bluuebunny/crossref_metadata_2025 huggingface dataset:
The formation of thearubigin‐like substances by in‐vitro polyphenol oxidase‐mediated fermentation of individual flavan‐3‐ols
Authors: Opie Shaun C , Clifford Michael N , Robertson Alastair
Published: November 2006

An enzymic in‐vitro model tea fermentation system has been used in combination with gradient elution reversed‐phase high‐performance liquid chromatography to study the formation from individual fiavan‐3‐ols of resolvable and unresolvable thearubigin‐like substances. It has been found that in 30 min at pH 5.6 tea polyphenol oxidase (EC 1.14.18.1) produces a distinctive range of resolvable thearubigin‐like products from each flavan‐3‐ot substrate examined ((+)‐catechin, (−)‐epicatechin, (−)‐epigallocatechin, (−)‐epicatechin gallate and (−)‐epigallocatechin gallate). However, (−)‐epicatechin, and to a much lesser extent (+ )‐catechin, were the only flavan‐3‐ols converted to an unresolvable thearubigin‐like hump under these conditions. In addition, it was demonstrated that varying the pH of incubation in the range 5.0–6.0 had little effect on the profile of products obtained from the simple catechins, but a pronounced effect in the case of the gallocatechins. It is concluded that the combination of (−)‐epicatechin and polyphenol oxidase is the simplest model of tea fermentation that can be used to generate in quantity thearubigin‐like materials for structure elucidation.
Characterisation of monoclonal antibodies against β‐conglycinin from soya bean (Glycine max) and their use as probes for thermal denaturation
Authors: Plumb Geoffrey W , Lambert Nigel , Mills E N Clare , Tatton Marcus J , D'Ursel Christopher C M , Bogracheva Tatiana , Morgan Michael R A
Published: November 2006

A panel of four monoclonal antibodies (Mabs) was raised against β‐conglycinin, the 7S globulin from soya bean. The antibodies were characterised by using direct and competitive enzyme‐linked immunosorbent assays (ELISAs), immunoblotting procedures and by analysis of subunit fractions obtained after anion exchange chromatography. All the Mabs were specific for β‐conglycinin, recognising the acidic α‐and α‐subunits. One of the Mabs (IRFN 0089) was used to probe the structural changes that take place during thermal denaturation of β‐conglycinin. A two‐site ELISA was developed to observe structural changes in β‐conglycinin with heating. Antibody recognition of heated conglycinin increased with temperature reaching a maximum at 65°C; β‐conglycinin heated to this temperature was recognised three‐fold better than unheated β‐conglycinin. At a higher temperature (65–95°C) β‐conglycinin immunoreactivity remained at least two‐fold higher than that of the unheated protein. Differential scanning calorim‐etry data showed the maximum binding of Mab 0089 to correspond with the thermal transition of the β‐conglycinin molecule. The use of the panel of antibodies as structural probes is discussed together with further possible applications of this technology in food chemistry.
Fruit yield of field‐grown pear Pyrus communis (L) exposed to different levels of rain acidity in tuscany
Authors: Rinallo C , Modi G
Published: November 2006

The effects of simulated acid rain and natural rainfall on the pear cultivar Doyenne du Comice were studied in field experiments in Tuscany. Groups of trees were exposed to natural rainfall, or shielded and treated once weekly with 6 mm applications of one of three simulated rain treatments (pH 5·6, 4·0 and 3·0) or with deionised water (pH 6·5), during the prebloom to harvest period (March‐August) of 1991 and 1992. Increasing the concentration of acid sprays reduced the percentage of fruit harvested, fresh weight, dry weight, mineral concentrations in the pulp, and the pH of the juices; and increased heavy metal concentrations, total acidity, and nitrogen content. Fruits treated with the more acidic sprays also showed necrotic spotting. The effects of the pH 5·6 spray and natural rainfall were similar and mostly not significant, though lead and cadmium levels were significantly higher with natural rainfall exposure than with the pH 5·6 spray. These findings suggest that a further reduction in natural rainfall pH in Tuscany could have serious consequences for pear yield and quality.
Influence of crop management factors on chipping potato maturity and storage processing performance
Authors: Herrman Timothy J , Shafii Bahman , Love Stephen L , Dwelle Robert B
Published: November 2006

Russet Burbank, Norchip, and Gemchip potatoes were grown under three nitrogen fertilizer levels to study the relationship between physical/physiological maturity components and long‐term storage processing performance. Potatoes from all treatment conbinations were physiologically mature for processing (ie sucrose less than 1.5 mg g−1 tuber fresh weight basis) at harvest while physical maturity differences (periderm shear strength, vine appearance and tuber size) were evident during the growing season and harvest. A quadratic regression model, using date and (date)2 as regressors, provided the best description for potato chip color variation over a 13‐month storage period compared to linear, logarithmic, and higher order polynomial models. The optimal processing date (date in which the lightest chip color was predicted to occur during storage) for each nitrogen fertilizer by cultivar treatment combination was correlated with field maturity components. Russet Burbank and Gemchip potatoes that were less physically mature, indicated by vine appearance and periderm shear strength, resulted in optimal processing dates later in the storage season. Tuber size was negatively correlated with optimal processing date for Norchip tubers. These results suggest that physical and physiological maturity measures taken at or shortly before harvest may augment chemical maturity data for the purpose of selecting potato lots for long‐term storage.
Natural decoloration, composition and increase in dietary fibre content of an edible marine algae, Ulva rigida (Chlorophyta), grown under different nitrogen conditions
Authors: Lahaye Marc , Gomez‐Pinchetti Juan‐Luis , del Rio Miguel Jimenez , Garcia‐Reina Guillermo
Published: November 2006

