bluuebunny/crossref_metadata_2025 huggingface dataset:
Redistribution of minerals in apple fruit during storage: The effect of storage atmosphere on calcium concentration
Authors: Perring Michael A. , Pearson Keith
Published: October 2006

Calcium concentrations in median transverse sections of Cox's Orange Pippin apples stored at 4°C in either air or 1.25% oxygen (< 0.3% carbon dioxide) were measured at weekly intervals for 25 weeks. Large fluctuations of calcium concentration occurred in all zones of fruit from both stores throughout storage. The low oxygen atmosphere had little effect on the concentration of calcium in the cortex and redistribution of calcium from the core zone to the outer zones other than causing a decline in calcium concentration in the peel towards the end of storage when calcium concentration was generally rising in the peel of the air‐stored fruit. The results are discussed in relation to the suppression of calcium deficiency disorders by low oxygen storage and to earlier experiments on calcium redistribution and bitter pit development.
The relationship between HMW glutenin subunit composition and the bread‐making quality of British‐grown wheat varieties
Authors: Payne Peter I. , Nightingale Mark A. , Krattiger Anatole F. , Holt Linda M.
Published: October 2006

Based on previous work, which related individual HMW glutenin subunits to bread‐making quality by genetical analysis, quality scores were assigned to each of the commonly occurring subunits. The grain proteins of 84 home‐grown wheat varieties were fractionated by SDS—PAGE to determine their HMW glutenin subunit composition. The quality scores of each of the subunits were summed to create a Glu‐1 quality score for each variety. The results indicated that 47‐60% of the variation in the independently established bread‐making qualities of this set of varieties could be accounted for by variation in HMW subunits of glutenin. The presence or absence in the varieties of a translocated chromosome, which consisted of the long arm of 1B and the short arm of 1R from rye, was also established because of its known association with poor bread‐making quality. A correction factor was applied to the Glu‐1 quality score of those varieties that contained the 1 BLURS chromosome. The variations in the rye‐adjusted Glu‐1 quality scores were compared with those of the bread‐making qualities of the varieties, and the proportion of variation in quality accounted for was raised to 55‐67%. The Glu‐1 quality score and the biscuit‐making qualities of the same set of varieties were negatively related. The results are discussed in relation to future strategies recommended to wheat breeders for developing new varieties with improved bread‐making quality.
Ethanol production by fermentation of fruits and cladodes of prickly pear cactus [Opuntia ficus‐indica (L.) Miller]
Authors: Retamal Norma , Durán José M. , Fernández Jesús
Published: October 2006

Using prickly pear cladodes and fruits and different yeast strains of the genus Saccharomyces, both the chemical composition of the plant material and alcoholic fermentation were studied under controlled conditions. Before fermentation, fresh or previously dried cladodes were hydrolysed using cellulose or acid (HCl). The yield was determined by measurement of ethanol production by gas‐liquid chromatography. Two conversion indices, representing either the percentage of reducing sugars or the energy converted into ethanol, were considered. Using fresh or dried cladodes without fruits, the best results were always obtained after performing both types of hydrolysis. The enzymic method gave the highest sugar yield. However, ethanol production was similar to that obtained by acid hydrolysis of fresh cladodes, and only slightly higher than that of previously dried cladodes. The potential ethanol production that could be obtained from prickly pear cultivation in various regions (arid, semi‐arid and irrigated) is discussed.
Compositional changes in normal and mutant tomato fruit during ripening and storage
Authors: Richardson Christine , Hobson Graeme E.
Published: October 2006

Mutations that drastically slow down fruit ripening known as ‘ripening inhibitor’ (rin) and ‘non‐ripening’ (nor) have been incorporated by backcrossing into isogenic lines of the tomato cultivar, Ailsa Craig. F1 hybrids (rin/+ and nor/+) were then produced by crossing with the recurrent parent. The rates of deterioration of fruit from the hybrid plants were compared with those from the recurrent parent and a typical glasshouse cultivar, Sonatine. Levels of acids and sugars, and also the colour, firmness and dry matter content of the fruit, were measured at two selected stages of ripeness and after storage of the ripe fruit for 10 and 20 days at 20°C. Shelf‐life of the ripe fruit was also assessed. Although the acidity fell continuously from a high value early in ripening for all four lines, during storage that in the rin/+ was better and Sonatine was worse than average. Sugar levels generally peaked close to the red stage and fell thereafter, but much variability in this component was encountered. Both cv. Sonatine and Ailsa Craig overcoloured and lost firmness during storage, but the mutant lines survived well. The results suggest that the disadvantage of a high‐quality line such as Ailsa Craig in deteriorating quickly once the fruit are fully ripe can be partially overcome through the introduction of one of the ‘non‐ripening’ alleles.
A model system for studying protein binding to hydrophobic surfaces in emulsions
Authors: Brock Christopher J. , Enser Michael
Published: October 2006

A method is described for chemical modification of porous glass particles so that they are coated with a covalently linked layer of close‐packed, long chains of mixed alkyl and alkoxy types. This hydrophobic controlled‐pore glass is a useful model system for physico‐chemical studies of the hydrophobic interactions between proteins and fat particles in emulsions. Under non‐denaturing conditions non‐globular proteins (myosin, α‐, β‐ and χ‐caseins) bind more strongly than globular proteins (G‐actin, bovine serum albumin) in this system. Binding kinetics as well as binding strength are important in determining the composition of interfacial films in complex emulsions containing many proteins.
The influence of simple and condensed phenolics on the clarification of apple juice by honey
Authors: Wakayama Tada‐Aki , Lee Chang Y.
Published: October 2006

