bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of waterlogging at different stages of development on the growth and yield of peas (Pisum sativum L.)
Authors: Belford Robert K. , Cannell Robert Q. , Thomson Robert J. , Dennis Colin W.
Published: October 2006

The effects of waterlogging, for up to 8 days at different stages of development, on the growth and yield of peas have been examined. The peas were grown outdoors subject to field conditions in lysimeters containing monolith sandy loam or clay soils, in facilities where drainage and rainfall could be controlled. The experiments, made during 2 years, involved waterlogging treatments likely to be the most extreme occurring in the pea‐growing areas of the UK. During each waterlogging treatment the oxygen concentration at 20 cm depth in the soil declined to less than 2% within 2 days. On average, when the soil was waterlogged to the surface for 5 days at the 1–2, 3–4 and 6–7 leaf stages (the latter being just before flowering), the losses of yield of seeds (peas) at the freezing stage were 6, 15 and 42%, respectively. The severity of the effect depended on the duration of the treatment and the height of the water‐table; at the 6–7 leaf stage either 2 days waterlogging to the surface or 5 days with the water‐table at 50 cm below the soil surface had little effect on seed yield. Waterlogging restricted leaf expansion and internode extension. After waterlogging at the pre‐flowering stage, leaves usually senesced prematurely and the shoot apex became prematurely quiescent. In all experiments the yield of haulm was more affected by waterlogging than were the yields of pods and seeds. The losses in yield were mainly a consequence of fewer pods per plant. Waterlogging before flowering for 5 days depressed the concentrations of nitrogen, phosphorus and potassium in the haulm grown on both soils and of nitrogen in the seeds (peas) of plants in 1 year on the clay. Other treatments had little effect on nutrient concentration. After waterlogging to the surface for 5 days before flowering the uptake of water by roots was restricted, but other treatments had only a small effect, being least in the early treatments.
Properties of some protein fractions from bambara groundnut [Voandzeia subterranea (L.) Thouars]
Authors: Poulter Nigel H.
Published: October 2006

Eight cultivars of bambara groundnut [Voandzeia subterranea (L.) Thouars] were examined for their protein, non‐protein nitrogen, starch, reducing sugar, tannin and trypsin inhibitor contents. Protein (N × 5.71), starch and reducing sugar contents showed little inter‐cultivar variation giving mean values of 18.7, 42.1 and 1.26 g 100 g−1 whole seed, respectively. Tannin contents ranged from 0.36 to 0.94 g 100 g−1 whole seed and trypsin inhibitory activity from 6.75 to 15.44 units mg−1. The majority of the protein nitrogen present was extractable in water or dilute salt solution. Trypsin inhibitory activity was directly correlated with the quantity of protein nitrogen extracted from each of the cultivars, which in turn, was found to be inversely related to their tannin contents. This latter effect was modified by both the pH and the molarity of the extractant used.
Influence of isoelectric precipitation on the solubility of soya bean proteins
Authors: Lillford Peter J. , Wright David J.
Published: October 2006

The factors controlling the solubility characteristics of soya bean proteins consequent upon acid precipitation were investigated. Two processes of protein insolubilisation, fundamentally different in their effects, were identified. One, termed ‚pH sensitivity’︁, involved principally haemagglutinin and low molecular weight (2S) proteins, and was affected by exposure to low pH (4.5) in the presence of reducing agents; resolubilisation could be achieved by adjusting the pH to 7.6, but only at low ionic strength. The second process concerned a precipitation‐induced aggregation of the globulins which was produced in the absence of, and largely eliminated in the presence of, reducing agent. In this case, complete resolubilisation was afforded by readjustment of the pH to 7.6, either by back titration or dialysis against a phosphate buffer, but was not dependent upon the presence of reducing agent. The mechanisms underlying these insolubilisation processes were concluded to be mainly of an electrostatic nature, rather than ones involving disulphide exchange reactions.
A rapid screening method for the estimation of total glycoalkaloids in potato tubers
Authors: Coxon David T. , Jones P. Geraint
Published: October 2006

A rapid method for estimating the total glycoalkaloid (TGA) content of potato tubers is described which allows TGA content to be classified into three groups: (i) low TGA containing (< 15 mg TGA 100 g−1 fresh weight); (ii) high TGA containing (< 15‐35 mg TGA 100 g−1 fresh weight); and (iii) very high TGA (> 35 mg TGA 100 g−1 fresh weight). The method is intended for use by plant breeders, particularly when high TGA content might be expected in hybrid clones where one or both parents is derived from a wild species. The TGA concentration in juice expressed from potato periderm and cortex tissue was assayed by thin layer chromatography. The method utilises a direct relationship which was established between the glycoalkaloid concentration in expressed juice and the TGA content of the whole tuber and enables up to 50 analyses to be completed in 1 day by one operator without the need for expensive equipment.
Protein quality in seed meals of Phaseolus vulgaris and heat‐stable factors affecting the utilisation of protein
Authors: Phillips David E. , Eyre Michael D. , Thompson Alan , Boulter Donald
Published: October 2006

