bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of the micrometeorological mass balance method to the determination of ammonia loss from a grazed sward
Authors: Ryden John C. , McNeill James E.
Published: October 2006

The micrometeorological mass balance method has been assessed with a view to its use in the determination of ammonia (NH3) loss from grazed swards. The method involves the measurement of wind speed and the concentration of NH3 in air at different heights above the sward at its windward boundary and a position leeward of the grazed area. The flux of NH3 is calculated from these measurements and a continuous record of wind direction. Quantitative recovery of NH3 from air flows up to 10 litre min−1 was achieved using a simple trap containing dilute orthophosphoric acid and a gas dispersion tube. Wind speed measured at a height of 0.25 m at six different positions above a previously grazed sward varied by <2%. The NH3 concentration at the same positions was affected by the distance between the windward edge of the sward and the sampling position (i.e. the fetch) and by heterogeneity in the distribution of sources of NH3 (urine‐ or dung‐affected areas). However, the normalised horizontal flux through 0.25 m (wind speedXNH3 concentration/fetch) varied by less than ±8.1% probably due to mixing through fluctuations in wind direction (approximately ±30° on the mean) as air passed over the sources of NH3 during each measurement period. Plots of wind speed or NH3 concentration versus logarithm of height indicated that each approximated a linear relationship. This facilitated the calculation of the NH3 flux per unit land area and reduced the total error to about 10%. The total loss of NH3 derived by summing losses during individual sampling intervals of 2 to 18 h within a 24 h period was essentially the same as that derived by averaging wind speeds and NH3 concentrations measured continuously over the same 24 h period. The flux of NH3 from a ryegrass sward grazed by yearling steers ranged from 0.01 to 0.14 kg N ha−1 h−1 during a 2 day grazing period within a 28 day rotation and during the 5 days following removal of animals. A pronounced diurnal variation was observed in the flux of NH3, the maximum occurring between 13.00 and 20.00 hours on each day. Rainfall and low rates of evapotranspiration reduced the flux to <0.02 kg N h−1 h−1. The total loss of NH3 during 28 days was 20.7 kg N ha−1.
Varietal differences in the mineral composition of bulked samples of fruit from Cox's Orange Pippin, Crispin (Mutsu) and Spartan apple trees
Authors: Perring Michael A.
Published: October 2006

Concentrations of dry matter, nitrogen and major mineral constituents in samples of Cox's Orange Pippin and Crispin fruit from interplanted trees were measured for 4 years. Similar measurements were made over a 6 year period in Cox and Spartan fruit samples from trees interplanted in another orchard. Concentrations varied greatly in all varieties from year to year. In comparison with Cox, fruit calcium concentrations were higher for a given mean mass per apple in Crispin in all years and in Spartan for 4 of the 6 years at harvest. Concentrations of nitrogen, potassium, magnesium and phosphorus were lower in Crispin and Spartan than in Cox fruit at harvest in all years, but dry matter and sodium concentrations differed only in some years. Changes in concentrations during fruit growth were measured in 2 years for each comparison. Differences between nitrogen, phosphorus and potassium concentrations in either Crispin or Spartan and Cox apples were evident throughout fruitlet enlargement in both years. Calcium concentrations were higher in Crispin and Spartan fruitlets than in Cox fruitlets of equivalent mass. Variations in the concentrations of potassium, magnesium and calcium from tree to tree were greater for Cox than Crispin samples but relationships between potassium and magnesium concentrations were similar for both varieties.
Nutritional composition of UK retail potatoes, both raw and cooked
Authors: Finglas Paul M. , Faulks Richard M.
Published: October 2006

Over two seasons, four maincrop potato cultivars together with early varieties, were purchased from a range of retail outlets in three principal consumer areas (London, Birmingham and Glasgow). Samples were analysed for moisture, total nitrogen, non‐protein nitrogen, fat, carbohydrates (sugars, starch and dietary fibre), vitamins and minerals. Analyses were carried out on both the raw and cooked (boiled, baked, roast and chipped) tubers every 12 weeks. Values for raw and cooked materials were compared with previously published figures, and cultivar, centre and seasonal effects were identified by analysis of variance. Nutrients found to be lower than the Food Composition Table data were riboflavin and niacin (50%), potassium (40%), iron, copper and zinc (20–30%); thiamin and total folate were 2–3 times higher, total ascorbate, initially similar, declined more rapidly after harvest. These differences were reflected in the values obtained for the cooked potato where the major difference was a reduction in the fat content of chips by about 40%. Cooking losses were similar to those in the Food Composition Tables. The main varietal effects were confined to the vitamins. Centre effects showed that potatoes from Glasgow had less ascorbate and dry matter but slightly more free sugars. The only significant seasonal effect was for total ascorbate where the second season was higher than the first.
The existence of the 1,2‐dicarbonyl compounds glyoxal, methyl glyoxal and diacetyl in autoxidised edible oils
Authors: Hirayama Teruhisa , Yamada Naohide , Nohara Motoshi , Fukui Shozo
Published: October 2006

