bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutritional response of mature rats to kidney bean (Phaseolus vulgaris) lectins
Authors: Grant George , Greer Fiona , McKenzie Norma H. , Pusztai Arpad
Published: October 2006

In a series of 10‐day pair feeding experiments it was found that the nutritional value of diets containing beans was essentially the same for rats aged between 30 and 123 days. Thus net protein utilisation (NPU) values of 25–39 on diets containing Processor bean (35 g protein kg−1) + egg albumin (65g protein kg−1) were obtained. As food intakes were considerably reduced when rats were fed diets containing more than 35g protein kg−1 of Processor bean, the measurement of protein utilisation became increasingly more difficult. The severe disruption of the brush borders of duodenal and jejunal enterocytes, originally observed when bean‐containing diets were fed to young (30‐day‐old) rats was also found with rats up to the age of 120 days on similar diets. Similarly, the development of circulating anti‐lectin antibodies in the animals showed no age dependence within the age limits investigated. It was also shown that oral immunisation did not protect the rats from the effects of toxicity and that the immune response was a result of continuous absorption of lectin throughout the feeding period. Thus the extent and the mechanism of toxicity of Phaseolus vulgaris bean lectins were found not to be dependent on the age or maturity of the animal.
Factors affecting n‐nitrosodimethylamine development in germinated barley
Authors: Haley James , Palmer Godfrey H.
Published: October 2006

Study of germinated (malting) barley showed that there was no direct correlation between hordenine levels and the development of N‐nitrosodimethylamine (NDMA) during kilning. Results also indicated that the repression of NDMA formation by sulphur dioxide was more likely to be linked to a chemical reaction with the nitrosating species and changes in oxygen activity rather than to a simple pH effect. Tyrosinase reduced hordenine levelsin vitro.After nitrosation, the tyrosinase‐hordenine digest produced more NDMA than equivalent digests of inactivated tyrosinase and hordenine. This effect of tyrosinase was enhanced by catechol and reduced by sodium metabisulphite. Preliminary studies indicated that both embryo and endosperm food reserves are utilised for hordenine production by the embryo. Further investigations with excised barley embryos suggested that while L‐tyrosine treatment increased hordenine production, L‐methionine treatment increased the potential of the embryos to form NDMA.
Pork quality from pigs fed on low glucosinate rapeseed meal: Influence of level in the diet, sex and ultimate pH
Authors: Dransfield Eric , Nute Geoffrey R. , Mottram Donald S. , Rowan Timothy G. , Lawrence Tony L. J.
Published: October 2006

The appearance and eating quality of pork M. longissimus lumbrum from gilt and castrate pigs fed on diets containing a low glucosinate/low erucic acid rapeseed meal (cv. Tower) were assessed and compared with pork from pigs fed diets containing soya bean meal. At 90 kg liveweight, higher levels of either protein supplement, and therefore higher levels of dietary protein, gave slightly leaner meat. Meat from pigs fed rapeseed meal had more haem pigment and was slightly darker and redder than that from soya bean fed pigs. Differences in the quality of pork from the low glucosinate rapeseed meal and soya bean diets were small. Ratings for texture, juiciness and flavour of the lean varied little between the treatment groups. Suggestions that rapeseed meal as a protein supplement in diets might lead to inferior quality meat were not substantiated. The ultimate pH varied from 5.3 to 7.1 independently of the treatments and provided, for the first time, definitive relationships between pH and eating quality. Toughness and flavour were maximum and juiciness was a minimum after roasting meat of about pH 5.9. The ultimate pH had a larger effect on organoleptic quality than either sex or level of dietary inclusion of rapeseed or soya bean meals.
Carbohydrate components of mongolian apricot fruit (Armeniaca sibirica l.). fractional extraction and general characteristics
Authors: Odonmažig P. , Ebringerová Anna , Badga D. , Janeček František
Published: October 2006

A procedure for the fractionation of ripe Mongolian apricot fruit (Armeniaca sibirica L.) is described. A water‐soluble fraction (31.7% of the dry apricot), obtained from the defatted fruit, contained most of the free sugars, with sorbitol and glucose as the principal components. The cell wall material (9.5% of the fresh fruit) was delignified and successively extracted with EDTA, 5% sodium hydroxide and 17.5% sodium hydroxide+3% boric acid. Subsequent ethanol precipitation, acidification and dialysis yielded a pectic‐rich fraction and four hemicellulose fractions. An almost pure water‐insoluble L‐arabino‐(4‐O‐methyl‐D‐glucurono)‐D‐xylan with the molar ratio of xylose, arabinose and uronic acid 10:1.1:0.8 was obtained; it represents the main hemicellulose component of the cell wall material (3.9% of the dry apricot). The remaining α‐cellulose (10.1% of the dry apricot) retains about 16% of xylan, originally present in the holocellulose.
Determination of aflatoxins by enzyme‐linked immunosorbent assay with special reference to aflatoxin M1 in raw milk
Authors: Jackman Roy
Published: October 2006

There is an increasing requirement for the screening of animal feedstuffs, plant products and edible animal tissues for human consumption, for the presence of contamination by aflatoxins. An enzyme‐linked immunosorbent assay is described which may be used to determine aflatoxins in raw milk at 0.1μg litre−1 and in extracted feedstuffs at the level of 5μgkg−1. The method includes a novel conjugation procedure allowing heterologous conjugates to be prepared resulting in increased sensitivity without interference by sample matrix effects. Suitably cross‐reactive antisera were produced using the cyclopentanone ring of the aflatoxin molecule as the principal immunogenic determinant.
Chlorophyll changes in some green leafy vegetables during cooking
Authors: Faboya Olufemi O.
Published: October 2006

