bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of variety, site and storage on physical, sensory and compositional aspects of mashed potato
Authors: Faulks Richard M. , Griffiths Nerys M.
Published: October 2006

Over two seasons, eight potato varieties were grown locally and the three principal UK maincrop varieties at different sites. After periods of storage domestically prepared mashed potato was made from this material and assessed for back extrusion, adhesion, particle and cell size and distribution, ‘free’ starch, dry matter and cell wall polysaccharides in conjunction with sensory textural assessments for mealiness, moisture and structure. The results indicate that there are strong correlations between the physical measurements of work done during back extrusion (EWD) and the deformation to peak adhesion force (ADP) with both dry matter (DM) and the mean sensory scores for mealiness, moisture and structure. The sensory characteristics were also highly interdependent. The r value of these relationships declines after prolonged storage. No significant correlations were found between particle size or cell size and distribution and any of the physical, sensory or compositional data at any storage time. With the three principal UK maincrop varieties, site influenced DM and hence physical and sensory texture more strongly than variety.
The aroma of blueberries
Authors: Hirvi Timo , Honkanen Erkki
Published: October 2006

The volatile components of bilberry, bog blueberry and cultivated high‐bush blueberry (cv. Rancocas) were analysed by gas chromatography and mass spectrometry. Several new compounds not reported previously as blueberry volatiles were detected. These included methyl and ethyl 2‐hydroxy‐3‐methylbutanoate, methyl and ethyl 3‐hydroxy‐3‐methylbutanoate, 2‐phenylethyl formate, methyl salicylate, farnesol, farnesyl acetate, vanillin, myristicine, 4‐vinylphenol, 2‐methoxy‐5‐vinylphenol, citronellol, hydroxycitronellol and some γ‐ and δ‐lactones. The character impact compounds of bilberry were found to be the above‐mentioned hydroxy esters together with 2‐phenylethanol and its esters and the γ‐ and δ‐lactones, whereas myristicine, citronellol, hydroxycitronellol, farnesol and farnesyl acetate were typical of the aroma of high‐bush blueberry.
Some aspects of the use of high‐performance liquid chromatography for the determination of vitamin A in animal feeding stuffs
Authors: Lawn Richard E. , Harris John R. , Johnson Steven F.
Published: October 2006

The application of high‐performance liquid chromatography to the determination of vitamin A in animal feeding stuffs has been investigated. Particular emphasis has been given to some of those aspects that would be of importance to official control methods. Vitamin A exists as six geometric isomers, some or all of which may be present in feed extracts. The effect of this on both ultraviolet and fluorescence quantitation is described, using all‐trans retinol and 13‐cis retinol as examples of the different isomers. The isomers were eluted coincidentally from a reversed‐phase column; information on the isomeric composition of the feed extracts was obtained by means of the maleic anhydride reaction. These results were confirmed by a normal phase chromatographic procedure which resolved all‐trans and 13‐cis retinol.
Silage fermentation of fish or fish waste products with lactic acid bacteria
Authors: Lindgren Sven , Pleje Mats
Published: October 2006

Silage fermentation of minced fish and fish offal after inoculation with cereals prefermented with Pediococcus acidilactici and Lactobacillus plantarum initiates a rapid fall in pH to below 4.5 within 30 h, and the content of competing gram‐negative fermenters and fish pathogens, such as Vibrio anguillarum and Aeromonas salmonicida, is eliminated. The addition of 0.1% sorbic acid inhibits the growth of yeasts during the initial fermentation period and during storage but does not affect the lactic acid fermentation. Degradation of nitrogen components proceeds during storage and is manifested as an increase in volatile basic nitrogen compounds, amino acids and peptides. These substances increase the pH and/or force the bacteria to produce more acid. The rate of production of these basic substances is mainly temperature‐dependent and cannot be attributed to microbial activity. The proteolytic activity is mainly caused by tissue proteases (e.g., cathepsins) and, to a lower degree, by gut proteases. It is doubtful whether fish fermentation can be utilised on an industrial scale without improving the technique. Such improvements consist of the selection and use of psychotrophic lactic acid fermenters and commercially acceptable inhibitors of proteolytic activity and yeast growth.
Carbohydrate and phenolic constituents in a comprehensive range of rapeseed and canola fractions: Nutritional significance for animals
Authors: Blair Robert , Reichert Robert D.
Published: October 2006

Cotyledons from 11 varieties of rapeseed and canola seed were extracted with hexane and analysed for tannins, α‐amylase inhibition value, starch and available carbohydrate by conventional methods. The sinapine content (total sinapic acid esters plus free sinapic acid) was determined by a spectrophotometric method. Samples of soya bean cotyledons, high‐tannin sorghum grain and commercial rapeseed and canola meals were also analysed for comparison. Sinapine in rapeseed and canola cotyledons was measured at mean levels of 2.67 and 2.85% respectively. Tannins were detected in these cotyledons but only at low levels. The α‐amylase inhibition values were also low or negative. Starch was detected in negligible amounts, and available carbohydrate at 13–14%. The predicted metabolisable energy (ME) value of commercial rapeseed or canola meal for poultry was found to be numerically close to the determined value when the available carbohydrate value was reduced to 35% of the observed value.
Purification, characterisation and kinetics of a trypsin inhibitor from black gram (Vigna mungo)
Authors: Kamalakannan Vedhachalam , Sathyamoorthy Venugopal , Motlag Dinkar B.
Published: October 2006