The colour, dietary fibre content and characteristics of the edible marine green algae, Ulva rigida, were investigated in relation with the nitrogen content of the algal culture medium. Colour brightness decreased and total nitrogen of the algae increased in nitrogen‐enriched conditions. When nitrogen‐enriched seaweeds were grown again in normal seawater for 10 days, colour brightness increased and total nitrogen concentration fell. Total dietary fibre content of the wild and nitrogen enriched algae were close (∼38.0% DW) but increased markedly when the nitrogen‐rich plants were cultured in normal sea‐water (54.4% after 10 days). Soluble fibre were xylorhamnoglucuronan sulphate (ulvan) with close molar compositions for all the seaweed samples. Insoluble polysaccharides were composed of glucose, xylose, uronic acid, rhamnose and sulphate which molar proportions varied for the different algal samples. The soluble fibre intrinsic viscosity and the water holding capacity of insoluble fibre were not markedly affected by the growth conditions. This report demonstrates that edible seaweed aquaculture provides an alternative or a complement to post‐harvest transformations of seaweeds to modify organoleptic and nutritional characteristics.
Composition and in‐vitro digestibility of carbohydrates of wheat plants harvested at bloom and soft‐dough stages
Authors: Ben‐Ghedalia Daniel , Kabala Amos , Miron Joshua
Published: November 2006

Wheat plants (Triticum aestivum) were harvested at the bloom and soft‐dough stages, separated into leaves + sheaths, stems and spikes, and the effect of stage of maturity on neutral detergent fibre (NDF) composition and degradability was studied, the accumulation of starch in the spikes compensated for the decrease in the degradability of NDF polysaccharides so that the in‐vitro digestibility of the organic matter (OM) was not changed between the bloom and soft‐dough stages. Minor compositional changes occurred in the NDF of the various botanical fractions which can hardly explain the drop in NDF degradability with maturity. There was a decline in the ratio of hemicellulose to lignin, and the changes in NDF‐monosaccharide degradability were probably related to the extension of covalent bonding between those matrix components during maturation. Irrespective of botanical fraction and maturity stage, NDF xylose was less digestible than NDF glucose. Between bloom and soft‐dough stages there was an increase of 36% in the yield of digestible OM.
Application of aged egg in enabling increased substitution of sucrose by litesse (polydextrose) in high‐ratio cakes
Authors: Rosenthal Andrew J
Published: November 2006

Previous reports show that replacing sucrose by polydextrose in cakes leads to an elevation of the starch gelatinisation temperature such that it no longer coincides with the egg protein denaturation transition. It is known that as eggs age, the ovalbumin transforms to S‐ovalbumin with a higher denaturation temperature. Linking these observations led to the hypothesis that baking reduced‐sugar cakes with aged eggs might bring the starch gelatinisation into proximity of the protein denaturation thereby improving the final texture. Baking trials and instrumental texture evaluations of the resulting high‐ratio cakes were carried out with fresh egg and egg that had been aged at 37°C for 3, 7 and 14 days. Texture changes that do exist are principally related to differences in the cake crumb density and crumb springiness.
Predictive model for grain cracking in terms of rice plant and panicle morphology derived from multivariate analysis
Authors: Raju G N , Chand Nagin , Bhashyam M K , Srinivas T
Published: November 2006

Rice plant and panicle morphology in relation to grain cracking were studied in 17 varieties at four stages of maturity. The data were subjected to principal components analysis in order to identify structure within the data and reduce dimensionality. The first four factors collectively accounted for 72% of the trace. The first factor was dominated by yield and biomass related attributes, and the second with percentage cracked grains and grain moisture‐III stage. The projection of varieties onto the planes defined by the first, second, third and fourth factors reflected scattering of varieties over all the quadrants indicating desirable wide variations in the varieties studied, and the results could be generalised. The discussions mainly centred on grain cracking which was primarily influenced by plant height, panicle length, grains/panicle, sequence of grain maturity and the microenvironments—particularly towards the last stages of maturity. Predictive models in terms of the above attributes explained more than 96% of cracking. The role of agronomic practices in controlling grain cracking is discussed. It is indicated that dwarf plants influenced by microenvironment need different panicle morphology and physiological sequence to minimise cracking as compared to tall plants which generally escape the influence of microenvironment.
Impact of genotype, crop age and planting season on the breadmaking and gelatinisation properties of cassava (Manihot esculenta Crantz) Flour
Authors: Defloor I , Leijskens R , Bokanga M , Delcour J A
Published: November 2006

The breadmaking potential of cassava flour (in cassava flour/defatted soya flour/glyceryl monostearate recipes (80/20/3, w/w/w)) is not merely dependent on the age of the crop at harvest, but also on the season of planting and time of harvesting. Effects of cassava genotype are less important for determining bread quality. In flours obtained from crops harvested at different times after planting, differences in gelatinisation onset temperatures measured by Brabender visco‐amylography and by differential scanning calorimetry accounted for the observed differences in breadmaking potential of cassava flour of single genotypes and planting seasons to some extent. Cassava starch produced breads with a drier crumb, with a finer structure and with a more bulged crust than cassava flour. Differentiations in baking performance between starch samples, although smaller, still existed. This showed that the breadmaking potential of cassava flour samples is determined both by the starch and by the non‐starch fractions. Differentiation of cassava samples in the breadmaking process did not occur at the mixing or fermentation stage of the batter but during baking.
Short‐chain fatty acid content and pH in caecum of rats fed various sources of starch
Authors: Berggren Anna M , Björck Inger M E , Nyman E Margareta G L , Eggum Bjørn O
Published: November 2006

