bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural plant enzyme inhibitors. Isolation and characterisation of a trypsin/chymotrypsin inhibitor from indian red wood (Adenanthera pavonia) seeds
Authors: Prabhu K. Sudhakar , Pattabiraman Thillaisthanam N. 
Published: October 2006

AbstractA trypsin/chymotrypsin inhibitor was isolated from Indian red wood seeds by extraction with 0.01m HCl, chromatography on diethyl amino ethyl‐cellulose, ammonium sulphate fractionation and gel chromatography on Sephadex G‐100. The homogeneity of the final product was ascertained by affinity chromatography on trypsin sepharose and chromatography on phenyl sepharose CL‐4B columns. During all stages of purification and characterisation the ratio of activities against trypsin and chymotrypsin remained constant at about 1.1:1 indicating that the same factor is responsible for both activities. The size of the inhibitor was found to be 24 000 daltons based on gel chromatographic studies on Sephadex G‐100 and by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis. The molar ratio of interaction between the inhibitor and bovine trypsin for complete inactivation of the enzyme was found to be 1.04:1. Electrophoretic and gel chromatographic studies indicated that the purified inhibitor is capable of undergoing aggregation to form dimers and trimers. Even in the presence of sodium dodecyl sulphate and sodium dodecyl sulphateurea, this phenomenon was discernible. The binding sites on the inhibitor for trypsin and chymotrypsin were not mutually exclusive, based on the data from mixed enzyme studies and on analysis of the inhibitor‐enzyme complexes by gel chromatography on Sephadex G‐100. Modification of the arginyl residues of the inhibitor resulted in the loss of more of the antitryptic activity than of antichymotryptic activity. Conversely, modification of amino groups resulted in the loss of more of the antichymotryptic activity. The inhibitor was stable to exposure to a wide range of pH (1.0–12.0), but it was completely inactivated on heat‐treatment at 100°C for 15 min. The mode of inhibition of trypsin as well as chymotrypsin was non‐competitive and Ki values for the inhibitor were 2.92 × 10‐10M and 4.46 × 10‐10M, respectively, for the two enzymes.
The uptake of 15N‐labelled fertiliser by winter wheat and its immobilisation in a clay soil after direct drilling or ploughing
Authors: Dowdell Rodney J. , Crees Rachel 
Published: October 2006

AbstractThe uptake of fertiliser nitrogen (N) by winter wheat was measured using 15N‐labelled calcium nitrate applied at 80 kg N ha‐1 rate in May to the soil in microplots contained by sections of rigid PVC tube (30 cm diameter, 20 cm long), inserted into a calcareous clay soil (Evesham series). The microplots and surrounding plots had been subjected to either 5 or 6 years of continuous ploughing or direct drilling or 1 and 2 years of direct drilling after 4 years of deep‐tined cultivation. The recovery of fertiliser N labelled with 15N in the crop plants at harvest was in the range 60–67% of that applied in the first year and 0.5–0.7% in the second year; there were no significant treatment differences. The ‘apparent’ recovery of fertiliser based on a comparison of plots with and without fertiliser N was greater and ranged from 77–111 % of that applied. Estimates of the contribution of non‐fertiliser N to the crop by means of 15N analysis suggest that if this N had been utilised with the same efficiency as that of fertiliser N about 120 kg N ha‐1 was available to the plants. This represents about 1% of the total N in the soil to 80 cm depth. Soil analysis (0–15 cm) showed that about 8% of the applied 15N was retained in the upper layers of the soil; there were no treatment differences. Any changes due to mineralisation of the soil organic matter during the 2 years of the experiment were within the errors of the experiment.
The composition of acyl lipids and tocopherols in wheat germ oils from various sources
Authors: Barnes Peter J. , Taylor Philip W. 
Published: October 2006