The rate at which polyphenolics of six apple cultivars were able to flocculate (coagulate) with honey proteins was compared. Condensed tannins were primarily responsible for the formation of the flocculates. The activity of tannins with honey proteins was high in the cultivars Red Delicious, Rome, and McIntosh (group A), and lower for the cultivars Jonathan, Golden Delicious, and Rhode Island Greening (group B). In order to understand the differences in clarification rates by cultivars, model systems were used to estimate the effect of simple polyphenolic compounds on the formation of insoluble tannin/protein complexes. The addition of chlorogenic acid or gallic acid to the systems containing honey proteins and tannic acid resulted in a significant decrease in the rate of formation of flocculates, whereas the addition of catechol to the above systems did not affect the flocculation time of tannic acid with honey proteins. A hypothesis is put forward to explain these results.
Reduced ruminai degradation of ryegrass caused by sulphur limitation
Authors: Millard Peter , Gordon Alex H. , Richardson Anthony J. , Chesson Andrew
Published: October 2006

Italian ryegrass was grown at a site low in plant‐available sulphur, with either 40 kg S ha−1 (S(+)) or no sulphur (S(−)) added. At the second cut after 8 weeks' regrowth, the S(−) grass had a lower concentration of sulphur while that of nitrogen was greater than in the S(+) grass. A greater proportion of the total nitrogen was recovered as amides in the S(−) compared with the S(+) grass. The S(−) grass also had a different morphology from the S(+) grass, with a reduced proportion of dry matter present as leaves and more found as flowers. The degradability of grass was determined by nylon‐bag measurements in the rumen of sheep fed either S(+) or S(−) grass. The S(−) grass had greater dry matter and cellulose degradabilities than the S(+) grass, irrespective of the sulphur status of the rumen. Continuously feeding the S(−) forage apparently reduced the ability of the rumen microbes to degrade both S(+) and S(−) grass. Amino acid analysis of grass residues recovered after rumen incubation showed that although the sulphur status of the grass influenced the loss of aspartic acid (present predominantly as asparagine), decreasing the sulphur status of the rumen had a greater effect—decreasing the loss of arginine, tyrosine, glycine, alanine, leucine, cyst(e)ine and methionine. Changes in the sulphur status of the rumen had no effect on the numbers of total viable or cellulolytic bacteria, but changing the diet to the S(−) grass increased the numbers of cellulolytic fungi.
Flavour perception of chloroanisoles in water and selected processed foods
Authors: Whitfield Frank B. , McBride Robert L. , Ly Nguyen T. H.
Published: October 2006

Sensory panels determined the flavour thresholds and supra‐threshold intensities of 2,4,6‐trichloroanisole, 2,3,4,6‐tetrachloroanisole and pentachloroanisole in various carriers. The threshold values for the chloroanisoles were 0.02‐1.4, 0.2‐5.8 and 3.2‐183 μg kg−1 respectively, depending on carrier. Threshold values increased for each chloroanisole in the order water, dried fruit, fruit buns and plain buns. These values have been taken to indicate the respective concentration levels at which the flavour of these carriers was affected by chloroanisole contamination. The increase in threshold values, from water to plain buns, was attributed to the relative amount of the lipid present in the carrier. The odour threshold of 2,4,6‐trichloroanisole in dried fruit is also reported.
A simple procedure for the quantification of intact linamarin in cassava and its products
Authors: Izokun‐Etiobhio Benjamin O. , Oraedu Alex C. I. , Ugochukwu Emmanuel N.
Published: October 2006

A thin‐layer chromatographic method coupled with a colorimetric technique for the quantitative determination of linamarin is described. The procedure is based on the measurement of hydrogen cyanide released by linamarase hydrolysis of linamarin isolated on the chromatogram. The released HCN is determined by a modified alkaline picrate method employing Conway vessels. The procedure is free from interferences associated with previously described methods and its sensitivity permits as little as 0.8 μg linamarin (≡0.09 μg HCN) to be determined.
Observations on the vinification of tea extracts
Authors: Ekanayake Athula , Chandradasa Palipana B.
Published: October 2006

Both clarified and unclarified aqueous tea extracts were subjected to fermentation by Saccharomyces cerevisiae var. Montrachet and by Saccharomyces bayanus after sweetening with sugar to 20° Brix. The theaflavin, caffeine and theobromine levels in the fermenting must fell progressively during 15 weeks. The soluble amino acids were reduced by >90% with S. bayanus in 1 week in the presence of added ammonium phosphate. The thearubigins remained unchanged. Marked astringency development was attributable to changes in the proportions of the soluble tea constituents. A few weeks of racking in barrels made of Berriya cordifolia reduced the astringency at the cost of liquor body. Interactions between oxidised polyphenols and proteins/polysaccharides were observed.
The growth of winter wheat on restored land in response to drainage and nitrogen availability
Authors: King John A. , Evans Eric J.
Published: October 2006

The effects of drainage on the growth and yield of winter wheat established on restored opencast land were studied within a rotation experiment over a period of four years. Previous cropping significantly influenced yields during the third and fourth seasons of the trial. As a result of drainage, grain yields were considerably improved, largely due to increased leaf canopy development, particularly during early spring. Higher concentrations of extractable soil nitrogen, coupled with a more extensive root system, were largely responsible for enhanced nitrogen uptake.
The effect of rice pollard and manganese levels in the diet on egg weight, shell quality and performance of crossbred layers
Authors: Karunajeewa Hector , Tham Sing H.
Published: October 2006

