bluuebunny/crossref_metadata_2025 huggingface dataset:
The 1988 shell lecture Plant Nutrition and Human Welfare: The World Scene
Authors: Greenwood D J
Published: October 2006

The proportion of the world's population that cannot get enough food to eat is increasing. Research has led to methods of increasing yields in ‘good’ soils with heavy inputs of fertilisers and other agrochemicals. But millions of people have to rely on food grown with few inputs on soils that are difficult to manage and present severe nutritional problems. There is a pressing need to devise sustainable systems of production that increase yields for these people. The problems that need to be overcome and the opportunities for advance are examined. Innovative agronomic practices are being developed that show promise of success. Quantitative models for soil and plant processes have also been developed and should be applied, to a greater extent than at present, in assessing possible practices in a given area, and in adapting practices to suit conditions. In addition there are a range of new techniques for measuring soil conditions and plant characteristics which should greatly facilitate progress.

New methods of supplying crops with nutrients and water have led to spectacular improvements in the production of many horticultural crops in the Western world. Improvements in quality and the introduction of new products have been especially notable. They have enriched the lives of the consumer and created wealth for the producer.

Pollution of the environment occurs almost everywhere. It has contributed to the economic decline of some of the earliest industrial areas of the world. Methods of overcoming the chemical constraints to plant growth on polluted and disturbed soils have been devised and have played a major part in improving the appearance of some of these former industrial areas and enabling them to attract modern industries and to enjoy new prosperity. Forest decline brought about by atmospheric pollution is becoming very serious in Western Europe and the USA. So far the only practical remedy involves the application of selected nutrients chosen on the basis of site characteristics.
Use of NAA to inhibit sprouting in sweet potatoes (Ipomea batatas)
Authors: Paton Jane E , Scriven Frances M
Published: October 2006

Sweet potatoes (Ipomea batatas L (Lam) cv LO 323) were treated with naphthaleneacetic acid, and during storage at 25°C per cent sprouting and per cent weight loss were measured. Naphthaleneacetic acid was applied either under reduced pressure as a 1 g litre−1 solution containing wetting agent or as a dust of 1, 10 or 100 mg per gram of talc. Application of naphthaleneacetic acid by either method reduced sprouting by more than 50% during a storage period of at least 40 days, with the exception of the 1 mg naphthaleneacetic acid per gram of talc which reduced sprouting by 29%. Treatments that significantly reduced sprouting increased water loss. A mechanism for the control of sprouting is proposed.
The thymol method for glucosinolate determination
Authors: Tholen John T , Shifeng Shen , Truscott Roger J W
Published: October 2006

This paper details experiments aimed at optimising the conditions for the determination of glucosinolates in rapeseed (Brassica napus L) using the colorimetric thymol procedure.

Glucose could not be substituted for sinigrin when preparing a standard curve for glucosinolate determination unless a correction factor was employed. The value of this factor was found to depend on the concentration of sulphuric acid. Although the coloured complexes formed between thymol and either glucose or sinigrin were found to be unstable at 100°C, the sinigrin/ glucose colour ratio remained relatively constant for incubation times from 40 to 60 min. It was found necessary to increase the amount of thymol present to a final value of 0.23% to ensure complete reaction of glucosinolates. The revised method can be employed successfully for the analysis of glucosinolates in both seed and meal.
Inexpensive, rapid screening method for aflatoxins in peanuts and peanut products
Authors: Sylos Celia M , Rodriguez‐Amaya Delia B
Published: October 2006

Surveys of major Brazilian foodstuffs demonstrated that peanuts and peanut products continue to be very susceptible to aflatoxin contamination. To prevent, or at least minimise, the problem the aflatoxins need to be monitored by a rapid and inexpensive screening method. The AOAC Romer method has been used and found highly reliable. However, the clean‐up step utilises anhydrous FeCl3 and basic CuCO3 which are expensive and not readily available in Brazil. Thus, the extraction (with a mixture of 270 ml methanol plus 30ml 40 g litre−1 aqueous KCl) and clean‐up (150 ml 100 g litre−1 aqueous CuSO4) steps of the method of Soares and Rodriguez‐Amaya (1985) were combined with the AOAC minicolumn to provide a rapid, inexpensive screening technique. Fifty‐two sample lots of peanuts and peanut products were screened by this and Romer's method, and the results were in complete agreement: 28 samples were negative, four < 20 μg kg−1, 12 in the range 20–50 μg kg−1, three in the range 50–100 μg kg−1 and 5 >100 μg kg−1. The results also agreed well when the extracts obtained by the two methods were submitted to quantitative TLC.
Non‐destructive determination of the moisture content of individual wheat grains by nuclear magnetic resonance
Authors: Chambers John , McKevitt Nicola J , Scudamore Keith A , Bowman Clive E
Published: October 2006

The non‐destructive determination of the moisture content of wheat samples as small as an individual grain would have a range of uses whether for repeated measurements, as in physiological studies of development, or to allow subsequent analysis for other factors such as pesticide residues. However, no such method has yet been described. A suitable method has now been developed using an ordinary nuclear magnetic resonance (NMR) spectrometer. With a calibration set of 100 grains, the relationship between NMR response and oven moisture content (range 3‐3 to 19‐6%) was described by a full quadratic model with which there was no remaining lack of fit (1‐465 ns), and the repeatability of the model was acceptable (standard estimate of error 0‐9995). The quality of fit of the NMR predicted moisture content to the oven moisture content for three test sets each of 100 grains was also satisfactory (standard deviation of difference 0‐973 to 1‐352). Using two batches of 25 fumigated grains, the method has been used to show that the different amounts of residues of 1, 1, 1‐trichloroethane were not related to moisture content, as had been previously suggested.
Volatile compounds produced in maillard reactions involving cysteine, ribose and phospholipid
Authors: Farmer Linda J , Mottram Donald S , Whitfield Frank B
Published: October 2006

