2006

Mycelial discs of the fungus Aspergillus ochraceus NRRL 3174 were exposed to gamma irradiation and then incubated on synthetic medium (SM). Growth rate, mycelial dry weight and ochratoxin production were measured. A delay in mycelial growth of 24 and 48h over the control occurred following irradiation of mycelial discs with 150 and 200 krad, respectively. No growth occurred from discs exposed to 300 krad. An increase in ochratoxin production occurred on the SM from cultures developing from discs of mycelium which had been irradiated with 50, 100, 150 and 200 krad. The amount of toxin produced was 3500, 4100, 3200 and 3000 ng per plate, respectively, as compared with 2800 ng per plate produced by the control. Exposure of mycelial discs to a temperature of 40°C for 15 and 30 min prior to treatment with 200 krad resulted in complete inhibition in mycelial growth. No growth inhibition or notable change in ochratoxin production was recorded when the mycelial discs were exposed to 25, 50 or 100 krad after the heat treatments. Pure ochratoxin was found to be stable even at 7.5 mrad, and no reduction in its fluorescence intensity under u. v. light was recorded following that dose.
Some studies on the effect of maturity and storage on the chlorophyll content and essential oils of the cardamon fruit (Elettaria cardamomum)
Authors: Kumara Subaddarage J. Sarath , Packiyasothy E. Vellupillai , Jansz Errol R.
Published: October 2006

Cardamom (Elettaria cardamomum Maton) is generally harvested immature in Sri Lanka. The effect of maturity on the appearance of the capsule (including chlorophyll content), essential oil content and composition is reported here. With increase in maturity all the above parameters were altered. The notable changes were increased volatile oil and chlorophyll content. The main effect on volatile oils composition was an increase in 1,8 cineole content and a decrease in α‐terpinyl acetate content. A preliminary study on storage showed that neither oil content nor composition varied significantly and that on controlling moisture content chlorophyll losses were retarded.
Nitrogen extraction from defatted rapeseed, with particular reference to United Kingdom commercial rapeseed meal
Authors: Finnigan Timothy J. A. , Lewis Michael J.
Published: October 2006

Nitrogen extraction profiles of rapeseed (RS), post‐press cake (PP) and commercial rapeseed meal (RSM), drawn from the same batch, were evaluated; the RS and PP being defatted in the laboratory prior to extraction. The RSM exhibited lower nitrogen extractability, with the profiles less sharply defined, at different conditions of pH and ionic environment than for RS or PP. This was attributed to the heat treatment received at the end of the process during the toasting‐desolventisation. The nitrogen extractability of RSM was further investigated using double extraction techniques with different solvents (NaCl, CaCl2 and water), over a wide range of pH. None of the extraction regimes studied suggested improved practical possibilities for meal protein extraction, compared with single aqueous extraction at high pH. Meal protein extracts however, were found to be comparatively high in crude protein when expressed on a solids basis, a fact which suggests the possibility for additional concentration by ultrafiltration.
Analysis of sugars and organic acids in ripening mango fruits (Mangifera indica L. var Keitt) by high performance liquid chromatography
Authors: Medlicott Andrew P. , Thompson Anthony K.
Published: October 2006

The sugars and organic acids present in the pulp of Keitt mangoes at various stages of ripeness were analysed by h.p.l.c. Ripening was associated with a loss in firmness, peel chlorophyll and pulp acidity, with increasing soluble solids and total sugars. The major sugars were identified as glucose, fructose and sucrose. All three increased during ripening; sucrose was found to be in the greatest concentration throughout, with fructose the predominant reducing sugar. Acidity loss was shown by decreasing titratable acidity and increasing pH values. Citric and malic acids were found to be the major organic acids. A large decrease in citric acid and a small reduction in malic acid were responsible for the loss of acidity. Tartaric, ascorbic, oxalic and α‐ketoglutaric acids were also shown to be present at low concentrations.
Determination of ethanol, volatile fatty acids, lactic and succinic acids in fermentation liquids by gas chromatography
Authors: Playne Martin J.
Published: October 2006