In two 2×4 factorial experiments the laying performance of 768 White Leghorn×Australorp hens given diets based on either meat and bone meal (MBM) or soya bean meal (SBM) as the principal protein supplements, each supplemented with either four levels (0, 80, 160 and 240 g kg−1) of rice pollard or four levels (85–74; 93–105; 113–122 and 136–141 mg kg−1) of manganese, was measured. In both experiments, the hens given the SBM diets laid heavier eggs with lower yolk colour than those given the MBM diets. The inclusion of 80 g kg−1 or more of rice pollard in either MBM or SBM diets increased egg weight and the percentage of 65 g and 60 g grade eggs. The egg weight response to diets with 160 and 240 g kg−1 rice pollard was not greater than that for diets with 80 g kg−1 rice pollard. Rate of lay was reduced and body weight increased on diets with 80 and 160 g kg−1 rice pollard but not on the diet with 240 g kg−1 rice pollard. Feed conversion efficiency was higher on the diets with 160 and 240 g kg−1 rice pollard than on the other diets. Rice pollard reduced yolk colour on MBM diets. The specific gravity of eggs on the diets with rice pollard was higher than on the control diets. Increasing the dietary level of rice pollard increased the concentration of linoleic and arachidonic acids and reduced that of palmitic, palmitoleic and oleic acids in egg yolk lipids. Increasing levels (74 to 141 mg kg−1) of manganese in the diet had no significant effect on either egg production or egg shell quality characteristics.
Chicken pancreatic enzymes for clinical use: Autoactivation of the proteolytic zymogens
Authors: Madhusudhan K. T. , Mokady S. , Cogan U.
Published: October 2006

The potential of chicken pancreatic enzymes for use as digestive aids was investigated. Frozen chicken pancreas was pulped and the enzymes were extracted at pH 8.0 and 6.0. The extracts were incubated for 165 h at either 0 or 5°C in order to induce autoactivation of the proteases. Extracts at pH 8.0 showed a faster activation rate of trypsin up to 85 h compared with pH 60 extracts, and pH 60 extracts showed a slightly higher trypsin activity upon termination of the incubation period. Higher initial chymotrypsin activity and total proteolytic activity were observed in pH 8.0 than in pH 6.0 extracts. Chymotryptic and total proteolytic activity showed a similar pattern, reaching maximal levels after 42 h incubation. Lipase and amylase activity declined with the increase in proteolytic activity.
Metal contents of some cocoa beans produced in Ondo State, Nigeria
Authors: Olaofe Olorunfemi , Oladeji Eunice O. , Ayodeji Omotunde I.
Published: October 2006

The metal contents in 11 cocoa samples collected from different parts of Ondo State, Nigeria, were determined by the use of atomic absorption spectrophotometry. The moisture and ash contents of the samples were in the range 2.0–3.2% and 2.0–3.8%, respectively, the means being 2.5% and 2.9%, respectively.

The mean contents of calcium, magnesium, potassium, sodium, manganese, iron, copper and zinc were 25.5, 5170, 2480, 21, 17, 15.8, 8.2 and 62 μg g−1, respectively of cocoa bean as purchased. Magnesium was present at much higher levels than the other metals. In some cases the difference between the mean metal content of samples was significant.
Spoilage of European hake (Merluccius merluccius) in ice
Authors: Pérez‐Villarreal Begoña , Howgate Peter
Published: October 2006

Batches of gutted European hake (Merluccius merluccius) were stored for up to 21 days in ice. A scale for the sensory assessment of freshness was developed. Changes in total volatile bases, trimethylamine and adenine nucleotide decomposition products were measured and found to correlate highly with the sensory scores. Microbiological changes were measured by total viable count at 20°C, pseudomonad count and count of H2S producers. The counts were highly correlated with the sensory score.
Evaluation of acid and Enzyme hydrolytic methods for the determination of cassava starch
Authors: Rickard June E. , Behn Kevin R.
Published: October 2006

The starch contents of three cultivars of cassava were determined in cooked and uncooked samples with and without removal of alcohol‐soluble solids. Hydrochloric acid and amyloglucosidase methods of hydrolysis were used. Hydrolysates were analysed using glucose‐specific (glucose oxidase) and non‐specific (ferricyanide reduction) methods. Statistical analysis of the results obtained indicated that there were no significant differences between the methods of hydrolysis and sugar analysis. The increased cost of using an enzymic method of starch analysis appears not to be justified for the determination of starch in cassava, unlike a number of other starch sources. The starch values obtained by enzymic hydrolysis of uncooked samples were significantly lower than for cooked samples. The percentage of uncooked cassava starch susceptible to enzymic degradation varied with cultivar from 14.0 to 46.88%. In view of the use of unprocessed/ungelatinised cassava chips or partly gelatinised cassava pellets for animal feed, further research into cultivar variation of starch susceptibility to enzymic degradation is required.
Amino acid composition of wheat grain. 1: Changes during development
Authors: Molino Isabel M Martín Del , Rojo Bárbara , Martinez‐Carrasco Rafael , Pérez Pilar
Published: October 2006