Five green leafy vegetables commonly consumed in Nigeria (Talinum triangulare, Corchorus olitorius, Celosia argentea, Amaranthus hybridus and Vernonia amygdalina) were examined for their chlorophyll contents. These varied between 0.038% for Talinum triangulare and 0.137% for Vernonia amygdalina, with chlorophyll‐a constituting between 68 and 75% of the total chlorophyll. By bringing the temperature of the leaves to 100°C, at least 56% of the total chlorophyll was lost, the rate of loss decreasing with the initial total chlorophyll content. When the leaves were blanched by immersion in boiling water, they showed a greater rate of chlorophyll loss. This was reduced when the pH was adjusted to 6.
Measurement of mimosine and its metabolites in biological materials
Authors: Lowry J. Brian , Tangendjaja Budi , Cook N. W.
Published: October 2006

Recent results in both plant biochemistry and animal metabolism emphasise that, in any research on the nutritional applications of Leucaena leucocephala, measurement of mimosine should be accompanied by measurement of the degradation product 3‐hydroxy‐4(1H)‐pyridone. This may reveal wide differences in the toxic load coming from the feed and in the animal metabolic response to it. The authors suggest that where mimosine analysis can only be performed by the traditional colorimetric method, it should be combined with paper chromatography to estimate ratios of mimosine and 3,4‐DHP. However high performance liquid chromatography provides vastly improved methods for simultaneously and precisely analysing both compounds. Published methods are reviewed and a new ion exchange method is described which has been used for the rapid routine analysis of a large number of samples. The chromatographic properties and separation of 2,3‐dihydroxypyridine, a recently discovered metabolite, and of 3‐glucuronyl‐4(1H)pyridone from the above compounds are also reported.
Analysis of the volatile constituents of black chokeberry (Aronia melanocarpa Ell.)
Authors: Hirvi Timo , Honkanen Erkki
Published: October 2006

The volatile constituents of black chokeberry were analysed by gas chromatography and mass spectrometry. Concentrations of the 48 compounds identified were in general below their individual threshold values. The main compounds were benzaldehyde cyanohydrin, hydrocyanic acid and benzaldehyde. Among other benzene derivatives identified in the press juice were benzylalcohol, 2‐phenylethanol, phenylacetaldehyde, salicylaldehyde, acetophenone, 2′‐hydroxyacetophenone, 4′‐methoxyacetophenone, phenol, 2‐methoxyphenol and methyl benzoate.
A rapid method of dietary fibre estimation in wheat products
Authors: Bell Brenda M.
Published: October 2006

The dietary fibre contents of row and cooked wheat products are highly correlated with their total pentose contents. A colorimetric method for rapid estimation of pentosans in while flour has been adapted for use with products of a wide range of dietary fibre contents, by introducing a prehysrolysis with 0.5m sulphuric acid for 0.5h.
The peroxidase enzyme activity of some vegetables and its resistance to heat
Authors: Müftügil Nezih
Published: October 2006

The peroxidase enzyme activities of some fresh vegetables (cabbage, leeks, carrot, spinach, celery, squash, potatoes, onions and green beans) were determined. The peroxidase activities of cabbage and green beans were high. Onions showed very little peroxidase activity. The vegetables were blanched in hot water at 75°G, 85° and 95°C. Peroxidase inactivation was faster at the higher temperature blanch. Blanching of green beans, potatoes and squash at 75°C for 30 min was not sufficient for complete inactivation of peroxidase enzyme. Peroxidase enzyme inactivation was also affected by the type of vegetable and the size of vegetable pieces.
Effect of added cassava root meal, ZnO and their interaction on the production and quality of eggs from laying hens
Authors: Stevenson Mary H.
Published: October 2006

Two hundred and sixteen (108 Hisex Brown; 108 Warren Studler) laying hens were given one of 12 dietary treatments. These were four basic diets with 0, 200, 400 and 600 g added cassava kg−1 and each basic diet was further subdivided and ZnO added to provide 100 and 200 mg Zn kg−1. None of the production traits measured was significantly affected by either added cassava or ZnO but there was a quadratic response in food intake to added cassava. ZnO addition significantly improved egg quality (assessed by Haugh score) but did not affect shell thickness. Haugh score was significantly affected by added cassava, the responses being significant after 2 weeks storage. The interaction between Zn level and cassava level significantly affected egg quality.
The nutritive value of mixtures of white leaf protein and food proteins
Authors: Carlsson Rof , Hanczakowski Piotr
Published: October 2006

White leaf protein products were obtained from Medicago sativa by precipitation with isopropanol and from Chenopodium quinoa by heat fractionation and ultrafiltration/diafiltration. The isopropanol precipitated protein concentrate from Medicago contained less protein and more ash than the heat fractionated preparation from Chenopodium. The biological value of the protein fraction obtained from Medicago, estimated on rats using the Thomas‐Mitchell balance method, was 59. The biological value of the protein preparation from Chenopodium was low (36). The preparations obtained were mixed with soya bean meal, wheat gluten, bone‐meat meal, fish meal, skim milk and whey in a protein ratio 1:1. In every case, except fish meal, the biological value of the mixtures was higher than that of each component separately. This improvement of the nutritive value can not be explained from the amino acid composition; possibly the lysine availability was low. White leaf protein can, with advantage, supplement other food proteins.
Carbohydrate content of potato (Solanum tuberosum L.) tubers treated with Isopropyl‐N (3‐chlorophenyl) carbamate under different storage conditions
Authors: Khurana Daljit S. , Randhawa Kulwant S. , Bajaj Krishan L.
Published: October 2006