The interaction of phospholipid in the Maillard reaction between cysteine and reducing sugars is of importance in the formation of meat flavour. The major volatile products of the aqueous reaction between cysteine and ribose, in the absence and presence of phospholipid, have been studied by gas chromatography (GC)‐mass spectrometry and GC‐infrared spectroscopy, and the individual odours assessed by sensory evaluation of the GC effluent. Without phospholipid, sulphur‐containing heterocyclic Maillard products predominated, while the inclusion of phospholipid added lipid degradation products as well as certain compounds specific to the interaction of lipid in the Maillard reaction. The phospholipid also has a marked effect on the overall odour of the reaction mixtures and on the nature of the individual aromas detected.
A review of limonin in grapefruit (Citrus paradisi) juice, its relationship to flavour, and efforts to reduce it
Authors: Fellers Paul J
Published: October 2006

Ever since limonin was first discovered in grapefruit (Citrus paradisi Macf) juice in 1965 and found responsible for significantly contributing to bitterness in the juice, a great deal of research has been directed towards understanding its role therein. Information is presented relative to limonin's chemical determination, taste threshold and content in grapefruit juice, and to relevant legislation. Also considered are (1) several factors affecting the limonin content of grapefruit juice (2) the effect of limonin content on sensory flavour in grapefruit juice (3) the interaction between the Brix: acid ratio and limonin content in affecting grapefruit juice flavour and (4) methods for reducing limonin in citrus juices generally. Finally, recommendations for future studies on limonin in grapefruit juice are reviewed.
Effect of forage cell wall phenolic acids and derivatives on rumen microflora
Authors: Hartley Roy D , Akin Danny E
Published: October 2006

The trans isomers of methyl and t‐butyl esters of p‐coumaric acid and 4,4′‐ dihydroxy‐α‐truxillic acid were compared with trans‐p‐coumaric acid in relation to their toxicity against rumen microorganisms. Toxicity was evaluated by the effect on growth of pure cultures of Bacteroides ruminicola and Ruminococcus flavefaciens and by the effect on dry matter loss in in‐vitro digestion studies using rumen fluid. Growth of the pure cultures of rumen bacteria was reduced by the methyl and t‐butyl esters as much as or more than by p‐coumaric acid. In contrast, 4,4′‐dihydroxy‐α‐truxillic acid, a photodimer of p‐coumaric acid, was only marginally inhibitory to growth of these bacteria. At 5 mM concentration in rumen fluid, the esters inhibited dry matter digestion of bermudagrass by rumen bacteria and by fungi, but results for 4,4′‐dihydroxy‐α‐truxillic acid were similar to the control treatment in which no phenolic compound was added.
Cyclodimers of p‐coumaric and ferulic acids in the cell walls of tropical grasses
Authors: Ford Clive W , Hartley Roy D
Published: October 2006

Cell walls from leaves and stems of three tropical grasses (Setaria anceps cv Nandi (Schumach) Moss), pangola grass Digitara decumbens Stent and spear grass Heteropogon contortus (L) Beauv ex Roemer & Schultes were extracted with alkali, and ether‐soluble fractions were prepared from the acidified solutions. Cyclobutane dimers derived from p‐coumaric acid (CA: 3‐(4‐hydroxypheny) propenoic acid) and ferulic acid (FA: 3‐(4‐hydroxy‐3‐methoxyphenyl) propenoic acid) were found in all plant residues. Structural information on the dimers was obtained by gas chromatography‐mass spectrometry. Stem cell walls differed from those of leaf in having major dimer components which contained residues tentatively identified as coniferyl alcohol (3‐(4‐hydroxy‐3‐methoxyphenyl)‐2‐propen‐l‐ol). Species differences in leaf cell wall cyclodimers were evident. Pangola and setaria grasses had dimers mainly derived from FA, whereas spear grass had over 70% of dimers derived from CA. Di‐esterification of some dimers in the cell walls was confirmed by the release of dimers containing the reduced forms of CA and FA (coumaryl and coniferyl alcohols respectively) when leaf cell walls were extracted with borohydride. Head to tail dimerisation giving derivatives of truxillic acid (t‐2, c‐4‐diphenyl‐r‐l, t‐3‐cyclobutanedicarboxylic acid) predominated, although evidence was obtained for the presence of head‐to‐head coumaric acid dimers (derivatives of truxinic acid, t‐3, t‐4‐diphenyl‐rl, c‐2‐cyclobutanedicarboxylic acid) in setaria stem and spear grass leaf. The results suggested that cyclodimers in grass cell walls occurred in cross‐linking structures of varying complexity between macromolecules, where they would possibly contribute to fibre strength and thus have an adverse efect on the nutritional value of forage.
Effect of nutrition variables on solid state alcoholic fermentation of apple pomace by yeasts
Authors: Gupta L K , Pathak G , Tiwari R P
Published: October 2006

The fermentation of apple pomace to ethanol via solid state fermentation has been studied using Saccharomyces cerevisiae, S. diastaticus, Pichia fermentans, Candida utilis and C tropicalis. The effect of nitrogen, phosphate and trace elements has been compared in selected strains (S cerevisiae T2 and S diastaticus) on the basis of the fermentation efficiency of apple pomace. An improvement in fermentation efficiency was observed with both the strains on adding various phosphates, nitrogen sources or trace elements. However, the extent of stimulation in most cases was higher when the test strain was S diastaticus.
Reducing gaseous losses of nitrogen from cattle slurry applied to grassland by the use of additives
Authors: Pain Brian F , Thompson Rodney B , Rees Yvonne J , Skinner Jonathon H
Published: October 2006