A black gram (Vigna mungo) trypsin inhibitor (BGTI) was purified to homogeneity by ammonium sulphate precipitation, DEAE‐cellulose chromatography and affinity chromatography. The homogeneity of the inhibitor was identified by polyacrylamide gel electrophoresis (PAGE), SDS–PAGE, immunodiffusion and immunoelectrophoresis. The isoelectric point of BGTI was 8.32. The molecular weight of the BGTI was found to be about 12500 by both gel filtration and SDS–PAGE. One mole of the BGTI was found to contain 75 amino acid residues, and it was identified as a glycoprotein, comprising about 18.2% carbohydrate. The BGTI was an uncompetitive inhibitor, stable in the pH range 2–10 and in the temperature range 30–80°C for 30 min.
Flavonol glycoside distribution in cultivars and hybrids of Leucaena leucocephala
Authors: Lowry J. Brian , Cook Neil , Wilson Raymond D.
Published: October 2006

Flavonol glycosides found in the leaves of Leucaena leucocephala comprised the 3‐arabinosides, 3‐rhamnosides and 3‐glucuronides of quercetin and myricetin, and quercetin‐3‐rhamnosylglucoside, at a total concentration of 3–4%. In cultivars of high productivity (Peru, El Salvador (K28) and Cunningham) all seven compounds occurred with a largely constant pattern of relative concentrations. However in the cosmopolitan form naturalised throughout the tropics the 3‐arabinosides were invariably absent. The same feature which was conspicuous on the high performance liquid chromatography trace, occurred with a low frequency (ca 10%) in Peru and Cunningham. The pattern provides a quick method for identifying the provenance of commercial leucaena leaf meal, and also for detecting blending or adulteration with other leaf meals. The flavonol glycoside distribution of those species associated with ‘leucaena’ leaf meal (Acacia villosa, Calliandra calothyrsus, Manihot utilissima and Sesbania grandiflora) is very different, and all have fewer compounds. All compounds occur in the apical tissue of young leucaena seedlings, enabling identification of cultivar from seed in 10 days. Comparison of leaf flavonol patterns for L. leucocephala, L. pulverulenta their known F1 hybrid, and an entity known locally in Java as ‘L. glabrata’ strongly suggest a hybrid origin for the latter.
An isotopic method for determining chemically reactive lysine based on succinylation
Authors: Anderson Trevor R. , Quicke George V.
Published: October 2006

A method is described for the routine succinylation of proteins using [14C]succinic anhydride as a means of measuring free ϵ‐amino groups. Maximal succinylation was achieved using 6M guanidine hydrochloride as protein solvent and an 80‐fold molar excess of succinic anhydride relative to total lysine residues. Treatment with hydroxylamine (pH 13, 25°C, 5 min) removed unwanted O‐succinyl esters. Succinylated protein was precipitated with trichloroacetic acid, residual label washed out with ethanol and the extent of labelling measured in a scintillation counter. The method gave close to theoretical values (n.s., P >0.05) for lysyl residues in egg white lysozyme, bovine haemoglobin, ovalbumin and bovine serum albumin but gave a low value with β‐lactoglobulin and an overestimate with insulin attributable to the relatively high contribution of α‐ relative to ϵ‐amino groups in this low molecular weight protein. The method gave good results for 12 soya protein samples and was shown to be very sensitive to ‘isopeptide‐type’ heat damage in these samples. The results correlated well (r = 0.91) with those obtained by the well established dye‐bound lysine difference procedure whereas, as could be expected, both these methods correlated poorly with total lysine determinations (r=0.69 for succinic anhydride and r=0.77 for the dye‐binding method). The proposed method shows promise as a rapid procedure for the estimation of available lysine, but further studies are necessary to test its ability to measure nutritionally available lysine in all categories of heat damage.
Air classification of pea flour–analytical studies
Authors: Wright David J. , Bumstead M. Rachel , Coxon David T. , Ellis Hugh S. , DuPont M. Susan , Chan Henry W.‐S.
Published: October 2006

The pea‐milling and subsequent air classification of whole peas was investigated on laboratory scale equipment. Two approximately linear but divergent calibration graphs were constructed for the air classifier based on two different definitions of particle size cut‐point. At high classifying speed (11 000 rev min−1) a fine fraction or protein concentrate was produced containing 55.1% protein (cf. 22% in original flour) although this represented only 29% of the total protein. The yield of protein in the fine fraction could be increased by using a three‐stage milling and classifying procedure, although the actual protein content of the concentrate remained more or less the same. This procedure also had the effect of reducing protein contamination of the starch (coarse) fraction. Other effects of air classifying observed included the concentration of the lipid component into the fine fraction and the rough fractionation of the fibre constituent between the coarse (testa) and fine (cell wall material) fractions. Various aspects and problems associated with the use of air classification for the preparation of pea protein concentrates are discussed.
The use of free‐choice profiling for the evaluation of commercial ports
Authors: Williams Anthony A. , Langron Steven P.
Published: October 2006

The paper describes a new approach to profile analysis in which each assessor produces individual profiles of the products, using his or her own terms for describing them without the need to explain the meaning of such terms. The spatial configurations derived from individual profiles are rationalised by generalised Procrustes statistics. The result is a consensus configuration revealing the interrelationships between the samples for the panel as a whole. An experiment conducted on commercial ports using ten assessors, both expert and non‐expert, illustrates the technique.
Carboxy distribution of low‐methoxy pectin deesterified in situ
Authors: Tuerena Colin E. , Taylor Andrew J. , Mitchell John R.
Published: October 2006

