bluuebunny/crossref_metadata_2025 huggingface dataset:
Viscosity of locust bean (Ceratonia siliqua) gum solutions
Authors: Garcia‐Ochoa F , Casas J A
Published: October 2006

Viscosity of locust bean (Ceratonia siliqua L) gum solutions has been studied. Shear rate, gum concentration and measuring and solubilisation temperatures were varied and the corresponding influences analysed. The gum solutions showed pseudoplastic behaviour. Apparent viscosity decreased with increasing measuring temperature. A maximum in the viscosity with increasing solubilisation temperature was observed, and it was assumed that this behaviour was related to differences in the molecular weight of the molecules dissolving at various temperatures, which produced a different galactose/mannose ratio in the solution. This effect was checked by a solubilisation study.
Quantitative quality tests for frozen fish. Dimethylamine content as a quality criterion for frozen South African hake (Merluccius capensis and Merluccius paradoxus) fillets and mince stored at −5°C, −18°C and −40°C
Authors: De Koning Adrianus J , Mol Theodora
Published: October 2006

Hake (Merluccius capensis Castelnau and M paradoxus Franca) fillets and mince were frozen and stored in seven different tests at — 5°C, — 18°C and — 40°C. Samples were withdrawn periodically and analysed for dimethylamine (DMA) content and texture. A highly significant correlation was found between DMA content and texture. A statistical expression was calculated which allows prediction of the quality of the hake with regard to texture from its DMA content.
Role of seed lipids in Aspergillus parasiticus growth and aflatoxin production
Authors: Reddy M Janardhana , Shetty H Shekara , Fanelli C , Lacey J
Published: October 2006

Seeds of crops with differing lipid content (groundnut (Arachis hypogaea L), paddy (Oryza sativa L), sorghum (Sorghum bicolor (L) Moench), cowpea (Vigna unguiculata L Walp) and green gram (Vigna radiatus L Wilczek)) were screened for their ability to support growth and aflatoxin B1 (AFB1) production by Aspergillus parasiticus NRRL 2999. Groundnut, with the most lipids, supported greatest AFB1 production. With all crops except for sorghum and paddy, powdered seed material (PSM) supported more AFB1 production than their respective defatted powdered seed material (DPSM). When A parasiticus was grown on Czapek Dox agar amended with PSM and DPSM of different seeds with differing lipid contents, A parasiticus colonies were always larger on PSM‐ than on DPSM‐supplemented medium of the same seed. However, mycelial dry weight was only greater on media supplemented with groundnut, cowpea or green gram PSM. Growth and aflatoxin production by A parasiticus was also compared in Czapek Dox broth amended with seed coats, cotyledons and embryonic axes of groundnut kernels. The cotyledons of groundnut, with most lipids, supported the greatest production of AFB1. Apart from media supplemented with embryonic axes, PSM again supported more growth and AFB1 production than DPSM of the same portion of the kernel. Seed lipids thus seem important in determining growth and AFB1 production by A parasiticus.
Comparison of gas chromatographic volatile profiling methods for assessing the flavour quality of kenyan black teas
Authors: Owuor Philip O
Published: October 2006

A comparison is made of the various ratios used to quantify black tea aroma such as: ratio of sum of gas chromatographic peak areas of compounds eluting before linalool (3,7‐dimethyl‐1,6‐Octadien‐3‐ol) to those eluting after linalool (Wickremasinghe‐Yamanishi ratio); gas chromatographic peak areas of compounds imparting sweet flowery aroma (Group II volatile flavour compounds) to those imparting green grassy aroma (Group I volatile flavour compounds), Owuor's flavour index; ratio of the sum of gas chromatographic peak area of the terpenoids to non‐terpenoids, i.e. Mahanta ratio; and gas chromatographic peak area of linalool to E‐2‐hexena1, i.e. Yamanishi‐Botheju ratio.

The Wickremasinghe‐Yamanishi ratio and Owuor's flavour index showed a significant relationship, the Mahanta ratio showed a significant but poor relationship, and the Yamanishi‐Botheju ratio had no relationship with the tasters evaluation of Kenyan clonal CTC black teas. Similar results were obtained from orthodox black teas manufactured from different varieties.
Production of a yogurt‐like product from plant foodstuffs and whey. Sensory evaluation and physical attributes
Authors: Shirai Keiko , Gutierrez‐Durán Mercedes , Marshall Valerie M E , Revah‐Moiseev Sergio , García‐Garibay Mariano
Published: October 2006

A mixed substrate composed of soya milk, oat flour and dried cheese whey (820, 110 and 70 g kg−1 respectively) was heat treated (80°C, 20 min) and fermented using two different yogurt starters. Sensory evaluation was conducted in order to get the basic flavour profile and to assess the acceptability of the product. Unfermented mixed substrate and fermented milk were used as references. Two yogurt starter combinations were used. Some additives such as sugar and calcium were also assessed. The addition of an equal weight of milk to the mixed substrate, and flavours such as strawberry jam or honey, were tried as well. Acceptability of the mixed substrate was increased by fermentation and added sugar, milk and/or flavours. A suitable combination of strains was very important to get good acceptability of the fermented product.