The polyphenol content of several cultivars of Phaseolus vulgaris was measured. The true digestibility (TD) and biological value (BV) of the cooked meals of two high‐polyphenol cultivars and one low‐polyphenol cultivar were determined by nitrogen‐balance experiments with growing rats. Removal of the testa caused a significant (P<0.05) increase in TD of Canadian Wonder and Masterpiece (high‐polyphenol) of 7.2 and 8.4%, respectively, but no significant increase in that of Processor (low‐polyphenol). Testa removal caused no significant change in BV. Supplementation of the three cultivars with methionine and cystine raised the BV to values similar to those obtained with egg albumin. Supplementation of Masterpiece with tryptophan caused no further increase in BV. The polyphenol content of the bean meals did not appear to affect the utilisation of their sulphur‐containing amino acids. Isolated Masterpiece globulins were found to be highly digestible (TD 95.4%) but with a low BV (28.36%) which was caused by a low sulphur‐containing amino acid content. The effects measured by rat feeding experiments could not be accounted for by trypsin inhibitors of phytohemagglutinin activity as the heat treatment used prior to the N‐balance studies was sufficient to destroy their activity. For the samples Masterpiece, Canadian Wonder and Processor, both with and without testa, and the isolated globulin fraction, the BV was highly correlated (P<0.001) with the total protein sulphur‐containing amino acid content.
The replacement value of sugarcane molasses for maize in sheep‐fattening rations
Authors: Umunna Nnanyelum N. , Maisamari Bala A.
Published: October 2006

Twenty‐eight Yankasa rams, about 1.5 years old and each weighing on average 27.9 kg, were individually fed one of four experimental diets, formulated to differ in the level of cane molasses which replaced maize in the diet: 0 (control), 10 (low), 20 (medium) and 30% (high). The diet comprised on a dry matter (DM) basis, 30% native hay (Andropogon and Hyparrhenia spp. predominating) and 70% concentrate and provided a dietary crude protein level of approximately 12.5%. The results (average daily gain, feed intake and feed conversion efficiency) showed that molasses replaced 30% maize (DM basis) in fattening rations without detrimental effects. Carcass data showed that rams which received the low and medium molasses diets had better dressing percentage and wholesale cuts. Dry matter and protein digestibilities were not significantly affected by the treatments. The economic advantages in the use of molasses in fattening rations is attractive given the wide price differential (in Nigeria) between maize and molasses.
Determination of carboxyl groups in wheat and barley flour proteins
Authors: Ewart John A. D.
Published: October 2006

The method of Hoare and Koshland for the estimation of free carboxyl groups in proteins has been scaled down and applied to wheat proteins. With standard proteins, provided the carboxyl groups were not inaccessible (as in lysozyme), the error was as large as 19%. This level of error is acceptable for estimating by difference amide contents when these are high, as in gluten proteins, because the error is greatly reduced by the molar ratio of side‐chain CONH2:COOH—a ‚leverage’︁ effect. About 95% of the side‐chain COOH groups appear to be amidated in the prolamins and about 50% in the albumins. The proportion of Glx + Asx in the amide form seems to decrease slightly as the electrophoretic mobility of a prolamin increases. The errors in calculating the numbers of positive and negative charges that a protein bears at pH 8.9 become serious when superimposed on the net charge, which is the small difference between these numbers. The net charge at pH 8.9, therefore, could not be obtained accurately by calculation. The polarity of the net charge can be determined by electrophoresis using a marker for electroendosmosis.
Constitution of leguminous seeds. A note on protein‐phytic acid interactions during isolation of acid‐soluble protein from phaseolus beans
Authors: Alli Inteaz , Baker Bruce E.
Published: October 2006

Acid‐soluble proteins isolated from three types of Phaseolus beans (white kidney beans, navy beans and lima beans) were found to contain phytic acid. The amount of phytic acid complexed by the proteins was unaffected by the phytic acid content of the bean extracts from which the proteins were isolated but depended on the number of positively charged basic groups which were available for reaction with the phytate anion. It was found that the Neuberg formula for phytic acid (C6H24O27P6) represents more accurately the molecular formula of phytic acid associated with the isolated proteins, than does the Anderson formula (C6H18O24P6).
Fractionation and determination of the carbohydrate components from microbial products
Authors: Longe O. Grace , Norton Grenville , Lewis Dyfed
Published: October 2006

A routine procedure was developed which enabled a complete quantitative analysis of the carbohydrate components of microbial products to be achieved within a few days. Using the procedure, the complete carbohydrate composition of two yeasts grown on hydrocarbons and a filamentous fungus grown on carbohydrate waste was determined. Glucose was the predominant sugar contained in the polysaccharide fractions from all samples. Mannose was present to a lesser extent and glucosamine was present in trace amounts. Galactose was found in trace amounts in one of the yeasts but was found in slightly higher amounts in the fungus grown on carbohydrate. Carbohydrates accounted for 22.4‐23.6% of the dry matter of hydrocarbon grown yeasts and 21.7% for the filamentous fungus.
Starch and sugar transformation during the ripening of plantains and bananas
Authors: Marriott John , Robinson Michael , Karikari Simon K.
Published: October 2006

Ripening changes were studied in plantains of three cultivars, two Horn types and one French type, and compared with those in bananas ripened under the same conditions. Bananas contained 1% starch when fully ripe and none when overripe, whereas plantains contained about 9% starch when fully ripe and 3% when overripe (composition expressed as percentage fresh weight). Total sugar content was 23% in fully ripe and overripe bananas but in plantains it increased from 20% when fully ripe to 27% when overripe. The ratio of glucose:fructose was approximately unity for bananas and plantains at all stages of ripeness. Sucrose comprised more than 70% of the total sugars in fully ripe bananas and plantains and about half of the total sugars in overripe fruits.
Rapid gas‐liquid chromatographic determination of low levels of erucic acid in rapeseed using an internal standard
Authors: Wilson Nancy L.
Published: October 2006

