bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of chemical modification on the hydrolysis of fats by pancreatic lipase and pregastric esterase with reference to fat digestion in the pre‐ruminant calf
Authors: Hamilton Rosemary K. , Raven Alan M. 
Published: November 2006

AbstractThe hydrolysis of various dietary fats and pure triglycerides by pregastric esterase and pancreatic lipase was studied in vitro in conjunction with a series of digestibility trials to examine the effect of various chemical modifications to beef tallow on its digestibility in milk replacers for pre‐ruminant calves. Using pure triglycerides, it was shown that pregastric esterase preferentially hydrolyses triglycerides containing short chain fatty acids; the rate was highest with glyceryl tributyrate and decreased markedly with increase in chain length. Using butterfat, tallow and various modified forms of tallow, it was shown that the inclusion of butyric acid in tallow by interesterification, which markedly improved its digestibility, substantially increased its rate of hydrolysis by pregastric esterase. The initial rate of hydrolysis of tallow by pancreatic lipase was substantially less than that of butterfat. Little improvement in the rate of hydrolysis and solubilisation was obtained when the tallow sample was interesterified or when it was supplemented with the long chain fatty acids, myristic and oleic, or with the short chain fatty acid, butyric. A considerable increase in the initial rate of hydrolysis and solubilisation did occur with tallow samples with a reduced content of stearic acid.The results suggest that hydrolysis by pregastric esterase is a major site of discrimination between different fats in the pre‐ruminant calf and an important factor in determining overall digestibility.
Effects of protein content on the distribution and properties of rice protein
Authors: Juliano Bienvenido O. , Antonio Alicia A. , Esmama Bernardita V. 
Published: November 2006

AbstractThe protein of brown rice became more evenly distributed as protein content increased. Kjeldahl protein content of brown rice provided a better indication of milled rice protein content than histological examination of individual grains because protein content varied among grains. The increase in protein content was mainly due to an increase in the number of protein bodies. Screening 10 493 varieties from the world rice collection for lysine content by dye‐binding capacity showed that lysine content of rice protein varied only by at most 0.5 % point at any protein level. A negative correlation between the lysine content of protein and protein content of brown and milled rice was observed only in samples with protein below 10%. As protein content increased water‐soluble nitrogen also increased as a percentage of brown rice.
Effect of delignification on the in vitro rumen digestion of polysaccharides of bagasse
Authors: Dekker Robert F. H. , Richards Geoffrey N. 
Published: November 2006

AbstractSugar cane bagasse was partially delignified by three different chemical methods, viz. sodium sulphide/hydroxide (Kraft process), sodium hydroxide and sodium sulphite.The Kraft and alkali treatments each reduced the lignin content by about 55%, and increased the rumen dry matter digestibility (d.m.d., measured by an in vitro method) by over 170%. Treatment of the bagasse with sodium sulphite removed only 15% of the lignin and increased the d.m.d. by only 37%. The digestibility of hemicelluloses (measured as xylan and arabinan) and cellulose in delignified bagasse increased fourfold and twofold, respectively, for the Kraft and alkali treatments and twofold for the sodium sulphite treatment.
Measurement of non‐enzymic browning of dehydrated carrot
Authors: Baloch A. K. , Buckle K. A. , Edwards R. A. 
Published: November 2006

AbstractNon‐enzymic browning of sulphited dehydrated carrot is measured by extracting brown materials with 2% acetic acid containing 1% formaldehyde, followed by precipitation of interfering pigments absorbing at 420 nm with 10% lead acetate and ethyl alcohol. The presence of sulphur dioxide is shown to reduce the absorption at 420 nm of a glucose—glycine browning solution and an extract of dehydrated carrot, the effect depending on time of incubation and exposure to light. The use of formaldehyde in the extraction solvent overcomes the effect of sulphur dioxide at concentrations up to 19 200 parts/million. The presence of carotenoids is shown to increase the absorption of browning extracts at 420 nm leading to high results. The interference from pigment materials is overcome by precipitation with lead acetate and ethyl alcohol. The use of both formaldehyde and lead acetate has no additional effect on browning determinations.Comparative tests of the proposed lead‐alcohol precipitation method with an alcohol precipitation method, using both a glucose‐glycine browning mixture and an extract of dehydrated carrot, shows only the lead‐alcohol precipitation method to overcome errors due to carotenoid pigments either originally present in the extract or added as β‐carotene, while the additional use of formaldehyde during extraction is necessary to overcome errors due to sulphur dioxide.Browning of dehydrated sulphited carrot stored for up to 20 days at 50 °C decreased with time of storage when measured by the alcohol precipitation method and in dehydrated non‐sulphited carrot, browning showed only a slight increase with storage time. When measured by the lead‐alcohol precipitation method, browning showed only a slight increase in stored dehydrated sulphited carrot, but a marked increase in stored dehydrated non‐sulphited carrot, in agreement with visual observations.
The effect of potassium sulphite on the recovery of micro‐organisms from dehydrated onion
Authors: Moussa R. S. 
Published: November 2006

