bluuebunny/crossref_metadata_2025_split huggingface dataset:
An evaluation of enzymic and autolytic assays for cyanide in cassava (Manihot esculenta, crantz)
Authors: Cooke Rodney D. , De La Cruz Elba M. 
Published: October 2006

AbstractThe total cyanide contents of cassava parenchymal tissue (peeled roots), cassava cortex (peel) and cassava leaves were evaluated by autolytic and enzymic assays. Autolysis of parenchymal tissue was studied under different conditions of pH, time and temperature and addition of exogenous enzyme and antibiotic. Optimal conditions were determined to be 24 h at 37°C in acetate buffer (0.1M; pH 5.5) with 0.1 mg ml−1 chloramphenicol. Total cyanide contents similar (about 90%) to those obtained by enzymic assay could be achieved only by the use of small sample sizes: < 1 g of parenchymal tissue, < 0.3 g of cortex and < 0.1 g of leaf tissue. This caused sampling problems because of the presence of cyanide gradients in cassava tissues, which could only be resolved by tissue homogenisation prior to analysis. A study using the enzymic assay of cyanide stability in such homogenates, at different pH values and temperatures, has indicated that subsampling must be done within 15 min so as to prevent appreciable losses in the measured cyanide contents. The rate of loss of total cyanide was found to depend not only on the proportion of total cyanide which is non‐glucosidic (free), but also on the proportion of the non‐glucosidic cyanide present as cyanohydrins. The implications with regard to residual cyanide contents on cassava processing and the advantages of the enzymic assay over autolytic methods are discussed.
The effects upon digestion in sheep of the dietary inclusion of additional salivary salts
Authors: Hadjipanayiotou M. , Harrison D. G. , Armstrong D. G. 
Published: October 2006

AbstractFour mature Suffolk × half bred wether sheep, fitted with rumen fistula and re‐entrant cannulae at the proximal duodenum and terminal ileum were given in sequence, a control diet (diet 1) and that diet supplemented with either 20 or 40 g saliva salt kg−1 (diets 2 and 3 respectively). The addition of 20 g salt kg−1 failed to alter significantly the rumen fermentation pattern and dilution rate. In contrast, the feeding of diet 3 resulted in a significant increase in the molar proportions of ruminal acetate, a non‐significant decrease in propionate and a significantly higher rumen dilution rate (D), which was positively correlated with the molar proportions of acetate. Ruminal NH3‐N concentration tended to increase with salt supplementation, with the greatest concentration being observed at the highest level of salt inclusion. The presence of the salts significantly reduced the degradability of the feed protein within the reticulorumen. The dietary inclusion of the salts resulted in a non‐significant increase in total amino acid N (TAA‐N) and a significant increase in the organic matter entering the small intestine.
Effect of sulphydryl and disulphide compounds on the formation and quality of thermal aggregates of soya bean 11S globulin
Authors: Yamagishi Tatsunori , Yamauchi Fumio , Shibasaki Kazuo 
Published: October 2006

AbstractThe precipitate (thermal aggregates) formed in the presence of sulphydryl compounds > 0.01M [β‐mercaptoethanol (ME), gutathione (reduced form) (GSH), and cysteine (oxidised form) (Cys)] consisted of a basic monomer subunit and oligomerised sub units but did not contain polymerised subunits. The content of the basic subunits in the precipitate increased with increasing concentrations of sulphydryl compounds, and on addition of 0.5M ME reached a level of 90% or more of the precipitate. The time course of the formation of the basic monomer subunit and oligomerised subunits showed that basic monomer subunits tended to be precipitated at the initial stages of heating. This was followed by the formation of oligomerised subunits. Heating an 11S globulin solution containing sulphydryl compounds accelerated the precipitation reaction. However, this did not produce a high degree of polymerisation due to sulphydryl‐disulphide interchange. A scanning electronmicroscope image of thermal aggregation induced in the absence of any sulphydryl compounds showed, however, that polymerisation has a major role in the formation of a network structure. The mechanism of oligomer and polymer formation is discussed here.
Fluorescence of fish muscle: Description and measurement of changes occurring during frozen storage
Authors: Davis Harry K. 
Published: October 2006

