bluuebunny/crossref_metadata_2025 huggingface dataset:
Storage deterioration in Central African tea: The effect of some production variables on theaflavin degradation
Authors: Cloughley John B.
Published: October 2006

Different tea clones varied markedly in both rate and extent of theaflavin (TF) loss during storage. Teas manufactured and stored during the hot and humid main production season deteriorated more rapidly with respect to TF content than those produced and stored during the milder conditions of the off season. It was also found that introducing variations into each phase of manufacture resulted in altering the storage behaviour of teas.
Determination of organic acids and sugars in loquat (Eriobotrya japonica Lindl.) by high‐pressure liquid chromatography
Authors: Shaw Philip E. , Wilson Charles W.
Published: October 2006

The major sugars and organic acids in three cultivars of loquat‐Tanaka, Thales and Christmas‐were quantified by high‐pressure liquid chromatography. The cultivars differed in sugar and acid contents and changes in these contents during ripening were determined for one cultivar. Trace quantities of several unknown acids that had not been reported earlier in loquat were observed in the Tanaka sample. Major B‐vitamins, thiamin, riboflavin and niacin, were quantified for one cultivar and were at the approximate levels found in other fruit.
Studies on the production of saccharinic acids by the alkaline treatment of young grass and their effectiveness as substrates for mixed rumen microorganisms in vitro
Authors: Williams Alan G. , Morrison Ian M.
Published: October 2006

The treatment of timothy grass stem tissue with sodium hydroxide in the presence of air resulted in a rapid fall in the amount of soluble D‐glucose and D‐fructose in the plant material. Lactic acid and other degradation products with retention times on gas‐liquid chromatography similar to saccharinic acids were formed. The calcium salt of α‐D‐glucoisosaccharinic acid, although taken up by the rumen bacteria and holotrich protozoa studied, was not readily metabolised as assessed by gas, volatile fatty acid and lactate production and incorporation studies. Using the same criteria, the calcium salts of α,β‐D‐glucometasaccharinic acids were not assimilated by either of the microbial cell preparations isolated from sheep receiving a diet of hay and sugar‐beet pulp. The uptake of D‐glucose by the bacterial and protozoal preparations was affected in incubations in vitro containing increased concentrations of the α‐D‐isosaccharinic acid and D,L‐lactic acid, respectively.
Quality characterisation of strawberries for industrial jam production
Authors: Skrede Grete
Published: October 2006

Six strawberry varieties were evaluated as raw materials for industrial jam production. The investigation involved chemical, physical and sensory analyses of fresh and frozen/thawed fruits as well as jam at the time of production and after 3 months of storage. Among the varieties studied, Jonsok and Senga Sengana appeared most suitable, followed by Bounty and Tenira. The other varieties, Fructana and Totem, were less satisfactory for this purpose. Based on linear correlation analyses (P<0.05), the relevance of various parameters in evaluating fruits intended for jam production is discussed. The results disclosed pH, titratable acids and sugars of fresh fruits to be less important to jam quality. High contents of soluble solids and ascorbic acid were related to undesirable flavour properties of jams. Further, high levels of ascorbic acid adversely affected colour stability. Colour degradation in jams was parallel to flavour deterioration. It is concluded that the main emphasis should be given to characteristics of the final products rather than to characteristics of the fresh fruits.
Comparison of methods for the determination of free and bound sulphur dioxide in stored British fresh sausage
Authors: Banks Jeffrey G. , Board Ron G.
Published: October 2006

A modified spectrophotometric assay for free sulphur dioxide (SO2) in sausage recovered significantly more SO2 than an electrometric ion‐selective probe method. The former was less variable than the latter. For total SO2 estimation, the spectrophotometric method gave results which were not significantly different from the Monier‐Williams distillation technique and correlation was excellent. An ion‐selective probe method showed poor correlation with, and gave significantly different results from, the Monier‐Williams technique. By use of the spectrophotometric assay, the rate of loss of free and total SO2 from sausage was found to be related directly to temperature; high storage temperatures favoured rapid loss of SO2. Significantly more free SO2 was lost from the surface than the centre of sausage and the sampling site had no significant effect on the rate or extent of total SO2 loss.
Attempted isolation of fluorescent ageing pigments from apple fruits
Authors: Knee Michael
Published: October 2006

The suitability of the lipofuscin assay for lipid peroxidation products in apple fruit has been investigated. Material with similar fluorescent properties to lipofuscin was extracted from apple. However, this fluorescence could be explained by the presence of cinnamoyl compounds and carotenoids in the extracts.
Reduction of bitterness and acidity in grapefruit juice by adsorptive processes
Authors: Johnson Robert L. , Chandler Bruce V.
Published: October 2006

By choosing an appropriate adsorbent, the bitter principles (naringin and limonin) and titratable acids could be removed from grapefruit juice in varying combinations. For example, Amberlite XAD‐7 removed about 63% naringin, 85% limonin and 3% titratable acids and Deacidite‐FFIP removed about 20% naringin, 8% limonin and 23% titratable acids when contacted for 1 h with grapefruit juice at the rate of 20 g (dry wt) of adsorbent per litre of juice. Such treatments, applied consecutively, would eliminate excessive bitterness and acidity from juices containing up to 2 g naringin and 36 mg limonin litre−1 and with a total soluble solids:titratable acid ratio of < 6. The adsorbents are readily available, may be used as supplied and can be reactivated simply and economically; some of them have already been approved for use with foods, and such approval seems possible for the others.
Effects of age and variety on nitrate reductase and nitrogen fractions in potato plants
Authors: Kapoor Amin C. , Li Paul H.
Published: October 2006

