bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of protein in yeast
Authors: Ihl Mónica , Tagle Maria Angélica
Published: November 2006

A method is described for the quantitative determination of the protein content in dried yeasts. A special pretreatment to break the yeast cell wall is used followed by a biuret determination.
Processing of pimento waste to provide a pigment source for poultry feed
Authors: Livingston A. Lyle , Knowles Richard E. , Edwards Richard H. , Kohler George O.
Published: November 2006

Fresh pimento pulp waste was dehydrated in a pilot Arnold dehydrator to give meals rich in the red xanthophylls, primarily capsanthin. Xanthophyll content of the dehydrated meal ranged from 896 to 1114 mg/kg. Dejuicing of the pimento pulp prior to dehydration decreased charring during drying as well as the quantity of water to be evaporated. Carotenoid losses during dehydration ranged from 17 to 22% for xanthophyll and 0 to 10% for carotene. Although the unprotected pimento carotenoids were rapidly lost during storage either alone or in admixture with dehydrated lucerne, addition of the antioxidant ethoxyquin proved to be very effective in preventing carotenoid storage losses. Levels of 1% pimento meal should be adequate in poultry diets when fed in combination with lucerne meal.
The tenderising effect of a muscle proteinase on beef
Authors: Penny I. F. , Voyle C. A. , Dransfield E.
Published: November 2006

Freeze‐dried beef has been reconstituted in a solution of a Ca2+ activated muscle proteinase. After storing the reconstituted meat for 5 days, the Z‐lines of the myofibrils had disintegrated and the meat, when cooked, became appreciably tender as determined by a tenderometer. Since control samples, without added proteinase, did not become as tender as the enzyme‐treated samples it was concluded that this proteinase acts as a meat tenderiser.
Trypsin inhibitor content in some varieties of soya bean (Glycine max L.) and sunflower seeds (Helianthus annuus L.)
Authors: Roy D. N. , Bhat R. V.
Published: November 2006

Some varieties of soya beans and sunflower seeds were analysed for protein, fat, moisture and trypsin inhibitory activities. The soya beans were high in protein content and all of them were equally high in trypsin inhibitory activity. Some varieties of sunflower seeds were adequate in fat and proteins, some were very low and others were reasonably free from trypsin inhibitors. Extensive cultivation of the sunflower seeds having adequate amount of fat and protein, but free from trypsin inhibitor should be encouraged.
Changes in carbohydrates during growth and development of cheena (Panicum milaceum Linn.)
Authors: Bhatia I. S. , Kaur Manoharjit , Singh Rangil
Published: November 2006

Changes in carbohydrates of cheena have been studied from the stage of maximum vegetative growth to maturity. Sucrose, glucose and fructose are the major sugars detected in both leaves and stem at all these stages of growth. Some glucofructosans are also synthesised and their number increases towards maturity of the plant. The concentrations of total water‐soluble carbohydrates, free glucose and bound fructose increase in the younger leaves and decrease in the older ones. There is a slight increase in the concentration of free‐fructose and bound glucose in the older leaves towards senescence. In the stem, the total water‐soluble carbohydrates and bound fructose increase to maximum level between the milk stage and dough stage and thereafter decline with maturity. The concentration of free glucose gradually increases in the older stem and reaches maximum value at 70‐day growth period. Cellulose content decreases beyond flowering showing again a sharp increase towards desiccation of the stem. The crude protein decreases as the plant matures and at all stages of growth the level of crude protein is higher in leaves than in the stem.
The effect of sulphur dioxide on oxidising enzyme systems in plant tissues
Authors: Haisman Derek R.
Published: November 2006

Sulphur dioxide is widely used to prevent enzymic browning, the production of off‐flavours and the destruction of ascorbic acid in peeled, sliced, crushed or otherwise mechanically damaged vegetable tissues. In some of these instances it may also prevent endogenous fermentation reactions. Probably the most important effect of sulphur dioxide is its reaction with phenolase, but there are indications that it also reacts with ascorbate oxidase, pyruvate decarboxylase and possibly other enzymes. In the inhibition of enzymic browning, sulphur dioxide appears to have a twofold action—it both inactivates the enzyme(s) which initiate the oxidation and also interrupts the subsequent reactions leading to coloured oxidation products. Unwanted side effects, such as softening of texture, resulting from the interaction of sulphur dioxide with other components of the plant tissues can often be minimised by the choice of appropriate condition.
Lipids of potato tubers. IV. Effect of growth and storage on the lipid‐degrading enzymes of the potato tuber
Authors: Berkeley Howard D. , Galliard Terence
Published: November 2006

Six varieties of potato were chosen to investigate the activity of lipolytic acyl hydrolase and lipoxygenase during tuber growth in the field, and subsequent storage at 5 ºC. Apart from an increase in the initial stages of growth, both enzymes displayed relatively consistent levels of activity throughout the life cycle of the tuber. The hydrolase showed an overall slight increase with time and there was a slight decline in lipoxygenase activity during storage. Throughout the physiological stages studied, the activities of both enzymes remained at levels characteristic for a given variety.
Temperature‐dependent cooking toughness in beef
Authors: Davey C. Lester , Gilbert Kevin V.
Published: November 2006

Toughness development in beef sternomandibularis muscle during cooking has been measured by a tenderometer, cleaving samples at right angles to the fibre direction. Since the muscles had been set in rigor mortis in an unshortened state, such toughening was not related to that induced by pre‐rigor contraction.

