bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein self‐encapsulation: A mechanism involved with colloidal flocculation in citrus fruit extracts
Authors: Shomer Ilan
Published: October 2006

Cloud stability in citrus fruit aqueous peel extract (PEX) and the derived serum (SPEX) was studied with respect to endogenous coagulants and the possible involvement of soluble pectin as stabilising agent. Heat treatment of the pectin‐degraded SPEX induced the appearance of turbidity as a result of protein coagulation, particularly in the pH range of 3.5–4.5, whereas only slight coagulation occurred without heat treatment. The pectin in non‐degraded SPEX therefore inhibited heat coagulation of most of the protein present. Incubation of PEX itself with exogenous depolymerising pectinase (DP) slightly increased its transmittance, and subsequent heat treatment clarified the suspension within a short time, especially at pH 2.5–4.5. Under the electron microscope, heat‐coagulated proteins from DP‐incubated SPEX appeared as dispersed amorphous bodies showing two main types of pattern; the coagulate from a PEX preparation of high oil content appeared as ultramicro‐droplets of oil encapsulated within coagulated proteins.

The evidence indicates that soluble pectin in PEX preparations affects cloud stability by preventing the coagulation of heat‐denatured proteinaceous components; once the pectin is degraded by endogenous and exogenous DP, protein coagulation occurs rapidly on heat treatment, resulting in co‐precipitation of the other encapsulated colloidal bodies.
Preparation and characterisation of dietary fibre from sugar beet pulp
Authors: Michel Florence , Thibault Jean‐François , Barry Jean‐Luc , de Baynast Régis
Published: October 2006

Dried sugar beet pulp was ground and washed with 95% ethanol in order to obtain a colourless and odourless product which could be used as dietary fibre after drying and sieving. Sugar beet fibre had the same chemical composition as the initial pulp: 26–32% of hemicelluloses, 22–24% cellulose, 21.5–23% uronic acids, ∼1–2% lignin, ∼7–8% protein, 7.5–12% ash and ∼0.5% residual sucrose. The main physicochemical properties such as density, cation exchange capacity (∼0.6 meq g−1) and water holding capacity (24–32 g g−1) were determined. The water holding capacity of sugar beet fibre was only slightly affected by pH and ionic strength (adjusted by NaCl or CaCl2) but it held less water in the H+ form than in the salt form, Na+ or Ca2+.
Sorption of flavour compounds in aqueous solution into polyethylene film
Authors: Shimoda Mitsuya , Ikegami Tohru , Osajima Yutaka
Published: October 2006

Sorption of flavour compounds by the polyethylene (PE) liner of laminated pouches (PET/Al/PE) containing a flavour solution has been studied. The solution contained 43 volatile compounds (each 2 μl litre−1) in sugar ester solution (3 g litre−1). The distribution ratios of the flavour compounds for sorption into various PE liners increased with carbon chain length of the flavour compounds from 0.01 to 0.1 for alcohols, from 0.03 to 1.23 for aldehydes, from 0.02 to 5.77 for aliphatic esters and from 0.11 to 11.6 for benzoates. In each series (all straight‐chain compounds) the distribution ratios increased about threefold for each methylene group, but in the compounds composed of 11 or more carbon atoms the increment was less or negative. The distribution ratio for a given PE film was proportional to the film thickness. The distribution ratios increased with decreasing crystallinity of the PE film and the results for the films of different crystallinities suggested the existence of an impermeable boundary region surrounding the crystalline material amounting to about 20% of its volume.
Phenolic compounds in oak wood extracts used in the ageing of brandies
Authors: Puech Jean‐Louis
Published: October 2006

The oak wood extracts used in brandy production are extremely varied because of the different ways in which they are made: by infusion, by boiling or by maceration, with or without prior physical or chemical treatment of the wood. Such extracts release a large quantity of phenolic compounds and a very small amount of partially degraded lignin into the brandy, unlike spirits aged in oak barrels. Among monomer compounds derived from lignin, the presence of vanillic and syringic acids, vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde can be noted. In the wood extracts, phenolic compounds and aromatic acids frequently dominate the ligno‐complex and aromatic aldehydes respectively, which is not the case in brandies. Two samples of liquid extracts of oak wood displayed statistically aberrant vanillin contents.
Saponin composition of 13 varieties of legume seed using fast atom bombardment mass spectrometry
Authors: Price Keith R. , Eagles John , Fenwick G. Roger
Published: October 2006

A mass spectrometric technique is described which provides a fingerprint of the saponin composition in crude extracts of 13 varieties of bean seed. The identity of individual saponins was confirmed using HPLC. The ability of this technique to predict the presence of unidentified saponins and, hence, its use for monitoring fractionation or isolation procedures is discussed.
Nutritional evaluation of a protein concentrate and of carotenes derived from Dunaliella bardawil
Authors: Mokady Shoshana , Cogan Uri
Published: October 2006

The quality of the protein of the green alga Dunaliella bardawil was evaluated with rats and observed to have a protein efficiency ratio of 1.2. The protein was found to be limited by lysine, containing 70% of the optimum amount recommended for growing rats, only 60% of which was available. The carotenes of the alga were absorbed and recovered as retinol in the liver of rats, in a proportion similar to that of commercial β‐carotene.
Composition of the seeds of some Amaranthus species
Authors: Singhal Rekha S. , Kulkarni Pushpa R.
Published: October 2006

