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Mg G (mg + g)

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Chemistry	54%
Life Sciences	30%
Earth and Environmental Science	8%
Medical Sciences	5%

Distribution within Chemistry

General & Introductory Food Science & Technology	51%
Chemical Engineering	40%
2 Other Subdomains	9%

Selected Abstracts

Effect of Zn deficiency and subsequent Zn repletion on bone mineral composition and markers of bone tissue metabolism in 65Zn-labelled, young-adult rats

JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 7-8 2002
W. Windisch
Summary The objective of the present study was to investigate the effect of changing skeletal Zn load (mobilization/restoring) on bone mineral composition and bone tissue metabolism. For this purpose, 36 65Zn-labelled, young-adult female rats were fed with either a purified diet with sufficient Zn (21 ,g/g, control) for 26 days, or deficient Zn (1.4 ,g/g) for 12 days followed by 14 days repletion with the control diet. The animals were killed at the onset of the study (reference: n=4), at the end of the Zn deficiency episode (control: n=4; Zn deficiency: n=4), subgroups (n=4) of Zn repleted animals at repletion days 2, 4, 7, 10 and 14, and at day 14 the remaining controls also (n=4). Zn deficiency reduced skeletal Zn concentration from 198 to 155 ,g/g of bone dry matter. About half of mobilized skeletal Zn was refilled within 2 days of repletion and was completely restored until the end of the study. Concentrations of bone ash, Ca, P and Mg remained constant (means in bone dry matter: 51% bone ash, 191 mg Ca/g, 95 mg P/g, 4.4 mg Mg/g). Blood plasma concentrations of osteocalcin and daily urinary excretions of pyridinoline PYD and dexoxypyridinoline DPD were unaffected by treatment (mean: 57 ng/ml, 222 nmol/day, 137 nmol/day). Also daily urinary excretions of Ca, P and Mg remained fairly constant (means: 0.26 mg/day, 16 mg/day, 1.5 mg/day). 65Zn autoradiography of femur sections revealed a pronounced Zn exchange in the area of the metaphysis and epiphysis. We conclude that transient mobilization and restoration of skeletal Zn occurs mainly in trabecular bone, and does not involve major changes in bone mass, macro mineral content, or bone tissue turnover in young-adult rats. [source]

Determination of iodide using flow injection with acidic potassium permanganate chemiluminescence detection

LUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 4 2006
Mohammad Yaqoob
Abstract A simple and rapid flow-injection method is described for the determination of iodide, based on potassium permanganate chemiluminescence detection via oxidation of formaldehyde in aqueous hydrochloric acid. The calibration graph was linear over the range 1.0,12 × 10,6 mol/L (r2 = 0.9955) with relative standard deviations (n = 4) in the range 1.0,3.5%. The detection limit (3,) was 1.0 × 10,7 mol/L, with sample throughput of 120/h. The effect of interfering cations [Ca(II), Mg(II), Ni(II), Fe(II), Fe(III) and Pb(II)] and anions (Cl,, SO42,, PO43,, NO3,, NO2,, F, and SO32,) were studied. The method was applied to iodized salt samples and the results obtained in the range 0.03 ± 0.005,0.10 ± 0.006 mg I/g were in reasonable agreement with the amount labelled. The method was statistically compared with the results obtained by titration; no significant disagreement at 95% confidence was observed. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Effects of additives on oxidation characteristics of palm oil-based trimethylolpropane ester in hydraulics applications

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 4 2009
Nor Halaliza Alias
Abstract Hydraulic fluids represent one of the most important groups of industrial lubricants. Increasing attention to environmental issues drives the lubricant industry to choose vegetable-based hydraulic fluids which are biodegradable as compared to mineral-based fluids. However, the lubricating properties of vegetable oil, such as poor oxidative stability and high pour point, have hindered their use. In this study, trimethylolpropane ester, which was derived from palm-based methyl ester, was used as the base hydraulic fluid. The purpose of the study was to determine the optimum formulation for palm oil-based synthetic lubricants by using suitable additives that can improve the oxidative stability and viscosity in accordance with the standard regulations for hydraulic fluid applications. The oxidative stability of the oil was evaluated by total acid number (TAN) and viscosity tests. In general, base oil without additive began to degrade after 200,h. The formulated oil, on the other hand, was quite stable even after 800,h of operation. The best formulation was obtained using 1.0% of either additive,A or additive,B. Both TAN and viscosity values were found to increase with increasing heating temperature. Meanwhile, the results have also shown that additive,A performs better than additive,B. After 800,h of exposure, the final TAN value for the formulated oil was only at 0.32 as compared to 4.88,mg KOH/g for the oil without additive. However, the kinematic viscosity of the oil at 40 and 100,°C was almost unchanged as compared to the oil without additive. [source]

Effect of Zn deficiency and subsequent Zn repletion on bone mineral composition and markers of bone tissue metabolism in 65Zn-labelled, young-adult rats

Effects of Whey Permeate-Based Medium on the Proximate Composition of Lentinus edodes in the Submerged Culture