Colour and syneresis were also evaluated. Heat treatment had very little influence on the colour of the mixed substrate. The mixture was less white and a little less green than milk. Syneresis was lower than that of a yogurt made from milk with 145 g litre−1 total solids.
Seed lipids of Sesamum indicum and related wild species in Sudan. The sterols
Authors: Kamal‐Eldin Afaf , Appelqvist Lars Åke , Yousif Gariballa , Iskander George Mina
Published: October 2006

Oil extracted from seeds of different varieties of the cultivated Sesamum indicum L and three related wild species, viz S alatum Thonn, S radiatum Schum & Thonn, and S angustifolium (Oliv) Engl, were analysed for their total unsaponifiables and for the contents and composition of the three sterol fractions (desmethyl, monomethyl and dimethyl sterols). The sterols were analysed after saponification by preparative TLC, capillary GC and GC‐MS of their TMS ethers. Oils from the wild species contained more unsaponifiable material (2.3‐2.4%) compared with the cultivated species (1.1‐1.3%). Considerable differences were observed in the total sterol contents and the relative proportions of the three sterol fractions in the oils from the four species studied. Sitosterol, campesterol, stigmasterol and Δ5‐avenasterol were the major desmethyl sterols in all four species. The monomethyl sterol fraction consisted primarily of obtusifoliol, gramisterol, cycloeucalenol and citrostadienol. Cycloartenol and 24‐methylene cycloartanol were the predominant dimethyl sterols. Variations in the composition of the three sterol fractions were observed between S indicum oils traditionally pressed by the camel‐driven expellers and laboratory extracted oils from the same seeds.
Effects of carbon dioxide on fermentation and aerobic stability of maize silage
Authors: Muck R E , Spoelstra S F , Van Wikselaar P G
Published: October 2006

The effects of carbon dioxide level (100% versus 20% v in nitrogen) during ensiling on microbial populations and subsequent aerobic stability were studied in whole‐crop maize silage. In five trials, fresh maize was chopped and ensiled in 10‐litre silos with the two different gas atmospheres. Changes in populations of lactic acid bacteria, acetic acid bacteria, enterobacteria, Bacillus spores and moulds were only slightly affected by carbon dioxide level. In four of the five trials, fermentation products and pH were unaffected by treatment. Yeast counts were altered by carbon dioxide level but not consistently. The yeast population in maize silage made from one source was inhibited by high levels of carbon dioxide whereas the opposite occurred in the silages from two other sources. Aerobic stability was inversely related to yeast population. In two other experiments, maize silage taken from a bunker silo was re‐ensiled in 700‐litre and 10‐litre silos, respectively, and the same two gas treatments were used. Carbon dioxide level had little effect on microbial numbers except yeast counts, which tended to be higher in the 20% v carbon dioxide environment. Little effect on aerobic stability due to treatment was noted in either experiment. High carbon dioxide levels do not appear to improve aerobic stability consistently.
Fatty acid composition of mexican pine nut (Pinus cembroides) oil from three seed coat phenotypes
Authors: Sagrero‐Nieves Lorenzo
Published: October 2006

Fatty acids from oils extracted from three seed coat phenotypes of Mexican stone pines (Pinus cembroides Zuc) growing in the central region of Veracruz State, Mexico, consisted of lauric (0‐4.8%), myristic (3.4‐9.1%), palmitic (6.4‐7.8%), stearic (3.1‐5.5%), oleic (36.7‐47.2%) and linoleic (32.9‐44.5%) acids. The differences between the phenotypes studied were statistically significant in their levels of myristic, oleic and linoleic acids.
The influence of non‐volatile constituents on the extraction of ethyl esters from brandies
Authors: Piggott John R , Conner John M , Clyne Janice , Paterson Alistair
Published: October 2006

Large numbers of volatile and non‐volatile components have been analysed and quantified in the search for an understanding of alcoholic beverage flavour, but little attention has been paid to interactions between these compounds. The extractability by dichloromethane of ethyl esters from a series of Cognacs showed a variation which was loosely related to the level of wood‐derived components present. When added to a redistilled brandy, potassium chloride had little effect on ester extractability, but sucrose, tannic acid and an oak extract significantly reduced the amounts of ethyl esters extracted. When a brandy was fractionated by high‐performance liquid chromatography, the fractions containing esters were associated with less desirable flavour notes, suggesting that part of the maturation process involves a reduction in availability of compounds giving rise to such characteristics.
In‐vitro protein and sulphur amino acid availability as a measure of bean protein quality
Authors: Marletta Luisa , Carbonaro Marina , Carnovale Emilia
Published: October 2006

The total and ‘available’ cystine and methionine, and the in‐vitro and in‐vivo protein digestibilities were determined in six varieties of Phaseolus vulgaris with different seed coat colours. Reactive cystine and methionine, evaluated by chemical methods after in‐vitro enzymic digestion, were taken as a measure of the availability of sulphur amino acids. Cystine ‘availability’ ranged from 43 to 51% and from 31 to 58% in raw and cooked samples, respectively, while methionine ‘availability’ was over 90%, except for the two red varieties (55% and 74%). No correlation was found between cystine and methionine ‘availability’ and in‐vitro protein digestibility. In‐vitro protein digestibility (76.6‐80.7%) showed a good correlation (r = 0.857; P < 0.05) with in‐vivo values (72.0‐80.9%). Amino acid score corrected for protein digestibility and for sulphur amino acids availability, as suggested by the Codex Committee on Vegetable Proteins, seems to predict accurately the biological quality of bean protein, as was shown when in‐vitro indices were compared with net protein utilisation and relative protein value.
Engkabang (illipe)—an excellent component for cocoa butter equivalent fat
Authors: Nesaretnam Kalanithi , Ali Abdul Razak Bin Mohd
Published: October 2006

