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Publisher: Springer-Verlag   (Total: 2210 journals)

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Dysphagia     Hybrid Journal   (Followers: 192, SJR: 0.684, h-index: 46)
e & i Elektrotechnik und Informationstechnik     Hybrid Journal   (Followers: 8, SJR: 0.146, h-index: 8)
e-Neuroforum     Hybrid Journal  
Early Childhood Education J.     Hybrid Journal   (Followers: 12, SJR: 0.367, h-index: 12)
Earth Science Informatics     Hybrid Journal   (Followers: 3, SJR: 0.245, h-index: 5)
Earth, Moon, and Planets     Hybrid Journal   (Followers: 5, SJR: 0.436, h-index: 28)
Earthquake Engineering and Engineering Vibration     Hybrid Journal   (Followers: 7, SJR: 0.433, h-index: 17)
Earthquake Science     Hybrid Journal   (Followers: 9, SJR: 0.486, h-index: 7)
East Asia     Hybrid Journal   (Followers: 7, SJR: 0.165, h-index: 9)
Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity     Hybrid Journal   (Followers: 7, SJR: 0.289, h-index: 23)
EcoHealth     Hybrid Journal   (Followers: 1, SJR: 0.651, h-index: 22)
Ecological Research     Hybrid Journal   (Followers: 8, SJR: 0.698, h-index: 38)
Economic Botany     Hybrid Journal   (Followers: 8, SJR: 0.666, h-index: 40)
Economic Bulletin     Hybrid Journal   (Followers: 4)
Economic Change and Restructuring     Hybrid Journal   (Followers: 1, SJR: 0.263, h-index: 6)
Economic Theory     Hybrid Journal   (Followers: 7, SJR: 1.857, h-index: 31)
Economic Theory Bulletin     Hybrid Journal   (Followers: 1)
Economics of Governance     Hybrid Journal   (Followers: 2, SJR: 0.367, h-index: 12)
Ecosystems     Hybrid Journal   (Followers: 19, SJR: 1.793, h-index: 83)
Ecotoxicology     Hybrid Journal   (Followers: 10, SJR: 1.041, h-index: 53)
Education and Information Technologies     Hybrid Journal   (Followers: 171, SJR: 0.207, h-index: 15)
Educational Assessment, Evaluation and Accountability     Hybrid Journal   (Followers: 14, SJR: 0.519, h-index: 14)
Educational Psychology Review     Hybrid Journal   (Followers: 14, SJR: 1.781, h-index: 52)
Educational Research for Policy and Practice     Hybrid Journal   (Followers: 6, SJR: 0.211, h-index: 8)
Educational Studies in Mathematics     Hybrid Journal   (Followers: 9, SJR: 0.946, h-index: 27)
Educational Technology Research and Development     Partially Free   (Followers: 181, SJR: 1.124, h-index: 45)
Electrical Engineering     Hybrid Journal   (Followers: 12, SJR: 0.352, h-index: 17)
Electrocatalysis     Hybrid Journal   (SJR: 0.542, h-index: 7)
Electronic Commerce Research     Hybrid Journal   (Followers: 2, SJR: 0.636, h-index: 14)
Electronic Markets     Hybrid Journal   (Followers: 6, SJR: 0.326, h-index: 5)
Electronic Materials Letters     Hybrid Journal   (Followers: 3, SJR: 0.566, h-index: 11)
Elemente der Mathematik     Hybrid Journal  
Emergency Radiology     Hybrid Journal   (Followers: 4, SJR: 0.446, h-index: 22)
Empirica     Hybrid Journal   (Followers: 3, SJR: 0.185, h-index: 12)
Empirical Economics     Hybrid Journal   (Followers: 8, SJR: 0.5, h-index: 29)
Empirical Software Engineering     Hybrid Journal   (Followers: 4, SJR: 2.319, h-index: 33)
Employee Responsibilities and Rights J.     Hybrid Journal   (Followers: 2, SJR: 0.21, h-index: 13)
Endocrine     Hybrid Journal   (Followers: 5, SJR: 0.659, h-index: 55)
Endocrine Pathology     Hybrid Journal   (Followers: 2, SJR: 0.555, h-index: 27)
Energy Efficiency     Hybrid Journal   (Followers: 11, SJR: 1.056, h-index: 10)
Energy Systems     Hybrid Journal   (Followers: 10, SJR: 0.589, h-index: 5)
Engineering With Computers     Hybrid Journal   (Followers: 5, SJR: 0.497, h-index: 26)
Entomological Review     Hybrid Journal   (Followers: 3, SJR: 0.128, h-index: 5)
Environment Systems & Decisions     Hybrid Journal   (Followers: 2)
Environment, Development and Sustainability     Hybrid Journal   (Followers: 28, SJR: 0.319, h-index: 26)
Environmental and Ecological Statistics     Hybrid Journal   (Followers: 5, SJR: 0.389, h-index: 29)
