bluuebunny/crossref_metadata_2025 huggingface dataset:
Carotenoids in cassava: Comparison of open‐column and HPLC methods of analysis
Authors: Adewusi Steve R A , Bradbury J Howard
Published: November 2006

Cassava leaves and tubers from six cultivars were analysed for carotenoids by both open‐column chromatography and high‐performance liquid chromatography (HPLC). The major carotenoids of leaves were the non‐vitamin A carotenoid lutein (86‐290 mg kg−1 fresh weight (FW)) and the pro‐vitamin A carotenoid β‐carotene (13‐78 mg kg−1 FW). Immature leaves contained less than mature leaves. Tubers contained 0.1‐3 mg kg−1 FW of β‐carotene and 0.05‐0.6 mg kg−1 FW of lutein. Carotenoids present in small amounts included α‐, γ‐, and §‐carotenes and β‐cryptoxanthin and others were separated and partially identified. Yellow tubers contain much more β‐carotene than white tubers and cassava is a good source of pro‐vitamin A carotenoids compared with other root crops. Both methods gave similar results for β‐carotene and lutein, but the open‐column method did not allow separation and quantitation of carotenoids present in small amounts. HPLC separated many carotenoids, but most peaks could not be identified for lack of reference compounds. A great advantage of open‐column chromatography for developing countries is its use of simple equipment and readily available reagents and solvents compared with HPLC, which requires complex equipment needing careful maintenance and expensive solvents. The open‐column method is more labour intensive but this is not a constraint in developing countries.
Prediction of apparent heal protein digestibility in pigs with a two‐step in‐vitro method
Authors: Cone John W , Van Der Poel A (Thomas) F B
Published: November 2006

The use of a two‐step in‐vitro method to predict the in‐vivo ileal digestibility of proteins in pigs was investigated. It proved not possible to predict accurately the ileal protein digestibility with the in‐vitro method. By dividing the samples into groups of closely related products, a good relationship (r2 = 0.93) between in‐vivo and in‐vitro data was only obtained for wheat products, where only five samples were analysed. For beans, peas, rapeseed products and soya bean products it was still not possible to predict the in‐vivo protein digestibility (r2 = 0.03‐0.60). The in vivo‐in vitro relationship was mainly determined by the properties of the proteins and the presence of antinutritional factors, such as lectins and trypsin inhibitors. The first influences both the in‐vitro and in‐vivo protein degradability and the latter only reduces the in‐vivo degradability by stimulating the secretion of endogenous protein. It is suggested that, with the in‐vitro method, real ileal digestibility of proteins is predicted. The apparent ileal protein digestibility can only be predicted with the in‐vitro method after making corrections for the influence of these antinutritional factors on the secretion of endogenous protein. Possibly corrections are also needed for microbial protein, and protein which is solubilised in the small intestine but not absorbed because of the physical state of the chyme.
Determination of RNA and ATP in the rumen liquid of cows fed with diets differing in forage to concentrate ratio
Authors: Susmel Piero , Plazzotta Emanuela , Mills Colin R. , Stefanon Bruno
Published: November 2006

The effect of dietary composition on the RNA and ATP concentrations in rumen bacteria was determined. Four dry Simmental cows received two diets (H, hay only; C, hay and concentrate) and samples of rumen fluid were taken at three different times during the day. Rumen fluid was analysed for DM, N, pH, VFA, RNA, ATP and total bacterial count. There were no significant differences in RNA concentration whether it was determined in fresh or frozen samples or after having been precipitated overnight. The effect of time of sampling was almost always significant: for pH, ammonia nitrogen, propionic acid, n‐butyric acid and total VFA this was particularly evident at 12:00 h in comparison with 08:00 and 16:00 h (P < 0·05). Bacterial DM, total count and ATP content decreased linearly with increasing time from the morning meal (P < 0·01), while the highest RNA content was observed at 12:00 h and the lowest at 16:00 h (P < 0·01). The bacterial content (DM basis) of RNA and the RNA:N, RNA:total count and ATP:N ratios were significantly higher with diet C, while differences for ATP (μg mg−1 DM), nitrogen (mg per 100 mg DM) and ATP:RNA ratio were not significant. The effect of sampling time was similar for the two diets: the RNA content of bacterial cells increased from 08:00 h to 12:00 h (P < 0·05), while the RNA:N, RNA:total count and ATP:RNA ratios increased from 08:00 to 12:00 h and decreased from 12:00 to 16:00 h. The ATP content had a similar trend to that of RNA, but differences with time were not significant. Although the use of RNA and ATP as bacterial markers has to be considered with some caution, their determination together with rumen parameters, such as pH, VFA and ammonia, could contribute to useful investigations of the anaerobic fermentative process.
Genotype—environment interactions for protein content in chickpea
Authors: Singh K. B. , Bejiga G. , Malhotra R. S.
Published: November 2006

Winter sowing of chickpea (Cicer arietinum L) has been intoduced in the Mediterranean region with the prospect of increasing seed yield by 50–100% over spring sowing. Since the influence of season on protein content is not known, this study was conducted to determine it. Another objective was to determine the genotype–environment interactions for protein content. Five sets of trials, comprising 20–24 entries each, were conducted at three locations and during two seasons. The estimates of variance components involving first‐order interactions [genotype (G) × location (L), genotype × season (S)] were small, indicating that the contribution of L and S in the genotypic expression of protein content was generally small. The mean squares due to the genotype × environment (linear) portion of interaction were non‐significant, showing that there were no differences in the linear expression of G. Furthermore, the present study demonstrated that the overall difference in protein content in the seeds of two seasons was only 0·11%, indicating that the protein content in seed was little affected by sowing date.
Chemical composition of Colletia spinosissima seeds
Authors: Zygadlo Julio A. , Guzmán Carlos A.
Published: November 2006

