bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrolysis of galactooligosaccharides by commercial preparations of α‐galactosidase and β‐fruetofuranosidase: Potential for use as dietary additives
Authors: Slominski Bogdan A 
Published: November 2006

AbstractIn vitro and in vivo studies were conducted with six commercial enzyme preparations (SP249, Energex, Rohament CW, Novozyme 230 and crude α ‐galactosidase) to determine their effectiveness in hydrolysing galactooligosaccharides from soya bean and canola meal in the gastrointestinal tract of poultry. The use of the enzyme invertase to enhance galactoside hydrolysis was also studied. A wide range of α ‐galactosidase activity was observed in vitro, with crude α‐galactosidase from Mortirella vinacea and Novozyme 230 preparation showing the highest activity values of 4.3 and 1.5 nkat mg−1, respectively. All preparations with the exception of crude α‐galactosidase showed invertase activity which is known to convert raffinose and stachyose to the corresponding di‐and trisaccharide, melibiose and manninotriose. Although the activity of invertase was highest on sucrose, the Novozyme 230 preparation showed activity values of 4.2 and 2.3 nkat mg−1 toward raffinose and stachyose substrates, respectively. De novo synthesis of raffinose was observed when soya bean meal, canola meal or pure sucrose and galactose were incubated with certain enzyme preparations (ie Energex). In general, preparations possessing hydrolytic activity towards galactooligosaccharides showed very little synthesis of raffinose while preparations capable of generating raffinose were very weak in the hydrolysis of galactooligosaccharides. The best result in terms of galactooligosaccharide in vitro hydrolysis of canola and soya bean meal was obtained with a combination of α‐galactosidase and invertase. In the in vivo study with caecectomised hens, hydrolysis of galactooligosaccharides averaged 88% when crude α‐galactosidase (2 g kg−1) and invertase (1 g kg−1) were added to laying, hen diet containing 200 g soya bean meal per kilogram. A problem identified in the current study was that minerals such as calcium phosphate and calcium carbonate common in poultry diets inhibit the hydrolysis activity of α‐galactosidase, indicating that high levels of activity would be required to yield a response in practical poultry feeding.
Chemical reactions of benzyl isothiocyanate with egg‐white protein fractions
Authors: Kroll Juergen , Noack Jutta , Rawel Harshadrai , Kroeck Regina , Proll Juergen 
Published: November 2006

AbstractGlucosinolates and their highly reactive breakdown products (mainly isothiocyanates, ITC) belong to the group of very important natural toxicants. This paper describes the interactions of benzyl‐ITC with the egg‐white protein fractions ovalbumin, conalbumin, ovomucoid, and lysozyme and the resulting formation of protein‐ITC derivatives. Benzyl‐ITC reacts with the amino groups of the proteins, forming thiourea derivatives. Such reactions are characterised by decreases in the levels of free amino groups and available lysine. Other reaction sites of benzyl‐ITC are sulphydryi side‐chains of proteins, the results being formation of dithiocarbamate esters. This in turn results in a decrease of SH‐groups due to carbon disulphide being released from their esters. The present study describes the reactions of benzyl‐ITC with amino groups and sulphydryl side‐chains, and the subsequent decrease of lysine and crysteine after derivation. Changes in the behaviour of ITC‐derived egg‐white protein fractions were analysed by SDS‐PAGE and RP‐HPLC.
Flavonoids from the roots of two Rhynchosia species used in the preparation of a Zambian beverage
Authors: Zulu Rodah M , Grayer Renée J , Ingham John L , Harborne Jeffrey B , Eagles John 
Published: November 2006

AbstractHigh concentrations of flavonoids were found in the roots of Rhynchosia insignis and R heterophylla used for the preparation of the popular Zambian munkoyo beverage. The major flavonoids were isolated and identified by means of fast atom bombardment mass spectroscopy and co‐chromatography with authentic standards as vicenin‐2, schaftoside, isoschaftoside and an isovitexin derivative (in both species) and, additionally, vitexin, isovitexin and a violanthin‐type compound in R heterophylla. As these compounds are yellow to orange‐yellow in the concentrations found in the roots, they are likely to be responsible for the yellow coloration of the beverage before fermentation.
The glutenin fraction of wheat protein: The importance of genetic background on its quantity and quality
Authors: Pritchard P E , Brock C J 
Published: November 2006

