bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes undergone by free amino‐acids during the manufacture of black tea
Authors: Roberts G. R. , Sanderson G. W.
Published: November 2006

(1) An increase in total free amino‐acids during the withering stage of tea manufacture was confirmed, and was found to be dependent on storage conditions which promote the onset of senescence in plucked tea shoot tips (especially desiccation). The rate of increase was positively related to temperature up to the point where the tissues were killed, after which no further changes took place. Individually, all the major amino‐acids increase during withering except the most abundant amino‐acid, theanine, which shows an appreciable decrease.

(2) During the fermentation stage of black tea manufacture the concentrations of leucine, isoleucine, serine, glutamic acid, glutamine, threonine and phenylalanine are appreciably reduced. Other free amino‐acids undergo little change in concentration.

(3) During the drying stage of tea manufacture there is a small general decrease in free amino‐acid concentration.

(4) There is an active metabolism of free amino‐acids in plucked tea shoot tips. Within 3 h of feeding glycine‐14C, radioactivity could be detected in all the free amino‐acids and especially in serine which contained about ten times as much 14C as did glycine after this period. Caffeine increased in concentration and in degree of labelling with time from feeding of glycine‐14C which suggests that the amino‐acids are the precursors of this purine compound in tea shoot tips.

(5) The effect of these changes on the organoleptic properties of black tea are discussed.
The chemistry of the natural tenderisation or maturation of meat
Authors: Clayson D. H. F. , Beesley J. A. , Blood Ruth M.
Published: November 2006

It is deduced that meat will be tender when cooked if the connective tissue, including the endomysium, undergoes such a change during maturation, or during the earlier stages of cooking, that on moderate heating it breaks during or before contraction. It seems improbable that this change is a direct effect of enzyme action. Studies with isolated collagenous membranes have shown that they are weakened by some oxidation products of hydroxylamine and that the effect is enhanced by the presence of lactate, acetate or succinate. No direct evidence of the formation of hydroxylamine or derivatives thereof in meat could be obtained. The difficulties surrounding the detection of the weakening agent in the low concentrations that could be significant in meat maturation processes, are discussed.
Studies on rumen metabolism. V.—formation of branched long chain fatty acids in cultures of rumen bacteria
Authors: Tweedie J. W. , Rumsby M. G. , Hawke J. C.
Published: November 2006

When mixed rumen bacteria were incubated with isobutyrate‐1‐14C, the 14C‐label was incorporated into branched long chain fatty acids with both odd and even numbers of carbon atoms.

Tracer studies showed that the 14C‐label from DL‐valine‐4‐14C was incorporated into branched long chain fatty acids and also into straight chain fatty acids with odd numbers of carbon atoms. In addition, labelled isobutyrate and propionate were synthesised from valine and probably represent intermediates in the synthesis of the branched and straight chain fatty acids respectively.
Effects of temperature on post‐mortem metabolism in beef muscle
Authors: Cassens R. G. , Newbold R. P.
Published: November 2006

Changes in pH and in the levels of some phosphate fractions with time were examined in beef muscle stored at 1°, 15° and 37° soon after slaughter. At 15° the fall in pH of the muscle and decreases in concentration of creatine phosphate and of other acid‐labile phosphate occurred more slowly than at 37° and there was also a slower increase in the concentration of inorganic phosphate. Not all of these changes occurred more slowly at 1° than at 15°, however. The alkali‐labile phosphate concentration remained virtually constant at 37° but increased at each of the other two temperatures, the increase at 1° being greater than that at 15°. These changes in alkali‐labile phosphate concentration were attributable to the accumulation of hexose‐6‐phosphate. An effect of temperature on the metabolism of an organic phosphate fraction stable to both acid and alkali was noted.
The buffering constituents of herbage and of silage
Authors: Playne M. J. , McDonald P.
Published: November 2006

The buffering capacity values of several herbage species and of silage made from this herbage, and the contributions of plant constituents to this buffering, between pH 4 and 6, were determined, and found to vary with the herbage species; values in the silages were normally two to three times greater than those in the plant materials. The anion fraction of the plant materials accounted for 68–80% of the total buffering capacity, and for 73–88% in the silages. Buffering caused by plant proteins was estimated to be 10–20% of the total buffering capacity.

The buffering capacity of wilted red clover (Trifolium pratense) was 18% lower than that of fresh red clover, and the total organic acid content of wilted clover was also lower than that in fresh clover.

The organic acids were responsible for most of the buffering effect in herbages and silages. In Italian ryegrass (Lolium multiflorum), the main buffers were malate and citrate, but, in red clover, glycerate and malate were the main buffers. The clovers studied contained a high level of glycerate (4% of dry matter). During ensilage, malate, citrate and glycerate were extensively broken down. The increased buffering capacity during ensilage was caused mainly by the formation of lactates and acetates.
Cereal proteins: Immunological studies
Authors: Ewart J. A. D.
Published: November 2006