Colletia spinosissima is a small shrub of the Argentina forest. The oil and protein contents of the seeds are 500 g kg−1 and 250 g kg−1, respectively. The major fatty acids in the oil extracted from the seeds are oleic (448 g kg−1), linoleic (232 g kg−1) and linolenic (151 g kg−1). Sitosterol is the main component of the sterol fraction.
Identification by epr spectroscopy of carvacrol and thymol as the major sources of free radicals in the oxidation of plant essential oils
Authors: Deighton Nigel , Glidewell Sheila M. , Deans Stanley G. , Goodman Bernard A.
Published: November 2006

The formation of stable free radicals upon reaction of the essential oils of 10 plant species with ultraviolet radiation and the superoxide radical anion, O2−, has been investigated by electron paramagnetic resonance (EPR) spectroscopy. Only the oils from oregano, summer savory and thyme produced EPR spectra and the results can be accounted for in terms of free radicals produced by the closely related phenolics, carvacrol and thymol. These observations are interpreted in terms of the known antioxidant properties of these molecules.
Impact of temperature and cellulase treatments on rheological behavior of potato tuber cell suspensions
Authors: Shomer Ilan , Rao M. A. , Bourne Malcolm C. , Levy David
Published: November 2006

The rheological behavior of suspensions of potato tuber cells after gelatinization of starch and enzymatic degradation of cellulose was studied. Elevating temperatures from 20 to 70·C resulted in a respective increase in storage modulus (G′) and decrease in loss modulus (G″) and complex dynamic viscosity (η*). The gelatinized starch behaves as an inflationary agent affecting cell elasticity and friction. Degradation of the cell wall by cellulase reduced G′, G″, and η* at all oscillation frequencies. Enzymatic degradation of the cell wall exhibited apparent second‐order behavior in relation to G′ and η*. Enzymatic removal of the cell wall resulted in the breakdown of the cell structure, dispersion of the intracellular starch, and liquefaction.
In vitro hydrolysis of phytate at 95°C and the influence of metal ion on the rate
Authors: Bullock Joseph I. , Duffin Paul A. , Nolan Kevin B.
Published: November 2006

The in vitro hydrolysis of phytate at 95·C across the pH range 1–12 is reported. The reaction is slow. The first order rate constant varied from 3·98 × 10−4 min−1 at pH 1 to 0·28 × 10−4 min−1 at pH 12 with a maximal value of 8·74 × 10−4 min−1 at pH 4. The reaction is very similar in rate and profile to that of a phosphoric acid ester anion, [(RO)PO3H]−1. The 12 metal ions tested had little influence on the hydrolysis reaction although the phytate: metal ion ratio was necessarily high because of the insolubility of phytate metal salts at lower ratios.
Physicochemical properties and cooking quality of four new cultivars of Nigerian cowpea (Vigna unguiculata L walp)
Authors: Giami Sunday Y. , Okwechime Uzodima I.
Published: November 2006

Four new cowpea cultivars (IT81D‐699, IT82E‐18, IT84S‐2246‐4 and TVx 3236) were evaluated for their physicochemical properties and cooking quality. The four cultivars fell into two categories (rough and smooth) according to testa texture, and varied in seed dimensions and weights with IT81D‐699 and IT84S‐2246‐4 having smaller seed volume than IT82E‐18 and TVx 3236. Leached solids, swelling capacity and seed coat percentage were within a range of 0·33–0·94 g per 100g, 77·0–123·5 g per 100 g and 5·6–15·7% w/w of dry beans respectively. The total polyphenol content of the brown or cream‐coloured beans were similar (1·53–1·96 mg g−1) but higher than the amount (1·03 mg g−1) found in the white bean. Cooking time varied between 29 and 37 min and was reduced by about 21% following a presoaking treatment in water for 12 h at room temperature (28 °C). Cooking time was significantly positively correlated (P < 0·05) with seed weight (r = 0·82) and seed volume (r = 0·75). Water absorption was not related to cooking time, and was much lower for the cultivar with larger seeds. No significant difference in hardness was found between unsoaked beans cooked for 30 min and soaked beans cooked for 10 min, suggesting that cookability for all cultivars was improved through soaking.
Studies on the quantification of specific cyanogens in cassava products and introduction of a new chromogen
Authors: Essers Sander A. J. A. , Bosveld Margaret , Van Grift Remco M. Der , Voragen Alfons G. J.
Published: November 2006