Two distinctly separate phases of toughening develop with increasing cooking temperature. A three‐ to fourfold toughening occurs in the first cooking phase between 40 and 50 ºC, followed by a further doubling in the second phase between 65 and 75 ºC. The first phase is associated with loss of myosin solubility, presumed to indicate denaturation in the contractile system. The second is closely associated with collagen shrinkage. This apparently induces shortening along the meat fibre, forcing out meat juice.
Composition of sweet and bitter lupin seed hulls with observations on the apparent digestibility of sweet lupin seed hulls by young rats
Authors: Bailey Raymond W. , Mills Susan E. , Hove Edwin L.
Published: November 2006

Seed hulls from both sweet and bitter varieties of lupins (Lupinus angustifolius) have been analysed for constituent polysaccharides. The hulls contained 15 to 32% oxalate‐soluble pectic polysaccharide, excluding pentose, 12 to 14% hemi‐cellulose, 44 to 51% cellulose, 0.3 to 0.4% lignin, 2.7 to 3.8% protein and 2% ash. “Crude fibre” was 54.9%. In agreement with the low lignin values all of the hemicellulose was extractable with alkali without prior delignification and 70 to 80% of the polysaccharide in depectinated hulls was hydrolysed by cellulase plus hemicellulase, likewise without delignification. Sweet lupin seed hulls, added to a complete basal diet up to 40%, did not depress growth of young rats significantly; compensatory increase in food consumption occurred. With 60% hulls in the diet growth and food efficiency were reduced. Ground hulls did depress food and protein digestibility in direct proportion to their amount in the diet, possibly because of physical entrapment in the excessive bulk in the gut. The digestibility of the “crude fibre” of the hulls was 33% when the diet contained 20% hulls; this decreased to 22% when the content of hulls in the diet was increased to 60%.
Changes in wheat lipids during mixing and resting of flour‐water doughs
Authors: Mann David L. , Morrison William R.
Published: November 2006

Lipids extracted with water‐saturated n‐butanol from flour and flour‐water doughs were examined to determine the extent of oxidations and other changes which occurred in mixing and resting dough. Extracted lipids were converted to fatty acid methyl esters (FAME) and quantified by gas‐liquid chromatography (g.l.c.) using heptadecanoic acid (17 : 0) as internal standard. The original flour or dough and the corresponding solvent‐extracted residues were acid hydrolysed, and the hydrolysate lipids converted to FAME for g.l.c. determination of the total lipid and residual unextracted lipid contents. The total flour or dough lipids equalled the extracted lipids + unextracted lipids, except where there were unavoidable autoxidative losses of linoleate (18 : 2) and linolenate (18 : 3).

The unextracted flour lipids (13% of total lipids) were not oxidised during dough mixing. There were no changes in any of the extracted lipid classes other than free fatty acids (FFA) and monoglycerides (MG) which showed losses of 18 : 2 and 18 : 3 after aerobic dough mixing. Losses of FFA and MG are attributed to lipoxygenase activity during dough mixing and the period immediately after. The small amount of 18 : 2 in the “free” petroleum ether‐extracted FFA appeared to be unaffected by lipoxygenase.

Recoveries of FFA other than 18 : 2 or 18 : 3 were constant, indicating no lipolysis of glycerolipids and no general oxidation or degradation of FFA. Experiments with [U‐14C]palmitic acid confirmed that there was no oxidation, degradation or re‐esterification of FFA.

Much of the non‐polar lipids (steryl ester, triglyceride, diglyceride, FFA, MG) and almost all of the polar lipids were bound on dough mixing. Binding was non‐selective with regard to fatty acid composition. Triglyceride was the only lipid class bound to a greater extent in anaerobic dough than in aerobic dough. Some selectivity of binding between lipid classes was indicated.
Studies on rumen metabolism. IX. Contribution of plant lipases to the release of free fatty acids in the rumen
Authors: Faruque A. J. M. Omar , Jarvis Brion D. W. , Hawke J. Clement
Published: November 2006

The role of plant lipases in the hydrolysis of dietary lipids in the rumen of pasture‐fed ruminants has been investigated by means of in vitro and in vivo experiments with rumen contents. Lipases present in the leaves of numerous pasture plants remained highly active for at least 5 h in the presence of metabolising rumen microorganisms, leading to the hydrolysis of triglyceride. Parallel experiments showed that the lipase activity of actively metabolising micro‐organisms in rumen fluid was very low. A slight increase in lipolytic activity attributable to micro‐organisms occurred after incubations of about 4 h with plant extract when the metabolic activity of the microbial population had passed its peak.

In vivo experiments showed that the lipolytic activity of rumen fluid, obtained 0.5 to 5.0 h after feeding fresh grass, was about twice that of rumen fluid obtained after overnight fasting. Paired feeding experiments showed that lipase activity was higher in rumen fluid obtained from a pasture‐fed, than from a hay‐fed animal. Nevertheless, there was appreciable activity in the rumen contents obtained from the hay‐fed twin, which is consistent with the presence of lipase activity in the extracts of dried grass.