Environmental and Resource Economics     Hybrid Journal   (Followers: 17, SJR: 1.651, h-index: 46)
Environmental Biology of Fishes     Hybrid Journal   (Followers: 4, SJR: 0.486, h-index: 53)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 3, SJR: 0.664, h-index: 22)
Environmental Earth Sciences     Hybrid Journal   (Followers: 10, SJR: 0.601, h-index: 55)
Environmental Economics and Policy Studies     Hybrid Journal   (Followers: 6, SJR: 0.35, h-index: 3)
Environmental Evidence     Open Access  
Environmental Fluid Mechanics     Hybrid Journal   (Followers: 2, SJR: 0.732, h-index: 23)
Environmental Geochemistry and Health     Hybrid Journal   (Followers: 2, SJR: 0.909, h-index: 32)
Environmental Geology     Hybrid Journal   (Followers: 11)
Environmental Health and Preventive Medicine     Hybrid Journal   (Followers: 2, SJR: 0.388, h-index: 14)
Environmental Management     Hybrid Journal   (Followers: 32, SJR: 0.773, h-index: 60)
Environmental Modeling & Assessment     Hybrid Journal   (Followers: 11, SJR: 0.413, h-index: 27)
Environmental Monitoring and Assessment     Hybrid Journal   (Followers: 9, SJR: 0.671, h-index: 46)
Environmental Science and Pollution Research     Hybrid Journal   (Followers: 11, SJR: 0.878, h-index: 42)
Epidemiologic Perspectives & Innovations     Open Access   (Followers: 1, SJR: 1.002, h-index: 14)
Epileptic Disorders     Hybrid Journal   (Followers: 1, SJR: 0.669, h-index: 34)
EPJ A - Hadrons and Nuclei     Hybrid Journal   (Followers: 1, SJR: 1.435, h-index: 58)
EPJ B - Condensed Matter and Complex Systems     Hybrid Journal   (Followers: 3, SJR: 0.749, h-index: 85)
EPJ direct     Hybrid Journal  
EPJ E - Soft Matter and Biological Physics     Hybrid Journal   (Followers: 1, SJR: 0.661, h-index: 57)
EPMA J.     Open Access   (SJR: 0.161, h-index: 4)
ERA-Forum     Hybrid Journal   (Followers: 2, SJR: 0.13, h-index: 2)
Erkenntnis     Hybrid Journal   (Followers: 11, SJR: 0.62, h-index: 14)
Erwerbs-Obstbau     Hybrid Journal   (SJR: 0.173, h-index: 8)
Esophagus     Hybrid Journal   (SJR: 0.268, h-index: 9)
Estuaries and Coasts     Hybrid Journal   (Followers: 3, SJR: 1.111, h-index: 61)
Ethical Theory and Moral Practice     Hybrid Journal   (Followers: 7, SJR: 0.278, h-index: 8)
Ethics and Information Technology     Hybrid Journal   (Followers: 182, SJR: 0.363, h-index: 20)
Ethik in der Medizin     Hybrid Journal   (SJR: 0.204, h-index: 6)
Euphytica     Hybrid Journal   (Followers: 7, SJR: 0.709, h-index: 57)
Eurasian Soil Science     Hybrid Journal   (Followers: 2, SJR: 0.271, h-index: 10)
EURO J. of Transportation and Logistics     Hybrid Journal   (Followers: 4)
EURO J. on Computational Optimization     Hybrid Journal  
EURO J. on Decision Processes     Hybrid Journal  
Europaisches J. fur Minderheitenfragen     Hybrid Journal  
European Actuarial J.     Hybrid Journal   (Followers: 3)
European Archives of Oto-Rhino-Laryngology     Hybrid Journal   (Followers: 4, SJR: 0.737, h-index: 37)
European Archives of Paediatric Dentistry     Hybrid Journal   (Followers: 1, SJR: 0.446, h-index: 12)
European Archives of Psychiatry and Clinical Neuroscience     Hybrid Journal   (Followers: 2, SJR: 1.334, h-index: 62)
European Biophysics J.     Hybrid Journal   (Followers: 4, SJR: 0.979, h-index: 53)
European Child & Adolescent Psychiatry     Hybrid Journal   (Followers: 4, SJR: 1.269, h-index: 51)
European Clinics in Obstetrics and Gynaecology     Hybrid Journal   (Followers: 5)
European Food Research and Technology     Hybrid Journal   (Followers: 8, SJR: 0.773, h-index: 49)
European J. for Education Law and Policy     Hybrid Journal   (Followers: 5)
European J. for Philosophy of Science     Partially Free   (Followers: 4, SJR: 0.165, h-index: 2)
European J. of Ageing     Hybrid Journal   (Followers: 9, SJR: 0.49, h-index: 17)
European J. of Applied Physiology     Hybrid Journal   (Followers: 8, SJR: 1.044, h-index: 74)
