bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solid phase microextraction (SPME) applied to honey quality control
Authors: Piasenzotto Lara , Gracco Luisa , Conte Lanfranco 
Published: July 2003

AbstractThe assessment of the botanical origin of unifloral honeys is an important application in food control. The current official methods mainly use pollen analysis. The aim of this paper is to present an SPME analytical approach to the study of honey volatiles. Honey samples (40) obtained from hive sites in different regions of Italy were analysed. The samples had six different botanical origins: citrus (five), chestnut (10), eucalyptus (eight), lime tree (11), thyme (two) and dandelion (four). Melissopalynological analysis was also performed. Identification of volatile compounds was carried out by SPME/GC/MS analysis, and quantitative evaluation was done by SPME/GC/FID analysis for compounds with well‐resolved peaks. Using the SPME method, all samples with the same botanical origin gave remarkably similar GC profiles. Some volatile compounds were found only in specific floral source honey samples and thus could be interesting for use as markers. Copyright © 2003 Society of Chemical Industry
Interactions between polypeptides derived from barley and other beer components in model foam systems
Authors: Bamforth CW , Kanauchi M 
Published: July 2003

AbstractThe impact of a range of variables on the foaming properties of hordein‐ and albumin‐derived fractions from barley has been investigated. When foamed using nitrogen, the hordein‐derived polypeptides produce the most stable foams. However, when carbon dioxide was the foaming agent, the previously reported observations were repeated, namely that proteolysis weakens the foaming capabilities of albumin, whereas partial hydrolysis enhances the stability of foams derived from hordein. At lower levels of bitterness (iso‐α‐acid) addition there is a reduction in foam stability of albumin‐derived polypeptides, although hordein‐derived polypeptides can withstand this destabilising effect. Higher bitterness levels in both instances lead to a stabilisation of foam. It is likely that this involves ionic interactions between the acid anion (pKof iso‐α‐acids is ca 3.1) and divalent cations, because higher pHs (in the range 3.8–4.6) and the addition of zinc lead to an enhancement of foam stability, particularly of the albumin‐derived fractions. The foaming of the latter, however, is significantly impaired by the presence of ethanol, whereas hordein‐based foams are enhanced by increasing concentrations of ethanol. Copyright © 2003 Society of Chemical Industry
Enhanced coloration reveals high antioxidant potential in new sweetpotato cultivars
Authors: Philpott Martin , Gould Kevin S , Markham Kenneth R , Lewthwaite Steve L , Ferguson Lynnette R 
Published: July 2003

AbstractSweetpotato is one of the world's most important food crops, particularly in developing countries. The storage roots have high carbohydrate and vitamin A contents and possess strong antioxidant potential, previously attributed to their hydroxycinnamic acid content. We report on several new purple sweetpotatoes developed for their high anthocyanin content. Although the antioxidant activity of purple sweetpotato extracts was greater than that of sweetpotato lacking anthocyanins, anthocyanins alone could not account for all the activity. Extract components were separated by 2D paper chromatography, and their relative contributions to antioxidant activity were determined. The antioxidant activity of the extracts from sweetpotato was shown to be due to both anthocyanins and hydroxycinnamic acids, additively. Neither the anthocyanin content nor the antioxidant activity of sweetpotato flesh was affected by common cooking methods. These findings may be important in the light of the health‐protective properties attributed to both antioxidants and anthocyanins. Copyright © 2003 Society of Chemical Industry
Rheological/textural properties of starch and crude hsian‐tsao leaf gum mixed systems
Authors: Lai Lih‐Shiuh , Liu Ying‐Ling , Lin Pei‐Hsuan 
Published: July 2003

AbstractThe Effects of hsian‐tsao leaf gum (HG) on the rheological/textural properties of non‐waxy starches were studied. Pronounced interactions between starch and HG were observed. The rheological properties, including pseudo‐gel viscosity in the rapid visco‐analyser test, storage and loss moduli in the dynamic rheological test, as well as firmness in the texture analyser test, of the mixed gels generally improved with increasing gum concentration to a certain level, then deteriorated with further increase in gum concentration. The critical gum concentration for the development of optimal rheological properties depended on the starch type and concentration. Within the concentration range studied, mixed systems with wheat starch could generally reach the highest pseudo‐gel viscosity, firmness, and storage modulus if the starch/HG ratio was appropriate, followed by those with corn and tapioca starch. Copyright © 2003 Society of Chemical Industry
Effects of moist heat treatment on ruminal nutrient degradability of sunflower seed
Authors: Mustafa Arif F , Chouinard Yvan P , Ouellet Daniel R , Soita Henry 
Published: July 2003