A rabbit antiserum to Wichita gliadin has been used to study cereal proteins by the double diffusion technique. Wheat flours give strong reactions, at least five antigens being common to the eight varieties tested, but the number may exceed nine. Rye flour shows a closely similar antigenic reaction to that of wheat, but barley appears to contain only three wheat antigens, two of these being in trace quantities. Oat and maize do not react to any significant extent. Gliadins of four wheats reveal at least six confluent lines, and the glutenins produce four, which give reactions of identity with gliadins. Fractionation of glutenin on Sephadex, however, indicates that only the minor, soluble, part of glutenin, containing traces of gliadins and components of low electrophoretic mobility, is responsible for the main glutenin reaction. The bulk of the glutenin is insoluble and so not amenable to double diffusion techniques, but nevertheless evidence has been produced that this material may contain one or more polypeptide chains which have certain antigenic (and therefore structural) features in common with one, or possibly two, gliadin proteins.
Estimation of protein in dried herbages using the dyestuff orange G
Authors: Outen C. E. , Tilley J. M. A. , Wilson R. F.
Published: November 2006

The uptake of the dyesluff Orange G by herbage samples is linearly proportional to their nitrogen content; the errors can be attributed in part to differences in the proportion of the nitrogen which is water‐soluble. The method is not as precise as a Kjeldahl analysis and seems suitable only as a simple and cheap technique to determine an approximate crude protein content or perhaps for the analysis of ‘true’ (hot‐water insoluble) protein content.
The treatment of meats with ionising radiations. XIII.—Pasteurisation of beef and lamb
Authors: Rhodes D. N. , Shepherd H. J.
Published: November 2006

The maximum dose of γ‐radiation that can be applied to beef or lamb at 32°F in the absence of air, without causing changes in organoleptic qualities detectable by a trained taste panel, was found to be 0·4 Mrad. The effect of this dose on the microbial flora and the storage stability of beef in joints, and lamb in joints and halves, has been investigated. The results are discussed in relation to the possibility of transporting meat from overseas and the preservation of prepacked meats for retail distribution.
The mineral composition of brussels sprouts
Authors: Haworth F. , Cleaver T. J.
Published: November 2006

The distribution of N, Ca, K, Mg and P in Brussels sprout plants has been studied. The calcium content of sprout buttons was very low relative to that in the rest of the plant but, from the analysis of buttons from plants grown on calcareous soils, this low calcium content appeared to be a normal condition and no reason was found to connect low calcium content with ‘internal browning’.

The mineral composition of sprout buttons varied much less from position to position on the plant than did the composition of the laminae and the petioles. Laminae of old leaves contained high percentages of Ca, K and Mg. The pattern of distribution of K in the laminae at different positions on the plant was not the same in the plants grown at two sites, and this might be explained by differences in potash status of the two soils.

The manurial treatments had larger positional effects on the Ca and N contents of the sprout buttons and of the laminae than for the petioles. The supply of N, whether as fertiliser or farmyard manure, had a greater effect on the mineral composition of both sprout buttons and laminae than had applications of phosphatic or potassic fertilisers.
Residues of supona in sheep
Authors: Robinson J. , Malone J. C. , Bush B.
Published: November 2006

Supona is a new organophosphorus compound which is highly effective for the control of maggot fly strike in sheep.

Tissue samples taken from sheep which had been treated with various concentrations of Supona have been analysed for residues of Supona and the lipophilic metabolite trichloroacetophenone.

As a result of treatment of sheep with concentrations of Supona at and above the intended field usage rate the following conclusions were drawn:

The Supona residues in the fat depots of sheep killed 7 days after dipping in double‐strength dip wash never exceeded 0·1 ppm Supona and were in the main substantially below this level.

The residues in the major organs of these sheep were below the minimum detectable amount (0·003 ppm).

The residues of trichloroacetophenone in the body fats and organs of sheep treated with Supona were below the minimum detectable amount (0·001 ppm).

The residues of Supona in the body fat of sheep dipped in normal strength Supona dipwash and killed 3 days after treatment were less than 0·05 ppm.

The residues of Supona were considerably lower and much less persistent than those occurring with dieldrin when used at comparable concentrations.
Decomposition of L‐malic acid by wine yeasts
Authors: Rankine B. C.
Published: November 2006

46 yeasts from 5 genera were examined for ability to decompose L‐malic acid in grape juice. Saccharomyces yeasts decomposed between 3 and 45%, the amount decomposed being somewhat greater in highly acid juice. Schizosaccharomyces malidevorans brought about complete decomposition with stoicheiometric yield of ethanol. Pichia and Candida growing as oxidative films also brought about some decomposition. Mixed cultures of Saccharomyces and Schizosuccharomyces were examined quantitatively. The difference between yeast and bacterial decomposition of L‐malic acid is discussed, as well as the possible selection of yeast cultures for controlled deacidification in wine‐making.
A simple colour test for cold storage deterioration in cod
Authors: Connell J. J.
Published: November 2006

Cod flesh which has been stored in the frozen state under deteriorative conditions gives a blue‐purple colour when dissolved and briefly heated in concentrated acid solution. Fresh cod or cod stored in the frozen state under good conditions give only yellow or brown colours when treated in the same way. Of several commercial species of fish examined, only cod behaves in this way. The phenomenon has been examined in some detail in order to see whether it could be made the basis for a test of frozen cod quality.
The effect of pre‐treatment of pigs with curare on the post‐mortem rate of pH fall and onset of rigor mortis in the musculature
Authors: Bendall J. R.
Published: November 2006

A number of Large White pigs were immobilised before death with curare, and the rate of post‐mortem change in their muscles was compared with that of a group of control pigs.