The enzymic assay for cyanogens in cassava as developed by Cooke (1978) and improved by O'Brien et al (1991), was compared with a standard method, involving autolysis/steam distillation/titration, and further improved with a more acceptable coloration and other minor changes. Cooke's assay, using a linamarin calibration curve, gave similar values for cyanogenic potential in fresh cassava as the standard method. For cassava samples with high non‐glycosidic cyanogen levels, Cooke's assay yielded slightly lower values. Isonicotinate/1,3‐dimethyl barbiturate as reagent in the König reaction had the following advantages compared with the so far applied pyridine/pyrazolone color reagent. It is less toxic and does not release repulsive vapours. It is faster, cheaper and easier to handle, and has increased sensitivity and longer storability. Direct measurement of cyanogenic potential was accurate in extracts containing 35–700 μM. Recovery of linamarin supplements was 102±4%. Separate calibration curves of linamarin, acetone cyanohydrin and KCN were necessary for accurate calculation of cyanogenic glycosides and cyanohydrin levels. Extract storability depended slightly on storage temperature, but was not changed by inclusion of ethanol in the extract medium.
Rapid assessment of the adulteration of virgin olive oils by other seed oils using pyrolysis mass spectrometry and artificial neural networks
Authors: Goodacre Royston , Kell Douglas B. , Bianchi Giorgio
Published: November 2006

Curie‐point pyrolysis mass spectra were obtained from a variety of extra‐virgin olive oils, prepared from various cultivars using several mechanical treatments. Some of the oils were adulterated (according to a double‐blind protocol) with different amounts of seed oils (50–500 ml of soya, sunflower, peanut, corn or rectified olive oils per litre of mixed oil). Canonical variates analysis indicated that the major source of variation between the pyrolysis mass spectra was due to differences between the cultivars. rather than whether the oils had been adulterated. However, artificial neural networks could be trained (using the back‐propagation algorithm) successfully to distinguish virgin oils from those which had been adulterated.
In‐vitro multienzyme digestibility of protein of some plant source flours blended with bovine plasma protein concentrate
Authors: Oshodi A. A. , Hall G. M.
Published: November 2006

The in‐vitro multienzyme protein digestibilities of the flours of maize, cassava, pigeon pea (Cajanus cajan), African yambean (Sphenostylis stenocarpa) and bambara groundnut (Vigna subterranea), blended with bovine plasma protein concentrate were investigated. The multienzyme system consists of trypsin, chymotrypsin and peptidase. It was found that the addition of bovine plasma protein concentrate improved the protein digestibility of the flours compared with flours without the additive. The digestibilities were increased by between 3% in bambara groundnut blended flour to about 10% in cassava blended flour. When the flours were wet‐heat treated, the digestibilities further increased in all samples with increments between 7·5 % in bambara groundnut and 16·6% in cassava flour. Bovine plasma protein concentrate may be a good source of protein for the fortification of protein‐deficient foods, particularly maize and cassava flours.
Research on white and red wine blending in the production of rosé wines by means of the partial least squares method
Authors: García‐Jares Carmen , Médina Bernard
Published: November 2006

The difficult problem of recognizing wine blends in rosé wines is assessed using a powerful statistical method called partial least squares. Genuine rosé wines are first detected using a 280 nm/320 nm spectrophometric ratio. Blends of white and red wine are used as a calibration set and for an evaluation set of known composition. The proposed method evaluates the respective percentage of red and white wine in a blend and the error associated with the prediction. A comparison is made with principal component regression.
Potential of in‐field and low temperature drying for reducing chlorophyll contents in canola (Brassica napus L)
Authors: Cenkowski Stefan , Jayas Digvir S. , Daun James K.
Published: November 2006

The presence of green seeds in canola arises primarily from the common practice of swathing the crop prematurely in order to hasten the harvesting process and reduce the shattering losses. The purpose of this study was to determine the effects of plant maturity, swathing and duration of swathing on moisture and chlorophyll contents of canola seeds (Brassica napus L cv Westar), and to determine the effect of canola conditioning with air at 25·C and 90% RH on chlorophyll content. A standing crop of canola with 50% to 10% (w/w) seed moisture content was sampled at regular intervals in two consecutive harvest years (1989 and 1990). Canola was also swathed at three different stages of maturity, and seeds were checked for chlorophyll at 2‐3 day intervals and compared with chlorophyll contents of seed from standing crop. Samples were conditioned in a thin layer with air at 25·C and 90% RH for 24 h, and chlorophyll was determined before and after conditioning. The chlorophyll of seeds decreased exponentially with a decrease in moisture content. Conditioning canola seeds decreased chlorophyll content by an average of 16% (SD = ± 12%).
Detoxification of cassava during fermentation with a mixed culture inoculum
Authors: Padmaja G. , George Mathew , Moorthy S. N.
Published: November 2006

The efficacy of a mixed culture inoculum in detoxifying intact cassava tuber and peel pieces was investigated. Fermented cassava tuber and peel pieces had more linamarase activity than the non‐fermented control samples and this might have resulted partly from the release of endogenous linamarase from the retted tuber/peel pieces and partly due to the microbial linamarase. Approximately 24–26% of the total cyanide remained in the bound form in the fermented tuber while 67–79% existed as bound cyanide in the non‐fermented controls. In cassava peels, only 15–33% of total cyanide remained in bound form after 72 h fermentation while 58–59% cyanide existed in bound form in the parallel non‐fermented control peels. Free cyanide which could be easily eliminated through sun‐drying was present at higher concentrations in the fermented tuber and peel compared with the non‐fermented samples. The study showed that cassava tuber and peel could be extensively detoxified through fermentation with a mixed culture inoculum.
Effects of γ‐irradiation on the flavour of dry shiitake (lentinus edodes sing)
Authors: Lai Chung‐Long , Yang Jui‐Sen , Liu Ming‐Sai
Published: November 2006

