bluuebunny/crossref_metadata_2025 huggingface dataset:
Flour lipids and their effects in baking
Authors: MacRitchie Finlay
Published: November 2006

Wheat flour lipid was separated into five fractions by selective elution from silica gel. The two earlier eluted fractions, which contained mainly non‐polar components, depressed loaf volume when added to defatted flour. The three other fractions contained polar components and these maintained or increased loaf volume. The effects of the fractions as foam stabilizers paralleled their effects on loaf volume, supporting the theory that flour lipids exert their action in baking through their role as surfactants in stabilizing or destabilizing the gas bubble structure during expansion of the loaf. Evidence points to a classification of flour lipids into three groups according to their effects in baking. The polar galactolipids and phospholipids increase loaf volume, compounds of intermediate polarity depress loaf volume while the more non‐polar compounds such as triglycerides have little effect in the absence of other lipids but have beneficial effects when other lipids are present. Thin‐layer chromatography showed clear differences in composition between lipid extracts from wheat, rye and maize flours and these could be correlated with effects on the baking behaviour of defatted wheat flour.
A study of gluten extractability from doughs made from fresh and stored wheat flours
Authors: Patey Alan L. , Shearer George , McWeeny David J.
Published: November 2006

In contrast to the increase in protein extractability which normally occurs in making a dough from a flour, on overmixing dough from a freshly milled flour of good bread‐baking quality, a progressive reduction occurs in the amount of acetic acid soluble proteins whereas the protein solubility shows little change in equivalent doughs made from similar flours stored for several years. Addition of artificially aged flour lipid, addition of oleic acid or defatting all tend to make the fresh flour imitate the behaviour of stored flour. Addition of diacetyl tartaric acid ester of mixed monoglyceride (which improves baking properties) to a stored flour makes the protein extractability move towards that of a fresh flour. It is suggested that in making dough from a fresh flour, there is a progressive binding of fresh flour lipid by the high molecular weight flour protein, which subsequently causes insolubility of this protein and that this binding like other lipid‐protein interactions is a major factor influencing flour baking performance.
Complexes of the condensed tannins of sainfoin (Onobrychis viciifolia scop.) with fraction 1 leaf protein and with submaxillary mucoprotein, and their reversal by polyethylene glycol and pH
Authors: Jones William T. , Mangan James L.
Published: November 2006

In vitro studies were made to determine the nature of complexes formed between the condensed tannins (i.e. pro‐anthocyanidins or flavolans) of sainfoin (Onobrychis viciifolia) and either the major soluble dietary protein, Fraction 1 protein, of green leaves, or bovine salivary mucoprotein. Fraction 1 protein, uniformly labelled with 14C, formed only insoluble complexes with these tannins. Bovine salivary mucoprotein produced insoluble complexes only at temperatures below 25°C. Fraction 1 protein complexes were stable between pH 3.5 and pH 7.0. At pHs below 3.0 greater than 90% of the protein was solubilised in the presence of PEG but at pH 8.0 only 30% of the protein was released from the complex. In vivo experiments with sheep fed sainfoin, confirmed the stability of the tannin‐Fraction 1 complexes in the rumen (pH 6.5) and break‐up of the complexes in anterior duodenal samples (pH 2.5) as shown by the extractability of condensed tannin from the complex. The significance of these results with respect to (a) bloat in cattle, (b) nitrogen metabolism of ruminants, is discussed. Polyethylene‐glycol, mol.wt. 4000 (PEG) exchanged with protein in the complex releasing protein into solution. The effectiveness of PEG was dependent on the amount of tannin in the complex and the age of the complex at the time of addition of PEG. The results explain the observation that PEG is unsuitable as a marker for rumen volume determination when animals are fed herbage that contains condensed tannins. A method for determining any deleterious effects of tannins on nitrogen metabolism by ruminants, is suggested.
Nutritive value of oat and rye grain protein as influenced by nitrogen and amino acid composition
Authors: Eppendorfer Wilfried H.
Published: November 2006

In experiments with increasing applications of nitrogen to oats and rye grown in pots, grain with widely varying N‐content was obtained. In rye increasing N‐concentrations were associated with decreases in the protein of lysine and several other amino acids including threonine, tryptophan, methionine and cystine, whereas glutamic acid, proline and phenylalanine increased. In oat protein the amino acid composition was less affected by increasing N‐content in grain. Concentrations of most essential amino acids were higher in oat than in rye protein, especially at high N‐levels. The ratio lysine + arginine/proline was higher in oat than in rye protein and did not, as in rye, decrease with increasing N‐concentration. Lysine as a percentage of dry matter increased up to the highest N‐level in both cereals. In rat feeding experiments true digestibility of the protein of oats and rye increased to the same extent with increasing N‐concentration in grain, whereas the biological value of the protein decreased considerably in rye but only slightly in oats. Net protein utilisation decreased with increasing N‐content in rye but increased in oats.
Zinc, copper, lead and cadmium contents in green tea
Authors: Tsushida Tojiro , Takeo Tadakazu
Published: November 2006