It is shown that the effect of curare is to give very high and constant initial pH, CP and ATP values in the excised LD muscles, and a slow and constant rate of post‐mortem biochemical and physical change, compared with the very variable rates observed in pigs killed by the normal method of stunning and sticking.

Pig muscle, curarised in this way, shows the low post‐mortem rate of pH fall, characteristic of the muscles of other species, when no nervous stimuli are allowed to reach the muscles before death; for example, muscle from myanesinised rabbits, and surprisingly enough, from myanesinised Danish Landrace pigs, which otherwise often show extremely high and variable rates. Thus, there is little or no difference between breeds or species in the rate or time course of post‐mortem change, when the animals are immobilised in this way before death.

The cause of the extreme variability of rate of fall in pH, observed in pig muscle in ordinary commercial practice, must therefore be sought in the excitement and struggling, produced before and during slaughter by the methods employed, that is to say in the variable intensity of the nervous stimuli reaching the muscles.

It has been experimentally shown that brief electrical stimulation of the excised muscles from the curarised pigs produces not only an immediate increase in the rate of pH fall and of biochemical change, but also has a long‐term accelerating effect, lasting two or more hours, so that the overall rate of change in the stimulated muscles is increased to nearly twice that of the unstimulated muscles. This long‐term effect seems to be unique to pig muscle and does not occur in the muscles of rats, rabbits or frogs, which were the muscles of choice in the classical studies of the chemical changes during contraction.

The bearing of the stimulation effect on the variability of pH fall in commercial practice, and thus on the potential occurrence of pale and watery meat on the carcass, is discussed in detail.
Kaffircorn malting and brewing studies XV.—The fusel oils of kaffir beer
Authors: O'Donovan M. B. , Novellie L.
Published: November 2006

A method for determining the fusel oil content of kaffir beer, based on the A.O.A.C. method for alcoholic beverages, was developed. The average fusel oil content of kaffer beer is high, 227 ppm in comparison with European type beer (average 110 ppm). The increase of fusel oil and ethanol content with time (0‐72 h after seeding) was studied. Abnormally heavy yeast seedings reduced the fusel oil content from 290 to 190 ppm without affecting alcohol production. Combination of heavy seeding and ammonium phosphate reduced the fusel oil to 90 ppm, the level found in many European type beers. The ethanol content was reduced from 3·5 to 2·5% (v/v). Fusel oil produced relative to the amount of ethanol formed revealed that heavy seeding, with and without the addition of ammonium salts, reduced the amount of fusel oil formation by 2/3 and 1/3 respectively.
Synthetic amino‐acids in poultry diets
Authors: Lewis D.
Published: November 2006

An approach is outlined to the formulation of poultry feeds in relation to the economic advantages of meeting amino‐acid requirements either by natural feedingstuffs or by synthetic amino‐acids.
Changes in the non‐volatile organic acids of tomato fruit during ripening
Authors: Davies J. N.
Published: November 2006

A study has been made of the individual non‐volatile organic acids in ethanolic extracts of tomato fruit during ripening. Whole fruit of three varieties and the outer walls and locular contents of one variety each at five stages of ripeness from mature green to full red were analysed.

No trace of many of the K rebs‐cycle acids could be detected. Maximum citric acid concentrations were found at either the green‐yellow or yellow‐orange stage of ripeness according to variety. Malic acid concentrations and the malic/citric acid ratio decreased progressively as the fruit ripened. Glutamic acid increased approximately ten‐fold and aspartic acid more than doubled from the mature green to red stage of ripeness, but changes in pyrrolidonecarboxylic acid (PCA) during ripening were not statistically significant.

In general, similar trends were observed in whole fruit and in the outer walls and locular contents, but malic, citric, glutamic and aspartic acid concentrations were higher in the locular contents than in the outer walls at all stages of ripeness.

Alcohol‐insoluble solids (AIS) decreased markedly between the green and green‐yellow stages and then more slowly with further ripening.
The presence of hexosamine‐containing glycoproteins in wheat flour
Authors: Wrench Pamela M.
Published: November 2006

Material brought into solution from an Australian wheat flour by dilute salt solution and subsequent extraction with dilute acid has a combined hexosamine content of 5 mg per 100 g of flour dry weight. Almost half of the extractable flour hexosamine is present in a dialysed sodium pyrophosphate extract of flour, and half of this is recovered in the heat‐precipitable glycoprotein portion of the pyrophosphate extract. Protease digestion of the glycoprotein gives a major glycopeptide fraction containing 0·24% of hexosamine. This major fraction and several smaller glycopeptides have been further analysed. The results of the analyses are presented and their significance discussed.
Measurement of hypoxanthine concentration in canned herring as an index of the freshness of the raw material, with a comment on flavour relations
Authors: Hughes R. B. , Jones N. R.
Published: November 2006

Hypoxanthine concentration in skeletal muscle increases during the storage of raw herring at 7–12° or in ice.No futher increase occurs during canning and subsequent short‐term storage. Consequently, the concentration of the purine in the canned material affords an index of the quality of the fish at processing. Relative differences in hypoxanthine concentration at points of inedibility are discussed in relation to current flavour theory.
The lead content of pasture herbage
Authors: Mitchell R. L. , Reith J. W. S.
Published: November 2006