The 1,2‐dicarbonyl compounds glyoxal, methyl glyoxal and diacetyl which are known to be mutagens without metabolic activation in the Salmonella typhimurium TA100 system, were detected in autoxidised edible oils (sesame, safflower and sardine oil). The method is based on the fact that the 1,2‐dicarbonyl compounds react with 4‐chloro‐1,2‐phenylenediamine to give 6‐chloroquinoxaline derivatives, which can be detected by 63Ni ECD‐gas chromatography. Glyoxal, methyl glyoxal and diacetyl were detected at 4.7, 7.0 and 1.6 μg g−1, respectively, in 20 h autoxidised methyl linolenate. Glyoxal, methyl glyoxal and diacetyl were also detected at 6.5, 7.0 and 3.1 μg g−1, respectively, in 30 h autoxidised sardine oil.
Cold setting alginate‐pectin mixed gels
Authors: Morris Victor J. , Chilvers Graham R.
Published: October 2006

Glucono‐delta‐lactone (GDL) has been used as a slow acidifier to produce cold setting mixed alginate‐pectin gels. Gelation was observed under conditions for which neither the alginate nor the pectin alone would gel. Gelation occurs after a lag phase. The effect of GDL on the gelation of the mixed system is discussed in terms of the buffering action of the polymers. Possible technological applications are briefly discussed.
Puffing characteristics of some processed rice stored in different packaging systems
Authors: Bhattacharjee Mridula , Nath Surya
Published: October 2006

Varietal differences in the puffing characteristics of parboiled rice (PABR), parboiled milled rice (PAMR) and milled rice (MR) after storage in polyethylene bags (PLY), polyethylene impregnated jute bags and jute bags (JUB) for varying times up to 120 days were studied. Monthly observations covering changes in physicochemical properties considered to have bearings on the puffing characteristics of rice were made and the factors responsible for puffing of rice have been tentatively identified. Better puffing followed increased ageing of rice samples. PABR was a better puffer than PAMR while MR yielded charred rice and hence was unsuitable for puffed rice production. Alkali degradation and grain hardness had some regulatory effect on the quality of puffing of rice. PLY emerged as the best packaging material for storing rice for later puffing. In JUB rapid damage of rice samples occurred owing to insect infestation and it was the poorest packaging unit.
High performance liquid chromatographic determination of soluble carbohydrates in commercial drinks
Authors: Vidal‐Valverde Concepción , Valverde Serafin , Martin‐Villa Carmen , Blanco Inmaculada , Rojas‐Hidalgo Enrique
Published: October 2006

High performance liquid chromatography was carried out to determine the soluble sugar content in canned soft drinks and commercial fruit juices stored in different types of containers. The total amount of sugars ranged from 9.2 to 13.5 g 100 ml−1 for the soft drinks, 10 to 14 g 100 ml−1 in fruit nectars and 3 g 100 ml−1 in tomato juice. The individual sugar content of soft drinks varied between different batches, although the total amount remained fairly constant for each kind of drink or juice. Only in tomato juice where sucrose was not present, did the values for glucose and fructose remain constant.
Influence of storage on the protein quality of pearl millet flour
Authors: Boora Pinky , Kapoor Amin C.
Published: October 2006

Whole grain flours of two cultivars of pearl millet (Pennisetum typhoides Rich) were stored in cans for 8 days at the prevailing room temperature (25±5°C), until the flours developed an off‐flavour and bad taste. The flour samples were then evaluated for protein quality. The values of protein efficiency ratio, true digestibility, biological value, net protein retention and protein utilisation fell markedly during storage. The protein quality of the cultivar with the higher amount of oil was affected more severely.
Inhibition of structural carbohydrate fermentation by forage phenolics
Authors: Jung Hans‐Joachim G.
Published: October 2006

The benzoic and cinnamic acids found in forages were tested for their inhibitory effects on digestion of cellulose and hemicellulose by mixed cultures of rumen microorganisms in vitro. Rate and extent of cellulose digestion with the addition of cinnamic acids were determined. The benzoic acids and aldehydes were also compared for their inhibitory potential. Of the benzoic acid derivatives, only the parent compound (benzoic acid) inhibited in vitro dry matter disappearance (IVDMD) of cellulose after 48 h, whereas most of the cinnamic acids were inhibitory. None of these compounds depressed IVDMD of hemicellulose. Extent of cellulose digestion was unaffected by cinnamic acids, but rate of digestion was significantly reduced. The ranking of compounds for inhibitory potential was essentially reversed between 48 and 168 h of fermentation as compared with the ranking for 0 to 48 h of fermentation. There were also shifts in the molar proportions of volatile fatty acids produced between these times. The rapid reduction in concentration of cinnamic acids by microbial fermentation may explain these shifts. Benzoic aldehydes were more inhibitory of structural carbohydrate fermentation than were acids. No clear relationship existed between addition of hydroxyl or methoxyl groups to benzoic or cinnamic acids and their depressing effects on IVDMD. Cinnamic acids, which are more abundant in forages, were more inhibitory than the benzoic acids; but for all compounds, it appeared that hemicellulolytic bacteria were generally more tolerant of these compounds than the cellulolytic bacteria.
Blocked thiols in glutenin and protein quality
Authors: Ewart John A. D.
Published: October 2006