A method is described for rapid determination of erucic acid in low erucic rapeseed. The method is suited primarily to erucic acid levels below 1 % and so provides greater sensitivity and accuracy than other procedures adapted to this range. Oil is expressed by means of rollers and the fatty acids are routinely transmethylated before gas‐liquid chromatographic separation isothermally at 215°C. For maximum speed and accuracy the methyl ester of tricosanoic acid (C23:0) is included as internal standard. It elutes after erucic acid (C22:1) and within 15 min of injection. Satisfactory resolution of behenic (C22:0) and erucic acids is achieved, with good separation from other fatty acids and from the internal standard, on a steady baseline. Using one column repeatedly or two columns alternately, approximately 30 samples can be analysed in 1 day. With dual integrators the sample output can be doubled. Within the range below 1 % erucic acid, oils of high (0.9% m/m) and low (0.2% m/m) content returned coefficients of variation (c.v.) of ± 1.1 % and ± 2.5%, respectively. When rapeseed sample variation was included, precision fell away and c.v. changed to ± 7% and ± 12%, respectively. Sample variation is examined briefly and suggestions are made to reduce this source of error.
A pilot‐plant cellulose acetate gel bead column for the removal of limonin from citrus juices
Authors: Johnson Robert L. , Chandler Bruce V.
Published: October 2006

A description is given of a pilot‐plant column packed with cellulose acetate gel beads for the removal of the bitter principle limonin from pasteurised citrus juices, at about 20 °C. The column had a bed volume (BV) of 11.5 litres and in a representative run the passage of juice (11 BV) through the column at a flow rate of 2.5 BV h−1 reduced the limonin content of the juice from 19.2 to 10.9 mg litre−1. The adsorptive process can be described by standard mathematical equations and from these equations the theoretical performance of units consisting of two or more columns in series or parallel can be calculated. For example, passage of juice (20 BV) containing 35 mg litre−1 limonin through two columns in series would reduce the limonin content to 14 mg litre−1 compared with 19 mg litre−1 following passage through parallel columns. Treatment of fresh, unpasteurised juice reduced limonin contents by only 15% but treatment of freshly pasteurised juice was almost as successful as that of 1‐day‐old pasteurised juice. Since, like freshly extracted juice, freshly pasteurised juice is not bitter, it is suggested that two non‐bitter limonin precursors are involved in bitterness development, only one of which is adsorbed by cellulose acetate.
Some characteristics of the roots of the winged bean [Psophocarpus tetragonolobus (L.) DC]
Authors: Poulter Nigel H.
Published: October 2006

Three accessions of winged bean [Psophocarpus tetragonolobus (L.) DC] tuberous roots from Thailand were examined for their crude protein (N × 6.25), non‐protein nitrogen and starch contents. The roots were further analysed for their trypsin inhibitor and urease activities and for the presence of tannins and cyanogenic compounds. Crude protein was found to be high in comparison with other root crops (5.7–6.7% fresh weight) and this contained a high proportion of non‐protein nitrogen (7.4–15.0%). Amino acid content of the crude protein, when compared with mature winged bean seeds, revealed a deficiency in the sulphur‐containing amino acids but an exceptionally high aspartic acid content. Starch was the major carbohydrate present in the flesh of the roots (21.7–32.1% fresh weight). Root samples were found to contain high levels of trypsin inhibitory activity (13.5–30.1 TIU mg−1 fresh weight). No urease activity or cyanide could be detected in any of the root accessions studied.
Influence of some husbandry practices on the physical properties of spring barley grain
Authors: Taylor B. Richard , Blackett George A.
Published: October 2006

Specific weight, 1000 grain weight, and percentages of grain held by a 2.5 mm sieve and passing through a 2.2 mm sieve were measured in husbandry trials carried out on spring barley at Craibstone, Aberdeen, from 1975 to 1979. Sowing date had the greatest influence on these properties, apparently due more to poor crop development than to increased foliar disease following late sowing. Fungicide treatment, particularly a spray application of tridemorph, resulted in an improvement, but growth regulators, especially when applied late or at high rates, had the reverse effect and both chemicals affected specific weight less than other parameters. The mean specific weight, 1000 grain weight and grain size of a number of varieties declined at nitrogen application rates above 50 kg ha−1, but there were significant differences between varieties, with short‐strawed, small‐grained varieties such as Midas and Maris Mink being most affected. Different levels and application methods of phosphatic fertiliser had little effect on the parameters measured.
Development of a method to measure dietary fibre in oranges
Authors: Dovell C. J. , Harris N. D.
Published: October 2006

A method to measure dietary fibre in oranges has been developed. Pectin was extracted from the food sample using heat, acid and a cation‐exchange resin. This was followed by enzymic digestions, using pepsin and pancreatin, of the remaining residue. Optimal levels of resin, pH, time and temperature for maximum pectin extraction were found. Optimal levels of enzymes and pH for maximal enzyme digestion was also found. Other food products tested for dietary fibre content were: cauliflower, oranges, pole beans, carrots and whole wheat flour. Values found were greater than those for other fibre analyses; however, most other methods fail to measure the water‐soluble indigestible components, such as pectin.
Characteristics of kernel oils from Elaeis oleifera, F1 hybrids and back‐cross with Elaeis guineensis
Authors: Tan Boon K. , Berger Kurt G.
Published: October 2006