JOURNAL OF FOOD SCIENCE, Issue 6 2006
Xiaojun Jeffrey Wu
ABSTRACT:, Biomass production, crude water-soluble polysaccharide (WSP), ash content, mineral profile, and crude protein content were determined for Lentinus edodes mycelia grown on whey permeate (WP)-based medium with lactose content of 4.5% or defined synthetic medium, and harvested after 5, 10, 15, or 20 d of fermentation at 25 °C. Harvesting time and the type of media interact to alter the chemical content of mycelia. Mycelia grown in WP had greater (P < 0.05) WSP and ash than mycelia grown in the synthetic media. A maximum production of WSP was obtained on the 10th day (4.1 × 102± 71 mg WSP/g dried mycelia) from mycelia grown on the WP-based media. Mycelia grown on WP harvested on the 20th day had the highest value in ash content (18 ± 3%). Potassium was found to be the main constituent in the ash of mushroom mycelia, which was followed by phosphorus, sodium, calcium, and magnesium. A steady increase of ash content was only noted in mycelia grown on WP. The calcium content of WP-grown mycelia was at least 10 times higher compared to mycelia grown in the control media regardless the harvesting time. Data in this research suggested that WP was more favorable than the synthetic media in the production of WSP, which is traditionally known for their medicinal value in L. edodes. [source]

Spleen lymphocyte function modulated by a cocoa-enriched diet

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2007
E. Ramiro-Puig
Summary Previous studies have shown the down-regulating in vitro effect of cocoa flavonoids on lymphocyte and macrophage activation. In the present paper, we report the capacity of a long-term rich cocoa diet to modulate macrophage cytokine secretion and lymphocyte function in young rats. Weaned rats received natural cocoa (4% or 10% food intake), containing 32 mg flavonoids/g, for 3 weeks. Spleen immune function was then evaluated through the analysis of lymphocyte composition, their proliferative response and their ability to secrete cytokines and Ig. In addition, the status of activated peritoneal macrophages was established through tumour necrosis factor (TNF)-, secretion. The richest cocoa diet (10%) caused a reduction of TNF-, secretion by peritoneal macrophages showing anti-inflammatory activity. Similarly, although a 10% cocoa diet increased lymphocyte proliferation rate, it down-regulated T helper 2 (Th2)-related cytokines and decreased Ig secretion. These changes were accompanied by an increase in spleen B cell proportion and a decrease in Th cell percentage. In summary, these results demonstrate the functional activity of a cocoa-high dosage in down-regulating the immune response that might be beneficial in hypersensitivity and autoimmunity. [source]

Predicting pasture root density from soil spectral reflectance: field measurement

EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2010
B. H. KUSUMO
This paper reports the development and evaluation of a field technique for in situ measurement of root density using a portable spectroradiometer. The technique was evaluated at two sites in permanent pasture on contrasting soils (an Allophanic and a Fluvial Recent soil) in the Manawatu region, New Zealand. Using a modified soil probe, reflectance spectra (350,2500 nm) were acquired from horizontal surfaces at three depths (15, 30 and 60 mm) of an 80-mm diameter soil core, totalling 108 samples for both soils. After scanning, 3-mm soil slices were taken at each depth for root density measurement and soil carbon (C) and nitrogen (N) analysis. The two soils exhibited a wide range of root densities from 1.53 to 37.03 mg dry root g,1 soil. The average root density in the Fluvial soil (13.21 mg g,1) was twice that in the Allophanic soil (6.88 mg g,1). Calibration models, developed using partial least squares regression (PLSR) of the first derivative spectra and reference data, were able to predict root density on unknown samples using a leave-one-out cross-validation procedure. The root density predictions were more accurate when the samples from the two soil types were separated (rather than grouped) to give sub-populations (n = 54) of spectral data with more similar attributes. A better prediction of root density was achieved in the Allophanic soil (r2 = 0.83, ratio prediction to deviation (RPD ) = 2.44, root mean square error of cross-validation (RMSECV ) = 1.96 mg g ,1) than in the Fluvial soil (r2 = 0.75, RPD = 1.98, RMSECV = 5.11 mg g ,1). It is concluded that pasture root density can be predicted from soil reflectance spectra acquired from field soil cores. Improved PLSR models for predicting field root density can be produced by selecting calibration data from field data sources with similar spectral attributes to the validation set. Root density and soil C content can be predicted independently, which could be particularly useful in studies examining potential rates of soil organic matter change. [source]

Chronic effects of type 2 diabetes mellitus on cardiac muscle contraction in the Goto-Kakizaki rat

EXPERIMENTAL PHYSIOLOGY, Issue 6 2007
F. C. Howarth
Type 2 diabetes mellitus accounts for more than 90% of all cases of diabetes mellitus, and cardiovascular complications are the major cause of mortality and death in diabetic patients. The chronic effects of type 2 diabetes mellitus on heart function have been investigated in the Goto-Kakizaki (GK) rat. Experiments were performed in GK rats and age-matched Wistar control rats at 18 months of age. The progressive effects of diabetes on glucose metabolism were monitored periodically by application of the glucose tolerance test. Ventricular action potentials were measured in isolated, perfused heart. Shortening and intracellular Ca2+ were measured in electrically stimulated ventricular myocytes. The GK rats displayed mild fasting hyperglycaemia and progressively worsening glucose tolerance. At 18 months of age and 180 min after intraperitoneal injection of glucose (2 g (kg body weight),1), blood glucose was 436 ± 47 mg dl,1 in GK rats compared with 153 ± 18 mg dl,1 in control animals. Heart weight to body weight ratio was significantly increased in GK rats (4.10 ± 0.09 mg g,1, n= 5) compared with control animals (3.36 ± 0.22 mg g,1, n= 4). Spontaneous heart rate was slightly reduced in GK rats compared with control rats. Although the amplitude of shortening was not altered, the amplitude of the Ca2+ transient was significantly increased in myocytes from GK rats (0.78 ± 0.11 ratio units) compared with control rats (0.50 ± 0.06 ratio units). Despite progressively worsening glucose metabolism, at 18 months of age the contractile function of the heart appears to be well preserved. [source]