Multiple forms of plant esterases and phosphatases were present in the soluble fraction of rumen fluid several hours after feeding.

It is concluded that the rapid release of free fatty acids which follows the ingestion of pasture is due mainly to the activity of plant enzymes and that rumen microorganisms have a subsidary role in hydrolysing ingested lipid.
The fat globule membrane in ice cream
Authors: Bird A. E. , Stainsby G.
Published: November 2006

A method for determining the average thickness of the membrane around the fat globules in homogenised ice cream mix from the mix viscosity is examined. The difficulties with this approach, such as the non‐Newtonian behaviour of the mix, the polydisperse nature of the fat globule size distribution and the contribution of the micellar casein to the volume fraction of the aqueous phase, are discussed.

Values of 60 to 90 nm for the effective “hydrodynamic” thickness have been obtained for ice cream mixes of 9% w/w vegetable fat and 10.5% w/w skim milk solids. It is suggested from these values, and from the interpretation of electron micrographs of similar mixes, that part of the micellar casein is attached to fat globules, thus increasing the effective volume fraction of the fat and accounting for the abnormally high viscosities of these mixes.
Effect of subthreshold concentrations of limonin, naringin and sweeteners on bitterness perception
Authors: Guadagni Dante G. , Maier Vincent P. , Turnbaugh Jean G.
Published: November 2006

A sensory panel of experienced judges was used to determine taste thresholds of mixtures of limonin and naringin and various sweeteners. Data from these experiments showed that within the 95% confidence interval, subthreshold interactions between limonin and naringin were additive, indicating that less than threshold amounts of these compounds contributed to bitterness of a mixture. Mixtures of hesperetin dihydrochalcone glucoside (HDG), neohesperidin dihydrochalcone (NHD), naringin dihydrochalcone (ND), sucrose and naringin were neither additive nor synergistic at subthreshold concentrations. At suprathreshold levels, sucrose, (HDG) and (NHD) were effective in suppressing naringin bitterness, but (ND) was not.
Quantitative determination of fusel alcohols in beer and fermenting wort
Authors: Chen Ernest C.‐H. , David Jean J.
Published: November 2006

A simple quantitative method for determining four aliphatic fusel alcohols in beer and fermenting wort, namely n‐propanol, isobutanol, 2‐methyl‐1‐butanol and 3‐methyl‐1‐butanol, has been developed. Samples were distilled at reduced pressure (10 Torr) and analysed by gas liquid‐solid chromatography. Graphitised carbon black deactivated with 0.3% SP‐1000 Carbowax 20 M modified with derivative of terephthalic acid and 0.3% phosphoric acid was used as column packing. Coefficients of variation determined were 3% or less. To serve as examples, contents of fusel alcohols in some commercial and experimental beers and a wort fermented for various lengths of time are reported.
The occurrence of volatile amines in uncured and cured pork meat and their possible role in nitrosamine formation in bacon
Authors: Patterson R. L. S. , Mottram D. S.
Published: November 2006

The concentrations of volatile amines were determined in the eye muscle of 10 pork carcasses at the following stages of curing: immediately after slaughter, before curing, after maturation and after vacuum‐packed storage of the bacon.

Methylamine (MA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA), n‐propylamine (n‐PA) and isopropylamine (iso‐PA) were detected by gas chromatography; MA was present in greatest concentration [up to 1900 μg/kg (1 part/109)], the concentration of the others being considerably less.

During the course of bacon manufacture, the concentrations of DMA, TMA, n‐PA and iso‐PA increased consistently up to the end of the maturation period, despite the presence of nitrite both in the brine and in the bacon; in subsequent storage, only DMA and TMA continued to increase. MA decreased during curing and maturation, and thereafter remained unchanged; EA and DEA were unchanged throughout at very low levels. The mean value for the concentration of DMA was below 200 μg/kg before curing; higher values (maximum 520 μg/kg) were found in vacuum packed stored bacon.

No nitrosamines were found above the detection limit (1 μg/kg) in any of the uncooked pork or bacon.
An approach to the chemical analysis of folic acid: Gas chromatography of a degradation product from synthetic folic acid samples
Authors: Seifert R. M.
Published: November 2006

A new chemical approach to the assay of synthetic folic acid has been investigated. Folic acid is cleaved with bisulphite to give a pteridine fraction and p‐amino‐benzoylglutamic acid. Acid hydrolysis and subsequent esterification converted the aromatic amine to ethyl p‐aminobenzoate. This ester, when analysed by gas chromatography (g.l.c.), gave consistent yields averaging 49% from 50 to 1000 μg of folic acid. The recovery being predictable, the percentage yield can be used as a correction factor for unknown samples. The present procedure can be used for synthetic folic acid.
Formation of dimethyl sulphide from S‐methylmethionine in onion seedlings (Allium cepa)
Authors: Hattula Tapani , Granroth Bengt
Published: November 2006

Homogenates of onion seedlings catalyse the decomposition of S‐methyl‐methionine into dimethyl sulphide and homoserine. The reaction is rather slow and seems not to be of primary importance in onion flavour formation or S‐methylmethionine metabolism. Extracts of scarlet runner bean seedlings are also active, whereas dormant onion bulb and other seedlings tested showed no or very low activity.
Varietal relationships of the α‐gliadin proteins in wheat
Authors: Platt Steven G. , Kasarda Donald D. , Qualset Calvin O.
Published: November 2006