Kernel oils from different palms of Elaeis oleifera, F1 hybrids and back‐cross with Elaeis guineensis were analysed for iodine value, fatty acid and triglyceride composition. Kernel oils of F1 hybrids and back‐cross were close in fatty acid and triglyceride composition to that of E. guineensis. Kernel oils of E. oleifera showed a different triglyceride distribution pattern to that of E. guineensis.
Ingestion and retention of mercury by sheep grazing near a chlor‐alkali plant
Authors: Edwards Philip R. , Pumphrey Nicholas W. J.
Published: October 2006

An experiment is described in which a flock of sheep was kept for 23 months on a field contaminated with mercury as a result of atmospheric emissions from a chloralkali site. The mercury concentration found in the flesh of the sheep during the trial was within the range present in other commercially available meat. Levels of mercury found in the kidney and liver were elevated, although < 10% of the mercury in the organs or the flesh was in the methylated form. About 0.1% of the total mercury taken in by inhalation and ingestion was retained by the sheep. The breeding performance of the flock was normal. It is concluded that contamination of grass as a result of atmospheric discharges of inorganic mercury from UK chlor‐alkali sites causes no hazard either directly to grazing animals or indirectly to humans who might ultimately consume their flesh.
The changes in cyanide content of cassava (Manihot esculenta crantz) tissues during plant development
Authors: Cooke Rodney D. , de la Cruz Elba M.
Published: October 2006

The cyanide concentrations in the leaves, meristems, root cortex and root parenchymal tissues of cassava (cv. Valencia) were investigated at 2‐month intervals up to a plant age of 17 months. Six plants were analysed at each interval and sampling methods investigated to ensure that the cyanide estimations (by enzymic assay) were representative for each plant. Root yield per plant increased to 10 months and then remained almost constant to 17 months. Leaf weight per plant reached a maximum at 6 months (380 g per plant), decreased to 12 months and then slowly increased. Cyanide concentrations in the root parenchymal tissue and root cortex were not significantly different between 6 and 14 months; both tissues displayed peak concentrations at 6 and 14 months. Cyanide concentration maxima in the leaves appeared to precede those shown by the roots. Meristem concentrations showed similar trends to those shown by the leaves. The precise plant age at harvest had little effect on the potential toxicity of the roots. A modification to the earlier published procedure for leaf tissue is described. The cyanide concentration in old (green) leaves was < 50% of that in young leaves of the same plant. Intra‐leaf and inter‐leaf cyanide concentration variations are described, and the importance to low‐cyanide cassava screening programmes indicated.
Insulin secretion in relation to fatness in cattle
Authors: Gregory Neville G. , Truscott Terry G. , Wood Jeffrey D.
Published: October 2006

The insulin secretory response to tolbutamide was examined in cattle to determine: whether this agent is insulinogenic in this species, what effect age has on insulin secreting ability, and whether the insulin response is related to body fatness. Intravenous injection of sodium tolbutamide (27 mg kg−0.75) caused a three‐ to sevenfold rise in plasma insulin concentration, but the response was delayed and protracted in comparison with that seen in non‐ruminants. The insulin response was higher at 20 than at 12 months of age. The insulin response was not related to the proportion of dissectible fat in the empty body, and it was lower in Hereford than Friesian steers despite the Herefords being slightly fatter. It was concluded that tolbutamide is insulinogenic in cattle and its effectiveness increases with age. Unlike the non‐ruminant, there is no association between fatness and insulin response to tolbutamide in cattle compared at the same age.
Distribution of 45Ca between soluble and colloidal phases of buffaloes' milk as affected by processing
Authors: Sindhu Jagveer S. , Roy Nirendra K.
Published: October 2006

The distribution of 45Ca between the soluble and colloidal phases of skimmed buffaloes' milk, and the effects of five processing treatments, was determined by the rennet coagulation technique. The five processing treatments consisted of pasteurisation (at 71.8°C for 15 s), pre‐warming (at 96°C for 5 min), sterilisation (at 121.5°C for 15 min), and cooling (for 24 h at 4–6 and 0°C). The proportion of 45Ca in the soluble phase of raw milk was about 44% (in vitro) and 37% (in vitro), while that of original Ca was about 21% (control). In vitro, pasteurisation, pre‐warming and sterilisation progressively decreased the amount of 45Ca incorporated into the soluble phase to about 39, 31 and 27%, respectively. The decline of incorporated 45Ca was statistically significant (P < 0.01) for the prewarming and sterilisation of milk. In vitro, the decline of incorporated 45Ca or the transfer of 45Ca from the soluble to the colloidal phase due to the heat treatment, was small, irregular and not significant. Changes due to cooling were not significant for any of the experiments. Significantly different results were observed for the partitioning of Ca when comparisons were made between in‐vitro introduced 45Ca and original Ca, and between in‐vivo incorporated 45Ca and original Ca.
Seasonal variation in the viscosity of the extracts of muscle proteins of hake (Merluccius hubbsi) stored on ice
Authors: Barassi Carlos A. , Crupkin Marcos , Martone Celina B. , Trucco Raúl E.
Published: October 2006