Effect of Losartan on Sodium Appetite of Hypothyroid Rats Subjected to Water and Sodium Depletion and Water, Sodium and Food Deprivation

EXPERIMENTAL PHYSIOLOGY, Issue 5 2001
D. Badauê-Passos Jr
The involvement of angiotensin AT1 receptors in sodium appetite was studied in hypothyroid rats treated with the angiotensin II antagonist losartan. Losartan was administered chronically by the oral route or acutely by the subcutaneous route after water and sodium depletion or water, sodium and food deprivation. Three days after addition of losartan to the food at the dose of 1.0 mg g,1, the rats significantly reduced (P < 0.02) their spontaneous intake of 1.8% NaCl. Increasing the dose of losartan to 2.0 and 4.0 mg g,1 did not reduce NaCl intake; in contrast, the intensity of the sodium appetite gradually returned to previous levels. The simultaneous administration of captopril, an angiotensin converting enzyme inhibitor, and losartan significantly increased (P < 0.05) NaCl intake and after captopril removal NaCl intake returned to the levels observed with losartan treatment alone. The administration of losartan 4 days after the beginning of captopril treatment significantly reduced (P < 0.0001) NaCl intake. Following acute administration of losartan, water- and sodium-depleted rats significantly reduced their NaCl and water intake (P < 0.001). The administration of losartan also induced a significant reduction in NaCl and water intake in water, NaCl and food-deprived rats (P < 0.0001 and P < 0.001, respectively). The present results show that chronic treatment with oral losartan inhibited spontaneous sodium appetite in hypothyroid rats. Continuation of treatment rendered rats resistant to the blockade of AT1 receptors. Water and sodium depletion and water, NaCl and food deprivation induced sodium appetite, which in the short term depends on cerebral angiotensinergic activity mediated by the activation of AT1 receptors. [source]

Lead and cadmium uptake in the marine fungi Corollospora lacera and Monodictys pelagica

FEMS MICROBIOLOGY ECOLOGY, Issue 3 2005
Michael A.S. Taboski
Abstract This study provides observations on the effects of lead and cadmium ions on the growth of two species of marine fungi, Corollospora lacera and Monodictys pelagica. On solid media lead appeared to have no effect on the radial rate of growth of fungi. Exposure to increasing cadmium concentrations on solid media resulted in significant reduction (P < 0.05) in the radial mycelial growth rates of both fungi, especially in M. pelagica. These results reveal significant difference in species sensitivity toward cadmium and, essentially, insensitivity toward lead exposure. In liquid cultures, the metal content of mycelia (metal mass found in mycelium, in mg), and the concentration of metal in dry mycelium (metal mass in 1 g of mycelium, in mg g,1) were both found to increase (P < 0.05) with the increase in the metal cation concentration, while mycelium dry mass decreased. As it was observed on solid media, cadmium cation affected more severely (P < 0.05) the growth of M. pelagica in liquid cultures. Ergosterol content of mycelia of C. lacera exposed to increasing cadmium cation concentration decreased, similarly to the trend observed for dry mycelial mass. It was found that ca. 93% of all lead sequestered by C. lacera is located extracellularly. M. pelagica was found to bioaccumulate over 60 mg of cadmium and over 6 mg of lead per 1 g of mycelium, while C. lacera bioaccumulated over 7 mg of cadmium and up to 250 mg of lead per 1 g of mycelium. Overall, the results indicate that both metal ions affect the growth of marine fungi with lead being accumulated extracellularly in the mycelia. Both metals accumulated by fungi may then enter the marine ecosystem food web, of which marine fungi are integral members. [source]

Respiration and annual fungal production associated with decomposing leaf litter in two streams