AbstractThe addition of potassium sulphite to onion powder and onion flake homogenates improved the recovery of several microbial groups constituting the aerobic flora of many onion samples. The counts of sulphite‐reducing anaerobic spores were not affected. A correlation is found between each sample's content of the pungent principle and the degree to which the addition of sulphite recovers its aerobic microbial flora.Aerobic spore‐forming bacilli, Gram positive and catalase negative streptococci, Gram and oxidase negative and occasionally pigmented bacilli and yeasts and moulds formed the greater part of the dehydrated onion flora. Escherichia coli was isolated in relatively low numbers from only 4 of the samples. All 243 samples showed a Staphylococcus aureus count of less than 10/g.
The effect of lipoxygenase action on the mechanical development of wheat flour doughs
Authors: Frazier P. J. , Leigh‐Dugmore F. A. , Daniels N. W. R. , Eggitt P. W. Russell , Coppock J. B. M. 
Published: November 2006

AbstractThe mechanical development of dough has been followed by measurement of the relaxation time of dough samples after mixing to various levels of work input. Parallel determinations of free and bound lipid have also been made. When doughs were mixed in air, addition of full‐fat, enzyme‐active soya bean flour (subsequently referred to as “soya flour”) resulted in an increase in relaxation time, particularly at higher work levels. The magnitude of this improvement increased with increasing work input and was dependent on the rate of work input. Addition of soya flour also enabled a higher level of mechanical work to be introduced before dough breakdown occurred. When doughs were mixed under nitrogen, or when the soya flour was heat denatured, no change in the rheological properties compared with the respective control doughs was found. The release of bound lipid, which occurred during dough development in air in the presence of soya flour, could also be induced by adding purified lipoxygenase to the dough, together with linoleic acid as a substrate. This resulted in rheological changes similar to those observed using soya flour. However addition of enzymically pre‐peroxidised lipid to doughs mixed in nitrogen was without effect on relaxation times. These findings suggest that lipid release is linked with structural changes in dough protein and provide further support for a mechanism of coupled oxidation of protein ‐SH groups by lipoxygenase.
The component fatty acids of chaulmoogra oil
Authors: Sengupta A. , Gupta J. K. , Dutta J. , Ghosh A. 
Published: November 2006

AbstractThe fatty acid composition of the seed oils of the species, Hydnocarpus kurzii, H. wightiana and H. odorata were determined by gas‐liquid chromatographic (g.l.c.) analysis. The percentages of individual fatty acids were found to be: hydnocarpic 23.0, 33.9, ‐; chaulmoogric 29.6, 35.0, ‐; gorlic 25.1, 12.8, ‐; lower cyclic homologues 0.3, 4.6, ‐; myristic 0.6, 0.8, 0.4; palmitic 8.4, 5.6, 11.8; stearic ‐, 0.6, 4.7; palmitoleic 6.0, 1.3, 0.5; oleic 5.4, 3.6, 21.8; linoleic 1.6, 1.8, 29.3; linolenic ‐, ‐, 31.2; respectively.
Thermal degradation of anthocyanins with particular reference to the 3‐glycosides of cyanidin. I. In acidified aqueous solution at 100 °C
Authors: Adams J. B. 
Published: November 2006