It has already been suggested that when glutenin chains are synthesised, two cysteine residues on each chain preferentially form interchain disulphide bonds (SS) resulting in linear arrays of polypeptide chains. Presumably steric factors stop the growth of a molecule eventually, leaving each terminal chain with a free SH group. It is now postulated that the free SH groups later react with low molecular weight (mol. wt) thiols and SS compounds, which also break some interchain bonds by SS interchange so reducing the average mol. wt of the glutenin. Terminal SH groups and the halves of each broken SS become blocked by low mol. wt compounds. Therefore, if the quantity of glutenin‐bound low mol. wt thiols (end‐blockers) bound to glutenin could be measured it would enable the number of glutenin molecules to be calculated and hence a number‐average mol. wt. When six wheats spanning the normal range of baking quality were tested, glutenin‐bound half‐cystine and glutathione residues were eventually found, but no SH groups could be detected. The number‐average number of chains per glutenin molecule (proportional to mol. wt) was correlated with intrinsic viscosity of glutenin and with loaf volume per gram of loaf protein, thus supporting the hypothesis. It is suggested that the main aim of reducing the native thiol content of flour with improvers is to limit degradation of glutenin molecules. If the hypothesis should be confirmed it may be advantageous to breed wheats with low contents of thiols and active disulphides in the grain, since their quantities may largely account for glutenin mol. wt and, in turn, protein quality.
Effects of single and multiple waterloggings on the growth and yield of winter wheat on a clay soil
Authors: Belford Robert K. , Cannell Robert Q. , Thomson Robert J.
Published: October 2006

The response of winter wheat to surface waterlogging in monoliths of clay soil in lysimeters was studied. The treatments, selected as corresponding to the most extreme likely in Britain, were: 5 days of waterlogging in October between germination and emergence; 42 days of waterlogging during tillering in January and February; and 21 days from mid‐April during stem elongation. These treatments were used singly and in all combinations and were compared with a freely‐drained control. During waterlogging, the oxygen concentration in the soil declined most rapidly when the soil was warmer (in October and April) and at the shallower depths (5, 20cm): also, a decrease in soil solution nitrate was accompanied by an increase in nitrous oxide evolution. Pre‐emergence waterlogging restricted plant population to 35 m−2 compared to 338 m−2 under free drainage. Subsequently, compensatory growth resulted from diminished interplant competition for nitrogen, water and light: a greater proportion of tillers survived and the flag leaves were larger, although ears at harvest were fewer in all treatments waterlogged before emergence. After waterlogging during tillering, grain loss was accounted for entirely by a decrease in the number of ear‐bearing tillers. After waterlogging during stem elongation, yield losses were associated primarily with fewer grains per spikelet. Grain yield was depressed by about 4–12% after single waterloggings, by 20% after any two waterloggings, and by 32% when plants were waterlogged on all three occasions.
A critical investigation of a number of different methods of lipid determination in fish meal, with particular emphasis on corrections required in these determinations
Authors: De Koning Adrianus J. , Evans Anna Alida , Heydenrych Christine , De V. Purcell Christopher J. , Wessels Jacobus P. H.
Published: October 2006

A critical study was made of a number of lipid extraction methods on stabilised brown fish meals and on white fish meal. By analysing the lipids it was shown that in all procedures proteinaceous material was extracted and an attempt was made to correct for this non‐lipid material. On the basis of the results obtained it seemed that the Bligh and Dyer method gave the highest yield of lipid. In addition it was found that the EEC procedure needed the application of a correction factor to account for the losses sustained in the hydrolysis step.
Stabilisation of protein and oil in fish silage for use as a ruminant feed supplement
Authors: Haard Norman F. , Kariel Nancy , Herzberg Gene , Feltham L. A. Woodrow , Winter Karl
Published: October 2006

Fish silage was prepared from 96.5% offal obtained from Atlantic cod fillet processing and 3.5% (by wt) formic acid. The fish silage became an homogeneous liquid of low viscosity in 36–58 h at 20°C; however, the oil and protein components continued to be hydrolysed for several months. Addition of formaldehyde to fish silage (0.25 or 0.39% by wt) after liquefaction was complete, served to prevent continued protein hydrolysis and oxidative rancidity of the oil. It also decreased the development of ‘off‐odours’, and the formation of total volatile bases. Fish silage was readily absorbed by hay at a ratio of 1.5 parts silage to 1.0 parts hay by weight; the product is referred to as ‘haylage’. Voluntary intake by wethers of ‘haylage’ prepared from de‐oiled, formaldehyde‐treated fish silage was better than for ‘haylage’ prepared from untreated fish silage. The crude protein content of ‘haylage’ rations was more than satisfactory for fattening lambs, although the energy content of ‘haylage’ rations may be a limiting factor. Retention of fish oil in the silage to increase the energy content of rations was unsuccessful because voluntary feed intake was depressed. The addition of formaldehyde to fish silage is advantageous when the product is to be fed to ruminant livestock since protein and lipid degradation in the feed, and also possibly in the rumen, are minimised and voluntary intake of ‘haylage’ by sheep is increased.
Determination of the glycoalkaloid content of potato tubers by three methods including enzyme‐linked immunosorbent assay
Authors: Morgan Michael R. A. , Coxon David T. , Bramham Sara , Chan Henry W‐S. , Van Gelder Win M. J. , Allison Michael J.
Published: October 2006

Potato tuber samples of diverse genetic backgrounds were analysed independently for total glycoalkaloid content by three different procedures. Two of the methods used were conventional chemical assays, the third an enzyme‐linked immunosorbent assay (ELISA). Agreement between all three was extremely good, though the ELISA employed much simpler sample preparation, was technically easier to carry out, and could assay more rapidly large numbers of samples. For these and other reasons, the ELISA will find wider application in future.
Varietal differences of extracts from blackcurrant buds (Ribes nigrum L.)
Authors: Kerslake Mark F. , Menary Robert C.
Published: October 2006