The seeds of the five commonly consumed Amaranthus species have been analysed for their chemical composition and starch characteristics. A notably high fat, protein and ash content in the seeds of a sample of A. teunifolious as compared with other species has been demonstrated. All the samples analysed had a high oxalate and phytic acid content. The size of the starch granules from all the samples was in the range 08.2.3μm and the circular shape of granules from all the species was strikingly similar. Amaranthus polygamous and A. gracilis had low amylose starches (111.7 and 97.1 g kg−1, respectively), and A. spinosus and A. teunifolious had appreciable proportions of amylose (166.7 and 245.0 g kg−1, respectively).
Changes in β‐glucan and other carbohydrate components of barley during malting
Authors: Henry Robert J.
Published: October 2006

Changes in total (1→3), (1→4)‐β‐glucan content were followed during the micro‐malting of nine varieties of barley with a wide range of malting qualities. These changes were related to estimates of endosperm modification based upon staining with Calcofluor. β‐Glucan content declined from an average of 3.54% in the barley to 0.75% in the malt. Pentosan and total starch (including starch‐derived oligosaccharides) levels showed comparatively little change during malting. β‐Glucan composition of the barley was a poor indicator of malting performance. However, the β‐glucan, starch and xylose contents of the malt all showed significant correlations with malt extract. Estimation of malt β‐glucan content gave the best indication of malt quality. Direct determination of β‐glucan may be of more value in assessing malt quality than indirect techniques based upon assessing modification of stained grains.
Comparative mutagenicity studies on fried minced beef, grilled sausage and grilled hamburgers
Authors: Abu‐Shakra Amal , Ioannides Costas , Walker Ronald
Published: October 2006

The mutagenicity of the basic fractions of fried beef patties, grilled hamburgers and grilled sausages was determined in the Ames test using activation systems (S9‐mix) derived from untreated and Aroclor‐pretreated rats and hamsters, and from rats pretreated with 3‐methylcholanthrene or phenobarbitone. In order to indicate whether the mutagenic activity was due to the presence of thermally generated amino imidazo aza‐arenes of the type previously identified in heated meat products (i.e. 2‐amino‐3‐methylimidazo[4,5‐f]quinoline (IQ), 2‐amino‐3,4‐dimethylimidazo‐[4,5‐f]quinoline (MeIQ) and 2‐amino‐3,8‐dimethylimidazo[4,5‐f]quin‐oxaline), these compounds were assayed under the same conditions. The mutagenicity of the basic fractions of the cooked foods and of the three aza‐arenes varied with the activation system used. The activation patterns of the basic fractions from fried beef and grilled sausages resembled that of IQ, whereas that of grilled hamburgers was more similar to that of MeIQ. Interestingly the total mutagenic activity of fried beef patties was greater than that of grilled hamburgers.
Chemical, nutritive, deoxynivalenol and zearalenone content of corn relative to the site of inoculation with different isolates of Fusarium graminearum
Authors: Hamilton Robert M. G. , Trenholm H. Locksley , Thompson Brian K.
Published: October 2006

Kernels from two samples of 18 ears of corn were hand‐shelled into three fractions (Fl, F2 and F3) relative to the site (F3) where the ears had previously been inoculated with one of four isolates of Fusarium graminearum (Schwabe). F3 and Fl were from the nearest and remotest parts of the ear, respectively, to the inoculation site. Ears of uninoculated control corn were processed in the same manner. The resulting 30 samples were analysed, after grinding (20 mesh), for deoxynivalenol (DON), zearalenone (ZEA), ergosterol (EGS), dry matter (DM), 200 kernel weight, Kjeldahl nitrogen (N), ether extract, ash, sugar, starch, acid and neutral detergent fibre (ADF, NDF, respectively), cellulose, hemicellulose and lignin. The true metabolisable energy (TME), TME corrected to zero N balance (TMEn), true available amino acid (TAAA) and true DM digestibility (TDMD) contents of these samples and corn to which 4, 16 or 64 mg purified DON kg−1 were added, were determined using adult White Leghorn chickens.

The DON, ZEA, EGS, N and ash contents were higher (P<0.001), and ether extract, TME and TMEn values were lower (p<0.01) in F3 than in Fl. Higer avilabilites accured for aspartic and glutamic acids, isoleucine, leucine and histidine in F2 and F3 than F1 (P<0.05). Carbohydrate and fibre values varied little (p>0.05) among fractions either within or among incoulation treatments. Sources of Fusarium inoculate influenced (P<0.05) the DON, ZEA, N, fat and TDMD of the corn. The TMEn and total TAAA of corn decreased (P<0.001) when purified DON was added. Moderate relationships (r=0.57−0.73) occurred between DON and ZEA, EGS and N. In general, these results are similar to those for wheat, and indicate that chemical and nutritive content of feedingstuffs may be increased when they are infected by toxigenic fungi.
Solvent extraction of alfalfa chloroplastic curds
Authors: Hernández Amelia , Gonzalez Gaspar , Martinez Carmen
Published: October 2006