The distribution of free carboxy groups in a series of orange pectins deesterified in situ by enzymic and alkaline action has been measured. A sharp change in the average free carboxy block size of enzymically deesterified pectin at a degree of esterification of about 25% was found. At degrees of esterification below this value, a number of blocks of free carboxy groups with degrees of polymerisation greater than 30 were found, whereas at higher degrees of esterification blocks as large as this were virtually absent. This may be explained in terms of the action of two pectinesterase isoenzymes which have affinities for high and low methoxy pectins, respectively. This work provides an explanation for the sharp decrease in gelling performance found for treated orange peel in heat processed systems as the degree of esterification of pectin increases above 25%.
A system for the measurement in the field of losses of ammonia through volatilisation
Authors: Lockyer David R.
Published: October 2006

A detailed description is given of the construction and operation of a system of small wind‐tunnels used in the measurement of ammonia volatilisation from grass swards. In the design of the system, emphasis was placed on the requirements that (i) natural sward conditions should be influenced as little as possible, and (ii) airspeed through the tunnels should be controllable in the range normally encountered in the field. An analyser is described which incorporates an ammonia‐sensing probe; it was used to monitor automatically and continuously the concentration of ammonia in air entering and leaving the tunnels. The tunnels were found to have only small effects on sward conditions. Differences between simultaneous measurements of temperature made inside and outside the tunnels were rarely more than 1°C for air temperature and 2°C for soil temperature at 3 cm depth. The potential of the system was examined in a study comparing the loss of ammonia through volatilisation from swards treated with natural urine or an artificial urine. There were marked differences in the rates of volatilisation from the two urines although the total loss of nitrogen was similar from both, amounting to about 3% of the nitrogen applied.
A quantitative analysis of amino acid accumulation in developing grain of normal and Opaque‐2 maizes
Authors: Landry Jacques , Moureaux Thérèse
Published: October 2006

From previous observations concerned with the qualitative and quantitative evolution of protein groups in developing maize (Zea mays L.) grain, it may be deduced that the amount per grain of any amino acid incorporated into the proteins is linearly related to the amount of true protein in the grain. In this study, such a linear relationship is characterised quantitatively from experimental data by regressing the individual amino acid against the total protein accumulated in the developing grain of both normal (+) and opaque‐2 (o2) maize. The linear least squares regression on total nitrogen content in the grain is also used for specifying the quantitative variations of any free and protein‐incorporated amino acid in the grain. The slope Bj of the regression line represents the relative rate of accumulation of amino acid (j) in grain protein (or nitrogen) and its limiting content in protein (or nitrogen) of a grain which accumulates a large amount of it. Bj, which is compared to the amount of amino acid (j) present in the protein of immature grains, or of mature endosperm, or germ, is close to the amount of amino acid (j) present in the protein of mature endosperm. The same holds for the Bj value determined from opaque‐2 maize and which differs from the amount of Bj determined using the normal variety for many amino acids. Using experimental data reported in the literature, a linear relationship has also been found in describing quantitative variations of amino acid in the developing grain of normal and Hiproly barley.
Interactions between soil and fertiliser in the supply of nitrogen to ryegrass grown on 21 soils
Authors: Whitehead David C.
Published: October 2006

Perennial ryegrass (Lolium perenne L.) was grown in pots on 21 UK soils, both with and without fertiliser N. The fertiliser N was applied in six equal applications of 15N‐labelled ammonium nitrate, each at the rate of 120 mg N per pot. The first application was mixed thoroughly with the soil, while subsequent applications were made in solution to the soil surface, after each of the first five of the six harvests of herbage. In the absence of fertiliser N, the proportion of the total soil N taken up by the plants, including stubble and roots at the sixth harvest, varied between 1.5 and 4.0%. In the presence of fertiliser N, the proportion varied between 2.1 and 4.7%. The apparent recovery of the fertiliser N was calculated from the difference between the amounts of N in the plants that received fertiliser N and in those that did not, expressed as a percentage of the amount applied. The actual recovery of the applied fertiliser N was determined by analysis of the plant material for 15N. With all soils at the first harvest, the apparent recovery was greater than the actual recovery. When calculated over all six harvests, apparent recovery of the total amount of fertiliser N was generally close to the actual recovery. This difference from the first harvest probably reflected (i) a reduction in the extent of turnover between fertiliser N and soil N when the fertiliser N was applied to the surface and (ii) a virtually complete uptake of available soil N by the end of the experiment, in both the absence and presence of fertiliser N. Differences between the 21 soils in actual recovery were not closely related, either positively or negatively, to a range of measured soil properties. A mean of 17.2% of the labelled fertiliser N was retained in the soil (excluding visible roots) at the end of the experiment. The lowest retention (6.2%) occurred with the soil which had the lowest contents of organic matter and silt plus clay but, with the other soils, the extent of retention varied only between 14.7 and 22.0% of that applied, and was not closely related to contents of total organic matter or macro‐organic matter, or to the C:N ratio of the whole soil or the macro‐organic matter.
Determination of thiobarbituric acid reactive substances (TBARS) in fish tissue by an improved distillation–spectrophotometric method
Authors: Ke P. J. , Cervantes E. , Robles‐Martinez C.
Published: October 2006