Examination of the volatile constituents of blackcurrants (Ribes nigrum L.) was undertaken to examine differences in varietal extracts. The compositions of extracts from 10 cultivars grown in southern Tasmania were determined by gas chroma‐tography and mass spectrometry. The patterns of association of the 34 components measured were analysed by principal co‐ordinate analysis, the co‐ordinates being plotted in four dimensions. A close association between oils extracted from selections belonging firstly to the Goliath and Baldwin groups, and secondly to the Boskoop and French groups, has been revealed. This analysis confirms the relationships proposed by Todd in his phenotypic key for identification. The results are discussed in the light of previously distinguished monoterpene and sesquiterpene phenotypes.
The effects of harvest maturity, ripeness and storage on kiwifruit aroma
Authors: Young Harry , Paterson Vivienne J.
Published: October 2006

Quantitative gas chromatographic analysis of the volatile aroma components has been used as an objective measure of the effects of maturity at harvest, ripeness and storage on the aroma volatiles of kiwifruit. Increasing ripeness is associated with a rapid increase in the levels of aroma volatiles, especially esters, while increasing storage time prior to ripening is accompanied by a decrease in the amount of aroma volatiles.
The effect of cooking conditions on the formation of volatile heterocyclic compounds in pork
Authors: Mottram Donald S.
Published: October 2006

Headspace volatiles from grilled, roast and boiled pork were entrained on Tenax GC and analysed by combined gas chromatography‐mass spectrometry. Well‐done grilled pork contained 66 heterocyclic compounds including pyrazines. thiazoles, thiophenes, furans and pyrroles, many of which had not previously been found in cooked pork. The pyrazines accounted for almost 80% of the total headspace volatiles, although most of the other heterocyclic compounds were present only in small amounts. Pork cooked by less severe grilling or by roasting or boiling contained considerably fewer heterocyclic compounds, and headspace volatiles were dominated by aldehydes and alcohols originating from thermal oxidation of lipid.
Estimation of biogenic amines in foods
Authors: Ingles David L. , Back Joan F. , Gallimore David , Tindale Ross , Shaw Kevin J.
Published: October 2006

Biogenic amines in foods have been proposed as initiators of dietary‐induced migraine. Studies of levels of 2‐phenylethylamine, p‐tyramine and the diamines histamine, putrescine and cadaverine in a number of Australian and other foods were made by ion exchange and high pressure liquid chromatographic methods. In the latter method the amines were chromatographed as their fluorescamine derivatives. The use of such derivatives also enabled confirmation of the identity of the amine by field desorption‐mass spectrometry. Extraction procedures were devised to give satisfactory recoveries of amines in foods and to overcome problems associated with the binding of amines to other food constituents.
On the fractional melting of milk fat and the properties of the fractions
Authors: Banks William , Clapperton John L. , Girdler Anne K.
Published: October 2006

Standard methods of fractionating milk fat from the melt produce solid fractions that exhibit melting at temperatures considerably lower than that used for the fractionation. The use of high concentrations of aqueous detergent, in the presence of ammonia as an aid to centrifugation, has resulted in this solid material being sub‐fractionated into a semi‐solid, plastic material and a crystalline solid. The technique may be applied directly to milk fat to produce three fractions at a given fractionation temperature. Fatty acid compositions and separations according to triglyceride number are recorded for the parent fats and their fractions. Melting fingerprints, obtained by differential scanning calorimetry, are shown for the various samples, and the heats of melting are discussed.
Polycyclic aromatic hydrocarbons and lead in roadside lettuce and rye grain
Authors: Larsson Bonny K.
Published: October 2006

Thirty‐eight samples of lettuce and three samples of rye from an experimental site close to a highway were analysed for 20 polycyclic aromatic hydrocarbons (PAH) and lead. The lettuce plants were grown 8–65 m from the road and collected after 5,9 and 11 weeks of exposure. The levels of benzo[a]pyrene (BaP) and lead varied from 0.1 to 1.3 μg kg−1 and from 0.18 to 1.6 mg kg−1, respectively. The plants grown close to the road and with long exposure times showed the highest levels. The positive gradients for PAH and lead with exposure time and closeness to the road were nearly identical, but in different concentration ranges. Lettuce plants grown in a cold frame showed lower levels than those grown in the open. In rye sampled at 7–25 m from the road, BaP was not detected and lead levels ranged from 0.07 to 0.11 mg kg−1. The results suggest that the Swedish National Food Administration/National Environmental Protection Board recommendations, i.e. not to grow leafy vegetables closer than 25 m from roads with intense traffic, are sufficient at traffic flows of up to 12 000 vehicles per day.
Ion exchange and adsorbent resins for removal of acids and bitter principles from citrus juices
Authors: Johnson Robert L. , Chandler Bruce V.
Published: October 2006

A further 20 commercially available ion exchange and adsorbent resins were screened for their affinities for titratable acid and citrus bitter principles. Two anion exchange resins offer the prospect of simultaneous acid reduction and debittering; two cation exchange and five adsorbent resins were moderate to powerful adsorbers of the bitter principles. The food regulation status of these resins is discussed.
Post‐harvest changes in fermentable sugars in sweet Sorghum (Sorghum bicolor cv. Wray)
Authors: Hansen Ross W. , Ferraris Robert
Published: October 2006