The effects of plant age and variety on the level of nitrate reductase activity in three varieties of Solanum tuberosum (Kennebec, Norchip and Early Ohio) have been studied by assaying nitrate reductase at different intervals during growth and development. Nitrate reductase appears to be localised in leaves and young stems. Negligible nitrate reductase activity was recorded in roots and tubers. The varieties differed significantly in nitrate reductase activity and the tuber protein nitrogen content paralleled the level of activity in leaves. The levels of nitrate reductase activities in leaves were also highly positively correlated with quantities of leaf inorganic nitrogen, protein and free amino acids. The activity began to decline at about 50 days after emergence, and this may be a useful indicator of when to apply nitrogen fertiliser so as to increase tuber protein content.
Effect of withering on the polyphenol oxidase level in the tea leaf
Authors: Ullah Mohammed R. , Roy Prafulla C.
Published: October 2006

The level of polyphenol oxidase in tea leaf (Camellia sinensis) decreased on partial desiccation of the leaf during the withering process of black tea manufacture. However, sufficient activity remained, even after withering, to oxidise the available substrate in the leaf. The loss in activity due to desiccation was restored on rehydration.
The conditioning of wheat. The influence of varying levels of water addition to UK wheats on flour extraction rate, moisture and colour
Authors: Hook Simon C. W. , Bone Geoffrey T. , Fearn Thomas
Published: October 2006

An investigation of the effect of varying levels of water addition on milling parameters of four currently used UK wheats has shown that there is no significant variation of these parameters for the lying times studied. The wheats have been milled 1.5, 3, 7 and 24 h after water addition; two wheat moisture levels have been investigated and, in addition, an assessment of the moisture distribution within the wheats has been made for each of the lying times studied. Flour extraction rates remained almost constant throughout the lying times range for each wheat moisture level. Flour moisture contents increased with lying time up to 7 h and then remained constant. Hence, it has been shown for a number of typical UK wheats that short lying times for conditioning are quite feasible.
The conditioning of wheat. An investigation into the conditioning requirements of Canadian western red spring no. 1
Authors: Hook Simon C. W. , Bone Geoffrey T. , Fearn Thomas
Published: October 2006

Canadian Western Red Springs (CWRS) No. 1 wheat has been conditioned to 16 and 17% moisture content by 2 and 4% water additions in each case. Lying times in the range 4–48 h before milling have been investigated. The milling performance of the conditioned wheat has been assessed in terms of extraction rate, colour and flour moisture content. Lying times in excess of 12 h were found to have no influence on extraction rate, colour and flour moisture content. For lying times less than 12 h the extraction rate was affected by the level of added water. When CWRS No. 1 wheat was milled at moisture contents in the range 14–18% using a fixed lying time, extraction rate, flour colour and ash fell with increasing wheat moisture content while flour moisture content increased.
The effect of sunflower oil on the fatty acid composition of the milk of Cows fed either a fat‐depressing diet or grass silage
Authors: Clapperton J. L.
Published: October 2006

Two experiments have been carried out in which different forms of sunflower oil were added to the diet of Ayrshire heifers. In experiment 1, the animals were given a fat‐depressing diet of dried, ground grass cubes and flaked maize. When either free sunflower oil or milled, unextracted sunflower seeds were added to this diet, the yield of milk fat and of all fatty acids up to 16:1 was decreased and the yield of all 18‐carbon fatty acids was slightly increased. When the sunflower oil was protected by encapsulation in formaldehyde‐treated casein, the yield of milk fat was increased, that of the fatty acids up to 16:1 was decreased and that of all the 18‐carbon fatty acids, and in particular, of the polyunsaturated fatty acids was increased. In experiment 2, the animals were given a basal diet of grass silage and concentrates to which increasing amounts of protected sunflower oil were added. This tended to increase the yield of milk fat and to reduce that of the fatty acids up to 16:1. The yield of all the 18‐carbon fatty acids increased and, in particular, that of the polyunsaturated fatty acids increased progressively as more protected oil was added. It is concluded that it should be possible to produce a milk with any desired proportion of polyunsaturated fatty acids by adding a predetermined amount of protected oil to the diet of the cow.
Changes in sensory properties of sausages when small amounts of blood replace meat
Authors: Slinde Erik , Martens Magni
Published: October 2006

Changes in the sensory properties (colour, flavour and texture) of Frankfurter‐type sausages have been evaluated when small amounts of blood, 0–50 g kg−1 of the total recipe, are substituted for meat. Smaller amounts of blood (˜ 2%) improve the total impression of colour and meat taste when compared with a reference sample (no blood added). A core temperature of 78°C for 5 min was used to denature haemoglobin completely, otherwise off‐flavour (blood‐taste) and colour problems prevail. When adding blood a dark colour and off‐flavour seem to be the most critical parameters with respect to acceptability.
Distribution of radioactive 32P in buffaloes' skimmed milk as affected by processing
Authors: Sindhu Jagveer S. , Roy Nirendra K.
Published: October 2006