The levels of zinc, copper, lead and cadmium in green tea have been determined by atomic absorption spectrophotometry. With the growth and development of tea shoots, zinc, copper, lead and cadmium concentrations decreased gradually. Some of the lead in green tea was eliminated by washing with water before manufacturing. The range and mean of the zinc, copper, lead and cadmium in 139 green teas were as follows: zinc, 23.4–100.5 and 54.4 μg/g; copper, 4.7–36.5 and 11.4 μ/g; lead, 0.11–1.93 and 0.49 μg; cadmium, 0.013–0.098 and 0.036 μg/g. Significant differences in the contents of copper and lead were observed among the different districts of the country. The green tea produced in some districts near the metropolis areas contained the highest concentration of lead.
An examination of some foodstuffs for the presence of volatile nitrosamines
Authors: Gough Terry A. , McPhail Morag F. , Webb Kenneth S. , Wood Beryl J. , Coleman Ronald F.
Published: November 2006

Over 500 samples of foodstuffs, including meat, fish and dairy products, vegetables, fruit and soups have been examined for the presence of volatile nitrosamines. Cooked complete meals were studied in order to assess the possibility of interactions of the constituents which could result in nitrosamine formation. The extracts of foods were subjected to gas chromatography and the presence of nitrosamines confirmed using on‐line high resolution mass spectrometry. The most frequently occurring nitrosamines wereN‐nitrosodimethylamine andN‐nitrosopyrrolidine which were present in many cooked bacon samples.N‐nitrosodimethylamine also occurred in some other meat products, but other nitrosamines were rarely found.N‐nitrosodimethylamine also occurred in fish and cheese, but neither this nitrosamine nor any other was found above the detection limit of 1 μg/kg in any of the other foods.
Measurement of oxidation of polyunsaturated fatty acids by spectrophotometric assay of conjugated derivatives
Authors: Fishwick Michael J. , Swoboda Peter A. T.
Published: November 2006

A procedure has been developed for measuring the extent of oxidative deterioration of polyunsaturated fatty acids. The method is based on the conversion of fatty acid hydroperoxides and compounds derived from them, oxodienes and hydroxydienes, to conjugated fatty acids with strongly chromophoric triene and tetraene structures. This is done in two steps in which reduction with sodium borohydride is followed by dehydration under acid conditions; the chromophores produced are measured by absorbance in the ultraviolet. The method has been investigated using methyl linoleate and methyl linolenate as model compounds. Dienoic fatty acid oxidation products give rise to a conjugated triene chromophore whilst the more polyunsaturated fatty acids form a conjugated tetraene chromophore. The sum of absorbance changes at 268 and 301 nm measure the degree of oxidation. The ratio of absorbance change at 301 nm divided by that at 268 nm varies from zero for a pure triene to 2.8 for a pure tetraene and is a measure of the type of polyunsaturated fatty acid being oxidised. The concentration of oxodiene component present in the original mixture may be estimated separately by the decrease in the 275 nm region during the reduction step.
Simple phenols and indoles in anaerobically stored piggery wastes
Authors: Spoelstra Sierk F.
Published: November 2006

Phenol, p‐cresol, 4‐ethylphenol, indole and skatole, which contribute to a large extent to the bad smell of piggeries, were estimated in anaerobically stored piggery wastes. p‐Cresol, indole and skatole were also found in freshly voided faeces. Phenol, p‐cresol and 4‐ethylphenol are present in the urine as their glucuronides. It was shown that upon contact of urine and faeces, the urinary glucuronides are hydrolysed almost instantly liberating phenols. This hydrolysis is caused by the high β‐glucuronidase activity of faeces. Protein degradation followed by transformation of tyrosine and tryptophane were found to be additional processes contributing to the accumulation of phenol, p‐cresol, indole and skatole during the anaerobic storage of piggery wastes.
Changes in the short‐chain carboxylic acid content and chemical oxygen demand of stored pig slurry
Authors: McGill Albert E. J. , Jackson Norman
Published: November 2006

The effects of sample size, temperature and duration of storage on the concentrations of short‐chain carboxylic acids (C2‐C5) and the chemical oxygen demand (COD) of pig slurry were determined. After initial maximum values shortly after storage commenced, the concentrations of acids declined to low steady values. The relative proportions of the acids present remained constant during storage possibly indicating a step‐wise decomposition process. Following agitation during the sampling procedure, the COD values remained fairly constant with greater oxygen depletion in the larger sub‐samples. Filtration of the supernatants of slurry sub‐samples produced marked decreases in both COD and acid content of the filtrate. The rate of oxygen loss and the production of maximum acid concentrations increased at higher temperatures. Changes in small storage samples (<500cm3) did not reflect the changes likely to occur under normal farm storage conditions.
The residual blood content of meat—A review
Authors: Warriss Paul D.
Published: November 2006

There seems to be no unequivocal experimental evidence to support the widely held view that the efficiency of bleeding out of slaughter animals affects the eating or keeping qualities of meat. Neither are the effects of different slaughter procedures on bleeding efficiency clear, due partly to confusion over the relationship between the residual blood content of meat and the amount of blood lost at slaughter and partly to differences in the methodology used by various authors. As yet no really accurate and specific technique for determining whole blood in meat has been described.
Relationship between oven and toluene dry matter in grass silage
Authors: Haigh Philip M. , Hopkins John R.
Published: November 2006