Changes in viscosity of high‐ionic‐strength muscle extracts of hake stored on ice are subject to seasonal variation. A rapid fall in the viscosity occurs in extracts of fish caught during the summer. The viscosity declines at a slower rate after the sixth day of storage for those fish caught during the autumn. No change in the viscosity was observed in hake caught during the winter and spring.
The reactivity of intermediates in non‐enzymic browning reactions towards nitrite ion
Authors: Wedzicha Bronislaw L. , Hill David , Cockshott Janet B.
Published: October 2006

The intermediates of non‐enzymic browning reactions, 4, 5‐dihydroxy‐2‐oxopentanal and 2‐oxo‐4,5,6‐trihydroxyhexanal, show significant reactivity towards nitrite ion at pH 4.7 and 7.0, respectively.
Leaching losses of nutrients and yield and nutrient uptake by container‐grown begonia as affected by lime and fertiliser applications to a peat medium
Authors: Haynes Richar D. J.
Published: October 2006

The effect of increased lime applications and one rate of soluble basal fertiliser on leaching losses of NH4‐N, NO3‐N, P, Ca, Mg and K from peat in containers was studied in the presence or absence of Begonia semperflorens plants in a greenhouse pot experiment. Percentage recoveries (leached, plus extractable nutrient remaining in the peat, plus plant uptake) of mineral N and P were in the range of 60–80% while those for Ca, Mg and K ranged from 95 to 111%. Percentage leaching losses in the absence of plants were: mineral N, 75–76%; P, 59–74%; Ca, 5–7%; Mg, 14–19%; and K, 17–31%. In the presence of plants, the average decrease in the percentage loss of nutrients by leaching was: N, 9.3%; P, 4.4%; Ca, 0.5%; Mg, 0.3%; and K, 1.3% Liming tended to decrease leaching losses of NH4‐N, P, Ca and Mg but increase those of K and NO3‐N. The phosphate adsorption capacity of the peat was not measurable but significant ammonia fixation from added (NH4)2SO4 was demonstrated at high pH (>6.5) concomitant with high N rates (> 300 g N m−3). Effective cation‐exchange capacity (CEC) and CEC measured with unbuffered 1m NH4CI were both more than doubled with increased lime additions as the pH of the peat increased from 4.3 to 5.6. The conventional CEC measurement (NH4OAc, pH 7.0) and BaCl2‐TEA (pH 8.2) CEC both remained unaffected by the initial lime rates, and both greatly overestimated the CEC of the peat at its unbuffered pH.
The effect of water stress and form of nitrogen on the incidence of blossom‐end rot in tomatoes
Authors: Dekock Pierre C. , Hall Alexander , Boggie Robert , Inkson Robert H. E.
Published: October 2006

The effects of water stress, ammonium sulphate, sodium nitrate and ammonium nitrate on the incidence of blossom‐end rot (BER) in tomatoes was studied, using plants grown in peat modules. There was little evidence that water stress per se affected BER incidence, which was largely determined by the ammonium ion, as found in previous studies. Water stress increased ammonium and nitrate levels in both the peat modules and the leaves of the plants. This effect may account for the relation between moisture stress and BER reported by others.
An investigation into some causes of the differences of protein expressibility from leaf pulps
Authors: Butler Jonathan B.
Published: October 2006

On a laboratory scale, changes in expressibility of protein with age from leaf pulp of lucerne, amaranth, garden orache, sunflower, fat hen, dock and field beans were not closely correlated with changes of fibrous dry matter, cell robustness, pH or tannin content. However, for amaranth, garden orache and fat hen, a strong correlation was found between protein expressibility and the proportion of the total leaf water that was expressed. This suggests that expressibility from those species was determined more by the proportion of leaf water that was expressed as juice than by the concentration of protein in the juice. Interspecific differences of protein expressibility between fat hen, amaranth, sunflower, beans and pea, all at the same age, were strongly correlated with differences in leaf tannin content. However, garden orache was also examined and it did not fit the pattern established by the other crops. Therefore, the correlation exhibited by the other crops may not be general.
A kinetic study of bread staling by differential scanning calorimetry. The effect of loaf specific volume
Authors: Fearn Tom , Russell Peter L.
Published: October 2006

Changes in the starch fraction of bread at 21°C have been measured as a function of loaf specific volume using differential scanning calorimetry (DSC). Data from five bakes were fitted by Avrami equations Ø = exp (‐ktn) (where Ø is the fraction of the total thermal change still to occur) using an iterative non‐linear least squares procedure which enabled simultaneous estimation of limiting value, rate constant (k) and Avrami exponent (n). The method allowed the fit of a number of different models to be tested. It was concluded that Avrami exponents from each bake were the same and < 1 and that the rate constants were also equal. For comparison, crumb compressibility measurements were made on the same loaves used for DSC. These data were also analysed in a similar way. An adequate fit in this case was given by an Avrami exponent of 1; however, rate constants appeared to vary with loaf specific volume.
Effect of moisture content on the development of carboxylic acids in traditional maize dough fermentation
Authors: Plahar W. A. , Leung Henry K.
Published: October 2006

Maize dough samples containing 45, 52, 65 and 80% initial moisture were fermented over a 3 day period, and the rate of development of carboxylic acids was determined. The desired volatile: non‐volatile acids ratio of 0.16, titratable acidity of 2.4 mg NaOH g−1 sample, and pH of 3.7 could be achieved with only the 52% moisture samples. A slow rate of acid production and an early onset of mould growth was observed in samples with 45% moisture. The 65 and 80% moisture samples developed high concentrations of acids with resultant high degree of sourness. Acetic, propionic and butyric acids were the major volatile acids in samples with moisture contents over 52%.
Effect of gamma irradiation on aflatoxin production in barley
Authors: Chang Hak‐Gil , Markakis Pericles
Published: October 2006