The changes in the composition of free and total amino acids in wheat grain during development are described: the experiment was performed in a growth chamber with three varieties of winter wheat (Triticum aestivum L.): Splendeur, Hobbit and Maris Huntsman. The changes in the total composition of amino acids of the grain as development progressed were consistent with an increase in the proportion of storage proteins. At 15 days after anthesis, the relative amount of glycine increased, suggesting that at this moment the proportion of gliadins was relatively low. The relative amount of arginine increased in mature grain, showing that at times close to maturity the relative proportion of synthesis of a protein fraction rich in this amino acid increased. Free glutamate, proline and arginine decreased at 15 days to a greater extent than the other amino acids and was present in low relative amounts during the period of maximum protein synthesis in the grain; these three amino acids could be the most limiting for protein synthesis in grain. In the free fraction the following showed a similar pattern of change during grain development: aspartate, arginine and histidine on the one hand, and on the other alanine, valine, leucine, isoleucine, threonine, phenylalanine and tyrosine; moreover both groups were inversely correlated. Glycine and lysine were directly related to each other and inversely to glutamate.
Digestibility of amino acids in soya‐bean, sunflower and groundnut meal, measured in pigs with ileo‐rectal anastomosis and isolation of the large intestine
Authors: Green Simon , Bertrand Solange L. , Duron Madeleine J. C. , Maillard Roland
Published: October 2006

Each of four littermate male pigs of 25 kg liveweight was surgically adapted to create a bypass of the large intestine by ileo‐rectal anastomosis. The large intestine was sealed at both ends and a cannula was exteriorised from the lumen to allow any products of residual fermentation to escape. Ileal digesta were excreted via the anus. Three isonitrogenous diets were formulated containing soya‐bean or groundnut (dehulled) or sunflower (not dehulled) meals as the sole protein sources. Each diet was fed, in turn, for 7 consecutive days to all pigs, and Heal digesta from feeds on days 5 and 6 (indicated by chromic oxide addition to feeds) were collected. This procedure was conducted twice for each diet. Apparent digestibility coefficients (AD) of nitrogen (N) and amino acids were calculated (as percentages of the respective intake). AD of N and the majority of amino acids of soya‐bean and groundnut meals were greater (P<0.05) than those of sunflower meal. In the order soya‐bean, groundnut and sunflower meal, coefficients were: for lysine, 87.7, 83.5, 71.0% (standard error of the differences between means (SED) 1.06); for threonine, 81.0, 80.5, 74.4% (SED 1.03); for methionine, 89.1, 84.9, 88.5% (SED 0.49); and for the sum of the amino acids, 85.4, 88.1, 78.8% (SED 0.75).
Near infra‐red analysis: The use of multivariate statistics for investigation of variables in sample preparation and presentation of tea leaf
Authors: Grant Alex , Franklin Jeremy G. , Davies Anthony M. C.
Published: October 2006

A data analysis procedure involving principal component and canonical variate analyses was used to investigate the effects of three sample variables (particle size, temperature and sample rotation) on the near infra‐red spectra of six teas of different geographical origin. The effects of milling method were shown to be much larger than those of sample temperature or rotation. The analysis provided a rational basis for the choice of a milling technique and sample presentation for a study of the possible relationship between tea quality and near infra‐red spectroscopic data.
Freezing of alfalfa leaf juice. Formation and solvent extraction of freezing curd
Authors: Hernandez Amelia , Martinez Carmen , Gonzalez Gaspar
Published: October 2006

Alfalfa leaf juice obtained after mechanical fractionation of whole plants was conserved by frozen storage. The freezing produced a curd whose amount was independent of freezing storage time. The curd contained 50% of the dry matter and 60% of the nitrogen in the original juice. Electron microscopy showed that the curd was mainly chloroplasts. The curd separation resulted in a poor recovery of protein concentrate from the thawed juice. The efficiency of acetone and propan‐2‐ol in removing lipids and pigments from the curd was studied; all extractions were at the boiling point of the solvent. Propan‐2‐ol extracted the most lipid, 42% dwb, acetone 28% dwb. The two solvents extracted pigments with similar efficiency. The curd extracted with propan‐2‐ol produced an almost colourless protein concentrate.
Survival of bromate and bromide in bread baked from white flour containing potassium bromate
Authors: Osborne Brian G. , Willis Kenneth H. , Barrett Gillian M.
Published: October 2006

The amounts of potassium bromate surviving in bread made using the Chorleywood Bread Process were less than 006 mg kg−1 (the current limit of detection) when this substance was added to flour at levels up to 75 mg kg−1 on flour weight; even when the addition level reached 100 mg kg−1, only 0.22 mg kg−1 was found in the bread. Within the limits of experimental error all of the added potassium bromate not detected unchanged in the bread was accounted for in the form of bromide.
Effect of phospholipid on the formation of volatile heterocyclic compounds in heated aqueous solutions of amino acids and ribose
Authors: Whitfield Frank B. , Mottram Donald S. , Brock Susan , Puckey David J. , Salter Linda J.
Published: October 2006

The concentrations of 68 heterocyclic compounds produced by heating a series of amino acid—ribose and lecithin—amino acid—ribose reaction mixtures at 140°Cfor 1 h were measured, after headspace collection on Tenax GC, by capillary gas chromatography—mass spectrometry. The amino acids studied were glycine, lysine and cysteine, and the classes of heterocyclic compounds quantified were pyrazines (14), pyridines (7), furans (14), thiophenes (26) and thiazoles (7). The studies showed that the addition of lecithin to the simple Maillard reaction mixtures led to a reduction in the concentrations of many of the heterocyclic compounds formed in these reactions. These findings support an earlier observation that phospholipids in foodstuffs, such as meat products, could exert a quenching effect on the amount of heterocyclic compounds formed in Maillard reactions during the cooking of food. A number of volatile compounds formed by the reaction of lipid degradation products with Maillard reaction intermediates were also identified.
Total amino acids and fatty acids composition of yam (Dioscorea) tubers and their evolution during storage
Authors: Kouassi Bohoussou , Diopoh Jacques , Leroy Yves , Fournet Bernard
Published: October 2006