Post harvest application of Isopropyl‐N (3‐chlorophenyl) carbamate considerably reduced the degradation of starch when potato tubers were stored in an evaporative cooling chamber. The starch degraded at a faster rate when tubers were kept under refrigerated and room storage conditions.
A sensitive monoclonal‐antibody‐based test for gluten detection: Quantitative immunoassay
Authors: Skerritt John H.
Published: October 2006

An enzyme‐coupled monoclonal antibody has been used to quantify “gliadin‐like immunoreactivity” in a variety of foods. Small discs of nitrocellulose are soaked in food extract or a series of standard gliadin solutions, and incubated with antibody and an enzyme substrate yielding a soluble product. By use of a photometer, standard curves for gliadin may be constructed and the apparent gliadin content of samples calculated. The reproducibility and reliability of the procedure were examined using a variety of common foods and food proteins. The limit of detection for wheat gliadin was approximately 20μg/ml extract; gliadin levels in excess of this value were found in some “gluten‐free bread mixes” and starch sources. The overall time for analysis is 5–6 h, although for large numbers of samples, overnight blocking of non‐specific antibody binding may be used. It is possible that a “library” of enzyme‐linked monoclonal antibodies could be developed as useful tools for specific food analysis.
A sensitive monoclonal‐antibody‐based test for gluten detection: Choice of primary and secondary antibodies
Authors: Skerritt John H. , Diment John A. , Wrigley Colin W.
Published: October 2006

Of a series of monoclonal antibodies prepared to cereal proteins, two antibodies with specificity for low‐mobility, heat‐stable prolamins in wheat and related cereals were investigated as possible probes for a test for gluten in cooked or processed foods. Urea‐based solvents were found to be superior to isopropanol or sodium dodecylsulphate extractants in allowing sensitive detection of trace amounts of prolamins. The antibodies detected bread and durum wheat and rye prolamins most strongly, followed by barley then oats; detection of maize and rice was quite weak. This selectivity is suitable for a test for prolamins toxic to coeliac‐disease patients. Several enzyme‐labelled second antibodies, for detection of monoclonal antibody bound to cereal protein, were found to be unsuitable reagents since an appreciable fraction of the second antibodies bound directly to the cereal proteins. Sensitive, artifact‐free detection of antibody binding could be performed using the peroxidase‐antiperoxidase technique or by direct conjugation of horseradish peroxidase to the monoclonal antibodies.
Effect of bean broth on the nutritive value and digestibility of beans
Authors: Braham J. Edgar , Bressani Ricardo
Published: October 2006

Black, red and white beans were cooked (1:3, water: beans) at 120°C and 16 lb in−2 for 20 min. Chemical analysis of the broth showed that it contained low levels of protein, ether extract, and carbohydrates and high levels of ash and polyphenols. The effect of the addition of bean broth, on the PER and digestibility of beans was studied in rats. PER values and protein digestibility decreased as the amount of bean broth increased in the diet. White beans showed highest values of PER, weight gain and protein digestibility. The latter was lower in the groups supplemented with methionine than in those not supplemented; there was no interaction beween level of methionine and amount of bean broth in the diet on digestibility. The effect of methionine was not related to either metabolic nitrogen in faeces or amount of food consumed. A high proportion of the faeces nitrogen was soluble in NaOH. When rats from the different groups were fed diets containing 18% bean protein and killed at 6 weeks of age they showed no difference in pancreas weight that could be related to the amount of broth in the diet, nor were the levels of trypsin in the pancreas or the amount of PABA excreted upon ingestion of BT‐PABA related to the amount of broth in the diet.
Acidity in upland and hill soils: Cation exchange capacity, pH and lime requirement
Authors: Logan Katherine A. B. , Floate Michael J. S.
Published: October 2006

For 30 acid upland and hill soils, with initial pH from 3.5 to 5.8, and loss on ignition from 14% to 94%, cation exchange capacity varied with pH according to the relationship CEC = m pH+C, where m and C are characteristic of each soil. The slope m depended on loss on ignition (LOI), and is given by: m=Δ CEC/Δ=0.22 LOI+1.92. Because of these relationships, CEC measured at the natural pH of the soil (in 0.025 M MgSO4 solution) is more relevant to field conditions than a conventional measurement at pH7. An improved method for estimating lime requirement (LR) of these soils was developed, based on the relationship found between LR and the difference in CEC (ΔCEC) between that at the natural pH of the soil and that at the target pH of 5.5: LR=1.12 ΔCEC+1.48. Lime requirement can therefore also be estimated from loss on ignition using the earlier relationships, and is given by: LR=(0.25 LOI+2.15) Δ+1.48, where Δ is the difference between the natural pH (in 0.025 M MgSO4) and the target pH. Predictions based on this agreed well with results for a further 10 soils.
The determination of bitter principles in zucchinis
Authors: Hutt Terrence F. , Herrington Mark E.
Published: October 2006