AbstractChanges were observed in the fluorescence of skeletal muscle of many species of fish during storage in the frozen state. As intrinsic pyridine nucleotide fluorescence associated with degree of freshness, faded, two other visible fluorochromes developed. Production of the latter was favoured by minimal pre‐freezing delays, protection from air, low pH and high cold‐store temperatures. The results suggest that careful visual examination of fish muscle fluorescence, before and after thawing, could be useful in the assessment of cold storage history.
Studies on lipoxygenase from rice (Oryza sativa L.)
Authors: Sekhar B. P. S. , Reddy G. M. 
Published: October 2006

AbstractLipoxygenase activity was studied in 10 scented and two non‐scented rice varieties. Kinetic studies at different pH levels and time intervals revealed that the optimal activity was exhibited around pH 8 and at 15 min. Specific activities ranged from 40–85 units mg−1 protein and all the scented varieties had lower values that non‐scented ones.
Response of the muscles of growing pigs to dietary lysine levels
Authors: Balogun Oluwafemi O. , Fetuga Babatunde L. , Oyenuga Victor A. 
Published: October 2006

AbstractTwo independent experiments were conducted to investigate the response of the muscles of two classes of pigs (10 kg and 23 kg liveweight) to varying levels of total lysine in diet. The two classes were given diets of 20 and 18 % crude protein based on yellow maize and ground‐nut cake supplemented with graded levels of L‐lysine monohydrochloride. Total lysine level in the diets ranged between 0.52 and 1.42% for 10 kg pigs and 0.50 to 1.20 for the 23 kg pigs. Only bicep femoris, psoas major, longissimus dorsi and quadricep femoris were significantly (p < 0.05) influenced by total dietary lysine level. Both adductor and tricep brachii showed greater sensitivity to extreme deficiency of lysine in diet. At the end of the experimental periods, the muscles were over 100% above their initial weights at any dietary level except adductor and tricep brachii of pigs fed 0.50% total lysine in diet. While 1.02% total lysine in diet will promote optimum development of the muscles of 10–23 kg pigs, a lower amount of lysine in diet ranging between 0.7 and 0.9 % will be adequate for positive encouragement of the growth of the muscles of 23–62 kg pigs. The exponents of Huxley's allometry equation gave an estimation of the order of maturity of the ten muscles investigated in the two classes of pigs. In the 10–23 kg pigs, adductor grew fastest and gastrocnemius grew slowest relative to the total weight of the muscles. In the 23–62 kg pigs, bicep femoris grew fastest and psoas major slowest. The percentage of individual muscle gain which could be attributed to a different ‘sensitivity’ of most of the muscles to dietary lysine concentration in 10–23 kg and 23–62 kg ranged from 30 to 40% and 27 to 69% respectively. The data tend to suggest that gastrocnemius in 23–62 kg pigs was least influenced by the size of the muscles per se (R2=0.27) and was possibly the most ‘sensitive’ to dietary lysine concentration.
The nutritional value of dried skim milk in the diet of laying hens
Authors: Stevenson Mary H. , Jackson Norman 
Published: October 2006

AbstractAn experiment is reported in which dried skim milk was used at levels of 0, 40, 80, 120 and 160 g kg−1 of diet to replace mainly soyabean meal in the diets of two breeds of laying hens. AME and AMEn were significantly adversely affected by the two highest levels of added dried skim milk. Food conversion efficiency and bodyweight were unaffected by the added dried skim milk. Although overall food intake and egg number were not statistically significantly affected by dietary treatment there was a tendency towards a decline in both variables at the highest level of dried skim milk inclusion. The response of mean egg weight to increasing levels of dried skim milk was positively linear. Total egg weight was significantly affected by dietary treatment, the response being quadratic.
Residues of ethoxyquin in poultry tissues and eggs
Authors: Hobson‐Frohock Anthony 
Published: October 2006