Dry shiitake (Lentinus edodes Sing) was irradiated with doses of 5 and 10 kGy using 60Co. The total volatile compounds were decreased by more than 50%. Irradiation increased the concentrations of some minor volatile compounds, such as 3‐methyl‐2‐butanol and I‐hexanol. However, the major flavour compounds including eight‐carbon and sulphur‐containing compounds were significantly reduced. The ratio of the eight‐carbon compounds, such as 3‐octanone, 3‐octanol and 1‐octen‐3‐ol, to total volatiles decreased from 72% in the control to 21% in the 10 kGy irradiated samples. The unidentified compounds which may have been formed by decomposition or polymerization following irradiation of precursors need to be studied in greater depth.
The use of reverse‐phase C18‐bonded silica for the trapping, concentration and analysis of headspace vapour from model organic compounds, banana pseudostem and black pepper
Authors: Ndiege Isaiah O , Otieno Dalmas O , Budenberg William J , Hassanali Ahmed
Published: November 2006

A study of recovery efficiency of a series of volatile compounds trapped on reverse‐phase C18‐bonded silica has shown that reverse‐phase silica is a useful addition to the existing range of adsorbents available for headspace volatile concentration and analysis. A gas chromatograph comparison of the airborne volatiles from black pepper (Piper nigrum) and banana pseudostem (Musa sp) recovered from reverse‐phase silica, activated charcoal and Porapak Q traps shows no qualitative differences in the components present.
Influence of the storage conditions on some physicochemical and mycological parameters of honey
Authors: Jiménez Misericordia , Mateo José Juan , Huerta Tomás , Mateo Rufino
Published: November 2006

The authors studied the changes in yeast and mould counts, pH, free and lactone acidity, colour and sugar composition undergone by honeys with water contents of 169, 188 and 220 g kg‐1 on storage at refrigeration temperature (4–7°C), room temperature and 28°C for two years. Of the solid culture media assayed, honey agar and osmophilic medium fostered yeast growth while malt‐extract agar and yeast‐extract‐malt‐extract agar allowed for better development of filamentous fungi. The yeasts isolated belonged to the genera Saccharomyces, Schizosaccharomyces and Zygosaccharomyces, while filamentous moulds were of the genera Aspergillus, Penicillium, Fusarium and Alternaria. The honeys studied underwent no visible microbial alternations under any of the conditions tested, although yeast population increased significantly with time. Free and lactone acidity increased slightly but the pH was practically constant. The honeys darkened gradually with time, the effect increasing with the storage temperature. The analysis of various sugars carried out by capillary column gas chromatography of their trimethylsilyloxime derivatives indicated that all of them changed significantly after 2 years. Levels of fructose, glucose, sucrose, maltose, kojibiose, isomaltose and trisaccharides decreased with time whereas those of maltulose and turanose increased over the same period.
Occurrence and distribution of ppo activity in floral organs of some standard and local cultivars of tea
Authors: Singh Harsh P , Ravindranath S D
Published: November 2006

Variation of the polyphenol oxidase (PPO) activity in tea flower organs was studied among established cultivars and plants grown locally. Intervarietal differences among the soluble and bound components of the enzyme in floral organs were observed. Quantitative traits were found to be highly conserved among plants of the same clones but differed widely among plants of different clones and of local varieties/cultivars. The latter originated from seeds and some heterogenity was to be expected.
Feeding Jerusalem artichoke (Helianthus tuberosus) to pigs
Authors: Farnworth Edward R
Published: November 2006

Weaned pigs were fed diets with added Jerusalem artichoke for 28 days. In a first trial, the pigs received raw tubers in addition to their normal ration. In a second trial, the pigs received dried Jerusalem artichoke (10–60 g kg‐1) in the diet. Pigs eating the raw tuber had significantly increased body weight gains due to the consumption of the raw tuber, but significantly decreased feed efficiency. Adding dried Jerusalem artichoke to the diet significantly increased weight gains. Feed efficiency was improved, but not significantly. Faecal valeric acid concentration was significantly increased in animals eating Jerusalem artichoke.
Amino acid and energy digestibility in peas (pisum sativum) from white‐flowered spring cultivars for growing pigs
Authors: Fan Ming Z , Sauer Willem C , Jaikaran Sam
Published: November 2006

Six barrows, average initial weight 35 kg, fitted with a simple T‐cannula at the distal ileum, were used to determine the apparent ileal digestibilities of amino acids (AA) and the digestibility of energy in six diets according to a 6 x 6 Latin square design. The pigs were fed six corn starch‐based diets formulated to contain 165 g CP per kg from six different white‐flowered spring pea cultivars. Chromic oxide was used as the digestibility marker. The pigs were fed twice daily, at 08:00 and 20:00 h. Each experimental period lasted 9 days. Faeces were collected from 08:00 on day 6 to 08:00 h on day 8; ileal digesta from 08:00 on day 7 to 08:00 h on day 9. Of the indispensable (+semi‐) AA, there were differences (P≤0.05) in the AA digestibilities of arginine, methionine, phenylalanine and tyrosine between the cultivars. In the same order for these AA, the digestibilities ranged from 81.3 to 89.0%, 67.8 to 75.1%, 68.0 to 74.6% and 66.1 to 74.8%, respectively. Within each cultivar, the digestibilities of cysteine and threonine were relatively low, ranging from 58.5 to 65.9% and from 59.6 to 67.4%, respectively. The digestibility of lysine was relatively high, ranging from 80.3 to 84.0%. The energy digestibilities in the pea cultivars ranged from 87.4 to 90.2% (P≤0.05); the digestible energy content from 14.0 to 14.4 MJ kg‐1 DM. There was considerable disappearance of energy in the large intestine, ranging from 4.4 to 6.2 MJ kg‐1 DM intake from peas. In conclusion, when measured with the ileal analysis method, there were differences (P≤0.05) in the digestibilities of some of the indispensable AA between the pea samples. Furthermore, the relatively low digestibilities of methionine and cysteine further accentuate the limitation of the sulphur‐containing AA in protein from peas.
Physical characteristics of siliqua and lipid composition of seeds located at different positions in mature mustard inflorescence
Authors: Munshi Satish K , Kumari Anita
Published: November 2006