On soils in north‐east Scotland derived from quite diverse parent materials, including granitic gneiss, sandstone, slate and mixed acidic and basic igneous rocks, the normal lead content of rotational mixed pasture herbage during the period of active growth is between 0·3 and 1·5 ppm in the dry matter. In autumn, at a date possibly determined by the cessation of active growth and therefore by climatic conditions, the lead content of the above‐ground portion of the plant begins to rise, reaching 10 pprn in late autumn, and may reach 30‐40 ppm in late winter or early spring before growth recommences. At this stage, young shoots with a low lead content appear and the senescent foliage withers away. The increase in lead content of the above‐ground portion when the plant is dormant may indicate movement from the root rather than active uptake of lead from the soil. The possibility of surface contamination by petrolengine exhaust fumes or other industrial materials has been ruled out, and soil contamination of the herbage cannot account for the effect observed. The level of lead in pasture herbage in late winter appears sufficiently high to justify consideration of possible effects on the health of the animal consuming appreciable quantities during this period.
Kaffircorn malting and brewing studies XVI.—the distribution and activity of α‐ and β‐ amylases in germinating kaffircorn
Authors: Dyer T. A. , Novellie L.
Published: November 2006

Unlike barley which possesses β‐amylase activity before germination, sorghum grain is devoid of this enzyme. Both α‐ and β‐amylase are produced during the germination of sorghum and, in any particular malting trial, the ratio of the enzymes to one another remains approximately constant throughout the trial. The actual value at which the ratio remains constant depends on the temperature of the malting and the variety but not on the watering treatment given during malting. The amylase concentration in the embryo is usually higher than in the endosperm but the total amount of amylase in the embryo is much less than in the endosperm. Although the embryo of sorghum is a minor contributor to the total amylase, it contributes more thsn does the embryo of barley to barley malt. The ratio of α‐ to β‐amylase in the embryo differs from that found in the endosperm. In Short Red kaffircorn, a common malting variety, the embryo contained ii significantly lower percentage of αamylase than the endosperm. The opposite was found with the Birdproof and Sugar Drip varieties, the embryo being the richer in αamylase.
Protein denaturation in frozen fish. XI.—The proportion of tissue water converted to ice
Authors: Love R. M.
Published: November 2006

A figure related to the quantity of ice present in frozen cod muscle was obtained by means of a reproducible histological method. In post‐rigor mortis muscle it was found to be unaffected by freezing at a variety of rates, or by freezing muscle which had undergone various degrees of denaturation, but it was reduced when pre‐rigor muscle was used, especially with rapid freezing. The significance of the results in relation to denaturation is discussed.
Tissue and milk residues arising from the ingestion of single doses of diquat and paraquat by cattle
Authors: Stevens M. A. , Walley J. K.
Published: November 2006

The fate of 14C‐diquat and 14C‐paraquat administered orally in single doses to cattle has been studied. In lactating cows, very little (<0.02%) of administered radioactivity appears in the milk, and then largely as metabolic products. Milk obtained in these trials contained levels of paraquat or diquat which in all cases were so low that it could safely be consumed by humans. Only small amounts (< 5%) of the administered radioactivity appears in the urine and in this case also largely as breakdown products. The bulk of the radioactivity appears in the faeces. In a calf slaughtered one day after dosage with 14C‐diquat very little (< 0.01 ppm ion) diquat or its metabolites were found in the muscle tissue. The organs involved in metabolism and excretion, the kidneys and liver, contained relatively small amounts (equivalent to 0·7 ppm and 0·2 ppm ion, respectively) of diquat and its metabolites.
The effect of temperature on ensilage
Authors: McDonald P. , Henderson A. R. , Whittenbury R.
Published: November 2006

An experiment was carried out to study the chemical and bacteriological changes during the ensilage of fresh and partially wilted grass at two different temperature levels. In grass of low dry‐matter content (15.2%) the effect of increasing the temperature to 42° resulted in a clostridial type fermentation, whereas in similar material kept at 20° a lactic acid fermentation occurred. Differences between the two wilted silages were less marked, although the wilted material at low temperature contained more lactic acid than the high‐temperature silage. Results of digestibility trials with sheep did not show any marked variation between treatments, although the digestible crude protein contents were highest in the wet silages. The importance of maintaining low temperatures and of wilting crops prior to ensiling are discussed.
The clarification and deacidification of grape juice by ion‐exchange resins
Authors: Vibhakar S. , Prabhakar J. V. , Bhatnagar H. C.
Published: November 2006

Studies on the clarification (prevention of argol precipitation) and deacidification of grape juice using locally prepared ion‐exchange resins are reported. The process consists of passing the juice through a cation‐exchange column followed by deacidification to the desired level in an anion‐exchange column. The loss of minerals attended by cation‐exchange treatment could be made up by limiting the ion exchange or by blending the ion‐exchange‐treated juice with the fresh juice so that the potassium content of the juice is nearly 100 mg‐%. The juice thus obtained compared favourably with the conventionally clarified juice with respect to clarity, organoleptic quality and chemical composition.
Metabolism of benzoic acid by sheep
Authors: Martin A. K.
Published: November 2006