AbstractThe influence of high‐molecular‐weight glutenin subunits on the properties of the gel‐protein fraction of glutenin proteins in wheat was determined on 20 varieties grown in the 1989 UK Recommended List trials. Both the presence of subunit 1 (chromosome 1A) and the 1B/1R rye translocation were shown to influence gel‐protein weight and breakdown rate during mixing. The gel‐protein tests were correlated with CBP (Chorleywood Bread Process) loaf volume, but they did not add anything to the correlation between Glu‐1 score and loaf volume. Both gel‐protein tests indicated that phenotypic variation could be almost as large as genotypic variation. Breakdown rate was able to detect the abnormal properties of Pastiche (weak) and Fresco (extra‐strong) that were not observed using established quality tests such as the sodium dodecylsulphate sedimentation volume.
Effect of high temperature on condensed tannin accumulation in leaf tissues of big trefoil (Lotus uliginosus Schkuhr)
Authors: Lees Garry L , Hinks Christopher F , Suttill Neil H 
Published: November 2006

AbstractPlants from three clones of big trefoil (Lotus uliginosus Schkuhr) having low, medium and high concentrations of tannin in their leaves were subjected to growing conditions with normal (20°C) and high (30°C) temperature regimes. Plants were tested every 3 weeks for foliar condensed tannin content using the vanillin‐HCl and the butanol‐HCl assays. Plants from clones growing under high temperatures matured more quickly and by 14 days had condensed tannin levels substantially greater than plants from the same clones grown under normal temperatures. Clones remained consistent with respect to their parental tannin levels throughout two trials. Leaves from high‐temperature clones suffering additional nutrient stress symptoms had very low levels of foliar condensed tannins and cross‐sections of chlorotic leaves revealed an absence of large tannin vacuoles. It is concluded that high‐temperature stress can induce the formation of additional condensed tannin in the leaves of this species.
Breakdown of amylomaize starch granules in gnotobiotic rats associated with four bacterial strains isolated from conventional rat microflora
Authors: Deiahaye Emperatriz Pacheco , Bouchet Brigitte , Andrieux Claude , Raibaud Paul , Szylit Odette , Gallant Daniel J 
Published: November 2006

AbstractBalance studies in germ‐free (GF) and conventional (CV) rats have shown that in‐vivo breakdown of amylomaize starch depends on endogenous and bacterial enzymes. In GF rats, one‐third of amylomaize starch is resistant to endogeneous digestion, whereas in CV rats starch is totally degraded, In order to study the contribution of endogenous and bacterial enzymes, the in‐vivo breakdown of amylomaize starch was compared in GF and in gnotobiotic rate associated with bacterial strains isolated from the conventional rat microflora. These bacteria were (i) a non‐amylolytic Peptostreptococcus (GNP rats),(ii) an amylolytic strain of Eubacterium able to hydrolyse resistant starch (GNE rats), and (iii) an association of Eubacterium with three other bacterial strains (Veillonella, Enterococcus and Peptostreptococcus) able to ferment the products of starch hydrolysis (GNT rats). Various studies were performed to assess the starch breakdown in the caecal contents: balance studies, light and electron microscopy and analyses of bacterial metabolites. The results show that in GNP as in GF rate, around 65% of amylomaize starch was resistant to digestion. Digestive utilization of starch was significantly improved in GNE rats (from 68 to 92%) and was further enhanced to 97% in GNT rats. The increase in starch degradation in the caecum of rats was related to a higher amylase activity and led to an increase in production of bacterial metabolites, and to a change in the proportions of short‐chain fatty acids, lactic acid and succinic acid, infrastructure study of the starch in the caecal contents showed a progressive granule hydrolysis in the order GF, GNE and GNT rats: (i) an endocorrosion of the central part of the starch granules in GF rats, (ii) a peripheral digestion with bacteria penetrating the granules in GNE rats, and (iii) a more pronounced hydrolysis in the caecum of GNT rats where the outer part of the granules were almost entirely hydro‐lysed. These results suggest that starch breakdown in the hindgut is not only due to amylolytic bacteria but also to the contribution of other glycolytic strains able to utilize the products of starch hydrolysis.
Statistical process analysis in broiler feed formulation
Authors: Alti Müsamettin , Özilgen Mustafa 
Published: November 2006