A rapid and simple quantitative method was developed to determine, by gas chromatography, the concentrations in fermentation liquids of ethanol, the C2‐C6 volatile fatty acids, and lactic and succinic acids. Aqueous samples were acidified with 250μlml−1 metaphosphoric acid (5:1 ratio), centrifuged, and injected directly on to a column containing a porous aromatic polymer (Chromosorb 101) maintained at 200°C in a gas chromatograph fitted with a flame ionisation detector. It was unnecessary to purify samples further before injection, although distillation and ion‐exchange methods were examined. Derivatisation of lactic and succinic acids before injection was not necessary, but the lowest level of detection of these two relatively non‐volatile acids was about four times greater than that for the volatile fatty acids. The method described was suitable for the analysis of rumen fluid, methane digester fluid, silage extracts and other anaerobic fermentation fluids. The relative retention times are given for 23 organic acids and six other fermentation end‐products.
Biscuit making properties of flours from hard and soft milling single variety wheats
Authors: Wainwright Andrew R. , Cowley K. Martin , Wade Peter
Published: October 2006

Bench scale baking tests for two types of biscuits,1 a hard sweet (HS) and a short sweet (SS), have been used to examine the biscuit making properties of a large number of flour samples from wheats grown in four consecutive years (1980–1983). Multiple regression models for prediction of biscuit properties using a range of standard cereal laboratory tests as independent variables on results from 1980–1981 harvest wheats confirmed earlier observations that such tests are of limited commercial value for biscuit flour specification. However the results of baking tests, with both types of biscuit, from single wheat varieties grown during 1981–1983 showed that flours from soft milling wheats (SMW) required less water to give biscuit doughs of standard consistency (measured instrumentally) than did flours from hard milling wheats (HMW). In addition biscuit doughs made with SMW flours gave greater oven spring, i.e. biscuits of lower bulk density, than doughs made from HMW flours. In each season the difference in the mean values of both parameters for flours milled from SMW and HMW was highly significant (P<0.001). With one exception the variability of the measured parameters within seasons was not significantly different between SMW and HMW. However within both SMW and HMW varieties highly significant differences (P<0.001) were observed between seasons for the mean values of both measured biscuit parameters. The effect of flour particle size on the biscuits was studied by regrinding a number of flours. With flours from both SMW and HMW reduction in particle size resulted in HS biscuits of higher density but SS biscuits of lower density.
Dissimilarity scaling and INDSCAL analysis in the study of flavour differences between normal pHu and DFD beef
Authors: Francombe Mariko A. , Macfie Halliday J. H.
Published: October 2006

Overall dissimilarity measurement of paired stimuli followed by Individual Differences Scaling (INDSCAL) analysis was used to study flavour perception in a set of beef extracts. The experiment was designed to determine whether pH contributed to flavour difference between beef of “normal” ultimate pH (pHu5.8) and “dark‐cutting” (DFD) beef (pHu6.2). Assessors distinguished the flavour of “normal” pHu and DFD beef both by a combination of pH and titratable acidity, and a second dimension independent of pH. The chemicals added to adjust pH independently of the original muscle composition contributed a third flavour dimension. Substantial assessor variation was observed in the relative weight given to the three flavour dimensions, and this is discussed in relation to the task of judging overall dissimilarity.
Evaluation of a system of wind tunnels for field studies of ammonia loss from grassland through volatilisation
Authors: Ryden John C. , Lockyer David R.
Published: October 2006