AbstractSeveral highly purified 3‐glycosides of cyanidin were degraded at 100 °C in weak aqueous hydrochloric acid at various pH values between 1 and 4 under both nitrogen and oxygen atmospheres and it was shown that the aglycone‐sugar bond is the most labile of the glycosidic bonds at pH 2 to 4. At pH 1.0, however, all the glycosidic bonds are susceptible to hydrolysis.Evidence is presented that phenolic aglycones, and glycosides of undetermined structure, are formed during anthocyanin degradation. An essentially colourless phenolic product, tentatively identified as the chalcone or α‐diketone of cyanidin, was observed during the breakdown of all the cyanidin‐3‐glycosides studied in the pH range 1 to 4. This compound is stable under anaerobic conditions but easily degraded in atmospheres of oxygen.The rate of sugar formation was found to be similar to the rate of red colour loss and to the rate of anthocyanin disappearance in the pH range 2 to 4 showing that glycosidic hydrolysis and not opening of the pyrylium ring is the rate‐determining step of the principal reaction leading to red colour loss. At pH 1.0 (anaerobic conditions), the rate of red colour loss lags behind the rate of anthocyanin degradation because the red, cationic form of cyanidin is fairly stable at this low pH. Complete hydrolysis of the anthocyanin takes place at pH 1.0 in contrast to the partial hydrolysis observed in the pH range 2 to 4.The qualitative and quantitative information reported in this paper led to the proposal of a mechanism for anthocyanin degradation and the red colour loss which accompanies it for the pH range 2 to 4.
Distribution of cell wall components in potato tubers: A new titrimetric procedure for the estimation of total polyuronide (pectic substances) and its degree of esterification
Authors: Warren Donald S. , Woodman John S. 
Published: November 2006

AbstractTotal esterified polyuronide in plant tissue can be assayed by titrating the uronic acid liberated from the alcohol‐insoluble fractions of the tissue by alkaline hydrolysis. The total polyuronide can be determined in a similar manner if the carboxyl groups are initially esterified with methanolic hydrochloric acid. Comparison of the two results gives the degree of esterification of the total polyuronide. The divalent metals present in the same alcohol‐insoluble fractions are assumed to be bound to the uronide groups and their assay gives a measure of the extent of interchain cross‐linking by metal salt formation.Application of these procedures to samples from different parts of potato tubers showed that polyuronide generally had a low degree of esterification (about 40%) and was present in higher concentrations (about 4.6% a.i.s.) in the cortex and periderm than in the interior tissues (about 2.7% a.i.s.). The degree of crosslinking due to calcium and magnesium ions is lowest in the outer layers of the potato tuber and may be the reason that sloughing occurs in this area.
Energy changes during ensilage
Authors: McDonald P. , Henderson A. R. , Ralton I. 
Published: November 2006

AbstractThe energy changes occurring during ensilage have been examined using a theoretical model with data calculated from known biochemical pathways. Results of a laboratory experiment in which five grasses were ensiled in triplicate confirm that energy is recoverable in an anaerobic system in spite of gaseous losses in the form of CO2. These changes have a concentrating effect upon the gross energy value of silage. The importance of this increase in energy concentration is discussed.
Effect of differential maturity of paddy grains in a panicle on their milling quality
Authors: Desikachar H. S. R. , Bhashyam M. K. , Ranganath K. A. , Mahadevappa M. 
Published: November 2006

AbstractBranches of paddy panicles were divided into four equal parts and grains collected from each part separately. Moisture content at harvest and milling breakage after shade drying of grains to 12 to 13% moisture were determined.Average moisture content of grains gradually increased while milling quality generally suffered in grains from the top first quarter to the last quarter at the bottom. The same trend was found when the grains in the “top” quarter were compared with those from the “rest” of the panicle. The proportion of sun‐checked grains was highest in the “top” fractions at all stages of maturity. The grains at the “top” also had a tendency to shed easily from the panicle. At early stages of maturity milling breakage of grains in lower portions of panicles was high perhaps due to immaturity and softness.
(−)‐3t,4t‐Dihydroxycyclohexane‐1c‐Carboxylate, a new quinate metabolite of Lactobacillus plantarum
Authors: Whiting G. C. , Coggins R. A. 
Published: November 2006

AbstractLactobacillus plantarum, isolate No. 13a, reduces (−)‐quinate, shikimate and (−)‐dihydroshikimate to a new metabolite identified as (−)‐3t, 4t‐dihydroxycyclohexane 1c‐carboxylate. The absolute stereochemistry of the product is given and is shown to resemble that of (−)‐quinic and (−)‐dihydroshikimic acids.
Some examples of the effect of soil physical conditions on the tractive effort required during ploughing
Authors: Low A. James , Piper F. Joan 
Published: November 2006

AbstractSome measurements have been made of the draw‐bar pull during autumn and late winter ploughing of soils of different texture and following different treatments. Periods under grass reduce the force required for ploughing. Farmyard manure applied at 75 t/ha annually was found to have lowered the draw‐bar pull on ploughing significantly after six years.
Nutritive value of processed Saccharomyces cerevisiae, Scenedesmus obliquus and Spirulina platensis as measured by protein synthesis in vitro in rat skeletal muscle
Authors: Omstedt Per T. , von der Decken Alexandra , Hedenskog Gudmund , Mogren Håkan 
Published: November 2006