The effects of pH during the preparation of chloroplastic curds upon the extraction of their lipids and their discoloration were studied. The chloroplastic curds were produced by means of a heat treatment, after adjusting the pH of the juice. Four pH values (6·0, 8·0, 8·5, 9·0) and three solvents (acetone, chloroform /methanol 2:1, propan‐2‐ol) were evaluated. The extractions were performed in a Soxhlet apparatus and carried out on freshly prepared curds. In the extracted and non‐extracted products, Kjeldahl nitrogen and the colour parameters a, b and L (Hunter Colour Difference method) were determined. The largest amount of lipids was extracted from the curds obtained at pH 6·0; this was associated with an increase in the nitrogen content of the concentrate arising from lipid removal. The curds obtained under alkaline conditions yielded increasing amounts of lipid with increasing pH. In all cases a slight decrease in the nitrogen content was noticed in the extracted curd compared with the non‐extracted curd. The colour of the extracted products depended both on the pH employed during curd preparation and on the solvent used for the extraction.
A time‐course study of glucosinolates in the ontogeny of forage rape (Brassica napus L)
Authors: Smith William H Macfarlane , Griffiths D Wynne
Published: October 2006

One cultivar and two breeding lines of forage rape, grown in a glasshouse, were sampled at weekly intervals from 9 to 22 weeks after sowing. Separate determinations of glucosinolate content were made on leaves and stems by HPLC. There were differences in the proportion and concentration of individual glucosinolates between the rapes and between leaves and stems, showing that levels of individual glucosinolates cannot be predicted from total glucosinolate content. Of particular interest was the variation with harvest date in the levels of individual glucosinolates. This has considerable implications for the comparison of levels of individual glucosinolates between cultivars and crops, and suggests that detailed agronomic field studies are required to determine whether the intake by animals of potentially toxic glucosinolates, in particular progoitrin, can be minimised by exploiting these seasonal differences in glucosinolate concentrations. Progress has been made in lowering the level of this glucosinolate, and the possibility of breeding forage rape with very low or zero levels of progoitrin is indicated.
Phenolic compounds in coffee pulp: Quantitative determination by HPLC
Authors: Ramirez‐Martinez Jose R
Published: October 2006

The content of phenolic compounds tentatively identified by HPLC in fresh coffee pulp gives an average composition in the 12 cultivars studied as follows: chlorogenic acid (5‐caffeoylquinic acid), 42·2%; epicatechin, 21·6%; isochlorogenic acid I, 5·7%; isochlorogenic acid II, 19·3%; isochlorogenic acid III, 4·4%; catechin, 2·2%; rutin, 2·1%; protocatechuic acid, 1·6%; and ferulic acid, 1·0%. When the percentages of chlorogenic and isochlorogenic acids are added to the corresponding one of epicatechin for each cultivar, it is found that they make up between 92·0% and 98·4% of the total of identified phenolic compounds. Qualitative or quantitative differences were not detected between cultivars of coffee plants resistant and susceptible to coffee leaf rust.
Production of toxic glucosinolate derivatives from rapeseed meal by intestinal microflora of rat and chicken
Authors: Nugon‐Baudon Lionelle , Szylit Odette , Raibaud Pierre
Published: October 2006

This work was based on a comparison between rats and chickens with different bacteriological status and fed rapeseed meal diets (DARMOR 00,39·0 % and 32·8%, respectively).

Results obtained with conventional vs axenic animals show that the rat intestinal microflora is responsible for the dramatic growth depression and for the slight hypertrophy of glucosinolate target organs (thyroid, liver, kidneys). Only a strong goitrogenic effect is seen with young conventional birds.

Chimera animal models (axenic animals inoculated with the whole faecal flora of another animal species) prove that the nature of the recipient host (rat) does not influence the expression of chicken intestinal microjlora in our experimental conditions. The rat whole faecal flora does not interfere with chicken growth rate, and thyroid hypertrophy is very moderate compared with conventional birds.

Finally, of the two molecules responsible for the goitrogenicity, one is destroyed by the feed irradiation required for axenic experiments.
Effect of cooking on nutrient content of tropical root crops from the south pacific
Authors: Bradbury J Howard , Bradshaw Kaye , Jealous Wayne , Holloway Warren D , Phimpisane Tony
Published: October 2006

The changes in nutrient content of sweet potato (Ipomoea batatas), taro (Colocasia esculenta), yam (Dioscorea alata) and cassava (Manihot esculenta) as a result of boiling, steaming and baking were determined. These changes were similar for all root crops (except in the case of sweet potato) and may be explained largely in terms of breakdown of nutrients with heat and in solubilisation of water‐soluble constituents. Major changes observed were (1) an approximate doubling of the apparent dietary fibre content due to formation on cooking of starch which was resistant to degradation by the enzymes used in the starch assay procedure; (2) a decrease in the content of potassium by up to one‐fifth and smaller decreases of other water‐soluble salts; (3) a very large increase in the maltose content of sweet potato on cooking, which did not occur with the other root crops.