Rates of ammonia (NH3) loss from a ryegrass sward measured using a system of small wind tunnels were compared with concurrent measurements made using a micrometeorological mass balance method. Measurements were made during two experiments within a circular plot (radius 10m) treated with urea at a rate of 200kgNha−1. In the first experiment, air speed through the tunnels was adjusted as necessary to maintain a value of approximately 1ms−1. This value differed on most occasions from the mean ambient wind speed which was measured at a height of 250mm and which ranged from 0.61 to 2.95ms−1. Rates of loss measured using the wind tunnels differed by a factor of between two and five from those measured using the mass balance method; there was no consistent pattern in the differences between the rates of loss. The total losses of NH3measured during 15 days were equivalent to 49.1 and 30.2kg Nha−1for the mass balance and wind tunnel methods, respectively. In the second experiment, air speed through the tunnels was adjusted as necessary to maintain a value as close as possible to the mean ambient wind speed measured at a height of 250mm. Rates of NH3loss measured using the two methods did not differ significantly; total losses of NH3during 17 days were equivalent to 96.9 and 101kg Nha−1for the mass balance and wind tunnel methods, respectively. The difference between the findings of the two experiments could be attributed to the direct effect of air speed through the tunnels rather than to differences between ambient temperatures and those inside the tunnels. During and following periods of rain the rates of loss measured using the tunnels were up to six times greater than those observed with the mass balance method. Rates of loss measured by the two methods became similar again when the tunnels were moved following rain. The study demonstrates that enclosures can be designed and operated to provide reliable measurements of the rate of NH3loss from grassland. Potential applications of the two methods are discussed.
A micromethod for the differentiation of fresh from frozen fish muscle
Authors: Salfi Vincenzo , Fucetola Francesco , Pannunzio Giovanna
Published: October 2006

A sensitive and rapid routine method was developed which allows a general, unambiguous and reliable differentiation between fresh and frozen‐thawed fish muscle. The suggested procedure consists of (i) mild extraction of muscle in isotonic and buffered medium, (ii) rapid separation of the marker isozymes—those of the mitochondrial aspartate aminotransferase—by cellulose acetate electrophoresis, (iii) specific staining at neutral pH for enzyme activity by sandwich with an agarose‐substrate‐chromogen pad, and (iv) a clearing and drying process to make a permanent record.
Hydrolysis of the toxic constituents (vicine and convicine) in fababean (Vicia faba L.) food preparations following treatment with β‐glucosidase
Authors: Arbid Mahmoud S. S. , Marquardt Ronald R.
Published: October 2006

Several experiments were carried out to determine whether the concentrations of vicine and convicine in fababean food preparations were reduced following heat and β‐glucosidase treatment. Heating fababeans to relatively high temperatures was not effective in reducing the concentration of these glycosides. Treatment of cooked fababeans (fababean paste) with ground raw almond powder, which is a rich source of β‐glucosidase (EC 3.2.1.21) activity, resulted in the hydrolysis of vicine and convicine. The degree of hydrolysis ranged from partial to complete and was dependent on the duration of the treatment period (1 to 24 h), the temperature at which treatment was carried out (1 to 30°C), the pH (6.4 to 4.6) as adjusted by the addition of lemon juice and the amount of ground almonds added to the fababean paste. For example, 88 to 89% of the glycosides were hydrolysed when 1 g of fababean paste was mixed with 0.1 g of almond powder and 0.1 ml of lemon juice and incubated at 30°C for 3 h. This study demonstrated that the concentration of vicine and convicine and their corresponding aglycones can be greatly reduced in fababean food preparations by enzymic hydrolysis.
Analysis of pea lipid content by gas chromatographic and microgravimetric methods. genotype variation in lipid content and fatty acid composition
Authors: Coxon David T. , Wright David J.
Published: October 2006