The qualitative and quantitative analysis of total amino acids from tubers of six yam species (Dioscorea) and fatty acids from five yam species has been done by gas—liquid chromatography. For amino acid analysis, the results obtained show that hydrochloric acid hydrolysates of yam flours contain most of the amino acids from proteins in high concentration. In the fatty acid analysis, 11 saturated fatty acids, with 12 to 25 carbon atoms, and five unsaturated fatty acids, with 16, 18 or 20 carbon atoms, were identified. Palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and linolenic acid (18:3) are the most abundant fatty acids found in yam tubers. Comparative analysis of yam tubers stored for 1, 5 and 8 months after harvest shows that the total amino acid content decreases slightly and fatty acid content increases during the storage period. No significant change was observed in the composition of total amino acids and fatty acids from yam tubers stored at 25°C for several months.
Reversed‐phase high‐performance liquid chromatographic determination of inosine 5′‐monophosphate dephosphorylation in turbot muscle during storage in different chilling and freezing conditions
Authors: Okki Saadoun El Hadef El , Mazzocut Dominique , Mouthon Gilbert
Published: October 2006

Reversed‐phase high‐performance liquid chromatography was used to study post‐mortem variation in dephosphorylation of inosine 5′‐monophosphate and accumulation of its breakdown products in turbot (Scophthalmus maximus) muscle during storage at low temperatures. The relative concentrations of these compounds can be used as an index of freshness. Nucleotide decomposition and nucleoside and base accumulation are influenced by the following storage conditions: chilling at 4°Cfor 1 to 15 days; freezing for 15 days of pre‐ or post‐rigor muscle at various temperatures between ‐10 and ‐196°C; and quick or slow thawing.
Acid phosphatase in the tubers of Dioscorea species and its purification from the white yam (D. rotundata poir)
Authors: Ikediobi Christopher O. , Egwim Isaac C. , Ikoku‐Ogbonna Aku
Published: October 2006

Acid phosphatase activity was determined in 15 cultivars from four species of yam. A 12‐fold purification of the enzyme from Dioscorea rotundata (cv. chikakwondo) gave a homogeneous preparation as demonstrated by polyacrylamide gel electrophoresis. This enzyme preparation has an apparent molecular weight of 115 000 ±2000 and an optimum activity at a pH of 5·20 and a temperature of 50°C. The Km of the enzyme is 3·81 mM with disodium p‐nitrophenylphosphate (p‐NNP) as a substrate. The energy of activation, heat of activation, energy of inactivation and heat of inactivation are 7·0, 6·4, 4·41 and 4·34 kcal M−1, respectively. Although it has very little activity with most organic phosphoric acid esters, it is significantly inhibited by Ca2+, Hg2+ and EDTA and activated by Mg2+. The enzyme has a half‐life of 50,17 or 13 days, respectively, when stored at 6‐8°C, 0°C or room temperature (29±2°C).
Interference by formaldehyde in the 2‐thiobarbituric acid test for rancidity
Authors: Careche Mercedes , Tejada Margarita
Published: October 2006

The 2‐thiobarbituric acid (TBA) test is often used to detect oxidative rancidity, although certain limitations of the technique have been described. This study was of formaldehyde (FA) interference in the TBA test in model systems involving various concentrations of malonaldehyde (MA), FA and TBA.

At a TBA concentration of 20 μmol ml−1 it was found that FA could give rise to turbidity or precipitation. However, as the amount of MA in the reaction mixture increased (10 to 400 times higher than the upper limit of the standard curve), higher FA concentrations were required. Turbidity or precipitation resulted in fluctuating readings, and centrifugation or filtration lowered the readings (532 nm) to below those obtained when no FA was present. The ratio of TBA to MA must be ⩾1000 for full colour development, and hence lack of colour may be due to the TBA acting as a limiting factor in the reaction.

The presence of a peak at 323 nm and/or turbidity or precipitate confirmed of the reaction between FA and TBA. FA competed with MA for TBA thereby lowering the effective TBA:MA ratio. Other TBA‐reacting substances (TBARS) present in the medium may augment this effect.
Free and bound triacontanol in tea leaves
Authors: Narayan Mandayam S , Bhattacharya Binayak , Dhanaraj Nagalakshmi , Seshadri Ramachandran
Published: October 2006

A direct gas chromatographic method of identification and determination of 1‐triacontanol, a plant growth substance, in tea leaves is reported. Treatment of the tea leaves with calcium oxide releases more triacontanol, showing that the compound occurs also in a bound form in tea leaves.
Laboratory studies on vacuum and inert gas packing for the control of stored‐product insects in foodstuffs
Authors: New John H , Rees David P
Published: October 2006

Cowpeas, wheat flour and wheat grain infested with various developmental stages of, respectively, Callosobruchus maculatus (F) (Col: Bruchidae), Tribolium castaneum (Herbst) (Col: Tenebrionidae) and Rhyzopertha dominica (F) (Col: Bostrichidae) were packed under vacuum or in CO2 or N2atmospheres in plastic laminate pouches. After holding for up to 35 days the packs were opened and their contents incubated to allow survival to be assessed.

Almost all eggs of C maculatus were killed when vacuum packed at chamber pressures of II kPa or less and held under vacuum for 14 days, whereas about 7% of young larvae survived these conditions. In contrast, R dominica was more difficult to control when packed as eggs; about 10 % and 2% of eggs laid survived to adulthood after two weeks following packing at II kPa and 0·9 kPa, respectively, whereas larvae and adults were all killed. Populations of T castaneum eggs, larvae and adults were effectively controlled by vacuum packing at 11 kPa and holding for 7 days.