The distribution of phosphorus between the soluble and colloidal phases in buffaloes' skimmed milk, and the effects of five heat treatments on it, was determined by the rennet coagulation technique. The original P in milk and radioactive 32P incorporated into milk, both in vitro and in vivo, were estimated for total and soluble phases by chemical and radioassay methods. The heat treatments consisted of pasteurisation (15 s at 71.8°C), pre‐warming (5 min at 96°C), sterilisation (15 min at 121.5°C), and cooling for 24 h at 4–6 and 0°C. When 32P was added in vitro about 60% remained in the soluble phase; if incorporated in vivo, about 39% was in the soluble phase, while the level of the original P was about 38%. Pasteurisation, pre‐warming and sterilisation progressively decreased the soluble in‐vitro incorporated 32P to about 58, 48 and 34%, respectively. Cooling at 4–6 and 0°C altered the soluble in‐vitro incorporated 32P to approximately 53 and 57%, respectively, from about 64% in the raw milk. On the other hand, changes in partitioning of either in‐vivo incorporated 32P or original P due to any of the five processing treatments were small, non‐uniform and not statistically significant.
Establishment and growth of different plantain propagation materials
Authors: Obiefuna Julius C. , Ndubizu O. C. Thomas
Published: October 2006

Five different types of plantain (Musa spp. AAB) planting materials—early sword suckers, late sword suckers, peepers, maidens and bits—were established at the beginning of the rainy season and grown for 9 months, over the first subsequent dry season. Their pre‐floral vegetative growth during the 9 month period was then studied. The late sword suckers made most growth and had the best survival rate over the dry season followed by maidens and early sword suckers. Peepers and bits were the least successful materials and are not recommended as propagation materials in areas with long and severe dry seasons.
The association of saturated and unsaturated triglycerides and oleic acid with wheat flour components during dough making
Authors: Warwick Michael J. , Shearer George
Published: October 2006

The association of lipids with other flour components after dough making has been examined by aqueous fractionation of flour prior to the extraction of lipids. Glycerol tripalmitate has been shown to be associated with acetic‐acid‐insoluble protein while glycerol trioleate associates with the glutenin of acetic‐acid‐soluble protein. Oleic acid divides fairly evenly between these fractions. Changes in lipid and protein distribution in some fractions are associated with the addition of oleic acid to the dough. Some of these changes are at least partially reversed by increasing the triglyceride content of the dough.
The distribution of acyl lipids and tocopherols in flours millstreams
Authors: Morrison William R. , Coventry Anne M. , Barnes Peter J.
Published: October 2006

Kernels from a mixed hard wheat grist were dissected into germ, bran (pericarp, testa and aleurone), and starchy endosperm for direct analysis of tocopherols in lipid extracts by high‐performance liquid chromatography. α‐ and β‐tocopherols were almost exclusively in the germ, α‐tocotrienol was mostly in the bran, and β‐tocotrienol was equally distributed between the bran and the starchy endosperm. Acyl lipids and tocopherols were quantified in 23 millstreams obtained from this grist. Components related to germ and bran (triglyceride, diacylphospholipids, ã‐ and β‐tocopherols) and testa (flour colour) showed the highest coefficients of variation whereas endosperm components (glycolipids, N‐acylphospholipids and β‐T‐3) showed exceptionally low variation. The quantities of marker tocopherols in the streams were used to calculate the composition of the lipid transferred to the flour from germ and aleurone, and to predict the composition of the basic endosperm, free of aleurone and germ lipids. Low proportions of diacylphospholipids in the lipid transferred to high‐grade millstreams indicated the transfer of spherosome lipid. The low‐grade streams exhibited high proportions of phospholipids suggesting additional transfer of germ tissue and aleurone tissue containing membrane lipids. Protein and ash contents of the transferred fraction confirmed that a substantial proportion of the transferred lipid was probably accompanied by protein bodies or by tissue fragments. It is estimated that aleurone contributed less than one‐quarter of the transferred lipid in any stream. Hexane‐extractable free lipids in four representative streams consisted of almost all the non‐polar lipids, 40–67% of the glycolipids, 47–54% of the diacylphospholipids and 30–60% of the lysophospholipids.
The determination of olaquindox in pig feeds by high‐performance liquid chromatography
Authors: Thente Karin , Andersson Bernt
Published: October 2006

A simple, rapid method, based on high performance liquid chromatography, h.p.l.c., is described for the determination of olaquindox in pig feeds. The drug is extracted from the feed by use of a methanol‐water mixture, an aliquot is injected on to the h.p.l.c.‐column and quantified by u.v.‐detection. The method has been tested on feeds and premixes containing olaquindox between 1–400 mg kg−1.
Effects of husbandry treatments on nitrogen concentration of grain and related yields in winter‐wheat experiments made in South‐East England
Authors: Benzian Blanche , Lane Peter
Published: October 2006

Experiments by Rothamsted staff over 20 years show that N (protein) concentration in wheat grain is influenced considerably by several husbandry treatments other than total fertiliser N. Even small differences can be of practical importance if values lie close to the minimum standard for bread wheat. In 15 experiments which tested timing of fertiliser N, an extra 60 kg ha−1 would have been needed in autumn to increase grain‐N concentration by 0.1% on average, but only 43 kg in early and 30 kg in late spring. The response to autumn N was similar in a ley‐arable rotation experiment Fertiliser N applied to a previous potato crop gave a grain‐N% increase equivalent to a quarter of the fresh application on a silty clay loam soil but none on a sandy loam. Cumulative annual dressings of farmyard manure benefited grain‐N% as did residues from FYM applied to a previous potato crop, which gave increases equivalent to those from 16 kg ha−1 of fresh fertiliser N. In ley‐arable rotation experiments, wheat after arable cropping did not reach bread‐quality standard with the largest amount of fertiliser N (150 kg ha−1), but after lucerne N% values exceeded the threshold value of 2.14% N with all rates. Benefits from lucerne and a grass‐clover ley were still considerable when wheat was grown as a second test crop after potatoes. Yield responses to these husbandry treatments tended to be small and positive, except that in the presence of larger dosager of fertiliser N farmyard manure sometimes caused a depression.
Water uptake by cocoa seeds during fermentation‐like incubation
Authors: Biehl Böle , Quesnel Victor C. , Passern Detlef , Sagemann Wilfried
Published: October 2006