AbstractStatistical analysis of broiler feed production was done with data obtained in an industrial plant in an attempt to characterise the causes of variations in feed composition. Analysis of the experimental data has shown that the feed conversion ratio (FCR) for broilers was between 1.8 and 2.5. This large range of observations were thought to be caused by the wide range of variations in the composition of the feeds. The major factor contributing to the variance of the feed compositions was the variance of the raw materials. It was found that the proteins and moisture were distributed normally in most raw materials and feeds. Water molecules can diffuse in the raw materials and the feeds to make the whole batch uniform. On the other hand, the protein containing fractions tend to segregate due to density differences. Therefore, the moisture content of the raw materials tend to vary in a smaller range than those of the proteins. Mixing the feeds for three minutes or longer was sufficient to achieve suitable homogeneity, but controlling the range of the individual raw materials is recommended for further improvement of the process capability indices.
Effects of mincing and frozen storage on functional properties of ray muscle (Raja clavata)
Authors: Pastoriza Laura , Sampedro Gabriel , Herrera Juan J 
Published: November 2006

AbstractThis is a study on changes in protein functionality of rayfish muscle as a consequence of frozen storage in order to achieve a deeper knowledge of the effects of different degrees of cellular disruption (whole, 8 and 12 mm minced muscle) and the frozen storage temperature (−18°C and −40°C). Significant differences (P < 0.05) were found in some functional properties, with significant decreases in salt‐extractable protein and apparent viscosity, and significant increases in emulsifying capacity and water‐binding capacity after 1 year of frozen storage at 18°C. Practically no changes were observed after 2 years of frozen storage at −40°C. The greatest modifications were found in the 8 mm minced fish sample. Viscosity was the parameter that best showed the changes in whole and minced muscle stored at both temperatures. Apparent viscosity, emulsifying capacity and water‐binding capacity had a good correlation with salt‐extractable protein.
Does the method of drying a hydrated non‐starch polysaccharide affect in‐vitro analyses to predict physiological function?
Authors: Stevenson Agnes , Buchanan Callum J , Eastwood Martin A 
Published: November 2006

AbstractIt is possible to anticipate the action of dietary non‐starch polysaccharides (NSP) using in‐vitro methods. The mode of isolation of hydrated polysaccharide suspensions previous to analysis may influence the result. A commercial hydrated polysaccharide (Frucht and Faser) was isolated using four different processes and used in functional in‐vitro studies. Ethanol precipitated and heat‐dried materials had a reduced soluble NSP content. The particle size of the heat‐dried preparation differed. Heat‐drying resulted in reduced glucose immobilisation. Following fermentations there was enhanced production of total short‐chain fatty acids by heat‐dried and freeze‐dried preparations. In the description of dietary NSP the mode of isolation must be identified to allow comparison of results.
Glycoalkaloid concentration of potato tubers following continuous illumination
Authors: Percival Glynn , Dixon Geoffrey , Sword Alastair 
Published: November 2006

AbstractThe total glycoalkaloid concentration of dormant (non‐sprouted) and sprouted potato tubers cv Pentland Hawk was measured following 13 days continuous illumination (250 μmol m−2 s−2 photosynthetically active radiation) using high‐performance liquid chromatography. Comparisons were made of the influence of three sources of illumination: high‐pressure mercury, high‐pressure sodium and fluorescent tube type warm white. Glycoalkaloid concentrations in both dormant and sprouted tubers increased over 13 days illumination regardless of the form of illumination used. Glycoalkaloid concentrations accumulated with time in dormant and sprouted tubers exposed to sodium and fluorescent light but fluctuated in those exposed to mercury light. Dormant tubers were more sensitive to illumination than sprouted tubers regardless of light souce. Fluorescent light was associated with maximum glycoalkaloid synthesis in dormant tubers; while sodium light enhanced glycoalkaloid synthesis in sprouted tubers to the greatest extent. Mercury light weakly elicited glycoalkaloid synthesis in both sets of tubers. Exposure of dormant tubers to continuous light altered the ratio of α‐chaconine to α‐solanine irrespective of illumination source.
The effects of freezing, meat pH and storage temperature on the formation of white film and tyrosine crystals in dry‐cured hams
Authors: Arnau Jacint , Gou Pere , Guerrero Luis 
Published: November 2006