Experiments have been made with two sheep to determine their ability to synthesise hippuric acid. The titratable acidity of diethyl ether extracts of acidified urine was expressed as g benzoic acid equivalent. One sheep on a dried grass ration and one on a hay and oats ration excreted in the urine 8·06 and 4·07 g benzoic acid equivalent/24 h, respectively, the amounts conjugated with glycine being 2·63 and 2·38 g respectively. When non‐toxic levels of benzoic acid and glycine were infused into the abomasum, complete recovery of infused benzoic acid was obtained in terms of increased titratable acid in ether extracts of the urine. Infusion of 9·6 g of benzoic acid for 24 h as a continuous drip resulted in an increase of 11·89 g of benzoic acid equivalent in the urine, 8·90 g of which were conjugated with glycine. The largest non‐toxic dose given was 53·95 g of benzoic acid which gave rise to an increase in urinary benzoic acid equivalent of 58·47 g, 27·10 g of which were conjugated with glycine. Lethal doses for the two sheep were 1·1 and 1·8 g of benzoic acid/kg body weight. Urine collected during infusion of a toxic dose to one sheep contained a large increment in combined glucuronides. A very large increase in urinary potassium was observed in one sheep given a toxic dose of benzoic acid.
Analysis of crops for residues of ‘Bidrin’ and its metabolites
Authors: Elgar K. E. , Macdonald I. A.
Published: November 2006

In a world‐wide programme of evaluation, ‘Bidrin’ was applied as aqueous solution or as granules to apples, oranges, pears, coffee, cabbages, potatoes, sugar‐cane, sugar‐beet, soil, cotton, olives and grass.

Measurable residues determined by a cholinesterase inhibition–ΔpH method were found on some crops. Residues dissipated fairly rapidly from grass, oranges and soil, but had greater persistence in apples and green coffee beans.

Crops containing high residues measured as ‘Bidrin’ were examined for the presence of the mono‐N‐methylcrotonamide, a known metabolite of ‘Bidrin’, and samples of apples and oranges for the presence of a water‐soluble metabolite. No residue of either compound was found.
Presumptive specific gravity of concentrated citrus juices
Authors: Basker H. B.
Published: November 2006

‘Presumptive’ values of the specific gravity of concentrated citrus juices were computed as a function of their refractive indices, based on the tables of the Ministry of Food, 1943.
Synthesis of the hexaphosphates of myo‐, scyllo‐, neo‐ and D‐inositol
Authors: Cosgrove D. J.
Published: November 2006

Myoinositol hexaphosphate has been prepared by Posternak's method and purified from lower phosphate esters by ion‐exchange chromatography. The product behaved differently from the natural hexaphosphate when used as a substrate for a plant phytase preparation. By modifying Posternak's original method it has been found possible to prepare a synthetic hexaphosphate which is hydrolysed at the same rate as its natural counterpart. The hexaphosphates of scyllo‐, neo‐ and D‐inositol have been prepared by the modified method and have been compared as substrates in phytase hydrolysis experiments.
Amino acid composition of Iraqi dates
Authors: Al‐Rawi N. , Markakis P. , Bauer D. H.
Published: November 2006

Eighteen free and bound amino acids of three commercially packed varieties of Iraqi dates—Hallawi, Khadrawi, and Sayir—were quantitatively determined by means of an automatic amino acid analyser. The following essential amino acids had protein scores lower than 100%: phenylalanine plus tyrosine, isoleucine, lysine, and valine.
The amino acid content of potato plant varieties and their resistance to attack by Phytophthora species
Authors: Child J. J. , Fothergill P. G.
Published: November 2006

Nutritional experiments were carried out to determine the suitability of 22 amino acids as sole sources of nitrogen for the culture of Phytophthora infestans and Phytophthora erythroseptica. The results showed that whilst P. erythroseptica was able to utilise all amino acids supplied reasonably well with the exception of DL lysine, P. infestans was more exacting in its requirements producing reasonable growth on less than half the number supplied. Examination of the free amino acid pool in the tissues of 14 varieties of potato tuber and 8 varieties of leaf showed that approximately 15 readily utilisable amino acids were present as the basic complement in the tuber tissues; the leaf tissues contained a smaller number of amino acids. Additions of water‐soluble tuber extracts to a nitrogen‐limited medium improved the growth of both fungi but the growth response of P. infestans was more varied than that of P. erythroseptica. There was no apparent correlation between the amino acid content of the potato tissues and the amino acid requirements of the parasite in relation to differential varietal resistance.
Disulphide interchange in dough proteins
Authors: Redman D. G. , Ewart J. A. D.
Published: November 2006

Appreciable disulphide interchange has been found between wheat proteins and cystamine when the latter was incorporated into doughs. If the extent of the protein‐protein reaction is of the same order it has been calculated that interchange of this magnitude would be enough to cross‐link the glutenin into a continuous structure. Cysteamine was more reactive than cystamine in the disulphide interchange reaction.
Variations in the composition of oats and barley grown in Wales: (Proximate constituents, available carbohydrate and “1,000 grain weights”)
Authors: Morgan D. E.
Published: November 2006