In terms of human nutrition dry baking, generally speaking, appears to be the best method of cooking, followed by steaming, then boiling with retention of water and, finally, boiling with discarding of the water. However, in the particular cases of cassava and the edible aroids, which include taro, antinutritional factors may need to be removed by special cooking methods.
In vitro digestibility of protein and amino acids in protein mixtures
Authors: Brulé Danielle , Savoie Laurent
Published: October 2006

Six protein sources, casein, field peas, peanut meal, wheat flour, rapeseed and soya bean concentrate and their blends (ratio 1:1) were subjected to in vitro enzymic digestion. Wheat flour had the lowest in vitro digestibility (30% in 6 h) while the other sources had similar digestibilities (40%). Basic and aromatic amino acids were the most readily liberated from these protein sources. Some protein combinations, such as a rapeseed/field pea blend, gave in vitro digestibilities higher than calculated from individual proteins. The type of response observed could not be predicted from either nitrogen digestibility or amino acid composition of the individual sources. The digestibility of some amino acids was modified and this could be due to varying affinity of digestive enzymes for the protein.
Value of mesquite leaves as forage
Authors: Lyon Cameron K , Gumbmann Michael R , Becker Robert
Published: October 2006

The nutritive value of six species or cultivars of mesquite (Prosopis) was investigated: viz P alba, P articulata, P chilensis, P nigra, P velutina and cv ‘Ruby’. Chemical analyses indicated that all of these are suitable sources of forage. However, in vitro digestibilities are negatively correlated with the content of phenolic compounds. Species with high concentrations of phenolics (P alba and P chilensis) are significantly less digestible than other species with lower phenolic content. Toxicity of the phenolic components of P chilensis leaves was observed in feeding studies with weanling mice.
Influence of pretreatment on cooking quality parameters of dry food legumes
Authors: Singh K B , Erskine W , Robertson L D , And H Nakkoul , Williams P C
Published: October 2006

The effects of some pretreatment procedures on end‐use quality of food legumes commonly consumed in the Middle East were examined. Soaking reduced both the cooking time and its variation for all pulses tested. Soaking with NaHCO3 further decreased cooking time for chickpea and lentil but increased it for faba bean. In faba bean and lentil, but not in chickpea, the cooking times of dry and soaked seed were highly correlated. Dehulling also reduced cooking time in lentil. For preparation of the dish Hommos Bitehineh, whole chickpea of the desi type was inferior to the kabuli type but dehulling desi seed improved the quality of the product. Acceptability of Hommos Bi‐tehineh was uninfluenced by seed size but reduced by soaking in NaHCO3.
Degradation of cell wall material of apple and wheat bran by human faecal bacteria in vitro
Authors: Stevens Barry J H , Selvendran Robert R , Bayliss Catherine E , Turner R
Published: October 2006

The effect of the structures of plant cell walls and their component polymers on the degradability of dietary fibre by bacteria of the human colon was investigated by inoculating culture media containing cell wall materials of apple and wheat bran with slurries of human faeces which were then incubated for periods of up to 72 h. In the apple substrates the amounts of pectic polysaccharides were extensively depleted after 12 h, and after 24 h over 90% of the initial carbohydrate had been degraded. Material which remained after incubation was probably comprised of highly branched fragments of rhamnogalacturonans, cross‐linked by phenolics and proteins, highly branched fragments of cross‐linked xyloglucans, and degraded cellulose. In wheat bran the aleurone layer was preferentially degraded, but the glucuronoarabinoxylans, which were cross‐linked by phenolic groups, and the lignified outer layers of the bran were very resistant to attack. Bacteria adhered mainly to the broken or damaged surfaces of the plant cell walls, and in the more resistant tissues only penetrated the intercellular regions.
Inhibition of malolactic fermentation of wines by products of yeast metabolism
Authors: Lonvaud‐Funel Aline , Joyeux Annick , Desens Catherine
Published: October 2006

In addition to ethanol, the fermentation of grape must by yeasts produces fatty acids as secondary metabolites which inhibit growth of lactic acid bacteria. The degree of inhibition depends upon the fatty acid concentration and chain length and on the composition of the medium.
Preparation and properties of a white protein fraction in high yield from sugar beet (Beta vulgaris L) leaves
Authors: Merodio Carmen , Sabater Bartolomé
Published: October 2006

Chlorophyll‐free protein has been recovered at a yield in excess of 50 % from sugar beet (Beta vulgaris L) leaf juice after two successive pH treatments. This corresponds to about 60 kg of white protein per hectare. The main component of the final preparation is ribulose‐1,5‐bisphosphate carboxylase (EC 4.1.1.39). Compared with the unfractionated protein from leaf extracts, the white protein preparation has higher contents of tyrosine, threonine, glutamic acid and proline and lower ones of isoleucine, lysine (although still high: 76mg g−1) and glycine. The content of methionine is high (24mg g−1) probably as a result of the addition of sulphite during protein extraction. The white protein preparation has a low level of ether extractives (17mg g−1) and a moderate ash (52mg g−1) content. The white protein is rapidly degraded by pepsin, trypsin and pancreatic juice.
Oligosaccharide contents in the seeds of cultivated lupins
Authors: Trugo Luiz C , Almeida Debora C F , Gross Rainer
Published: October 2006

The contents of socrose and α‐galactosides of the seeds of 84 cultivated lupin samples were determined by high performance liquid chromatography (PHLC) and the data were correlated both with genotype and environment.
Tissue degradation, amino acid liberation and bacterial decomposition of bulk stored capelin
Authors: Aksnes Anders , Brekken Bjørn
Published: October 2006