AbstractThe effects of freezing, meat pH and storage temperature on the formation of white film and tyrosine crystals in dry‐cured hams were evaluated in three experiments. Freezing of green hams did not affect the tyrosine concentration but increased the formation of tyrosine crystals and decreased white film intensity. The incidence of hams with tyrosine crystals and white film was lower in those with high pH meat. White film increased as the storage temperature decreased and was not found to be present around the tyrosine crystals.
In‐vitro studies on the effect of polyphenol oxidase and peroxidase on the formation of polyphenolic black tea constituents
Authors: Finger Andreas 
Published: November 2006

AbstractFlavanols (catechins and gallocatechins) isolated from green tea leaves (Camellia sinensis) (L) O Kuntze) were treated in vitro with polyphenol oxidase, peroxidase and a combination of both. The flavanol levels and those of the products formed were monitored by reversed‐phase high‐performance liquid chromatography (HPLC using spectrophotometric detection at 280 and 380 nm. Flavanols and theaflavins were quantified, whilst integrated peak areas are given for the remaining compounds. After fermentation in the presence of polyphenol oxidase higher levels of theaflavins and resolved thearubigins were obtained, whilst peroxidase produced higher amounts of chromatographically unresolved thearubigins of higher molecular weight, observed as a rise in the HPLC baseline, in the presence of peroxidase a significant decrease in the levels of all flavonol glycosides was observed, whilst in the presence of polyphenol oxidase only myricetin glycoside levels decreased.
Alkaloid, α‐galactoside and phytic acid changes in germinating lupin seeds
Authors: de la Cuadra Celia , Muzquiz Mercedes , Burbano Carmen , Ayet Gemma , Calvo Rosa , Osagie Anthony , Cuadrado Carmen 
Published: November 2006

AbstractThe aim of this work was to investigate the effect of germination on the concentrations of some antinutritional factors in Lupinus albus and L luteus seeds. The seeds were germinated for 24, 48, 72 and 96 h. The alkaloid, phytic acid and α‐galactoside changes were monitored by capillary gas chromatography and HPLC techniques. The rate of seed germination for both lupin species was lower in total darkness than when 8 h of light was supplied. The total alkaloid level was not significantly altered by 96 h germination of the seeds. Albine, α‐isolupanine, lupanine, multiflorine and 13‐OH‐lupanine were identified in L albus whereas lupinine, sparteine and lupanine were identified in L luteus. α‐galactoside levels were drastically reduced during germination of lupin seeds and stachyose was the predominant sugar in both species. The major inositol phosphate (IP6) appeared to be degraded to lower inositol phosphates during lupin seed germination. It is concluded that germination is a useful process to improve the nutritional value of lupin seeds.
The use of sodium carbonates to improve textural properties of cod minces
Authors: Kołakowski Edward , Kołakowska Anna , Lachowicz Kazimierz , Bortnowska GrażYna , Wianecki Marek 
Published: November 2006

AbstractEffects of sodium carbonates on the textural properties of fresh and frozen cod mince were evaluated. Na2CO3 and NaHCO3 (optimal does of <5 and 3 g kg−1, respectively) were found to markedly reduce weight losses after steaming (more than 25%) and to significantly improve texture and palatability despite the fact that extractability of myofibrillar protein was reduced.
Changes in protease inhibitory activity from pigeon pea (Cajanus cajan (L) millsp) during seed development and germination
Authors: Godbole Sangeeta A , Krishna Thirumalai G , Bhatia Chittaranjan R 
Published: November 2006