Losses of nitrogen (N) through ammonia (NH3) volatilisation and denitrification were determined following the application of cattle slurry to grassland in autumn or spring. Denitrification was examined on two contrasting soils. A system of small wind tunnels was used to measure NH3loss and an acetylene inhibition technique for denitrification. Between 31 and 84% of the ammonium N (NH‐N) applied in slurry was lost through NH3volatilisation. Acidifying the slurry to pH c 5.5 prior to application reduced these losses to between 14 and 57%. On a freely drained loam soil, denitrification from unacidified slurry applied in the autumn at 80 m3ha−1was continuous throughout the winter, with the maximum rate of 0.91 kg N ha−1day−1occurring a few weeks after slurry application. The total denitrification losses were equivalent to about 29% of the NH‐N applied for this treatment and 41% for the acidified slurry. The nitrification inhibitor dicyandiamide reduced the amount of N lost through denitrification by 70% when applied with the slurry at 25 kg ha−1, by 55% at 20 kg ha−1and by 30% at 15 kg ha−1. The nitrification inhibitor nitrapyrin did not appreciably reduce denitrification. Denitrification losses were consistently small from slurry applied to the freely drained loam soil in spring, or to a poorly drained, silty clay in autumn or spring. Neither nitrification inhibitor was of benefit in these situations.
Metabolism of small peptides in rumen fluid. Accumulation of intermediates during hydrolysis of alanine oligomers, and comparison of peptidolytic activities of bacteria and protozoa
Authors: Wallace R John , McKain Nest , Newbold C James
Published: October 2006

Oligopeptides of L‐alanine up to ala5, were incubated in vitro in either strained rumen fluid or suspensions of mixed rumen bacteria. The disappearance of substrates and formation of products were measured for 40 min, by which time ala3, ala4 and ala5 were almost totally hydrolysed. Ala2 was more slowly hydrolysed, and accumulated in incubations with the other peptides. The pattern of formation of ala2 but not ala3 from ala4, and ala3 and ala2 but not ala4 from ala5, suggested that the peptides were being hydrolysed by a dipeptidyl peptidase mechanism. Three different sheep receiving different diets gave similar results. Neither substrates nor products appeared to be accumulated intracellularly, except for ala2, and then only if protozoa were present. Protozoa were more active than bacteria in ala2 hydrolysis, whereas bacteria had greater activities with higher homologues. Similar preferences were observed with glycine peptides, although unlike alanine peptides gly3 and gly5 were more slowly degraded than the dimer. These experiments suggest that protozoa are of importance in the accumulation and hydrolysis of dipeptides, whereas bacteria are responsible for the breakdown of larger molecules by a dipeptidyl peptidase mechanism that does not appear to involve accumulation within the cell.
Detection and quantification of adulteration of durum wheat flour by flour from common wheat using reverse phase HPLC
Authors: McCarthy P Kieran , Scanlon Bernard F , Lumley Ian D , Griffin Martin
Published: October 2006

When common wheat (Triticum aestivum L) gliadins were separated by RP‐HPLC, a major doublet peak eluted at 47.20 and 47.94 min. This peak was consistently found to be absent in Durum wheat (Triticum durum Desf) gliadins separated under identical conditions. In Durum wheat gliadins a characteristic small peak eluted at 48.30 min followed at 50.47, 510.37, 52.80 min by larger peaks. The peak area ratio of the peaks eluting at 50.47 and 51.37 min was found to be 2.18 (±0.14). This ratio was found to decrease proportionally on contamination of Durum wheat flour with flour from some common wheat varieties. This ratio alone was not enough to detect and quantify adulteration by all varieties of common wheat. An alternative method was found whereby the peak emerging between 47 and 49 min in the Durum wheat gliadin elution profile was expressed as a ratio of the total protein applied. This ratio was shown to increase when Durum wheat flour was adulterated with flour from common wheat thus enabling quantitative estimation of the level of adulteration. A third method of detecting adulteration of Durum wheat flour is also proposed in which the peak emerging between 47 and 49 min is collected and the protein separated by PAGE. The presence of more than one band of γ/β‐gliadins is indicative of adulteration.
Protein quality of parched immature durum wheat (Frekeh)
Authors: Takruri Hamed R , Humeid Muhammad A , Umari Muhammad A H
Published: October 2006

The protein quality of parched immature Durum wheat (frekeh) produced from Deir Alla‐2 variety was evaluated. Frekeh from two maturity stages was used: one at the end of the milk stage (F1) and the other at the end of the dough stage (F6). Two animal experiments were carried out in which net protein utilisation (NPU) was determined for the two samples and for mature wheat using Sprague Dawley rats, the first for 12 and the second for 11 days. Additionally, the chemical scores for these cereals were calculated.

The results indicated that the protein of F1 was of higher quality than that of F6 or mature wheat; the protein efficiency ratio adjusted values for F1, F6 and wheat were respectively 2.70, 1.93 and 1.45, and the NPUop values were 53, 46 and 44 respectively. There was agreement between these results and the chemical score values as they were 54, 41 and 42 for F1, F6 and wheat respectively. There was a significantly higher voluntary intake of cereal‐based diets in comparison with the casein‐based diet (P <0.05).