None of the insects tested survived being packed in a CO2 or N2atmosphere and held for periods ranging from 4 to 14 days.

Many C maculatus survived vacuum and gas treatments when polyethylene film was used as packaging material. Control failures also occurred when pouches were punctured either by the commodity or by insects.
Electrical stimulation and ageing of carcasses from red, fallow and New Zealand wapiti‐type male deer
Authors: Drew Kenneth R , Crosbie Stuart F , Forss David A , Manley Timothy R , Pearse Anthony J
Published: October 2006

Farmed male red deer (15 and 26 months), fallow deer (16 months) and New Zealand wapiti‐type deer (26 months) slaughtered in an experimental abattoir were used to determine the influence of processing practices on tenderness and pH. Carcasses were electrically stimulated (low voltage) through the leg or anus immediately after bleeding and compared with non‐stimulated carcasses.

Portions of loin and leg from all carcasses were subjected to a range of conditioning and ageing treatments before tenderness assessment was done with a Warner‐Bratzler shear press. Tenderness was measured in some samples after a freeze and slow thaw cycle.

Electrical stimulation in all deer types had a highly significant effect in improving tenderness and the effects were most dramatic when carcasses were placed in a chiller 2 h after slaughter. Conditioning and ageing regimes (maximum 96 h post‐slaughter) further improved tenderness, particularly in non‐stimulated carcasses. Processing effects were more marked in loin pieces; these cooled more rapidly than leg.

The process of freezing and slow thawing (20 h at 4°C in loins and 24–96 h at 0°C for legs) improved tenderness by 10–40% when compared with unfrozen pieces.

There were highly significant reductions in the pH values of legs due to stimulation as measured during the early stages after slaughter. A decline in pH with time post‐slaughter was also evident. The results were consistent with the post‐slaughter pH profile of loins. Electrical stimulation, via either the leg or the anus, gave similar results. An exception was the loin pH measurement from anally stimulated wapiti stags which appeared higher than their leg‐stimulated counterparts.

Where data were collected from both sides of leg‐stimulated carcasses, pH values were around 0.13 units lower for the stimulated shackled leg than for the free leg.

Leg temperatures rose to over 40°C at 0.5 h post‐slaughter in all deer. Temperatures were generally similar between stimulated and non‐stimulated carcasses for both loin and leg data.
Organic solvent pretreatment to enhance enzymic saccharification of straw
Authors: Katrib Fouad Al , Chambat Gerard , Joseleau Jean‐Paul
Published: October 2006

Enzymic saccharification of wheat straw in the absence of any pretreatment was only about 20 %. Acid hydrolysis did not improve the overall cellulose enzymic breakdown, nor did pretreatment by flash autohydrolysis under pressure or sodium chlorite delignification. When wheat straw was treated with N‐methyl‐morpholine‐N‐oxide (MMNO) at J20°C for 20–30 min, this treatment and subsequent enzymic hydrolysis produced carbohydrate conversion of 73%. Similar results could be obtained by treating straw with 0·1 M sodium hydroxide. When MMNO treatment was combined with any other pretreatment, the saccharification yield was greatly enhanced. Nearly quantitative conversion was obtained by swelling straw in 0·1 M sodium hydroxide followed by MMNO treatment. The results show that lignin content of plant material does not represent the limiting factor to enzymic saccharification.
Volatile aroma constituents of pepino fruit
Authors: Shiota Haruyasu , Young Harry , Paterson Vivienne J , Irie Mamoru
Published: October 2006

Volatile aroma constituents of pepino fruit (Solanum muricatum) were separated by simultaneous distillation and extraction (SDE). They were analysed by gas chromatography and mass spectrometry. Major components in the volatiles were 3‐methyl‐2‐buten‐1‐ol, 3‐methyl‐3‐buten‐1‐ol, 3‐methyl 2‐buten‐1‐yl acetate, 3‐methyl‐3‐buten‐1‐yl acetate, butyl acetate and (Z)‐6‐non‐1‐ol. In addition to the above, 3‐methyl‐3‐buten‐1‐yl 3‐methylbutanoate, 3‐methyl‐2‐buten‐1‐yl 3‐methylbutanoate, 3‐methyl‐2‐buten‐1‐yl 3‐methyl‐2‐butenoate and 3‐methyl‐3‐buten‐1‐yl 3‐methyl‐2‐butenoate have been identified as minor components. The last three compounds were previously unknown as natural products.

Aroma constituents from three cultivars, El Camino, Kawi and Suma, were compared with one another.
Equi‐protein substitution of cottonseed meal for groundnut cake in diets for weaner‐grower pigs
Authors: Ikurior Steven A , Fetuga Babatunde L A
Published: October 2006

Nigerian processed cottonseed meal was substituted for 0, 25, 50, 75 and 100 % portions of dietary groundnut cake on an equi‐protein basis. The diets were fed to 50 Large White and Large White × Landrace crossbed pigs from 13.9 kg average weight to 70 kg liveweight in a bi‐replicate single‐way classification trial. Average daily gain and average daily feed consumption were 0.51, 0.52, 0.53, 0.55 and 0.56 kg; and 1.67, 1.77, 1.85, 1.84 and 1.82 kg for the respective diets. Feed/gain ratios ranged from 3.25 to 3.49. No significant differences between diets were seen for either of these parameters. Neither the gross tissue nor the jointed carcass proportions were significantly affected by cottonseed meal substitutions. The mean fresh weights of the liver and lungs decreased with increasing levels of dietary cottonseed meal but the differences were not significant. None of the pigs showed symptoms of gossypol intoxication. The data suggest that some of the Nigerian‐processed cottonseed meals can be combined in various proportions with groundnut cake to supply protein, or used singly, up to 20 %, in diets for weaner‐grower pigs.
Solid‐phase extraction‐fractionation of alfalfa saponins
Authors: Oleszek W
Published: October 2006