AbstractThe protease inhibitors from seeds of pigeon pea (Cajanus cajan (L) Millsp) have been studied for their physiological role. During seed development the inhibitor was detected even as early as 7 days after flowering (DAF). But the maximum amount accumulated between 14 and 28 DAF. During this period the seed accumulates a major portion of its proteins. During germination the inhibitor activity decreases from 6 days after germination up to 10 days. Accompanying this change there is a marked decrease in the amount of cotyledonary proteins. The inhibitor does not appear to be associated with the protein bodies. The endogenous protease from the seeds was identified as a serine protease and was not inhibited by the inhibitor. The inhibitor was earlier shown to be specific towards mammalian serine protease. Although the inhibitor did not inhibit the protease from Helicoverpa armigera larva as efficiently as soyabean trypsin inhibitor a defence role for the inhibitors cannot be ruled out.
Influence of selected process variables on the elimination of cyanide from cassava
Authors: Jones Deborah M , Trim David S , Bainbridge Zoe A , French Lisa 
Published: November 2006

AbstractThe effects of selected methods of size reduction, holding periods and drying on elimination of cyanide from cassava roots of variety MCol 1684 were investigated. Drying at 50°C eliminated approximately 50% of the total cyanide from mechanically prepared chips, and 25% from manually prepared chips. Mechanical chipping and drying at 50°C eliminated 65% of the total cyanide from small chips and 47% from large chips. Mincing of whole roots completely degraded the glucoside, and rasping and mechanical chipping degraded 70–80% and 30% of the initial glucoside respectively. The results indicate that the method of size reduction and particle size control the rate of glucoside degradation, and that the drying rate limits the quantity of glucosidic cyanide eliminated. The results are compared with those of other researchers.
Formation of volatile pyrrole products from epoxyalkenal/protein reactions
Authors: Zamora Rosario , Ríos José J , Hidalgo Francisco J 
Published: November 2006

AbstractThe production of volatile compounds in the reaction of the lipid peroxidation product (E)‐4,5‐epoxy‐(E)‐2‐heptenal with lysine or bovine serum albumin was studied in order to characterise alternative mechanisms for production of volatile pyrrole derivatives in foods. A mixture of the lipid and the ammo acid or the protein was stirred overnight at 31°C and the volatiles formed were collected using a Tenax TA trap. Several aldehydes, ketones, alkylfurans, alkyl‐ and acyl‐pyrroles, and alkylpyridines were identified by GC/MS. Formation of pyrrole derivatives in these reactions suggested the existence of alternative mechanisms for production of these flavour‐associated compounds, previously considered to be formed mainly via Maillard reactions. This new route does not need the presence of sugars, and might contribute significantly to volatile pyrrole production in foods under conditions unfavourable for classic Maillard reactions.
Flux pattern and fouling of membranes during ultrafiltration of some dairy products
Authors: Rao H G Ramachandra , Grandison A S , Lewis M J 
Published: November 2006

AbstractThe flux pattern of milk (whole milk, skimmed milk and buttermilk) showed a distinct contrast to whey (sweet whey and acid casein whey) systems during ultrafiltration (UF) at constant composition. For milk systems, the initial flux was lower than for whey systems, but the flux stabilised within a few minutes of operation. However, for both acid and sweet whey, the flux continued to fall with time for nearly 1 h. The fouling coefficient (FC) for buttermilk was 0.6 after 5 min, rising to 0.68 after 60 min. During this time flux did not decline, suggesting that concentration polarisation (CP), rather than fouling, was controlling the flux rate. In contrast, the FC for whey was 0.5 after 5 min with a progressive rise over the next 55 min, but the flux also fell throughout this period suggesting that flux was controlled by fouling rather than CP. The higher concentration of protein in milk systems appeared to be responsible for CP, rather than fouling, being the controlling mechanism.
Forage plant cyclitols are readily fermented by the ruminant
Authors: Lowry J Brian , Kennedy Peter M 
Published: November 2006

AbstractIn an in vitro rumen fermentation system the plant cyclitols, inositol, pinitol and quebrachitol were degraded within 48 h with gas evolution, an index of fermentation, comparable to that from mannitol and cellulose. Most of the cyclitol ring carbons appeared as volatile fatty acids (acetate, 1.2–1.5 mol; propionate, 0.8–1.0 mol). Their value as an energy source for the ruminant can thus be equated with soluble sugars, in marked contrast to their role in monogastric animal nutrition. They may be important in dry‐season tropical pastures because of their high levels in water‐stressed legumes.