During anaerobic incubation in citric acid/NaOH (35 mmol; pH 5.5) at 40°C the fresh weight of ripe cocoa seeds (without testae) increases considerably (17–27% within 40 h) by water absorption. This is similar to water uptake during germination at 25–30°C. At 50°C in the same medium, weight increase (3.5–7.3% within 40 h) as well as net water uptake is low. Subcellular compartmentation is destroyed at 50 but not at 40°C. Since water uptake is greatly reduced or is impaired at 40°C in the presence of osmotically active substances like sucrose, it is concluded that intact vacuoles in the cotyledons are responsible for high water absorption. In the presence of acetic acid (200 mmol; 50°C) weight increase is low but loss of dry matter is increased by exudation. These findings are discussed with respect to protein vacuole swelling and proteolysis during fermentation and germination.
Plant growth inhibitory activity of extracts of raw and treated pig slurry
Authors: Ramirez Maureen E. A. , Garraway James L.
Published: October 2006

Strong acid extracts from raw and treated pig slurries were highly inhibitory to the germination and root growth of barley and wheat. While the activity of the extracts reflected the level of phenolic acids therein, the possibility of other substances contributing to this activity cannot be excluded. Tests with pure compounds showed that certain individual phenolic acids identified in pig slurries inhibited germination and root growth but at higher concentrations than previously reported. Of the treatment systems studied, aeration of pig slurry was the most effective in removing the inhibitory activity associated with extracts.
Proteolysis during fermentation‐like incubation of cocoa seeds
Authors: Biehl Bole , Passern Detlef
Published: October 2006

Proteolysis in cocoa seeds was studied by fermentation‐like anaerobic incubation to determine whether post‐mortem proteolysis depends only on temperature and acidity. In acetone dry powder incubation, autolytic release of α‐amino nitrogen is optimal at pH 4.0‐4.5 and is higher at 55°C than at 45°C. Proteolysis increases with acidification. However, in seed and seed fragment incubation, acetic acid is more effective than citric acid under similar conditions. Further, a first incubation at a low temperature (40°C) in contrast to a high temperature (50°C) favours post‐mortem proteolysis during a subsequent incubation of cotyledon tissue at 50°C in an acetic solution, whereas it does not with cotyledon dry powder in the same solution. This effect of pre‐incubation temperature in seeds is diminished in the presence of a high concentration of acetic acid. It does not depend on microorganisms, on exudation or on interaction of proteins and polyhydroxyphenols. Since increased proteolysis after incubation at 40°C correlates with structural changes in protein vacuoles and with water uptake by the intact seeds, a causal relationship is indicated.
Degradation of cell walls of forages by sequential treatment with sodium hydroxide and a commercial cellulase preparation
Authors: Hartley Roy D.
Published: October 2006

Cell walls of barley straw (whole sample and stem), Italian ryegrass (shoot) and lucerne (mature stem) were treated sequentially with NaOH followed by a commercial ‘cellulase’ preparation and, in other experiments, with the cellulase followed by the alkali. The phenolic compounds released by NaOH were determined and related to increases in the degradability of the walls as measured with cellulase. Two sequential treatments of the cell walls of barley straw increased degradability from 11% on treatment with cellulase alone to 87%, compared with increases from 72 to 99% and from 19 to 54% for the ryegrass and lucerne walls respectively. The first alkali treatment released ferulic and p‐coumaric acids from the walls of barley and ryegrass together with other u.v. absorbing compounds, whereas the compounds released by the second alkali treatment did not include these two acids. The treatment with alkali did not release either ferulic acid or p‐coumaric acid from the walls of lucerne and the amounts of other u.v. absorbing compounds that were released were much smaller.
A study of the variability of the endogenous energy output by adult roosters and a determination of the available energy of nine different feedstuffs
Authors: Campbell L. D. , Jacobsen I. , Eggum B. O. , Just A.
Published: October 2006

The variability of energy excretion by adult roosters starved for 24 h or force‐fedvarying levels of dextrose following a 24‐h fast was studied in three separate balance trials. A fourth balance trial was conducted to determine the available energy content of several feedstuffs. Dry matter and energy excretion were measured in the first three trials and available energy was determined as true metabolisable energy (TME) for adult roosters and as apparent metabolisable energy (AME) corrected to zero nitrogen retention for growing rats and pigs in the fourth trial. A significant (p < 0.05) positive correlation (r=0.81) between body weight (range 1.9–2.8 kg) of roosters and energy excretion was observed. Energy excretion by roosters tended to vary with the level of dextrose force‐fed and the calculation of TME of dextrose produced values equal to its gross energy at high (50–60 g) levels of intake. The TME content of nine feedstuffs varying in chemical composition are given and compared with AME values determined with rats and pigs.
The sodium, potassium and chloride contents of some feedingstuffs used in British poultry diets
Authors: Bain Henry , Mitchell George G. , Dewar William A.
Published: October 2006