A simple method was developed to isolate alfalfa saponins and fractionate them into medicagenic acid, hederagenine and soyasapogenol glycosides. This method is based on the selective extraction of saponins from a C18 solidphase column with methanol‐water solutions. Selectivity of the C18 sorbent to retain saponins strongly depended on the pH of the loaded sample. This characteristic was the basis of a new method of column chromatography for isolation of individual saponins.
Changes in activities of cell wall degrading enzymes during fermentation of cassava (Manihot esculenta Crantz) with citrobacter freundii
Authors: Okolie Paulinus N , Ugochukwu Emmanuel N
Published: October 2006

The cell wall degrading enzymes polygalacturonase (EC 3.2.1.15),pectinase (EC 3.1.1.11), cellulose (EC 3.2.1.4) and xylanase (EC 3.2.1.8), as well as α‐amylase (EC 3.2.1.1) and phosphorylase (EC 2.4.1.1), were monitored during fermentation of cassava (Manihot esculenta Crantz) with Citrobacter freundii. All the enzymes were detected in cassava at the start. During fermentation, initial decreases in polygalacturonase, cellulase and xylanase were followed by increases which peaked as the tissue softened. There were significant (P<0.05) increases in pectinase, xylanase, cellulase, polygalacturonase and phosphorylase in inoculated cassava and the fermentation medium relative to controls (uninoculated cassava and medium) during the softening period. The control cassava did not ferment, indicating that the textural changes in inoculated cassava were due to enzymes secreted by C freundii. Studies on the effect of enzyme inhibition on fermentation showed that the pectic enzymes and cellulase were of primary importance and that inhibition of α‐amylase and phosphorylase had no effect on the process.
Use of species‐specific antisera to adrenal heat‐stable antigens for the identification of raw and cooked meats by agar gel diffusion and counter immunoelectrophoretic techniques
Authors: Sherikar Adagonda T , Khot Jayakumar B , And Bhushan M Jayarao , Pillai Shreekumar R
Published: October 2006

Rabbit antisera to adrenal heat‐stable and ethanol‐precipitable antigens of buffalo, cattle, sheep, goat and pig were used to develop an agar gel precipitation test and a counter immunoelectrophoretic method for the identification of homologous species in raw, partially heated and boiled meat extracts. Immunoabsorption was necessary to make the primary antisera species specific. The specific antisera can be recommended for identification of the species of origin of meats and their mixtures (5‐10% adulteration) in raw, partially heated and cooked states even in the case of closely related species, viz cattle and buffalo, sheep and goat.
The interaction of zinc(II) and phytic acid with soya bean glycinin
Authors: And Neil Nosworthy , Caldwell Robert A
Published: October 2006

Binding of phytic acid to Zn(II) free glycinin was not observed in 0.5 M KCl at pH 6.2. The addition of varying quantities of phytic acid to a Zn(II)‐ glycinin system at pH 6.2 ([KCl]=0.5 M) initially resulted in binding of phytate and increased binding of Zn(II) to glycinin probably as a phytate‐Zn(II)‐glycinin complex. Further addition of phytate resulted in precipitation of zinc and protein. Bovine serum albumin also showed increased affinity for Zn(II) owing to the presence of phytic acid.

Phytic acid‐Zn(II) precipitates have a capacity of removing glycinin from solution, presumably by surface adsorption. The presence of soluble Zn(II) inhibits this adsorption. Bovine serum albumin is removed from solution by phytic acid‐Zn(II) precipitates only when soluble zinc is present.
Changes in organic acids in chilled tomato fruit (Lycopersicon esculentum Mill)
Authors: Thorne Stuart N , Efiuvwevwere Bernard J O
Published: October 2006

Mature green tomatoes cv Calypso were stored at 5, 7,12 or 19oC for 0,3,9, 12 or 21 days, then ripened at 19oC for 3 or 6 days before analysis for organic acids, pH and acidity. Citric acid concentration increased after storage at 5 or 7oC and decreased at 19oC. Malic acid decreased at all temperatures with the greatest decrease occurring at 19oC. The malic/citric acid ratio was 0.32 at 19o C and 0.36 at 12oC. The rate of acetic acid accumulation increased as the storage temperature was reduced. Oxalic acid concentration decreased with time but was greatest at 12oC and lowest at 19oC. Fumaric acid concentration showed similar but erratic trends. Changes in pH were variable, but greater in chilled than unchilled fruit. Titratable and total acidities increased with storage time at chilling temperatures, but decreased at 19oC. Bound acidity initially decreased with time but subsequently increased. Significant differences were found between organic acid concentrations and pH in chill‐damaged and undamaged tissue.
Ammonia (NH3) and total volatile nitrogen (TVN) in preserved and unpreserved stored, whole fish
Authors: Haaland Herborg , Njaa Leif R
Published: October 2006

Total volatile nitrogen (TVN), ammonia (NH3) and amide‐N were analysed in fish stored without and with preservatives. In well preserved fish the increase in NH3‐N during storage was accompanied by a parallel decrease in amide‐N. It is concluded that NH3 may originate from glutamine and probably also from asparagine. In unpreserved material other sources may dominate.
Purification of glutathione S‐transferase from lean pork muscle and its reactivity with some lipid oxidation products
Authors: Williamson Gary , Ball Sarah K M
Published: October 2006