A method using reverse phase thin layer and high performance liquid chromatography was developed to determine the level of the bitter principle occasionally found in zucchini (Cucurbita pepo L.). The system gave excellent separation with recovery rates of about 90% from spiked fruit. The bitter principle was confirmed by C13 NMR and mass spectrometry as cucurbitacin E glycoside which was present in concentrations in the order of 600mg kg−1 in bitter fruits. Bitterness was detected by a taste panel at cucurbitacin E glycoside concentrations of 1 mg kg−1 in aqueous solutions and 2 mg kg−1 in zucchini pulp. The method described should assist the screening for bitterness in commercial and breeding populations of zucchini.
Chlorophylls and degradation products in orthodox and CTC black teas and their influence on shade of colour and sensory quality in relation to thearubigins
Authors: Mahanta Pradip K. , Hazarika Mridul
Published: October 2006

Chlorophylls and concomitant pigments along with catechins were analysed in shoots from various Tocklai released clones with pronounced genetic variation and in the corresponding orthodox black teas. Comparison of these values with tasters' score showed that the shade of colour of an orthodox black tea is influenced mostly by pheophytin and thearubigins. The degradation of chlorophyll into pheophytin and pheophorbide was also studied in orthodox and crush ‐ tear ‐ curl (CTC) teas. The observations indicated that both pheophytin and pheophorbide are always higher in orthodox than in CTC teas made from the same leaf source.
Extraction of polyphenols and hydrolysis of birdproof sorghum starch
Authors: Kock Johan L. F. , Groenewald Estienne G. , Krüger Gert H. J. , Eloff Jacobus N. , Lategan Pieter M.
Published: October 2006

The presence of polyphenols in the testa and pericarp of birdproof sorghum has an inhibitory effect on enzyme activity during hydrolysis of sorghum starch. In this communication the effect of different NaOH concentrations at various temperatures on the extraction of polyphenols from birdproof sorghum is described. It was found that a 0.25 M NaOH solution extracted all the polyphenols within 75 min at 22°C. The enzymic hydrolysis of birdproof sorghum starch (without polyphenols) was also investigated. A recovery of up to 92±0.6% glucose from the available starch was obtained. The change in sugar composition during hydrolysis was monitored by h.p.l.c.
A review of nitrite and chloride chemistry: Interactions and implications for cured meats
Authors: Sebranek Joseph G. , Fox Jay B.
Published: October 2006

Concerns for the health‐related implications of sodium nitrite and sodium chloride in cured meats have lead to reductions in use of both ingredients and there is evidence of chemical interaction between nitrite and chloride in food systems which have implications for cured meats. This review considers the role of chloride in nitrite chemistry and extends this consideration to evaluation of potential changes in cured meat products. Microbiological control depends on nitrite reactivity and a chloride effect has been demonstrated in Clostridium botulinum spore outgrowth and toxin formation. Changes in flavour of cured meats or in development of cured colour are of lesser concern but may take place. More information on specific inhibitory mechanisms by nitrite is needed.
Effect of ethanol treatment on the proteins of Madhuca (Madhuca butyraceae) seed flour
Authors: Shanmugasundaram T. , Venkataraman L. V.
Published: October 2006

Madhuca butyraceae flour was subjected to a two stage ethanol treatment to remove the toxic saponins and the effect of such treatment on the proteins was determined. Ethanol treatment caused minor changes in the amino acide composition and also in the gel filtration and gel electrophoretic patterns. The limiting amino acids in the ethanol treated flour are lysine and sulphur containing amino acids as compared to the provisional amino acid scoring pattern of FAO/WHO.
Fatty acids from Macoma sp. of bivalve mollusc
Authors: Misra Suniti , Ghosh Mrinal K. , Choudhury A. , Dutta Ashis K. , Pal Prasanta K. , Ghosh Amitabha
Published: October 2006

Fatty acids of the total lipids of flesh and hepatopancreas of Macoma sp. have been determined. The level of 20:5w3 (ca 17%), a biologically important fatty acid, was found to be considerably high. Other major component fatty acids were 16:0, 16:1, 18:1 and 22:4w6. High levels of 22:5w6 (8%), 22:5w3 (8%) and 22:6w3 (ca 15%) were found in flesh lipid. Nonsaponifiables were also high (28–30%). Alkyl ether acyl glycerols were found in flesh (1.3%) and hepatopancreas (3.8%).
Effect of processing on the cyanoglucoside content of cassava
Authors: Nambisan Bala , Sundaresan S.
Published: October 2006

The efficiency of different processes in reducing the cyanoglucoside (CNG) content of cassava was studied. Maximum retention of CNG (>80%) was observed in baked, fried and steamed tubers. CNG retention in sun‐dried chips varied from 30–60%, the retention being governed by the chip thickness. In case of cassava boiled in water, smaller chip size and sufficient water was found to be the ideal condition for maximum CNG removal. There was 25–75% CNG retention in this process, depending on the chip size used. The most effective method for CNG removal was by crushing fresh tuber and subsequent sun‐drying, whereby >95% CNG was eliminated. The studies indicated that the mode of processing greatly influenced the CNG content of cassava foods. It was concluded that since CNG can be greatly reduced by suitable processing, it may not be a limiting factor in the utilisation of cassava for food and feed purposes.
The distribution of anthocyanins in grape skin extracts of port wine cultivars as determined by high performance liquid chromatography
Authors: Bakker Johanna , Timberlake Colin F.
Published: October 2006