The sodium, potassium and chloride contents of feedingstuffs used in practical and purified diets are reported. The sodium contents of some cereals and cereal by products are considerably lower than those in the literature.
Relationships between labile‐P, NAHCO3‐soluble P, and mobilisation of non‐labile P in soils treated with inorganic phosphate fertilisers and organic manures
Authors: Brookes Philip C. , Mattingly Geoffrey E. G. , White Rodger P. , Mitchell J. Douglas D.
Published: October 2006

Weighted‐mean L‐values and uptakes of P by plants were determined using ryegrass grown in a controlled environment on soils obtained from long‐term field experiments at Rothamsted (Batcombe and Winchester soil series), Woburn (Stackyard and Cottenham series) and Saxmundham (Beccles series) given different organic and inorganic manurial treatments. Linear regression analysis showed that, under the experimental conditions used, (small soil volume, weekly additions of all nutrients other than P) initial soil NaHCO3‐soluble P accounted for more than 95% of the variance of plant‐P uptake and weighted‐mean L‐values. The relationships between NaHCO3‐soluble P, plant‐P uptakes and weighted‐mean L‐values (labile P) were all independent of soil type and form of P fertiliser applied. In most soils, L‐values increased with increasing cut number, and the rate of increase was linearly related to initial soil NaHCO3‐soluble P, suggesting that NaHCO3‐P measurements may provide useful information on the availability of initially non‐isotopically exchangeable soil‐P reserves. The plants removed about 68% more P from the soils than was measured as initially NaHCO3‐soluble and about one‐half the labile soil‐P. Labile soil‐P was 3.5 times greater than initial NaHCO3‐soluble P. The initial soil NaHCO3‐soluble P required to provide at least 95% of maximum yield increased with increasing cut number (from 37 mg P kg−1 soil at cut 1 to 160 mg P kg−1 soil at cut 4), probably because the NaHCO3‐P pool was replenished more slowly than P was removed by the plants.
Response of grassland to the application of sulphur at two sites in north‐east scotland
Authors: Scott Norman M. , Watson Marion E. , Caldwell Kynoch S. , Inkson Robert H. E.
Published: October 2006

The effect of sulphur fertilisation on yield and herbage composition was investigated in two successive years at two grassland sites, one with ryegrass and one with ryegrass/ clover, where the available sulphur in the soil was less than 10 mg kg−1. When supplies of N, P and K were not limiting, herbage yields increased with added sulphur at both sites, particularly at the second and third cuts and in the second year. Sulphur additions also increased the concentrations of total S and SO4−2−S in the crop, and reduced the N:S ratio. The figures for these parameters in herbage from control plots confirmed that low yields in the presence of normal nitrogen fertilisation were probably caused by sulphur deficiency.
Solubilisation and characterisation of wheat gluten proteins: Correlations between the amount of aggregated proteins and baking quality
Authors: Field J. Michael , Shewry Peter R. , Miflin Benjamin J.
Published: October 2006

A comparison was made of the effectiveness of various solvents in extracting protein from wheat gluten. The best proved to be 0.055m cetyltrimethyl ammonium bromide‐6m urea‐0.01m acetic acid. When extracts were separated on columns of controlledpore glass, with a nominal exclusion limit of 1.2 × 106 daltons for molecules in the extended form, two peaks were obtained termed F1 and F2. F1 was excluded from the column and contained material which was stable in the absence of reducing agent but was markedly reduced in size in the presence of 2‐mercaptoethanol. SDS‐PAGE showed that F1 was enriched in high molecular weight polypeptides (about 100 000 daltons) and also contained polypeptides with molecular weights in the range 30 000–45 000. F2 consisted almost entirely of polypeptides with molecular weights of less than 50 000. The ratio of F1 :F2 in different varieties varied from 0.1 to 0.58 and this variation was correlated with the NIAB potential breadmaking quality score. However, there did not appear to be any difference between the total amounts of high molecular weight polypeptides in a poor and a good breadmaking variety.
Folate content of various Nigerian foods
Authors: Huq Razia S. , Abalaka Joseph A. , Stafford Winnie L.
Published: October 2006

Various raw and processed food items commonly consumed in three selected communities around Zaria, in northern Nigeria, have been examined for their folate contents using Lactobacillus casei. The folate levels of most of the foodstuffs were low. The estimated folate intake by individuals consuming these foodstuffs, calculated on a normal three‐meals‐a‐day basis, was less than recommended daily intake levels.
Autolysis of mimosine to 3‐hydroxy‐4‐1(h)pyridone in green tissues of Leucaena leucocephala
Authors: Lowry J. Brian , Maryanto  , Tangendjaja Budi
Published: October 2006

Enzymes present in Leucaena leucocephala can rapidly degrade mimosine to 3‐hydroxy‐4‐1(H)pyridone (DHP). At 45°C, half of the mimosine in macerated leaves is degraded in 4 min. This activity is confined to leaflets and lamina of the young pod, although mimosine also occurs in other tissues. Simple processing can give a leaf meal largely free from minosine, or can break down most of the mimosine in pods used as human food; the problem then becomes that of the toxicity of DHP. Leaf autolysis can be utilised to prepare DHP.
Increased drying rate of cut lucerne (alfalfa) with alkali metal carbonate solutions
Authors: Johnson Timothy R. , Thomas J. William
Published: October 2006