Thus it is shown that frekeh produced from wheat harvested at an early stage of maturity was of higher protein quality than that produced at a late stage of maturity or mature wheat.
Hydrolysis of grape monoterpenyl glycosides by Candida molischiana and Candida wickerhamii β‐glucosidases
Authors: Gunata Y Z , Bayonove C L , Cordonnier R E , Arnaud A , Galzy P
Published: October 2006

The exocellular β‐glucosidases of Candida molischiana and Candida wickerhamii are able to hydrolyse geranyl, neryl, citronellyl, linalyl and α‐terpinyl‐β‐D‐glucopyranosides. The nature of the aglycone residue greatly affects the rate of hydrolysis. Glucosides with a tertiary alcohol as aglycone residue are more slowly hydrolysed than those with a primary alcohol. The β‐glucosidase from C molischiana is also able to hydrolse α‐L‐arabinofuranosides. This results in the release of monoterpenols from a glycoside extract from grape juice.
Effects of postharvest treatment on the sensory qualities of kiwifruit harvested at different maturities
Authors: MacRae Elspeth A , Stec Margaret G H , Triggs Chris M
Published: October 2006

The effects of various postharvest treatments on the sensory qualities of eating‐ripe kiwifruit (Actinidia deliciosa var deliciosa (A Chev) Liang et Ferguson cv Hayward) were compared. When fruit from early harvests (5.3, 6.4% w/v soluble solids (SS) at harvest) were treated with ethylene immediately after harvest, eating‐ripe fruit were more juicy and generally had fewer off‐odours than fruit not ripened by ethylene.

A short period (4‐6 weeks) of storage at 0° C was beneficial to fruit quality, particularly when applied to fruit from early harvests. Flavour intensity was enhanced, and off‐flavours, greenness and acidity were decreased.

There was variation in fruit quality between orchards. The poorest quality fruit were those from one orchard after storage at 4° C for 4 weeks or at 0° C for 12 weeks prior to ripening. The fruit stored at 4° C was notable for its lack of sweetness and high incidence of earthy off‐flavours. Fruit from both these treatments also had a higher incidence of caramel/burnt sugar flavours than fruit from other treatments.

There was no relationship between perceived sweetness and fruit sugar content, SS or sugar/acid ratios, and only a minimal relationship between perceived acidity/tang/sourness and concentrations of each acid. Some suggestions are offered to explain these findings.
Lipid levels in cabbage leaves (Brassica oleracea)
Authors: Komaitis M E , Melissari‐Panagiotou E
Published: October 2006

Cabbage (Brassica oleracea L, var Glory) is one of the cruciferous vegetables. The objective of this study was to investigate the neutral, glyco‐ and phospholipids of cabbage and their fatty acid composition. Lipids from its leaves were extracted and fractionated into neutral lipids, glycolipids and phospholipids. The fatty acids of each fraction were analysed by gas liquid chromatography.
Analysis of carbohydrates in seven edible fruits of Bangladesh
Authors: Nahar Nilufar , Rahman Shakila , Mosihuzzaman M
Published: October 2006

Dry matter, ash, lignin, starch and soluble and insoluble dietary fibre contents of the edible parts of seven fruits of Bangladesh were determined. Analysis of the low molecular weight carbohydrates showed that all the fiuits, except lukluki and hogplum, contained substantial amounts of these materials of which glucose and fiuctose were the main components. The main constituent of the polysaccharides in all the fruits was glucose. The dietary fibre contents of the dry fruits ranged from 29% to 79%. Lukluki has by far the best combination of low fiee sugars and high dietary fibre, and pineapple the worst.
Prediction of sensory quality by near infrared reflectance analysis of frozen and freeze dried green peas (Pisum sativum)
Authors: Kjølstad Lise , Isaksson Tomas , Rosenfeld Hans J
Published: October 2006

Frozen, green peas (Pisum sativum L ) of different varieties and different levels of maturity were evaluated by sensory analysis using a panel of ten trained judges. Two texture variables (hardness and mealiness) and four flavour variables (pea flavour, sweetness, fruity flavour, off flavour) were considered. Near infiared reflectance ( N I R ) analysis was performed with the same material, on both the fiozen and fieeze dried peas. The N I R instrument was calibrated to predict the sensory variables using the multivariate analytical method of principal component regression. Tenderometer readings of the same peas were also calibrated to predict the sensory variables. N I R analysis on the fieeze dried peas showed relative ability of prediction (RAP) values for the sensory variables which were higher than those for the tenderometer readings. The sensory attributes pea flavour and hardness were predicted with higher RAP values by tenderometer readings than by N I R analysis on fiozen peas.

For the rest of the attributes, N I R analysis on fiozen peas gave higher RAP values than tenderometer readings. N I R generally gave high RAP values, and this tentative study suggests that N I R analysis could be a useful tool in instrumentally assessing the quality of frozen peas.
Quantitative determination of suberin deposition during wound healing in potatoes (Solanum tuberosum L)
Authors: Sukumaran Narakkat P , Jassal Jagdish S , Verma Sirish C
Published: October 2006

Quantitative determination of suberin deposition during wound healing of potatoes (Solanum tuberosum L ) has shown that at RH> 90 % a maximum amount of suberin was deposited at 25°C. A significantly greater amount of suberin was deposited at the basal region of the tuber as compared with the apical and middle regions.
Effect of calcium on the storage life of oro (Antiaris africana)
Authors: Lasekan Olusegun O
Published: October 2006