An improved method for determining the thiobarbituric acid‐reactive substances (TBARS) in fish tissue has been described. The biological sample was digested in acidic media and then separated by using specific reflux distillation. The compounds in distillate were estimated by spectrophotometric measurement at 538 nm after the reaction with 2‐thiobarbutanic acid. The operational errors, interferences and the recovery of malonaldehyde standard and TBARS from tissue sample using the described procedure have been studied. The recommended technique is simple and reproducible with a detection limit of 0.2 nmol TBARS per 10 g of tissue sample and an overall deviation of less than 7%. The recommended method has been applied satisfactorily for evaluation of rancidity studies in various fish samples.
Changes in the composition of volatiles by post‐harvest application of alcohols to red delicious apples
Authors: Berger Ralf G. , Drawert Friedrich
Published: October 2006

The effect of exogenous short‐chain n‐alcohols on the concentrations of main aroma components in mature intact Red Delicious apples and aged apple tissue discs has been studied. Storage of intact apples in an atmosphere containing ethanol vapours for 24 h resulted in a more than threefold increase in the sum of ethyl ester concentrations. The simplified model of tissue discs was applied to examine the influence of various ethanol concentrations on rate and time course of ester formation. On supplying a range of n‐alkan‐1‐ols and 2‐keto valeric acid in equimolar amounts to the discs, maximum conversion into esters was found with butanol and pentanol. The possibility of an in vivo aroma enrichment before processing of fruits is discussed.
Analysis of oil content of groundnuts by nuclear magnetic resonance spectrometry
Authors: Jambunathan Ramamurthi , Raju S. Madhusudana , Barde Shubhada P.
Published: October 2006

One hundred groundnut germplasm accessions were analysed for their oil content by the standard Soxhlet extraction procedure using petroleum ether: the results were compared using functional analysis with those obtained with a commercial nuclear magnetic resonance (n.m.r.) spectrometer. On another 78 experimental samples, oil content was first obtained using the n.m.r. method and the Soxhlet values were predicted using the above functional relationship. On the 78 samples the predicted values were highly correlated (r=0.972) with those obtained by Soxhlet extraction. The n.m.r. method is rapid, easy, acurate and non‐destructive.
Congener profiles in the detection of illicit spirits
Authors: Simpkins Wayne A.
Published: October 2006

A range of spirituous beverages available in Australia has been analysed for the major volatile congeners using gas chromatography. A data bank has been generated and its use and limitations in the detection of illicit spirits is discussed. The spirits include Australian and imported brandies, tequilas, grappas, fruit brandies, wine fortifying spirits, rums, whiskies including bourbon, malt and blended scotch, gins, vodkas and sundry other beverages. Methanol. acetaldehyde, 1‐propanol, 2‐methyl‐1‐propanol, 2‐butanol, 1‐butanol, 2‐methyl‐1‐butanol. 3‐methyl‐1‐butanol, ethyl lactate and ethyl acetate were determined.
Colour measurement of fish minces using hunter L, a, b values
Authors: Young Kenneth W. , Whittle Kevin J.
Published: October 2006

Hunter L, a and b values are used to order fish mince colour according to species or processing parameters. Mince colour difference (ΔE) or statistical examination of L, a and b values are used to establish a 3‐dimensional plot to illustrate colour differences between samples.
Volatile off‐flavour compounds in desiccated coconut
Authors: Kellard Brian , Busfield David M. , Kinderlerer Judith L.
Published: October 2006

Aliphatic methyl ketones and secondary alcohols have been isolated from desiccated coconut and shown to be responsible for the rancid off‐flavour. Two series of compounds have been isolated. The series with an odd number of carbon atoms (C5,7,9,11) comprising pentan‐2‐one, pentan‐2‐ol, heptan‐2‐one, heptan‐2‐ol, nonan‐2‐one, nonan‐2‐ol and undecan‐2‐one is derived from even chain fatty acids one carbon atom longer, present in the coconut oil by a modified β‐oxidation due to growth of moulds. Heptan‐2‐one and nonan‐2‐one were present in the greatest concentration in the rancid coconut. These compounds gave an odour reminiscent of rancid almonds and turpentine respectively while heptan‐2‐ol and nonan‐2‐ol gave an odour similar to rancid coconut as well as a musty, stale odour. This type of off‐flavour has been called ketonic rancidity and is an oxidative variation of the hydrolytic type of rancidity. The presence and origin of the even numbered series (C6,8), hexan‐2‐one, hexan‐2‐ol and octan‐2‐one is discussed. The increase in C5,6,7,8,9,11 oxidation products in the rancid samples occurred at the expense of C8,10,12 short chain fatty acids.
Partial purification and some properties of the lipase present in oil palm (Elaeis guineensis) mesocarp
Authors: Abigor Doye R. , Opute Fred I. , Opoku Andy R. , Osagie Anthony U.
Published: October 2006

The fatty layer obtained by centrifuging a homogenate of oil palm fruit mesocarp contains an active lipase. The lipase which was partially purified using a combination of ammonium sulphate fractionation, ion exchange and gel filtration chromatography, indicated an optimum activity at pH 4.5 and a temperature of 30°C. The enzyme exhibited good activity towards its natural substrate, palm oil as well as glycerol trioleate and glycerol tripalmitate. It also showed a linear reaction rate for the first 20 min of incubation. Sodium cyanide, resorcinol, cholesterol, lecithin and glycylglycine strongly inhibited its activity while phenol, L‐cysteine and EDTA enhanced its activity. It is suggested that the lipase is associated with the membrane of the oil droplets.
Dietary fibre of coconuts from a pacific atoll: Soluble and insoluble components in relation to maturity
Authors: Monro John A. , Harding Winsome R. , Russell Catherine E.
Published: October 2006