Two methods were developed for the analysis of total lipid content in dried peas. The first measured total fatty acid methyl esters (total FAME) by gas chromatography. The second was a microgravimetric method. Both methods gave equally precise results with a skilled analyst but the total FAME method required less sample, was easier to use and was preferred for the analysis of large numbers of samples. Using the total FAME method a wide range of pea genotypes including primitive or wild forms, field peas, and round and wrinkled garden peas were analysed. The lipid content, expressed as percentage by weight, of dry whole pea flours prepared from 166 genotypes ranged from 1.4–4.0% and exhibited a bimodal distribution. The lower lipid population corresponded to round peas and the higher lipid population to wrinkled peas. Although only five fatty acids occurred in significant quantities in the total lipid there was considerable variation in their individual contents. In decreasing order of content, in the vast majority of genotypes, the fatty acids were linoleic (18:2), oleic (18:1), palmitic (16:0), linolenic (18:3) and stearic (18:0). In a few genotypes, however, oleic acid predominated over linoleic acid. Linolenic acid ranged from 2.5–14.9% of the total fatty acids. A positive linear correlation (r=0.98) was found to exist between total FAME values (LF) and corresponding gravimetric lipid values (LG) for a combined population of round and wrinkled peas. An initial calibration was derived by regression analysis of data obtained by the FAME method and a large scale gravimetric method. This was tested and found to give satisfactory prediction of LG on a second set of samples analysed by the FAME method and the microgravimetric method.
Further studies on skull shape in relation to carcass fatness in pigs
Authors: Whelehan Oliver P. , Gregory Neville G.
Published: October 2006

The relationships between skull shape and carcass fatness were examined in 27 pigs from a genetic selection study using 16 linear skull measurements, ten measurements of carcass fat weight and six measurements of backfat thickness. The most variable index of skull shape was derived by principal components analysis and contrasted long and narrow skulls with short and broad ones. Correlations showed that short broad skulled pigs tended to be leaner than long narrow skulled pigs confirming an earlier study. Genetic selection for improved production performance led to divergence in skull shape between the selected and control lines. The use of skull shape in assessing carcass composition is discussed.
Quantitative gas‐liquid chromatography of amino acids in enzymic hydrolysates of food proteins
Authors: Ihekoronye A. I.
Published: October 2006

A method is described for analysing amino acids released from food proteins by the combined but sequential action of papain and pronase E. Amino acids liberated in this way were analysed by gas‐liquid chromatography (g.l.c.) as their N‐trifluoroacetyl n‐butyl esters. Prior to proteolysis, presolubilisation of the proteins was achieved in 0.05MHCl. Of over 30 different food proteins analysed, more than 90% of the total nitrogen was recovered, showing that the process achieved virtually complete enzymic hydrolysis with little destruction of amino acids. The amino acid data obtained by g.l.c. analysis of enzymic hydrolysates were compared to those of cation‐exchange (CIE) analysis and to profiles obtained from acid, performic acid and alkaline hydrolytic procedures. Intraclass repeatability analysis was used to test reproducibility of each amino acid value within the three procedures used to obtain the profile. Although individual amino acid values differed somewhat, on the whole, there was good agreement (r=0.742) between values from g.l.c., CIE analysis of enzymic hydrolysates and CIE analysis of acid, performic acid and alkaline hydrolysates.
The distribution of calcium in apples with senescent breakdown
Authors: Perring Michael A. , Pearson Keith , Martin Kenneth J.
Published: October 2006

The transverse distribution of calcium across median slices was measured in Cox's Orange Pippin apples with breakdown and in sound fruit from the same sources removed at the same time from stores held at 3°C. In addition to usually having a lower average calcium concentration in the slice, every apple with breakdown had a lower proportion of calcium in the core zone than the average proportion for the sound fruit.
Biotechnology and the rumen: A mini review
Authors: Armstrong David G. , Gilbert Harry J.
Published: October 2006

The review discusses the potential use of recombinant DNA technology to modify fermentation characteristics of rumen microorganisms with the objective of improving efficiency of meat, milk or wool production by ruminant livestock. Some of the genetic modification postulated are enhanced cellulolysis, reduced methanogenesis and decreased proteolysis/deamination. The technical difficulties involved in carrying out the gene modifications in terms of vector construction, uptake of DNA and expression of heterologous genes are discussed. Finally, the feasibility of introducing a genetically altered microorganism into a complex symbiotic ecosystem is questioned.
Yield and quality of essential oil from Pelargonium graveolens cultivated in israel
Authors: Fleisher Alexander , Fleisher Zhenia
Published: October 2006