Changes in sucrose and reducing sugar content of Sorghum bicolor (cv. Wray) were followed for 72 h after harvest to gauge the stability of the sugars between harvesting and milling and to devise suitable sampling procedures for analysis. Within the first 48 h, sucrose decreased from 34 to 19% of the dry matter while production of monosaccharides increased correspondingly from 9 to 23% of the dry matter. Processing of sorghum stems within 24 h of harvest will retain maximum sucrose content. This is necessary for commercial sugar production or when a knowledge of sugar composition at harvest is required. Beyond 24 h, inversion to reducing sugars is significant and may render the crop more suitable for use as an industrial feedstock (e.g. for liquid fuel production).
A simple method for determining the shear modulus of food dispersions and gels
Authors: Ring Stephen G. , Stainsby George
Published: October 2006

The application of a simple commercially available apparatus to the measurement of the dynamic shear modulus for viscoelastic food dispersions and gels is described. For vibrant gels the shear modulus can be determined to a precision of ±5% in the range 50 to 5 × 105 Nm−2 and the value is independent of the frequency as the gel behaves like a simple elastic solid. The measurement causes minimal mechanical disturbance to a gel or dispersion and is thus ideally suited for monitoring weak network structures. With weak or “dead” gels, or pastes, the dynamic modulus at just one frequency, 200 Hz, is found.
Partitioning into maize grain N fractions of N absorbed through the roots before and after pollination
Authors: Rendig Victor V. , Crawford Thomas W.
Published: October 2006

The abundance of N in various fractions in maize (Zea mays L.) grain was compared in two genotypes, a normal hybrid (Pioneer 3369A) and its opaque‐2 (o‐2) counterpart (L3369). Plants were grown in the greenhouse in sand cultures irrigated daily with nutrient solutions containing 3.75mM N as NO3 ion. At anthesis the plant cultures were divided into sets, one set continuing to be irrigated with the same solution, but with 15N added, and the other set irrigated with a solution of the same composition except that the N was omitted. The plants were sampled at 12, 24 and 36 days after pollination. Post‐anthesis N nutrition affected the composition of the vegetative growth but had no effect during the sampling period on yields or amounts of N in the grain. At 12 days post‐pollination there were no differences between the two genotypes in N partitioning, with about 50% of the N present as nonprotein N (NPN). At 24 and 36 days over 75% more N was present as zein in the normal genotype as in the 0‐2, while the latter contained a much higher proportion of N as NPN. The albumin‐globulin and glutelin fractions were slightly greater in the o‐2. The N absorbed after pollination was partitioned among the grain protein fractions similarly to N absorbed prior to pollination. The nature of the NPN fraction needs to be considered in evaluating effects on crop quality of an elevated N supply.
The amylose and lipid contents, dimensions, and gelatinisation characteristics of some wheat starches and their A‐ and B‐granule fractions
Authors: Soulaka Amjad B. , Morrison William R.
Published: October 2006

Starches isolated from 23 bread wheats (Triticum aestivum) and 26 durum wheats (T. durum) contained 26.3‐30.6% (mean 29.1%) total amylose, 19.3–25.1% (mean 22.9%) apparent amylose and 783–1144mg 100g−1 (mean 977 mg 100g−1) lysophos‐pholipids. Gelatinisation temperatures were 57.3–64.9°C (mean 61.8°C) and enthalpies 6.4–11.8 Jg−1 (mean 9.7Jg−1) in excess water, measured by differential scanning calorimetry. There were no correlations between any of these parameters. Starch granule size distributions were determined with a Coulter Counter and 100–channel analyser. A‐granule mean volumes were 1235–2585μm3 (av. 1778), modal volumes 863–1804μm3 (av. 1264), mean diameters 13.9–16.0μm (av. 13.99), and specific surface areas 0.236–0.302m2g−1. B‐granule mean volumes were 35.4–100.4μm3 (av. 55.9), modal volumes 16.5–54.5μm3 (av. 27.7), mean diameters 3.66–5.07μm (av. 4.09), and specific surface areas 0.684–0.920m2g−1. The B‐granule contents of the starches were 12.8–34.6% (av. 27.3) by weight (sedimentation method) and 13.0–37.3% (av. 24.0) by volume (Coulter method), the latter being the more accurate method.
Chemical composition and in vitro degradability of major chemical constituents in botanical fractions of red clover harvested at different stages of maturity
Authors: Åman Per
Published: October 2006

Red clover was harvested at five different stages of maturity during primary growth and separated into leaves, petioles, stems and flowers. The contents of extractives, crude protein, starch, non‐starch polysaccharides, and non‐starch polysaccharide constituents, and the in vitro degradability, were determined in the botanical fractions. Chemical analysis of the in vitro residues revealed that the degradability of crude protein was around 80% in all fractions at all harvest times whereas in most cases the degradability of non‐starch polysaccharides and non‐starch polysaccharide residues was highest in the leaf fractions, intermediate in the petiole fractions and lowest in the stem fractions, with only small changes occurring due to development and maturation during the investigated period. Glucose and xylose were the least degraded non‐starch polysaccharide residues in all fractions.
Structure and functioning of water‐storing agricultural polyacrylamides
Authors: Johnson Michael S. , Veltkamp Cornelis J.
Published: October 2006

New polyacrylamides have been developed to improve the storage capability and the efficiency by which plants use water in agriculture and horticulture. These products are particularly useful where water is scarce or expensive and where drought is a significant hazard in crop production. However, there is considerable variation in the water absorption and release capabilities of different products that is explained by manufacturing conditions. Scanning electron microscopy shows that high performance products have a cellular structure in the expanded condition, with plant‐available moisture stored both in enclosed vacuoles and within the polymer framework. The bridges that comprise the structure of the gel control water release under drying conditions and optimise recovery of the stored water by plants.
Structure of soya glycinin and conglycinin gels
Authors: Hermansson Anne‐Marie
Published: October 2006