This paper studies the physico‐chemical characteristics of the fats of three species of engkabang (illipe): Shorea macrophylla, Shorea mecistopteryx and Shorea singkawang, to assess their potential as cocoa butter replacer fats. A comparison of the solid fat content and fatty acid composition of these species with those of cocoa butter and a commercial sample of illipe (Shorea stenoptera), indicated that S macrophylla and S mecistopteryx could be used as cocoa butter replacer fats. S singkawang, however, had less potential in this area. The fat of S macrophylla species when further evaluated in dark chocolate formulations in blends with palm‐mid fraction, made an effective cocoa butter equivalent fat.
Effect of dextrans of differing molecular weights on the rheology of wheat flour doughs and the quality characteristics of pan and arabic breads
Authors: Ross Andrew S. , McMaster Graham J. , David Tomlinson J. , Cheetham Norman W. H.
Published: October 2006

Dextrans (α‐1‐6‐D‐glucans) with weight‐average molecular weights (Mw) ranging from 10 to 500 kDa were used at a rate of 20 g kg−1 (flour basis) in order to modify doughs made from flour of the Australian hard‐grained wheat cultivars Banks, Sunco and Hartog. Doughs containing dextran fractions with Mw below 100 kDa showed significant (P ± 0.01) reductions in Farinograph maximal consistency and significant increases in Farinograph development time. Additions of dextrans also resulted in significant increases in maximal resistance and significant reductions in extensibility when doughs were subjected to Extensograph testing. After addition of dextran fractions with Mw of 100 kDa or less, there were significant reductions in loaf volumes in pan bread of the cultivar Hartog manufactured by a rapid dough system and in pan bread of the cultivars Banks and Hartog made by a fermented dough system. Arabic bread supplemented with dextrans had poorer internal and keeping qualities, and reduced bread surface area, leading to significantly decreased quality scores. These observations are discussed in relation to possible interactions between neutral polysaccharides and other flour components.
Potato lectin activity assay based on hemagglutination
Authors: Patel C. P. , Willis T. W.
Published: October 2006

A quantitative method for the determination of potato lectin activity has been developed. In the method, lectin is incubated with an excess of red blood cells (RBC) in phosphate buffered saline at 25 °C. Maximum agglutination is reached within 60 min. Agglutinated RBC are then separated from nonagglutinated RBC by filtration. The agglutinated RBC remaining on the filter paper are then lysed and cluted using a solution of Triton X‐100. The hemoglobin content of the lysed RBC is measured at 415 nm. The number of agglutinated RBC is calculated from the hemoglobin value. One unit of lectin activity will agglutinate one million RBC.
Effects of abomasal infusions of sodium caseinate, soya‐protein isolate and a water extract of fish meal on the utilisation of nitrogen by dairy cows
Authors: Choung Jai‐Jun , Chamberlain David G.
Published: October 2006

A nitrogen‐balance study was conducted with four lactating cows in mid‐to‐late lactation given the following treatments in a 4 × 4 latin square design with 14‐day periods: (1) basal diet of grass silage and barley, (2) basal diet plus sodium caseinate into the abomasum, (3) basal diet plus soya‐protein isolate (SPI) into the abomasum, and (4) basal diet plus a water‐extract of fish meal (FE) into the abomasum. All infusions supplied 184 g day−1 of total amino acids but differed in amino acid composition. All infusions increased (P < 0.01) the output of nitrogen in milk relative to basal, the values being 72.6, 90.4, 84.5 and 84.9 (SED 2.6) g day−1 for basal, caseinate, SPI and FE respectively; caseinate yielded more milk‐nitrogen (P < 0.05) than the other infusions. Urinary nitrogen was increased by all infusions relative to basal (P < 0.05) but differences between infusions were not significant (P > 0.05); values were 136.1, 155.8, 159.5 and 167.2 (SED 6.2) g day−1 for basal, caseinate, SPI and FE respectively. Nitrogen retention was not significantly affected by treatment. Despite their differences in amino acid composition, SPI and FE produced similar responses in the pattern of utilisation of nitrogen.
Effect of feeding a high level of sugar in the diet for the last 12 days before slaughter on muscle glycolytic potential and meat quality traits in pigs
Authors: Fernandez X. , Tornberg Eva , Mågård M. , Göransson L.
Published: October 2006

The aim of this work was to study the effects of 500 g kg−1 sucrose diet and of type of food distribution (ad libitum or two meals daily without food restriction) during the last 12 days before slaughter on glycolytic potential (GP, an estimate of resting muscle glycogen content) in pig Longissimus dorsi (LD) muscle, and on meat quality traits in muscles LD and Biceps femoris. The pigs used were three‐way crossbred ((Yorkshire × Landrace) × Hampshire). Samples of LD were taken intra vitam, immediately before and after treatment, using a biopsy technique. Muscle metabolites, GP and meat quality traits such as pH, internal light scattering or drip loss did not vary significantly between the treatments. A significant decrease in GP was noted after feeding the conventional diet ad libitum. The lack of effect of the sugar diet on muscle glycogen content might be attributed to the overnight fast ( 15 h) preceding the second sampling. It was therefore hypothesised that sugar feeding has no significant long‐term effect on muscle glycogen stores. The pigs exhibited a wide individual variability in GP changes during the feeding period. Pigs fed the conventional diet showed a marked trend towards a decreased GP after 12 days. This decrease in GP might be attributed to a sampling date effect, the reasons for which remain unknown.
The effect of soil moisture on the proximate composition of bambara groundnut (Vigna subterranea (L) Verdc)
Authors: Brough S H , Azam‐Ali S N
Published: October 2006

