bluuebunny/crossref_metadata_2025 huggingface dataset:
Volatile aroma components of Australian port wines
Authors: Simpson Robert F.
Published: October 2006

The volatile aroma compositions of a blended port wine, having an equivalent age of 20 years, and a 100‐year‐old port wine were examined by gas chromatography and gas chromatography‐mass spectrometry. The compounds identified were products of yeast fermentation, acetalisation, esterification and oxidation reactions occurring during storage, carbohydrate degradation (of residual grape sugar and wood hemi‐celluloses) and wood extraction. High concentrations of ethyl lactate, diethyl succinate and diethyl malate were found relative to quantities present in young wine. 1‐Ethoxy‐1‐(3‐methylbutoxy)ethane, 1‐ethoxy‐1‐(2‐methylbutoxy)ethane, 1,1‐diethoxypropan‐2‐one, cis‐5‐hydroxy‐2‐methyl‐1,3‐dioxane and cis‐4‐hydroxymethyl‐2‐methyl‐1,3‐dioxolane were identified. The presence of these and other acetals demonstrated that carbonyl compounds were also present. Carbonyl compounds are likely to contribute to the ‘rancio’ flavour of these port wines. Carbohydrate‐derived compounds found included furfural, 2‐acetylfuran, 5‐methylfurfural, ethyl laevulinate, ethyl furoate and 5‐ethoxymethyl furfural. Oak lactone, which is a wood extractive, was also identified and is likely to contribute to the woody aroma distinguishable in these port wines.
A method for the separation of the coloured components of red wines
Authors: Van Dam Tom G. J. , Daniel Roy M.
Published: October 2006

A column‐chromatographic method has been devised which fractionates the coloured components of wines without prior treatment. It employs Sephadex LH‐20 and elution firstly with 10% (v/v) methanol‐in‐water (pH 3.5) and then with a methanol gradient to 65%. The mono and diglucosides of malvidin, and the flavan‐3‐ols, catechin and epicatechin, are among the components subsequently identified by paper chromatography and spectrophotometry. Cabernet Sauvignon, Pinotage, Gamay de Beaujolais, Seibel 5437 and Golden Chasselas wines yielded 17 different major fractions. All wines so far examined had different and characteristic elution profiles. Concentration of a wine prior to chromatography altered the elution profile.
Energy use in bread baking
Authors: Beech Gordon A.
Published: October 2006

A study was made of the energy used in production of standard, white, sliced bread in three UK bakeries. The production chain studied covered all stages from receipt of flour at the bakery to arrival of bread at the retail outlet: primary energy use from all sources averaged 6.99 MJ kg‐1 bread. In the complete production system for standard bread, including wheat growing, flour milling, baking and retailing, primary energy consumption was 14.8 MJ kg‐1 bread and the energy subsidy (primary energy input: food energy output) for the system was 1.49. Primary energy used in home baking was dependent on the degree of loading of the oven and varied from 4.24–16.05 MJ kg‐1 bread baked in a gas oven and from 10.84–54.76 MJ kg‐1 bread baked in an electric oven. In comparison with mashed potato, roast beef and reheated canned corn, standard bread showed the lowest energy subsidy by a factor of at least five. The energy subsidy for standard bread production was only one‐seventh of the figure which applies to the food system as a whole. The findings suggest that bread is the most energy efficient staple food product of an industrialised food production system.
The yield, fatty acid composition and physical properties of milk fat obtained by feeding soya oil to dairy cows
Authors: Banks William , Clapperton John L. , Kelly Morag E. , Wilson Agnes G. , Crawford Robert J. M.
Published: October 2006

The presence in the bovine mammary gland of a desaturase specific for the conversion of stearic to oleic acid allows the manipulation of the physical properties of milk fat by varying the dietary intake of C16 and C18 fatty acids. In particular, feeding the dairy cow an oil with a high C18: C16 ratio should allow the proportion of milk fat that is liquid at 5°C to be increased, with a consequent improvement in the low‐temperature spreadability of butter. In this paper, the effect of feeding concentrate rations containing (a) soya oil as the free oil and as cracked soya beans; (b) various levels of soya oil, the ration being offered twice or 24‐times daily, on the thermal properties of the milk fat and on the yield of milk constituents is examined in detail. Feeding ratios containing free soya oil greatly increased the proportion of milk fat liquid at 5°C, whereas cracked soya oil gave only slight increases. Proportion and yield of milk fat were decreased by feeding soya oil twice daily but were increased by continuous feeding.
Volatile flavour components of malt extract
Authors: Farley Derek R. , Nursten Harry E.
Published: October 2006