AbstractThe compositions of acyl lipids, fatty acids and tocopherols were determined for a series of laboratory‐extracted and commercial wheat germ oils and a comparison made of the total carotenoid contents. High‐performance liquid chromatography (h.p.l.c.) with fluorescence detection was used to determine tocopherols and tocotrienols without the need for pretreatment of the oils. The laboratory‐extracted oils were similar in composition except for the content of free fatty acids and the β‐tocotrienol derived from bran in the unpurified mill germ; carotenoid content was lower in oil from rancid or cooked germ. The commercial oils contained very low concentrations of carotenoids and polar lipids and three samples had unusual tocopherol compositions very different from those of the laboratory‐extracted oils. One of these samples contained no detectable amount of linolenic acid which is usually present in cereal oils. It is concluded that the quality and composition of commercial wheat germ oil is very variable and that methods of assessing quality and detecting adulteration are essential. H.p.l.c. with fluorescence detection is well‐suited to the analysis of tocopherols, tocotrienols and α‐tocopherol acetate in wheat germ oil.
Potential artefacts from using porous polymers for collecting aroma components
Authors: Lewis Mervyn J. , Williams Anthony A. 
Published: October 2006

AbstractExamination of the components produced by heating Porapak Q and Tenax GC above their normal operating temperatures revealed the presence of hydrocarbons, benzaldehyde, ethylbenzaldehyde, acetophenone, ethylacetophenone, isopropylbenzyl alcohols, diacetylbenzene, phenol and furans, all of which could potentially occur as artefacts when using these porous polymers for collecting and concentrating aroma components from foods.
Thermal denaturation of proteins in Post rigor muscle tissue as studied by differential scanning calorimetry
Authors: Stabursvik Eva , Martens Harald 
Published: October 2006

AbstractPost rigor bovine M. semimembranosus was analysed by differential scanning calorimetry (d.s.c.). After extractive removal of sarcoplasmic proteins, subsequent pH adjustment and manual connective tissue removal, d.s.c. yielded reproducible thermograms which permitted investigation of the individual major myofibrillar proteins in various pH and salt environments without prior isolation. The positions of two major peaks, interpreted as myosin transitions, proved to be strongly pH dependent. At pH 5.4, the peak maxima occurred at 58 and 65°C, respectively, at a heating rate of 10°C min‐1. Above pH 6.5 their order of denaturation was reversed. In the pH range 5.4–6.5 the peak ascribed to actin had its maximum near 80°C in intact muscle. Above this pH range it was displaced to lower temperature. The thermal stability of actin was studied after treatment of the muscle tissue with different salt solutions. At equal ionic strengths (μ = 0.15) at pH 5.5, calcium chloride and sodium chloride caused 6.5°C and 4°C displacement to lower temperature, respectively. The thermograms of bovine semimembranosus muscle were compared to those of two red and two white muscle types (bovine cardiac and rabbit soleus muscles, chicken breast and rabbit semimembranosus muscles, respectively) at two pH levels. Greater myosin differences were found between red and white muscles than between muscles from different animal species. All muscles gave similar actin transitions, with exception of the heart muscle where the actin peak appeared at 3 °C lower temperature. The necessity of a strict pH control in order to obtain reproducible muscle thermograms is demonstrated.
Activities of cathepsins A and D in cod muscle
Authors: McLay R. 
Published: October 2006

AbstractCathepsin A has been demonstrated in cod muscle. Cathepsins A and D were partially separated and purified from cod muscle. Cathepsin A and D are essentially similar to those from other sources. Cathepsin A acts optimally on the synthetic substrate CBZ‐α‐L‐glutamyl‐L‐tyrosine at pH 5.0, whereas cathepsin D hydrolyses haemoglobin optimally at pH 3.8. Cathepsin D did not hydrolyse the synthetic peptides acted upon by cathepsins A, B or C.
The preservation of spent brewers' grains by the application of intermediate moisture food technology
Authors: Lilly Victor , Birch Martin , Garscadden Bryan 
Published: October 2006

AbstractSpent brewers' or distillers' grains are normally disposed of either in the wet form, in which they spoil rapidly, or after drying, which is costly. Alternatively, the storage life of wet grains may be extended by ensiling, which involves on‐farm control and equipment. This investigation examines the preservation of spent grains by lowering the water activity of the material using molasses and further stabilising the mixture by incorporating an anti‐mycotic agent. Investigations at both laboratory‐scale and pilot‐scale are reported culminating in the successful stabilisation of the wet grains by the incorporation of 30% of beet molasses and 0.3% of potassium sorbate into the grains after preliminary centrifugation. For effective preservation the stabilised grains should be consolidated in plastic bags followed by closing to leave the minimum possible headspace in the bags.
The natural variation of the pulegone content in various oils of peppermint
Authors: Farley Derek R. , Howland Valerie 
Published: October 2006