AbstractTissues of broilers raised experimentally on diets containing the feed antioxidant ethoxyquin (6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydroquinoline) contained very low levels of this compound (<0.005 mg kg−1) both raw and after roasting. Residues were higher in liver (up to 0.063 mg kg−1) and highest in what appeared to be the major deposition site, the body fat (0.215 mg kg−1). The body fat of commercial broiler samples showed much lower levels (0.015‐0.051 mg kg−1). Leg and breast muscles from laying hens after 30 weeks on the experimental diets had low ethoxyquin levels (< 0.005 mg kg−1) with a higher liver content (0.048 mg kg−1) and again the highest level in the body fat (0.238 mg kg−1). Eggs from these hens contained 0.031 mg kg−1 ethoxyquin, probably all in the yolk. Market samples of eggs from five major producers gave an average value of 0.011 mg kg−1. A rapid and considerable loss of ethoxyquin occurred in the feed troughs, the concentration dropping from 125 mg kg−1 to 90 mg kg−1 in four hours.
The fatty acid composition of Hibiscus sabdariffa seed oil
Authors: Ahmed Wahab K. Abdel , Hudson J. F. Bertram 
Published: October 2006

AbstractAnalysis of Hibiscus sabdariffa seed oil from different seed collections (or cultivars), representing different growing areas, showed differences in the fatty acid pattern, especially with respect to linoleic (30.1‐37.45%) and epoxyoleic (trace to 5.3%). The results showed different values from those previously reported for the cyclopropenoid fatty acid, found to be malvalic acid (0.4‐2.0%), responsible for the positive Halphen response of the oil. It is now also established that the oil contains dihydrosterculic acid (1.0‐1.6%) which has been reported previously in other species of the genus Hibiscus. The results of the rest of fatty acids showed ranges for myristic 0.2‐0.5%, palmitic 17.4‐22.6%, stearic 3.9‐5.2% and oleic acid 34.6‐39.8%.
The nutrient content of UK wheat flours between 1957 and 1980
Authors: Wenlock Robert W. 
Published: October 2006

AbstractThe British Government's Voluntary Flour Sampling Scheme was designed in 1957 to replace the National Flour Survey which had operated from the War years. With the cooperation of the milling industry, representative samples of wheat flours milled in the United Kingdom for human consumption were obtained by the Ministry of Agriculture, Fisheries and Food for nutritional analysis at the Laboratory of the Government Chemist. The Scheme has operated continuously since then and the results show that each type of flour has remained almost constant in nutritional composition with year‐to‐year variations 5% or less from the mean for almost all nutrients. As flour and flour‐based cereal products are consumed in large amounts, the data obtained have significant nutritional implications which are discussed in the context of the national average dietary intakes.
The effect of heating on the haemagglutinating activity and nutritional properties of bean (Phaseolus vulgaris) seeds
Authors: Grant George , More Linda J. , McKenzie Norma H. , Pusztai Arpad 
Published: October 2006

AbstractThe toxic lectins present in red, white and black kidney beans (Phaseolus vulgaris) are sensitive to heat treatment and the efficiency of that treatment is greatly improved by pre‐soaking of the seeds. Heating of pre‐soaked seeds at all temperatures above 75°C caused a continuous reduction in both their haemagglutinating activity and toxicity. However, the only safe method of eliminating toxicity was to heat the fully hydrated seeds to 100°C for a minimum of 10 min.
Gummosis of stone‐fruit trees and their fruits
Authors: Boothby Derek 
Published: October 2006

AbstractThe factors that affect gum formation in stone‐fruit trees share the common feature of stimulating ethylene production in plant tissues. It is suggested that ethylene might play an important role in gummosis. The chemical structure of the exudate gums is similar to that of certain cell‐wall polysaccharides and it is possible that gummosis is caused by excessive formation of these polysaccharides as a result of ethylene production in the tissues.
Effects of nitrogen fertilisers on the emergence of vegetable seedlings
Authors: Page E. Ronald , Cleaver Trevor J. 
Published: October 2006

AbstractDepression of percentage emergence of vegetable seedlings was linearly related to the quantity of nitrogen fertiliser applied when the fertiliser was broadcast and worked into the seed bed. Placement of fertiliser at a depth of 8 cm avoided depression of emergence. The extent to which emergence was affected depended on the weather, and on the crop, some species (e.g. lettuce) being sensitive, others (e.g. red beet) being resistant to the effects of nitrogen fertilisers. A computer program was used to calculate the effects of rainfall, evaporation and soil temperatures on the concentration of nitrate in the top 5 cm of soil in a series of 45 field experiments, and this was compared with the seedling emergence records. According to the program this concentration varied widely over short periods. Red beet and radish achieved a high percentage emergence after very brief periods of low nitrate concentration. For most crops, however, transient short periods of low nitrate concentration were insufficient for satisfactory emergence, and most crops exposed to high nitrate concentrations, even if these were not continuous, suffered some reduction of emergence. Spinach was able to resist a high concentration of nitrate during the 3 days after sowing, but not at later periods. The sensitivity of crops varied, and the period of sensitivity was also different for different crops. Methods of application of nitrogen fertilisers likely to avoid depression of seedling emergence are briefly discussed.
Volatile aroma constituents of kiwifruit
Authors: Young Harry , Paterson Vivienne J. , Burns Donald J. W. 
Published: October 2006