FRESHWATER BIOLOGY, Issue 9 2004
M. D. Carter
Summary 1. We compared fungal biomass, production and microbial respiration associated with decomposing leaves in one softwater stream (Payne Creek) and one hardwater stream (Lindsey Spring Branch). 2. Both streams received similar annual leaf litter fall (478,492 g m,2), but Lindsey Spring Branch had higher average monthly standing crop of leaf litter (69 ± 24 g m,2; mean ± SE) than Payne Creek (39 ± 9 g m,2). 3. Leaves sampled from Lindsey Spring Branch contained a higher mean concentration of fungal biomass (71 ± 11 mg g,1) than those from Payne Creek (54 ± 8 mg g,1). Maximum spore concentrations in the water of Lindsay Spring Branch were also higher than those in Payne Creek. These results agreed with litterbag studies of red maple (Acer rubrum) leaves, which decomposed faster (decay rate of 0.014 versus 0.004 day,1), exhibited higher maximum fungal biomass and had higher rates of fungal sporulation in Lindsey Spring Branch than in Payne Creek. 4. Rates of fungal production and respiration per g leaf were similar in the two streams, although rates of fungal production and respiration per square metre were higher in Lindsey Spring Branch than in Payne Creek because of the differences in leaf litter standing crop. 5. Annual fungal production was 16 ± 6 g m,2 (mean ± 95% CI) in Payne Creek and 46 ± 25 g m,2 in Lindsey Spring Branch. Measurements were taken through the autumn of 2 years to obtain an indication of inter-year variability. Fungal production during October to January of the 2 years varied between 3 and 6 g m,2 in Payne Creek and 7,27 g m,2 in Lindsey Spring Branch. 6. Partial organic matter budgets constructed for both streams indicated that 3 ± 1% of leaf litter fall went into fungal production and 7 ± 2% was lost as respiration in Payne Creek. In Lindsey Spring Branch, fungal production accounted for 10 ± 5% of leaf litter fall and microbial respiration for 13 ± 9%. [source]

Breakdown of wood in the Agüera stream

FRESHWATER BIOLOGY, Issue 11 2002
Joserra Díez
SUMMARY 1. Breakdown of wood was compared at three sites of the Agüera catchment (Iberian Peninsula): two oligotrophic first-order reaches (one under deciduous forest, the other under Eucalyptus globulus plantations) and one third-order reach under mixed forest, where concentration of dissolved nutrients was higher. 2. Branches (diameter = 3 cm, length = 10 cm) of oak (Quercus robur), alder (Alnus glutinosa), pine (Pinus radiata) and eucalyptus, plus prisms (2.5 × 2.5 × 10 cm) of alder heartwood were enclosed in mesh bags (1 cm mesh size) and placed in the streams. Mass loss was determined over 4.5 years, whereas nutrient, lignin and ergosterol were determined over 3 years. In order to describe fungal dynamics, ergosterol was also determined separately on the outer and inner parts of some branches. 3. Breakdown rates ranged from 0.0159 to 0.2706 year,1 with the third-order reach having the highest values whatever the species considered. The most rapid breakdown occurred in alder heartwood and the slowest in pine branches; breakdown rates of oak, eucalyptus and alder branches did not differ significantly. 4. The highest nitrogen and phosphorus contents were found in alder, followed by oak, while pine and eucalyptus had low values. During breakdown, all materials rapidly lost phosphorus, but nitrogen content remained constant or slightly increased. Lignin content remained similar. 5. Peaks of ergosterol ranged from 0.023 to 0.139 mg g,1 and were higher in alder than in other species in two of the three sites. The third-order reach generally had the greatest increase in ergosterol, especially in alder branches, eucalyptus and alder heartwood. The overall species/site pattern of fungal biomass was thus consistent with the observed differences in breakdown. 6. When compared with leaves of the same species decomposing at these sites, wood breakdown appeared to be less sensitive to the tree species but more sensitive to stream water chemistry. Although wood breakdown is slower and its inputs are lower than those of leaf litter, its higher resistance to downstream transport results in a relatively high standing stock and a significant contribution to the energy flux. [source]

Plant palatability and disturbance level in aquatic habitats: an experimental approach using the snail Lymnaea stagnalis (L.)

FRESHWATER BIOLOGY, Issue 5 2002
ARNAUD ELGER
1.,The palatability of aquatic macrophytes to the snail Lymnaea stagnalis was investigated in the laboratory. Eight species of macrophyte were selected from habitats that differed in either flood disturbance regime or nutrient status. 2.,In a non-choice test, single macrophyte species were offered to individual snails. The average amount of plant dry mass consumed per Lymnaea dry mass ranged from 3.6 ± 1.4 (±SE) to 63.6 ± 13.9 mg g,1 day,1 across plant species. In a choice test, all eight plant species were presented simultaneously to sets of five snails. The average total consumption was 66.1 ± 3.8 mg g,1 day,1 and the maximum average consumption for a single plant was 26.2 ± 3.6 mg g,1 day,1. 3.,In both tests, the amount consumed by snails differed significantly between the plant species. The species growing in undisturbed habitats were the least consumed. Habitat nutrient status was unrelated to plant palatability. 4.,These results suggest that macrophyte species growing in habitats that are rarely disturbed by floods allocate a greater proportion of their resources to resisting herbivory. [source]

DPPH free-radical scavenging ability, total phenolic content, and chemical composition analysis of forty-five kinds of essential oils

INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 6 2009
H.-F. Wang
J. Cosmet. Sci., 59, 509,522 (November/December 2008) Synopsis Forty-five kinds of commonly used essential oils were employed to investigate the DPPH (1,1-diphenyl2-picrylhydrazyl) radical scavenging ability and total phenolic content of major chemical compositions. The free-radical scavenging ability and total phenolic content of cinnamon leaf and clove bud essential oils are the best among these essential oils. One-half milliliter of cinnamon leaf and clove bud essential oils (10 mg mL EtOH) are shown to be 96.74% and 96.12% of the DPPH (2.5ml, 1.52 × 10 -4 M) free-radical scavenging ability, respectively. Their EC50 (effective concentrations) are 53 and 36 (,g mL -1). One milligram per milliliter of cinnamon leaf, clove bud, and thyme red essential oils were shown to be 420, 480, and 270 (mg g -1 of GAE) of total phenolic content, respectively. Eugenol in cinnamon leaf and clove bud essential oils (82.87% and 82.32%, respectively) were analyzed by GC-MS. It is clear that the amounts of the phenol compounds in essential oils and the DPPH free-radical scavenging ability are in direct proportion. [source]