Barley was inoculated with conidia of Aspergillus parasiticus NRRL 2999, and at 0°C was left to equilibrate at three moisture levels: 17, 20 and 25%. Gamma irradiation at five doses, 0, 50, 100, 200 and 400 krad, was applied to the grain either soon after moisture equilibration (3 days after inoculation) or 10 days later (13 days after inoculation). Increasing the radiation dose resulted in decreasing aflatoxin formation, with one exception: 200 krad applied 13 days after inoculation on barley stored at a moisture level of 25% (100% relative humidity) and 25°C led to higher aflatoxin production than at 100 or 50 krad. For the control of aflatoxin contamination in barley, storage at low moisture content appears to be more practical and effective than irradiation.
Ultrastructure of denaturated potato proteins
Authors: Shomer Ilan , Lindner Pinhas , Ben‐Gera Itamar , Vasiliver Rosa
Published: October 2006

The structure of potato protein precipitates formed by heat treatment or acidification of potato juice was investigated by transmission electron microscopy. Precipitates formed by heat denaturation (3 min at 100°C) consist of electron‐dense particles of diameter < 300 nm, aggregated into three‐dimensional open networks. Precipitates, formed by acidification to pH 3.0 and holding the acidified juice at room temperature, consist of network‐like aggregates of electron‐dense particles embedded in thin films which hinder the formation of a dense sediment. This structure explains the high sediment volumes which are typical of this kind of precipitate. By warming the acidified potato juice to 40°C, rapid flocculation and sedimentation of the suspended insoluble protein are observed within a few minutes and a dense sediment is finally obtained. This sediment consists mainly of the network‐like aggregates of electron‐dense particles and material of low electron density formed by the collapse of the films. Protein films have also been observed in precipitates of heat‐denatured bovine serum albumin (BSA). High‐methoxyl pectin promotes the formation of protein films on heat denaturation of potato proteins or BSA.
A comparison of seed phosphatides and synthetic compounds as antioxidants for cow and buffalo ghee (butter fat)
Authors: Kaur Narinder , Sukhija Pritam S. , Bhatia Iqbal S.
Published: October 2006

The antioxidant capacity of seed phosphatides and synthetic antioxidants when compared in cow ghee was found to be in the order: phosphatidyl ethanolamine < propyl gallate <palmitoyl ascorbate <butylated hydroxy anisole < phosphatidyl choline. Phosphatidyl ethanolamine was found to be the most effective antioxidant. Cow ghee had less peroxide development than buffalo ghee. The ghee prepared at 100°C was more stable against peroxide development compared with that prepared at 50°C. These observations were supported by the analysis of ghee samples for peroxide values and for fatty acids. The phosphatides imparted more antilipolytic activity to ghee then to synthetic antioxidants.
The digestibility and chemical composition of plant parts in Italian and perennial ryegrass during primary growth
Authors: Wilman David , Altimimi Mehdi A. K.
Published: October 2006

Italian ryegrass (cv. S22) and perennial ryegrass (cv. S24) were sampled duringprimary growth at head emergence, pollen shedding and seed shedding in each of 2 years. Each sample was separated into approximately 19 plant parts and for each part the true dry matter digestibility, digestibility of cell wall and percentages of cell content, nitrogen, water‐soluble carbohydrate and lignin were determined. Trends reported in the literature, based on a smaller number of plant parts, were generally confirmed, but were shown to conceal appreciable variation. Thus, while, on average, stem declined in digestibility faster than leaf sheath, the upper sheaths declined in digestibility faster than the lower internodes and nodes; similarly, the proportion of cell content declined at a rather similar rate to digestibility in leaf blade and much less than digestibility in stem but the position was reversed between pollen shedding and seed shedding in the case of dead leaf blade and internodes. While the N content of the inflorescence as a whole did not decline greatly with advancing maturity, the N content of the rachis was nearly halved. The upper part of the crop was more digestible than the lower part at head emergence, but not at seed shedding. Italian ryegrass had a higher proportion of cell content than perennial ryegrass in all types of plant part. The digestibility of cell wall declined with advancing maturity in all the plant parts examined. The lower portions of internodes had a higher proportion of cell content than the upper portions. There were gradients from top to bottom of the plant, e.g. percentage N declined and percentage water‐soluble carbohydrate increased from top to bottom.
The conditioning of wheat. The influence of roll temperature in the bühler laboratory mill on milling parameters
Authors: Hook Simon C. W. , Bone Geoffrey T. , Fearn Thomas
Published: October 2006

The effect of roll temperature increases observed during successive millings using a laboratory Bühler mill has been investigated for both UK and Canadian wheats. A sequence of four millings each day, at fixed times, has been employed for experimental work on the conditioning of wheat. The results of four successive days' milling of a single wheat sample have shown that flour yield increased with each successive daily milling for the UK wheats but only for the first three millings with Canadian wheat. In both cases flour moisture fell throughout the day and the rate of decrease appeared to be unaffected by wheat texture. Flour colour and ash content were largely unaffected during the daily milling programme. The results obtained can be used to correct for these ‘order of milling’ effects that would otherwise influence the results of milling data in subsequent studies on wheat conditioning.
Phenolic acids in pig slurry subjected to various treatment processes
Authors: Garraway James L. , Ramirez Maureen E. A.
Published: October 2006