The distribution of anthocyanins in methanolic skin extracts of 16 grape cultivars used for port wine production and grown at five sites in the Douro Valley in Northern Portugal has been assessed by high performance liquid chromatography. Results are confined to the seven most readily separated and identified anthocyanins and are expressed as percentages of their total (88–99% of the total integrated area). Anthocyanins based on malvidin (Mv) predominated. Of these, Mv 3‐glucoside was the major pigment (33–60%), being exceeded by Mv 3‐p‐coumarylglucoside (2–51%) in only two cultivars; Mv 3‐acetylglucoside (1–15%) was consistently the lowest. Peonidin 3‐glucoside (1–27%) was prominent in four cultivars, but delphinidin 3‐glucoside (1–11%), petunidin 3‐glucoside (2–11%) and cyanidin 3‐glucoside (trace‐6%) were of low proportions throughout. The ratio Mv 3‐acetylglucoside/total Mv glucosides appeared characteristic of cultivar, independent of site, and a useful aid to identification of grape cultivars. The coloured pulp of some cultivars contained peonidin 3‐glucoside as a major component, present in greater proportions than in the skin; the percentage of Mv 3‐p‐coumarylglucoside was lower in pulp than in skin. The identities of six of the seven anthocyanins were confirmed by fast atom bombardment mass spectrometry and the structures of the Mv derivatives were determined by nuclear magnetic resonance. The formation of formyl and acetyl anthocyanin artefacts is described.
Tannin levels in cassava, a comparison of methods of analysis
Authors: Rickard June E.
Published: October 2006

Low levels of tannins (proanthocyanidins) have been detected in dried cassava (Manihot esculenta Crantz) samples using standard methods of analysis based on extraction procedures. A direct vanillin assay method was compared with other direct methods of analysis based on acid hydrolysis and protein precipitation. The specificity of the methods is discussed in relation to the levels of tannins detected and their potential biological activity in freeze dried fresh and dried/processed cassava samples. The results are discussed with respect to the amount of indigestible material present in the samples. The results of these experiments indicate that tannins present in dried/processed cassava products may be a factor limiting their nutritional value.
Biochemical changes during ripening of some sudanese date varieties
Authors: Mustafa Aziza B. , Harper David B. , Johnston Donald E.
Published: October 2006

Changes in the chemical composition of three popular Sudanese varieties of date (Jawa, Bentamoda and Mishrig Wad Laggai) during ripening are described and are related to changes in texture and in the activities of various degradative enzymes in the fruit. Total invertase levels were high throughout maturation of the three varieties. Although the proportion of soluble enzyme increased during ripening solubilisation did not appear to influence the relative amounts of sucrose and reducing sugars in the ripening fruit. Both cellulase and polygalacturonase were absent or at low levels in the green fruit but displayed large increases in activity during ripening. This enhancement was reflected in a reduction in fruit firmness although little change in cellulose or pectin levels was apparent analytically until the final stage of ripening. Despite a considerable rise in pectinesterase activity during ripening no significant trend could be discerned in the degree of esterification of pectin suggesting that the enzyme is of minor importance in softening of these fruit.
Simultaneous determination of 2,4,6‐trichloroanisole, 2,3,4,6‐tetrachloroanisole and pentachloroanisole in foods and packaging materials by high‐resolution gas chromatography‐multiple ion monitoring‐mass spectrometry
Authors: Whitfield Frank B. , Shaw Kevin J. , Nguyen T. H. Ly
Published: October 2006

A method has been developed for the determination of 2,4,6‐trichloroanisole, 2,3,4,6‐tetrachloroanisole and pentachloroanisole in foods and packaging materials. Using combined high‐resolution gas chromatography‐multiple ion monitoring‐mass spectrometry, and with the addition of 3,5‐dimethyl‐2,4,6‐trichloroanisole as an internal standard, a series of calibration curves were prepared covering the concentration range 0.1 to 100 μg kg−1. The detection limit, with quantitation by extrapolation only, was 0.01 μg kg−1. The mean extraction efficiency of the combined distillation‐extraction step was greater than 90% for each of the chloroanisoles analysed. The mean extraction efficiency for the internal standard was 105%. The reproducibility of the results obtained in the gas chromatography‐mass spectrometry step was assessed and the coefficients of variation lay in the range from 2 to 11%.
Cation replacement of potassium in the total shoot of lettuce and its effect on growth during K deficiency
Authors: Burns Ian G. , Hutsby Wendy
Published: October 2006

The growth and inorganic ion composition of K‐sufficient lettuce shoots were measured after withholding K or K and Na from transplanting in sand culture experiments in the glasshouse. Initial reductions in shoot growth occurred shortly after transplanting in both K‐deficient treatments when the K concentrations were still well above that known to limit enzymic activity. These early growth effects coincided with a rapid decline in total ionic strength within the plants caused by the fall in K concentration which could not be compensated for by increases in the uptake of Na, Mg or Ca, even when adequate concentrations of all of these ions were available. Further rapid reductions in growth rate occurred when the concentration of K declined below about 600 mmol kg−1 in both K‐deficient treatments. These results support the hypothesis of a dual mechanism for the effect of K concentration on growth during K deficiency. The primary effect was caused by a rapid decline in ionic concentration shortly after the K became unavailable which severely affected the mechanisms controlling turgor pressure within the plant. The secondary effect was caused by a reduction in enzymic activity and only became important when the K status of the plant was relatively low.
The effects of dry extrusion of rapeseed with other feedstuffs upon its nutritional value and anti‐thyroid activity
Authors: Smithard Ronald R. , Eyre Michael D.
Published: October 2006