AbstractA total of 375 samples of American peppermint oil from three consecutive crops 1977–1979 grown in Eastern Oregon USA were analysed by gas‐liquid chromatography (g.l.c). The pulegone content showed large variations in samples from different fields. This variation in percentage pulegone composition was shown to be directly related to the harvest date. The pulegone content of first year mint normally harvested at the end of the season was found to be very low when compared to older mints harvested earlier, and to other commercially available peppermint oils from various countries of origin. The pulegone content of the commercially available samples showed large variation with origin.
Vegetable milk processing and rehydration characteristics of bambara groundnut [Voandzeia subterranea (L.) thouars]
Authors: Poulter Nigel H. , Caygill John C. 
Published: October 2006

AbstractEight cultivars of bambara groundnut [Voandzeia subterranea (L.) Thouars] were studied to determine their rehydration characteristics. Seeds from all cultivars approximately doubled their weight after 36 h and were then easily dehulled. Losses of nutrients to the soak water during this period were small. Mature seeds from one cultivar were evaluated for suitability as a base for a vegetable milk. Homogenisation of whole seed flour in water together with coconut or soya bean oils yielded an emulsion containing 20 g protein (Nx 5.71) and 30 ml oil litre‐1. Good emulsion stability was maintained after pasteurisation. Curds, similar to those traditionally prepared from soya beans, were easily prepared from bambara groundnut milk. The bland, creamy‐white product which was high in protein had a trypsin‐inhibitor content very much lower than that of the untreated vegetable milk.
Heat stability of endo‐polygalacturonases of Mucoraceous spoilage fungi in relation to canned fruits
Authors: Harris Jane E. , Dennis Colin 
Published: October 2006

AbstractThe heat resistance of endo‐polygalacturonase (endo‐PG) of the strawberry spoilage fungi, Rhizopus sexualis, R. stolonifer and Mucor piriformis, was compared to that of isolates of R. arrhizus, R. stolonifer and R. oryzae known to cause breakdown of canned apricots. All species produced endo‐PGs in culture medium which showed marked heat tolerance and a bimodal heat stability. Heating for 10 min at temperatures between 30–120°C indicated that maximum inactivation occurred at 50–60°C. Stability increased from 70°C to 100°C and then declined, but in some cases activity remained even after heating at 120°C for 10 min. Similar trends in heat resistance were recorded for endo‐PGs in infected tissue of apricot, peach, tomato and cherry fruits, whereas those in infected tissue of strawberry, raspberry and plum were rapidly inactivated at all temperatures above 40°C. The possible reasons for differences between fruits are discussed.
Post‐harvest application of diphenylamine and ethoxyquin for the control of superficial scald on Bramley's seedling apples
Authors: Johnson David S. , Allen John G. , Warman Timothy M. 
Published: October 2006

AbstractRecent changes in the antioxidant regulations in the UK and the need to evaluate the effectiveness of scald control chemicals in the presence of other post‐harvest chemicals led to a comparative study of the effects of diphenylamine (DPA) and ethoxyquin on scald development in Bramley's Seedling apples. A range of concentrations (1000–4000 mg litre−1 a.i.) of DPA completely controlled scald on Bramley apples kept in controlled atmosphere storage for 241 days; ethoxyquin at equivalent rates was less effective. Only partial control of scald was achieved with 500 mg litre−1 a.i. DPA. None of the treatments injured the fruit. Control of scald by 2000 mg litre−1 a.i. DPA or ethoxyquin was not impaired by adding thiophanate‐methyl (l g litre−1 a.i.) or calcium chloride (10 g litre−1) although the measure of control was reduced when both fungicide and calcium chloride were added. Calcium chloride caused lenticel injury which was aggravated by adding ethoxyquin but reduced by incorporating DPA. The concentrations of ethoxyquin and DPA residues on the fruit immediately after treatment were within the limits required by UK legislation (see reference 1) of 3 mg kg−1 and 10 mg kg−1, respectively, even where 4000 mg litre−1 had been applied. An initial residue concentration of 2.3 mg kg−1 DPA was associated with complete control of scald. Residue levels, particularly of DPA, declined rapidly during the first month of storage.
Differential scanning calorimetric study of meals and constituents of some food grain Legumes
Authors: Wright David J. , Boulter Donald 
Published: October 2006