Spray treatment of cut lucerne (alfalfa) with 0.2m solutions containing carbonates of the alkali metal group increased mean dry matter content and drying rates above an untreated control. Dry matter content of lucerne sprayed with carbonates of caesium, rubidium or potassium was greater than that of lucerne treated with solutions containing sodium carbonate, lithium carbonate or left as untreated control, throughout the drying period. Drying rates at any given water content between 2.5 and 0.5 were also greatest for lucerne treated with solutions containing caesium, rubidium or potassium carbonate. Mean drying rate of lucerne sprayed with alkali metals was positively related to their ionic radius and increased from lithium to caesium.
Assessment of nitrogen status of soils for cereal crops: Use of plant and soil analysis to diagnose nitrogen status of spring barley
Authors: O'Neill Eileen J. , Batey Thomas , Cresser Malcolm S.
Published: October 2006

The results of field experiments with spring barley at two locations in 1978 and 1979 were used to evaluate early season measurement of soil mineral N, plant N and chlorophyll, and nitrogen stress as indicators of straw and grain yields and N uptake at maturity. A new definition of N stress based upon rates of N uptake is proposed. Plant N and chlorophyll contents early in the season were positively related (P< 0.001) to final N uptake. Early season N stress (based on growth rate) was negatively related (mainly P< 0.001) to grain yield and, less strongly, to N uptake. There appeared to be some advantage in using rate of N uptake rather than growth rate to define N stress for the purpose of predicting crop final N uptake.
An enzyme‐linked immunosorbent assay for total glycoalkaloids in potato tubers
Authors: Morgan Michael R. A. , McNerney Ruth , Matthew Jennifer A. , Coxon David T. , Chan Henry W.‐S.
Published: October 2006

An antiserum raised against a solanine‐bovine serum albumin conjugate has been characterised and shown to be specific for the glycoalkaloids found in commercially available potatoes. The antiserum has been employed at high dilution in an enzyme‐linked immunosorbent assay (ELISA) for the glycoalkaloids. The assay is sensitive and precise and has many advantages over alternative procedures currently employed. Potato sample preparation is minimal and no recovery factors are required.
Improvement of nutritional value of common beans (Phaseolus vulgaris) by autoclaving or extraction
Authors: Wyckoff Sheri , Vohra Pran , Kratzer F. H.
Published: October 2006

Larval weight of Tribolium castaneum was used to evaluate six varieties of common beans (Phaseolus vulgaris). Beans incorporated into test diets were raw, autoclaved, or extracted with either water or 80% methanol. All treatments improved the nutritional quality of beans when compared to raw beans. The bean extracts were growth depressing. In another study heating of the freeze‐dried water extract of black beans improved its nutritive value but not of the methanol extract. Tribolium castaneum larvae may be used to evaluate the nutritional quality of Phaseolus vulgaris and different bean treatments.
A survey of styrene monomer levels in foods and plastic packaging by coupled mass spectrometry—automatic headspace gas chromatography
Authors: Gilbert John , Startin James R.
Published: October 2006

An extensive UK survey of styrene monomer levels in styrene based plastic packaging materials and their contained foods (133 samples) has been carried out, examining a wide range of retail foods of different brand names and including yogurts, creams, salads, coleslaws, soft cheeses, margarines, hot and cold beverages from dispensing machines, spreads, fresh and cooked meats, candied fruits, fresh strawberries, and take‐away ‘fast’ foods. Analysis by headspace gas chromatography of styrene levels in the plastic containers showed levels of monomer ranging from 16 to 1300 mg kg−1 although the majority of containers (73%) had styrene levels in the range 100–500 mg kg−1 and only five plastic tubs had levels exceeding 1000 mg kg−1. Analysis of the food contents of the plastic containers by automated headspace gas chromatography with single ion monitoring mass spectrometric detection showed levels of the monomer ranging from < 1 μg kg−1 to 200 μg kg−1, although the majority of foods (77%) had styrene levels below 10 μg kg−1, and 26% of the total number analysed had levels below 1 μg kg−1.
Protein degradation in the rumen of sheep and cattle
Authors: Siddons Rodney C. , Paradine John
Published: October 2006

Sheep and steers were given, at a maintenance level of feeding, four diets consisting of either poor quality dried grass, good quality dried grass or separate mixtures (63:35) of each of the dried grasses and barley. Ammonia and total N concentrations in rumen liquor were significantly higher in sheep than in steers whereas total volatile fatty acid concentration was significantly lower and protein N concentration, pH and rumen fluid dilution rate did not differ significantly between species. For all rumen measurements, except total volatile fatty acid concentration, there were significant differences between diets with the dietary responses being similar in both species. Protein degrading activity in the rumen was measured in vitro with casein as the substrate and in situ by measuring N disappearance when soyabean meal, cotton seed meal, groundnut meal, meat and bone meal, fish meal and dried grass were incubated in polyester bags in the rumen. Casein degrading activity of rumen liquor did not differ significantly between species, whereas rumen in‐situ degradation of all feedstuffs, except fish meal, was significantly higher in sheep. In both species, ruminal casein degrading activity was higher when the good quality forage was given than when the poor quality forage was given and also increased when part of each forage was replaced by barley. In contrast, rumen in‐situ degradability of feedstuffs did not differ when the two all‐forage diets were given and the inclusion of barley in the diet reduced the rate of degradation. In both species and with all diets the rumen in‐situ degradability ranking of the feedstuffs was similar.
Studies on keeping quality of ghari prepared from cow and buffalo milk
Authors: Khader Vijaya , Bhavana Desai B.
Published: October 2006