The effects of dry extrusion of mixtures of high‐glucosinolate rapeseed (cv. Jet Neuf) with barley, sunflower meal and rapeseed meal and a mixture of low‐glucosinolate rapeseed (Canola) and sunflower meal upon dry matter intake, utilisation of protein, liveweight gain and anti‐thyroid activity in rats, measured in terms of plasma thyroxine and tri‐iodothyronine, were studied in comparison with equivalent milled mixtures. Extrusion of the Jet Neuf mixtures increased dry matter intake, liveweight gain and biological value of the protein but only for the Jet Neuf/barley and Jet Neuf/sunflower mixtures did extrusion reduce the anti‐thyroid activity. Extrusion of the Canola mixture had no effect on the biological value or anti‐thyroid activity; in both respects it was superior to the Jet Neuf mixt–res.
Effect of pectic polysaccharidases of Pseudomonas solanacearum on cellular components of some food plants
Authors: Ofuya Christopher O.
Published: October 2006

The biological effects of pectic polysaccharidases of Pseudomonas solanacearum were tested on the tissues of certain food plants. It was found that both the endo‐polygalacturonase (PG) EC.3.2.1.15 and endo‐pectate lyase (PL) EC.4.2.2.2 caused loss of cohesion of the cells, and leakage of K+ ions. In addition the enzymes were highly toxic to the cells. Endo‐PL in particular caused ca 82.5% death of potato protoplasts within 1 h of incubation. Data on enzyme absorption showed that tomato tissues (a host plant) absorbed the enzymes whereas there was less absorption of the enzymes by tissues obtained from non‐hosts. These results suggest that the enzymes which are synthesised by the bacterium during its parasitic association with certain food plants affect vital physiological processes of the cells.
The rapid determination of chemically reactive lysine in the presence of carbohydrates by a modified trinitrobenzenesulphonic acid procedure
Authors: James N. A. , Ryley Janice
Published: October 2006

The trinitrobenzene sulphonic acid (TNBS) method has been shown by previous workers to give low results for chemically reactive lysine if carbohydrates are present in the sample. The major factor responsible has now been identified as loss of ϵ‐trinitrophenyl (ϵ‐TNP) lysine during the hydrolysis stage, while adsorption of ϵ‐TNP lysine by humins formed from carbohydrates during hydrolysis has been shown to be insignificant. The loss can be minimised by a reduction of the hydrolysis time without affecting the necessary degree of protein hydrolysis. A modified procedure is suggested which is shown to give very similar results to Carpenter's method (incorporating the Booth modification) for pure proteins and to the Silcock method in the presence of carbohydrates. ϵ‐TNP lysine hydrolysed for 90 min or D,L‐lysine taken through the trinitrophenylation procedure followed by hydrolysis for 120 min are the most suitable standards. The procedure can be completed in under 6 h and does not require the use of expensive equipment or hazardous chemicals.
Air classification of flours of three legume species: Effect of starch granule size distribution
Authors: Cloutt Pauline , Walker Ann F. , Pike Derek J.
Published: October 2006

The effect of starch granule size distribution on separation behaviour of whole starchy grain legume flours during air classification was studied, using laboratory‐scale equipment and two varieties each of cowpea (Vigna unguiculata), faba bean (Vicia faba) and pigeonpea (Cajanus cajan). Cut points at a range of classifier settings were calculated from particle‐size analysis of the fines and coarse fractions using a Coulter counter. The whole flours varied considerably in starch granule size distribution between species and varieties. Cowpea, which contained a high proportion of small starch granules, yielded fines with a higher starch content and a greater dry weight yield than the other species studied.
Appropriate sample for determination of protein in sorghum (Sorghum bicolor (L.) Moench) raised in agricultural trials
Authors: Belavady Bhavani , Subramanya Marithammanahalli Narayanappa , Krishna Murthy Khatokar Narayana Rao , Ramachandra Subbabhat , Bagali Annappa Nanjappa , Hosamani Shivraj Amrithappa
Published: October 2006

Sampling of cereal foods from bulk samples for analyses of nutrients is a well‐known procedure, but a satisfactory sampling scheme for such analyses from breeding and agronomic trials has not been defined. However, selection of five plants from each experimental plot is a common procedure among agricultural scientists. The validity of using grains from such a sample for analysis of protein was tested in the present investigation. Values obtained by analysis of pooled samples of five randomly selected ear‐heads or the average values of five such ear‐heads were not significantly different from those obtained by analyses of sampled aliquots from net plot.
Sucrose accumulation and osmotic potentials in sugar beet at increasing levels of potassium nutrition
Authors: Beringer Helmut , Koch Klaus , Lindhauer Meinolf G.
Published: October 2006