The effects of calcium on the ascorbic acid, chlorophyll, titratable acidity and texture (firmness) of stored oro (Antiaris africana (Mill)) friuits (average weight 100 g ) were studied. Three groups of the fruits were dipped in 20 g litre−1, 40 g litre−1 CaCl2 solutions and deionised water respectively for I0 min. The fourth group, which was untreated, served as the control and was also packaged in heat‐sealed cellophane bags. The fruits were displaced and stored at ambient temperature (28 ± 2°C). The calciumtreated fruits which kept better were firmer and had a slight colour change (chlorophyll) which also produced a progressive increase in ascorbic acid level during storage. The titratable acidity of the fruits did not fluctuate as signijcantly as that of the untreated (control) fruits.
Variability in the saccharide, protein, phenolic acid and saponin contents of four market classes of edible dry beans
Authors: Drumm Terri D , Gray J Ian , Hosfield George L
Published: October 2006

The content and composition of the saccharides, protein and amino acids, phenolic acids, and saponins of four market classes (navy, dark red kidney, pinto and Black Turtle Soup) of edible dry beans (Phaseolus vulgaris L) were determined. These compounds are potential precursors of flavour development in the processed beans and may contribute to the unique flavour characteristics of the various bean classes.

The contents of sucrose and stachyose were significantly different (P < 0.05) for the four bean classes and ranged from 2.63 to 4.80 g per 100 g and 2–81 to 4–21 g per 100 g, respectively. Total nitrogen contents ranged from 3–92 to 4–71 g N per 100 g and were significantly different. The distribution of the amino acids was similar for the four bean classes. Coumaric, ferulic, sinapic and cinnamic acids were identified. The phenolic acid soluble esters were the predominant fraction, with lesser amounts of the free and insoluble phenolic acids. The total saponin contents of the bean classes were similar. Significant (P <0–05) differences in the distribution between the three major saponin components were observed.
Effect of sulphur dioxide on microbial growth in refrigerated pre‐peeled potatoes packaged in plastic films
Authors: Giannuzzi Leda , Zaritzky Noemi
Published: October 2006

Microbial growth in pre‐peeled potatoes was analysed to determine the simultaneous effect of sodium bisulphite concentration (105–219 mg kg−1), storage temperature (4, 7 and 10°C) and gaseous permeability of the packaging plastic film (polyethylene and EVA—SARAN—EVA used in vacuum) on product storage life.

Composition of the microbial flora was determined at the beginning and the end of the storage period, and the principal microorganisms causing spoilage of the product were observed to be Pseudomonas spp and Enterobacteriaceae. Lag phase duration and specific rate constants were determined for these microorganisms in samples stored at each condition.

In polyethylene‐packaged samples microbial growth was observed at various temperatures and SO2 concentrations were tested. With vacuum packaging in low oxygen permeability films and residues of 100 mg SO2 kg−1, microbial counts were maintained in the lag phase; larger residues produced microbial inhibition at 4, 7 and 10°C.
Preparation of detoxified high functional rapeseed flours
Authors: Schwenke Klaus Dieter , Kroll Jürgen , Lange Reinhard , Kujawa Manfred , Schnaak Werner , Steinert Albert
Published: October 2006

Functional rapeseed flours were prepared by a mild soaking process using citric acid or ammonium carbamate. This treatment was effective in lowering the content of sinapine, glucosinolates and their hydrolysis products. A post‐treatment with alcohol/ammonia/water removed vinyloxazolidinethione, nitrites and isothiocyanates totally and left traces only of the glucosinolates. The treated flours possessed increased water and oil absorptions and excellent foaming properties. The soaking process also resulted in decrease of cooking loss in model meat systems of the Frankfurter type. The treatment did not change the amino acid composition which gave an essential amino acid index of 86–89.
The problem of refolding and reassembling recombinant vicilin subunits
Authors: Chambers Stephen J , Carr Helen J , Plumb Geoffrey W , Lambert Nigel
Published: October 2006

The reassociation of a storage protein (pea (Pisum sativum L) vicilin) expressed in yeast (Saccharomyces cerevisiae MC16 (ade 2–1, leu 2–3, lys 2–1, his 4–712FS, SUF 2)) was investigated. The corresponding protein in French, bean (Phaseolus vulgaris L), termed phaseolin, was used as a model to produce a methodology for the refolding of the recombinant protein. Phaseolin was successfully renatured from its dissociated state in 5 M guanidinium chloride. Application of this rationale to yeast‐derived vicilin proved unsuccessful. The nature of the yeast vicilin and its failure to refold and reassemble correctly are discussed together with the further experimental approaches required.
Individual variation in the amino acid and chemical composition of defatted cocoa bean meal of three varieties of cocoa (Theobroma cacao) from south‐eastern Nigeria
Authors: Offem John O
Published: October 2006

Cocoa in the world market is the ripened bean of the cocoa tree (Theobroma cacao L) that has been properly fermented and dried. A number of varieties are found such as Amelonado and F3Amazon which are considered ‘bulk’ cocoas by the FAO. Chocolate produced by these cocoas does not, possess the additional flavours associated with the ‘finey’ types such as Trinitario and Criollo. Literature exists on the composition of cocoa bean meal but the work reported has been on bulk samples received by chocolate manufacturers or found in warehouses. These are beans harvested from several trees and of varied and unknown species growing in different localities. Therefore differences due to environmental and varietal factors will be masked. This work, which was carried out on cocoas from south‐eastern Nigeria, is aimed at highlighting the variation in composition (if any)of the cocoa bean between (a)individual species, (b) individual trees of each species planted at the same time and in the same geographical area, (c) individual trees of the same species, planted in the same area but having an age difference of some ten years.
Endogenous flow of total lysine and other amino acids at the distal ileurn of the protein‐or peptide‐fed rat: The chemical labelling of gelatin protein by transformation of lysine to homoarginine
Authors: Moughan Paul J , Rutherfurd Shane M
Published: October 2006