AbstractA study was conducted to determine the effects of moist heat treatment (autoclaving at 127 °C with a steam pressure of 117 kPa for 10, 20 and 30 min) of sunflower seed on crude protein (CP) fractions, ruminal dry matter (DM) and CP degradabilities, and ruminal disappearance of amino and fatty acids. Two ruminally fistulated cows were used in a randomised complete block design. Heating of sunflower seed decreased soluble protein and increased neutral detergent‐insoluble protein, with little effect on acid detergent‐insoluble protein. Results of the in sacco study showed that moist heat treatment decreased (cubic effect, P < 0.05) ruminal degradability of DM and CP of sunflower seed. Ruminal undegraded CP of raw sunflower seed was low (84 g kg−1 of CP) and increased (cubic effect, P < 0.05) by 139, 143 and 164% as the heating time increased from 0 to 10, 20 and 30 min respectively. Ruminal disappearance of all amino acids (following 12 h of incubation) was greater (P < 0.05) for raw than for heated sunflower seed. Similar results were also observed for ruminal disappearance of fatty acids. It was concluded that moist heat treatment decreased ruminal DM and CP degradability of sunflower seed (by 17 and 19% respectively) and thus increased the concentrations of amino acids and polyunsaturated fatty acids available for digestion in the small intestine. Copyright © 2003 Society of Chemical Industry
The effect of edible coatings and polymeric packaging films on the quality of minimally processed carrots
Authors: Emmambux Naushad M , Minnaar Amanda 
Published: July 2003

AbstractMinimally processed carrots have a short shelf‐life because of white blush formation (caused primarily by surface dehydration) and microbiological spoilage (caused mostly by lactic acid bacteria). The use of polymeric packaging films combined with edible coatings might have an additive or synergistic effect to extend the shelf‐life of minimally processed carrots because of the formation of a double barrier to gases and water vapour. A 3 × 3 factorial experiment using a polymeric packaging film of three different levels of permeability and a cellulose‐based edible coating (Nature Seal®) at different concentrations was conducted on minimally processed carrots to investigate any possible synergistic effect over 12 days of storage at 10 °C. No such effect was found. The polymeric packaging film effectively prevented microbiological growth and spoilage but was unable to control white blush formation. On the other hand, the edible coating partially controlled white blush formation but enhanced microbiological spoilage. The polymeric packaging film functioned primarily as a gas barrier, whereas the edible coating probably functioned as a moisture barrier. White blush formation was found to be the most important shelf‐life determinant for minimally processed carrots. Copyright © 2003 Society of Chemical Industry
Fatty acids, sterols and other steroids from seeds of Patagonian Prosopis species
Authors: Mazzuca Marcia , Balzaretti Vilma T 
Published: July 2003

AbstractSeeds of Prosopis alpataco, P denudans var denudans, P denudans var patagonica and P denudans var stenocarpa were analysed for fatty acids and sterols. The seed lipids contained a relatively large proportion of unsaturated fatty acids, with linoleic and oleic acids being predominant. β‐Sitosterol was the major steroid in all species studied. In P alpataco seeds, stigmasta‐1,3,5‐triene and stigmasta‐4,6‐dien‐3‐one were also identified. Copyright © 2003 Society of Chemical Industry
Oral copper loading test in humans
Authors: Rahmaniyan Mojgan , Johnston Kelley E. , Tamura Tsunenobu 
Published: July 2003

AbstractThere has been no report of normal responses of plasma copper and/or ceruloplasmin concentrations after an oral loading dose of unlabeled copper in humans. To establish a normal plasma response curve following an oral dose, we performed a copper‐loading test (10 mg elemental copper as copper sulfate) in six healthy adult subjects and monitored plasma copper and ceruloplasmin concentrations for 3.5 h. We found that there were no significant changes in plasma copper and ceruloplasmin concentrations following the oral dose in the subjects. The test was originally intended to evaluate whether there was copper malabsorption in a female patient who developed signs of copper deficiency with her plasma copper levels below 3.0 μmol/l after multiple gastrointestinal surgeries. She did not respond to oral copper sulfate administration but responded to a sublingual application of copper glycinate. These findings suggest that she does not have adequate intestinal copper absorption. In conclusion, the use of unlabeled copper, such as copper sulfate, for an oral loading test, seemingly simple and economical, does not appear to be a suitable means to evaluate copper absorption in humans and is discouraged. In case of copper malabsorption, sublingual administration of copper may be worth trying. J. Trace Elem. Exp. Med. 16: 61–66, 2003. © 2003 Wiley‐Liss, Inc.
Changes of zinc, copper, and iron levels in the lung of male rats after subacute (4‐week) and subchronic (13‐week) exposure to formaldehyde
Authors: Özen Og̊uz Aslan , Songur Ahmet , Sarsılmaz Mustafa , Yaman Mehmet , Kuş İlter 
Published: July 2003