Pelargonium graveolens was cultivated to evaluate the potential for geranium oil production in Israel. During the summer (April‐November) the essential oil content in fresh plants increased from 0.2‐0.4%. In this period a Pelargonium crop can be harvested three times. A total yield of 185 litres ha−1 of geranium oil can be expected, including the essential oil dispersed and remaining in the distillation water. This so‐called ‘secondary’ oil can amount to 25% of the total oil yield. The odour evaluation and composition data show that oil from P. graveolens grown experimentally in Israel is of good quality and belongs to the African type of geranium oil.
Effect of protease inhibitors from Adenanthera pavonia on the biochemical and microbiological quality of fishes
Authors: Veerappa Gowda H. S. , Karunasagar Iddya
Published: October 2006

Fishes were given dip treatment in protease inhibitors extracted from Indian red wood seeds (Adenanthera pavonia) and their microbiological and biochemical characters were examined during storage at refrigerator temperatures. The results suggest that protease inhibitors bring about qualitative and quantitative changes in the microflora. Production of trimethylamine (TMA) and volatile bases appeared to be suppressed in the treated fishes. Incorporation of protease inhibitors in broth suppressed such activities as reduction of trimethylamine oxide, production of H2 S and hydrolysis of gelatin in a significant proportion of bacterial cultures.
Qualitative and quantitative analysis of petitgrain Eureka lemon essential oil by fused silica capillary column gas chromatography mass spectrometry
Authors: Baaliouamer Aoumeur , Meklati Brahim Y. , Fraisse Daniel , Scharff Claude
Published: October 2006

The identification of Algerian petitgrain Eureka lemon essential oil was carried out by gas liquid chromatography‐mass spectrometry in electronic impact mode using a fused silica capillary column (FFAP). The results enabled a previous study on this oil to be completed where the relative retention data and chemical derivation reactions had been performed. A preparative gas chromatography was applied to give a better g.c.‐m.s.analysis of minor compounds; thus, two new products (citronellyl n‐propionate and cedrol) were revealed by this method. Only 80 compounds were identified after indexation of 137 mass spectra and after comparison with those in the literature because most mass spectra data banks are not well adapted for the identification of essential oils. A global comparison of the percentage composition of the major compounds of this oil with those in other petitgrain lemon essential oils has revealed distinct differences. From the mass spectra of nine monoterpenic hydrocarbons, it was shown that comparison of the intensity ratio of the characteristic fragment ions in EI mode, which has been suggested by some authors as a general method of identification of compounds with similar mass spectra, is not reliable.
Factors affecting the yield of milk and its constituents, particularly fatty acids, when dairy cows consume diets containing added fat
Authors: Clapperton John L. , Banks William
Published: October 2006

Lactating cows and heifers were offered diets containing (a) no added oil, (b) added tallow and (c) an added mixture of palm oil and soya oil. Each of these diets was given at two levels of feeding. The diet containing no added oil at the high level of feeding was isoenergetic and isonitrogenous with diets (b) and (c) at the low level of feeding. This design allowed the effect of the decrease in fermentable substrate (consequent upon substituting fat for starch) on the output of short‐chain fatty acids (SCFA) in the milk fat to be quantified. Approximately 20% of the total decrease in the concentations of these acids in milk was found to be due to the loss of dietary starch when tallow was fed, the value being somewhat higher in the case of the more unsaturated acids of diet (c). These results are considered in the context of the established changes in citrate concentration of milk that occur on feeding fat. It is concluded that the major cause of decreased output of SCFA in the milk when dairy cows consume rations containing added fat is mediated within the mammary gland and is probably due to the dietary long‐chain fatty acids acting as partial inhibitors of the synthesis of the SCFA.
Subtilisin inhibitors from legume seeds: A purification procedure
Authors: Tovar Juscelino , Lorenzo Pilar , Seidl Dinah S.
Published: October 2006