Caecal pH and contents of short‐chain fatty acids (SCFA) were registered in rats fed three potential sources of resistant starch (RS); raw pea starch, raw potato starch, and an RS‐enriched preparation obtained from wheat starch by autoclaving and enzymatic incubation. Small intestinal digestibility and delivery of RS to the hind‐gut in the case of raw starches were determined by analysis of faecal starch in animals treated with antibiotics to prevent hind‐gut fermentation. RS content in the RS‐enriched preparation was determined as total starch remaining in an enzymatic gravimetric dietary fibre residue. The fermentability of RS was estimated from the faecal recovery of starch in normal animals with intact hind‐gut microflora. Approximately 35 g per 100 g and 32 g per 100 g were RS in the case of raw potato starch and the RS‐enriched preparation, respectively, versus only 1 g per 100 g in the case of raw pea starch. The caecal pH decreased with all test diets, being most significant with raw potato starch. SCFA production and faecal bulking were negligible with raw pea starch, whereas both raw potato starch and the RS‐enriched preparation significantly increased these parameters. The fermentability of RS in raw potato starch and the RS‐enriched preparation was similar, or about 60–70%. If calculated on basis of fermented amount, RS in raw potato starch was more potent in generating SCFA (49 μmol g−1) than in the RS‐enriched preparation (19 μmol g−1). RS in raw potato starch also displayed the highest faecal bulking capacity. In fact, the faecal dry weight increased more than expected merely from delivery of RS. The relative proportion in caecal contents of acetic‐, propionic‐ and butyric acid was 70, 17 and 8%, respectively, with no significant differences between the three sources of RS.
Effects of protein from different sources on the characteristics of sponge cakes, rice cakes (apam), doughnuts and frying batters
Authors: Mohamed Suhaila , Lajis Siti Mawar Md , Hamid Norhashimah Abdul
Published: November 2006

Sponge cakes containing total substitution of whole egg with egg yolk had the largest volume, best texture, highest moisture, colour and flavour compared with all other cakes. Cakes made with total substitution of other proteins had smaller volumes than the control, while those made with egg white had the lowest moisture. Cakes made with whey powder had the tenderest texture. Doughnuts made with protein other than gluten had reduced oil absorption compared with the control. Doughnuts containing whey or skimmed milk had the most desirable flavour; this may be attributed to the presence of lactose. Gluten doughnuts were most disliked because of their hard texture and pale colour. Doughnuts made with total substitution of whole egg with egg white had good texture and low oil absorption. Skimmed milk powder was best for the expansion and texture of chemically leavened rice cakes (apam), while egg white produced the best expansion for yeast‐leavened rice cakes, compared with the other proteins studied. The protein that produced the most desirable textures in yeast‐leavened rice cakes in order of merit were skimmed milk powder, egg white and egg yolk.

Whey, skimmed milk powder and gluten helped improve the crispiness of frying batters. Ovalbumin did not affect the crispiness but significantly reduced the oil absorption of the frying batters. Addition of proteins other than whey and ovalbumin, increased the oil absorption of frying batters.
Relationships between minerals in Australian brown rice
Authors: Marr Katrina M , Batten Graeme D , Blakeney Anthony B
Published: November 2006

Ninety samples of brown rice cv Amaroo, which has occupied over 50% of the area sown to rice in southern Australia in the last two seasons, were collected from the rice growing regions of southern Australia at the end of the 1991–1992 season. The samples were analysed for total nitrogen using the Kjeldahl technique, and for P, K, S, Mg, Ca, Na, Al, Cu, Fe, Mn, Mo and Zn using inductively coupled plasma emission spectroscopy. The analysis of concentrations of elements show that Mn concentrations in Australian rice were higher and Ca concentrations lower than typical values reported for brown rice grown in other countries. For all other elements the concentrations had a similar range to those reported for overseas rice. Highly significant correlations were found between the major nutrients P, K and Mg, and also N and S. The Mg to K ratio ranged from 1·3 to 1·6 which indicates that, if Japanese criteria are used, the taste/stickiness quality within this cultivar of Australian rice could vary from undesirable to highly desirable.
Effectiveness of density segregation and sodium carbonate treatment on the detoxification of Fusarium‐contaminated corn fed to growing pigs
Authors: Rotter Roland G , Rotter Barbara A , Thompson Brian K , Prelusky Dan B , Trenholm H Locksley
Published: November 2006