The aggregatable α‐gliadin of Bernardin et al.1 was found in only 4 of 16 wheat varieties tested by ultracentrifugation of an acetic acid extract combined with examination of the pellet by gel electrophoresis at pH 3.3. Those 4 wheat varieties were Scout 66, Cheyenne, Ponca and Itana. The name A‐gliadin was given to the aggregatable α‐gliadin to distinguish it from other gliadins with similar electrophoretic mobilities. The two‐band gel electrophoretic pattern at pH 3.2 was the same for A‐gliadin from all four varieties as was the pattern at pH 8.6. The molecular weight of A‐gliadin from all four varieties was about 36 000 as determined by gel electrophoresis in an SDS (sodium dodecyl sulphate) buffer. The genes responsible for the A‐gliadin components apparently were contributed by Crimean (Turkey) which appeared in the ancestry of all four varieties.
Effect of dietary variation, with respect to energy and crude protein levels, on the oxidative rancidity exhibited by frozen porcine muscles
Authors: Owen John E. , Lawrie Ralston A. , Hardy Brian
Published: November 2006

The phenomenon of oxidative rancidity exhibited by porcine muscle tissue when held under conditions of frozen storage is influenced by a number of factors. These factors determine the variability exhibited by different muscles with respect to oxidative rancidity. One such factor which is intimately concerned with the above phenomenon is the level of constituent polyunsaturated fatty acids of the intramuscular lipids. In the case of the intramuscular triglyceride fraction, the level of constituent polyunsaturated fatty acids can be modified by dietary means. An experiment is described in which the effect of different diets on the tendency of minced frozen porcine muscle to undergo oxidation was investigated. The particular diets used varied in energy and protein levels and were typical of the kinds of diets used to improve the growth rates and commercial carcase quality of pigs.

The results obtained indicated that the particular diets used had little effect on the fatty acid content of the porcine muscle triglycerides and none on that of the phospholipids. It was in the latter fraction that oxidation was mainly exhibited. The major factor influencing the susceptibility of minced frozen porcine muscle to undergo oxidative rancidity, within the dietary limits of the experiment described, was found to be the ultimate (24 h post mortem) pH level of the muscle concerned.
Influence of ascorbic acid and ph on the formation of n‐nitrosodimethylamine in cured pork containing added dimethylamine
Authors: Mottram Donald S. , Patterson Ronald L. S. , Rhodes Douglas N. , Gough Terence A.
Published: November 2006

Under laboratory conditions simulating normal bacon curing, the conversion to N‐nitrosodimethylamine (NDMA) of dimethylamine (DMA) added to pork, was 0.1%. Addition of sodium ascorbate to the brine was shown to suppress NDMA formation from added DMA in this simulated curing system and in experimental curing of pork middles spiked with DMA. Heating, by canning or frying, resulted in the formation of small amounts of NDMA in the lean and considerably higher concentrations in the fried fat. However, the lowest amounts of NDMA were found in the bacon cured in the presence of ascorbate.
Preparation of low‐gossypol cottonseed flour
Authors: Damaty Sayed M. , Hudson Bertram J. F.
Published: November 2006

A new laboratory process has been developed for the production of fat‐free cottonseed flour with a very low content of both free and bound gossypol. The process depends on the successive extraction of flaked cottonseed meats with (1) hexane and (2) aqueous acetone, followed by anhydrous acetone. The cottonseed flour so derived, with a total gossypol content of about 0.1%and a protein content around 63%is considered appropriate for use in human food.
Relationship between composition and physical properties of a three‐component sugar system
Authors: Mynott Alan R. , Higgs Stuart J. , Jowitt Ronald
Published: November 2006

The relationship between composition and certain physical properties of water‐sucrose‐invert sugar solutions have been determined and means whereby the composition of any such solution may be derived from its refractive index and optical rotation are proposed.
Effects of variation of heat treatment conditions on the nutritional value of low‐Glucosinolate Rapeseed Meal
Authors: Josefsson Egon
Published: November 2006

The nutritional value of rapeseed meal, prepared from the low‐glucosinolate cultivar Bronowski, as affected by heat treatments of the seed at various temperatures and times and at various moisture contents was evaluated by feeding experiments with mice. The optimum temperature and time intervals appeared to be 100–1100 C and 15–60 min, respectively, at a moisture content of 8%.
Microbiological screening of the straight chain fatty acids (c1‐c12) as potential silage additives
Authors: Woolford Michael K.
Published: November 2006

A microbiological screening procedure was used to assess the potential of each of the straight chain members of the series of fatty acids, formic to lauric inclusive, as silage additives. Thirty‐four pure cultures of microorganisms were subjected to serial dilutions of each of the acids in broth buffered at unit pH intervals between 3 and 6 inclusive. All the fatty acids of the series appeared to have potential; the lower members (C1‐C7) prevented the growth of spore‐bearing bacteria and the higher acids had more general antimicrobial effects. A consistent feature of the data obtained was the increase in antimicrobial activity with a decline in pH.
Microbiological screening of food preservatives, cold sterilants and specific antimicrobial agents as potential Silage Additives
Authors: Woolford Michael K.
Published: November 2006