Bambara groundnut seeds, produced under five levels of irrigation (0–300 mm range) in a suite of controlled‐environment glasshouses, were analysed for their proximate composition. There was no significant effect of water treatment on the seed composition. Mean values (g kg–1 DM) of dry matter, protein, starch, free sugars, non‐starch polysaccharides and lipids were 8.91, 2.53, 4.28, 0.15, 2.56 and 0.79, respectively. Bambara groundnut protein was deficient in the sulphur amino acids, methionine and cysteine but met the FAO requirements for all other essential and non‐essential amino acids. Of the non‐starch polysaccharides (NSP) of bambara groundnut, the ratio of insoluble to soluble fractions was 57:43. Cellulose accounted for 36% of the total NSP. Approximately 12.8% of the total NSP was resistant to acid and enzymic hydrolysis. This fraction was attributed to lignified seed coat material and low molecular weight phenolic compounds. Tannin complexes capable of precipitating 142.6 g BSA (bovine serum albumin) per kg seed and trypsin inhibitor activity (13 g kg–1 DM) were measured in all five bambara groundnut treatments. The presence of these anti‐nutrients may have implications for the bio‐availability of bambara groundnut protein.
The effects of ensiling whole crop maize with a multi‐enzyme preparation on the chemical composition of the resulting silages
Authors: Spoelstra Sierk F. , Van Wikselaar Piet G. , Harder Bram
Published: October 2006

An enzyme preparation containing cellulolytic, hemicellulolytic and amylolytic activities was added to whole crop maize before ensiling in laboratory or pilot‐scale silos. In the enzyme‐treated silages, 5–28% of the cell wall components were degraded. The reduction in starch contents relative to the control, ranged from 40 to 75%. Higher enzyme dosages and longer incubation periods increased the degradation. The enzyme‐treated silages contained high concentrations of ethanol (2–3 mol kg–1 DM) and higher yeast counts. Counts of enterobacteria and lactic acid bacteria did not differ. Levels of lactic acid were increased in the enzyme‐treated silages while acetic acid concentrations were similar. The starch in maize silage was degraded relatively easily by the amylase activity present in the enzyme preparation in comparison to the degradation of cell wall constituents. The liberated sugars were fermented to ethanol by yeasts. Probably the increased yeast count explains the observed lower aerobic stability of the enzyme‐treated silages.
Hemicellulosic cell wall carbohydrate monomer composition in Panicum amarum, P. amarulum and P virgatum accessions
Authors: De Ruiter J M , Burns J C , Timothy D H
Published: October 2006

Three taxa in the Virgata group of Panicum, ie Panicum amarum (Elliot) var amaruns (Hitch and Chase) P. G. Palmer, and P virgatum L, show potential as a ruminant feed. Accessions analyzing high and low in‐vitro dry matter disappearance (IVDMD) were selected from three morphological categories of short (grazing types), intermediate, and tall (hay types) from among these taxa. Significant structural carbohydrate variation existed among accessions and within plant and morphological categories. Significant differences in hemicellulosic monomer concentrations were also found for maturity stages and accessions differing in IVDMD. Total hydrolyzed hemicellulosic pentoses(arabinose+xylose) of plant parts were negatively correlated (r = –0.77, P ≤ 0.01) with IVDMD in contrast to hemicellulosic hexoses (galactose + glucose) which were positively related (r = 0.40, P ≤ 0.01). Similar significant (P ≤ 0.001) correlations for whole plant samples were r = –0.86 and 0.39, respectively. Of the hemicellulosic monomers, xylose and glucose accounted for most variation in IVDMD. The hydrolyzed hemicellulosic pentose fraction or a ratio between the xylose and glucose composition were indicators of IVDMD and would be useful in the selection of germplasm to develop improved Panicum ecotypes.
Kinetic study at different pH values of the oxidation process to produce ripe olives
Authors: García Pedro , Brenes Manuel , Vattan Thierry , Garrido Antonio
Published: October 2006

The kinetics of the oxidation process to produce ripe olives were studied. The sodium hydroxide solutions used for treating the ripe olives contain the same polyphenols as the olives treated with these solutions. These liquids could be utilized as model systems to study the oxidation reactions of polyphenols. However, oxidation of the olive surface was remarkably slower because the diffusion rate of oxygen into the flesh of the fruit was very low. Oxidation of the polyphenols (hydroxytyrosol and caffeic acid) in the sodium hydroxide solutions followed first‐order kinetics. The values of the constant for hydroxytyrosol were higher than those for caffeic acid and darkening of the liquids. Olive and solution colour were darker and oxidation rates increased with increasing pH.
Amino acid and total protein content of the edible mushroom Cantharellus cibarius (Fries)
Authors: Danell Eric , Eaker David
Published: October 2006

It is difficult to determine total protein content in fungi, mainly because chitin and other nitrogenous compounds interfere with total nitrogen analysis (eg Kjeldahl analysis) which is commonly used. Therefore, a few different methods have been compared, and total amino acid concentration and composition in the edible mushroom Cantharellus cibarius (Fries) have been analysed using one sophisticated and one rough method based on acid hydrolysis and ninhydrin. For fungal material, it is better to analyse total amino acids. Only 99 g kg−1 dry weight of C cibarius was protein which implies that former values based on total N analysis given in literature are 70–200% too high. The nutritional value of mushrooms should therefore not be over emphasised, even though the protein content is higher than that of most vegetables.
The polymorphism of diglycerides
Authors: Shannon R J , Fenerty J. , Hamilton R J , Padley F B
Published: October 2006