Dry matter (DM) contents of 205 silages were determined by toluene distillation and oven drying at 100°C. The toluene distillation method gave values up to 11% higher than the oven drying method, the largest differences occurring with silages of high volatile fatty acid concentration, low lactic acid concentration and high ammonia nitrogen content expressed as a percentage of total nitrogen. Highly significant (P < 0.01) correlations were shown between toluene dry matter and oven dry matter for various ranges of ammonia nitrogen, and equations are presented which allow toluene dry matter to be readily estimated on a routine basis for grass silage.
Studies on the mucilages extracted from okra fruits (Hibiscus esculentus L.) and baobab leaves (Adansonia digitata L.)
Authors: Woolfe Mark L. , Chaplin Martin F. , Otchere Gifty
Published: November 2006

Okra fruits and baobab leaves are just two examples of foods used to give a mucilaginous quality to West African food dishes. The mucilages were extracted from both foods and purified. Preliminary studies have been conducted to characterise the mucilages chemically, as well as study their viscous behaviour in relation to their use in West African dishes. Both mucilages are acidic polysaccharides with associated protein and minerals. Neither the quantity of protein nor minerals were significantly reduced during purification. The protein was not separated from the polysaccharide by either gel chromatography or disc electrophoresis. Hydrolysis of okra mucilage revealed that the polysaccharide was composed of galacturonic acid, galactose, rhamnose and glucose (1.3:1.0:0.1:0.1). Baobab mucilage on hydrolysis was found to contain mainly galacturonic and glucuronic acids with minor quantities of galactose, rhamnose, glucose and arabinose (11.7:11.3:1.0:0.6:0.4:0.1). The mucilages form viscous solutions at low concentrations (5–10 g/litre). They attain maximum viscosity in the neutral pH range. However, the mucilage solutions are not stable to heat and lose much of their viscosity when heated.
An automated procedure for the determination of soluble carbohydrates in herbage
Authors: Arthur Thomas T.
Published: November 2006

An automated procedure for the estimation of total soluble carbohydrate in water extracts of herbage is described. Addition of different sugars to grass extracts showed good recoveries (96.5–104.5%) for glucose, fructose, sucrose and fructosan. Analysis of sugar mixtures similar in composition to grass extracts also gave good recoveries (98.7–100%). The automated technique enabled 20 samples per hour to be analysed with a lower coefficient of variation (1.96%) than for a manual anthrone method (3.85%).
Removal of zinc residues from apple leaves by hydrochloric acid and leaching of other nutrients in the process
Authors: Orphanos Panayiotis I.
Published: November 2006

Leaves sampled from “Lord Lambourne”, “Starking Delicious” and “Golden Delicious” apple trees sprayed with zinc sulphate were treated in various ways (a detergent wash, an acid wash, a 10 min, or a 20 min soak in N‐HCl). Leaves which were soaked had the lowest zinc content, and this was attributed to “internal” zinc; the other treatments left behind more zinc, and the increase was attributed to “external” and/or easily leachable zinc. A single spray (0.3% ZnSO4. H2O) increased “internal” zinc contents to ∼50 parts/106, and three sprays to ∼150 Parts/106. Soaking the leaves in N‐HCl for 10 min leached out K, Mg and Mn but not N, P or Fe. As with zinc, soaking for 20 min did not, except in one case, leach out any additional amounts of nutrients. It is suggested that there may be an “easily leachable” fraction of K, Mg, Mn, and possibly Zn, which is removed from the leaves by the 10 min soak in N‐HCl.
Inhibition of nitrification by nitrapyrin, carbon disulphide and trithiocarbonate
Authors: Ashworth John , Briggs Geoffrey G. , Evans Avis A. , Matula Jiri
Published: November 2006

We have studied the behaviour of the nitrification inhibitors nitrapyrin (2‐chloro‐6‐trichloromethyl pyridine) and carbon disulphide (CS2), and of trithiocarbonate ion (CS32−). Solutions of Na2CS3 in water or aqueous NH3 are stable but when added to soil they decompose with evolution of CS2, which in laboratory tests was complete within hours. In field experiments each material was injected simultaneously with aqueous NH3 or aqueous urea. Nitrapyrin was held strongly on soil near the centre of the injected band of fertiliser N. It became fully effective only approximately two months after injecting grassland in November (1974 and 1975) with 375 kg N/ha, but approximately one month after injecting winter wheat with 100 kg N/ha in March (1976). In contrast CS2 itself, or CS2 generated by CS32−, diffused rapidly from the injected band and markedly inhibited nitrification for up to three months after injecting grassland and up to one month after injecting winter wheat, but had no effect on nitrification later. The main practical implication of the work is that liquid fertilisers supplying NH4‐N may, if mixed with a trithiocarbonate, be injected into grassland in autumn, without risk of substantial nitrate leaching during winter. This extends the period suitable for injection and eases congestion of work normally done in spring.
Cellulose acetate as a selective sorbent for limonin in orange juice
Authors: Chandler Bruce V. , Johnson Robert L.
Published: November 2006

Cellulose acetate as flake or powder is an efficient and selective sorbent for removing the bitter principle limonin from orange juice. Treatment of orange juice serum with powder (10 g/litre) removed 44–70% of the limonin content in less than an hour, at the same time removing relatively negligible amounts of hesperidin and ascorbic acid. Similar amounts of limonin could be removed by agitating the whole juice with cellulose acetate flakes held in open mesh bags which allowed contact between the enclosed flakes and the juice. Other materials, including related carbohydrate derivatives and polymers, were tested but only cellulose acetate butyrate shared the unusual sorptive properties of cellulose acetate.
Cellulase inhibition by tannins in the testa of field beans (Vicia faba)
Authors: Griffiths D. Wynne , Jones D. Iorwerth H.
Published: November 2006