The Likens‐Nickerson concurrent steam distillation‐solvent extraction apparatus was used to obtain an essence from malt extract. The essence was submitted to combined gas chromatography‐mass spectrometry (g.c.‐m.s.), to examination by sulphurspecific and nitrogen‐specific detectors, and to sensory evaluation of the components eluted from gas chromatographic capillary columns. Some 33 compounds were identified by direct examination by g.c.‐m.s., another 14 by trapping and re‐injection, which provides an efficient method of concentration, and a further six, which had not been previously identified due to interference from the solvent peak, by the use of charcoal adsorption traps. Results indicate that several compounds need to be combined to simulate malt flavour. The odour contributions of several components are discussed.
Fractionation and amino acid analysis of the salt‐soluble protein fractions of normal and high‐lysine barleys
Authors: Rhodes Anthony P. , Gill Anthony A.
Published: October 2006

High‐lysine barleys derive their high lysine content, in part, from an increase in the salt‐soluble proteins. These proteins were extracted in 0.5m sodium chloride from milled grain of the genotypes Hiproly, Risø 1508, Risø 7, Bomi, Vada and Ark Royal. The extracts were subsequently separated into albumins and globulins by dialysis against distilled water, and were examined by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE) and amino acid analysis. SDS‐PAGE revealed that the polypeptides of both fractions were highly heterogeneous with respect to molecular weight. There were marked differences in the polypeptide composition of the albumin fraction of the high‐lysine genotypes compared to the normals, but relatively smaller differences in the globulins which were generally higher in lysine and lower in glutamic acid than the albumins. The albumin fraction of Hiproly had a very high level of lysine compared to the other genotypes and surprisingly the globulin fraction of Risø 1508 had a low lysine content. The consequences of these findings are discussed in relation to strategies for breeding high‐lysine barleys.
Indices of sugar—acidity as ripeness criteria for winegrapes
Authors: Coombe Bryan G. , Dundon Robert J. , Short Andrew W. S.
Published: October 2006

Requirements for ripeness criteria of grapes for the making of dry table wine are considered, using measurements of sugar and acidity. The performance of indices was assessed by using averages of ‘optimum’ values of musts for top‐quality dry‐white and dry‐red table wines obtained from a survey of prominent South Australian wine‐makers. The defects of the ºBrix: titratable acidity ratio point to the need for an index which combines ºBrix and pH. ºBrix × pH leads to a large spread of pH values at extremes of ºBrix, while Brix:H+ gives an unrealistically narrow pH range. Brix × pH2 appears to be an acceptable compromise.
Fat mobilisation in large white pigs selected for low backfat thickness
Authors: Gregory Neville G. , Wood Jeffrey D. , Enser Michael , Smith William C. , Ellis Michael
Published: October 2006

Plasma free fatty acid (FFA), glucose and insulin responses to feeding and fasting were investigated in a sample of two lines of Large White pigs. One line had been selected for nine generations against backfat thickness and for improved growth rate and feed conversion efficiency. The other line had been randomly bred for six generations. No between‐line differences in the plasma constituents were observed in the fed or absorptive state. This is assumed to be the state in which the pigs were reared since they were without food for a maximum of 16 h daily. An increase in the concentration of plasma FFA, indicating the presence of the starved state, only occurred after 16 h without food. It is suggested therefore that changes in these plasma constituents are not important in the reduced fat deposition in the Selection line pigs. In the starved state, however, the Selection line pigs had higher concentrations of plasma FFA than Control line pigs. The relevance of this finding to the differences in body composition is discussed.
Effect of the introduction of non‐ripening mutant genes on the composition and enzyme content of tomato fruit
Authors: Hobson Graeme E.
Published: October 2006

The genes Never ripe (Nr) and ripening inhibitor (rin) were introduced by backcross programmes into the tomato variety Ailsa Craig to give nearly isogenic lines. The effect of each of these genes on the major constituents of fully‐developed tomato fruit has been studied as part of a programme to select breeding lines bearing fruit having prolonged shelf‐life. The Nr gene produced high acid, low sugar, slow‐ripening tomatoes that were very firm. Because of the adverse effect of this gene on tomato composition, even in heterozygous form, it has little or no commercial potential. The rin gene also led to the production of poor quality fruit. The heterozygote (Rin rin) gave fruit that were similar in compositon to that of the recurrent line, but despite possessing lower polygalacturonase activity were not significantly firmer. The distribution of isoenzymes in the normal and mutant tomato tissues was examined by gel electrophoresis. The majority of the enzymes investigated showed a diminished activity in Nr and rin fruit compared with normal. The very low activities of polygalacturonase, phosphofructokinase and NADP+‐malic enzyme in the fully‐developed mutant lines offers an explanation for the weak climacteric respiration rise and slow ripening of Nr fruit and the non‐climacteric behaviour of rin fruit.
On the alkali degradation type of rice kernels
Authors: Bhattacharya Kshirod R. , Sowbhagya Chakrabhavi M.
Published: October 2006