Some food preservatives, cold sterilants and specific antimicrobial agents were tested against a range of microorganisms at pH 3, 4, 5 and 6 in a semi‐micro assay. The antimicrobial spectra obtained indicated that several of the components might be useful as silage additives. Lactic acid appears to have potential but only when the feed is kept anaerobic as it affords no protection against the activities of yeasts and moulds. Potassium sorbate might have wider application for increasing the aerobic stability of silage, whilst sodium nitrite appears to have application for restricting or suppressing fermentation in silage. The use of sodium benzoate is unlikely to be economic. Formaldehyde and paraformaldehyde would appear to have great potential in the production of non‐fermented silage, whereas the relatively high quantities of hexamine and propylene oxide which are required make these chemicals unattractive. The antibiotic pimaricin appears to have potential as an agent for preventing aerobic degradation of silage and the synthetic antimicrobial agent Bronopol for preventing the activity of sporebearing bacteria. Although it appears that tylosin could be used to prevent bacterial growth the quantity required is, for an antibiotic, quite large.
The action of cold alkali on bone collagen
Authors: Grand Roger J. A. , Stainsby George
Published: November 2006

Solubilised collagen has been prepared from ossein by the action of 2 N NaOH at a variety of temperatures. Measurements of intrinsic viscosity and N‐terminal amino acids have been used to estimate the extent of hydrolysis during pretreatment. The properties of gelatins prepared from the collagen have also been examined. The optimum conditions involve a pretreatment time of approximately one week and a temperature of 10–12 °C. Under these conditions the cold alkali is highly selective for intermolecular bonds rather than for peptide bonds.
Lipid composition of five species of Indian prawns
Authors: Gopakumar K. , Nair M. Rajendranathan
Published: November 2006

The lipid and fatty acid compositions of five Indian species of prawns, Metapenaeus monoceros, M. dobsoni, M. affinis, Penaeus indicus and Parapenaeopsis stylifera, were examined. Phospholipids constituted 50–70% of the total lipids, with phosphatidyl choline (50%) and phosphatidyl ethanolamine (29%) as their chief components. Unsaponifiable matter comprised 21–40%, chiefly cholesterol: triglycerides only constituted 9–14.5%. In the total lipids (I.V. 90–112), saturated, monoenoic and polyenoic fatty acids averaged 42, 24 and 34%. Palmitic acid is high, oleic low, and 20:5 generally, but not always, higher than 22:6. The only brackish water prawn, M. monoceros, though generally in conformity, was distinctive in several respects.
Fatty acid composition of grain from winter and spring sown oats, barley and wheat
Authors: Welch Robert W.
Published: November 2006

The fatty acid composition of grain has been studied in six varieties of oats, two of wheat and two of barley, sown in pots in an unheated glasshouse in winter and in spring. Differences were found between the species in composition and in their response to sowing date. Oats showed the greatest varietal variation in both total fatty acid (TFA) content and in the proportion of its component fatty acids. The content and degree of unsaturation of the oat TFA was higher in the winter sown than in the spring sown crop. Increases in the TFA content of oats, whether arising from differences in variety or sowing date, were generally followed by an increase in the proportion of oleic acid and a decrease in the proportions of palmitic and linoleic acid in the TFA. Winter sowing, as compared with spring, led to a small, but significant, decrease in the TFA content of barley and an increase in its degree of unsaturation. There were no significant changes in the content or composition of wheat TFA as a result of differences in sowing date. Factors influencing the differences in TFA content and composition between species, varieties and sowing dates are discussed.
Distribution of flavour components in onion (Allium cepa L.), leek (Allium porrum) and garlic (Allium sativum)
Authors: Freeman George G.
Published: November 2006

Dry bulb onions and leeks, at the marketable stage of development, were dissected into nine and ten fractions respectively, comprising the stem and leaves in succession from the oldest outer layers. Each fraction was separately analysed for flavour components by determination of thiosulphinate and pyruvate. Similarly, garlic cloves were divided into five fractions. There was a consistent pattern of flavour distribution in the seven onion varieties studied. The dried outer scales were virtually free from flavour components, the concentrations of which (on a fresh weight basis) increased progressively from a minimum value in the outer leaf to the innermost tissue and the stem. The latter often contained more than twice the concentration present in the outer leaf. The pattern in the roots and edible portions of leek differed in detail from that in onion. Flavour intensity increased progressively from the outer leaf to the inner tissues and the concentrations in both the roots and the stem were approximately equivalent to that of the fourth leaf numbered from the outer leaf. The pattern of flavour distribution in garlic cloves was simpler than that of onion and leek. The storage leaf accounted for the bulk of the weight of the clove as well as its flavour content. Some aspects of knowledge of the metabolism of inorganic nitrogen and sulphur compounds in roots and other tissues and transport of the corresponding metabolites have been briefly reviewed as the basis of a preliminary interpretation of the above observations. Attention has been drawn to the bearing of the results on preparation of onion for cooking and processing and on sampling for analysis.
Texture of cooked potatoes: The effect of ions and ph on the compressive strength of cooked potatoes
Authors: Hughes J. Carey , Grant Alex , Faulks Richard M.
Published: November 2006