Bulk stored capelin with high contents of feed in the gut is easily solubilised because of high proteolytic activity. The amino acids most quickly liberated are arginine, serine, histidine, leucine, lysine and tyrosine; glycine, aspartic acid and glutamic acid are liberated at a slower rate. Bacterial activity results in a rapid and considerable decrease in total amounts of tyrosine, lysine, serine, arginine and histidine. The main products formed by bacterial decomposition of lysine, histidine and arginine are cadaverine, histamine and putrescine, respectively. Storage of capelin in the presence of antibiotics increased the amounts of free amino acids and total amino acids. After 10 days' storage at 6°C, about 30% of the total amino acid content in fish treated with antibiotics were fee amino acids.
An evaluation of a method to differentiate the species of origin of meats on the basis of the contents of anserine, balenine and carnosine in skeletal muscle
Authors: Plowman Jeffrey E , Close Elizabeth A
Published: October 2006

The high performance liquid chromatographic method proposed by Carnegie for determining the species of origin of meats in cooked products has been evaluated. The dipeptides anserine, balenine (ophidine) and carnosine have been extracted from the skeletal muscle of animals in New Zealand and compared with results obtained in Australia. The presence of significant quantities of balenine in red deer meat is reported for the first time. Limitations of the method are discussed.
HPLC determination of vitamin A and vitamin D2 in South Pacific root crops
Authors: Singh U , Bradbury J H
Published: October 2006

An HPLC method was developed for the analysis of α‐carotene, β‐carotene, retinol and vitamin D2. Sweet potato Ipomoea batatas, taro Colocasia esculenta, taro Xanthosoma sagittifolium, giant taro Alocasia macrorrhiza, giant swamp taro Cyrtosperma chamissonis, yam Dioscorea alata and yam D esculenta contained no appreciable amounts of α‐carotene, retinol or vitamin D2 and the amounts of β‐carotene were equivalent to 0‐300 μg kg‐1 retinol in the fresh samples. This small amount, compared with the WHO/FAO adult RDA of 750 μg day‐1, and the virtual absence of vitamin A related eye diseases in the South Pacific region, demonstrates the adequacy of greens and fiuits, and fish coastal areas, in meeting the vitamin A requirement.
The effect of weather damage on wheat enzymes
Authors: Marsh Susan J , Annuk David , Ozsarac Nesrin , Fox David J
Published: October 2006

Sound (ungerminated) and germinated wheat kernals (cv Banks) were milled into wholemeal flours, and the activities of a range of enzymes important in baking were determined. Germination of the wheat gave increases in α‐amylase (EC 3.2.1.1), protease (azocaseinase), endo‐arabinoxylanase (EC 3.2.1.55), endo‐carboxymethylcellulase (EC 3.2.1.4) and β‐D‐glucopyranosidase (EC 3.2.1.21) activities, and a slight increase in activity was detected for β‐D‐xylopyranosidase (EC 3.2.1.37). β‐Amylase (EC 3.2.1.2) glutathione reductase (EC 1.6.2.4) and most of the glycosidase activities tested did not significantly increase on germination.
Effect of some phenolic carboxylic acids on cherimoya (Annona cherimolia) polyphenoloxidase activity
Authors: Martínez‐Cayuela Marina , Plata María C , Faus María J , Gil Angel
Published: October 2006

Aliphatic carboxylic acids did not affect cherimoya (Annona cherimolia Mill) epicarp polyphenoloxidase activity. Benzoic, isovanillic, cinnamic, p‐coumaric, salicylic and 3‐hydroxybenzoic acids inhibited the oxidation of catechol and the hydroxylation of tyramine catalysed by cherimoya epicarp polyphenoloxidase; caffeic and ferulic acids activated the oxidation of catechol; protocatechuic and syringic acids activated the hydroxylation of tyramine. The minimal structural requirement of a phenolic compound to be an inhibitor of cherimoya polyphenoloxidase was the association of a carboxylic group and a benzene nucleus. The inhibitory strength was greater when a conjugated double bond was located between the carboxylic group and the benzene nucleus. Replacement of more than one hydrogen in the aromatic nucleus by either hydroxyl or methoxyl groups decreased the effectiveness as inhibitors, and, in some cases, led to an activation of the two characteristic reactions of cherimoya epicarp polyphenoloxidase.
Theoretical principles for the indirect determination of the total glucosinolate content in rapeseed and meal quantifying the sulphur concentration via X‐ray fluorescence (X‐RF method)
Authors: Schnug Ewald , Haneklaus Silvia
Published: October 2006

The introduction of double low oilseed rape cultivars into common crop production will require the development of methods for a precise, rapid and simple determination of the total glucosinolate content in rapeseed. Recent methods are often inappropriate for plant breeding work, and also for the trade and oil mills in separating parcels of seed according to their glucosinolate contents. In contrast to the methods commonly used (chromatography, enzymic and colorimetric tests) an indirect method is described here which is based on the very close correlation between the total sulphur and glucosinolate content in rapeseed. The sulphur content of the samples can be determined precisely and non‐destructively by means of X‐ray fluorescence spectroscopy (X‐RF). This new method, which is suitable for rapeseed and meal, requires simple preparation of the seed samples by grinding and compressing. The whole analytical procedure (sample preparation and measurement) takes 2‐4 min. If necessary, moist seed samples can be quickly dried by microwave heating, because the method does not require intact glucosinolates. The steps of the X‐RF method are fairly insensitive to errors. The method shows an excellent repeatability (r = 1.9 μmol g−1) and reproducibility (R = 3.8 μmol g−1). The results obtained with this X‐RF method correlate closely with the conventional reference methods (r2 = 96‐99%).
Glucosinolate profiles of international rapeseed lines (Brassica napus and Brassica campestris)
Authors: Sang Joseph P , Salisbury Phillip A
Published: October 2006