Antioxidants in aerial parts of Hypericum sampsonii, Hypericum japonicum and Hypericum perforatum

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 11 2009
Chung Li Chen
Summary Antioxidants contents and antioxidative enzymes and their activities in fresh aerial tissues of Hypericum sampsonii (Sampson's St John's Wort), Hypericum japonicum (Japanese St John's Wort) and Hypericum perforatum were investigated. Hypericum sampsonii contained more total ascorbate [34.33 ,mol g,1 fresh weight (FW)] than H. perforatum (57% less) and H. japonicum (82% less). It also contained more thiol and phenolics than two other species. Hypericum japonicum had highest superoxide dismutase (SOD) activity (8.74 mmol min,1 g,1 FW), followed by H. sampsonii (2% less) and H. perforatum (37% less). Hot-air dried H. perforatum materials contained more thiol [208.7 ,mol g,1 dry weight (DW)] and phenolics (352.82 mg g,1 DW) than freeze-dried and fresh materials. Both drying treatments decreased the activities of antioxidative enzymes in aerial tissues of H. perforatum. However, freeze-dried H. perforatum contained the highest SOD activity (5.42 mmol min,1 g,1 DW) among the antioxidative enzymes measured from both freeze-dried and hot-air dried tissues (ranged from 0.02 to 2.65 ,mol min,1 g,1 DW). [source]

Biochemical changes in cut vs. intact lamb's lettuce (Valerianella olitoria) leaves during storage

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2009
Antonio Ferrante
Summary Consumers are oriented towards fresh-cut vegetables that provide phytonutrients useful for preventing stress-related diseases. The aim of this work was to evaluate the cut operations on the quality changes of lamb's lettuce (Valerianella olitoria L.) cv. Trofy during storage at 4 °C for 8 days. Results showed that chlorophyll and carotenoids reduction was observed after 8 days of storage. In both treatments, total carotenoids after 8 days decreased from 20 to 16 mg g,1 FW. Free and total phenols increased with storage in both treatments. Total phenols were 23% higher in control (32 ,mol g,1 FW) compared to cut leaves (25 ,mol g,1 FW) after 8 days of storage. Anthocyanins increased after 8 days and reached 30 mg 100 g,1 FW without significant difference between treatments. Ascorbic acid (AsA) and dehydroascorbic (DHA) acid increased in cut leaves compared to control. After 1 day AsA concentration was 3 300 nmol g,1 FW in cut leaves, while in control leaves was 1 500 nmol g,1 FW. Analogously AsA + DHA was higher in cut leaves, 4 100 nmol g,1 FW, while in control leaves the mean was 3 000 nmol g,1 FW. After 5 days of storage the values of AsA returned to initial values, while AsA + DHA were lower. [source]

Storage stability of a high dietary fibre powder from orange by-products

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2009
Juana Fernández-López
Summary The goal of this investigation was to evaluate the effects of storage time and conditions on the physicochemical and microbiological properties of a high dietary fibre powder (HDFP). HDFP for this study was manufactured from orange juice industry by-products. The storage period was 11 months and samples were stored under vacuum or air exposure and under dark or light exposure. The HDFP is a stable product (based on chemical, microbiological and physicochemical properties) with large amounts of dietary fibre (71.62 ± 0.24 g 100 g,1 dry sample) and polyphenols content (40.67 ± 0.45 mg g,1 dry sample). Hesperidin is the major compound identified in HDFP (higher than 50% of total phenolic compounds). The packaging material used protects the HDFP only up to 6 months. After this time, the increase in moisture content decreases the quality of the product. The best storage conditions are packaging under vacuum and darkness. Both conditions preserve the colour of the fibres probably by means of avoiding pigment degradation. [source]

Composition and functional properties of raw and electron beam-irradiated Mucuna pruriens seeds

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2008
Rajeev Bhat
Summary The proximate, nutritional and functional properties of raw and electron beam-irradiated (0,30 kGy) Mucuna seeds were investigated. Irradiation increased crude protein and crude carbohydrates significantly than crude lipid, crude fibre and energy. Raw seeds were rich in minerals and were not affected by irradiation except for magnesium and phosphorus. Amino acids of raw seeds were comparable to soyabean and FAO/WHO reference pattern and except for 30 kGy, no significant changes were seen in amino acid profile. Raw seeds were rich in unsaturated fatty acids and some of them decreased on irradiation, while linoleic acid steadily elevated (0,14.35 mg g,1 lipid). In vitro protein digestibility was dose dependent and significantly increased up to 15 kGy. Water and oil absorption capacities and foaming capacity significantly increased on irradiation, while protein solubility decreased (15 and 30 kGy) with an improvement of gelation property of seed flour. The cooking time of seeds significantly reduced on irradiation. [source]