AbstractThe volatile constituents of kiwifruit (Actinidia chinensis Planch.) have been investigated. The volatiles were collected and concentrated using vacuum steam distillation and freeze concentration. The concentrated distillate was analysed by gas chromatography, gas chromatography‐mass spectrometry and reaction gas chromatography. Apart from methyl benzoate, all the components identified were alkyl and alkenyl esters, alcohols, aldehydes and ketones. The most abundant component was trans hex‐2‐enal. Odour evaluation of the components at the exit port of the gas chromato‐graph indicated that ethyl butanoate, hexanal and trans hex‐2‐enal are important contributors to the aroma of kiwifruit. One other component which does not show a peak in the chromatogram and which is not yet completely characterised may have particular significance.
Interactions between the kernel N sink, grain yield and protein nutritional quality of maize
Authors: Tsai Charles Y. , Warren Herman L. , Huber Don M. , Bressan Ray A. 
Published: October 2006

AbstractThe isogenic opaque‐2 (o2) and its normal counterpart of maize (Zea mays L.) hybrid ‘B14 × B37’ were used as a model system and grown under different levels of nitrogen fertility to test the importance of the kernel N sink (zein accumulation) relative to kernel osmotic potential, dry matter accumulation, grain yield and protein nutritional quality. Self‐pollination and reciprocal crosses were made with seven o2 hybrids and their normal counterparts in order to determine the effect of the kernel N sink and/or vegetative characteristics on kernel dry weight accumulation. The results indicate that with a small supply of nitrogen, both normal and o2 kernels produced only small amounts of zein, and kernel weights and grain yields were comparable. As the level of nitrogen increased, zein accumulated preferentially in normal, but not in o2, and differences in kernel weight and grain yield between these two genotypes became greater. The reduction of dry matter accumulation in o2 kernels relative to normal kernels when grown under high N levels may result from the accumulation of free amino acids and their catabolic products in the kernel as a consequence of a small N sink. These osmotica contributed to a more negative osmotic potential which may favour water movement, but reduce solute movement into the kernel. Increased zein accumulation in normal kernels enhanced kernel weight and grain yield but reduced protein nutritional quality. The concentration of lysine and tryptophan as a percentage of protein decreased as the level of N fertiliser and kernel protein in the normal kernel increased. On the other hand, the o2 mutant failed to deposit additional N as zein; therefore, the concentration of these two essential amino acids remained constant regardless of N levels. However, when lysine and tryptophan were expressed on an area (kg ha−1) basis, the amino acid yields of these two genotypes were comparable.
Assessing the colour of tomato fruit during ripening
Authors: Hobson Graeme E. , Adams Peter , Dixon Timothy J. 
Published: October 2006

AbstractThe use of colour to separate tomatoes into groups at distinct stages of ripeness is usually a subjective procedure. In an attempt to reduce variability, tomatoes previously sorted by eye into five categories from mature green to full red were reassessed using a tristimulus colour difference meter. Various methods of presenting the samples to the machine for colour testing and of transforming the results were compared, and a formula was developed so that objective limits for each ripening stage could be calculated. In order to obtain matched samples of fruit at any particular stage of ripeness, the instrument can be programmed to reject fruit falling outside the appropriate limits. The colour components of tomatoes of several cultivars chosen subjectively to be at the same stage of ripeness (orange‐red) were shown to be related to fruit firmness.
The volatile flavour components of commercial port wines
Authors: Williams Anthony A. , Lewis Mervyn J. , May Helan V. 
Published: October 2006