The effectiveness of using rinsing, density segregation or 0.1 M sodium carbonate treatments of Fusarium‐contaminated corn containing deoxynivalenol (DON) and zearalenone were tested both chemically and by feeding the material to growing pigs. Uninfected and Fusarium graminearum‐inoculated corn (containing 40.3 mg DON and 0.94 mg zearalenone kg−1cor) were subjected to various treatments: no treatment (control), rinsed, rinsed and all floating material removed, soaked in 0.1 M sodium carbonate for 24 h or soaked in 0.1 M sodium carbonate for 24 h after removal of the floating material. All corn samples were analysed for DON and zearalenone. Rinsing the contaminated corn reduced the concentrations of both mycotoxins by 44% while soaking in 0.1 M sodium carbonate reduced the toxin concentrations an additional 35%. In both cases, removal of the floating material decreased concentrations another 8 and 4%, respectively. In the feeding study, 10‐week‐old barrows were fed diets containing 17.5% of the treated corn samples over a 21 day period. Daily feed consumption and weight gains were significantly improved in pigs fed the rinsed‐minus‐floating corn and the sodium carbonate‐soaked corn with and without floating material compared to the untreated contaminated corn. The chemical and biological data demonstrated that rinsing combined with the removal of floating material or soaking in 0.1 M sodium carbonate with or without removal of floating material were effective in reducing the toxicity of the contaminated corn. Due to a higher energy requirement needed to dry the corn soaked in sodium carbonate, the combination of rinsing and removal of the floating material is recommended as a more general and practical method of detoxification of contaminated grain.
Meat batter proteins—Effect of chemical modification on structure
Authors: Gordon A , Barbut S
Published: November 2006

The effects of five chemicals (H2O2, β‐mercaptoethanol, EDTA, urea and Tween 80) on the structure of meat protein extracts from commercial‐type poultry meat batters were studied. Disulphide bonds appeared to affect protein conformation by influencing the interactions in which hydrophobic residues were involved. The spectrophotometric data for EDTA suggested that one of the mechanisms by which it caused meat batter protein aggregation was by salt‐bridge formation through sulphydryl residues. Urea caused exposure of the hydrophobic residues in the meat batters' proteins Tween 80 did not appear to directly affect the protein‐protein interaction.
Within‐plot and within‐plant variation for seed content of soya bean protease inhibitors
Authors: Marchetti Stefano , Giordano Annalisa , Chiabå Cristina
Published: November 2006

Experiments were designed to determine the seed content of protease inhibitors in different plants of a plot or at different nodes along the main stem. The inhibitory activity of the samples was measured in vitro using sodium benzoyl‐DL‐arginine‐p‐nitroanilide as chromogenic substrate and bovine trypsin as target enzyme. Six soya bean (Glycine max Merr) strains were used, three capable of synthesizing the Kunitz trypsin inhibitor (L62‐364, Williams 82, and 594‐1) and three lacking this particular function (L81‐4590, L81‐4871, and L83‐4387). In all genotypes on trial, remarkable plant‐to‐plant variation was found, so that most strains had at least one part of the data distribution in common. Significant differences were also noted for antitryptic activities of seed samples collected at different positions on the main stem. Gradients interior to the plant varied according to the tested strain but those of Williams 82 and of its near isogenic line L81‐4590 were very similar, indicating that the amount and type of variation depended on genotype and that changes in the inhibitory activity were attributable to variation in the synthesis of inhibitors other than Kunitz.
Changes in curing agents, microbial counts and volatile compounds during processing of green bacon using two different production technologies
Authors: Andersen Henrik J , Hinrichsen Lars L
Published: November 2006

This study showed differences in salt concentration, nitrite/nitrate level and microbial load between bacon produced after modern processing concepts, represented by cured in bag (CIB) bacon, and traditional tank cured bacon (Wiltshire style). It also provided evidence for semiquantitative differences in the development of volatile compounds as analysed by headspace gas chromatog‐raphy (GC). The traditional bacon had an order of magnitude higher microbial counts, was more salty and contained more nitrite and volatile compounds after 21 days of storage. Measured differences in the content of volatile compounds in the two products could also be identified by differences in odour using the triangle difference test. Headspace GC‐MS analyses on samples of the two products stored for 21 days showed differences in 24 volatile compounds of which 19 were characteristic for the traditional tank cured product. Two of the nineteen characteristic compounds from the Wiltshire style product, 3‐methylbutanal and 1‐octen‐3‐ol, had a cheesy/malty odour and mushroom‐like odour, respectively, as analysed by headspace GC‐olfactometric analyses. This was partly consistent with comments from sensory analyses, where panellists gave the description cheesy for the odour of stored Wiltshire bacon samples. The reason for different development of volatile compounds between the two products and its possible consequence for improvement of flavour in bacon produced using modern concepts are discussed.
Characterisation of residual fibres from fermentation of pea and apple fibres by human faecal bacteria
Authors: Guillon Fabienne , Renard Catherine M G C , Hospers Jeannette , Thibault Jean‐Francois , Barry Jean‐Luc
Published: November 2006

Two dietary fibres with distinct structural features (pea hull and apple fibre) were fermented in vitro with human faecal bacteria. The composition and physicochemical properties (cation exchange, hydration properties) of the residues were examined. Gas and short‐chain fatty acid (SFCA) productions attested of the highest fermentability of apple fibre. After 24 h, 75% of the pea fibre and 42% of the apple fibre could be recovered. Production of the major SCFA, acetate, propionate and butyrate occured in the molar ratio 68:17:9 for both fibres. Uronic acid and arabinose were the most extensively fermented sugars while xylose and glucose were the least fermented. Cation exchange capacity of the two fibres did not decrease much during fermentation, which implies that the amount of bound mineral is proportional to the amount of residual fibres. The values of the hydration properties of the residual fibres were at least equal to or higher than those of initial fibres. In spite of the degradation of the fibres during fermentation, a physical structure able to retain water remained.
Disappearance of chlorophylls and carotenoids during the ripening of the olive
Authors: Mínguez‐Mosquera Isabel , Gallardo‐Guerrero Lourdes
Published: November 2006