Gels of glycinin and conglycinin formed at various heating temperatures, in the absence and presence of 0.2M sodium chloride were characterised by transmission electron microscopy. In distilled water both proteins formed gels consisting of strands with a thickness of 10–15 nm. The strands of glycinin were very regular and cross sections of strands showed a hollow cylindrical structure. In the presence of sodium chloride, glycinin formed an aggregated gel structure at 85°C, but at 95°C an ordered strand structure was formed. Dissociation of the quaternary structure on heating and reassociation of subunits into regular strands were considered the most probable mechanisms for strand formation from glycinin. The aggregated structure at 85°C was interpreted as a transient state prior to dissociation. Conglycinin rich gels were less regular and more crosslinked than gels of glycinin. Also, the strands of conglycinin showed a complex mode of aggregation possibly in the form of double spirals. The addition of sodium chloride caused a denser and more aggregated structure at 75 and 85°C, but the effects were not as drastic as in the case of glycinin. Heating temperature had only minor effects on the gel structure in the range studied.
The aroma of grapes. Localisation and evolution of free and bound fractions of some grape aroma components c.v. Muscat during first development and maturation
Authors: Gunata Yusuf Z. , Bayonove Claude L. , Baumes Raymond L. , Cordonnier Robert E.
Published: October 2006

The localisation of some aroma components in the different parts of the berry of Muscat grape varieties was studied. The evolution of these compounds was also monitored during the development and maturation of the fruit. The aromatic substances were certain terpenols in free and glycosidically bound forms and certain aromatic alcohols, benzyl and 2‐phenyl ethyl alcohols. The skin was the richest in free and bound terpenols in the berry. The ratio of bound free terpenols in skin, pulp and juice was similar. Free terpenols (in particular geraniol and nerol) were much more abundant in skin than in juice. It was possible to distinguish between the two Muscat varieties studied here using their levels of bound terpenols. These were abundant from the green stage of the grape berry onwards; their levels increased during development of the fruit to reach very high levels at the end of maturation. The bound terpenols have a considerable aroma potential, mainly located in grape skins, which it would be interesting to make use of in new wine technology.
Biochemical and microbiological studies on kawal, a meat substitute derived by fermentation of cassia obtusifolia leaves
Authors: Dirar Hamid A. , Harper David B. , Collins Martin A.
Published: October 2006

Biochemical and microbiological changes during the fermentation of leaves of the tropical legume, Cassia obtusifolia, in the preparation of the traditional Sudanese food, kawal, are reported. The microflora during fermentation were dominated by two bacteria, Bacillus subtilis and Propionibacterium sp. Other species present included Lactobacillus plantarum, Staphylococcus sciuri and two yeasts. No marked inter‐special successional pattern was observed during fermentation. Sun‐dried kawal possessed a mean crude protein content of 26.2% indicating negligible loss of N during fermentation. The overall chemical score of kawal protein was 73 with lysine as the most limiting amino acid. The main fermentation products were volatile fatty acids (VFA) principally n‐butyric and acetic acids although propionic and isobutyric acids were also present. Total VFA content averaged 15% at the end of fermentation but fell to 10% during sun‐drying. Lactic acid concentrations remained low throughout fermentation, the final product containing only 0.2% of this compound. Accumulation of ammonia‐N closely paralleled VFA formation and similarly declined sharply in concentration during sun‐drying. The major alcohols formed during fermentation were n‐propanol and n‐butanol which attained a maximum combined concentration of 3% although disappearing during the drying process. The insignificant change in pH during fermentation was ascribed to the buffering effect of the high calcium content of the leaves. Changes in chemical composition noted during sun‐drying indicated that this process involved not only dehydration but secondary microbial action.
Trace element concentrations in winter cereals under intensive cultivation
Authors: Dickson E. Leslie , Christie Peter
Published: October 2006

Winter wheat and barley shoots sampled at the tillering stage from 12 farms in two intensive cereal production areas of Northern Ireland were analysed for trace elements B, Co, Cu, Fe, Mn, Mo and Zn plus Ca and Mg. Soil pH values were also determined for each field. Shoot concentrations of all elements were normal except for five fields of winter wheat which initially showed low Mn concentrations but exhibited normal levels when re‐sampled 5 weeks later. None of the plants showed deficiency symptoms for any element. Significant correlations were found between shoot concentrations of some nutrients and soil pH and their significance is discussed.
Estimation of moisture in undried wheat and barley by near infrared reflectance
Authors: Downey Gerard
Published: October 2006