Endogenous total lysine flow at the distal ileum was determined directly with seven 200‐g male rats fed a gelatin‐based diet in which all the lysine had been transformed to homoarginine. The latter lysine flow was compared with one determined indirectly with seven rats given a partially guamdinated gelatin‐based diet. There was no significant difference (P > 0.05) between the direct (469 ± 27.9 μg g−l freeze dry matter intake (FDMI);x̄ ± SE) and indirect (506 ± 44.2 μg g−1 FDMI) estimates. The overall mean endogenous lysine flow for the 14 rats receiving the guamdinated gelatin‐based diets was compared with flows determined with six rats given a diet the sole nitrogen source of which was enzyme hydrolysed casein (EHC) and six rats fed a protein‐free diet. The EHC, a mixture of free amino acids and oligopeptides, was assumed to be completely digested and absorbed by the end of the small intestine of the rat. The mean flow of lysine for the EHC‐fed rats(522 ± 24.8 μg g−l FDMI) was not significantly different (P > 0.05) from that for the rats given the guanidinated gelatin‐based diets, but the flow for those on the protein‐free diet was significantly lower (238 ± 9.4 μg g−l FDMI). The endogenous flows of the amino acids other than lysine for the EHC‐fed rats, were higher (P < 0.05) than values found for rats on the protein‐free diet, except for glycine where there was no significant difference. It was concluded that there is a direct effect of dietary protein and peptides on the net loss of endogenous lysine and other amino acids from the small intestine of the growing rat. Endogenous amino acid flow at the terminal ileum may be underestimated when measurement is made using the traditional protein‐free method.
Effect of gamma irradiation parameters on the in‐vitro digestibility of β‐lactoglobulin
Authors: Voisine Richard , Parent Guy , Savoie Laurent
Published: October 2006

Radiation level and protein conformation during irradiation may modify a protein's response to ionising energy and change its nutritional value. Effects of gamma irradiation on protein in‐vitro digestibility and amino acid release were investigated using β‐lactoglobulin as a model protein. Irradiation with 60Co was performed at a range of 1–50 kGy on liquid or frozen samples atAw 0.93, with pH adjusted to 5.2 or 7.0, and on dry samples atAw 0.13. Amino acid composition, in‐vitro protein digestibility and amino acid release were not impaired by irradiation at the highest dose of 50 kGy. Thus the nutritional quality of β‐lactoglobulin was not affected by irradiation in a dose range likely to be used in food processing.
A new method for manufacture of lactose‐hydrolysed fermented milk
Authors: Toba Takahiro , Hayasaka Ibuki , Taguchi Shigekatsu , Adachi Susumu
Published: October 2006

Lactose‐hydrolysed fermented milk was manufactured by sonication in the course of fermentation. The milk was inoculated with Lactobacillus delbrueckii subsp bulgaricus or L helveticus, incubated for 4 h, sonicated, and incubated for an additional 12 h. The sonication resulted in 71–74% depletion of the initial lactose whereas 39–51% lactose hydrolysis was obtained in non‐sonicated milk.
Silver ion chromatography of triacylglycerols on solid phase extraction columns packed with a bonded sulphonic acid phase
Authors: Christie William W
Published: October 2006

Solid phase extraction columns packed with a stationary phase with bonded benzene sulphonate groups can be converted to the silver ion form and utilised for the separation of molecular species of triacylglycerols. Stepwise elution with dichloromethane/methyl acetate mixtures gave pure trisaturated‐ and disaturated‐monoene species, together with a mixed fraction containing saturated‐dimonoene and disaturated‐diene; the remaining more highly unsaturated species were recovered by elution with a solvent containing a high proportion of acetonitrile. Fractions were identified and quantified by gas chromatography after transmethylation in the presence of an internal standard. This permitted calculation of the relative proportions of the two species in the third fraction. The procedure was applied to cocoa butter, palm oil and sheep subcutaneous adipose tissue.
Effects of proteolysis on the sensory properties of the sweet protein, thaumatin
Authors: Shamil Syed , Cusack Maggie , Beynon Robert J
Published: October 2006

We have examined the effects of different proteases on the sensory properties of the sweet protein, thaumatin. Trypsin and thermolysin, proteases with quite different primary specificities, have little effect upon the sweetness of ihaumatin, although in each instance the protein has been extensively cleaved. The retention of the sweet taste is probably due to the disulphide bridge cross‐linking which serves to maintain the overall structure of the molecule even when it has incurred proteolytic cleavages. By contrast, subtilisin and chymotrypsin effect greater digestion, to the extent that the protein is reduced to small peptides even when the disulphide bridges are intact. Under these circumstances the sweet taste is lost. The sensory properties of thaumatin depend upon the maintenance of a part of the polypeptide chain in a particular conformation.
Non‐starch polysaccharides of canola meal: Quantification, digestibility in poultry and potential benefit of dietary enzyme supplementation
Authors: Slominski Bogdan A , Campbell Lloyd D
Published: October 2006