Subtilisin inhibitors were prepared from ethanol‐acetone precipitated seed extracts of chick peas, jack beans and broad beans, heated to destroy endogenous proteases. Trypsin inhibitors were complexed with trypsin and separated from subtilisin inhibitors by molecular sieve chromatography. The eluates were again heated to avoid tryptic degradation. The procedure was easy to handle and gave satisfactory yields. In a final step two subtilisin isoinhibitors from chick peas were purified to electrophoretic homogeneity. They constitute 0.01% of the defatted dry weight.
Kinetics and equilibria of tea infusion: Theaflavin and caffeine concentrations and partition constants in several whole teas and sieved fractions
Authors: Price William E. , Spiro Michael
Published: October 2006

Concentrations of theaflavin and caffeine were determined in whole Kapchorua Pekoe Fannings and in six of its sieved fractions, as well as in Kapchorua Pekoe Dust, Betjan Flowery Broken Orange Pekoe and Rupai Flowery Orange Fannings and in one sieved fraction of each. The partition constants of theaflavin and caffeine between these leaves and water at 80°C were also determined. Neither property varied significantly with leaf size but did depend on leaf origin and manufacture. The concentration and partition constants for caffeine were greater than for theaflavin. As a corollary, the ratio of caffeine to theaflavin is larger in tea initially drawn from the teapot than in the beverage prepared after topping up with fresh hot water.
The nitrogen content of potato (Solanum tuberosum L.) tubers in relation to nitrogen application—the effect on amino acid composition and yields
Authors: Millard Peter
Published: October 2006

The effect of nitrogen application on the nitrogen content and yield of amino acids from potato tubers was studied in one experiment in 1983 and two in 1984. Increasing fertiliser N over the range 0–250 kg ha−1 raised tuber nitrogen concentrations from 0.68–0.81 to 1.27–1.49% DM. Applying half the fertiliser on the seedbed and half at tuber initiation did not increase tuber nitrogen concentrations compared with a single broadcast application at planting. Increasing tuber nitrogen concentrations had little effect upon the proportion recovered in amides or the different amino acids. Yields of some nutritionally essential amino acids were, therefore, substantially increased up to a maximum of 256 kg ha−1 in 1982 and 308 and 384 kg ha−1 in 1984 at the highest fertiliser level. These yields were significantly higher (P<0.01) than those found with the nitrogen application rate optimal for tuber dry matter production (213, 195 and 331 kg N ha−1, respectively) in the same experiments. Methionine and cystine were the limiting essential amino acids. As the amount of each amino acid contained in a unit weight of fresh tuber increased with nitrogen supply, application of more nitrogen than is needed for maximal tuber dry matter production increased protein yields without decreasing the nutritional quality.
Effect of duration of liquefaction on viscosity and polyphenol content of the mash and subsequent glucose recovery in bird‐proof sorghum
Authors: Kock Johan L. F. , Groenewald Estienne G. , Krüger Gert H. J. , Lategan Pieter M.
Published: October 2006

An increase in the period of sorghum starch liquefaction (amylolytic period) resulted in a sharp increase in mash viscosity and a drastic drop in glucose recovery. The highest recovery (84%) was obtained with a liquefaction period of 5 min. The progress of the hydrolysis process was recorded by monitoring the change in sugar composition by means of h.p.l.c. The polyphenol content of the mash remained almost constant during the optimum hydrolysis process.
Near infrared reflectance analysis of oil concentration in an emulsion: A study of oil and water migrations in a mayonnaise‐based salad
Authors: Davies Anthony M. C. , Brocklehurst Timothy F.
Published: October 2006