The potential of near infrared reflectance spectroscopy for estimating moisture in undried wheat and barley was investigated. Calibrations were developed for use with wholegrain (13–20% moisture) and coarsely‐ground grain (13–26% moisture) for both grain types. The performance (accuracy and precision) during the 1983 harvest of the calibrations involving coarsely‐ground grain (13–26% moisture) was superior to that of three moisture meters currently in commercial use in Ireland.
Some characteristics and a comparison 6f the activities of o‐dihydroxyphenoloxidase activity from five yam (Dioscorea spp.) species
Authors: Ozo Ozo N. , Caygill John C.
Published: October 2006

o‐Dihydroxyphenoloxidase (E.C. 1.14.18.1) (o‐DPOase) was extracted from acetone‐extracted freeze‐dried yam tubers, and fractionated by (NH4)2SO4 precipitation and chromatography on DEAE‐cellulose to give two forms from Dioscorea alta L. (cv. UM680) and three forms from D. rotundata Poir. (cv. Nwopoke). Polyacrylamide gel electrophoresis revealed one of the forms from each species to contain two protein bands with o‐DPOase activity. o‐DPOase from D. alata showed activity with catechol, (+)‐catechin, (−)‐epicatechin and chlorogenic acid, but not with tyrosine, as substrate, o‐DPOase from D. rotundata showed activity only with catechol and (+)‐catechin. Km values for D. rotundata enzymes, calculated assuming a two‐substrate reaction, were between 0.2 and 0.8 mM for oxygen and 70 and 120 mM for catechol. The enzyme was most active between pH 5.5 and pH 7.0, and showed slight activation after holding for 2 minutes at 40 or 50°C. After heating to above 60°C the enzyme showed evidence of irreversible denaturation. Theo‐DPOase activity extracted from ten cultivars of five species of D. alata L., D. bulbifera L., D. cayenensis Lam., D. dumetorum Pax, and D. rotundata Poir. were compared.
An improved enzymic method for the determination of native and modified starch
Authors: Karkalas John
Published: October 2006

An improved method for the determination of starch by sequential hydrolysis with thermostable bacterial α‐amylase and fungal amyloglucosidase is described. Glucose was determined colorimetrically by a glucose oxidase‐peroxidase‐chromogen system at pH 7. Native normal and waxy starches, and distarch phosphate, gave quantitative yields of glucose with a high degree of precision (coefficient of variation less than 1%). Acetylated distarch phosphate, high‐amylose starch and retrograded amylose were initially treated with 1M NaOH for 30 min, then neutralised and analysed successfully as normal starch. Oxidised starch did not give a quantitative yield of glucose because of the presence of dicarboxylic groups in the polymer. For samples containing normal and waxy starch the analysis was carried out in about 4 h. The method was applied to a range of starch‐containing foodstuffs and the results are reported.
Relationship between the acid and limonin content of Washington Navel orange juices
Authors: Rodrigo M. Isabel , Mallent Dolors , Casas Andres
Published: October 2006

Juice samples of Washington Navel oranges from three groves were analysed for limonin, °Brix and acid during several seasons. A strong correlation between limonin and acid content has been found.
Influence of neutral detergent fibre and protein in Bengal Gram (Cicer arietinum) on the utilisation of proteins by albino rats
Authors: Radha V. , Geervani P.
Published: October 2006

The influence of neutral detergent fibre from Bengal gram on the utilisation of protein in albino rats was studied. Four market samples of Bengal gram and Bengal gram Annegeri variety harvested at three different stages of maturity were used for the study. The legumes were first analysed for proximate principles and then used as the source of nitrogen and fibre in the rat diets. Their proximate composition was similar to the values reported in literature. The content of neutral detergent fibre increased with increasing crude fibre. Growth of weanling rats was assessed on the basis of protein efficiency ratio (PER). Digestibility coefficient (DC), biological value (BV), total nitrogen retention (TNR) and net protein utilisation (NPU) were determined. PER, NPU, DC and nitrogen retention decreased with increase in fibre content in the diet. PER of Bengal gram sample with 14% neutral detergent fibre (NDF) was significantly different from the PER of all other samples. Biological value, however, was not affected by the fibre content.
A comparison of the non‐starch carbohydrates in cereal grains
Authors: Henry Robert J.
Published: October 2006

The carbohydrates soluble in 80% ethanol and in water at 100°C were extracted from two varieties of wheat, barley, oats, rye, triticale, rice and malt. The highest concentrations of sugars soluble in 80% ethanol were found in malt and rye with the lowest in rice. Barley contained the most raffinose and rye contained the most fructan. Rye had the highest levels of water‐soluble and total pentosans and barley the highest levels of water‐soluble and total (1→3), (1→4)‐β‐glucans. The total arabinose:xylose ratio varied from 1.2 in wheat and triticale to 0.3 in oats. All were very low in uronic acids.
A chemical study of Balanites aegyptiaca L. (Lalob) fruits grown in Sudan
Authors: Nour Abdel‐Azim A. M. , Ahmed Abdel‐Halim R. , Abdel‐Gayoum Abdel‐Gayoum A.
Published: October 2006

Two samples of Balanites aegyptiaca fruits were collected from two different regions in Sudan. The edible mesocarp contained 1.2–1.5% protein and 35–37% total sugars of which 81.3–91.1% is present as reducing sugars. The kernels contained 45.0–46.1% oil. Palmitic, stearic, oleic and linoleic acids were the main fatty acids. The ratio of saturated to unsaturated fatty acids was 10:26 in both samples. The protein was found to be low in aromatic amino acids.
Spectral evaluation of total phenolic components in Vitis vinifera: Grapes and wines
Authors: Somers T. Chris , Ziemelis Guntis
Published: October 2006