In a pot experiment sugar beet Beta vulgaris L. ssp. vulgaris, cv. Kawetina, was grown on alluvial soil (21 mg exchangeable K 100 g−1) containing 0 (K1), 20 (K2), 40 (K3) and 60mg fertiliser K 100 g−1 soil (K4). The plants were sown on 15 March 1983 and harvested on 23 June, 14 July and 30 August 1983. At final harvest root dry weight/plant had reached 269 g in K1 and between 304 and 310 g in K2‐K4. Sucrose values were 15% (K1) and 17.3–17.7% of root fresh weight (K2‐K4) respectively. The osmotic potential of the storage root decreased with increasing K nutrition and time. At final harvest ψ, was between −1.83 (K1) and −2.26 MPa (K4), 75–79% thereof being contributed by sucrose. Sucrose concentrations in press sap increased from 340–400 mM on 23 June to 475 (K1) and 540–570 mM (K2‐K4) at the end of August. In the same period K concentrations declined from 40–100 to 10–35 mM K+. The sucrose, K and Mg concentrations measured in the press sap were lower than those calculated from sucrose, K, Mg and moisture content of the storage root. This indicates that press sap from thawed storage root tissue is not fully representative. Betaine, analysed only at final harvest, significantly increased with increasing K concentrations in the storage root (r=0.83) and a significant linear regression was found between betaine and sucrose accumulation (r=0.57). This is consistent with the role of betaine as a cytosolic osmoticum for sugar beet storage tissue. Other solutes in the cytosol may also contribute to osmoregulation as sucrose accumulates in the vacuoles.
Prediction of moisture and bulk density in milled peat by near infrared reflectance
Authors: Downey Gerard , Byrne Patrick
Published: October 2006

Calibrations have been developed for the prediction of moisture (34–71% w/w) and bulk density (193–402 g litre−1) in milled peat. Predictive accuracy was satisfactory in the case of moisture (residual standard deviation (r.s.d.)=1.1) but less so for bulk density (r.s.d.=15.1); values for precision (pooled standard deviation between duplicates) were 0.7 and 12.1 respectively. Variations in milled peat colour had no effect on the accuracy of either calibration although variation in sample temperature (+6 to +27°C) resulted in an increased residual standard deviation and the appearance of a small mean bias; precision was also affected.
Processing and fermentation of the african locust bean (Parkia filicoidea Welw.) to produce dawadawa
Authors: Ikenebomeh Marcel J. , Kok Robert , Ingram Jordan M.
Published: October 2006

African locust beans (Parkia filicoidea Welw.) were processed and fermented to the traditional West African condiment dawadawa. The beans were transformed to ‘processed substrate’ by boiling and dehulling, and then fermented at 37°C in static fermenter units. The overall mass balance and the mass balances of several bean components (moisture, fat, protein, ash and carbohydrate) were studied. It was found that 1.0 kg of raw beans (6.4% moisture) yielded 1.3 kg of processed substrate (63% moisture) which in turn was converted to 1.2 kg of dawadawa (65% moisture). The loss of bean solids during processing was due to the removal of adhering pulp and testa as well as to solids extraction during boiling and washing. Overall, 57% of the bean dry weight, 85% of the carbohydrate, 48% of the ash, 40% of the protein and 1% of the fat were lost in the conversion of raw beans to dawadawa. The dawadawa had considerably higher fat and protein contents than the raw beans and was a pleasant tasting food whereas the raw beans were inedible. Some microbiological aspects of the fermentation were also investigated. Normally prepared fermentation substrate was compared with both sterilised and radappertised beans in terms of conversion to dawadawa, number of colony forming units present, and the development of pH and titratable acidity. The presence of microorganisms was found to be obligatory for the conversion to proceed. Simultaneous increases in both pH and titratable acidity were observed during the fermentation.
The determination of soya and meat protein in raw and processed meat products by specific peptide analysis. An evaluation
Authors: Agater Irena B. , Briant Kenneth J. , Llewellyn Jeffery W. , Sawyer Ronald , Bailey Francis J. , Hitchcock Christopher H. S.
Published: October 2006

The detection and measurement of characteristic peptides formed on enzymatic hydrolysis of soya protein products, meats and offals is described. Samples were heated at 120°C for 3h prior to digestion with trypsin overnight, and the resultant peptide mixtures passed through an Amicon ultrafiltration membrane. After concentration the ultrafiltrates were analysed by ion exchange chromatography on Aminex A5 resin. Peptides were detected by post‐column reaction with ninhydrin. Characteristic peaks designated SP 2 and MP 1 were seen in chromatograms of digests of soya protein isolate and beef respectively, and these peaks were well resolved in beef and soya protein isolate mixtures. The SP 2 peak was shown to contain peptides derived from soya 11 S globulin. The soya protein and beef contents of a series of mixtures of freeze‐dried, defatted beef and soya protein isolate were determined by measurement of the SP 2 and MP 1 peaks respectively. Soya protein content could be determined within 2% of the true value over the range 30–70% soya protein isolate and beef content could be determined within 5% of the true value in the range 20–100% beef. Analysis of five soya protein isolates, four soya protein concentrates, six soya flours and 13 textured soya products indicated considerable interproduct variation in the yield of SP 2. The MP 1 peak was seen in a range of meats, both cooked and raw. It was also present in digests of offals which contained smooth or striated muscle but not in ‘non‐muscle’ offals. The protein origin of the MP 1 peak was not established but the yield appeared lower in meat products which had been heated during manufacture than in those which had received no such treatment. Analysis of a series of laboratory prepared canned and heated pork and soya protein isolate mixtures enabled the pork content to be determined to within 8% of the true value, 2% soya protein isolate could be detected but not quantified accurately.
The composition of pith from the sago palms Metroxylon sagu and Arenga pinnata
Authors: Wina Elizabeth , Evans Anthony J. , Lowry J. Brian
Published: October 2006