The siliquas in positions 5–27 on the mustard (Brassica juncea L.) inflorescence were healthier and larger having a significantly higher dry weight per siliqua, dry matter and oil content per seed than those in positions 1–3 and 29–49, at maturity. However, the dry matter content decreased by 43% from positions 1 to 49. The seeds in positions 27 and above on mustard inflorescence have a different lipid composition because these are less developed and, thus, contain less storage lipids in comparison with those towards the basal end. Correspondingly, there was an increase in the content of phospholipids, glycolipids, free fatty acids and oleic acid in the seeds from siliqua position 27 and above as compared with those from other regions of mustard inflorescence. The content of erucic acid was comparatively less in the seeds in the upper region.
Effect of freezing upon alliinase activity in onion extracts and pure enzyme preparations
Authors: Urs Wäfler , Shaw Martin L , Lancaster Jane E
Published: November 2006

Alliinase is the enzyme ultimately responsible for the development of the flavour compounds in onions and other alliums. Freezing of onions has been shown to result in a lack of flavour and pungency due to the destruction of alliinase activity. It was therefore thought that the enzyme is susceptible to freezing. However, the results of this paper show that purified alliinase can be stored at –80°C without any loss of activity. The enzyme also remains active after quick freezing of fresh tissue in liquid nitrogen. Inactivation of the enzyme occurs only after slow freezing or thawing procedures. Resu'ts show that cell proteases are not likely to be involved.
Changes in the quality parameters of clonal black tea due to fermentation time
Authors: Owuor Philip O , Orchard John E , McDowell Ian J
Published: November 2006

Flavour index and Group II volatile flavour compounds of clonal black tea progressively decreased while Group I compounds increased during fermentation process. However, theaflavins in made black tea and tasters' evaluation of such tea changed in a quadratic manner with fermentation time. The rate of production of the individual theaflavins varied within a clone and between different clones as fermentation progressed. The results explain the errors obtained when only one quality parameter is used to estimate optimum fermentation time in black tea manufacture.
Further characterisation of protease inhibitors from pigeon pea (cajanus cajan (l) millsp) seeds
Authors: Godbole Sangeeta A , Krishna Thirumalai G , Bhatia Chittaranjan R
Published: November 2006

Cajanus trypsin inhibitor (CTI) and Cajanus trypsin‐chymotrypsin inhibitor (CTCI) previously purified from cv TAT‐10 were further characterised. The modification of the inhibitors revealed the presence of lysine at the trypsin reactive site in both CTI and CTCI. Modification of tyrosine at the reactive site of CTCI did not abolish chymotrypsin inhibition suggesting the presence of leucine or phenylalanine as reported in other chymotrypsin inhibitors. CTCI did not contain tryptophan. Dissociation constants for the inhibitors with bovine trypsin were in the region of 0.69 nmol (CTCI) and 0.029 nmol (CTI). Although the protease inhibitors lost their inhibitory activity on exposure to 2‐mercaptoethanol they remained attached to the enzyme. The inhibitors were not very effective against the protease from Helicoverpa armigera which is a serious field pest of Cajanus. Dissociation constants for the inhibitors with the larval enzyme were in the region of 100 nmol.
Effect of hydrogen peroxide‐dependent enzyme systems on the in‐vitro digestibility of untreated and ammonia‐treated barley straws
Authors: Chaudhry Abdul‐Shakoor , Miller Eric L
Published: November 2006

A series of small‐scale in vitro experiments was conducted to evaluate the effectiveness of various hydrogen peroxide (H2O2)‐dependent enzyme systems, peroxidase and glucose oxidase, in improving the nutritive value of ammonia‐treated and untreated barley straw. H2O2 and peroxidase increased (P≤0.001) digestibilities when used individually, but their combined use did not influence digestibility significantly (P>0.05). The effect of H2O2 alone was greater than that of peroxidase alone. The combination of glucose and glucose oxidase to generate H2O2 produced a small but non‐significant (P>0.05) increase in the digestibility of straw. The combination of glucose oxidase and peroxidase was ineffective in improving digestibility of straw. The digestibility values of ammonia‐treated barley straw were always greater (P≤0.001) than those of untreated straw but none of the treatments showed any interaction with ammonia treatment. It is suggested that H2O2 treatment improves the digestibility of straw.
Variation in fatty acid composition of palm oils from two varieties of the oil palm (Eelaeis guineensis)
Authors: Ekpa O D , Fubara E P , Morah F N I
Published: November 2006