Although the colour of olives changes from green to yellow, turning colour, purple and black according to the stage of ripeness, chlorophyll a is always the major chloroplastic pigment followed by chlorophyll b. Carotenoids are also present as minor components. Among these, lutein and β‐carotene are worthy of mention, while neoxanthin, violaxanthin and antheraxanthin are present in lower proportions. The concentration of the chlorophylls and the carotenoids decreases gradually as harvesting approaches. When the colour of the fruit is predominantly green, the percentage decrease of the carotenoid fraction is higher than that experienced by the chlorophyll fraction. In the latter fraction at this stage chlorophyll b is preferentially degraded. In contrast, in the yellow colour stage, the disappearance of chlorophylls is noticeably higher than that of carotenoids, the levels of which tend to be maintained with minimal pigment degradation at this stage. This faster degradation of the chlorophylls allows the coloration due to the carotenoids to be seen in the fruit. From this moment onwards, once the stage of ripening has begun, the rate of degradation of the chlorophyll fraction increases to almost twice that of the carotenoid fraction, and chlorophyll a disappears faster than chlorophyll b. The ratio of lutein to β‐carotene decreases as ripening advances reflecting the higher rate of degradation of lutein.
Physical properties of cold‐setting gels formed from heat‐denatured whey protein isolate
Authors: McClements D Julian , Keogh M Kieran
Published: November 2006

Cold‐setting gels were formed from a 100 g kg−1 whey protein isolate (WPI) solution (pH 7.0) which had been heated to 90°C for 30 min in the absence of salt. Heating caused the globular protein molecules to unfold and form linear aggregates, but electrostatic repulsion opposed extensive protein‐protein interactions and so prevented gel formation. When the solution containing heat‐denatured proteins was cooled to room temperature and mixed with NaCl (0.2 mol kg−1), the electrostatic charges were shielded and a gel formed. The rate of gel formation increased on cooling, which suggests that the major driving force for protein aggregation and gelation is the hydrophobic effect. Once formed, the rigidity of the gels decreased with decreasing temperature, which suggested that non‐hydrophobic forces (eg configurational entropy, hydrogen bonding, van der Waals forces and disulphide bond formation) are more important in determining the final gel rigidity. The turbidity and rigidity of gels formed by adding salt to preheated WPI at room temperature were less than those of gels formed by heating WPI in the presence of salt. The ability of WPI to form cold‐setting gels with relatively low turbidity extends the range of applications of whey proteins as functional ingredients in the food industry.
Cryoprotectants improve physical and chemical properties of frozen blue crab meat (Callinectes sapidus)
Authors: Henry L K , Boyd L C , Green D P
Published: November 2006

The storage stability of cryogenically frozen crab meat treated with cryoprotectants was compared with pasteurised and water‐treated frozen samples to determine changes in physical and chemical properties. Commercially processed, hand‐picked blue crab meat was treated with solutions of polydextrose, sucrose + sorbitol/sodium tripolyphosphate or water, vacuum packaged, and cryogenically frozen prior to storage at −29°C. All treatments were compared with an untreated reference control stored at −65°C and a pasteurised sample stored at 1.1°C. Samples were evaluated for physical and chemical changes at 4‐week intervals over 32 weeks of storage. Cryoprotectants improved oxidative stability, drip loss, expressible moisture, texture, and colour compared to untreated reference and pasteurised samples.
Chemical composition of olive by‐product and modifications through enzymatic treatments
Authors: Valiente Cruces , Arrigoni Eva , Esteban Rosa M , Amadò Renato
Published: November 2006

The purpose of the present work was to study the dietary fibre (DF) fraction of olive cake and modify the fibre structure through enzymatic treatments in order to improve the sensory quality of this by‐product for its incorporation into a baked product. Two different commercial enzyme preparations were used for enzymatic modifications: Viscozyme L, a hemecellulase/cellulase multi‐enzyme complex, and Olivex which contains different pectolitic main activities as well as various side activities, hemicellulases and cellulases. DF consists of 800 g total dietary fibre per kg dry matter. More than 91% of the DF are insoluble and the monosaccharide composition of this fraction indicates the presence of mainly cellulose and xyloglucans or xylans. Approximately 75% of the uronic acids found in olive cake are associated to the insoluble DF (IDF). Arabinans and uronic acids polysaccharides are the major fibre components in the soluble DF (SDF) fraction. Enzymatic treatments with commercial preparations caused changes in the DF content and in the IDF:SDF ratio depending on enzyme concentrations and incubation time. Baking experiments showed that a substitution of 10% of wheat flour by enzymatically modified olive cake led to an improved texture compared to products containing untreated cake.
The 15N‐isotope dilution method for determining ileal endogenous nitrogen excretion in the young (10 kg liveweight) pig
Authors: Schulze Hagen , Butts Christine A , Moughan Paul J , Verstegen Martin W A
Published: November 2006