Antioxidant properties of methanolic extracts from different parts of Sclerocarya birrea

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2008
Abdalbasit A. Mariod
Summary The methanolic extracts from Sclerocarya birrea leaves (SCL), roots (SCR), barks (SCB), and kernel oil cake (SCK) were examined for radical scavenging capacities and antioxidant activities. The total phenolics of the extracts was determined spectrophotometrically according to the Folin-Ciocalteau method using gallic acid as standard solution. The total phenolic compounds were found as 304.5, 367.5, 593, 148.0 and 258.0 mg g -1 of dry product, respectively. The extracts of SCL, SCR, SCB and SCK were markedly effective in inhibiting the oxidation of linoleic acid and subsequent bleaching of ,-carotene in comparison with the control. Based on oxidation of ,-carotene/linoleic acid, the SCK extract is the most effective followed by SCR, SCL and SCB extract. The antioxidant activity determined by the DPPH (1,1-diphenyl-,-picrylhydrazyl) method revealed that the SCK extract had the highest antioxidant activity on DPPH free radicals followed by SCB, SCR and SCL extracts. The effect of different extracts on the oxidative stability of sunflower oil at 70 °C was tested in the dark and compared with BHA. The oil peroxide values (PVs) were generally lower with the addition of extract in comparison to a control. [source]

Effect of cream treatment on phospholipids and protein recovery in butter-making process

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2008
Michel Britten
Summary A simple approach is proposed to recover native protein and phospholipid fractions from butter-making process using equipments available in dairy-processing plant. A washing treatment was used to remove protein from the cream and increase the phospholipids purity in buttermilk. Cream from a first separation was diluted with milk ultrafitration permeate and separated a second time. A 10X dilution factor reduced protein concentration in the cream from 1.6 ± 0.2 to 0.52 ± 0.03%. As a result, the phospholipids to protein ratio in buttermilk increased from 53 ± 10 to 172 ± 7 mg g,1. In butter-making process, an important portion of total phospholipids (,26%) is retained in butter. Butter serum made from washed cream could then be used to produce phospholipid concentrates with phospholipids to protein ratio of 473 ± 3 mg g,1. Interestingly, the extracts from butter serum are characterised by a higher proportion of sphingomyelin compared with those from buttermilk. [source]

Chemical composition and toxic trace element composition of some Nigerian edible wild mushrooms

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2008
Olumuyiwa S. Falade
Summary Two essential amino acids (methionine and tryptophan); anti-nutritional factors (tannin and trypsin inhibitor) and toxic elements (Pb, Cd, Ni, As, Hg and Cr) were determined spectrophotometrically from five edible wild mushrooms. The tryptophan content was between 1.00 and 1.82 g (100 g),1 but methionine was low at 0.26,1.38 g (100 g),1. Tannin content was high (30.3,40.0 mg g,1) but trypsin inhibitor was low (22.0,39.5 TIU g,1). Trace elements analysis reviled Pb (0.34,5.06 mg kg,1) to be the highest of all the trace elements. Cd was (0.06,1.70 mg kg,1), Ni (0.26,2.08 mg kg,1), As (0.17,0.92 mg kg,1), Hg (0.01,0.05 mg kg,1) and Cr (0.04,0.22 mg kg,1). These mushrooms are nutritious but must be well processed to eliminate or at least reduce the levels of tannin and Pb to improve their nutritional values. [source]

Effect of particle size and drying temperature on drying rate and oil extracted yields of Buccholzia coriacea (MVAN) and Butyrospermum parkii ENGL

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2007
César Kapseu
Summary The effect of particle size and drying temperature on drying rate and oil extracted yields of Buccholzia coriacea (MVAN) and Butyrospermum parkii (ENGL) was investigated. Air drying studies carried out on B. coriacea and B. parkii, tropical food sources subject to high post-harvest losses, have resulted in the establishment of a significant difference between oil yields extracted from samples of various particle size pretreatments (paste, 4 mm, 8 mm and whole kernels) dried at 45 and 60 °C with the highest oil yield given by the 4 mm thick slices dried at 45 °C. The influence of temperature and particle thickness on the drying rate has been evaluated. The drying constants were found to depend on both temperature and particle thickness. Analysis of the oil extracted from the 4 mm thick slices dried at 45 °C showed that apart from the acid value (52.4%), the saponification (181.2 mg g,1 KOH), peroxide (8.6 meq kg,1) and the unsaponifiable (7.43%) matter values of the extracted shea butter remain within the limits cited in the literature while a close analysis of the cake suggests that it could be a good mineral source. [source]

Chemical components of Aspergillus -type Douchi, a Chinese traditional fermented soybean product, change during the fermentation process

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2007
Jian-Hua Zhang
Summary Douchi, a traditional fermented soybean product that originated in China, has been consumed since ancient times as a food seasoning. The influence of fermentation on the chemical components of naturally fermented douchi and Aspergillus egypticus pure-cultured douchi was investigated. Changes in per cent and/or concentration of amino-type nitrogen, total acid, reducing sugar, organic acid, amino acids (AA) and isoflavone, along with the neutral protease and , -glucosidase activities during the fermentation, were analysed. The results indicated that fermentation had a significant effect on the concentration of chemical components. The concentration of all free amino acids (FAA) increased gradually during fermentation, to a maximum of 109.54 mg g,1 in 15-day fermented products. The main organic acids in douchi are 7.788 and 17.778 mg g,1, respectively. During fermentation, the contents of daidzin and genistin decreased from 160.7 and 207.9 to 7.54 and 24.12 ,g g,1 respectively. Daidzein and genistein increased from 18.2 and 16.9 to 63.4 and 84.6 ,g g,1, respectively. [source]