When immersed in dilute potassium hydroxide solution, milled rice kernels of different varieties undergo different patterns of degradation. Five types of degradation, designated A, B, B1, C and D have been identified. These types correlate well with other quality indices of rice.
Cyclopropene fatty acids in Gnetum gnemon (L.) seeds and leaves
Authors: Berry Shiv K.
Published: October 2006

The seeds and leaves of Gnetum gnemon (L.), a Gymnosperm, were examined for their fatty acid composition by gas‐liquid chromatography, infrared, ultraviolet and nuclear magnetic resonance spectroscopy. They were found to contain cyclopropene fatty acids (CPFA) determined as silver nitrate derivatives of their esters. ‘Keropok’, a product prepared from seeds, was also examined for its CPFA content. The values (area%) for total CPFA were 51.62, 37.87 and 46.91% of the total fatty acids in the oil of seeds, leaves and keropok, respectively. The effect of normal cooking temperatures on the retention of CPFA in these materials was also investigated.
Use of fatty acid methyl esters and edible fats and oils to reduce soft scald of apples
Authors: Wills Ron B. H. , Hopkirk Glen , Scott Kevin J.
Published: October 2006

The incidence of soft scald that developed on Jonathan apples during cool storage was reduced by post‐harvest dipping of the fruit in solutions of a wide range of fatty acid methyl esters and glyceride‐type fats and oils. Compounds which reduced the disorder were: methyl laurate, methyl palmitate, methyl stearate, methyl oleate, methyl linoleate, methyl linolenate, palm oil, sunflower oil, safflower oil, coconut oil, lard and lecithin.
A note on the influence of acetaldehyde on colour of strawberry juice
Authors: Chen Wen‐Pin , Wrolstad Ronald E.
Published: October 2006

Addition of acetaldehyde to strawberry juice caused an increase in colour density and decrease in anthocyanin content on storage. When both acetaldehyde and catechin were added, these changes were intensified. However, addition of catechin alone did not affect colour density. The results indicated that an increase in colour density required the simultaneous presence of anthocyanins, acetaldehyde and catechin. Big differences in colour measured by Hunter colorimeter were also obtained between strawberry juices with and without acetaldehyde.
The effects of formic and propionic acids on the aerobic deterioration of grass silage in laboratory units
Authors: Crawshaw Robin , Thorne David M. , Llewelyn Robert H.
Published: October 2006

A technique is described for the quantification of aerobic deterioration by the measurement of carbon dioxide production in standard laboratory units. It was used to compare the aerobic stability of grass silages made with various levels of formic acid, propionic acid and an additive containing a mixture of the two acids. All three additives were effective in restricting aerobic deterioration when applied at a relatively high rate. Variations in aerobic activity were associated more strongly with bacterial than with mould or yeast growth, though there were differences in the type of microbial activity between the additive treatments.
Effects of textural amendment of coarse soils on seed‐bed water content and seedling emergence
Authors: Stone David A. , Rowse Hugh R.
Published: October 2006

Emergence of cauliflower and radish seeds was increased by incorporation of pulverised fuel ash, and two similar fine‐particle amendments, fluidised combustor ash and ground silica sand, to two coarse‐textured soils. The effect was generally greatest on the coarsest soil and with the highest rates of amendment. From the known hydraulic properties of the treated and untreated soils, seed‐bed water conditions prevailing during the radish field experiment were simulated using a computer program to solve the flow equation for water movement in soil. Simulated soil water deficit and distribution of water loss within the profile agreed well with experimentally determined values. A laboratory experiment on water uptake by radish seeds showed little difference in uptake between seeds in treated and untreated soil at constant potential, despite large differences in water content and hydraulic conductivity. Sufficient water uptake for radicle emergence occurred within 6 h at potentials higher than −0.1 bar. The simulation indicated that potentials in the field did not fall below this level until at least 12 h after irrigation to field capacity. It was concluded that differences in the rate of seed water uptake did not produce the beneficial emergence effects recorded. The data suggest, however, that these are due to differences in water supply during the post‐imbibition pre‐emergence stage of seedling growth.
Condensed proanthocyanidins of fababeans
Authors: Cansfield Peter E. , Marquardt Ronald R. , Campbell Lloyd D.
Published: October 2006