The testa of field bean varieties with coloured flowers contained 4–8 % tannin (measured as total phenolics) compared with less than 0.6 % in the testa of white flowered varieties. The tannin present in whole beans was almost entirely contained in the testa. The presence of high levels of tannin reduced in vitro digestibility and solubility in cellulase solutions of the testa and addition of high tannin testa decreased the solubility of cotyledon protein in acid pepsin. Water extracts of the testa from coloured‐flower varieties inhibited the action of fungal cellulase and reduced the in vitro digestibility of white flowered testa and cellulose. A highly significant relationship (r= −0.93***) was found between the tannin content and solubility in cellulase of testa for a range of 24 varieties. It is concluded that the effect of testa tannins on in vitro digestibility can be mainly attributed to their effect on cell wall digesting enzymes rather than an effect on protein solubility per se.
The preferential formation of volatile N‐nitrosamines in the fat of fried bacon
Authors: Mottram Donald S. , Patterson Ronald L. S. , Edwards Robert A. , Gough Terry A.
Published: November 2006

Whole bacon rashers and the separated lean and fat components were fried in an electrically heated pan and the residues in the pan and the trapped cooking vapours analysed for N‐nitrosopyrrolidine and N‐nitrosodimethylamine. The fat produced 12 times more N‐nitrosopyrrolidine and six times more N‐nitrosodimethylamine than the lean. In all cases the largest proportions of both nitrosamines were recovered from the cooking vapours. Prolonged heating of lean did not increase amounts of the nitrosamines. The importance of the non‐polar lipid phase of the adipose tissue in nitrosamine formation was demonstrated by heating fat and lean components of bacon in a non‐polar heating medium when high levels of nitrosamines were produced from the lean as well as the fat.
The effects of chloride in fertiliser salts on crop seed germination
Authors: Bernard Tinker P. , Reed Lawrence , Legg Christopher , Højer‐Pederson Svend
Published: November 2006

Recent developments in production of chloride‐free fertilisers prompted a test of effects of chloride on seed germination in soil. NPK nutrient salt mixtures, based on KCl or KNO3, were tested at 5 rates, in soil at 0.1 or 1.0 bar water tension at 10°C; other experiments on wheat and maize also used 2 and 3 bar tension and 20°C. Salt and chloride sensitivity varied widely; lettuce, cauliflower and sugar beet were most sensitive to chloride, but wheat and maize were also sensitive at high rates, high temperatures and in dry soil. Germination was never better with chloride‐based than nitrate‐based mixtures.
The effect of metal ion content on the viscosity of gum ghatti
Authors: Jefferies Martin , Pass Geoffrey , Phillips Glyn O. , Zakaria Mat B.
Published: November 2006

Cold water extraction of gum ghatti gives a soluble gum and an insoluble gel. The two fractions were shown by potentiometric titration to have the same acid equivalent weight and to be largely in the salt form, with less than 10% in the free acid form. Quantitative analysis of the two fractions for metal ion content showed that the gel fraction was largely a calcium salt. The soluble fraction contains calcium, potassium, sodium, and magnesium. Precipitation of the calcium ions reduces the viscosity but the original viscosity is not restored by addition of calcium ions.
Some postharvest factors associated with the occurrence of chilling injury in banana
Authors: Olorunda Ayodele O. , Meheriuk Mike , Looney Norman E.
Published: November 2006

Unripe Cavendish banana fruits were stored at 5–7°C under normal or 0.14 normal atmospheric pressure for two weeks, with or without a continuous supply of ethylene, prior to ripening at 20°C. Pulp/peel ratio, colour index and production of volatile were measured following prestorage at chilling temperature, and after reaching ripeness at 20°C. CO2 and C2H4 production were also measured at 20°C. The results show that green fruits had lower pulp/peel ratios than treated green fruits while the reverse was true following ripening at 20°C. Yellow colour development was retarded by 5°C pretreatment, and low pressure storage had no noticeable effect on colour index. Prestorage at 7°C, however, improved colour development slightly. Acetates, butyrates and alcohol produced by fruits prestored at chilling temperature and 0.14 normal atmospheric pressure showed both qualitative and quantitative differences compared with those produced by non‐chilled fruits.
Studies on the essential amino acid composition, protein fractions and biological value (BV) of some new varieties of rice
Authors: Chavan J. K. , Duggal S. K.
Published: November 2006

The protein quality of newly evolved high‐yielding Indian varieties of rice, namely, Improved Sabarmati, Pusa 2‐21, Jaya and Padma has been evaluated and compared with an old existing popular variety i.e. Basmati‐370. All the new varieties were found superior in their limiting amino acid content (lysine, tryptophan and methionine) and the ratio of various fractions of proteins. The animal feeding tests for biological value (BV), true digestibility (TD), net protein utilisation (NPU) and utilisable nitrogen (UN) also showed their superiority over Basmati‐370.
Use of high performance liquid chromatography combined with fluorescence detection for the identification and estimation of aflatoxins and ochratoxin in food
Authors: Hunt David C. , Bourdon Ann T. , Wild Peter J. , Crosby Neil T.
Published: November 2006