Thin‐layer chromatography of extracts of raw and treated pig slurries revealed the presence of phenolic acids. The number of phenolic acids present in raw slurry was reduced considerably by aeration and, to a smaller extent, by treatment with hydrogen peroxide; anaerobic storage and digestion proved ineffective for the removal of phenolic acids from pig slurry.
The detoxification of pot ale and other copper‐rich effluents by cementation of copper on aluminium metal
Authors: Ure Allan M. , Welch Karen H.
Published: October 2006

A method is described for the removal of copper from copper‐rich effluents such as pot ale—a waste product from malt whisky distillation in copper stills. This method makes use of cementation on aluminium metal, obtained cheaply from aluminium beer cans, and could be of potential practical value for the detoxification of copper‐rich effluents such as pot ale and pig slurry before disposal to agricultural land. Traces of silver, gold and platinum have been found in pot ale by a spark source mass spectrographic technique which also uses a cementation procedure to pre‐concentrate trace elements on to aluminium metal.
The tryptophan content of some feedingstuffs for poultry
Authors: McNab James M. , Scougall Robert K.
Published: October 2006

The tryptophan contents of a range of raw materials which are commonly included in poultry diets have been determined by a modification of a previously published procedure. It is based on the enzymic release of tryptophan from the protein source and its subsequent reaction with dimethylaminocinnamaldehyde. The values obtained for the animal protein sources, cereals and soya bean meal agree well with previously published data. However, the tryptophan contents of other vegetable proteins agree less well with values published elsewhere and that for rapeseed meal is considerably lower. The method is suitable for application in a quality control laboratory where one operator can process eight samples daily.
The development of universal calibrations for measurement of protein and moisture in UK home‐grown wheat by near‐infrared reflectance analysis
Authors: Osborne Brian G. , Douglas Stuart , Fearn Thomas , Willis Kenneth H.
Published: October 2006

Near‐infrared reflectance analysis was used to measure protein and moisture contents of UK wheat samples over five harvests (1975–1979 inclusive). The use of universal constants produced stable instrument calibrations valid for both hard and soft varieties and all growing locations in the UK which required no more than an annual bias adjustment except for 1976, a year when unusual climatic conditions prevailed in UK. The universal calibrations were achieved by the statistical selection of stable subsets of wavelengths. The accuracy of the calibrations when compared with classical methods (oven drying and Kjeldahl) was 0.25% or better for both moisture and protein.
Legume pectic substances and their degradation in the ovine rumen
Authors: Chesson Andrew , Monro John A.
Published: October 2006

Red clover and lucerne samples, and their leaf + petiole and stem fractions were sequentially extracted with cold water, chloroform‐methanol, boiling water and boiling 5 g litre−1 ammonium oxalate and the composition of the cold water, hot water and oxalate extracts and the extracted residues determined. Hot‐water‐soluble galacturonan was found to be more highly acetylated and esterified and to be associated with approximately ten times more neutral sugar residues than oxalate‐soluble galacturonan. The major neutral sugars associated with both fractions were arabinose, galactose and rhamnose. Hot‐water‐soluble uronide from stems was also more highly acetylated and associated with more neutral sugar than the corresponding extract of leaf tissue. Despite differences in chemical composition, hot‐water and oxalate‐soluble galacturonan were lost at approximately the same rate from whole plants, and from stem and leaf fractions incubated in nylon bags in the rumen of a sheep. The maximum extent of degradation was reached within 18 h, thereafter little additional material was lost. Hot‐water‐soluble galacturonan, particularly from clover, was degraded to a slightly lesser extent (85–95%) than oxalate‐soluble galacturonan (95–98%). This difference did not relate to an accumulation of acetylated or esterified residues, nor to an accumulation of neutral sugar residues. Loss of associated neutral sugars paralleled the loss of uronic acid from all extracts. Hot‐water and oxalate‐soluble galacturonans were lost at faster rates than those shown by the other structural polysaccharides of the cell wall.
Detection of the illicit extension of potable spirituous liquors using 13C: 12C ratios
Authors: Simpkins Wayne A. , Rigby Donald
Published: October 2006

The stable carbon isotope ratios of 122 samples of common liquors and nine ferment able substrates have been determined. The δ13C values of the liquors analysed reflected those in the plant from which the fermentable substrate was derived. These values ranged from —23.4 to– ‐26.0% relative to Pee Dee Belemnite (PDB) for substrates derived from C3 plants while those from C4 plants ranged from —10.3 to —11.8% PDB. The application of this technique to detect the illicit extension of whisky has been investigated. As little as 2.9% grape spirit or 5.7% molasses spirit can be detected in whisky although the lower limit is dependent on the δ13C value of both the authentic whisky and the diluent. Measurement of 13C: 12C ratios could also be used to check that imported brandies conform with local requirements.
Bitterness in brussels sprouts (Brassica oleracea L. var. gemmifera): The role of glucosinolates and their breakdown products
Authors: Fenwick G. Roger , Griffiths Nerys M. , Heaney Robert K.
Published: October 2006