Condensed proanthocyanidins were extracted from fababean hulls with water. The aqueous extract, after deproteinisation by freezing, thawing and acetone precipitation, was purified by chromatography using Sephadex LH20 gel and 95% ethanol developing solvent. Gradient chromatography of the purified condensed proanthocyanidins using 95% ethanol‐(50% v/v)acetone‐water with a Sephadex LH20 column yielded two peaks when the column effluent was monitored at 400 nm. Chromatographic behaviour before and after oxygen treatment indicated certain structural differences between fractions collected under the major peak. There were also considerable differences between the chromatographic properties of material collected from under the major peak and under the minor peak. Solvolysis experiments on the various fractions yielded differences in delphinidin: cyanidin and delphinidin: phlobaphene ratios. There were also differences in ‘tannin’ contents (determined by acidified vanillin methods) and all these differences confirmed that there were structural dissimilarities between the fractions. Tannin determinations made on the hulls of seven different cultivars of fababeans indicated condensed proanthocyanidin levels between 0–6%.
Revised method for quantitating dietary fibre components
Authors: Jeltema Melissa A. , Zabik Mary E.
Published: October 2006

A modification to existing methods of fibre separation and quantification has been proposed. The scheme involves lipid removal with diethyl ether; removal of water‐soluble components and quantification of water‐soluble fibre components; removal of water‐insoluble starch; protein removal; pectin analyses; water‐insoluble hemicellulose quantification; cellulose quantification; and lignin quantification. Simultaneous equations were used to compensate for hexose absorption at the same wavelength as pentoses. Recovery values for individual steps ranged from 90% using a low methoxy pectin to 98% using cornstarch, cellulose, agar or carrageenan. The scheme was used to analyse fibre components in seven wheat brans, maize bran, oat bran, soya bean hulls, potato and apple. Recoveries of fibre and other proximate analyses ranged from 95.9 to 104.7%. Remaining methodological problems are also discussed.
The distribution of acyl lipids in the germ, aleurone, starch and non‐starch endosperm of four wheat varieties
Authors: Hargin Kevin D. , Morrison William R.
Published: October 2006

The quantitative distribution of 23 classes of acyl lipids was determined in the germ, aleurone, starch and endosperm non‐starch fractions of Atou (Soft English), Flinor (Hard English), Waldron (US Hard Red Spring) and Edmore (US Amber Durum) wheats. All four wheats had similar proportions (dry basis) of pericarp (6.8–8.6%), germ (2.5–3.0%), starchy endosperm (78.7–84.5%) and starch (59.3–67.5%), and similar quantities of acyl lipids in the whole kernels (2.8–3.2%), germ (25.7–30.5%), starch (0.8–1.2%) and endosperm non‐starch fractions (0.8–1.1%). Flinor, Waldron and Edmore had 7.3–10% aleurone containing 8.7–10.6% lipids, but Atou appeared to have an abnormally low aleurone weight (4.0%) and a correspondingly high lipid content (19.4%). Pericarp acyl lipids were studied only in Atou, where they comprised 1.3% of the dry weight and 3.8% of the total acyl lipids in the whole kernel. Lipids in the germ and aleurone consisted of triglycerides (60.3–79.3%), other nonpolar lipids (5.6–12.0%) and phospholipids (13.6–17.9%). Starch lipids were almost exclusively lysophospholipids (89.4–94.4%). Greater variation was found in the endosperm non‐starch lipids which consisted of triglycerides (13.7–34.1%), other nonpolar lipids (33.2–48.5%), glycolipids (18.6–38.3%) and phospholipids (21.9–35.3%). Edmore had the highest levels of triglycerides and non‐polar lipids, and the lowest levels of glycolipids (as expected in a tetraploid wheat). Atouresembled Edmore in its low levels of steryl esters and glycolipids, but it also had least phospholipids.
Effects of waterlogging at different stages of development on the growth and yield of winter oilseed rape (Brassica napus L.)
Authors: Cannell Robert Q. , Belford Robert K.
Published: October 2006

Oilseed rape, growing in a sandy loam soil in lysimeters, was subjected to waterlogging to the soil surface at different stages of growth. Brief periods of waterlogging in December and January (10 days) or in May (10 days) resulted in slightly shorter plants but hardly affected yield. Waterlogging in December/January for 6 weeks in cold (1–2°C) weather, slightly restricted leaf development and delayed flowering, but yield was unaffected. At the end of waterlogging for a similar duration between January and March (when the mean temperature was about 6°C), the height and leaf area of the plants was approximately halved, the number of senescent leaves was almost doubled and flowering was accelerated; at harvest in July these plants were 17% shorter and yields of seed, oil and straw were 14, 17 and 23% less, respectively, than for plants in freely‐drained soil. During the prolonged waterloggings short fleshy white roots developed slightly below and on the soil surface.
Natural plant enzyme inhibitors. Isolation and characterisation of a trypsin/chymotrypsin inhibitor from indian red wood (Adenanthera pavonia) seeds
Authors: Prabhu K. Sudhakar , Pattabiraman Thillaisthanam N.
Published: October 2006