AbstractThe medical use of formaldehyde has focused especially on laboratory use. Harmful effects of formaldehyde inhalation, such as nasal squamous cell carcinoma, are quite well documented. However, detailed studies of the mechanisms of the damaging effects of formaldehyde on lung tissue are quite limited. Amounts of such elements as zinc, copper, and iron within lung tissue indicate whether or not they function physiologically. In this study, 36 adult albino Wistar male rats (6 animals per group) were exposed to 0 (Control), 5, and 10 ppm (1 ppm ≊ 1.2 mg/m3) of formaldehyde gas for subacute (4‐week) and subchronic (13‐week) periods. Whole‐body exposure was continuously carried out for 8 h/day, 5 days/week. Body weights were recorded weekly. Levels of metals mentioned above were measured in lung tissue by atomic absorption spectrometry using wet ashing and were then compared with levels in the control groups. At the end of the study, a gradual decrease in weight gain, a decrease in zinc levels, and an increase in iron levels were observed in both subacute and subchronic groups compared to control groups. Statistically significant increases in tissue Fe levels were seen in the 10 ppm subacute (P < 0.001), 5 ppm subchronic (P < 0.001), and 10 ppm subchronic (P < 0.001) groups. We conclude that subacute or subchronic exposure to cytotoxic concentrations of formaldehyde may cause growth retardation and alter the trace element levels of zinc and iron in the lung tissue. J. Trace Elem. Exp. Med. 16:67–74, 2003. © 2003 Wiley‐Liss, Inc.
Effects of three divalent cations: manganese, zinc, and magnesium on arterial blood pressures in guinea pigs
Authors: Onat Nursen , Süzer Öner 
Published: July 2003

AbstractOur aim was to compare the effects of the divalent cations, namely magnesium, zinc, and manganese on the arterial blood pressures and heart rate of guinea pigs. Eighteen guinea pigs weighing 500–700 g were divided into three groups (six in each group), and three divalent cations as sulfate salt (MgSO4, ZnSO4, MnSO4) were administered to all animals after 20‐min period of stabilization and at three escalating concentrations (10−6, 10−5, 10−4 mol/kg intravenously, respectively) in 25‐min intervals. Each animal received only one kind of cation. Arterial pressures and heart rate were measured and their derivatives were calculated (dp/dt). Our study showed that divalent cations lowered the arterial blood pressures. No significant differences were between groups for systolic, diastolic, and mean pressures, except that 10−4 mol/kg ZnSO4 was lethal. The heart rates values of ZnSO4 (202 ± 9) was significantly (P < 0.05) lower after 10−6 mol/kg than MgSO4 (230 ± 7). Three divalent cations caused to decrease on arterial pressures. Zn2+ caused cardiac arrest in the highest dose. Intravenous administration of Mn2+ and Mg2+ seems to have similar effects on arterial blood pressures and heart rate. Further work is needed to relate effects on Mn2+ for their possible use in the emergency department. J. Trace Elem. Exp. Med. 16:75–85, 2003. © 2003 Wiley‐Liss, Inc.
Effects of vitamin E and selenium on thyroid status, adrenocorticotropin hormone, and blood serum metabolite and mineral concentrations of Japanese quails reared under heat stress (34°C)
Authors: Ferit Gursu M. , Sahin N. , Kucuk O. 
Published: July 2003