AbstractRats were fed for six consecutive days on a diet containing the protein sources under test at a protein level of 20%. Protein synthesis by skeletal muscle ribosomes was measured in vitro. Synthetic activity was estimated per unit ribosomal RNA and per g of wet weight of muscle. In separate experiments the nitrogen efficiency ratio (n.e.r.) of the protein sources was determined after 21 days feeding at a 10% protein level.As measured by protein synthesis the nutritional quality of lyophilised baker's yeast Saccharomyces cerevisiae increased after mechanical disintegration. A further improvement was achieved by feeding yeast protein concentrates.Judged by these determinations the nutritional quality of the three yeast preparations was higher than that of the low‐quality protein, wheat gluten but did not reach the level of the high‐quality protein, casein supplemented with methionine.The metabolic utilisation of spray‐dried microalga Scenedesmus obliquus increased after mechanical disintegration from a value similar to that of wheat gluten to the level of methionine‐supplemented casein.Lyophilised Spirulina platensis had a nutritional quality between that of wheat gluten and casein supplemented with methionine.Addition of the limiting amino acid methionine to air‐dried baker's yeast or drum‐dried Scenedesmus obliquus and Spirulina platensis stimulated the metabolic utilisation of the micro‐organisms.Supplementation of the diet with methionine increased the nitrogen efficiency ratio of air‐dried yeast and of drum‐dried Scenedesmus obliquus but had no effect on drum‐dried Spirulina platensis. The ratios were significantly lower than those of casein supplemented with methionine.There was no difference in the nitrogen efficiency ratio between disintegrated yeast and yeast protein concentrate but the ratio of both was higher than that obtained with lyophilised yeast. The ratio was similar to that of casein without the addition of methionine.
A highly sensitive automated technique for the determination of ammonium nitrogen
Authors: Brown Michael W. 
Published: November 2006

AbstractThe catalytic action of nitroprusside on the phenol hypochlorite reaction has been utilised to design a more sensitive automated technique for determining ammonium nitrogen in soil extracts. The method gives reproducible results in close agreement with manual methods. Sensitivity is such that as little as 0.1 parts/ million of N in solution can be determined without the use of recorder range expansion.
Effects of storage treatments upon the ripening of conference pears
Authors: Knee Michael 
Published: November 2006

AbstractPreliminary work established the pattern of changes in the amounts and properties of soluble pectic polysaccharides in Conference pears during ripening at 10 °C.Conference pears were harvested on three dates and stored in air at −1 °C and in 2% O2 at −1 °C for various periods. They were ripened on removal from store at 18 °C. Chlorophyll and carotenoid concentrations in the fruit peel and soluble polyuronide concentrations in whole fruit as well as general storage data were recorded.The lag in the ripening of pears at 18 °C after harvesting was abolished by storage at −1 °C. Softening and pectin changes were similar in all stored fruit samples irrespective of picking date, period of storage and whether stored in air or 2% O2. Storage in 2% O2 did retard breakdown slightly, however.The main effect of 2% O2 was that it reduced the rate of destruction of chlorophyll during storage. Higher levels of chlorophyll were found during ripening in fruit which had been stored in 2% O2 than in fruit stored in air.
Fermented foods of common use in Egypt. II. The chemical composition of bouza and its ingredients
Authors: Morcos Sabry R. , Hegazi S. M. , El‐Damhougy Soraya T. 
Published: November 2006

AbstractThe nutrient content of different samples of bouza, either prepared in the laboratory or brought from the local market, were determined and compared with the individual ingredients.Changes that occur in the pH values, diastatic power, alcohol and nutrient content of bouza when fermented for 24, 48 and 72 h were also studied.
Effect of some citrus juice constituents on taste thresholds for limonin and naringin bitterness
Authors: Guadagni Dante G. , Maier Vincent P. , Turnbaugh Jean G. 
Published: November 2006