Proximate analytical data and estimated metabolisable energy values (for poultry) for 171 samples of oats and 179 samples of barley for 3 seasons are presented. The results showed that both grains were extremely variable in crude protein content, the barley rather more so than oats. In contrast, both cereals were relatively constant in calculated metabolisable energy values with oats being more variable than barley. Some of the more important implications of these results in practical livestock feeding are discussed. It is concluded that it would be worthwhile for farmers who home‐mix cereals with concentrates to have samples of grain analysed in order to admix concentrates most effectively and economically. Techniques of sampling however, require to be clearly understood for worthwhile results.
Influence of yeast strain and pH on pyruvic acid content of wines
Authors: Rankine B. C.
Published: November 2006

Pyruvic acid content of wines was investigated on laboratory and pilot‐plant scale and found to be strongly influenced by the strain of yeast used to conduct the fermentation, and pH of the medium, with high pH correlating with high pyruvic acid content. Results obtained with artificial medium confirmed those obtained with grape juice. Yeast strain and pH appear to be the two most important factors influencing pyruvic acid content of wines, and their biochemical and oenological significance is discussed.
New developments in cocoa shade studies in Ghana
Authors: Vernon A. J.
Published: November 2006

Attention is drawn to the lack of confirmation for the results of the Amelonado cocoa shade and manurial experiment, Tafo, K1. The shade of this experiment has recently been determined as reducing the illumination of the cocoa to about 30% ambient light intensity. A survey of local farms has shown their shade to be highly variable on average reducing illumination to about 40% ambient light.

Results of another experiment, and recent yield trends of various unshaded plots at Tafo, are reported. They are in some disagreement with conclusions previously drawn from the results of Tafo K1 and with previous reports of establishing cocoa on clear‐felled land. It appears that the maintenance of a closed canopy is essential to the success of deshaded cocoa. Possible factors are reduction of insect attack, suppression of weed growth, preservation of soil structure, and provision of suitable microclimate.

It is suggested that the use of herbicides may be a critical adjunct to the rehabilitation of unshaded cocoa whose canopy has become broken. Breeding programmes should consider variation in capacity to flourish in bright sunlight.
Organophosphorus compounds. III.—Structure and activity of certain OO‐dialkyl S‐(N‐alkoxycarbonylcarbamoylmethyl) phosphorothiolothionates
Authors: Pianka M.
Published: November 2006

Several dialkyl S‐(N‐alkoxycarbonylcarbamoylmethyl) phosphorothiolothionates and related compounds were synthesised and tested for contact (2 days) and systemic (2 days) activity by root‐uptake against Aphis fabae and Tetranychus telarius. The activity was more affected by increase in the length of the alkyl chain in the phosphate part than by increase in the carbamate part of the compounds. Substitution by a methyl group on the carbon of the S‐methyl reduced activity, whereas substitution by a methyl group on the nitrogen atom broadened the spectrum of activity.
Texture of frozen vegetables: Effect of freezing rate on green beans
Authors: Brown Milford S.
Published: November 2006

The texture of green beans after blanching, freezing and cooking was measured with a shear press. Each processing step reduced shear resistance about the same amount. Visible damage to the vegetable tissues was caused by freezing, but not by blanching or cooking.

Very rapid freezing by immersion in liquid nitrogen prevented damage and reduced the texture degradation. When the freezing rate was slightly slower than that required for perfect preservation, immature cells of the inner parenchyma were the first to be damaged. Further reduction of the freezing rate caused breakage of other cell walls in this tissue, and separation of walls in the outer part of the pod.

When the freezing rate was changed during freezing, the part of the bean that froze rapidly was not damaged, whereas that which froze slowly was damaged. Decreasing the freezing rate during freezing did not damage the portion of the bean already frozen.

Sensory appraisal panels were able to distinguish texture differences in beans frozen at various rates when there were visible differences in the amounts of cell wall damage.
The fatty acid composition and intramolecular structure of triglycerides derived from different sites in the body of the sheep
Authors: Duncan W. R. H. , Garton G. A.
Published: November 2006

Triglycerides were isolated from a number of different tissues obtained from six adult sheep; the tissues including internal fat depots (perinephric and mesenteric), subcutaneous fat depots (rump and chest) and the subcutaneous region of the metatarsal part of the hind limbs and of the pinnae of the ears. The fatty acid composition of these triglycerides was determined by gas‐liquid chromatography and the intramolecular distribution of the acids was studied using pancreatic lipase to remove selectively the fatty acids esterified to the primary alcoholic groups (1‐ and 3‐positions) of the glycerol molecules. Unsaturated fatty acids of the trans configuration were estimated by infra‐red absorption analysis.

In confirmation of earlier, less detailed, studies it was found that the triglycerides of the internal tissues contained a much higher proportion of saturated fatty acids (particularly stearic acid) than did those of the external tissues. In the most exposed tissues (legs, ears) oleic acid accounted for as much as 60‐70% of the total fatty acids present. Trans fatty acid (almost entirely C18 mono‐unsaturated) was, like stearic acid, found in greatest concentration in the internal tissue triglycerides.