A comparative study was carried out on the fatty acid content of palm oil samples from the red and yellow fruits of Dura and Tenera varieties of Elaeis guineensis in the dry (January) and wet (May) seasons. Significant differences in the fatty acid content of the oils from the two varieties were observed. The degree of total unsaturation of the oil samples varied, with oil from red fruits of Dura having the highest total unsaturated fatty acids.
Relationships between processing conditions and starch and protein modifications during extrusion‐cooking of pea flour
Authors: Valle Guy Della , Quillien L , Gueguen J
Published: November 2006

Pea flour was extruded under various conditions; extrusion treatment was characterised by specific mechanical energy (SME), moisture content, shear rate at the die and product temperature. Product transformation was measured by starch solubility, protein solubility in specific buffers and by immunoassay with anti‐legumin antibodies. Response surfaces showed that SME influenced starch and protein solubility more than did temperature. Decrease of protein solubility was attributed to formation of non‐covalent bonds and disulphide bonds which could partly take place at the die, according to flow conditions. The most severe extrusion conditions (SME>250 kWh t−1) led to the creation of other covalent bonds. Immunoassay proved an efficient method for assessing the severity of treatment by following the loss of legumin antigenicity.
Effect of various agents on rheological properties of carrot cells and protoplasts
Authors: Ramana Sundara V , Taylor Andrew J
Published: November 2006

It is known that cell turgor pressure affects the rigidity of plant cells and plays a major role in determining the texture of some plant tissues. The role of cell components in maintaining this turgor pressure (and therefore rigidity) during processing was studied by using agents that affect principal components of cell walls and cell membranes. Cells were prepared from carrot tissue by an enzymic method which removed the middle lamella; further treatment yielded protoplasts. Measurement of the rigidity of carrot cells and protoplasts (related to the complex dynamic modulus G*) showed that cells were more rigid and lost rigidity more slowly on heating than protoplasts. The effect of osmotic pressure on cell rigidity was examined by treating cells with mannitol solutions (0.1–1.0 M) and measuring G* at 20°C and during heating from 20 to 90°C. Cells treated with 0.1 and 0.2 M mannitol had higher initial values of G* compared with the control sample and G* increased with temperature. Cells treated with mannitol solutions above 0.4 M showed lower G* values than the control and little change in G* during heating. Carrot cells and protoplasts were treated with enzymes and the effect of the treatments on rigidity measured. Pronase (a protease) treatment of cells gave a higher initial G* value than the controls and G* also increased with temperature but lipase (EC3.1.1.34) had no effect on cells. Both Pronase and lipase had a marked effect on the rigidity of protoplasts causing a reduction in the initial G* value which decreased further on heating. Cells treated with detergents (dodecyl sulphate and Triton X‐100) showed higher initial G* values compared with controls and G* increased with temperature. Microscopic studies indicated that degergents caused flocculation of the cells. With protoplasts, dodecyl sulphate caused a complete loss of rigidity and Triton X‐100 also reduced the rigidity significantly. There were no signs of flocculation with protoplasts.
Effect of amylose/amylopectin content, milling methods, particle size, sugar, salt and oil on the puffed product characteristics of a traditional thai rice‐based snack food (Khao Kriap Waue)
Authors: Jomduang Somchai , Mohamed Suhaila
Published: November 2006

Factors affecting the quality of Khao Kriap Waue (KKW)‐a traditional Thai glutinous‐rice‐based puffed‐snack were studied. The moisture content and expansion ratio of KKW were positively correlated to amylopectin and negatively correlated to the amylose content of the flour, while hardness and bulk density were negatively correlated to amylopectin and positively correlated to amylose. Wet‐milled flour produced good‐quality puffed KKW, unlike dry milled flour. The smaller the flour particle size the better the product quality The addition of sugar and salt helped improve puffed product quality. The optimum amounts of added sugar and salt were 200–300 g and 0–20 g per kg of flour, respectively. Adding oil did not improve the processing and puffed product quality of KKW.
Comparative study of the aromatic profiles of two different plum species: Prunus salicina Lindl and Prunus simonii L
Authors: Gómez Encarna , Ledbetter Craig A
Published: November 2006

Volatile compounds of two plum species (Prunus salicina Lindl and Prunus simonii L) were analyzed by capillary gas chromatography‐mass spectrometry using simultaneous vacuum distillation extraction. Aroma patterns were identified and quantified. A total of 60 compounds were identified, of which 23 were unique to P simonii. The profile of P simonii, as well as a study of the odor unit values of some identified compounds, indicated a much stronger aroma than P salicina. Hexyl acetate, which produces a characteristic apple aroma, was present in P simonii at levels 50‐fold higher than in the studied cultivars of P salicina.
Activity of two lignin biosynthesis enzymes during development of a maize internode
Authors: Morrison Teresa A , Kessler J Raymond , Hatfield Ronald D , Buxton Dwayne R
Published: November 2006