It was shown from experiments on disks cooked in solutions of calcium chloride and calcium acetate, and in buffered solutions of calcium chloride at various pHs (sodium concentration constant) and from experiments where the ratios of disks to calcium chloride were varied, that the effect of calcium in increasing the compressive strength of the disks was small compared to the effect of reduced pH. The interaction of sodium and calcium was investigated at pH 6 (≈︁ the pH of cooked potato tissue). The effect of sodium in reducing compressive strength of the disks outweighed the effect of calcium in increasing compressive strength. Sodium and potassium chloride had a similar effect on loss of compressive strength on cooking. Increased compressive strength due to pH or the presence of calcium was overcome by extending the length of cooking. It is suggested that transelimination, ion exchange and hydrogen bond breakage may be more important factors than the chelation of calcium by naturally occurring phytin, in the breakdown of pectic substances and loss of intercellular adhesion during normal cooking of toes.
A chemical and biological assessment of Aspergillus oryzae and other filamentous fungi as protein sources for simple stomached animals
Authors: Smith Ronald H. , Palmer Robert , Reade Austin E.
Published: November 2006

A. oryzae had previously been selected as an organism suitable for a proposed farm fermentation system designed to improve the protein content of barley grain. Amino acid analyses and measurements of protein nutritive values in rats and pigs were carried out with A. oryzae grown on barley grain and potato substrates. For comparison, Fusarium semitectum, Trichoderma viride, Gliocladium deliquescens, Rhizopus arrhizus and a different strain of A. oryzae were also evaluated. There were small variations in the content of essential amino acids between the organisms studied. When referred to the requirements of the growing rat or pig, all species were deficient in the S‐amino acids which were generally the first limiting acids. In experiments with rats, the fungi gave net protein utilisation (NPU) values in the range 34 to 44; and true digestibilities ranged from 69 to 83%. Supplementation with L‐methionine gave a somewhat varied response with marked increases in NPU with some fungi (e.g. F. semitectum). In experiments with pigs, supplementation of A. oryzae with DL‐methionine did not give the expected increase in NPU and with one preparation (A. oryzae grown on barley) there was an apparent depression in NPU. The reason for this anomalous behaviour is not clear; and because under these experimental conditions F. semitectum behaved more predictably, it is suggested that nutritionally it is better suited to the farm process than A. oryzae. Non‐α‐amino N in the form of chitin (plus chitosan), nucleic acids and nucleotides accounted for between about 10 and 20% of the total N of the mycelia of these organisms.
Phosphate sorption isotherms for some Sierra Leone soils
Authors: Rhodes Edward R.
Published: November 2006

Phosphate sorption isotherms were obtained for three acid highly weathered soils of Sierra Leone, by equilibrating air dry samples for 24 h with 0.01 M KH2PO4 solution at 25 °C. The Langmuir and Temkin equations were used to evaluate the sorption capacities for phosphate. Phosphate sorption maxima of 2439, 2137 and 1429 mg/kg soil and x/log c of 774, 718 and 610 were calculated; where x=phosphate sorbed (mg/kg soil) and c=equilibrium phosphate concentration (μmol dm−3). Qualitative relationships between these sorption parameters and other soil variables are shown.
The effect of some additives on aerobic deterioration of silages
Authors: Ohyama Yoshinobu , McDonald Peter
Published: November 2006

Two experiments are described. In the first, formic acid was applied alone and in combination with isovaleric, caproic or lauric acid to wilted herbage prior to ensiling. The effects of these treatments on the deterioration of silages on exposure to air over a 7 day period were measured. Temperature increase, chemical and microbiological changes were determined. Silages treated with formic acid alone deteriorated, while the untreated control silages were relatively stable. The formic acid treated silages containing either isovaleric or caproic acid remained stable over the 7 day aerobic period. In the second experiment, in addition to the previous treatments, formaldehyde was also included in place of formic acid. In this case, only the untreated control silages deteriorated markedly over the 7 day period.
Pollution of vineyards by atmospheric lead
Authors: Favretto Luciano , Marletta Giuliana Pertoldi , Gabrielli Luciana Favretto
Published: November 2006

Lead accumulation in vineyards exposed to automobile exhaust gases has been studied by means of three indicator materials (grapes, leaves and soil) sampled at increasing distance from the source. The regression analysis of concentration data on the logarithm of the distance, based on an accepted model, shows that these three materials are suitable for detecting the extent of pollution. Far from the source, where the polluting effect is negligible, the mean typical levels of lead in these materials are 0.43, 6.7 and 16.2 μg/g dry weight respectively. The contribution of the atmospheric lead to the pollution of plant materials, at various distances from the source, is thus simply evaluated. The surface contamination for grapes and leaves is also discussed.
The energy costs of the nitrogen fertilisers used in Britain, the returns received and some savings that are possible
Authors: Cooke George W.
Published: November 2006