Equations were derived for estimating the oil concentration in mayonnaise containing 11–75% (w/w) oil in mayonnaise‐based salads by measurements of absorption using a near infrared scanning spectrometer (Neotec 6350 Research Composition Analyzer). The precision of the predictions averaged from two or three equations was better than ±1.0% at an oil concentration of 40% (w/w). The use of the method is demonstrated by its application to a study of the migration of oil and water in coleslaw during the first 6h after production.
Comparison of techniques for chromium sesquioxide analysis in marker studies
Authors: Lee Julian , Fisher Murray T. , Maré Beatrice
Published: October 2006

Titrimetric, atomic absorption and plasma emission spectrometry methods are compared in the estimation of chromium from an alkaline fusion solubilisation of chromium sesquioxide (Cr2O3) digestibility marker in rat faeces. Considerable differences in the between‐batch precision for the methods were noted. The ferrous ammonium sulphate titration showed the least imprecision (0.67% RSD) compared with 2.1% RSD for the inductively coupled plasma emission spectrometry and 4.7% RSD and 5% RSD for the atomic absorption methods of the nitrous oxide‐acetylene and air‐acetylene flames respectively. The atomic absorption methods were found to be highly sensitive to interferents, chromium oxidation state and changes in flame chemistry with respect to operating conditions.
Measurement of fat and moisture in air‐dried bread by near infrared reflectance
Authors: Duvenage Estelle
Published: October 2006

Near infrared calibrations have been derived and used routinely for a year in the measurement of fat and moisture in air‐dried bread. First and second derivative calibrations were obtained using a Pacific Scientific mark II scanning spectrophotometer on samples sent from all over South Africa to the Wheat Board for analysis. Prediction analysis performed on further bread samples gave standard errors of prediction (s.e.p.) of 0.12% fat and 0.13% moisture.
The influence of processing conditions on the properties of dried Nemadactylus macropterus fillets
Authors: Wootton Michael , Ismail Noryati
Published: October 2006

Various brining times in saturated salt solution and various drying temperatures were used to produce dried Nemadactylus macropterus fillets. The quality of the products was assessed visually before and after reconstitution and also by scanning electron microscopy and isoelectric focusing of the water‐soluble proteins. Product quality deteriorated when brining times exceeded 24 h and also as drying temperatures rose. This was evidenced by poor appearance and reconstitution behaviour, disruption of surface and deep tissue and changes in soluble protein components. An acceptable product was obtained by brining for 8h followed by drying at 50°C. The composition of this product was comparable with that of some commercial dried fish products from South‐east Asia.
Preparation and properties of protein concentrate from broiler chicken heads
Authors: Fik M. , Surowka K. , Fik Miroslaw , Surowka Krzysztof
Published: October 2006

The object of this work was to establish the optimal technological conditions for the production of protein concentrate from the heads of broiler chickens by enzymic hydrolysis with papain. It was discovered that hydrolysis is most effective at a temperature of 60°C and a pH of about 7, with 2g of enzyme added per kilogramme of raw material. Under these conditions, 100 kg of heads yielded 7 kg of concentrate and 19.2 kg of waste for feed meal. The concentrate obtained contained about 85% protein and demonstrated good organoleptic and physicochemical properties.
Isolation of a mimosine degrading enzyme from leucaena leaf
Authors: Tangendjaja Budi , Lowry J. B. , Wills R. B. H.
Published: October 2006

An enzyme which catalyses the degradation of mimosine to 3‐hydroxy‐4(1H)‐pyridone(DHP) has been isolated from Leucaena leucocephala leaf by extraction with ammonium sulphate, purification on Sephadex G‐25 and fractionation on Sepharose 6B and gel electrophoresis. The enzyme was found to have a molecular weight of 140000, a Km value of 1.64 mM ml−1 and maximum reaction velocity of 0.3 mmol DHP produced ml−1 min−1. Tyrosine was a competitive inhibitor of the enzyme but DHP did not act as a feedback inhibitor. The enzyme has been termed ‘mimosinase'’.