The tropical sago palms are increasingly regarded as having a major role as energy crops, but many aspects of them are little known. In this study samples of pith were obtained from Metroxylon sagu Roxb. in West Java and South Kalimantan, Indonesia, and from Arenga pinnata Merr. in West Java. Starch content of pith samples obtained from commercially harvested logs varied between 18.8 and 38.8% (fresh weight) for M. sagu and 10.5 and 36.7% for A. pinnata. However core samples of pith obtained in West Java from standing palms of M. sagu suitable for commercial use or from palms of similar dimensions and appearance, gave a much wider range of starch values; from 0.3 to 32.9% (fresh weight). Starch content was highly correlated with water content. Free sugars occurred at up to 5% (fresh weight) and in samples of very low dry matter content there was more sugar than starch. Predominant simple sugars were glucose, fructose and sucrose. Maltose was not detected. Crude protein and fat were negligible constituents. In addition samples were analysed for NDF, ADF, cellulose, lignin, ash, calcium, phosphorus, sodium and potassium. Pith residues obtained following starch extraction in village mills were found to contain significant amounts of starch.
The effects of aqueous extraction on the performance of wheat bran in bread
Authors: Wootton Michael , Shams‐Ud‐Din Mohammad
Published: October 2006

Wheat bran was sieved into coarse, medium and fine fractions prior to extraction with tap water. Bran, bran extract and bran residue were analysed for moisture, protein, fat, ash, pentosan and phytic acid. Farinograph measurements and baking tests showed maximum dough resistance and loaf volume of a white flour were both increased by the addition of the residue. Both these parameters were substantially decreased by bran extract and, to a lesser degree, by the bran itself. These findings were common amongst the size fractions although the residue from the coarse bran had the greatest effect on loaf volume and dough properties.
Studies on the nutritional quality of some cucurbit kernel proteins
Authors: Sharma Prehlad B. , Lal Brij M. , Madaan Tilak R. , Chatterjee Sukumar R.
Published: October 2006

The nutritional quality of proteins of four cultivated cucurbit species was measured by nitrogen balance. The biological value of muskmelon, watermelon and pumpkin proteins were 59, 64, and 67 respectively. A value of 70 for bittergourd kernels was calculated from chemical score. Lysine was the first limiting essential amino acid in all the proteins. The leucine:isoleucine and leucine:lysine ratios did not show imbalance.
The influence of two soil nitrogen levels on the utilisation of 15N‐labelled ammonium nitrate by ryegrass
Authors: Stevens R. James , Gracey Harry I. , Laughlin Ronald J. , Logan Hubert J.
Published: October 2006

In a field plot experiment with grass under cutting management, two soil organic nitrogen levels (0.92% and 1.14% in the top 75mm of soil) were created by repeated applications of pig slurry over a period of 8 years. The influence of soil organic nitrogen level on the recovery by ryegrass of ammonium nitrate fertiliser was then studied by reseeding the plots and applying 15N‐labelled fertiliser at four rates (40, 80, 120, 160kg N ha−1). After each of the first four cuts unlabelled ammonium nitrate fertiliser was applied at these same rates. The percentage utilisation of the labelled fertiliser was measured in five harvests over 2 years. At the first cut the percentage utilisation averaged 46.4% and was independent of fertiliser rate and soil organic nitrogen level. The average percentage utilisation values in cuts 2, 3, 4 and 5 were 9.9, 2.4, 0.8 and 0.5 respectively. For the total of all cuts it was only at the 40 kg N ha−1 fertiliser rate that the percentage utilisation was significantly different (P<0.05) between the 0.92% and 1.14% soil organic nitrogen levels, at 49.0% and 61.4% respectively. The soil nitrogen contribution to ryegrass at the first cut was significantly increased (P<0.05) by the high soil organic nitrogen level at the 40 and 160 kg N ha−1 fertiliser rates. Over all fertiliser rates the average soil nitrogen contribution to the first cut was 50.4 and 61.1 kg N ha−1 at the 0.92 and 1.14% soil organic nitrogen levels respectively. From the first cut data, soil organic nitrogen was estimated to have a net mineralisation rate of 2.6% year−1 and a half‐life of 26 years.
Amine‐binding capacities of food proteins in transglutaminase reaction and digestibility of wheat gliadin with ϵ‐attached lysine
Authors: Iwami Kimikazu , Yasumoto Kyoden
Published: October 2006

Several food proteins were examined for their capacity as substrate in transglutaminase reaction by using a fluorescent amine, monodansyl cadaverine, as donor substrate and following the increase in fluorescence of the reaction mixture. Wheat gluten, or one of its component proteins, gliadin, was the best acceptor among the proteins tested. Compared with intact protein, a preparation of wheat gliadin, modified by transglutaminase‐mediated incorporation of [14C]lysine, showed a marked decrease in in‐vitro digestibility. In rat feeding tests, however, the luminal leavings and excreta collected 24 h after administration of gliadin with ϵ‐attached [14C]lysine contained less than one‐tenth of the radioactivity originally administered. The results presented support the previous notion that occurrence of the ϵ‐γ isopeptide linkage in protein does not significantly impair the in‐vivo digestibility of the protein and nutritional availability of isopeptide bound lysine moieties.
Protein and mineral contents of green leafy vegetables consumed by sokoto population
Authors: Bawa Sulaiman F. , Yadav Satya P.
Published: October 2006

Six green leafy vegetables used extensively in food preparations in northern Nigeria were analysed. Crude protein and ash contents varied from 13.1 to 29.2% and 7.0 to 18.6% respectively. ‘Lalo’ (Corchorus Sp.) had the highest content of sodium (0.31%), iron (0.31%) phosphorus (0.48%) and magnesium (0.47%). There was a significant positive correlation between phosphorus and sodium (r=0.97**), phosphorus and iron (0.81*) and calcium (0.81*) contents.