Published estimates suggest that one‐third of the energy used in many intensive mechanised systems of arable agriculture is required to produce the nitrogen fertilisers used. The increases in yield that nitrogen fertilisers give in Britain are very profitable to farmers although prices of N are nearly twice those of two years ago. Some of the nitrogen involved in intensive agricultural systems is lost. Losses of nitrate by leaching can be diminished by greater care in timing the application of nitrogen fertilisers. Denitrification, which results in loss of nitrogen and its oxides, is diminished by careful management of soil and crop wastes. Losses of ammonia may be lessened by better handling of organic manures. Nevertheless some loss of nitrate by leaching in winter is inevitable, as is loss of ammonia from animal excreta. Farmers can use fertilisers more efficiently by fitting the amounts applied more closely to local conditions of soil, previous cropping and manuring and to the weather. Increased use of leguminous crops and more efficient use of organic manures will diminish the need for nitrogen. But it is not possible to achieve large yields of non‐leguminous crops by relying solely on nitrogen from “natural” sources; fertilisers are essential in modern intensive agriculture.
The interfacial factor in the heat‐induced conversion of chlorophyll to pheophytin in green leaves
Authors: Haisman Derek R. , Clarke Michael W.
Published: November 2006

The rates of the conversion of chlorophyll to pheophytin in the green leaves of common vegetables and other plants at different temperatures in buffered electrolyte systems were studied. Kinetic measurements showed that the conversion only occurred above a threshold temperature of 50–60 °C and was most probably a pseudo‐first order reaction. Rates were found to be proportional to √[H+]. The dependence of the rate of conversion upon species, temperature and electrolyte type can be explained on the basis of a heat‐induced metamorphosis of the chloroplasts to a smectic mesophase which occludes the chlorophyll. The rate of the reaction then depends on the transfer of hydronium ions across the interface and can be largely controlled by modifying the interfacial potential.
A comparison of organoarsenic compounds from different marine organisms
Authors: Lunde Gulbrand
Published: November 2006

Organic bound arsenic is enriched in aqueous extracts prepared from marine raw materials. The extracts have been chromatographed in four different thin‐layer chromatographic (t.l.c.) systems. All extracts prepared by boiling and enzymic hydrolysis of heat treated and fresh raw material contain one major organo‐arsenic compound with the same t.l.c. behaviour in all systems. Aqueous extracts prepared from oil from seaweed and from fish and treated with constant boiling hydrochloric acid also contain one compound with identical behaviour in all t.l.c. systems. The chromatographic behaviour of the latter organoarsenic compound is, however, different from that of the organoarsenic compound in the aqueousract.
A modified method for the estimation of bound formaldehyde in treated feed proteins
Authors: Van Dooren Paul H.
Published: November 2006

Methods for determining bound formaldehyde in treated feed proteins are reviewed and a modified two‐step distillation procedure is described. A critical study is made of the various parameters concerned with the adopted chromotropic acid–H2SO4–HCHO reaction used in the analysis. The most favourable conditions necessary for optimal recovery, precision and accuracy are discussed.
A spectrofluorimetric assay of the tryptophan content of feedstuffs
Authors: Buttery Peter J. , Soar John B.
Published: November 2006

A method for the analysis of the tryptophan content of feedstuffs employing sodium hydroxide hydrolysis followed by the spectrofluorimetric estimation of tryptophan is described. Provided the development of the fluorophore is carried out in the absence of light, satisfactory results for a wide range of feedstuffs are obtained.
Exposure of meat to methyl bromide during refrigerated‐store pest control; residues in beef and lamb and effect on quality
Authors: Rhodes Douglas N. , Patterson Ronald L. S. , Puckey David J. , Heuser Stanley G. , Wainman Harold E. , Chakrabarti Biswajit , Allan Edric N. W.
Published: November 2006

Beef and lamb were exposed to methyl bromide in a refrigerated container during trial fumigations at 1, 3 and 10 times the level considered necessary for rodent control in cold‐store insulation material. Traces of residual methyl bromide were detected by GC‐MS in fats after periods of up to 3 months in refrigerated storage and some effect on taste and odour after roasting was noted in beef subjected to the highest treatment level.
The digestion of the lipids of processed red clover herbage by sheep
Authors: Outen George E. , Beever David E. , Osbourn Dennis F. , Thomson David J.
Published: November 2006

Three mature wether sheep, equipped with re‐entrant cannulae at the proximal duodenum and terminal ileum were fed either frozen, or dried and chopped or dried and ground red clover herbage, and samples of duodenal and ileal digesta and faeces were collected. Analysis of the feed and digesta samples for their individual long chain fatty acid content enabled the quantitative digestion of herbage lipids to be investigated.

The flow of total fatty acids into the small intestine was greater than the amount daily consumed when the dried diets were fed, whilst on the frozen diet there was a net loss between mouth and duodenum (P<0.01). There was a marked increase in the proportion of saturated fatty acids in the fatty acid fraction collected at the duodenum relative to the feed on all diets, but some dietary differences were noted. The extent of hydrogenation was reduced on the ground diet and, to a lesser degree, on the chopped diet. Consequently these diets had significantly higher proportions of C18:1 in the duodenal fatty acid fraction than the frozen diet (ground, 22.5%; chopped 17.0, frozen 13.5;P<0.01). These changes influenced the quantity and composition of the fatty acid fraction absorbed from the small intestine; the ratio of unsaturated to saturated fatty acids absorbed (ground, 0.47; chopped, 0.32; frozen, 0.24) being significantly greater on the ground diet (P<0.01).
Changes in cell‐wall carbohydrates and lignin of some forage‐type millets as affected by growth stage
Authors: Singh I. S. Bhatia Rangil , Dogra K. K. , Dua Saroj
Published: November 2006