A study was conducted with four crossbred 5‐week‐old castrated male pigs at an average body weight of 10 kg to determine the endogenous amino acid and nitrogen flows at the terminal ileum using the peptide alimentation and 15N‐isotope dilution methods. The pigs were fitted with a post‐valvular T caecal cannula and two indwelling blood catheters. They were fed a cornstarch‐based semisyn'hetic diet formulated to contain enzymically hydrolysed casein (EHC) as the sole source of nitrogen at twice their maintenance requirement for energy. Digesta were centrifuged and ultrafiltrated after collection and the precipitate plus retentate fraction (mol wt > 10000) was used to determine the endogenous amino acid and nitrogen flows. To estimate the endogenous N flow at the terminal ileum of these EHC‐fed pigs using the 15N‐isotope dilution method a constant 10 day 15N‐leucine infusion was performed at a daily rate of 5‐04 mg of 15N‐leucine (95% 15N enrichment) kg−1 body weight. The mean 15N‐enrichments above background for the trichloroacetic acid soluble blood plasma and ileal digesta nitrogen pools were 0.0249 and 0.0178, respectively. There were no statistically significant differences for 15N‐enrichment excess between the days of ileal digesta collection. The results demonstrated that glutamic acid, aspartic acid, proline and serine formed about 50% of the total ileal endogenous amino acid flow. The total daily amount of endogenous amino acid flow at the terminal ileum was 6.2 g day−1. The endogenous ileal N flows determined with the peptide alimentation and the 15N‐isotope dilution methods were similar (P = 0.40) at 1.37 and 1.17 g day−1, respectively. Endogenous N as a proportion of total N flow passing the terminal ileum was 83% and 72% for the peptide alimentation and the 15N‐isotope dilution method, respectively. The study provides some support for application of the 15N‐isotope dilution method with pigs.
Studies on the enzymatic hydrolysis of Brazilian lobster (Panulirus spp) processing wastes
Authors: Vieira Gustavo H F , Martin Antonio M , Saker‐Sampaiao Silvana , Omar Semir , Goncalves Raimunda C F
Published: November 2006

Meat recovered from the cephalothorax of the lobster (Panulirus spp), which is normally discarded during processing, was subjected to hydrolysis. The enzymes used were papain, pepsin and a fungal protease, each one tested at concentrations of 2, 4 and 5 mg g−1 (enzyme/substrate, wet weight basis). The degree of hydrolysis, measured by the release of tyrosine, was found to be highest when fungal protease was used, followed by papain and pepsin. Of the concentrations tested, it was found that 5 mg g−1 produced the highest degree of hydrolysis in the three enzymes. The protein hydrolysates produced were highly soluble, with excellent wettability and some capacity for oil emulsification. No bitter off‐flavour was detected in the final product.
Solid‐state fermentation of Lathyrus sativus seeds using Aspergillus oryzae and Rhizopus oligosporus sp T‐3 to eliminate the neurotoxin β‐ODAP without loss of nutritional value
Authors: Kuo Yu‐Haey , Bau Hwei‐Ming , Quemener Bernard , Khan Jehangir K , Lambein Fernand
Published: November 2006

The presence of a neurotoxic amino acid, 3‐N‐oxalyl‐L‐2,3‐diaminopropanoic acid (β‐ODAP), in the seeds of grass pea (Lathyrus sativus) is the cause of an irreversible spastic paraparesis, neurolathyrism, after over‐consumption. This is a negative factor in an otherwise very tasty, nutritious, easily cultivated and hardy food crop in Asia and Africa. The reduction of β‐ODAP to less than 10% of the original content has been reached by fermenting L sativas Jamalpur seeds with Aspergillus oryzae NRRL 1988 for 48 h, followed by fermentation with Rhizopus oligosporus sp T‐3 for 48 h. Other nutritional qualities were also improved in the fermented seed meal: increased content of protein, higher amino acid scores for sulphur‐containing and aromatic amino acids, better resistance to high temperature and to oxidation, and drastic reduction of the flatulence factors.
Non‐destructive determination of fat, moisture and protein in salmon fillets by use of near‐infrared diffuse spectroscopy
Authors: Isaksson Tomas , Tøgersen Geir , Iversen Arve , Hildrum Kjell Ivar
Published: November 2006

Near infrared (NIR) diffuse spectroscopy was used to determine the fat, moisture and protein contents in whole and ground farmed atlantic salmon fillets. A remote fibre‐optic probe was used for NIR measurements on 50 whole salmon fillets. The constituent ranges were: 91‐205 g kg−1 fat, 599‐709g kg−1 moisture and 186‐209 g kg−1 protein. Principal component regression resulted in the following prediction errors for ground salmon fillets, expressed as root mean square error of cross validation: 6.6 g kg‐1 fat, 3.8 g kg−1 moisture and 2.0 g kg−1 protein. The corresponding prediction errors for non‐destructive measurements on whole salmon fillets were 10.8 g kg−1 fat, 8.5 g kg−1 moisture and 3.7 g kg−1 protein. Regression models using the 760‐1100 m range gave lower prediction errors than models using the 1100‐2500 mm or 760‐2500 nm ranges. The results show that fibre‐optic probe NIR instruments are suited to determine fat and moisture in whole salmon fillets non‐destructively.
Production of raw starch digesting amylase by Aspergillus niger grown on native starch sources
Authors: Okolo Bartholomew N , Ezeogu Lewis I , Mba Charles N
Published: November 2006

Aspergillus niger isolated from rotting cassava produced raw starch degrading amylase on cassava, maize, sorghum and soluble potato‐derived starch as the sole carbon source without prior gelatinisation. Maximum activity of the amylase was attaired using cassava starch as substrate. The crude enzyme solution which comprised a mixture of raw and non raw starch digesting amylase degraded both cereal and tuber or root starches significantly. Source of assay starch significantly influenced raw starch digesting activity. Optimum pH for the raw starch degrading and the extracellular amylase were 6.0 and 3.5‐4.0, respectively. However, both enzyme activities appeared to be uninfluenced across a relatively broad pH range 3.0‐7.0. No correlation was found between the capacity of starch to induce expression of the enzyme and its susceptibility to enzyme digestion. The adsorbability of the various starches to raw starch digesting amylase was directly related to their digestibility.
Determination of lignin in the presence of ester‐bound substituted cinnamic acids by a modified acetyl bromide procedure
Authors: Morrison Ian M , Stewart Derek
Published: November 2006