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The ratios of the logarithms of reciprocals of flavour (combined odour/taste) or odour, thresholds in aqueous and oil media can be significantly linearly related to the octanol/water partition coefficients (as log P) of the compounds considered. The use of this lipophilicity parameter to relate thresholds determined in different media may allow the estimation of thresholds in oil media, or oil‐based food products, from the thresholds in water.
Countercurrent extraction‐isoelectric precipitation of sunflower seed protein isolates
Authors: Taha Fakhriya S. , Abbasy Mehassen , El‐Nockrashy Ahmed S. , Shoeb Zein E.
Published: October 2006

A countercurrent extraction‐isoelectric precipitation procedure for the preparation of protein isolates from defatted sunflower seed meal is described. Using 0.04M NaOH and a solvent:meal ratio of 20:1, as much as 95% of meal nitrogen was extracted. Precipitation at pH 4.0 resulted in an isolate containing 88.4% of the meal protein. Using 0.1% sodium sulphite with the alkaline solution in the countercurrent extraction resulted in a white, bland and highly pure protein isolate. Isolated sunflower seed protein is limiting in the amino acid lysine, while other essential amino acids are present in amounts which meet the dietary requirements of chicks and human adults.
Effects of adding chelated and non‐chelated copper and cobalt to a deficient soil on the content of these nutrients in clover and ryegrass
Authors: McLaren Ronald G. , Williams John G.
Published: October 2006

In a pot trial carried out with a mineral‐deficient soil, applications of copper and cobalt significantly increased the content of these nutrients and manganese in ryegrass and clover. When used at the same rate of application of copper or cobalt, EDTA chelates were found to be no more effective than simple sulphates in increasing the copper and cobalt content. Low rates of application of copper‐EDTA produced insignificant increases in the copper content of herbage, and increases in cobalt content brought about by low application rates of cobalt‐EDTA were short lived. Incorporation of copper sulphate into the soil produced far larger increases in herbage copper concentration than copper sulphate applied to the soil surface.
Evaluation of sulphate status of soils by plant and soil tests
Authors: Scott Norman M.
Published: October 2006

The relationships of the amounts of sulphate extracted by different extractants with the yield, response to added sulphate, and the sulphur uptake of oats in pot cultures have been studied for ten acid soils. The L‐value, representing the quantity of isotopically exchangeable sulphur sampled by the plants, was estimated using radioactive sulphur. The best relationships with the crop variables were given by sulphate extracted with calcium chloride, potassium dihydrogen phosphate and sodium bicarbonate. Critical values, below which a response to added sulphate is likely to be obtained under the pot conditions, are given for the phosphate and bicarbonate extractants.
An investigation of analytical procedures for predicting soil nitrogen supply to grass in the field
Authors: Whitehead David C. , Barnes Ralph J. , Morrison John
Published: October 2006

Procedures based on five methods of soil analysis for predicting potentially mineralisable N, and hence soil N supply, have been evaluated and compared with prediction based on total soil N. The effect of adjusting the analytical results for differences in soil temperature and water status between sites has also been examined. The evaluation was performed by calculating the extent to which the results accounted for variation in the amounts of N in the herbage of perennial ryegrass plots receiving no fertiliser N. The plots were situated at 18 sites throughout the UK: at some sites results were available for more than 1 year, giving a total of 29 site/years. The best prediction, accounting for 65 % of the variation in herbage N yield, was obtained when the amounts of ‚glucose’︁ extracted from the soils by 0.05M Ba(OH)2 were combined with the amounts of NO3‐N extracted by 2M KC1, and the combined values adjusted for soil temperature and water status. A procedure based on the measurement of the NH4‐N released by autoclaving the soils with 0.01M CaCL2 accounted for 51 % of the variation However, procedures based on (a) NH4‐N extracted by acid KMnO4, (b) non‐NO3‐N extracted by 0.01M NaHCO3, and on (c) measurement of the absorbance at 260 nm of NaHCO3 extracts, were no more effective than was analysis for total soil N (less than 36% of the variation accounted for when values were adjusted for soil temperature and water status).