Whereas high levels of flavonoid extractives are responsible for the characteristic λDmax at about 280 nm in the ultra‐violet spectra of red wines, there is wide variability in the spectral features of natural white wines, in which the phenolic content is often minimal. For the latter, λDmax may occur anywhere within the range 265–285nm, with relatively strong absorbance at 320 nm arising from the presence of hydroxycinnamate esters. Massive fining of many white wines and juices with polyvinylpyrrolidone (10% w/v) has shown residual non‐phenolic u.v. absorbing constituents to be sufficiently uniform to enable direct spectral measurement of total hydroxycinnamates in white juices, white wines and rosés as (E320‐1.4) absorbance units. For white grape juices and white wines, total hydroxycinnamates are directly quantitated as mg litre−1 ‘caffeic acid equivalents’ and total flavonoid extractives may also be estimated. Total phenolic components of red wines are accounted as (E280‐4) absorbance units. The spectral interpretations enable comparative estimation of flavonoid extractives in all natural wine types.
The effect of food stuffs commonly consumed in egypt on iron absorption and utilisation
Authors: El‐Shobaki Fawzi , Saleh Nadia
Published: October 2006

The absorption and utilisation of iron in rats fed stewed beans, lentils, fenugreek and wheat bread were measured and compared with that of rats fed on casein. The results showed that 59Fe absorption and utilisation were better on the casein diet. Fenugreek promoted absorption and utilisation of iron relative to other food commodities. Stewed beans inhibited both absorption and utilisation of iron. Lentils, in spite of retarding iron absorption, assisted the utilisation. Amino acids and phytate phosphorus content of these ingredients are thought to play a part.
Identification of the species of origin of fresh, cooked and canned meat and meat products using antisera to thermostable muscle antigens by ouchterlony's double diffusion test
Authors: Kang'ethe Erastus K. , Gathuma Joseph M. , Lindqvist Kaare J.
Published: October 2006

Antisera to thermostable muscle antigens (TMA) from 14 species of bovidae were raised in goats and/or sheep. To achieve species specificity the antisera were absorbed with serum from the other species. While the absorbed antisera to TMA of buffalo, impala, eland, waterbuck, wildebeest and oryx were rendered specific, the antiserum to cattle TMA cross‐reacted with buffalo fresh meat antigens (FMA) and cooked meat antigens (CMA) but not with buffalo thermostable muscle antigens. Fresh and cooked muscle antigens from these two species could be differentiated by the antiserum to buffalo TMA. A similar approach was used to differentiate the FMA, CMA, and TMA of kongoni, topi and wildebeest. Antiserum to cattle TMA proved useful in detecting the presence of beef meat in meat products that had undergone commercial sterilisation.
The effect of plant development and environment on formononetin concentration in red clover (Trifolium pratense L.)
Authors: McMurray Cecil H. , Laidlaw A. Scott , McElroy Mary
Published: October 2006

Formononetin concentration in red clover herbage, determined by high performance liquid chromatography, was assessed in field, greenhouse and growth cabinet experiments. Formononetin content decreased in Hungaropoly swards from 5.6 mg g−1 DM when harvested in early May to 3.5 mg g−1 DM when harvested in mid‐June. In the regrowth the sward with the shortest regrowth period had the highest concentration content (6.8 mg g−1). In a pot experiment from vegetative through to the ‘dying inflorescence’ stage, formononetin concentration declined by 57% due to both a reduction in the concentration in stems more than in leaves and an increase in the proportion of stems in the dry matter. A temperature regime of 23/15°C (day/night) advanced flower appearance and adversely affected growth rate compared with 17/13°C. The lower temperature regime resulted in a higher formononetin content in expanded leaves (28% increase, mean of two harvests) and expanding leaves (17% increase). Incubation with β‐glucosidase increased the amount of formononetin extracted in the stems. Phosphate fertiliser reduced the concentration of formononetin, 96 kg P ha−1 reducing formononetin content by 32%, relative to red clover grown in soil with a low P content. The results are discussed in the context of the grazing management of red clover swards.
Correlation of theaflavins content and valuations of kenyan black teas
Authors: Owuor Philip O. , Reeves Stuart G. , Wanyoko John K.
Published: October 2006

Correlation between theaflavins content and tasters' valuations of Kenyan black teas generally give positive but statistically non‐significant correlation coefficients. In 105 correlations using 12 samples each, only eight analyses gave statistically significant (P⩽0.05) correlations. Theaflavins contributed positively towards valuations but Kenyan black plain teas have high and possibly above optimum theaflavins content. Consequently other factors appear to play major roles in tea pricing, for example the generally higher prices realised by Kenyan black plain teas compared to Malawi black plain teas can only be partly attributed to the higher theaflavins content of the Kenyan teas.
The oxidative stability of lard at −20°C: Evidence for a synergistic prooxidant effect of copper and curing salts
Authors: Coxon David T. , Peers Kenneth E. , Griffiths Nerys M. , Chan Henry W.‐S.
Published: October 2006

In connection with an interest in the problem of rancidity development in cold‐stored cured meat products (particularly bacon), the effect of certain trace components and permitted food additives on the oxidative stability of model systems containing lard was examined. Lard, to which additions of various single additives or combination of additives had been made, was stored for periods of up to 16 weeks at −20°C. Samples were removed during this time to assess the extent of their oxidation by chemical analysis (peroxide value determination) and sensory evaluation (odour). The additives studied included water, sodium chloride, sodium nitrate, sodium nitrite and copper (as palmitate, acetate and sulphate). It was observed that there was progressive oxidative deterioration of the lard with noticeable rancidity developing after 8 to 16 weeks' storage at −20°C when water, sodium chloride, sodium nitrate, sodium nitrite and copper were present in combination.