The lignin content of plant materials can be determined spectro‐scopically but the presence of ester‐bound substituted cinnamic acids in the cell walls of some plant families, particularly the Gramineae, gives elevated values. Pre‐treatment with either pyrrolidine : pyridine or 0‐5 m sodium methoxide selectively removes the ester‐bound acids leaving intact the true lignin. The treatments have been applied to cellulose powder, immature perennial ryegrass stems, oat straw and forage rape stems. The pyrrolidine : pyridine treatment removes a slightly higher proportion of these non‐lignin components but the sodium methoxide treatment appears to cause less damage than the heterocyclic bases to other cell wall constituents and is preferred if the residues are to be used for other purposes.
Total lipids content and fatty acid composition of seed oils from six pomegranate cultivars
Authors: Melgarejo P , Salazar D M , Amorós A , Artés F
Published: November 2006

The fatty acid composition of the seed oils of six pomegranate (Punica granatum L) cultivars was qualitatively and quantitatively determined by gas chromatography. The seeds contained oil in the range 51‐152 mg kg−1 dry matter. Intervarietal differences in fatty acid composition were demonstrated (fatty acid esters as % (w/w) total fatty acid esters. Sour varieties had the highest while sour‐sweet varieties had the lowest oil content. Eleven fatty acids were identified. In all varieties, the predominant fatty acids were linoleic (25.2‐38.6%) and oleic acid (24.8‐35.5%) followed by palmitic (18.2‐22.6%), stearic (6.9‐10.4%) and linolenic acid (0.6‐9.9%). To a lesser extent arachidic (1.1‐3.4%) and palmitoleic acid (0.2‐2.7%) were also found in all varieties. Lauric, myristic, behenic and lignoceric acids were rarely detected. As far as we know linolenic (18:3), arachidic (20:0), behenic (22:0) or lignoceric (24:0) acids have not been previously reported in the seed oils of edible pomegranate varieties. Lignoceric acid has not previously been found in pomegranate seed oil.
Effect of γ‐irradiation on enzymatic digestion of oil palm empty fruit bunch
Authors: Matsuhashi Shinpei , Kume Tamikazu , Hashimoto Shoji , Awang Mat R
Published: November 2006

Effect of γ‐irradiation and combination treatment with alkali on oil palm empty fruit bunch (EFB) was studied to enhance the efficiency of enzymatic digestibility. γ‐Irradiation enhanced the enzymatic digestibility, and the amounts of released galacturonic acid and neutral sugars from EFB by Driselase were increased with an increase in irradiation dose. The main components of neutral sugars released from EFB were glucose and xylose. EFB treated with alkali and 50 kGy irradiation released 1200 μg g−1 of xylose that was twice amount of glucose showing that the combination treatment was effective especially to increase the digestibility of xylan.
Factors affecting in vitro formation of tannin‐protein complexes
Authors: Perez‐Maldonado Rider A , Norton Barry W , Kerven Graham L
Published: November 2006

In interaction of condensed tannins from Desmodium intortum and Lotus pedunculatus and tannic acid (hydrolysable tannin) with salivary mucoproteins (from sheep and goats), plant leaf proteins and bovine serum albumin were evaluated. These studies were carried out over a pH range of 2‐0‐9‐0 and different inorganic ion conditions to simulate conditions in which dietary proteins would interact with tannins in a ruminant digestive tract. Insoluble tannin‐protein interactions were found at pH 4–5–5–5 for bovine serum albumin and 3–5–5–5 for plant leaf protein. The present study showed that pH alone was not the sole determinant for tannin‐protein complex formation, since tannin‐protein complexation was found in the pH range 6‐0–6‐5 when different inorganic ions were added to the solutions. Insoluble complexes were not formed with salivary proteins, although precipitation by tannic acid was achieved at 5°C. This suggests that tannins may form soluble rather than insoluble complexes with salivary proteins. It was concluded that purified F1 leaf protein (the major protei occurring in leaf tissue) ought to be used as the test protein for evaluating tannin‐protein interactions for in vitro assay procedures. Using this method it was calculated that 27–43% and 19–40% of available plant protein may interact with condensed tannins from Desmodium intortum and Lotus pedunculatus, respectively.
High‐performance liquid chromatography determination of proline isomers in Italian wines
Authors: Calabrese Massimo , Stancher Bruno , Riccobon Patrizia
Published: November 2006

This paper deals with the quantitative reverse‐phase high‐performance liquid chromatography (RP‐HPLC) analysis of the isomers of proline, the most abundant amino acid in wine, and with the relative isomeric presence in samples of different vintage and geographical origin. The sample preparation was carried out by using Marfey's reagent ((‐fluoro‐2,4‐dinitrophenyl)‐5‐L‐alanine amide (FDAA)) for the derivatisation reaction in order to obtain dl and ll diastereomers of the corresponding optically active amino acids. The separation was performed with an analytical column for RP‐HPLC Nucleosil 100‐5 C18 (25 × 0.4 cm id), adopting both isocratic and gradient procedures and making use of water/acetonitrile buffers as the mobile phase. It has been observed that the best resolution is achieved under gradient conditions, although the analysis takes a long time. L‐Norleucine was used as the internal standard for quantitative determination and the detection of components was made at the fixed wavelength of 340 nm. Peak identifications were performed by comparing retention times and observing on‐line UV spectra. Under these conditions the detection limit for proline isomers reached the value of 0–5 mg liter−1. Wine samples of different ages were analysed and it is possible to see that L‐proline is present only in ‘young’ wines, while the D‐isomer appears in wines that are at least 5 years old. The most abundant D‐proline content was observed in a 30 years vintage red wine of Puglie (southern Italy) with about 15% of the ratio D to D + L.
Laser-assisted metal deposition from CuSO4-based electrolyte solution
Authors: Manshina A , Povolotskiy A , Ivanova T , Kurochkin A , Tver'yanovich Yu , Kim D , Kim M , Kwon S C
Published: November 2006