European J. of Clinical Microbiology & Infectious Diseases     Hybrid Journal   (Followers: 11, SJR: 0.958, h-index: 74)
European J. of Clinical Pharmacology     Hybrid Journal   (Followers: 9, SJR: 0.916, h-index: 69)
European J. of Dermatology     Hybrid Journal   (Followers: 7)
European J. of Drug Metabolism and Pharmacokinetics     Hybrid Journal   (Followers: 6, SJR: 0.24, h-index: 25)
European J. of Epidemiology     Hybrid Journal   (Followers: 17, SJR: 1.946, h-index: 60)
European J. of Forest Research     Hybrid Journal   (Followers: 3, SJR: 0.864, h-index: 25)
European J. of Health Economics     Hybrid Journal   (Followers: 11, SJR: 0.67, h-index: 25)

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Journal Cover European Food Research and Technology
   [10 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1438-2377 - ISSN (Online) 1438-2385
     Published by Springer-Verlag Homepage  [2210 journals]   [SJR: 0.773]   [H-I: 49]
  • Migration of phenolic compounds from different cork stoppers to wine model
           solutions: antioxidant and biological relevance
    • Abstract: Abstract Considering the enological interest of cork, this study aimed to identify and quantify the phenolic compounds able to migrate from different classes (natural cork stoppers “Flor” and “Third” quality and microagglomerate cork stopper) of cork stoppers into bottled wine model solutions. Another aim was to evaluate some antioxidant and biological features of cork phenolics that migrated into the wine model solutions. The main phenolic acids and aldehydes detected were as follows: gallic and protocatechuic acid detected both around 3.5 mg/L and vanillin and protocatechuic aldehyde detected around 2.5 and 1.5 mg/L after 27 months of bottling, respectively. Trace amounts of more complex polyphenols, namely hydrolysable tannins (castalagin/vescalagin and mongolicain A/B), were also detected. Two antioxidant features of the wine model solutions bottled with different wine cork stoppers were studied, namely the antiradical capacity and the reducing capacity, being the natural cork stoppers the ones with the higher activities. The intestinal absorption of the compounds in each wine model solution after 27 months in bottled was evaluated. The simpler phenolic compounds were able to cross Caco-2 cell model. The antiproliferative activity of the same wine model solutions was also evaluated against gastric and breast cancer cells. All samples were active against the two cell lines, which highlight the possible health outcomes of wine sealed with cork stoppers.
      PubDate: 2014-12-01
       
  • Microencapsulation of capsanthin by self-emulsifying nanoemulsions and
           stability evaluation
    • Abstract: Abstract The application of natural colorants in food products has been gained more and more attention, not only due to their nutritional advantages, but also their functional properties. The purpose of this research was to encapsulate capsanthin from paprika by nanoemulsions (NEs), and the stability of resultant NEs was evaluated. The NE systems were first optimized by dropwise adding mixed organic phase [5 wt% medium-chain triglyceride (MCT) and 10 wt% surfactant containing span 20 and tween 80 with the weight ratio 1:3 and HLB 13.4] into water phase. Then capsanthin was mixed with MCT as the oil phase. With the presence of capsanthin, the oil phase composition had great impact on the particle size of NEs that the droplet size increased from 30 to 150 nm with increasing capsanthin content. Generally, higher temperature and stirring speed would decrease the particle size, which also depended on the surfactant-to-oil ratio. The stability results demonstrated that there was no obvious change on the capsanthin NE droplet size and entrapped capsanthin content after 1 month storage at ambient temperature. Our results are important for the design of food-grade delivery systems to encapsulate natural lipophilic pigments or ingredients.