Polysaccharide fractions were measured in coconuts at three stages of maturity, which corresponded to dietary usage in the Tokelau Islands of the South Pacific. Kernel was sequentially extracted with cold water (CW), hot water (HW) hot 0.5% ammonium oxalate (HOX), 1M H2 SO4 and 72% H2 SO4, and the monosaccharide compositions of the fractions determined. Total readily soluble fractions (CW+HW+HOX) were predominantly galactomannan, and decreased from 77% of the polysaccharide in the immature kernel to 8.8% of that in the mature kernel. Insoluble mannan increased during maturation to be the major polysaccharide component in mature kernel. This indicates that marked differences exist between the three stages of maturity examined, in the properties of their dietary fibre. The results suggest that in studies of diets in which coconut is a staple part, there is a need for careful definition of the coconut component with respect to maturity. Furthermore, they show the importance of using dietary fibre methods which are appropriate to the solubility characteristics of the indigestible polysaccharide.
Folacin content of alfalfa and mung bean sprouts: The effect of extraction procedures and maturity
Authors: Magaram Marilyn F. , Stotts Cynthia L. , Chen Tung‐Shan , Smith Christine H. , Kirsch Arlene J.
Published: October 2006

The folacin content of alfalfa (Medicago sativa) and mung bean (Vigna radiata) sprouts was determined by Lactobacillus casei. Several variations of extraction procedures were tested. The optimum conditions for extraction were autoclaving mung bean and alfalfa sprouts in phosphate buffer containing 0.3% and 0.4% ascorbate, respectively, before homogenisation in a blender. The optimum blending time for folacin extraction was 120s for mung bean and 15s for alfalfa sprouts. Folacin content on dry weight basis increased several times in both types of sprouts during germination. Mature alfalfa and mung bean sprouts were found to contain 186 and 178 μg folacin per 100 g fresh weight, respectively.
A modified procedure for the purification of vicine and convicine from fababeans (Vicia faba L.)
Authors: Arbid Mahmoud S. S. , Marquardt Ronald R.
Published: October 2006

A procedure was developed for the simultaneous isolation of pure vicine [2,6‐diamino‐4,5‐dihydroxypyrimidine 5‐(β‐D glucopyranoside)] and convicine [2,4,5‐trihydroxy‐6‐aminopyrimidine 5‐(β‐D glucopyranoside)] from dehulled fababeans. The procedure involved the extraction of the glycosides with an ethanol‐water (70:30, by vol.) solution, concentration of the extract to a minimal volume and adjustment of the pH of the aqueous extract to 7.2. Mixed vicine and convicine crystals, which were formed over a period of from 1 to 4 days, were harvested by centrifuging and washed with water and ethanol. Vicine was readily obtained from the mixed crystals by extraction at a low pH and recrystallised by adjustment of the pH to neutrality. Convicine, which is relatively insoluble in an acidic medium, was solubilised in an alkaline solution and recrystallised at a neutral pH.
Formaldehyde as an interference of the 2‐thiobarbituric acid test
Authors: Almandós Maria E. , Giannini Daniel H. , Ciarlo Alicia S. , Boeri Ricardo L.
Published: October 2006

The 2‐thiobarbituric acid (TBA) test is widely used for measuring rancidity in foods. It is based on the colorimetric determination of a pink chromogen which is formed by reaction between TBA and TBA reactive substances (TBARS). Besides malonaldehyde (MA) many other substances have been reported to react with TBA. The formation of formaldehyde (FA) from the trimethylamine oxide (TMAO) decomposition in sea fish has been extensively studied. Considering that FA reacts with the TBA forming a white precipitate or cloudiness the interference of FA with TBA test is studied concluding that FA contents over 25 μg ml−1 extract interfere with the colorimetric determination during the storage of frozen blocks of Patagonian hake (Merluccius hubbsi) filleted and minced.
Analysis of cocoa pulp and the formulation of a standardised artificial cocoa pulp medium
Authors: Pettipher Graham L.
Published: October 2006

Results of analyses of cocoa pulp from the Ivory Coast, Nigeria and Malaysia are reported. These include pH, viscosity and aw measurements and concentration of soluble sugars, vitamins and anions. Pulp from Malaysian cocoa pods had a higher water content, lower citrate, hemicellulose, lignin and pectin concentration and a higher pH than Ivorian or Nigerian cocoa pods. The composition of a defined cocoa pulp medium which has the same overall composition, pH, aw and viscosity as cocoa pulp is described. The defined cocoa pulp medium supported the growth of yeasts, lactic acid bacteria and acetic acid bacteria.
Protein concentration of grain in relation to some weather and soil factors during 17 years of english winter‐wheat experiments
Authors: Benzian Blanche , Lane Peter W.
Published: October 2006

Results from a long term study of wheat experiments on Rothamsted farm were examined by multiple regression analysis to estimate the size of the contributions made by four weather factors to the year‐to‐year variance of grain protein. Whether considered singly or in either of two chosen models, air temperature during the early part of the grain‐filling period had a positive effect, incident radiation during the early or middle part a smaller negative effect. Both models accounted for 25% of the total variance or 60% of the year‐to‐year variance. After fitting either model winter leaching and maximum potential soil‐moisture deficit were not significant. Closely matching results were obtained by including 15 nearby farms. Some soil factors were investigated in a similar manner. A soil N index accounted for 30% of the total variance, with grain N% of 1.95 corresponding to Index 0 and 2.23 to the average of 1 and 2. In models combining the best weather and best soil variables (N Index and wetness class), the variance accounted for was 46%, with all effects significant. There were significant interactions of radiation, winter leaching and soil wetness class with the response to fertiliser nitrogen. As the yield data are less well based than those for grain N% their relationships were examined only in parallel to the main study.
Mass spectrometric determination of waxy corn (Maize) starch in glutinous (waxy) rice cake by use of 13C/12C ratio
Authors: Yasui Takeshi
Published: October 2006