AbstractThis study was conducted to determine the effects of vitamin E and selenium (Se) on triiodothyronine (T3), thyroxine (T4), thyroid stimulating hormone (TSH), adrenocorticotropin hormone (ACTH), and serum glucose, urea, triglyceride, cholesterol, Ca, P, Na, and K concentrations of Japanese quails reared under heat stress (34°C). One‐hundred twenty 10‐day‐old Japanese quails were randomly assigned to four treatment groups with three replicates of 10 birds each. The birds with a 2 × 2 factorial design received either two levels of vitamin E (125 and 250 mg/kg of diet) or two levels of selenium (0.1 and 0.2 mg/kg of diet). Greater dietary vitamin E and selenium inclusions resulted in a greater (P = 0.001) serum T3, T4, and TSH, but lower (P = 0.001) ACTH concentrations. No interactions between vitamin E and selenium were detected (P ≥ 0.11) for serum concentrations of T3, T4, TSH, and ACTH. Serum glucose, urea, triglyceride, and cholesterol concentrations decreased (P = 0.001), whereas protein concentrations increased (P = 0.001) when both dietary vitamin E and selenium increased. Serum albumin concentrations increased (P = 0.001) with greater dietary vitamin E but did not change with dietary selenium (P = 0.16). No interactions on any blood metabolites were detected (P ≥ 0.11). Serum activities of serum glutamic oxalate transaminase and serum glutamic pyruvate transaminase were not influenced by dietary vitamin E or selenium (P ≥ 0.42). However, serum activity of alkaline phosphatase increased (P = 0.001) with both increasing dietary vitamin E and selenium. There were no interactions detected for the serum enzyme activities (P ≥ 0.09). Increasing both dietary vitamin E and selenium caused an increase in serum concentrations of Ca, P, and K (P = 0.001), but a decrease in serum concentrations of Na (P = 0.001). No interactions were detected for serum mineral concentrations (P ≥ 0.07) except for P (P = 0.001). Results of the present study showed that dietary vitamin E and selenium have synergistic effects, and that supplementing a combination of dietary vitamin E (250 mg) and selenium (0.2 mg) positively influences some blood parameters that may positively influence the performance of Japanese quails under heat stress. J. Trace Elem. Exp. Med. 16:95–104, 2003. © 2003 Wiley‐Liss, Inc.
Association between oxidative stress and selenium levels in patients with breast cancer at different clinical stages
Authors: Sancak Banu , Ünal Adem , Candan Sakine , Coşkun Uḡur , Günel Nazan 
Published: July 2003

AbstractOxidative stress has been suggested to play a role in some physiological conditions and in many disease processes, including carcinogenesis. The aim of the study was to investigate the association between the oxidative stress and selenium levels in the erythrocytes of breast cancer patients at different clinical stages. The extent of lipid peroxidation was assessed by measuring thiobarbituric acid reactive substances (TBARS), called malondialdehyde (MDA), in erythrocytes. Glutathione peroxidase activity (GPx) in erythrocyte and serum selenium levels were determined in patients and controls. Thirty‐three female breast cancer patients at different clinical stages were divided into four groups. Ten control subjects were also included in this study. Atomic absorption, spectrophotometry, and colorimetric methods were used to obtain serum selenium and erythrocyte MDA levels, respectively. GPx activities were assessed with kinetic method described by Paglia and Valentine (J Lab Clin Med 1967; 70(1):158–169). All cancer patients (groups A, B, and C) showed significant increases in erythrocyte GPx activities compared with those in control subjects (P < 0.05). No significant differences were found among the cancer patients at different clinical stages (P > 0.05). Although plasma selenium levels did not change among the groups A, B, and C, it was demonstrated that breast cancer patients have lower serum selenium levels than healthy controls (P < 0.05). Significantly increased lipid peroxidation, measured as erythrocyte MDA, was demonstrated in patients with breast cancer compared to the control group (P < 0.05). There were no differences between group A and group B in terms of MDA levels (P > 0.05). Erythrocyte MDA levels were significantly lower (P < 0.05) in breast cancer patients who had had surgery within 1 month (group A) when compared with those levels in breast cancer patients who had just been diagnosed and had not had any surgery yet (group C). Although clinical stage in breast cancer does not have any effect on serum selenium levels or erythrocyte GPx activity, erythrocyte MDA levels changed among the patients at different clinical stages. Increased MDA levels in untreated patients show us increased oxidative stress. If we removed malignant breast tissue by surgery and gave adjuvant therapy, lipid peroxidation product MDA levels in erythrocyte would decrease. Increased GPx enzyme activity in erythrocytes may be a result of a protective mechanism that develops in breast cancer patients against free radical damage. Although an inverse correlation between the serum selenium levels and erythrocyte GPx activity in patients with breast cancer is suggested, there is no correlation at different clinical stages of patients. J Trace Elem. Exp. Med. 16:87–94, 2003. © 2003 Wiley‐Liss, Inc.
Copper retention in intestinal mucosal cells of young men at normal and high copper intakes
Authors: Turnlund Judith R. , Domek Joseph M. , Nair Padmanabhan P. , Bhathena Sam J. 
Published: July 2003