AbstractTwo thermal transitions were observed in soya bean meal by differential scanning calorimetry (DSC) and on the basis of previous data were ascribed to the denaturation of the 11S globulin, glycinin, and the 7S globulin, β‐conglycinin. Three DSC transitions were apparent in Vicia faba meal; one was associated with starch gelatinisation, and was absent from thermograms of soya bean because the latter stores oil rather than starch. The remaining two transitions were identified with the 11S globulin, legumin, and a 7S globulin, vicilin. The denaturation parameters of legumin and glycinin were very similar, in contrast to those of vicilin and β‐conglycinin. From this it was concluded that legumin and glycinin probably represent homologous proteins, whereas the two 7S proteins possess intrinsically different structures to one another. Cowpeas (Vigna unguiculata) and dry beans (Phaseolus vulgaris) afforded two major transitions which were assigned to 7S globulins and starch. From its DSC profile, the 7S globulins of cowpea appeared heterogeneous, but nevertheless possessed denaturation characteristics similar to those of vicilin of V. faba. In contrast, the thermal behaviour of the 7S globulin of dry beans (glyco‐protein II) was distinct from that of any of the other 7S globulins investigated. Three protein transitions were observed in the three lupin species examined. As in the case of soya bean, no starch transition was present. On the basis of the correspondence in transition temperature, one of the protein transitions was assigned to the 11S globulin component. Overall, this study indicates the potential of DSC as a means for obtaining data on seed protein homology from whole meals rather than the extracted proteins.
The determination of myo‐inositol hexakisphosphate (phytate)
Authors: Cosgrove Dennis J. 
Published: October 2006

AbstractA method for the determination of myo‐inositol hexakisphosphate (phytate; P6‐myo‐inositol) in plant material has been devised which involves the extraction of the sample with 0.3m trichloroacetic acid (TCA), application of the diluted extract to an anion‐exchange resin column in the TCA form, and elution of all phosphoric esters, other than P6myo‐inositol, with 0.1M TCA. P6‐myo‐inositol is then eluted from the column with 1.0M HCl and a suitable aliquot of this solution is assayed for phosphorus.
Potential use of fruit waste containing in vivo De‐esterified pectin as a thickener in canned products
Authors: Speirs Charles I. , Blackwood Graeme C. , Mitchell John R. 
Published: October 2006

AbstractOrange peel and tomato skins were treated with sodium carbonate to pH 8.5 to cause in vivo pectin de‐esterification principally by pectinesterase action. The resulting material was dried and powdered and then evaluated for thickening properties in canned systems. It was found that after autoclaving for 75 min at 121.1 °C in a rotating retort in the presence of guar gum, sodium tripolyphosphate and calcium sulphate dihydrate, high post process viscosities could be obtained when orange peel was included at a concentration of 0.5% provided the pectin degree of esterification was reduced below 20% and the intrinsic viscosity of the pectin measured after extraction was above 3 dl g−1. Thickening was also obtained with tomato skins providing these two conditions were fulfilled. The dependence of viscosity on the calcium level and the thixotropic nature of the solutions obtained after processing, demonstrate that a calcium pectate gel can be formed even after severe heat treatment at a neutral pH. It is suggested that fruit and vegetable material containing in vivo deesterified pectin may be of value as a thickener in canned foods.
Survival of Vibrio parahaemolyticus during freezing
Authors: Lamprecht Engela C. 
Published: October 2006

AbstractThe ability of Vibrio parahaemolyticus to survive on frozen rock lobster tails was investigated. Rock lobster tails were artificially inoculated with the organism and were stored at − 18°C. Vibrio died off within 1 week at −18°C in lightly contaminated tails but a heavy infection survived for a few months at this temperature. Recovery depended on the degree of infection, the presence of other bacteria and the selectivity of the medium.
Loaf volume and the intrinsic viscosity of glutenin
Authors: Ewart John A. D. 
Published: October 2006