Ghari prepared from cow and buffalo milk stored at room temperature was found to be acceptable for 2 weeks, whereas refrigerated ghari remained acceptable for 4 weeks. Acidity increased and iodine value decreased on storage but no significant difference was observed between the temperature treatments. Saponification value remained constant throughout the study. The increase in peroxide value was directly proportional to storage time and temperature. Cow ghari had a higher unsaturated fatty acids content but it declined as the storage time increased. No adverse changes were observed in the fatty acids in ghari samples stored at two different temperatures for a period of 4 weeks.
The examination of the headspace volatiles of watercress
Authors: Spence Rose‐Marie M. , Tucknott Owen G.
Published: October 2006

Watercress volatiles were collected by adsorption on Porapak Q and solvent elution to obtain samples representative of the intact plant material with minimum glucosnolate degradation. Samples taken after 2 and 7 days trapping as the watercress deteriorated were compared. Several compounds which contribute to the aroma of watercress were identified by gas chromatographic and mass spectrometric analysis and odour evaluation of the gas chromatographic effluent.
Protein extraction from pasture: Effect of crop species, regrowth age and season on the quality of the extracted protein
Authors: Donnelly Paul E. , McDonald Rod M. , Rattray Peter V.
Published: October 2006

Leaf protein concentrates (LPC) were prepared from ryegrass (Lolium perenne), white clover (Trifolium repens), lucerne (Medicago sativa cv. Wairau), and from ryegrass/white clover dominant pasture, harvested after a range of regrowth intervals in spring, summer and autumn seasons. Protein quality was measured by rat growth (to give Relative Nutritive Value, RNV) and in‐vivo rat true digestibility. RNV for LPC prepared from all crops was about 50% of that for lactalbumin. Results were highest for lucerne and lowest for ryegrass and ryegrass/white clover. When LPC was supplemented with methionine, RNV improved to 80–90% of that for lactalbumin. Quality was highest and similar for white clover and lucerne and lowest and similar for ryegrass and ryegrass/white clover. The true digestibility of protein was highest for lucerne (82%) and lowest for ryegrass and ryegrass/white clover (70%). These variations may be related to the proportions of cytoplasmic and chloroplastic protein in the juice. There was no effect of season (autumn vs spring) or age of herbage at harvest (4, 6, or 8 weeks regrowth) on the quality of protein. Despite standardised procedures for harvesting, processing, and drying the LPC and for assessing protein quality, undefined factors caused variation in methionine‐supplemented protein quality.
Protein extraction from pasture: The nutritional availability of methionine, cystine and lysine in leaf protein concentrates
Authors: Donnelly Paul E. , Rattray Peter V.
Published: October 2006

Leaf protein concentrates (LPC) were prepared from ryegrass (Lolium perenne), white clover (Trifolium repens), mixed ryegrass/white clover and lucerne (Medicago sativa cv. Wairau). Total and nutritionally available levels of methionine and cystine, and nutritionally available levels of lysine were measured. Total and available methionine in LPC averaged 1.94 and 1.60 g 16 g−1 N respectively. The availability of methionine was increased (from 81% to 85%) when the herbage was treated with sodium metabisulphite before pulping. Total and available cystine in LPC averaged 0.96 and 0.26 g 16 g−1 N respectively; availability increased (from 27% to 73%) when herbage was treated with metabisulphite. Of the two sulphur amino acids, cystine undergoes the greatest nutritional damage during processing in the absence of reducing agent. Available lysine averaged 5.29 and 5.61 g 16 g−1 N for control and metabisulphitetreated LPC respectively. Improvements due to metabisulphite were small. Available lysine was higher in LPC from legume herbages (5.9 g 16 g−1 N) than from ryegrass and ryegrass/white clover herbage (5.0 g 16 g−1 N).
Cation exchange capacity and buffering capacity of neutral‐detergent fibres
Authors: McBurney Michael I. , van Soest Peter J. , Chase Larry E.
Published: October 2006

Dietary fibre buffers the gastrointestinal tract via the inherent buffering capacity of the specific fibre matrix, the quantity of cell wall ingested and the stimulatory effect of cell wall on rumination and/or salivation. The strong bonding of Cu2+ ions for carboxy groups permits their use in estimating the cation exchange capacity (CEC) of both pectinaceous materials and pectin‐free cell wall fractions. The CEC values observed emphasise the different cation exchange capacities of the various plant cell wall components. Cellulose has a relatively low exchange capacity while lignin and Maillard products have a much greater adsorption. Emphasis is placed on the difficulty in utilising gravimetric determinations to interpret physicochemical effects as well as the diversity of plant sources in terms of gastrointestinal buffering.
Polyphenoloxidase from DeChaunac grapes
Authors: Lee C. Y. , Smith N. L. , Pennesi A. P.
Published: October 2006

Polyphenoloxidase (PPO) from red grape cultivar, DeChaunac, grown in New York State was isolated and purified 17‐fold by using Phenyl Sepharose CL‐4B column. Disc gel electrophoresis revealed near homogeneity of three isoenzyme bands. The molecular weight of this enzyme ranged from 73 000 to 85 000. The temperature and pH optima of the purified enzyme were 20 °C and 6.0, respectively. Kinetic studies showed that the thermal inactivation of the PPO followed first‐order kinetics, with the activation energy, Ea = 52.39 Kcal mol−1. The substrate specificity showed a high degree of PPO activity toward o‐diphenolic compounds with the highest affinity toward caffeic acid among substrates studied. The apparent Km values for caffeic acid and 4‐methylcatechol as substrates for the Dechaunac PPO were 16 mmol and 25 mmol, respectively. The most potent inhibitors of the PPO were D.L‐dithiothreitol and sodium metasulphite at the concentration level of 0.5 mmol.
Location of sources of variation in forage digestibility
Authors: Moir Kenneth W.
Published: October 2006