The polymorphism of 1,3‐dipalmitin, 1,2‐dipalmitoyl‐sn‐glycerol, 1.2‐dipalmitoyl‐rac‐glycerol has been examined by X‐ray diffraction, IR spectroscopy and Raman spectroscopy and differential scanning calorimetry. The respective spectra and thermographs are presented for these polymorphs. Optically active 1,2‐diglycerides exhibit very different thermal behaviour from the optically inactive 1,2‐diglycerides. A novel HPLC system was devised for the separation of the diglycerides.
Endogenous amino acid flow in the stomach and small intestine of the young growing pig
Authors: Moughan Paul J. , Marlies Leenaars Gerard Schuttetr
Published: October 2006

Endogenous ileal amino acid flows were determined in the young growing pig given an enzymically hydrolysed casein (EHC)‐based diet with subsequent treatment of the digesta by ultrafiltration. Comparison was made with endogenous excretions obtained from pigs fed an EHC‐based or a protein‐free diet but without treatment of the digesta. Ten entire male pigs of 15 kg liveweight were fed either an EHC‐based diet or a protein‐free diet, and samples of digesta were collected following euthanasia. The digesta from the EHC‐fed pigs were divided into two equal portions. One portion was untreated, and the second portion was ultrafiltered after centrifugation with the retentate (high‐molecular‐weight fraction) being added to the precipitate. Endogenous ileal amino acid flows were determined for the untreated digesta and for the digesta following the centrifugation plus ultrafiltration treatment. Except for arginine, glycine, leucine and phenylalanine, the endogenous amino acid flows were significantly (P < 0.05) higher for the untreated digesta than for the digesta following the centrifugation plus ultrafiltration treatment. Except for arginine, glycine, leucine and phenylalanine, the endogenous amino acid flows were significantly (P < 0.05) highter for the untreated digesta than for the digesta following the centrifugation plus ultrafiltration treatment. The pigs fed a protein‐free diet generally had lower amino acid flows than those fed the EHC‐based diet (ultrafiltration treatment). significantly (P < 0.05) so for lysine, aspartic acid, threonine, serine, glutamic acid, glycine, valine, isoleucine and leucine. The endogenous flows in different segments of the upper digestive tract of the young growing pig were also determined in the animals fed the protein‐free diet. The endogenous amino acid flow was highest in the second third of the upper digestive tract. There was a significant (P < 0.05) difference between the amino acid flows determined in the first and second thirds of the small intestine for most of the amino acids.
Nutrient composition of the hull‐less barley cultivar, condor
Authors: Edney M J , Tkachuk R. , Macgregor A W
Published: October 2006

Eleven grain samples of Condor, a two‐rowed, hull‐less barley cultivar. were analysed for concentrations of protein, starch, amino acids and fibre. Starch levels were found to be consistently higher than that of a covered barley and approached that of a hard spring wheat. Acid‐detergent fibre was found to be 70% lower in the hull‐less samples than in the covered barley or the wheat. The Condor samples showed a wide range of protein concentrations (12.5‐17.2% on a dry matter basis). The concentrations of arginine, cystine, isoleucine, lysine, methionine and threonine (percent dry matter basis) were consistently higher in the Condor barley samples assayed here than levels stated in the literature for barley. The concentrations (g (100 g protein)−1) of cystine (P < 0.01), lysine (P < 0.001) and threonine (P < 0.01) decreased significantly as protein increased. Isoleucine, methionine and tryptophan showed no such effect. Both glutamic acid and proline concentrations increased significantly (P < 0.01) as protein increased which suggested higher amounts of hordeins in high protein Condor barley.
Strawberry juice colour: The effect of some processing variables on the stability of anthocyanins
Authors: Bakker Johanna , Bridle Peter , Koopman Anja
Published: October 2006

The colour stability of juice and purées made from a mixture of two strawberry varieties, stored at + 20°C or at –20°C under aerobic and anaerobic conditions, was studied. High‐performance liquid chromatography and spectrophotometric analysis were used to monitor the changes in colour during storage. Pelargonidin 3‐glucoside comprised 80% of the total anthocyanin content. Four other pelargonidin‐based peaks were found, being 10.4%, 3.5%, 0.7% and 0.3% of the total and two cyanidin peaks were present, being 3.3% and 0.4% of the total. Clarification before storage caused considerable losses in the initial anthocyanin concentrations. Storage conditions (air versus nitrogen) did not influence the rate of loss of anthocyanins during storage or the formation of polymeric pigments. There were no losses in anthocyanins and no increase in the amount of colour measured at 510 nm due to polymers in samples stored at–20°C. Polymerisation occurred in the samples stored at + 20°C, especially in the clarified samples.
Strawberry juice colour: The effect of sulphur dioxide and edta on the stability of anthocyanins
Authors: Bakker Johanna , Bridle Peter
Published: October 2006

The loss of anthocyanins and the formation of colour due to polymeric pigments in juices and purées prepared from strawberries (variety Senga sengana) was studied during storage at — 20°C and + 20°C. Four different treatments were given to the samples immediately after milling: no additions, EDTA addition, sulphur dioxide addition, and a combination of sulphur dioxide and EDTA. The concentration of anthocyanins and the proportion of colour due to polymeric pigments were measured by high‐performance liquid chromatography and spectrophotometry. Losses in anthocyanins were very small during 10 weeks storage at –20°C and there was no effect of the treatment. The addition of sulphur dioxide slowed down the loss of anthocyanins at + 20°C, especially in the purées and correspondingly decreased the rate of polymeric pigment formation. Addition of EDTA had only a slight effect on colour stability.
Development of a simple pungency indicator test for onions
Authors: Thomas David J. , Parkin Kirk L. , Simon Philipp W.
Published: October 2006