Glutinous (waxy) rice cake is a popular New Year food in Japan. Economic incentives exist for rice cake producers to adulterate the products and mislabel them. Stable carbon isotope ratios (13C/12C) in rice cake products were determined by mass spectrometry to detect such adulteration. Since the 13C/12C ratios in rice (δ13C value of ca ‐ 25 ppt, parts per thousand are different from those of corn (maize) starch (ca −9 ppt), the presence of added waxy corn (maize) starch in rice cake could be detected.
Studies on the relationship between antioxidative activity of rice hull and germination ability of rice seeds
Authors: Ramarathnam Narasimhan , Osawa Toshihiko , Namiki Mitsuo , Tashiro Tom
Published: October 2006

An investigation of the germination potentials of seeds of Indica and Japonica rice varieties revealed that while the long‐life rice seeds retained the germination ability even on storage for a year at 30°C, the germination ability of the short‐life rice seeds tended to decrease when stored beyond 6 months. The role of rice hull constituents in the preservation of the germination property during ageing of rice seeds was investigated with special emphasis on rice antioxidants. Antioxidative assay with chloroform‐methanol and methanol‐water extracts of hull, bran‐germ and grain fractions of two Indica and five Japonica rice varieties indicated that all of the seed varieties belonging to Indica and Japonica possessed a strong antioxidative activity in the hull fraction. Hull extracts of long‐life rice seeds showed relatively higher activities than those of short‐life rice seeds. In contrast, hull extracts of long‐life rice seeds had higher inhibitory effects on lipoxygenase activity than did those of short‐life varieties. Quantification of the natural antioxidants indicated that α‐tocopherol in rice oil to be present in the range of 318.3–450.1 μg g−1 oil while the amount of oryzanol in the hull, bran‐germ and grain fractions of rice was found to be 1.0–5.8, 95.4–279.8 and 3.0–9.4 μg g−1 sample respectively. The results, however, did not show any positive correlation between the amount of natural antioxidants in rice hull and germination potentials of rice seeds. The amount of total phenolic constituents in rice hull was found to range from 190–390 μg g−1 sample, the levels being far higher in long‐life rice seeds in comparison with the short‐life rice seeds. These values seemed to agree well with the germination data of the corresponding rice variety. The investigation revealed a strong influence of the level of phenolic constituents in rice hull on the storability of rice seeds.
The yeast flora of ensiled whole‐crop maize
Authors: Middelhoven Wouter J. , Franzen Mariëtte M.
Published: October 2006

The yeast flora in samples of 13 different whole‐crop maize silages was shown to be predominated by Candida krusei, C. lambica, Saccharomyces dairensis, S. exiguus, C. holmii or C. milleri. All these strains fermented glucose but, except for the latter three species, not sucrose, α‐trehalose or raffinose. Under conditions resembling those in silage, i.e. at pH 4.0 in the presence of a complex nitrogen source, all strains assimilated lactic and acetic acids. This result suggests that the predominant yeasts in silage should not be distinguished into lactate utilisers and lactate non‐utilisers. All strains, except those of Saccharomyces dairensis, tolerated acetic acid (5 g litre−1) and grew at pH 4.0 in a mineral salts medium containing lactic acid (10 g litre−1), acetic acid (5 g litre−1) and yeast extract (1 g litre−1). Growth in this medium was completely inhibited by the cationic detergent Arquad C33W (20 mg litre−1), propionic acid (5 g litre−1), benzoic acid (5 g litre−1) or salicylic acid (10 g litre−1).
The analysis of amino acids in fruit juices by high‐performance liquid chromatography
Authors: Peter J. Chaytor
Published: October 2006

A method is described for the rapid determination of amino acids in liquid foods by high‐performance liquid chromatography (h.p.l.c.). The method has proved itself simple and reliable in use and is intended to provide amino acid profiles within 30–40 min of receipt of sample. Method assessment is discussed and the results obtained on typical processed foods are presented.
Chemical and physical characteristics of phosphate rock materials of varying reactivity
Authors: Syers J. Keith , Mackay Alec D. , Brown Michael W. , Currie Lance D.
Published: October 2006

Several chemical and physical properties of 10 phosphate rock (PR) materials of varying reactivity were evaluated. These included North Carolina phosphate rock (NCPR), Sechura phosphate rock (SPR), Chatham Rise phosphorite (CRP), Arad phosphate rock (APR), Gafsa phosphate rock (GPR), North Florida phosphate rock (NFPR), Jordanian phosphate rock (JPR), Mexican phosphate rock (MPR), Nauru Island phosphate rock (NIPR), and Makatea Island phosphate rock (MIPR). Concentrations of As and Cd were highest in NCPR and U was higher in APR and CRP than in the other reactive PR materials. Because Cd and U can accumulate in biological systems, it may be necessary to direct more attention towards the likely implications of Cd and U concentrations when evaluating a PR for direct application. Three sequential extractions with 2% citric acid may be more useful for comparing the chemical solubility of PR materials, particularly for those containing appreciable CaCO3. For each particle‐size fraction from <63 to >500 μm, SPR was more soluble in 2% citric acid than was NCPR. The higher solubility of SPR than NCPR in 2% citric acid, 2% formic acid, and neutral ammonium citrate possibly results from a higher chemical reactivity rather than from any difference in the surface area presented for dissolution. The poor relationship obtained between surface area and the solubility of the PR materials in the three chemical extractants suggests that surface area plays a secondary role to chemical reactivity in controlling the solubility of a PR in a chemical extractant. A Promesh plot provided an effective method for describing the particle‐size characteristics of those PR materials which occurred as sands. Fundamental characteristics, such as mean particle size and uniformity, can readily be determined from a Promesh plot.
Pepino (solanum muricatum): Chemical composition of ripe fruit
Authors: Redgwell Robert J. , Turner Noel A.
Published: October 2006