Seed samples from a range of international rapeseed lines (Brassica napus L and B campestris L) were analysed for glucosinolate content using high performance liquid chromatography (HPLC). This analytical method provided a total profile consisting of eight different glucosinolates, including those used to define the Canola standard. The data indicated that broad categories of distinct glucosinolate profiles existed among the seed lines analysed. Indole glucosinolate content, expressed as a percentage of total glucosinolate content, was higher in the low glucosinolate lines of B napus. The actual contents of all eight glucosinolates in the seed were variable, particularly gluconapin, glucobrassicanapin and progoitrin. The importance of this HPLC procedure in facilitating selection for high or low contents of individual glucosinolates is discussed.
Enzymic modification of vegetable protein by a crude preparation from a strain of Bacillus licheniformis
Authors: Manachini Pier L , Fortina Maria G , Parini Carlo
Published: October 2006

Sunflower seed proteins are of interest for their functionality, and for their nutritional quality which arises from a balanced amino acid pattern and the absence of antinutritional factors (Jaya et a1 1981; Rossi et a1 1985). Furthermore, sunflower meal is readily available after the oil extraction process. This communication reports the results of a preliminary study carried out to evaluate the ability of a crude proteolytic enzyme preparation, obtained from a strain of Bacillus licheniformis isolated in this laboratory, to hydrolyse proteins of different source. In particular, sunflower protein concentrate was investigated. Factors affecting the extent of enzymic hydrolysis, such as substrate concentration, pH, temperature, and some characteristics of the hydrolysates obtained, were studied.
Extraction of aluminium from acid, strongly weathered fijian soils using M KCI: A comparison of methods of extraction and determination
Authors: Naidu Ravendra , Syers J Keith , Tillman Russell W , Lee Robert , Kirkman John H
Published: October 2006

A comparison was made of methods for the extraction and determination of exchangeable aluminium (Al3+) in acid, strongly weathered soils. The results showed large differences in the amounts of Al3+ in each soil, depending on the method of extraction and determination. This observation has important implications for the liming of acid soils because in recent years there has been an increasing tendency to base application rates on the amounts of exchangeable Al3+ in soils. It appears that the most suitable method of extracting Al3+ from acid, strongly weathered Fijian soils involves shaking the soils with M KCl for 2 × l‐h periods, followed by the determination of Al3+ using the oxine colorimetric procedure.
Retinol and carotene content of foods consumed in East Africa determined by high performance liquid chromatography
Authors: Pepping Freerk , Vencken Catherina M J , West Clive E
Published: October 2006

The vitamin A activity of a number of fresh and dried foods important in the diet of people in East Africa was determined by high performance liquid chromatography. The analytical results obtained were combined with data from the literature for inclusion in a comprehensive food table which has been used in a study on xerophthalmia in the United Republic of Tanzania. The importance of adopting standard procedures for reporting retinol and carotenoid values is discussed.
Fish species identification by fish muscle dry powder as reference material
Authors: Neti Girija , Rehbein Hartmut
Published: October 2006

A method for preparing dry powders from fish muscles is described. The muscle dry powders (MDP) were extracted with low ionic strength buffer and compared with sarcoplasmic extracts of raw muscles by isoelectric focusing on ultra‐thin layer (100 μm) polyacrylamide gels. The protein patterns of MDP extracts corresponded to the patterns of the acidic proteins of raw muscle extracts. Because of the species specificity of the patterns, MDP can be used as reference material for fish species identification.

The acidic proteins remained extractable after storage of MDP for several months at room temperature.
Volatile compounds produced in maiilard reactions involving glycine, ribose and phospholipid
Authors: Salter Linda J , Mottram Donald S , Whitfield Frank B
Published: October 2006

Previous studies suggest that phospholipid affects the production of volatile heterocyclic compounds during cooking by participating in the Maiilard reaction, and also plays an important role in the formation of the characteristic aroma of cooked meat. These effects can be mimicked using aqueous model systems. The identities of 109 volatile products of model Maillard reactions involving glycine and ribose, with and without phospholipid, have been investigated using gas chromatography‐mass spectrometry and the individual odours of these systems noted during sensory assessment of the effluent from the gas chromatograph. The incorporation of phospholipid increased the overall number of volatile compounds and variety of odours produced, as well as altering the nature of the dominant components and aromas.
Effect of pH on the activity of ryegrass Lolium multiflorum proteases
Authors: Heron Shirley J E , Edwards R Alun , Phillips Patricia
Published: October 2006

The effect of pH on plant protease activity was investigated using buffered, gamma‐irradiated aqueous extract of ryegrass Lolium multiflorum. Rapid protein breakdown occurred in the first few days but was followed by a longer period of reduced activity. The overall pH optimum for ryegrass proteases was between 5·0 and 7·0 but there was still considerable activity at the acid pH levels found, eg in silage. Proteolysis did not proceed to completion even when the pH was not inhibiting.
Studies on aflatoxin in rice: Description and evaluation of a new apparatus for the separation of husk from dehulled rice contaminated with aflatoxin
Authors: Nkama Iro , Muller Hans G
Published: October 2006