Regardless of their location in the body all the triglycerides examined showed a similar pattern of intramolecular distribution of their major component acids; saturated acids (palmitic acid and stearic acid) were for the most part esterified in the 1‐ and 3‐positions, and oleic acid was found predominantly esterified in the 2‐position. Trans unsaturated acid, when present, showed a similar degree of preferential esterification in the 1‐ and 3‐positions to that observed for stearic acid.

It was tentatively concluded that long‐chain fatty acids absorbed from the intestine influence primarily the composition of the triglycerides of internal adipose tissue.
Amino acid analyses of glutenins and gliadins
Authors: Ewart J. A. D.
Published: November 2006

The amino acid compositions of glutenins and gliadins from two strong and two weak wheats have been compared. Glutenin appears to have an amino acid analysis generally similar to that of gliadin but there are individual differences. Glutenin possesses much higher proportions of lysine, glycine and tryptophan and somewhat higher proportions of arginine, tyrosine, threonine, (aspartic acid + asparagine), serine and alanine. Gliadin is richer in proline, (glutamic acid + glutamine), cystine, phenylalanine, amide nitrogen and isoleucine. No definite differences were observed in contents of methionine, valine, leucine or histidine. The possible significance of these results in explaining the properties of glutenin and gliadin is discussed, and the results are compared on a diagram with some analyses in the literature. No significant differences in amino acid composition from variety, or from strong wheats as against weak, were observed among glutenins or gliadins. The calculated factor for converting weight of nitrogen to glutenin or gliadin is 5.6. The mean percentage of (glutamic + aspartic) acids in the amide form is 82 for glutenin and 92 for gliadin.
The effects of three thiols on the extractability of wheat‐flour proteins
Authors: Wren J. J. , Nutt Jill
Published: November 2006

A new technique is described for the progressive extraction of wheat‐flour proteins using columns. Purified sand is the only diluent used, and even packing is made possible by the use of a vacuum. Good rate of flow, filtration of effluents and reproducibility of results are obtained, and air can be excluded if necessary. Solutions of cysteine, dithiothreitol and amyl thioglycollate in water or 40% isopropanol raise the extractability of protein from wheat flour, under some conditions nearly to a quantitative level. Their action is attributed to the depolymerisation of glutenins by disulphide scission. Heating flour to 114° in a microwave oven causes little change in the extractability of proteins, but treatment with 1‐butanol (to remove lipids) markedly lowers the extractability of proteins, even in the presence of thiols.
Seed fats of some New Zealand Juncaceae
Authors: Morice Isobel M.
Published: November 2006

The seed fats of nine species of Juncus L. and five varieties of Luzula DC, both of the family Juncaceae, have been shown to be somewhat similar to one another in fatty acid composition but are nevertheless distinguishable. They differ from those of the family Agavaceae1 in containing the following range of fatty acids: linoleic acid 28‐58%, oleic acid 22‐55%, palmitic acid 6‐19%, stearic acid 1‐4%, linolenic acid 0‐7%, and small amounts of C12, C14, C15, C17,C19, C20, and C24 acids.
A rapid routine test for coliform contamination in food
Authors: Farrell I. , Jayson G. G. , McConlough L. C. , Pirie D. G.
Published: November 2006

A method has been developed for the detection of coliform organisms in foodstuffs which is an alternative to the standard MacConkey test. A relationship has been established between the number of organisms originally present and the time required for their detection. The new method makes use of radioactive tracers and requires less time to confirm the presence of coliform contamination.
Comparison of chemical tests for estimation of the availability of soil zinc
Authors: Martens D. C. , Chesters G.
Published: November 2006

Tests for determining the availability of soil Zn were evaluated by simple and multiple correlation analysis. The soil tests included total Zn, and Zn extractable from soil by 0.2 M MgSO4, 0.1 N HCl or dithizone. In simple correlation analyses, each of the tests correlated significantly with the uptake of soil Zn by maize (Zea mays L.) plants grown in the glasshouse. The predictions were improved significantly with all tests by the inclusion of one or more of the soil variables, pH and clay and organic matter contents, in multiple correlation analyses. The plant uptake of soil Zn could best be predicted from a multiple regression equation which included soil pH and logarithmic functions of 0.1 N HCl‐extractable Zn and soil clay content as the independent variables.
Studies on changes in flour tocopherols following ageing and treatment of the flour with chlorine dioxide
Authors: Frazer A. C. , Lines J. G.
Published: November 2006

The tocopherols in freshly milled flour were measured using two‐dimensional chromatography. Total tocopherols were in the range 1500–1600 μg/100 ml, but only 17–18% of this was α‐tocopherol. Aerobic storage for 190 days caused a reduction of all tocopherols by 62–67%. Treatment of the flour with chlorine dioxide at the usual commercial level caused a comparable reduction, averaging 58%; ϵ‐tocopherol was rather less affected than α‐tocopherol.