Changes in the cell‐wall carbohydrates and lignin of bajra (Pennisetum typhoides), jowar (Sorghum vulgare) and napier (Pennisetum purpureum)–bajra hybrids (NB21) as affected by growth stage are reported. With growth of the plants the concentrations of α‐cellulose and hemicellulose increased in the stems. In bajra and jowar this increase was gradual up to 60–70 days growth stage followed by a decline and a subsequent rise towards maturity. In contrast, in NB21, α‐cellulose continued to rise gradually throughout the growth period. The concentration of hemicellulose was much higher in the stems than in the leaves of NB21. With the ageing of the plants the lignin content increased in all these forage crops. In NB21 the stems contained more lignin than the leaves at all stages of maturity. Fluctuations in the contents of lignin, cellulose and hemicellulose followed similar trends indicating that possibly they are components of a common matrix in the cell wall. In NB21 the water‐soluble carbohydrates continued to rise throughout the growth period unlike other forage crops. The protein content decreased as the NB21 plants matured. The protein content of the leaves of these plants was always higher than that of the stems. The oxalates gradually declined with the maturation of the plants.
Effects of spray‐drying and freezing on the proteins of liquid whole egg
Authors: Parkinson T. Lawrence
Published: November 2006

Commercial pasteurised liquid whole egg was spray‐dried, both alone and mixed with liquid milk, and some of it was frozen. Paper electrophoresis revealed that lipoprotein fractions from the pasteurised liquid egg were mainly immobile, in contrast to unpasteurised new‐laid egg which contained both mobile and immobile lipoprotein fractions. The major difference between the soluble proteins of the commercial chilled pasteurised liquid egg and those of the same egg after freezing and thawing was the presence, in the former, of an inert lipoprotein fraction, amounting to 3.6% of the total egg solids and containing 88% lipid. The “soluble” proteins of spray‐dried egg and egg‐milk mixture also included large “inert” lipoprotein fractions eluted with the void volume. They contained 72–81% of lipid and accounted for 7–13% of the total egg solids. Larger fractions were eluted by the stronger salt buffer solutions and by hydrochloric acid from the dried egg‐milk mixture than from the dried egg, and these were probably derived from the milk. All the spray‐dried samples possessed the “inert insoluble” protein fraction characteristic of liquid egg, and the presence of a high molecular weight lipoprotein fraction was confirmed in each case. The “insoluble proteins” of the spray‐dried samples had higher protein contents than those from the original chilled liquid egg and the thawed frozen egg.
Relationship between chemical composition and breakdown in cooked potato tissue
Authors: Warren Donald S. , Woodman John S. , Gray David
Published: November 2006

The effects of variety, harvest date and plant population on breakdown are considered in the light of two current theories relating chemical composition to the texture of cooked potato tubers. Differences between cell surface area could not account for the differences in breakdown found. The results also show the inadequacy of the theory ascribing a primary role in texture control to the “swelling pressure” generated by starch on gelatinisation. It seems likely that breakdown of cooked potato tubers is due to excessive hydration of cell wall material. On this theory high levels of polyuronides and phytate and low levels of polyvalent metals in the cell wall material favour breakdown. Correlation analysis indicates that other chemical factors which have yet to be identified may also play a role in the control of cooked potato texture.
Release of bound iron and aluminium from soils by the root exudates of tea (camellia sinensis) plants
Authors: Jayman T. C. Zaman , Sivasubramaniam Sinnathurai
Published: November 2006

Root exudate of young tea plants contained appreciable quantities of malic acid. Malic acid was capable of solubilising P, Fe and Al from rock phosphate fertiliser. Tea soils incubated with added malic acid released appreciable quantities of P, Fe and Al. In tea soils where most of the P added as the rock phosphate is immobilised as the iron and aluminium phosphates, malic acid may prove to be useful in chelating these elements and so releasing the phosphates for utilisation by the tea plant.
A comparison of the use of conventional and semipurified diets of high and low linoleate content on the responses of laying hens to dietary linoleic acid
Authors: Balnave Derick
Published: November 2006

Pullets given a semi‐purified, low‐linoleate (SPLL) diet from 15–40 weeks of age produced significantly larger eggs but had significantly smaller body weights at 40 weeks than birds fed conventional diets to this age. When semi‐purified diets were fed from 40 weeks subsequent body weight gain was significantly greater in birds previously fed the semi‐purified diet. The minimum increase in mean egg weight between 40–68 weeks was observed in pullets fed from 15 weeks on the SPLL diet and given restricted amounts of food from 40 weeks. This poor egg weight increase was offset by ad libitum feeding, by feeding a conventional diet between 15–40 weeks or by feeding a semi‐purified, high‐linoleate, maize oil‐supplemented diet at similar ME intakes from 40–68 weeks. However, the actual mean egg weights at 68 weeks of restricted or ad libitum fed birds given the SPLL diet from 15 weeks were little different to those of birds on equivalent feeding regimens and consuming greater amounts of linoleic acid.
Methyl‐S‐methionine sulphonium salt: A precursor of dimethyl sulphide in cacao
Authors: Lopez Alexander S. , Quesnel Victor C.
Published: November 2006

Chromatographic evidence is presented to show that a methyl‐S‐methionine sulphonium salt is present in fermented and dried cacao. It is extremely labile and readily decomposes to dimethyl sulphide which contributes to chocolate aroma.