AbstractThe role of intestinal cells in copper homeostasis and storage has not been studied. Homeostasis is regulated by absorption, excretion, and storage. Copper is excreted via the bile, and it has been assumed that the increased excretion into the gastrointestinal tract when diets are high in copper was due to biliary copper. It seemed possible that some of the absorbed copper is sequestered in the intestinal cells. To test this hypothesis we measured the copper content of mucosal epithelial cells isolated from stool samples of 8 young men when consuming their usual diets and after 129 days of supplementation with 7 mg/day copper. The mean copper content of the cells, expressed as mg copper per gram of cell protein, was 0.78 versus 1.65 mg/g (SEM 0.19) (P < 0.02) when the usual and copper‐supplemented diets, respectively, were consumed. In contrast to the copper content of plasma and urine, copper in intestinal cells increased significantly when intake was high. It is likely that copper was sequestered by these cells following absorption and did not get into systemic circulation. Thus, the amount of endogenous copper in stools is probably a combination of biliary copper excretion and copper sequestered in exfoliated intestinal epithelial cells. This suggests that retention of copper by the intestinal cells increases when dietary copper is high and plays a role in copper homeostasis. J. Trace Elem. Exp. Med. 16:105–108, 2003. Published 2003 Wiley–Liss, Inc.
The use of electrochemical techniques for the investigation and monitoring of microbiologically influenced corrosion and its inhibition – a review
Authors: Mansfeld F. 
Published: July 2003

AbstractThe background of several electrochemical techniques – recording of the corrosion potential Ecorr, electrochemical impedance spectroscopy (EIS), electrochemical noise analysis (ENA) and recording of potentiodynamic polarization curves – has been discussed and examples of the use of these techniques in studies of microbiologically influenced corrosion (MIC) and MIC inhibition have been presented. These examples range from the use of the polarization resistance Rp and the noise resistance Rn in corrosion monitoring in a sewer environment and a gas production field, respectively, to the application of EIS and ENA in the evaluation of the interaction of bacteria with protective coatings on steel exposed to natural seawater (NS). A more detailed analysis based on EIS and ENA of Corrosion protection of Al 2024, mild steel and brass in artificial seawater (AS) by bacteria such as B. subtilis, B. licheniformis, E. coli and Shewanella has been presented. Determination of the changes of Rp and Rn as well as Ecorr allows to propose appropriate mechanisms of MIC inhibition. These mechanisms have been confirmed in the case of S. algae by recording of anodic and cathodic potentiodynamic polarization curves after exposure to AS containing the bacteria for extended time periods.
Microbiologically influenced corrosion of stainless steels – What is required for pitting?
Authors: Hakkarainen T. J. 
Published: July 2003

AbstractPitting of stainless steels in environments normally regarded as completely harmless is often attributed to microbial activity. In this paper, attention is drawn on one hand to the basic requirements for pitting of stainless steels to be possible, and on the other hand to various ways how microbial activity could contribute to a fulfilment of these requirements. For pit growth to be possible, three basic requirements must be fulfilled: 1) the environment must contain anions that can form an aggressive solution into the pit, 2) there must be a potential difference between the interior of the pit and the open surface outside the pit, 3) the temperature must exceed a critical value. The main factors that normally influence the possibility of pitting are the chloride content and the oxidising power of the environment, presence of anions other than chloride, temperature, possible presence of deposits on the steel surface, and the composition of the steel. Anions other than chloride in the bulk solution, including sulphate, usually have an inhibiting effect. Thiosulphate, however, is known to promote pitting under certain conditions. The possible ways of microbial activity to enhance pitting could include deposit formation leading to crevice type of attack, local modification of the composition of the environment to a more concentrated one, raising the electrode potential of the steel surface (“ennoblement”), or formation of reaction products that permit active dissolution inside a pit at lower potentials. Special attention is drawn to the possible action of thiosulphate by enhancing the anodic reaction at low potentials of the dissolving surface inside the pits.