The effect of hydration time and ethanol concentration on the rate of hydrolysis of extracted vanilla beans by commercial cellulase preparations

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2005
Sandy L. Ovando
Summary The rate of producing reducing sugars from extracted vanilla beans by using cellulolytic enzymes was studied. The hydration of cellulose improved the efficiency of hydrolysis. The treatment using Crystalzyme PML-MX at a concentration of 2.64 International Filter Paper Units (IFPU) g,1 of bean was the most successful and the enzyme stable for up to 5:100 (weight:volume) of ethanol. After 48 h of prehydration and 26 h of enzymatic hydrolysis with this enzyme preparation, 196.6 mg g,1 reducing sugars containing 15.9 mg g,1 glucose were liberated. Less active enzyme products, Zymafilt L-300 and Novozym, had greater cellulolytic activity when 10 or 15:100 (weight:volume) of ethanol were added respectively. Because of their stability with ethanol, the enzyme products could be used in the pretreatment of botanical material that are rich in flavour compounds and in this manner improve the final extraction of valuable flavours. [source]

Leaf Decomposition in a Mountain Stream in the Sultanate of Oman

INTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 1 2009
Maha Al-Riyami
Abstract Decomposition of Juglans regia leaves was studied in fine and coarse mesh bags in a permanent mountain stream in Oman. A rapid initial mass loss, attributed to leaching, was followed by a more gradual decline. Daily exponential decay rates (k) calculated over 32 days were 0.011 (fine mesh litter bags) and 0.014 (coarse mesh litter bags). The difference between bag types was not significant, suggesting limited impact of leaf-shredding invertebrates. Ergosterol levels on leaves from fine mesh bags peaked at 0.3 mg g,1 AFDM after 16 days of stream exposure. During the experimental period, which followed the annual leaf fall, the concentration of aquatic hyphomycete conidia in the stream varied between 82 and 1362 l,1. Based on the morphology of conidia found in the water column or released from leaves, we identified 14 species of aquatic hyphomycetes. Tetracladium apiense was the most common taxon (62.2% of conidia in water column during the field experiment). Three other Tetracladium species contributed another 8%. Plating out leaf particles yielded common epiphytic taxa such as Alternaria sp., Aureobasidium pullulans and Phoma sp. The measured metrics of leaf decay in this desert stream fall within the range of values observed in temperate and tropical streams, with clear evidence for an early leaching phase, and no evidence of a strong impact of leaf shredders. The community of aquatic hyphomycetes appears impoverished. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Changes in amino acid composition in the tissues of African catfish (Clarias gariepinus) as a consequence of dietary L-carnitine supplements

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2002
R. O. A. Ozório
A study was undertaken to examine the effect of different amounts of dietary lysine (13 and 21 g kg,1 diet), lipid (80 and 160 g kg,1 diet) and L -carnitine (0.2 and 1.0 g kg,1 diet) on growth performance, proximate composition and amino acid metabolism of the African catfish (Clarias gariepinus). Juvenile African catfish (23 ± 1.5 g/fish) were stocked into 70-L aquaria (16 aquaria, 28 fish/aquarium) connected to a recirculation system during a maximum period of 74 days. All groups were fed at a level of 24 g kg,0.8 day,1 in an experiment run at pair feeding. Animals receiving 1.0 g carnitine accumulated up to six times more carnitine in their tissues than animals receiving 0.2 g (P < 0.05). Acyl-carnitine and free L -carnitine levels increased in the whole body and in tissues. Dietary L -carnitine supplements increased protein-to-fat ratios in the body, but did not affect growth rate. Protein-to-fat ratios were only affected when the biosynthesis capacity of L -carnitine was restricted due to low lysine levels and when there was a shortage of dietary fat. When lysine was offered at 21 g kg,1 feed, dietary L -carnitine supplements did not affect the amino acid concentrations of body tissues. Dietary L -carnitine supplements raised the concentration of glutamic acid,>,aspartic acid,>,glycine > alanine > arginine > serine > threonine in skeletal muscle tissue (P < 0.05). Total amino acid concentration in muscle and liver tissues (dry-matter basis) increased from 506 to 564 and from 138 to 166 mg g,1, respectively, when diets were offered with high L -carnitine, low lysine and low fat levels. These data suggest that dietary L -carnitine supplementation may increase fatty acid oxidation and possibly decrease amino acid combustion for energy. [source]