The bitterness associated with certain cultivars of Brussels sprouts has been shown to be linked to the presence of the glucosinolates, sinigrin and progoitrin. Whereas the former compound is bitter per se, the bitterness associated with the latter compound is due to its decomposition product, the goitrogen (‐)5‐vinyloxazolidine‐2‐thione. A method is described for the screening of cultivars of this, and other, Brassica vegetables for potential bitterness.
A survey of the occurrence of the trichothecene mycotoxin deoxynivalenol (vomitoxin) in UK grown barley and in imported maize by combined gas chromatography‐mass spectrometry
Authors: Gilbert John , Shepherd Martin J. , Startin James R.
Published: October 2006

A UK survey for the occurrence of the Fusarium mycotoxin deoxynivalenol (vomitoxin) in 87 samples of both feeding and malting barleys has shown levels of less than 0.02 mg kg−1 in 90% of the samples. The barleys containing deoxynivalenol (0.02–0.36 mg kg−1) were mostly feeding samples and showed no geographical trend within the UK. In contrast, for imported maize and brewers maize, only 25% of the samples showed levels less than 0.02 mg kg−1 deoxynivalenol, the remainder ranging from 0.02‐1.4 mg kg−1 with ten samples (36% of the total number analysed) having levels greater than 0.1 mg kg−1. All samples were analysed by combined gas chromatography‐mass spectrometry (selected ion monitoring) of the TMS deoxynivalenol derivative. For two of the maize samples full mass spectra were obtained of the deoxynivalenol showing very good agreement with reference spectra and confirming the identity of the trichothecene.
Trapping of soursop (Annona muricata) juice volatiles on porapak Q by suction
Authors: Franco Maria Regina B. , Rodriguez‐Amaya Delia B.
Published: October 2006

The trapping technique of Singleton and Pattee, in which the volatiles are swept to a Porapak Q trap by suction rather than by a sweeping gas, was modified and used to isolate soursop juice volatiles. Using fixed, low vacuum and operating conditions determined specifically for soursop volatiles, very high reproducibility was obtained. The majority of the peaks had a coefficient of variation less than 0.10. The relative amounts of the volatile components obtained by direct headspace sampling was fairly well maintained in the Porapak Q concentrate. The chromatograms showed distinct differences between two commercial brands or between lots of the same brand of soursop juice. The trapping technique appear to have wide applicability provided that the operating conditions are adapted to each product studied.
Aggregation states of alcohol‐soluble storage proteins of barley, rye, wheat and maize
Authors: Field J. Michael , Shewry Peter R. , Miflin Benjamin J.
Published: October 2006

Two approaches were used to study the aggregation states of prolamins extracted from milled whole grain of wheat, barley, rye and maize with 500 ml litre−1 aqueous propan‐1‐ol. In the first, a comparison was made of the electrophoretic patterns of the samples separated by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS‐PAGE) under reducing and non‐reducing conditions. In the second, they were chromatographed on a column of controlled pore glass (CPG) using a modified acetic acid, urea, cetyltrimethyl ammonium bromide (AUC) solvent and aliquots of the major peaks were reduced and analysed by SDS‐PAGE. When the CPG chromatography was repeated under reducing conditions some of the peaks were eliminated indicating that they were composed of disulphide‐linked aggregates. The results from both approaches showed that in barley, rye and wheat the HMW prolamins and some of the S‐rich prolamins (B hordein, some γ‐secalins and subunits of high molecular weight gliadins) are present predominantly or partially in high molecular weight (above 1 × 106 daltons) aggregates which appear to be stabilised by disulphide bonds. Other S‐rich prolamins (including some γ‐secalins, α, β and γ‐gliadins) and all the S‐poor prolamins (‘C’ hordein, ω‐secalin, ω‐gliadin) are present predominantly or only as monomers. These results are discussed in relation to the structural and genetic homology of the prolamins in the three species. Although prolamin aggregates are also present in maize, these are of lower molecular weight.
Chlorinated residues in the adipose tissue of pigs treated with γ‐hexachlorocyclohexane
Authors: Mottram Donald S. , Psomas Ioannis E. , Patterson Ronald L. S.
Published: October 2006

Experiments were conducted to study the metabolic fate of γ‐HCH used in pig husbandry, and to see if a relationship existed between its use and the occurrence of 1,4‐dichlorobenzene and other chlorobenzenes in pork meat. Both oral administration and spray application of γ‐HCH led to the rapid accumulation of γ‐HCH and several metabolites in the adipose tissue. The following compounds were identified by gas chromatography and mass spectrometry: monochlorobenzene, 1,2‐, 1,3‐ and 1,4‐dichlorobenzene, 1,2,4‐trichlorobenzene, 1,2,4,5‐, 1,2,3,5‐ and 1,2,3,4‐tetrachlorobenzene, pentachlorobenzene, γ‐3,4,5,6‐tetrachlorocyclohexene, γ‐2,3,4,5,6‐penta‐chlorocyclohexene and α‐hexachlorocyclohexane. Concentrations of residual γ‐HCH and its metabolites were related to the amount of γ‐HCH applied initially to the pigs. γ‐HCH residues and the metabolites were monitored by biopsy and were found to be eliminated rapidly from the adipose tissue, such that pigs sprayed once with a dose 16 times greater than the recommended rate had a residual γHCH concentration, 30 days after treatment, no greater than that in untreated controls. The origin of 1,4‐dichlorobenzene and other chlorobenzene compounds is discussed in relation to the low levels of these compounds often found in flavour extracts of pork meat.