Data from tables of composition of animal feedstuffs in which there were entries for digestibility (digestible dry matter or digestible organic matter) and cell wall were classified into different categories—grass or legume, stage of growth, leaf or stem, and forage species. No conclusions were drawn about legumes, because of insufficient data. After removing the effect of different categories, all the grass species behaved similarly with respect to digested cell walls, In contrast, within‐species variation in digested cell walls was large, as shown by the high residual standard deviation of ± 4.0 in a simple linear regression of in‐vivo digestibility on cell‐wall content. There was a small effect which was due to the lignin content of the cell wall, but the source of most of the variation was not located. While it remains undiscovered, there is a danger that experiments involving forage might merely be testing the effect of treatment on random variation in the digested cell wall.
Production and composition of microbial fat from Rhodotorula glutinis
Authors: Misra Suniti , Ghosh Amitabha , Dutta Jyotirmoy
Published: October 2006

The fatty acid, sterol and hydrocarbon compositions of oil produced by a new strain of Rhodotorula glutinis isolated from soil and grown on molasses, were determined. The major constituent fatty acids were: palmitic (37%) oleic (47%) and linoleic (8%). The major sterols were campesterol (42%) and stigmasterol (27%) and the major hydrocarbons were n‐C23 (37%), iso‐C29 (30%) and n‐C21 (19%). Minor constituents in each class of lipids were also detected and estimated. The oil produced was 54% on a dry weight basis. The fatty acid composition was found to be close to that of palm oil.
Major albumins of Pisum cotyledons
Authors: Schroeder Harmut E.
Published: October 2006

The albumin fraction of the cotyledons of Pisum contains two major polypeptides which together make up 34% (17% each) of the total albumin fraction. Both of these albumins (Mr∼8000 and ∼22000) are cotyledon specific proteins. In many Pisum lines the Mr∼22000 fraction resolves into two components on Na‐dodecylsulphatepolyacrylamide gels. The Mr∼8000 polypeptide was broken down during germination and early seedling growth, indicating that it functions as a storage protein, while the Mr∼22000 polypeptides were degraded relatively slowly. The level of both of these polypeptides was markedly reduced under sulphur deficiency conditions, the Mr∼22000 components being affected to a lesser extent than the Mr∼8000 component. Consistent with this, when [35S]sodium sulphate was injected into the pedicel of control plants during seed development and albumins were isolated at seed maturity, polypeptides of Mr∼8000 and ∼22000 together accounted for a major proportion of the radioactivity in the total albumin fraction. The abundance and relatively high sulphur content of these two albumins could be significant factors in determining the nutritional value of pea seed proteins.
Effect of sitosterol on autoxidation rate and product composition in a model lipid system
Authors: Yanishlieva Nedyalka Vi. , Schiller Helmut
Published: October 2006

The effect of 5% sitosterol on the autoxidation of tristearin at 120°C was investigated. It was found that sitosterol caused a two‐fold increase in the process rate; this effect was unchanged at peroxide concentrations of up to 350 mEq kg−‐1. It was established that introduction of 5% sitosterol considerably increased the concentration of oxidised products in tristearin (from 0.5 to 6.5%) after oxidation at 120°C for 7h. The degree of oxidation of sitosterol in the system was found to be 56%. The structure and composition of oxidised products in the two lipid systems (tristearin, and tristearin+5% sitosterol) were determined. Conclusions were drawn concerning the effect of the lipid medium on the composition and structure of the products of sitosterol autoxidation.
Characterisation of chicken pancreas α‐amylase isozymes and interaction with protein inhibitors from wheat kernel
Authors: Buonocore Vincenzo , Giardina Paola , Parlamenti Roberto , Poerio Elia , Silano Vittorio
Published: October 2006

Homogeneous chicken pancreas α‐amylase consists of two main isozymes which have been isolated by ion exchange chromatography; they show similar kinetic behaviour and inhibition patterns by two protein inhibitors from wheat, one monomeric (termed ‘inhibitor 0.28’) and one dimeric (termed ‘inhibitor 0.19’). Inhibitor 0.28 is the wheat kernel amylase inhibitor of Mr 12000 with a gel‐electrophoretic mobility relative to bromophenol blue of 0.28, while inhibitor 0.19 is the wheat kernel inhibitor of Mr 24000 with a relative mobility of 0.19. The chicken pancreatic enzyme was more effectively inhibited by the dimeric (Ki 3.7 nM) than monomeric inhibitor (Ki 570 nM); with both, the inhibition is dependent on pH, temperature and time of preincubation. Gel filtration, difference spectroscopy and kinetic studies have shown that molar combining ratios for amylase‐inhibitor 0.19 and amylase‐inhibitor 0.28 complexes are 1:1 and 1:2 respectively. Difference spectra of both amylase‐inhibitor complexes indicate that structurally related tryptophanyl side chains are involved in the binding of the two inhibitors to the enzyme. In conclusion, the interaction between chicken pancreas α‐amylase and inhibitor 0.19 or 0.28 fits the model proposed for amylase‐wheat inhibitor interactions.