Palladium and platinum sorption on a thiocarbamoyl-derivative of chitosan

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010
A. Butewicz
Abstract Immobilizing thiourea onto chitosan allowed using the polymer for the recovery of platinum groups metals (PGMs) in acidic solutions (up to 1,2M HCl concentrations). At low HCl concentration protonated amine groups may sorb chloroanionic metal species (electrostatic attraction mechanism); however, most of sorption proceeds through chelation on sulfur containing groups (less sensitive to acidic conditions). The bi-site Langmuir equation was used for fitting sorption isotherms. The sorption of PGMs was weakly affected by the composition of the solution (presence of high concentration of anions and base metals). Maximum sorption capacities for Pd(II) and Pt(IV) ranged between 274 and 330 mg g,1 in 0.25M HCl solutions and decreased to 150,198 mg g,1 in 2M HCl solutions: Pd(II) sorption was systematically higher than Pt(IV) sorption. The pseudo-second rate equation was used for modeling the uptake kinetics. Agitation speed hardly affected uptake kinetics indicating that external diffusion resistance is not the rate controlling step. Desorption yield higher than 85% were obtained using thiourea in 0.1M HCl solution. The adsorbents could be reused for at least three cycles. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Sorption of copper by a highly mineralized peat in batch and packed-bed systems

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2010
Marta Izquierdo
Abstract BACKGROUND: The performance of peat for copper sorption was investigated in batch and fixed-bed experiments. The effect of pH was evaluated in batch experiments and the experimental data were fitted to an equilibrium model including pH dependence. Hydrodynamic axial dispersion was estimated by tracing experiments using LiCl as a tracer. Six fixed-bed experiments were carried out at copper concentrations between 1 and 60 mg dm,3 and the adsorption isotherm in dynamic mode was obtained. A mass transport model including convection,dispersion and sorption processes was applied for breakthrough curve modelling. RESULTS: Maximum uptake capacities in batch mode were 22.0, 36.4, and 43.7 mg g,1 for pH values of 4.0, 5.0, and 6.0, respectively. Uptake capacities in continuous flow systems varied from 36.5 to 43.4 mg g,1 for copper concentrations between 1 and 60 mg dm,3. Dynamic and batch isotherms showed different shapes but a similar maximum uptake capacity. Sorbent regeneration was successfully performed with HCl. A potential relationship between dispersion coefficient and velocity was obtained with dispersion coefficients between 5.00 × 10,8 and 2.95 × 10,6 m2 s,1 for water velocities ranging between 0.56 × 10,4 and 5.03 × 10,4 m s,1. The mass transport model predicted both the breakpoints and the shape of the breakthrough curves. CONCLUSIONS: High retention capacities indicate that peat can be used as an effective sorbent for the treatment of wastewater containing copper ions. Copyright © 2009 Society of Chemical Industry [source]

Mercury removal: a physicochemical study of metal interaction with natural materials

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2009
Leticia Carro
Abstract BACKGROUND: Mercury is considered one of the most harmful heavy metals to the environment and human health, so recently remediation processes have been developed to eliminate this metal from wastewaters. Metal retention by natural polymers is a good alternative technique to remove heavy metals from solution. RESULTS: A screening of 25 potential mercury sorbents was carried out at three different pH values in order to find appropriate biomass to remove this metal from polluted waters. High sorption capacities were found for many of the materials studied. Four of these materials were selected for further detailed study. Kinetic studies showed short times to reach equilibrium. For S. muticum, sorption isotherms were obtained at several temperatures and a sorption enthalpy value was obtained. Desorption experiments were performed to determine the possibility for recycling of this brown alga. CONCLUSIONS: Different materials have been found to be potentially good adsorbents of mercury. A detailed study showed that S. muticum is an excellent material with a mercury uptake about 200 mg g,1. This brown alga has a fast kinetic process (80% of metal is removed from solution in 30 min), and very high metal uptake over a wide pH range, up to 92% elimination for pH values above 3,4. Copyright © 2009 Society of Chemical Industry [source]

Optimization and analysis of nickel adsorption on microwave irradiated rice husk using response surface methodology (RSM)

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2009
Magesh Ganesa Pillai
Abstract BACKGROUND: The removal of heavy metals using adsorption techniques with low cost biosorbents is being extensively investigated. The improved adsorption is essentially due to the pores present in the adsorbent. One way of improving the porosity of the material is by irradiation of the precursor using microwaves. In the present study, the adsorption characteristics of nickel onto microwave-irradiated rice husks were studied and the process variables were optimized through response surface methodology (RSM). RESULT: The adsorption of nickel onto microwave-irradiated rice husk (MIRH) was found to be better than that of the raw rice husk (RRH). The kinetics of the adsorption of Ni(II) from aqueous solution onto MIRH was found to follow a pseudo-second-order model. Thermodynamic parameters such as standard Gibbs free energy (,G°), standard enthalpy (,H°), and standard entropy (,S°) were also evaluated. The thermodynamics of Ni(II) adsorption onto MIRH indicates that it is spontaneous and endothermic in nature. The response surface methodology (RSM) was employed to optimize the design parameters for the present process. CONCLUSION: Microwave-irradiated rice husk was found to be a suitable adsorbent for the removal of nickel(II) ions from aqueous solutions. The adsorption capacity of the rice husk was found to be 1.17 mg g,1. The optimized parameters for the current process were found as follows: adsorbent loading 2.8 g (100 mL),1; Initial adsorbate concentration 6 mg L,1; adsorption time 210 min.; and adsorption temperature 35 °C. Copyright © 2008 Society of Chemical Industry [source]