Soluble glutathione S‐transferase was isolated from lean pork meat by S‐hexylglutathione Sepharose 6B. A single form of the enzyme with a subunit molecular weight of 24 800, a pH optimum of 6.2 and an isoelectric point of 7.6 accounted for the majority of the transferase activity. The pure enzyme is stable upon storage at pH 6, and has a relatively low Km (87 μM) for glutathione. Substrate specificity suggests membership of class Pi. Glutathione S‐transferase was able to reduce certain primary products of lipid oxidation. Linoleic acid hydroperoxides, for example, were converted to their corresponding hydroxides (specific activity = 260 nmol min−1 mg−1). The transferase could also inactivate secondary products of lipid oxidation. Trans,trans‐2, 4‐decadienal, which results from breakdown of lipid hydroperoxides, was chosen as an example of this class. A high specific activity (1400 nmol min−1 mg−1) was found for conjugation of the dienal with glutathione. It is suggested that endogenous glutathione S‐transferase functions as an antioxidant in stored muscle food by removing some of the reactive products that propagate the oxidation of lipids.
The nutritive value of native and modified lucerne juice for rats
Authors: Hanczakowski Piotr , Skraba Bogumila
Published: October 2006

An attempt was made to improve the nutritive value of lucerne juice as a protein source for rats. Diets, based on ground barley and lucerne juice, were supplemented with amino acids (methionine and/or lysine), polyethylene glycol (to neutralise phenolic compounds), cholesterol (to neutralise saponins), or fat. In one diet the content of calcium and potassium was lowered. Aerobic fermentation of juice with or without yeasts was also carried out. The biological value (BV) and true digestibility (TD) of proteins were estimated using the Thomas‐Mitchell balance method. The amino acid supplement improved the BV of protein from 52 to 57 as a result of its supplementary effect on barley rather than juice protein. The addition of polyethylene glycol (PEG) had an adverse effect on the nutritive value of the mixture (BV was reduced from 48 to 39). The BV of proteins was slightly lowered by aerobic fermentation with or without yeasts (control 42, 41 and 37, respectively) but differences were not statistically significant.

The effect of lucerne juice and casein on apparent digestibility of basal nutrients was also compared. Lucerne juice had an adverse effect on digestibility of all nutrients, especially fibre, and on availability of minerals, which may have been caused by changes in the caecum of the rats.
Varietal and geographic classification of French red wines in terms of elements, amino acids and aromatic alcohols
Authors: Etiévant Patrick , Schlich Pascal , Bouvier Jean‐Claude , Symonds Patrick , Bertrand Alain
Published: October 2006

Thirty‐four French red wines from three regions already studied for their anthocyanin and flavonoid constituents have been further analysed for elements, amino acids and aromatic alcohols. An interpretation of the differences between wines related to their different geographic and varietal origins has been made from the results of statistical analyses: F statistic, principal component analysis (PCA) and stepwise discriminant analysis (SDA).

Wine samples produced near Bordeaux were found to be characterised by higher rubidium and lower lithium and calcium concentrations. Differences between wine samples made from the same grape variety or produced in the same region are mainly related to differences in potassium and ash contents. The PCA demonstrates that the concentration of most amino acids in wines is mainly a function of the technology used in wine production. Moreover, it shows that the concentration of proline, hydroxyproline and ethanolamine are generally lower in wines prepared from Carignan, Cinsault and Grenache grapes than in wines from Cabernet Franc, Cabernet Sauvignon or Merlot grapes. Finally, it shows clear differences between wines according to the latitude of the production centre. These differences correspond to increasing total nitrogen content from south to north, ie Narbonne and Bordeaux versus Angers.

In discriminant analysis Bordeaux wines were characterised by high rubidium and low arginine concentrations, Angers wines by a lower arginine content and Narbonne wines by their abundance of magnesium and deficiency of ethanolamine.
Analysis of alkyl‐ and alkenylresorcinols in triticale, wheat and rye
Authors: Gohil Suresh , Pettersson Dan , Salomonsson Ann‐Christine , Åman Per
Published: October 2006

Alkyl‐ and alkenylresorcinols were extracted with acetone from whole kernels of wheat, rye and various triticales. The resorcinols were ethylated, analysed by GC on a capillary column and further identified by GC‐MS. Alkylresorcinols with chain lengths of C15, C17, C19, C21, C23and C25and pairs of isomeric C17, C19, C21, C23and C25alkenylresorcinols were quantified in all samples. The content of alk(en)ylresorcinols was highest in rye, intermediate in triticale and lowest in wheat. The relative composition of the resorcinols differed between grains, with a higher content of the C19alkylresorcinol in rye and of the C21alkylresorcinol in wheat.

Wheat and three lines of triticale were harvested at three stages of maturity after the grain filling period was ended (water content ∼40,30 and 20%). During this period of time the gross chemical composition, water extract viscosity, and content and relative composition of the alk(en)ylresorcinols, were relatively constant.
Changes brought about in solid substrates after fermentations of mixtures of cereals and pulses with Rhizopus oryzae
Authors: Blakeman J P , McCracken A R , Seaby D A
Published: October 2006

Fermentations of Rhizopus oryzae using a mixture of soya grits and rye flakes resulted in increases in protein content of up to 36% over a 96‐h incubation period. Increases in oil and nucleic acid were also recorded. The increase in protein content was largely explained by a decrease in dry weight of the fermented material. Increasing aeration in petri dishes used for fermentation did not affect protein content or weight loss. pH changes in fermented substrates were related to the nature of the ingredients used. A marked reduction in pH occurred when cereals were fermented. Three different methods for assessment of biomass in solid substrates are compared.