A method has been developed for the separation, identification and estimation of six mycotoxins in foods at the μg kg−1 level. The food is extracted by using aqueous acetonitrile and the extract is then washed with 2,2,4‐trimethylpentane and any mycotoxins re‐extracted into chloroform. The extract is then purified using grooved t.l.c. plates coated with silica gel. After chromatography, any fluorescent bands are removed and examined by h.p.l.c. using a fluorescence detector. The method has been tested using a range of foods including total diet samples. Recoveries at twice the detection limit varied from 40 to 95%.
An enzymatic assay for the total cyanide content of cassava (manihot esculenta crantz)
Authors: Cooke Rodney D.
Published: November 2006

An enzymatic assay for the cyanide contents of cassava parenchymal tissue (peeled root), cassava peel or cassava leaves is described. The material is homogenised in orthophosphoric acid; filtered through glass‐fibre paper and aliquots of the filtrate are neutralised and incubated with exogenous linamarase for 15 min. The cyanogenic glucosides present are hydrolysed to free cyanide which is estimated spectrophotometrically. The acid extraction solution inactivates endogenous linamarase, and assay of aliquots without enzyme treatment gives the free (non‐glycosidic) cyanide contents of the extracts. The acid extracts are stable for at least 4 days at 4°C, and the steam‐distillation/aspiration of earlier methods is unnecessary. The detection limit is < 0.01 mg (0.1 parts 10−6) cyanide per 100 g fresh weight and peeled root, and 40‐50 samples per day can be handled easily. Analyses of eight cultivars indicated longitudinal and radial cyanide gradients in the roots, and the problem of sampling bulky roots is discussed.
Enzymic browning in green olives and its prevention
Authors: Ben‐Shalom Noach , Harel Eitan , Mayer Alfred M.
Published: November 2006

The browning of green olives, which results from mechanical injury, was followed by measuring the reflectance from the fruit surface at 545 nm. The process is enzymic, apparently catalysed by catechol oxidase. It could not be prevented by inhibitors of the enzyme or by reducing agents, due to the impermeability of the whole fruit to these compounds. Dipping the fruit in 0.4 % NaOH prevented the formation of brown spots following mechanical injury.
Artificial soil stabilisation of backfill in field drainage
Authors: De Boodt Marcel F. L. P.
Published: November 2006

Washed gravel, used as backfill, can be replaced by ordinary soil when treated with soil conditioners such as bitumen‐emulsion or a solution of either polyurethane or polyacrylamide. Laboratory tests show that when the backfill is treated with these solutions, it can be put on the drains immediately. When bitumen‐emulsion is used the backfill should be dried first. Further, it is shown that conditioned light soil used as backfill significantly decreases the silting‐up of the drains while conditioning heavy soils can increase their permeability by a factor of ten to 100.
The phenolics of ciders: Effect of cultural conditions
Authors: Lea Andrew G. H. , Beech Frederick W.
Published: November 2006

Ciders were produced from pot‐grown Dabinett apple trees under ‘fed’ and ‘unfed’ fertiliser regimes. The ciders from fed trees were less bitter and astringent than from those which were unfed, which was related to an overall decrease of some 17% in fruit phenolic concentration.
Collagen content of some Australian canned meats
Authors: Board Peter W. , Montgomery William A. , Rutledge Peter J.
Published: November 2006

Eleven manufacturers supplied 146 samples of canned corned beef, corned beef with cereal, ham, cured pork shoulder and comminuted ham products. All cans were analysed for salt, moisture, fat, protein and collagen. The mean collagen content ranged between 0.99 and 4.08%. These results are discussed in relation to current international interest in establishing minimum limits for collagen‐free meat protein in processed meat products.
The influence of slaughter method on the residual blood content of meat
Authors: Warriss Paul D. , Leach Thomas M.
Published: November 2006

The effect of slaughter method on the residual haemoglobin content of the M. longissimus dorsi and the amount of blood lost at exsanguination of sheep was investigated. The influence of stunning method (electrical, 90 V, or captive bolt pistol), pithing and bleeding‐out position were examined. Sheep bled lying lost more blood than those bled hanging and electrically‐stunned animals lost more blood than those stunned with a captive bolt pistol; pithing had no effect. The residual haemoglobin content of the muscle did not vary significantly between methods and there was no relationship between it and the amount of blood lost at slaughter.
A study of the need for fibre by the growing New Zealand white rabbit
Authors: Spreadbury David , Davidson John
Published: November 2006

New Zealand White rabbits, aged between 5 and 8 weeks, were offered diets based on oatmeal together with up to 500 g kg−1 of ground oat husk, or 500 g kg−1 of ground barley straw or 400 g of a purified cellulose. The rabbits gained about 40 g liveweight per day when fed a well‐balanced control diet (in which oatmeal, grassmeal, corn oil and fishmeal were the main constituents) and, apart from one occasion, there was no significant reduction in this rate of gain even when the diets offered contained up to 500 g kg−1 of these fibre sources. Food consumption increased from 80 g day−1 to 115 g day−1 as the acid detergent fibre concentration in the diet increased from 39 to 270 g kg−1. Digestible and metabolisable energy contents of the diets fell as the fibre concentration rose but the rabbits were able to adjust their intakes and maintain their daily metabolisable energy intakes constant at about 1100 kJ. The proportion of fat in the body dry matter fell as the fibre concentration in the diet was raised. A minimum dietary fibre content of 100 g kg−1 as measured by the acid detergent fibre or crude fibre techniques is suggested for optimum healthy growth.
Urinary creatinine and creatine excretion in pigs in relation to body weight and nitrogen balance
Authors: Duggal Surinder K. , Eggum BjøRn O.
Published: November 2006