Ripe pepino fruit (Solanum muricatum L. cv. ‘El Camino’) were analysed for water, sugars, non‐volatile organic acids, amino acids, starch, vitamin C, minerals and cell wall composition. The sugars consisted of sucrose, fructose and glucose with sucrose accounting for 50% of the total. Citric acid made up more than 90% of the non‐volatile organic acids. Malic acid and traces of quinic acid were also present. Aspartic acid accounted for 70% of the total free amino acids. Cellulose, pectin and hemicellulose represented 71, 17 and 11% respectively of the cell wall polysaccharides. The vitamin Clevel was higher than normally found in most fruits, including citrus. A limited study suggested that the major change during maturation was a continuous increase in the levels of sucrose, citric acid and the dicarboxylic amino acids.
Nutritional quality of acid‐precipitated protein concentrate from the Nigerian ‚red skin’︁ groundnut (Arachis hypogaea L.)
Authors: Ihekoronye Alfred I.
Published: October 2006

Groundnut protein concentrate (GPC) prepared by isoelectric centrifuging at pH 4 was subjected to treatment with 0–12M hydrogen peroxide in the same manner as is used to destroy aflatoxins. The protein solubility, in‐vitro digestibility, amino acid composition and enzymic protein efficiency ratio (E‐PER) were compared with those of untreated concentrate. The nitrogen solubilities were markedly lower at acidic pH but comparable to values obtained from untreated samples at alkaline pH; the digestibilities ranged from 71.4 to 92.1% in treated samples and from 73.7 to 98.0% in untreated samples. There was a marked reduction in the content of threonine, proline, cystine, methionine and tryptophan, which was reflected in the lower E‐PER value for the treated samples. Despite these changes, peroxide‐treated GPC is a potentially useful supplement to many cereal‐based Nigerian weaning foods and breakfast preparations.
Determination of the biological value of a protein source with a supposedly ideal amino acid balance (a.r.c. 1981) for the young pig (10 to 20 kg liveweight)
Authors: Moughan Paul J. , Smith William C. , Cornwell Julie K.
Published: October 2006

Fourteen entire‐male pigs of 16 kg mean liveweight were given a synthetic diet, the sole protein source of which comprised enzymically hydrolysed casein and free synthetic amino acids. The amino acid balance of the 80 g kg−1 crude protein diet was formulated to equal the Agricultural Research Council (1981) recommended ideal amino acid balance for the growing pig (20 to 90 kg liveweight). In two separate metabolism trials the biological value (BV) of the diet was estimated to be 0.86±0.012 (n=8) and 0.82±0.025 (n=5), respectively. Both BVs were significantly lower than unity, indicating that this dietary amino acid balance was less than ideal for the young pig.
Rapid method for determining total glucosinolates in rapeseed by measurement of enzymatically released glucose
Authors: Smith Clifford A. , Dacombe Clive
Published: October 2006

Glucosinolates were hydrolysed with endogenous myrosinase to liberate glucose by ball‐milling whole seed with water. Similar ball‐milling with acidified 40% methanol deactivated myrosinase and allowed free glucose in the seed to be measured separately. Extracts were filtered through activated charcoal paper to remove interfering phenolic compounds, and glucose was measured by a glucose oxidase/peroxidase colorimetric procedure. Correction was made for free glucose before calculating total glucosinolate content of the seed. The procedure was simple, reproducible and rapid (30 min) and the addition of exogenous myrosinase was unnecessary. It gave figures in excellent agreement with the more lengthy Sephadex micro‐column method and the proposed EEC reference procedure based on temperature‐programmed gas‐liquid chromatography of trimethylsilyl derivatives formed from enzymatically produced desulphoglucosinolates.
Nutritional assessment of defatted oil meals of melon (Colocynthis citrullus L.) and fluted pumpkin (Telfaria occidentalis hook) by chick assay
Authors: Nwokolo Emmanuel , Sim Jeong S.
Published: October 2006

Analytical data on fatty acid, amino acid and mineral content of defatted melon seed and fluted pumpkin seed are presented and discussed. Also discussed are experimental data on availability of amino acids and minerals in these meals. Defatted melon seed and fluted pumpkin seed have protein contents of 66.20% and 66.54%, respectively, with an excellent pattern of amino acids, containing higher levels of most essential amino acids (except lysine) than soya bean meal. Amino acid availability is high (melon seed 95.30%, pumpkin seed 93.12%) and similar to the level in soya bean meal (94.31%). Mineral availability is significantly lower in melon seed (53.63%) and soya bean meal (54.94%) than in pumpkin seed (58.84%). The potential for increased dietary utilisation of melon and fluted pumpkin meals and flours to meet the dietary needs of monogastric animals as well as human subjects is discussed.
Calculated molecular weight distribution for glutenin
Authors: Ewart John A. D.
Published: October 2006

The size distribution of linear glutenin molecules has been calculated using standard theory of high polymers.