The non‐starch polysaccharide (NSP) content as determined by gas chromatography (component neutral sugars) and colorimetry (uronic acids) was shown to be 16–22% in ten different samples of defatted canola (low glucosinolate rapeseed) seed. The non‐cellulosic components of NSP accounted for 13–16% of the meal and on average consisted of arabinose (33%), xylose (13%), galactose (13%), glucose (5%), mannose (3%), rhamnose (2%), fucose (2%) and uronic acids (30%). Yellow‐seeded and brown‐seeded samples of canola contained similar contents of total dietary fibre although the composition of the fibre components tended to differ with the former showing a low content of lignin and associated polyphenols and a high content of NSP as compared with the latter type. NDF values tended to be lower for yellow‐seeded than for brown‐seeded canola due to the relatively high content of NSP in neutral detergent solubles of yellow‐seeded canola. An initial balance study with laying hens showed low (<3%) digestibility of the polysaccharide components, and further studies were conducted with a commercial enzyme preparation (SP249, Novo Laboratories Ltd, Lachine, Quebec) to enhance the in‐vivo hydrolysis of the NSP fraction of the meal. Laying hens were fed a semipurified diet containing 40% commercial canola meal with and without enzyme (1%). NSP digestibility was increased to 37% by the enzyme supplementation.
Dietary zinc and the zinc components in various foods subjected to in‐vitro enzymic digestion
Authors: Ikeda Sayoko
Published: October 2006

Several foods consisting of animal and plant foodstuffs as dietary sources of zinc were subjected to peptic and pancreatic digestion. The soluble zinc components in their digesta were separated by gel filtration chromatography on Sephadex G‐50 with 0.1 M Tris‐HCl buffer (pH 8.0). The soluble zinc released on the enzymic digestion of the foods ranged from 41 to 98% with an average of 65%. Chromatographic analysis indicated that most of the soluble zinc consisted of between one and four components with molecular weights of around 10 000 or less, except for a component from egg yolk of higher molecular weight.
Effect of cultivar and harvest date on dry‐matter content, hardness and sugar content of swedes for stockfeeding
Authors: Gemmell Dorothy J , Griffiths D Wynne , Bradshaw John E
Published: October 2006

Eighteen bulbs of each of four cultivars and two inbred lines of swede (Brassica napus ssp rapifera L) were harvested at monthly intervals from 25 July 1988 to 6 March 1989. On average, dry‐matter yield increased from 50.8 to 277.0 g plant−1 by 14 November and then slowly fell to 240.5 g plant−1 on 6 March; and dry‐matter content rose from 99.5 to 118.9 g kg−1 fresh weight on 19 September and then slowly declined to 99.0 g kg−1 fresh weight in March. Hardness also increased from 25 July to 19 September but then remained constant. A hard high‐dry‐matter line, BWc4hca, and a soft lowdry‐matter line, CRdagaa, were the extremes for changes in sugar content. From July to October the average contents in g kg−1 DM of BWc4hca and CRdagaa were respectively: fructose 146.8, 224.3; glucose 206.8, 293.7; and total 390.7, 543.9. In contrast, from November to March their contents were much closer: fructose 187.9, 209.9; glucose 314.7, 323.I; and total 534.4, 549.3. Sucrose levels were much lower and more variable, but overall BWc4hca was highest, 34.1, and CRdagaa lowest, 20.6. The implications for swede breeding are discussed.
Monitoring hydrogenation in the margarine industry by low resolution pulsed NMR
Authors: Khaloui Mohammed El , Rutledge Douglas N , Ducauze Christian J
Published: October 2006

An N M R method has been developed to monitor the hydrogenation of various oils used as raw materials in the margarine industry. The method is based on the determination of a monoexponential approximation of the longitudinal relaxation time, T1, which is shown to be highly correlated with the iodine number.
Comparison of different digesta collection methods to determine the apparent digestibilities of the nutrients at the terminal ileum in pigs
Authors: Köhler Torsten , Huisman Joop , Den Hartog Leo A , Mosenthin Rainer
Published: October 2006

Three different cannulation techniques in pigs were tested with 15 crossbred castrates. Four pigs were fitted with a simple T‐cannula, six pigs with a postvalve T‐caecum cannula (PVTC cannula) and five pigs with ileocaecal reentrant cannulas. Four diets were tested: a conventional diet, a pectin‐rich diet, a crude fibre‐rich diet and a semisynthetic diet. For quantitative collection of ileal digesta the PVTC cannulation technique was tested for homogeneity of sampling. Cr2O3 and TiO2 were used as solid phase markers and Co‐EDTA as a liquid phase marker. The digestibilities of dry matter, nitrogen, crude fibre, ADF and NDF were determined. Digestibilities measured with re‐entrant cannula as a quantitative collection method were sometimes significantly higher (P < 0.05) than with the other cannulas. After correction to 100 % Cr recovery the differences were reduced to less than 5%. Nitrogen digestibility measured with the re‐entrant cannula was lower than with the PVTC cannula in the fibre‐rich and semisynthetic diets. The Crrecovery was mostly lower than 100%, except with PVTC cannulas and the semisynthetic diet. The recovery rates of Co were higher than those of Cr. In the semisynthetic diet, recoveries of Co and Cr were similar. The recovery rate of TiO2 with the semisynthetic diet was lower than that of the other two markers. The recovery rates of the markers depended on fibre contents of diets. With the pectin‐rich and fibre‐rich diets the Cr and Co recoveries were lower than with the control diet. In general, digestibility coefficients measured with the three different cannulation techniques were different. However, when corrections were made for marker recoveries there were only small differences.
Chemical Evaluation of Musa ‘Bhimkol’ as a Baby Food
Authors: Barthakur Nayana N , Arnold Neville P
Published: October 2006

The edible pulp of Musa ‘Bhimkol’ was analysed for certain organic compounds and mineral nutrients at two stages of development of the fruit to evaluate it as a baby food. Energy value and carbohydrate concentration increased substantially as the fruit ripened so that 16.8% of the energy requirement (recommended daily allowance, RDA) for six‐month‐old infants would be met by 100 g of the fresh pulp. Although vitamin C content decreased at maturation, 7% of the RDA would be provided by 100 g fresh pulp.