In experiments with growing pigs highly significant correlations between body weight and urinary creatinine (r=0.98) or creatine (r=0.95) excretion, were found. Furthermore, creatine made up of 20‐25% total urinary creatinine + creatine excretion. Creatinine excreted (expressed as mg kg−1 body weight) was significantly (P< 0.001) higher in heavier pigs (approx. 75 kg) compared to pigs at 25 kg and urinary creatinine as a percentage of total urinary N‐excretion was significantly (P< 0.001) lower for pigs of 25 kg than for pigs of 53 and 75 kg, respectively. There was a significant positive correlation (P< 0.001) between N‐balance and creatine excretion in 25 kg pigs whereas the opposite was the case for 75 kg pigs.
Analysis of condensed tannins using acidified vanillin
Authors: Broadhurst Richard B. , Jones William T.
Published: November 2006

The acidified vanillin method for determination of plant tannins has been reassessed. Excluding light and controlling the temperature of the reaction mixture increased the colour stability of the vanillin tannin adduct. Selection of optimum concentrations of reactants and solvents enabled the method to be used in the range 5‐500 μg of condensed tannin with a precision and accuracy greater than 1 μg.
Free amino acids in germinated wheat
Authors: Tkachuk Russell
Published: November 2006

Wheat was germinated at three different temperatures (10, 16.5 and 25°C) to examine the changes in free amino acid levels. The free amino acid content after 122 h of germination was respectively 4 x, 10x and 7x that of the sound wheat at ‘0 h ’Glutamine and proline showed the largest increases. Proline increased 100‐fold during 122 h of germination at 16.5°C.
Some relationships between grain yield and grain protein of wheat experiments in south‐east england and comparisons with such relationships elsewhere
Authors: Benzian Blanche , Lane Peter
Published: November 2006

By adopting a uniform method of presentation, the interrelationship between grain yield, %N in grain and N uptake (or protein yield) from diverse experiments and surveys can be compared readily. All three variables can be shown together by plotting yield vs %N and adding the third variable in the form of hyperbolic lines representing equal N uptake (or protein yield). This method is used in two diagrams which display 2000 values derived from 124 experiments on winter wheat and 400 values from 41 experiments on spring wheat, conducted by Rothamsted Experimental Station over 20 years. Both scatter diagrams display well‐defined boundaries which have been emphasised by linking points along these boundaries to form ‘envelope curves ’For winter wheat the maximum yield was 9.5 t ha−1, the largest N concentration about 3% and the largest N uptake 170 kg N ha−1 (about 970 kg protein ha−1). Spring wheat had a maximum grain yield of 6.3 t ha−1, the largest N concentration was 3.1% and the largest N uptake 125 kg N ha−1. Four examples of other work set within the same framework show applications of our method of presentation. Results from a recent more homogeneous series of experiments in southern England (conducted by the Agricultural Development and Advisory Service), showing clear seasonal differences, are seen to lie within the envelope curve defined by the Rothamsted experiments. Further illustrations are taken from an experiment by the Plant Breeding Institute, Cambridge, comparing varieties of different bread‐making qualities, from work of the Nebraskan plant breeding team who have produced grain with larger protein content without sacrificing yield, and from survey data for England and West Germany.
A comparison of simple methods for estimating starch content of cassava roots
Authors: Wholey Douglas W. , Booth Robert H.
Published: November 2006

A comparison of simple methods for estimating starch content of cassava roots showed a strong relationship between root specific gravity and root dry matter content. In the absence of drying facilities a specific gravity balance appears adequate to separate root samples according to dry matter content. A strong relationship between root specific gravity and starch content was observed using a maceration/sieving technique. This relationship was close to a published relationship based on chemical analysis. Root dry matter content may be used as an indication of starch content but care should be exercised in using linear conversions until more information becomes available. Existing conversion tables from root specific gravity to starch content and the starch content calibrations on the Reimann balance used, grossly underestimated starch content of the samples analysed.
The fractionation and purification of gliadins by hydrophobic interaction chromatography
Authors: Caldwell Kathryn A.
Published: November 2006

The apolar nature of wheat gliadins has been studied. Apolar properties have been exploited to fractionate components by hydrophobic interaction chromatography and fractions have been analysed further by polyacrylamide gel electrophoresis. Experiments were carried out in pH 5.0 buffer in absence of additives such as urea or dimethylformamide. Gliadin was not retarded by ethyl or butyl agarose but showed a strong affinity for both the phenyl and octyl derivatives. The strength of the hydrophobic interactions was such that aqueous alcohol was required to achieve appreciable desorption. Even so, only two‐thirds of the bound gliadin could be eluted with aqueous ethanol alone; complete desorption required the presence of small concentrations of tetramethylammonium chloride. The elution of protein from columns followed the general order ω‐,β‐, α‐, and γ‐gliadin, respectively. This procedure provides a simple system for the fractionation of wheat prolamines under mild conditions. Results suggest that a higher degree of resolution may be attainable by further modification of experimental conditions. Interaction of gliadin with nonpolar groups covalently bound to agarose apparently reflects the presence of hydrophobic patches on the surface of the gliadin molecule.
The metabolism of fatty acids, methyl ketones and secondary alcohols by penicillium roqueforti in blue cheese slurries
Authors: King Richard D. , Clegg Geoffrey H.
Published: November 2006