AbstractThe intrinsic viscosities of glutens and glutenins from 36 English‐grown wheat samples (from 25 varieties including specimens from four countries in Europe) were highly correlated with their loaf volumes per gram of protein. At least 98% of the gluten protein appeared to be dissolved. If it is assumed that intrinsic viscosity of wheat proteins is correlated with molecular weight, as is found for linear macro‐molecules, these results mean that the molecular weight of the glutenin is an important contributor to the baking quality of wheat. The intrinsic viscosity of glutenin from a Canadian Western Red Spring wheat was higher than that of all the English wheats. It did not yield a good loaf volume because it was baked on a regime suitable for weaker wheats. Durum and barley fitted into the correlation pattern. A heat‐damaged wheat did not, and this and other evidence led to the inference that heat damage may be due to cross‐linking of glutenin molecules so that the molecular weight remains high but the ability to swell and form a continuous matrix is impaired. Genetic factors, rather than environmental, seem the more important in controlling the intrinsic viscosities of gluten and glutenin since no significant variations were detected when eight varieties were grown at more than one site or, in two cases only, in different years. Experimental proof that ηr could be adequately calculated as a ratio of efflux times was obtained.
Effect of genotype and environment on vicine and convicine levels in fababeans (Vicia faba minor)
Authors: Pitz Walter J. , Sosulski Frank W. , Rowland Gordon G. 
Published: October 2006

AbstractThe concentrations of vicine and convicine (1.94 and 0.83%, dry basis, respectively) in fababeans were highest in young seeds and decreased rapidly with maturity. By 21‐28 August 1978 the concentrations had levelled off and the rank order of four cultivars, which differed widely in days required to mature, remained unchanged for the rest of the growing season. Analysis of variance on 36 fababean cultivars grown at different locations and years in Saskatchewan showed that genotype and environment had highly significant (P=0.01) effects on the glucoside level of fababean samples. Although lower in concentration (mean=0.31%), convicine showed greater variability among cultivars than vicine (mean = 0.66%). The glucoside contents of 242 diverse cultivars grown at Saskatoon ranged from 0.44 to 0.82% for vicine and 0.13 to 0.64% for convicine with the lowest cultivar containing 0.62% total glucoside. Individual seeds of a cultivar differed greatly in glucoside content and could become another source of variability for plant breeding and selection of low‐glucoside cultivars. Hulls were relatively free of glucosides but, despite variations in hull content, it was unnecessary to dehull samples before analysis.
Protein quality of a snack food
Authors: Jones Gwyn P. , Tucker Daryl J. , Woodruff Ian 
Published: October 2006

AbstractThe effect of factory processing and commercial end‐cooking on the protein quality of a popular snack food product made with meat, soya, vegetables and cereals (annual production = 10 000 t) was investigated. No change could be detected in either the content of fluorodinitrobenzene‐reactive lysine or the total levels of other amino acids as determined by ion‐exchange chromatography.
The effect of processing on the texture of canned mung bean (Phaseolus aureus) shoots
Authors: Taylor Andrew J. , Brown Jacqueline M. , Downie Lucinda M. 
Published: October 2006

AbstractThe effect of various processing regimes on the pectic substances and the final texture of canned mung bean shoots has been studied. A blanching temperature of 75°C for 30 s was optimal in activating the native pectinesterase of the shoots and a holding temperature of 55°C for an optimal 30 min led to maximal deesterification of pectin. This treatment resulted in a canned product that was superior to a sample blanched at 100°C.; the addition of calcium ions did not improve the product.
The nutritive value for rats of high‐ and low‐tannin sorghums treated with magadi soda
Authors: Muindi Pancras J. , Thomke Sigvard 
Published: October 2006

AbstractGrain sorghums containing 1.3, 0.7 and 0.5% tannins were treated with unrefined Magadi soda (37.5 g litre−1) for 3 days at 25°C and evaluated in a bioassay with male weanling rats. The alkaline treatment of the samples containing 1.3 and 0.7% tannins was found to significantly increase the digestibility of crude protein, crude carbohydrates and energy and to improve the biological value (BV) of the protein. Such an effect was not found for the third sorghum cultivar (0.5% tannins).
A property‐activity approach to relating ‚flavour’︁ thresholds in one substrate to their value in a second substrate
Authors: Gardner Ronald J. 
Published: October 2006

AbstractThe ratios of the logarithms of reciprocals of flavour (combined odour/taste) or odour, thresholds in aqueous and oil media can be significantly linearly related to the octanol/water partition coefficients (as log P) of the compounds considered. The use of this lipophilicity parameter to relate thresholds determined in different media may allow the estimation of thresholds in oil media, or oil‐based food products, from the thresholds in water.