A simple apparatus and method developed for the separation of husk from dehulled (brown) rice contaminated with aflatoxin is described. The performance and efficiency of the apparatus was evaluated by passing a series of dehulled rice and husk mixtures through it. Subsequently the aflatoxin distribution in both rice and husk was determined. The range was 24 to 81% for aflatoxin B1 and 11 to 76 % for B2, depending on the rice grain category and variety. The study indicates that the apparatus can be used conveniently to separate husk from aflatoxin‐contaminated rice with a minimum hazard to personnel. It is therefore recommended for use particularly in developing countries, where laboratory test mills may not be available.
Unused fertiliser nitrogen in arable soils—its contribution to nitrate leaching
Authors: Macdonald Andrew J , Powlson David S , Poulton Paul R , Jenkinson David S
Published: October 2006

Nitrate present in arable soils in autumn is at risk to leaching during the following winter. To see whether unused nitrogen fertiliser was a major source of this nitrate, 15N‐labelled fertiliser was applied to 11 winter wheat crops at rates of between 47 and 234 kg N ha−1in spring. The experiments were on three contrasting soil types in south‐east England.

On average, 17′% of the N from spring‐applied labelled fertiliser remained in the 0–23 cm soil layer at harvest (range, 7–36%) but only a small proportion was in inorganic forms (ammonium + nitrate). This was never more than 5 kg N ha−1and averaged only 1·3% of the fertiliser N applied (range, 0·4–3·6 %). Between 79 and 98% of the inorganic N in soils at harvest was unlabelled, being derived from the mineralisation of organic N rather than from unused fertiliser. The amount of unlabelled N was much greater where wheat was grown after ploughing up grass or grass/clover leys than where it was grown in all‐arable rotations. When wheat was grown without N fertiliser, soil inorganic N content at harvest was no lower than in plots given fertiliser at rates up to 234 kg N ha−1.

This work indicates that, for soil growing winter wheat, almost all of the nitrate at risk to leaching over the winter period comes from mineralisation of organic N, not from unused fertiliser applied in spring. Consequently, even a drastic reduction in N fertiliser use would have little effect on nitrate leaching.
Changes in dry matter concentration gradients in stored apples
Authors: Perring Michael A
Published: October 2006

Longitudinal and transverse dry matter concentration gradients were measured in Cox's Orange Pippin apples at harvest and during storage. Dry matter concentration was higher at the calyx end of the fruit at harvest than in the central zone and at the stalk end. This difference was maintained as dry matter concentration in the whole fruit declined during cold storage. Dry matter concentration decreased from the peel to the core in median transverse slices at harvest but this gradient diminished during storage at 4°C in either air or 1·25%v/v O2. After 11 weeks' storage dry matter concentrations became generally lower in all zones of the air‐stored fruit than those in apples stored in 1·25% v/v O2, but transverse distribution patterns of dry matter were similar in apples in either regime throughout storage. Proportions of dry matter in the outer zones declined whilst those in the inner cortex and core increased. The relevance of these changes to the quality of stored apples is discussed.
The HMW glutenin subunit composition of Canadian wheat cultivars and their association with bread‐making quality
Authors: Lukow Odean M , Payne Peter I , Tkachuk Russell
Published: October 2006

The proteins of 70 Canadian‐grown wheat cultivars were fractionated by SDS‐PAGE to determine their HMW glutenin subunit composition. On the basis of previously established relationships between individual subunits and measures of bread‐making quality, Glu‐1 scores were calculated for 67 cultivars. The three cuhivars Chinook, Cypress and Supreza were found to contain novel HMW glutenin subunits previously uncatalogued. The Glu‐1 scores accounted for 59–69% of the variation in bread‐making quality of these cultivars whereas flour ash accounted for none. The implications of these results to wheat breeding programmes are discussed.
Evaluation of shortenings based on various palm oil products
Authors: Idris Nor Aini , Berger Kurt G , Ong Augustine S H
Published: October 2006

Several formulations based on blends of hydrogenated palm oil (MP 41·5°C) and palm stearin (IV 44) with other liquid oils, on direct blends of palm stearin with other liquid oils, and on 100% inter‐esterified palm olein, were used as feedstocks in shortening production. The shortenings were stored at 20°C over a period of one month. Physicochemical characteristics, creaming properties and baking performance of the shortenings were evaluated and compared with the best shortening on the market. Slip melting point of the shortenings ranged from 41·5 to 46·4°C. Palm‐cottonseed oil shortenings had higher solid fat contents at all temperatures than palm‐soya bean or palm‐low erucic acid rapeseed oil shortenings. The shortenings were rich in C50, C52and C54 glycerides. Creaming power after 12 min of beating ranged from 1·55 to 1·77 cm3 g−1. Palm stearin‐cottonseed (3:2) oil shortening showed the best creaming performance. The specific volume of cakes ranged, for the experimental shortening, from 90% to 101% from the control, with low erucic acid‐palm blends showing the best performance. In applications for both aerated cream and cakes, inter‐esterified palm olein was excellent.
Immunological investigation of lipases in germinating oilseed rape, Brassica napus
Authors: Murphy Denis J , Cummins Ian , Kang Angray S
Published: October 2006