Long‐day yellow onions differing in pungency were used to compare methods for appraisal of pungency. Pyruvate, an established indicator of pungency for Allium species, was determined by the lactate dehydrogenase and 2,4‐dinitrophenyl hydrazine methods. Thiosulfinate content, another indicator of pungency, was determined spectrophotometrically by monitoring the absorbance at 515 nm after reaction with N‐ethylmaleimide. Significant correlation (R2 = 0.871) existed between thiosulfinate content and pyruvate concentration. In addition, a modified N‐ethylmaleimide reaction was used to develop a simple pungency indicator test which adequately detected differences between bulbs. The color produced by this method was analyzed using a HunterLab reflectance colorimeter. The Hunter a value and saturation index (C) correlated with both thiosulfinate content and pyruvate concentration (R2 = 0.735–0.860). The procedure described provides the potential for screening of pungency of large numbers of Allium samples.
An evaluation of the aroma characteristics of malted barley by free‐choice profiling
Authors: Beal Andrew D , Mottram Donald S
Published: October 2006

Barley malt was sampled at six stages during the kilning process. The malts, ranging from green malt to crystal malt, were subjected to odour assessment, by a minimally trained panel, using free‐choice profiling, a descriptive sensory technique. The panel successfully discriminated between the samples. Their descriptions reflected the changes in odour profile of the malt during kilning. Green malt was described as having ‘fruity’, ‘hay‐like’ and ‘damp‐straw’ characteristics. The ‘fruity’ odours disappeared during kilning, as odours typical of dried grass or straw became apparent. These, and the ‘haylike’ odours, diminished as kilning temperature and time increased, being replaced by the ‘burnt’, ‘bready’, ‘malty’ and ‘chocolate‐like’ odours typical of the final crystal malt.
Oil quality characteristics and headspace volatiles of newly released groundnut (Arachis hypogaea L) cultivars
Authors: Jambunathan Ramamurthi , Sridhar Rudravarapu , Raghunath Kooram , Dwivedi Sangam L , Nigam Shyam N
Published: October 2006

Several groundnut (Arachis hypogaea L) cultivars developed by the International Crops Research Institute for the Semi‐arid Tropics (ICRISAT), and one local cultivar for use as a control were grown in the post‐rainy and rainy seasons at Patancheru, India. Free and bound lipids were extracted and their fatty acid compositions determined. Acid, peroxide, iodine and saponification values were determined. Flavour quality was evaluated using headspace analysis. The quantity of total lipids was significantly higher in the cultivars grown in the rainy season than those grown in the post‐rainy season and was higher in the ICRISAT cultivars than in the control in both seasons. Oleic (O) to linoleic (L) acid ratio was lowest in the chioroform‐methanol extract and highest in water‐saturated butanol extract. One ICRISAT line, ICGS 21, showed the highest O/L ratio in all lipid fractions in both seasons. Among the flavour components, n‐methyl pyrrole, associated with an objectionable musty flavour, was present in very high concentration in all the cultivars.
Endogenous lysine and other amino acid flows at the terminal ileum of the growing pig (20 kg bodyweight): The effect of protein‐free, synthetic amino acid, peptide and protein alimentation
Authors: Butts Christine A , Moughan Paul J , Smith William C , Carr David H
Published: October 2006

Twenty‐four crossbred pigs of 15 kg initial bodyweight were fed four semi‐synthetic diets for 10 days according to a completely randomised design. The study aimed to determine the effects of state of body nitrogen balance and the presence of dietary peptides and protein in the digestive tract on the excretion of endogenous amino acids from the ileum of the pig. Endogenous lysine excretion was determined for pigs given a protein‐free (PF) diet, an enzymically hydrolysed casein‐ (EHC), a zein‐ (ZN) or a synthetic amino acid‐ (SAA) based diet. Digesta from the EHC‐fed animals were centrifuged and ultrafiltered after collection and the precipitate plus retentate fraction was used to determine the endogenous flows. Such processing excludes unabsorbed dietary amino acids from the measure of endogenous loss. ZN is naturally deficient in lysine and tryptophan and these two amino acids were omitted from the synthetic amino acid‐based diet to allow direct measurement of endogenous lysine flow. Pigs given the ZN and SAA diets received free lysine and tryptophan orally throughout the study except for the final 2 days of the study, when these amino acids were infused intravenously. Endogenous flows for amino acids other than lysine were determined for pigs given the PF and EHC diets. On the final day of the study the pigs were given their daily dietary allowance hourly and killed 10 h after the start of feeding. Digesta were collected from the terminal ileum (20 cm anterior to the ileo‐caecal junction) and endogenous flows were determined by reference to the marker chromic oxide. The mean endogenous ileal lysine flows for the ZN‐ and EHC‐fed pigs were not significantly different (overall mean, 419 mg kg−1 dry matter intake), but were higher (P < 0.05) than those for the PF‐ and SAA‐fed pigs (overall mean, 268 mg kg−1 dry matter intake) whose mean flows were not significantly different from each other. The mean endogenous ileal flows for amino acids other than lysine were higher (P < 0.05) for the EHC‐fed pigs compared to the animals on the PF diet, except for proline, glycine and arginine. The similar endogenous ileal lysine excretion for pigs receiving a SAA‐based diet and in positive body nitrogen balance, and PF‐fed pigs in negative body nitrogen balance, indicates that negative body nitrogen balance per se does not lead to a lowered endogenous ileal excretion. It would appear, however, that the presence of dietary peptides or protein in the gut increases amino acid excretion at the terminal ileum above that found with PF or SAA alimentation. Consequently, endogenous ileal amino acid flow in the pig may be underestimated when determined by the traditional PF method.
Multidimensional scaling as a method to correlate sensory and instrumental data of orange juice aromas
Authors: Vélez C. , Costell E , Orlando L , Nadal M I , Sendra J M , Izquierdo L
Published: October 2006