AbstractA panel of 20 to 27 screened judges was used to determine the threshold of pure limonin and naringin in distilled water, sucrose solutions, citric acid solutions adjusted to various pH values and in citrus juice model systems. Thresholds in distilled water were 1 and 20 mg/l for limonin and naringin, respectively. Sucrose, citric acid and combinations of these constituents in a model system increased the threshold of limonin and naringin several fold. The highest thresholds were obtained at low pH values in the absence of sugar. In a 1.2% citric acid solution containing 5% sucrose, 2.5% dextrose and 2.5% fructose the maximum limonin threshold of 11 mg/kg was obtained at pH 3.8. The maximum difference threshold for limonin in orange juice was 6.5 mg/kg and also occurred at pH 3.8. The optimum pH for limonin bitterness suppression (maximum threshold) was 3.8 in both model systems and natural orange juice. Thresholds on either side of this value were lower and limonin bitterness was more noticeable. No pH optimum was observed for naringin threshold in model systems. Individual thresholds showed a wide range of sensitivity to both limonin and naringin bitterness.
Storage of mushrooms in pre‐packs: The effect of changes in carbon dioxide and oxygen on quality
Authors: Nichols Royston , Hammond John B. W. 
Published: November 2006

AbstractMushrooms (Agaricus bisporus) were picked at the “button” stage (velum differentiated but unbroken) and stored for 3 to 5 days at 2 or 18 °C in styrene punnets (pre‐packs) overwrapped with one of a range of plastic films. Concentrations of carbon dioxide and oxygen were measured inside the pre‐packs at intervals. When the packs were opened, internal and external browning, loss of weight and diameter of the mushrooms were measured and subjective assessments of quality were made. These parameters were compared with those of mushrooms stored in unwrapped punnets.As a result of the mushroom respiration, the internal atmosphere of the prepack was rapidly modified until, after about 24 h, a rough equilibrium concentration of CO2 and O2 was established in the range 4 to 10% CO2 and 11 to 17% O2 at 2 °C or 8 to 15% CO2 and 1 to 2% O2 at 18 °C; the mean concentration was dependent on the type of film. An equation, applicable to five out of six films that were tested, is proposed to describe the relationship between the equilibrium CO2 concentrations at 18 °C and the permeability data of the film.At 18 °C, the gas changes inside the pre‐packs prevented opening of the pileus and, in combination with prevention of water loss by the film, slowed down deterioration of the mushrooms. However, concentrations of CO2 much above or below 10 to 12% were associated with increased internal browning. At 2 °C overwrapping generally caused slight external browning of the pileus.The relevance of the results are discussed in relation to the commercial marketing of pre‐packed mushrooms.
Protein quality of some Nigerian feedstuffs. II. Biological evaluation of protein quality
Authors: Fetuga B. L. , Babatunde G. M. , Oyenuga V. A. 
Published: November 2006

AbstractThe protein quality of some Nigerian protein concentrates were studied by conventional protein quality techniques using weanling albino rats of the Wistar Strain.The true digestibility of the concentrates were between 90 and 98% for most of the feedstuffs examined, except the cashew nut scrap kernel meals I and II, (84.6 and 84.3%); the African locust bean seed only (75.9%); the African locust bean seed and pulp (81.6%); and the palm kernel meal (74.2%) which showed significantly lower values than the others.The animal protein sources examined (milk powder, casein, fishmeals and egg) were found to show superior p.e.r., n.p.r., p.r.e., n.p.u. and b.v. values to those observed for the cashew nut samples, African locust bean seed, groundnut and palm kernel meal. Blood meal, however, could not support the growth of rats and showed poor protein quality indices: −2.46, 0.83, 16.1, 18.9 and 19.3 for the p.e.r., n.p.r., p.r.e., n.p.u. and b.v., respectively.The cashew nut scrap kernel meal samples I and II with protein values in the range 0.76 to 1.12, 2.86 to 3.13, 45.7 to 50.1, 41.3 to 46.7 and 48.9 to 55.3 for p.e.r. n.p.r., p.r.e., n.p.u. and b.v., respectively, were poorer compared to the good grade kernel meal with values of 2.01, 4.01, 64.2, 63.0 and 68.6 for p.e.r., n.p.r., p.r.e., n.p.u. and b.v., respectively, probably as a result of more severe heat damage.The African locust bean seed samples could not support the growth of rats, gave negative p.e.r. (−3.19 to −2.54); low n.p.u. and b.v. (19.8 to 20.9 and 22.3 to 23.7). The palm kernel meal, despite its apparent balance of amino acids showed poor protein quality indices: 1.27, 2.62, 42.0, 44.1 and 56.7 for p.e.r., n.p.r., p.r.e., n.p.u. and b.v., respectively, attributable to its high fibre content and a concomitant lowering of the digestibility.