The copper spots were precipitated on the SiO2 substrates with Laser-induced Chemical Liquid phase Deposition (LCLD) method. The focused beam of the CW Ar+ laser generated in the multiwave regime was used for the metal precipitation. The deposition process was initiated by a laser-assisted photothermal chemical reaction, which results in the reduction of the metal complexes to the metal. To minimize the negative influence of the bubbles formation phenomenon the ``substrate-side'' geometry of the metal deposition has been suggested. The dependence of the metal precipitation process on the laser power and the deposition time was studied. Laser power 240 mW was found to be the threshold value for the metal deposition from the CuSO4-based electrolyte solution at the temperature 298 K.
Unilateral non‐linear dynamic contact of thin‐walled structures using a primal‐dual active set strategy
Authors: Hartmann S. , Brunssen S. , Ramm E. , Wohlmuth B.
Published: November 2006

The efficient modelling of three‐dimensional contact problems is still a challenge in non‐linear implicit structural analysis. We use a primal‐dual active set strategy (SIAM J. Optim. 2003; 13:865–888), based on dual Lagrange multipliers (SIAM J. Numer. Anal. 2000; 38:989–1012) to handle the non‐linearity of the contact conditions. This allows us to enforce the contact constraints in a weak, integral sense without any additional parameter. Due to the biorthogonality condition of the basis functions, the Lagrange multipliers can be locally eliminated. We perform a static condensation to achieve a reduced system for the displacements. The Lagrange multipliers, representing the contact pressure, can be easily recovered from the displacements in a variationally consistent way.

For the application to thin‐walled structures we adapt a three‐dimensional non‐linear shell formulation including the thickness stretch of the shell to contact problems. A reparametrization of the geometric description of the shell body gives us a surface‐oriented shell element, which allows the application of contact conditions directly to nodes lying on the contact surface. Shell typical locking phenomena are treated with the enhanced‐assumed‐strain‐method and the assumed‐natural‐strain‐method.

The discretization in time is done with the implicit Generalized‐α method (J. Appl. Mech. 1993; 60:371–375) and the Generalized Energy–Momentum Method (Comp. Methods Appl. Mech. Eng. 1999; 178:343–366) to compare the development of energies within a frictionless contact description.

In order to conserve the total energy within the discretized frictionless contact framework, we follow an approach from Laursen and Love (Int. J. Numer. Methods Eng. 2002; 53:245–274), who introduced a discrete contact velocity to update the velocity field in a post‐processing step.

Various examples show the good performance of the primal‐dual active set strategy applied to the implicit dynamic analysis of thin‐walled structures. Copyright © 2006 John Wiley & Sons, Ltd.
Reactivity of hydroxynaphthalenes towards peroxyl radicals
Authors: Pino E. , Aspée A. , López‐Alarcón C. , Lissi E.
Published: November 2006

In the present work we report data bearing on the reaction of mono‐ and dihydroxynaphthalenes towards 2,2′‐azo‐bis(2‐amidinopropane) dihydrochloride (AAPH) derived peroxyl radicals. A comparison of the bleaching rates allows establishing their relative reactivity towards peroxyl radicals: 1,2‐dihydroxynaphthalene (1,2‐DHN) ≫ 2,3‐dihydroxynaphthalene (2,3‐DHN) > 1,3‐dihydroxynaphthalene (1,3‐DHN) ≥ 2,7‐dihydroxynaphthalene (2,7‐DHN) > 1‐hydroxynaphthalene (1‐N) ≥ 2‐hydroxynaphthalene (2‐N). Bleaching rates measured under conditions of quantitative trapping of peroxyl radicals allow an estimation of the number of molecules consumed per each radical introduced into the system. The results obtained imply a chain consumption of 1,2‐DHN and 2,3‐DHN. In fact, a fast autoxidation of 1,2‐DHN is observed even in absence of AAPH. The high reactivity of this compound suggests a fast hydrogen abstraction, due to its low OH bond dissociation energy (BDE), and/or a very fast electron transfer from the deprotonated form. Oxygen radical absorbance capacity (ORAC) indexes of the naphthalene derivatives were evaluated from their effect upon the peroxyl radical promoted bleaching of c‐phycocyanin (c‐Pc). ORAC values are strongly influenced by the secondary reactions of the additive and do not correlate with the reactivity of the compound or the number of the naphthalene derivative molecules bleached per each radical. c‐Pc bleaching rate in presence of an excess of hydroxyl‐naphthalene derivative was taken as a measure of the damaging capacity of the corresponding naphthoxyl radicals. The results indicate that this damaging capacity is inversely proportional to the reactivity of the parent compound. In fact, addition of 2‐naphthol, the less reactive of the tested compounds, increases the rate of c‐Pc bleaching promoted by peroxyl radicals. Copyright © 2006 John Wiley & Sons, Ltd.