AbstractGas chromatographic‐mass spectrometric examination of aroma extracts from both Ruby and Tawny port has led to the identification of 141 components, notably 2‐methoxyphenol, dihydro‐2‐(3H)‐furanone, β‐methyl‐γ‐octalactone, cis‐4‐hydroxy‐methyl‐2‐methyl‐l,3‐dioxolane, ethyl pyroglutamate and vitispirane. Odour evaluation of the components separated by gas chromatography indicates five regions as being of potential importance in port. 2‐Methoxyphenol and dihydro‐2‐(3H)‐furanone were found in two of these regions, three others being associated with esters of succinic acid. None of these components can, however, wholly explain the port‐like odour.
Assessment of the antimetabolic effects of trypsin inhibitors from cowpea (Vigna unguiculata) and other legumes on development of the bruchid beetle Callosobruchus maculatus
Authors: Gatehouse Angharad M. R. , Boulter Donald 
Published: October 2006

AbstractInsect feeding trials were carried out whereby cowpea trypsin inhibitor (CPTI) was incorporated at various levels up to 10% in pelleted meals of both a susceptible variety of cowpea and another susceptible species of legume, the chickpea. The results confirmed that CPTI, prepared by affinity chromatography, is an effective antimetabolite against C. maculatus; furthermore, it is also effective when added to pelleted chickpea meals. Bioassays using soya bean trypsin inhibitor (SBTI) and lima bean trypsin inhibitor (LBTI) showed these protease inhibitors to be relatively ineffective. Methionine supplementation of meals of resistant cowpea resulted in increased adult survival from approximately 43 to 89% relative to the controls; addition of cysteine had a similar effect. Supplementation with both methionine and tryptophan, probably the next limiting amino acid in cowpea, did not increase adult survival any further. It is concluded that CPTI is an effective antimetabolite of C. maculatus and that this type of mechanism may be widespread. However, it relies upon a finely controlled balance within the host plant which has to make available sufficient nutrients for itself but insufficient to maintain predation since this example of resistance can be overcome by by‐passing the limiting sulphur amino‐acid block.
The composition of oat husk and its variation due to genetic and other factors
Authors: Welch Robert W. , Hayward Margaret V. , Jones D. Iorwerth H. 
Published: October 2006

AbstractThe composition of oat husk has been determined in (i) 11 diverse oat genotypes, (ii) current high‐yielding spring and winter varieties from trials in various regions of Britain, and (iii) samples obtained from two British oat mills. Husks were comprised mainly of cell wall (>83%) with about equal quantities of cellulose and hemicellulose (∼30‐35%). Lignin and ash contents were 2–10% and 3.5–9% respectively. Protein and oil contents were low (1.6–5% and 1–2.2%) and only a proportion of the protein (40–60%) and total oil (5–30%) were of apparent nutritional significance. Starch and water‐soluble carbohydrates were very low (<2% and <1%). Pepsin‐cellulase digestibility was low (7–14%) and it was negatively correlated with lignin content in the 11 genotypes. There were significant genetic differences in composition within both the 11 genotypes and the trial varieties; however, the range was small and there were significant differences due to location among the trial varieties. Husk, which was hand‐separated from oat mill samples, was generally inferior in quality to the genotypes and varieties. However, due to groat contamination, industrially separated samples from the oat mills were similar in composition to those from other sources. It is confirmed that oat husk is a poor quality feedstuff and the most significant improvement in grain quality could be made by breeding for reduced husk content.
The role of triglycerides and phospholipids in the aroma of cooked beef
Authors: Mottram D. S. , Edwards R. A. 
Published: October 2006

AbstractThe intramuscular triglycerides and the structural phospholipids were selectively removed from beef muscle by solvent extraction and the aroma of the residual material assessed after cooking. Removing triglycerides had little effect on the aroma of the cooked meat, but when both triglycerides and phospholipids were removed a marked difference in aroma was observed. The headspace volatiles from the different cooked meats were entrained on Tenax GC and analysed by combined gas chromatography‐mass spectrometry. The profile of headspace volatiles for the meat devoid of triglycerides was similar to that from an unextracted control and the major components were aliphatic alcohols and aldehydes. Removing phospholipids as well as triglycerides gave a markedly different volatile profile; the quantities of aliphatic aldehydes were considerably reduced and only traces of aliphatic alcohols were found, while the amounts of benzaldehyde and pyrazines were greatly increased. The latter explains some of the changes in roast aroma.