An anti‐lipase antibody has been used to investigate the lipases of cotyledons from germinating seedlings of oilseed rape, Brassica napusL, var Mikado. Immunological and enzymic assays revealed that lipases were confined to germinating seeds and were absent from other tissues, such as developing seeds, leaves, roots and flowers. The antibody totally inhibited microsomal lipase activity at a ratio of 12 μg IgG protein: 10 μg microsomal protein. It was shown by immunoblotting of microsomal, oil‐body and total cotyledon proteins separated by gel electrophoresis that, in each case, the antibody specifically bound to a single polypeptide. This polypeptide had an electrophoretic mobility consistent with a molecular weight of 56 kDa. The appearance and subsequent decline of the 56 kDa polypeptide during the first 10 days of germination closely followed that of the lipase activity, both in microsomal protein and total cotyledon protein fractions. An ELISA for the lipase demonstrated that the amount of immunoreactive microsomal lipase present at each stage of germination was proportional to its enzymic activity. The enzymic and immunological activities of the microsomal lipase each exhibited buoyant densities of 1.087 g ml−1 on sucrose density gradients. Lipases were present in only very small amounts in dry seeds and were synthesised de novo after 2–3 days of germination.
Use of preference mapping to relate consumer preference to the sensory properties of a processed meat product (tinned cat food)
Authors: Jones Peter N , Macfie Halliday J H , Beilken Shane L
Published: October 2006

The technique of generalised Procrustes analysis was applied to laboratory panel assessments of appearance, texture and aroma properties of ten commercial variants of tinned cat food. These assessments were made using free‐choice profiling and were compared with results obtained from a subsequent fixed‐choice profiling experiment. A consumer trial was also performed in a local supermarket to collect preference scores for the cat food, and these scores were related to the laboratory assessments using preference mapping. These techniques can be used by product developers to ascertain the properties of meat products that are important in determining consumer preference.
Characteristics of mince from pond‐bred silvercarp (Hypophthalmichthys molitrix) and preliminary experiments on its use in sausages
Authors: Gelman Alexander , Benjamin Eugenia
Published: October 2006

The quality of fresh, chilled and frozen mince made from the flesh of pond‐bred silvercarp (Hypophthalmichthys molitrix (Val)) was evaluated. Flavour panel scores for all minces were acceptable and this quality did not deteriorate during storage for one week in a domestic refrigerator (5–6°C) or for one year at −20°C. The levels of oxidative rancidity (2‐thiobarbituric acid analysis) in the minces were consistent with this maintenance of quality.

Aerobic plate counts at 25°C of fresh mince rose from 7–9 × 104 to 1.1 × 105 after 6 days' storage at 5–6°C. Coliform and psychrotroph counts rose from 1.0 × 101 and 7–8 × 103 to 5–4 × 102 and 1.3 × 104, respectively. The functional and textural properties of pond‐bred silvercarp mince in terms of salt‐soluble protein content, water binding capacity and penetrometer values were measured on fresh, refrigerated and frozen samples. All‐fish sausages and frankfurters developed from pond‐bred silvercarp mince were assessed in laboratory and consumer tests against commercial beef sausages and frankfurters. The fish products competed well and achieved levels of acceptance similar to those of the beef‐containing products. Texture measurements revealed slight changes in the fish products during storage for 7 days at 5–6°C. No spoilage was detected in any of the products after a week at 5–6°C. The nutritional advantages of the fish sausages and frankfurters are discussed.
In‐vitro determination of nitrogen digestibility and lysine availability in meat and bone meals and comparison with in‐vivo ileal digestibility estimates
Authors: Moughan Paul J , Schrama Jan , Skilton Grant A , Smith William C
Published: October 2006

The true ileal digestibility of nitrogen was determined in 20 meat and bone meal samples using 120 growing rats. Correction for endogenous ileal nitrogen excretion was based on feeding a further 15 rats a protein‐free diet. The in‐vivo digestibility estimates were compared with in‐vitro values determined using either a multi‐enzyme digestibility assay (method A), the pronase assay (method B) or a multi‐enzyme digestion, pH‐drop assay (method C). The in‐vivo true digestibilities of lysine for 12 of the meat and bone meal samples were compared with fluoro‐dinitrobenzene (FDNB) available lysine values.

The mean in‐vivo digestibility values ranged from 57.2 to 79.1 % and the mean coefficient of variation between rats within meals was 7.6%. For methods A and B the correlations between in‐vitro and in‐vivo digestibility were low and not significant (P>0.05). There was a significant positive correlation between pH at 10 min from the start of in‐vitro digestion and in‐vivo digestibility (r= +0.75; P <0.001) as was the case for pH at 20 min (r= +0.52; P <0.05). The positive relationship between pH at 10 or 20 min and in‐vivo digestibility was contrary to expectation and may have been caused by the potentially high buffering capacity of meat and bone meal. The in‐vitro methods A, B and C each showed a high degree of precision.

The mean in‐vivo true ileal digestibility of lysine in the meat and bone meals ranged from 64.7 to 86.9 %. There was no significant correlation between in‐vivo lysine digestibility and FDNB available lysine. There appeared to be an interaction between FDNB lysine availability and true ileal lysine digestibility, such that the meals with lower in‐vivo digestibility had availability values higher than the corresponding in‐vivo digestibility values.