A slurry system in which Blue cheese flavour was produced in six days was developed and used to study the metabolism of fatty acids, methyl ketones and secondary alcohols by Penicillium roqueforti. It was found that fatty acids inhibited lipolysis but that far greater quantities of methyl ketones were produced when fatty acids were added to the slurries than when fatty acids were produced by the lipolytic activity of P. roqueforti. Methyl ketones and secondary alcohols added to Blue cheese slurries in quantities ten times as great as those found in mature Blue cheese were broken down within 7 days And the presence of fatty acids did not appreciably inhibit this breakdown.
The collection of faeces and urine from steers
Authors: Smith Timothy
Published: November 2006

A metabolism crate to collect faeces and urine from steers has been designed to avoid the possibility of stress caused by harness. This consists of a raised platform under which are one faeces tray and two urine trays, urine running forward initially and then being conducted to a collection bottle. Faeces are collected in the faeces tray. Animals are held in the crate by a neck chain, the minimum amount of restraint being applied. The standing area and positioning of the trays are adaptable to the individual animal. The crates have been successfully used for a number of years.
Effects of nitrogen and sulphur fertilisers on the yield, N and S content, and amino acid composition of the grain of spring wheat
Authors: Byers Marjorie , Bolton John
Published: November 2006

Spring wheat (cv. Kleiber) was grown in three pot experiments in a soil containing 10 mg kg−1 KH2PO4‐soluble sulphur with different rates of nitrogen and sulphur fertilisers. Without added S the yields of grain dry matter and crude protein were either unchanged (glasshouse experiment) or significantly decreased by the N treatments (controlled environment experiments). With added S the N fertiliser increased the yields by 40–110%. The experiments produced grain with a wide range of N and S contents, the latter ranging from 0.06–0.21% on a dry matter basis. Grain from treatments giving the largest yields of dry matter and crude protein had a N:S ratio of about 15. The amino acid composition of the whole grain was changed significantly by the fertiliser treatments. When plants were grown without added S at the highest level of N the grain contained less than half the amount of cyst(e)ine and methionine (as % of total amino acid content) found in grain from plants given adequate amounts of S fertiliser. Grain from S‐deficient plants also had a much greater content of aspartic acid + asparagine but less threonine, leucine, isoleucine and lysine. The N:S ratio in grain from plants grown with insufficient S was well in excess of 15. The relation of these findings to the nutritive value of wheat as a feed and to the provision of enough disulphide bonding capacity for its use in bread‐making are discussed. Our results emphasise the necessity for having an adequate amount of S to balance the larger N applications now given to wheat to ensure that the grain is of the highest quality possible with any particular cultivar.
Lipid and autoxidative changes in cold stored cod (Gadus morhua)
Authors: Hardy Roy , McGill Alister S. , Gunstone Frank D.
Published: November 2006

A study of lipid changes during the frozen storage of cod confirms that the major change is that of lipolysis. Oxidation is extremely slow and occurs primarily in the phospholipid fraction. Nevertheless, sufficient oxidation takes place during cold storage to reduce the acceptability of the fish primarily through the production of hept‐cis‐4‐enal. The mechanism whereby hept‐cis‐4‐enal occurs is discussed.
Biochemical changes occurring during the manufacture of budu
Authors: Beddows Clifford G. , Ardeshir Arshes G. , Daud Wan Johari Bin
Published: November 2006

The changes that occur during the commercial production of budu, a Malaysian fish sauce were examined. It was shown that the maximum volume of liquid was produced after 140 days and that proteolysis continued to occur until 200 days when 56% of the insoluble fish protein had been hydrolysed into soluble form. The colour was produced early during the fermentation. The aroma constituents, ammonia and trimethylamine, were produced early in the fermentation process, but the volatile fatty acids did not appear when fresh fish (Stolephorus) was used for the fermentation. In the commercial production, n‐butanoic acid concentration remained constant during the fermentation but ethanoic acid did increase during the period. The salt concentration and the pH were approximately constant throughout, at 26% and 5.65, respectively.
Purification and changes in activities of tomato pectinesterase isoenzymes
Authors: Tucker Gregory A. , Robertson Neil G. , Grierson Donald
Published: November 2006

Changes in the isoenzymes of pectinesterase were studied during the development of normal tomato fruit and of fruit from two near isogenic lines containing the ‘Never ripe’ (Nr) and ‘ripening inhibitor’ (rin) alleles. Nr fruit ripen slowly to an orange‐red while rin is even more extreme, eventually turning yellow. Enzyme activity present in normal green fruit increases during ripening, as did that in Nr fruit. No comparable increase was observed in rin fruit. Pectinesterase activity was resolved into two major forms by ion‐exchange chromatography. One of these isoenzymes (PE 2) accumulated during the ripening of normal and Nr fruit, but did not change in the rin fruit. PE 2 was purified to homogeneity, judged by electrophoresis in dodecyl sulphate‐polyacrylamide gels.
The sorghum embryo in relation to the hydrolysis of the endosperm during germination and seedling growth
Authors: Aisien Anthony O. , Palmer Godfrey H.
Published: November 2006