Changes of orange juice aromas due to storage time and temperature were studied through sensory detection of differences between samples, and by gas chromatographic analysis of 38 volatile constituents. Multidimensional scaling was applied to sensory and instrumental data prior to correlation analysis. Absolute concentrations of volatile constituents were not correlated with sensory data but higher correlations were observed with normalised analytical data. Thus, correlation coefficients were respectively 0.47 and 0.74 when considering (i) relative concentrations of all volatiles, by expressing the concentration of each constituent in a sample as a proportion of the maximum observed concentration of this constituent; and (ii) relative concentrations of only those constituents showing significant (95% level) changes due to storage length or temperature.
Crystallization kinetics of emulsified triglycerides
Authors: Özilgen S. , Simoneau C , German J B , McCarthy M J , Reid D S
Published: October 2006

Nucleation and crystal growth process of triglycerides in water emulsions composed of trimyristin (c l4:0) admixed with 0, 40, and 80 ml litre−1 trilaurin (c 12:0) (expressed v per total v emulsion) were followed with NMR (nuclear magnetic resonance) and DSC (differential scanning calorimetry). Mathematical analysis of the time dependence of the phase changes and thermal data distinguished two distinct ‘apparent’ kinetic phases. These phases were tentatively referred to as nucleation and crystal growth. With 40 and 80 ml litre−1 trilaurin (NMR data at 293 K) nucleation and crystal growth phases of trimyristin were simulated with zero order and second order rate expressions, respectively. Relative to these mixtures, pure trimyristin nucleation was delayed in the initial phase, but crystal growth occurred with fast homogeneous nucleation and slower growth in the second phase. Statistical analyses indicated that homogeneous nucleation similarly occurred when 40 or 80 ml litre−1 trilaurin was admixed with trimyristin. NMR resolution made it possible to follow the crystallization phenomena in different locations of the crystallization vessel effectively in situ and undisturbed. Statistical analyses in this case revealed a significant trilaurin‐location interaction confirming that the rate of nucleation processes was affected both by the concentration of trilaurin and the heat transfer properties of the sample and vessel. The time‐location interactions were not significant, confirming the hypothesis that in the absence of tilaurin, zero order nucleation did not occur in the first phase.
A new process for preparing transparent alkalised duck egg and its quality
Authors: Su Hou‐Pin , Lin Chin‐Wen
Published: October 2006

When fresh duck (Anas plotyrhyncus) eggs (pH 8·0–8·5) are heated, their albumen develops a turbid gel. Through appropriate alkalisation (pH 11·5–12·8), the gel's transparency can be increased. The transparency of the heated duck egg‐white is affected by pH value, heating temperature, heating rate and salt concentration. This research deals with the process for preparing the transparent alkalised duck egg and the change in its quality when stored. If fresh duck eggs are pickled in a solution of 42 g NaOH+50 g NaCl litre−1 (25·3°C) for 8 days, removed, put in a water bath and heated at 70°C for 10 min they become transparent, their hardness and penetration increasing with storage. Total bacterial count and volatile basic nitrogen also increase with storage. The total bacterial count and the volatile basic nitrogen were 4·6 × 106 cfu g−1, 0·32 mg g−1 when stored at a temperature of under 25°C for 4 weeks, respectively.
Hesperetin: A marker of the floral origin of citrus honey
Authors: Ferreres Federico , García‐Viguera Christina , Tomás‐Lorente Francisco , Tomás‐Barberán Francisco A
Published: October 2006

Seventeen flavonoid aglycones were identified in various experimental and commercial citrus honey samples by HPLC analysis. The flavanone hesperetin was detected in all samples. This flavanone was not detected in any of the honey samples, from diverse floral origin (including rosemary, lavender, sunflower, almond, sweet chestnut, white clover, Erisarum, Robinia, Rhododendron, Tilia, Prosopis, Eucalyptus and Calluna honeys) previously investigated. The analysis of the flavonoids present in orange nectar revealed that the flavanone hesperidin (hesperetin‐7‐rutinoside) was the major flavonoid detected and, therefore, this should be the main source of the hesperetin found in citrus honey. Hesperetin should be produced by hydrolysis of hesperidin by the bee enzymes present in honey. These results suggest that hesperetin could be used as a marker for the botanical origin of citrus honey.
D‐Lysine, alloisoleucine and lysinoalanine in supplementary proteins with different lysine availabilities
Authors: Davies Richard L
Published: October 2006

D‐Lysine, alloisoleucine and lysinoalanine were determined in 16 commercial protein supplements on which lysine availability had been measured by slope‐ratio assay with pigs and by chemical dinitrophenylation. About 2.5% of lysine was racemised by protein hydrolysis in 6 M HCl. Only three of 10 samples with poor lysine availability by slope‐ratio assay contained significantly more D‐iysine than control proteins (P < 0.01). D‐Lysine was not significantly correlated with lysine availability by either method; nor did it improve the poor correlation between the slope‐ratio assay and dinitrophenylation. The highest level of alloisoleucine was less than 14% that of isoleucine. In all proteins except skim milk powder lysinoalanine occurred at 0.3% or less of the corresponding lysine level. Neither alloisoleucine nor lysinoalanine was related to lysine availability.
Gravimetric determination of tannins and their correlations with chemical and protein precipitation methods
Authors: Makkar Harinder P S , Blümmel Michael , Borowy Norbert K , Becker Klaus
Published: October 2006