To ascertain the temporal relationships of phcnylpropanoid and lignin pathway enzymes, phenylalanine ammonia‐lyase (PAL) and cinnamyl alcohol‐ NADPH dehydrogenase(CAD), with lignin concentration, PAL and CAD activities and lignin concentrations were assessed during progressive development of the 10th internode in maize (Zea mays L). Enzyme activities were quantified and lignin concentrations were determined by the detergent system of fiber fractiona‐ tion from lower, middle, and upper sections of the elongating internode harvested 3, 5, 7, 9, 11, 13, and 15 days after the internode had reached 10 mm in length. Over 15 days, a coordinated, sequential, and basipetal pattern of enzyme activities and lignin accumulation evolved through the internode, spanning the stages of rapid elongation, cellular differentiation, and secondary cell wall formation. PAL activity was initiated first, rising to peak activity in elongating tissue, and falling basipetally in tissues as they matured. CAD activity rose in fully elongated, maturing internode tissue where PAL activity was waning following its peak activity. Lignin accumulated in tissues with high CAD activity. CAD activity and lignin deposition patterns were similar: simultaneously increasing in activity and deposition over time while activity and deposition also shifting basipetally through the internode, keeping pace with secondary cell wall formation. Lignin concentration correlated significantly with CAD, but not with PAL.
Purification and characterisation of basic ascorbate oxidase from satsuma mandarin (Citrus unshiu Marc)
Authors: Saari Nazamid Bin , Fujita Shuji , Haraguchi Kazuyuki , Tono Tetsuzo
Published: November 2006

Basic ascorbate oxidase of the multiple enzyme forms existing in young fruit of satsuma mandarin (Citrus unshiu Marc) has been separated and subsequently purified to electrophoretic homogeneity through (NH4)2SO4 fractionation and chromatographies on DEAE‐Toyopearl 650M, CM‐Sephadex C‐50 and Sephadex G‐100. The native molecular weight was estimated to be 141 kDa by gel filtration and composed of two non‐identical subunits with an apparent mass of 74 kDa and 62 kDa. The optimum pH was found to be 5.5 with reasonable stability between pH 5 and 8. The enzyme had an optimum temperature at 45°C and was stable up to 50°C upon heat treatment for 5 min. The presence of sodium diethyldithiocarbamate, metabisulphite and potassium cyanide completely inhibited the enzyme activity. Fluoride also inhibited the activity substantially at higher concentrations. Other tnonovalent and divalent metal ions did not have inhibitory effects.
Use of ESR spectroscopy for the detection of irradiated Crustacea
Authors: Stewart Eileen M , Stevenson M Hilary , Gray Richard
Published: November 2006

Frozen whole tail sections of pink shrimp (Pandalus montagui), tiger prawn (Penaeus monodon), king prawn (Penaeus plebejus) and Mediterranean crevette (Palaemon serratus) were defrosted overnight and either irradiated the following day with doses of 1, 3 and 5 kGy or left unirradiated. Following irradiation the samples were stored for 0, 7,14 or 21 days at 1°C after which the cuticle was removed, freeze‐dried and ground prior to derivation of the electron spin resonance (ESR) spectra. The shape of the ESR signals derived from the irradiated cuticle of the four species were not identical. Subtraction of an average control spectrum from each species from that induced in the corresponding irradiated samples resulted in the isolation of a number of free radical peaks, the heights of which were measured and the sum of the values used as a measure of signal intensity. Both the irradiation dose and length of storage had a highly significant effect on signal intensity. The signal derived from the cuticle of the Mediterranean crevette was the most stable. The isolated radiation‐induced signals from all four species given 3 and 5 kGy were detectable in samples stored at 1°C for at last 14 days.
Comparison of total lipids, fatty acids, sugars and nonvolatile organic acids in nuts from four Castanea species
Authors: Senter Samuel D , Payne Jerry A , Miller Gregory , Anagnostakis Sandra L
Published: November 2006

Total lipid percentage and fatty acid ratios in nuts from Castanea dentata (Marsh) Borkh (American), C sativa Mill (European), C mollissima B1 (Chinese) chestnuts and C pumila (L) Mill (chinkapin) were significantly different among all species and among individuals within species. Total lipids and fatty acids were greatest in American chestnuts followed by chinkapins, then European chestnuts, and lowest in Chinese chestnuts. Palmitic, stearic, oleic, linoleic and linolenic acids comprised the fatty acid complement in all species. Free sugars (fructose, glucose and sucrose) and the sugar‐alcohol inositol did not differ significantly (P > 0.05) by species except in the European chestnuts where fructose and glucose were absent. Citric acid was present in all species except the European chestnuts. Malic acid was present in all species except in the American chestnuts. These results can be used to test nuts of new hybrids being bred for nut orchards and for wildlife mast production.
Isolation of beer foam polypeptides by hydrophobic interaction chromatography and their partial characterisation
Authors: Onishi Akiko , Proudlove Michael O
Published: November 2006

Beer foam polypeptides have been separated into five groups based on their relative hydrophobicity. Foam stability increases with increasing hydrophobicity of the polypeptide groups. The most hydrophobic polypeptide group contains a large proportion of Coomassie blue‐binding polypeptides. Analysis by SDS‐PAGE reveals that each polypeptide group is composed of several differently‐sized polypeptides. Further purification by anion‐exchange chromatography results in five fractions, each of which has a different polypeptide profile on SDS‐polyacrylamide gels.
Use of auxin and cytokinin to regulate anthocyanin production and composition in suspension cultures of strawberry cell
Authors: Mori Tsukasa , Sakurai Miei , Seki Minoru , Furusaki Shintaro
Published: November 2006