The fruit was found to be very rich in macro‐ and micronutrients, and 100% of the six‐month infants RDA for K, Mn, Zn and Se would be satisfied with 100 g of fresh pulp. This amount of pulp would also provide 86%, 57%, 24% and 12% respectively of the Mg, Cu, Fe and P RDA. P and Mg were found to be more highly concentrated in the ripe than in the unripe fruit whereas the reverse was the case for Ca and Se. Aspartic acid, glutamic acid and leucine were the major amino acids in the ripe fruit and respectively constituted 13.1, 12.5 and 7.9%, of the total. The concentration of essential and non‐essential amino acids was much higher than that in a commercial banana. Twelve of the 17 amino acids analysed were more concentrated in the mature compared with the green fruit, and 11 of these were an order of magnitude higher than in M paradisiaca L banana. The results of the present study demonstrate that Musa ‘Bhimkol’ is a nutritious baby food.
Interaction of lipid in the maillard reaction between cysteine and ribose: The effect of a triglyceride and three phospholipids on the volatile products
Authors: Farmer Linda J , Mottram Donald S
Published: October 2006

The inclusion of phospholipid in the Maillard reaction between cysteine and ribose is known to modify the volatile aroma compounds produced. The contributions made to the headspace volatiles by 60 major products of this reaction have been compared for four different lipids and their effect on aroma quality noted.

The results described demonstrate marked dissimilarities between the behaviour of the four lipids. The most noticeable distinction was between the effect of triglyceride and the three phospholipids, but there were also variations in the way that each of the three phospholipids participated in the Maillard reaction. As well as displaying marked differences in volatile products, reaction mixtures containing the four lipids possessed distinct aroma characteristics; the phospholipids containing phosphatidylethanolamine conferred the most meat‐like odour. These differences appear to be caused by the dissimilar fatty acid compositions and polar moieties. Thus this study underlines the importance of lipid interaction in the Maillard reaction for the formation of flavour.
Energy of activation in cassava silages
Authors: Saucedo‐Castañeda Gerardo , Raimbault Maurice , Viniegra‐González Gustavo
Published: October 2006

The formation of lactic acid in cassava laboratory silos was determined at five temperatures using a strain of Lactobacillus sp as inoculant. The acidification kinetics were followed during the first 2 days. Dry matter, pH and other fermentation byproducts were also determined. The optimum temperature for the production of lactic acid was 30°C. Rate constants (k) were calculated by fitting each lactic acid curve to the Gompertz model and these were fitted to the Arrhenius equation and the energy of activation was calculated. An unusually low value for the energy of activation in biological systems was found (8300 ± 750 cal mol−1). The relatively high dry matter content (45% DM) in cassava silage could impose a type of barrier to diffusion of lactic acid. Local accumulation of lactic acid could affect the evolution of the biological reaction. Thus, this result could be explained by a diffusional limitation of lactic acid in the fermenting mass.
Changes in cell‐wall composition and degradability of sorghum during growth and maturation
Authors: Goto Masakazu , Gordon Alex H , Chesson Andrew
Published: October 2006

Samples of sorghum (Sorghum bicolor Moench × Sorghum sudanense Stapf, cv ‘P 988’) were harvested at five growth stages. Quantitative methylation and acetalation–methylation methods were used to examine changes during growth of cell‐wall polysaccharides, their association with phenolic compounds and the effects of changes on rumen degradability. Cellulose degradability, as measured by a nylon‐bag method, decreased from 82·5% at the youngest stage to 36·5% at the milk‐ripe stage, at a greater rate of change than degradability of dry matter. Among the monosaccharides contributing to cell‐wall polysaccharides, the degradabilities of arabinose and uronic acid residues were consistently higher than those of xylose and glucose, the main components of structural carbohydrates. Recovery of parent neutral sugars from cell wall polysaccharides, calculated as the sum of partially methylated alditols, was in good agreement with the values obtained by direct estimation of individual sugars as their alditol acetate derivatives. Total non‐starch polysaccharide content increased from 31·1% to 45·1% between the first two growth states, with little change evident thereafter. The relative proportion of individual to total sugars remained consistent throughout growth. The values for arabinose, xylose and glucose residues accounted for 4·9%, 27·9% and 63·0% of total neutral sugars, respectively. The pattern of glycosidic linkages detected could be mainly ascribed to the presence of (1–4)‐β‐D‐glucans (cellulose), arabinoxylan, (1–3)(1–4)‐β‐D‐glucans, (1–4)‐β‐D‐galactan, (1–3)(1–6)‐β‐D‐galactan, rhamnogalacturonan and, possibly, xyloglucan. The cellulose content of the five sorghums was, in order of growth, 14·3%, 21·8%. 22·3%, 21·2% and 22·0% of dry matter.

The ratio of the mixed‐linked g1ucan:cellulose decreased during growth. Arabinoxylan, the predominant hemicellulosic polysaccharide, was estimated to comprise about 33% of total neutral sugars consistently for all sorghum samples. Arabinose, found largely as terminal residues in the cell walls, carried various amounts of alkali‐labile substituents, particularly at position 0–5, depending on the growth stage of sorghum. The extent of 0–5 substitution was closely correlated with both the lignin content (total phenolics minus phenolic acids, r = 0·903) and with cellulose degradability (r = 0·915).