Abstract. A method for gravimetric determination of tannins based on binding with insoluble polyvinylpyrrolidone (PVP) is presented. The gravimetric method gives the absolute amount of tannins and avoids problems of standards associated with spectrophotometric methods. The method was applied to nine browse and tree leaves. The values obtained correlate significantly with tannins determined spectrophotometrically, protein precipitation capacities and protein precipitable phenotics. This method together with other tannin assays will be useful in nutritional studies. The present study also demonstrates the different behaviour of tannic acids from different commercial sources towards PVP suggesting the presence of different moieties in tannic acids from different commercial sources and even among batches from the same source thereby affecting the results obtained using the spectrophotometric methods. Use of well‐defined tannic acid as a standard in spectrophotometric methods is suggested which will allow meaningful comparison of values obtained from different laboratories.
Evaluation of rapeseed meals in broiler chicks: Effect of iodine supply and glucosinolate degradation by myrosinase or copper
Authors: Schöne Friedrich , Jahreis Gerhard , Richter Gerhard , Lange Reinhard
Published: October 2006

In rapeseed meals (RSM) of a conventional (c) or a newly bred (n) variety 117 or 44 mmol glucosinolates and glucosinolate degradation products per kg dry matter were detected. Soaking meals in aqueous myrosinase or copper sulphate solution and subsequent drying reduced the content of antinutrients by more than 90%. Broiler chickens were fed (i) a glucosinolate‐free diet, or this diet in which half the soybean meal was replaced by RSM of various origins and treatment; (ii) untreated cRSM; (iii) cRSM treated with myrosinase: (iv) cRSM treated with Cu (v) untreated nRSM; or (vi) nRSM treated with myrosinase. These diets were administered with or without supplementary iodine. Chickens receiving the iodine‐deficient diets with myrosinase‐treated RSM showed growth depression, incomplete feathering, leg injuries and severe goitre. In the serum T4 could not be detected. Giving myrosinase‐treated RSM plus iodine, or giving other RSM diets irrespective of iodine administration, no growth depression was observed. RSM diets without iodine dosage markedly increased thyroid weight: there were no differences between the RSM variants. In contrast to the treatment with myrosinase, in the sera of the chickens fed on untreated RSM or RSM treated with copper T4 could be detected, suggesting that in iodine‐deficient conditions differences in serum T4 concentration between RSM groups indicate a differing anti‐thyroid activity. With iodine supplementation the RSM had a significant effect on thyroid weight. The largest thyroids (five‐fold heavier) were in the animals with myrosinase‐treated cRSM. The untreated cRSM and the nRSM trebled or doubled the thyroid weight, and the myrosinase‐treated nRSM trebled it. The thyroid weight of chicks fed cRSM treated with copper did not differ significantly from the glucosinolate‐free control. There was evidence that heating the myrosinase‐treated RMS produced anti‐thyroid compounds; these should be identified in further investigations.
Effect of carbon dioxide on the inactivation of florida spiny lobster polyphenol oxidase
Authors: Chen Jan S , Balaban Murat O , Wei Cheng I , Gleeson Richard A , Marshall Maurice R
Published: October 2006

Florida spiny lobster (Panulirus argus) polyphenol oxidase (PPO) exposed to CO2 (1 atm) at 33, 38, and 43°C showed a decrease in enzyme activity with increased heating time. Enzyme inactivation by CO2 was faster for PPO heated at 43 than at 33 or 38°C. Inactivation kinetics revealed PPO was more labile to CO2 and heat in the range 33–43°C than to heat alone. Kinetic data also revealed that CO2, in addition to pH changes, was involved in the loss of PPO activity. Studies using get electrophoresis showed no differences in protein patterns and isoelectric point between CO2‐treated and non‐treated control. The pH of CO2‐treated PPO stock solution was brought back from 5.4 to 8.0 after 6 weeks of frozen‐storage and no enzyme reactivation was observed.
Tocopherol and tocotrienol compositions of raw table olive fruit
Authors: Hassapidou Maria N , Manoukas Athanasios G
Published: October 2006

The tocopherol (Tp) and tocotrienol (Tt) compositions of raw Greek olive fruit pericarp were determined by high‐performance liquid chromatography. The following four types of fruit collected from three main varieties of olive trees were analysed: ‘Conservolea’ (green), ‘Halkidiki’ (green), ‘Conservolea’ (black) and ‘Calamon’ (black). α‐Tp was found to be the predominant Tp in all types. The variety and stage of maturity influenced the Tp and Tt composition. β‐Tp and α‐Tt were found only in trace quantities in green olives. The same was true for α‐Tp in all types and γ‐Tp in ‘Conservolea’ (green). The calculated α‐Tp equivalents (Tp and Tt compositions expressed as α‐Tp according to their relative biological activities) were 21·6, 29·7, 36·8 and 39·4 μg g−1 pericarp or 138, 132, 189 and 196 μg g−1 lipid for ‘Conservolea’ (green), ‘Halkidiki’ (green), ‘Conservolea’ (black) and ‘Calamon’ (black), respectively.