Time‐course changes in the structural and physiological properties of sorghum grain embryo have been investigated in relation to the hydrolysis of the endosperm during germination and seedling growth. Histochemical analysis showed that the reserve food materials of the scutellum tissue were metabolised rapidly during germination and seedling growth. Light microscope analysis of structural changes showed that scutellar epithelial cell elongation was associated with endosperm reserve mobilisation. Electron microscope studies verified preliminary histochemical and light microscope findings and showed that extensive metabolism of subcellular storage materials occurred during early germination and seedling growth. Physiological evidence indicated that both sorghum embryo and endosperm were insensitive to the gibberellic acid, GA3. Other hormones such as indole‐3‐acetic acid and kinetin also failed to induce α‐amylase production. This suggests that the hormonal response of the aleurone of sorghum is different from that of barley aleurone. Dissection of sorghum showed that the whole body of the scutellum was capable of producing α‐amylase.
The effect of saponification, reduction and mild acid hydrolysis on the cell walls and cellulase‐treated cell walls of Lolium perenne
Authors: Tanner Guy R. , Morrison Ian M.
Published: November 2006

Cell wall material from the mature stems of perennial ryegrass (Lolium perenne) was hydrolysed with a commercial cellulase preparation. The residual insoluble material was fractionated by treatment with sodium hydroxide, sodium borohydride and mild trifluoroacetic acid and the carbohydrate and phenolic composition of the resultant fractions were compared with those of the original cell wall material. The susceptibility of the cell wall components to solubilisation by these treatments was found to depend more on their association with each other than on their intrinsic properties. These observations are discussed in relation to the concept of the secondary cell walls of plants as networks of cellulose microfibrils embedded in a ligno‐hemicellulose matrix.
A rapid screening method for determining the digestibility of kale using near infrared reflectance
Authors: Allison Michael J.
Published: November 2006

A Neotec Scanning Infrared Analyser was used to generate predictive equations for the rapid estimation of kale digestibility. The most successful of these equations gave estimates of digestibility of samples in a calibration population that correlated highly (r=0.95) with the manual estimates. When this method was applied to additional kale samples, not included in the calibration set, it was again successful in screening for high digestibility, despite lower correlation coefficients and increases in standard errors as compared to the equivalent results for the calibration set. Absorption peaks in the spectral scans of cell wall components were compared with the wavelengths used in the best prediction equation in an attempt to gain a clearer understanding of the factor or factors that limit kale digestibility.
An appraisal of currently used soil tests for available copper with reference to deficiencies in English soils
Authors: Tills Alison R. , Alloway Brian J.
Published: November 2006

Eight soil tests for plant‐available copper were used on twenty English soils of moderate to low copper status. The ability of these tests to predict plant copper uptake, tested in a pot trial, was compared using multiple regression analysis including other soil factors such as pH, organic matter and clay content.

The EDTA soil test was found to give the best prediction of plant uptake from a regression equation including EDTA extractable soil copper, pH, free Mn and Fe oxide, clay and organic matter content.
Peroxidase, catalase and palmitoyl‐CoA hydrolase activity in blanched carrot cubes after storage at −20°C
Authors: Baardseth Pernille , Slinde Erik
Published: November 2006

The effect of storage at − 20°C was studied on carrot cubes which had been blanched at 50°, 60°, 70° and 80°C for 2, 5, 10 and 20 min. A sample of unblanched carrot cube was used as reference. Results from sensory methods were compared with the activity of the three enzymes, palmitoyl‐CoA hydrolase, catalase and peroxidase. Good quality retention was obtained when palmitoyl‐CoA hydrolase was no longer present, while activity of catalase (9%) and peroxidase (6%) remained.
Studies on the palmitoyl‐CoA hydrolase activity in carrot
Authors: Baardseth Pernille , Slinde Erik
Published: November 2006

Carrot homogenate contains a palmitoyl‐CoA hydrolase. The enzyme was detected by spectrophotometric and radiochemical methods. The activation energy (Ea) for the reaction was determined to be 16700±2000 cal mol−1 with a Q10 of 1.8. The rate of reaction reaches its maximum at 45°C and ceases completely at 55°C. The inactivation energy was found to be 67000±11000 cal mol−1. A purification factor of 60 was obtained when polyvinylpyrolidone, polyethylene glycol, dithiothreitol and glycerol were used as stabilising agents, and the purification of palmitoyl‐CoA hydrolase was carried out without delay. The method used successively, polyethylene glycol fractionation and DEAE‐cellulose, hydroxylapatite and Ultrogel AcA 34 chromatography. Palmitoyl‐CoA hydrolase has a molecular weight of 42000 daltons and a pI of 4.6. The role of this enzyme in the development of off‐flavour in carrot has been discussed.
Measurement of levels of bread improvers in concentrates by means of near infrared reflectance spectroscopy
Authors: Osborne Brian G.
Published: November 2006

The simultaneous analysis of ascorbic acid, azodicarbonamide and L‐cysteine in bread improver mix concentrates at levels of 0–10% in a starch diluent has been achieved. The use of near infrared reflectance spectroscopy enabled the measurements to be obtained in less than one minute with accuracies of about ± 1% at the 95% confidence interval.