Studies in human volunteers indicated that a daily supplement greater than 10 mg of tocopherol was needed to bring about a significant change in the level of α‐tocopherol in the blood. When bread made from untreated and chlorine dioxide‐treated flour was fed to groups of volunteers in a double‐blind crossover trial for 50 days on each type of bread, no significant correlation could be found between blood tocopherol levels and the type of bread consumed. To examine whether a longer period of time on the diet was necessary, the blood tocopherol levels of thirteen English students who had habitually consumed bread made from treated flour were compared with those of thirteen French students, matched for age, who had for several years consumed French bread which is made from untreated flour. The analyses were carried out in Birmingham and in Paris by the same investigator. No significant differences in tocopherol levels were found. It is concluded that the consumption of bread made from flour treated with chlorine dioxide will have no significant effect upon the blood level of α‐tocopherols under the dietary conditions at present prevailing in Britain.
Short‐chain fatty acid analysis—A comparison between two gas‐chromatography methods
Authors: Lough A. K. , Reid R. S. , Murray Moira , Black F. M.
Published: November 2006

The compositions of a number of known mixtures of volatile fatty acids in aqueous solution and of volatile fatty acids in samples of rumen liquor were estimated by two gas‐liquid chromatographic procedures, one of which operated in conjunction with an automatic titrating device and the other with a flame‐ionisation detector. It was found that the method using flame‐ionisation as the system of detection was more accurate and yielded results more rapidly than did that in which automatic titration was employed.
The effect of sulphur‐containing fungicides on the corrosion of plain cans of fruit
Authors: Board P. W. , Holland R. V. , Elbourne R. G. P.
Published: November 2006

The addition of 2–5 ppm of TMTDS (tetramethylthiuramdisulphide) or ziram markedly decreased the shelf life of canned pears, but 1 ppm of these materials had little effect. The addition of trace levels of sulphur or captan to canned pears appeared to increase the shelf life; addition of sodium sulphide appeared to have a negligible effect on shelf life. The shelf life of canned peaches, apricots, pineapple, apples, and citrate solution was also decreased by the addition of 5 ppm TMTDS or ziram. TMTDS and ziram caused pitting of the base steel of the tinplate with little attack on the tin coating. Pitting was not seen in cans containing added sulphur, sulphide, or captan and the rate of corrosion of the tin coating was less than in cans containing no added chemicals. Formation of passive films and reduction of the hydrogen overpotential were considered to be important factors influencing corrosion of cans containing the added agricultural chemicals.
Effect of biochemical constituents on macaroni quality. I.—Differences between hard red spring and durum wheats
Authors: Sheu Ruey‐Yi , Medcalf D. G. , Gilles K. A. , Sibbitt L. D.
Published: November 2006

Durum semolina and farina from hard red spring wheat were fractionated into starch, gluten, watersoluble fraction and sludge. By systematic interchange of the various fractions, a series of reconstituted ‘flours’ was formed. Macaroni was made from these reconstituted materials and the colour and cooking characteristics of these macaroni samples were evaluated. In this way, differences in the effects of the four fractions from the two wheat types on macaroni quality were studied.

Macaroni made from durum wheat had superior colour, higher cooked weight, greater residue and lower firmness score than macaroni made from hard red spring wheat. Interchange of gluten and water‐soluble fractions had the most pronounced effect on macaroni colour and on macaroni cooking characteristics. Interchange of starch and sludge fractions had no effect on colour and only a small effect on cooking quality.
The phospholipids of pork muscle, and their relation to the post‐mortem rate of glycolysis
Authors: Krzywicki K. , Ratcliff P. W.
Published: November 2006

The phospholipids of pork longissimus dorsi muscle were investigated. The proportions of the major phospholipid components appeared to be constant in different regions of the same muscle, although the total lipid‐P varied widely.

Homogenates of the muscle were fractionated by differential centrifuging ‐ ‘myofibrillar’, ‘mitochondrial’, ‘reticular’, and ‘final supernatant’ muscle fractions being obtained. Sarcoplasmic reticulum appeared to be present very largely with the fibrils in the ‘myofibrillar’ fraction, which contained 40–78% of the total lipid‐P. The percentage composition of the phospholipids was similar in the first three sub‐cellular fractions, while the fourth contained less of the ‘kephalin’ component. During fractionation of the muscle, substantial losses of phospholipids occurred; the possible origin and cause of these losses are discussed.

The sum of lipid‐P in the first and third subcellular fractions, containing sarcoplasmic reticulum, showed a highly significant negative correlation with pH1, (muscle pH 45 minutes after slaughter) which represents an approximate index of the rate of post‐mortem glycolysis in the muscle. The significance of this correlation is discussed.
Separation, identification and determination of fluoroacetamide residues in water, biological materials and soils. II.— Identification and determination by gas‐liquid chromatography
Authors: Sawyer R. , Cox B. G. , Dixon E. J. , Thomson J.
Published: November 2006

The methods described, for ‘clean‐up’ and concentration of fluoroacetic acid extracted from water and urine, gave recoveries of about 70 ± 5% of added amounts (0.01–0.5 and 0.05–1 ppm, respectively).
Use of potassium sorbate, diethylpyro‐carbonate and heat for the preservation of prunes at high moisture levels
Authors: Bolin H. R. , Boyle F. P.
Published: November 2006

Normal mould and yeast growth causing spoilage in prunes containing 69% moisture could be prevented by heat processing. At 57% moisture, a dip in 10% potassium sorbate solution was effective for 40–50 days. At 43% moisture, a 5% potassium sorbate dip provided protection and at 34% even a 2% potassium sorbate dip or 550 ppm diethylpyrocarbonate was adequate to inhibit the mould and yeast growth during the 90 day duration of this study.