The effect of 2, 4‐dichlorophenoxyacetic acid (2,4‐D) and benzyladenine (BA) on the production of anthocyanin and its compositions in suspension callus culture of the leaf tissue from the strawberry (Fragaria ananassa cv Shikinari) were investigated. In order to determine the optimum anthocyanin production in suspension cultures, the effects of cell inoculum size on cell growth and anthocyanin accumulation were also studied. Maximum anthocyanin production was obtained in cultures about 2 weeks old using an inoculum cell size of 2 g. In the early phase of culturing, 2,4‐D stimulated cell growth and impaired anthocyanin accumulation. Approximately 207 μg g−1 cell of anthocyanins was obtained without the need to add phytohormones to the Linsmaier and Skoog (LS) liquid medium to a culture 1 week old, however, greater anthocyanin yield was obtained when 2,4‐D in amounts of more than 0–5 mg litre−1 was added to the LS medium of 2‐week‐old strawberry cultures. The content of two major anthocyanins, cyanidin‐3‐glucoside and peonidin‐3‐glucoside, were influenced by 2,4‐D and BA. The content of cyanidin‐3‐glucoside increased as the both 2,4‐D and BA concentrations rose, and the content when concentrations of 2,4‐D and BA are each 1 mg litre−1 was almost seven times greater than that when no phytohormones were added.
Studies on the recovery of proteinaceous substances from chicken heads: II—Application of pepsin to the production of protein hydrolysate
Authors: Surówka Krzysztof , Fik Mirosław
Published: November 2006

Minced heads of broiler chickens were hydrolysed under various conditions using porcine pepsin. It was found that hydrolysis goes at an optimum rate at 55°C and pH 1.5 following the addition of 750 g water and 3 g pepsin per kg raw material. After 5 h of proteolysis, 1 kg of the raw material yielded 144 g of dry unneutralised hydrolysate containing 15.7 g total nitrogen, equivalent to a 67.8% nitrogen recovery. Neutralisation prior to drying marginally decreased nitrogen recovery and reduced the nitrogen solubility index by >30%. The final dried products were pale cream coloured, had no bitter taste, were of high microbiological quality and had a high mineral content. Both dried hydrolysates had poor emulsifying properties.
Chemiluminescence of fish oils and its flavour quality
Authors: Pettersen J
Published: November 2006

Sodium hypochlorite‐induced and luminol‐sensitised chemiluminescence (CL) of refined, high quality fish oils (FO) have been examined in order to evaluate a sensitive method to determine the flavour quality, ie the rancidity of the oils. Dispensing sodium hypochiorite (NaOCl) into emulsified FO caused a burst of CL and the counts of CL per mg FO increased with the amount of emulsification. The NaOCl induced burst of CL increased with the concentration of NaOCl. CL intensity increased with the temperature and was influenced by O2 in the headspace of the cuvette located in the luminometer. The addition of luminol (Lm) to a concentration of 0.2 μM increased the NaOCl induced CL sevenfold. The deterioration of stored FO samples produced NaOCl induced Lm sensitised CL that increased with storage time and were correlated to the sensory scores. The performance of the CL analysis is simple and rapid (approximately 10 min). The Lm addition improved the sensitivity of NaOCl induced CL and the method is suitable for evaluating the rancidity of refined, high quality fish oils.
Effect of a solid‐state fermentation using Rhizopus oligosporus sp.T‐3 on elimination of antinutritional substances and modification of biochemical constituents of defatted rapeseed meal
Authors: Bau Hwei‐Ming , Villaume Christian , Lin Ching‐Fwu , Evrard Jacques , Quemener Bernard , Nicolas Jean‐Pierre , Méjean Luc
Published: November 2006

A solid‐state fermentation of rapeseed using Rhizopus oligosporus was investigated with the purpose of establishing whether fermentation would result in the elimination of antinutritional substances. A 24 h fermentation induced a degradation of 57.7% aliphatic glucosinolates, 97.3% indol glucosinolates and 73% ethanol‐soluble sugars (α‐gaiactosides, flatulence generator included) of rapeseed meal. The fermented meal had a high protein content (348 g kg−1). A 24 h fermentation resulted in a net increase in aromatic amino acids and ammonia content. The seed hull could be partially predigested by the enzymes secreted by the mould. The fermentation did not improve the protein efficiency ratio (PER). Rats fed fermented meal had a thyroid weight similar to those of rads fed casein. The protein intake of rats fed fermented meal diet was identical to that of rats fed the dehulled, defatted and heated meal diet. If the combined effects were taken into account, it would appear that the fermentation improved greatly the biological and nutritional value of the obtained products.
Composition and quality characteristics of sesame seed (Sesamum indicum) oil roasted at different temperatures in an electric oven
Authors: Yoshida Hiromi
Published: November 2006

The quality characteristics of sesame oils prepared at different roasting temperatures (120–250°C) from sesame seeds using a home electric oven were compared with an unroasted oil sample: only minor increases (P < 0.05) in characteristics, such as acid value, peroxide value, anisidine value and thiobarbituric acid value, of sesame oils occurred in relation to increasing roasting temperature between 120 and 180°C, but colour increase was more pronounced. In the oil prepared using a 250°C roasting temperature, the glycolipid content per 1000 seeds increased markedly (262.9 mg) compared with unroasted oil (6.9 mg) and phospholipids were no longer detectable. The fatty acid content of the oil was reduced, reflecting an increase in glycolipid content and triglyceride oxidation/polymerisation when the roasting temperature was over 220°C but fatty acid composition was unchanged. The amounts of γ‐tocopherol and sesamolin still remained over 900 g kg−1 of the original level after roasting at 180°C, but were almost depleted at 250°C Sesame oil prepared using a 180°C roasting temperature had the best flavour score when compared with the other samples.