If the degree of polymerisation (DP) is defined as the number ofsubunits in a molecule, the DP distribution is expressed by a single variable, b, the reciprocal of the number‐average DP. For a DP of i, the weight‐ and number‐fractions are, respectively, ib2(1−b)i−1. and b(1−b)i−1. The weight‐average DP is (2/b)−I. The distribution is identical with that produced by random degradation of an infinite molecule (b being the fraction of interchain disulphide bonds broken).

The distribution predicts that there would be a significant amount of low mol. wt material: this is so in practice, such material being soluble in aqueous ethanol.

The shape of a calculated curve corresponds, at least qualitatively, to those in the literature obtained by gel filtration when allowance is made for the mol. wt axis being on a logarithmic scale, for the longest molecules emerging together in the excluded peak and for diffusion.

These experimental curves show that monomers are not the commonest species by weight (unless half gliadin consists of monomeric glutenin). This implies that glutenin has a linear, not a branched, molecule.
Determination of silver in foods by neutron activation analysis
Authors: bin Ahmad Sujari Amat Ngilmi , Bowen Humphry J. M.
Published: October 2006

Silver has been determined in a number of foodstuffs by neutron activation analysis. The results range from <1 to 530 ng g−1 dry matter and are highly variable, suggesting that random contanination of samples may occur. Higher concentrations of up to 31 ug g−1 dry matter were found in wild fungi. From these results, supplemented by others, the British dietary intake is estimated to be 4.5 ug Ag day−1, which constitutes no hazard to human health.
Protein, amino acids and ascorbic acid in some cultivars of mango
Authors: Kohli Kanchan , Qadry Jamal S. , Ali Mohammed
Published: October 2006

The concentrations of protein in nine cultivars of mango ranged from 0.98 g 100 g−1 to 3.27 g 100 g−1 and of ascorbic acid from 14 mg 100 g−1 to 57 mg 100 g−1. There were variable concentrations of free amino acids: among the free amino acids, alanine, glutamic acid, histidine, isoleucine, proline and valine were present in all the varieties. The protein‐bound amino acids, present in all cultivars, included alanine, aspartic acid, arginine, cystine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tyrosine and valine. There is no evidence of the effects of variety and growing conditions on the composition of the fruit.
Protein co‐precipitates from milk and blood plasma: Preparation and investigation of some functional properties
Authors: de Haast Johannes , Morressey Patrick A. , Fox Patrick F.
Published: October 2006

Various processing methods were investigated for the production of milk and porcine blood plasma co‐precipitates. Factors considered included pH and temperature treatments as well as the ratio of milk to plasma proteins in mixtures of the raw materials. The recovery of protein in precipitates was measured and the following method was selected accordingly for further studies: pH adjustment of skim milk and blood plasma mixtures to pH 9.5, heating to 70° C, readjustment of pH to 9.5, holding for 3 min, cooling to 68°C, pH adjustment to 3–5, holding for 5 min, cooling to ambient temperature and final pH adjustment to 4.7. Two co‐precipitates (70/30 M/P and 30/70 M/P) were prepared from a 70:30 and a 30:70 mixture of skim milk (M) and blood plasma (P). Some of the functional properties of these preparations were measured and compared with those of total milk protein (TMP) and blood plasma precipitate (P) prepared by the same procedure as well as acid‐precipitated casein. The protein contents of preparations freeze‐dried at pH 7.0 varied between 91.5 and 92.3% and those freeze‐dried at pH 4.7 varied between 93.1 and 96.0%. The solubility profile and emulsifying capacity of the 70/30 M/P compared favourably with those of caseinate and TMP. The solubilities of 30/70 M/P and 100% P were, however, poor. The viscosity of solutions of 70/30 M/P was considerably higher than those of caseinate and TMP solutions. Water adsorption isotherms of protein preparations were constructed and are presented in graphical form. Precipitates freeze‐dried at pH 7.0 adsorbed more moisture than the same preparations freeze‐dried at pH 4.7. These differences were especially evident a water activities >0.8.
Changes in chemical composition of the kew cultivar of pineapple fruit during development
Authors: Kermasha Selim , Barthakur Nayana N. , Alli Inteaz , Mohan Nalin K.
Published: October 2006

The chemical composition of the Kew cultivar of Indian pineapple (Ananas cosmosus L.) was studied after 65 days (pre‐mature), 100 days (early mature), and 150 days (late‐mature) from flowering. The fruit was analysed for sugars, amino acids and minerals. Total soluble carbohydrates increased from 6.02 to 9.24%, and protein content decreased from 0.69 to 0.21%, during the fruit‐development process. The vitamin C content decreased from 20.4 to 11.1 mg 100 g−1 edible fruit during development. Fructose, glucose and sucrose together constituted approximately 5.0% (pre‐mature), 2.4% (early mature), and 1.2% (late‐mature) of fresh weight. The contents of iron, boron and zinc increased during development. The major minerals in the mature fruit were potassium (31.33 mg 100 g−1), phosphorus (3.13 mg 100 g−1), calcium (3.92 mg 100 g−1), sodium (2.63 mg 100 g−1), iron (3.22 mg 100 g−1), zinc (0.55 mg 100 g−l), and copper (0.06 mg 100 g−1) of fresh sample. The content of most amino acids decreased during development; only aspartic acid showed a considerable increase in the late‐mature fruit.