      PubDate: 2014-12-01
       
  • Purification and characterization of β -glucosidase from Oenococcus
           oeni 31MBR
    • Abstract: Abstract This study was designed to characterize a β-glucosidase from Oenococcus oeni 31MBR, a strain widely used in Chinese winemaking. An intracellular β-glucosidase (EC 3.2.1.21) was partially purified using a combination of ammonium sulfate precipitation and chromatographic methods. A single band was obtained in SDS-PAGE electrophoresis, indicating that the enzyme was highly purified and had an estimated molecular mass of 38.9 kDa. The enzyme exhibited highest activity at pH 4.5–5.0. The optimum temperature was 45 °C. Ethanol promoted the activity of this enzyme up to three times. Among the several metal ions assayed, only Mn2+ exhibited a partial promotion effect. The K m and V max values for p-nitrophenyl-β-d-glucopyranoside were 1.05 mmol/L and 0.957 nmol/min, respectively. Up to now, this study contains the first characterization of a native β-glucosidase purified from crude extracts of O. oeni 31MBR.
      PubDate: 2014-12-01
       
  • Isolation of angiotensin I-converting enzyme inhibitor from pepsin
           hydrolysate of porcine hemoglobin
    • Abstract: Abstract Angiotensin I-converting enzyme (ACE) inhibitors have been widely used as antihypertensive agents. However, most synthetic ACE inhibitors ineluctably have severe side effects. Researchers have focused on various ACE-inhibitory peptides derived from dietary food. In the present study, we reported peptides produced from porcine blood, an important food in Asian countries. Through enzymatic hydrolysis, we found that peptides from this animal compound have ACE-inhibitory effects. Porcine hemoglobin was hydrolyzed using ordinary proteases, including alcalase, trypsin, neutral, papain, protamex, and pepsin. Results showed that pepsin was the most efficient protease in producing active peptides, and the pepsin hydrolysate of porcine hemoglobin showed the highest activity (IC50 = 1.53 ± 0.03 mg/mL). Combining DA 201-C macroporous resin chromatography, Sephadex LH-20 gel chromatography, and reversed-phase high-performance liquid chromatography, the fraction 2-IV was purified from pepsin hydrolysis of porcine hemoglobin; this compound exhibited the highest ACE-inhibitory activity (IC50 = 0.02 ± 0.01 mg/mL). Through Edman degradation, we also found that the exact amino acid sequence of fraction 2-IV was Gln–Glu–Leu–Pro–Gly. The results indicated that porcine hemoglobin peptides possessed significant ACE-inhibitory effect in vitro, which is an important complement of the previous work.
      PubDate: 2014-12-01
       
  • Superoxide dismutase from hen’s egg yolk can protect fatty acids
           from peroxidative damage
    • Abstract: Abstract Superoxide dismutase (SOD, EC1.15.1.1) is a family of enzymes, which remove superoxide anion (O 2 ·− ) from the cells of living organisms. The aim of this study was to describe antioxidative properties of SOD with regard to the protection of unsaturated fatty acids (UFA) from peroxidative damage and to compare this effect with butylated hydroxytoluene (BHT). In this experiment, Cu, Zn-SOD from hen’s egg yolk with a mass of 15.59 ± 0.38 kDa and pI 6.58 ± 0.10, 6.41 ± 0.08 and 6.30 ± 0.15 was used to protect fatty acids from peroxidative damage in vegetable oil (sunflower oil and olive oil) during 200 days of storage at different temperatures—4, 20 and 35 °C. Antioxidative properties of SOD and BHT were expressed as the ratio of unsaturated to saturated fatty acids (SFA) in samples after 50, 100 and 200 days of storage as well as the percentage content of selected fatty acids in the examined oils. SOD from egg yolk showed the same or better antioxidant properties with regard to the concentration of linoleic acid (C18:2) contained in sunflower oil and olive oil than the corresponding concentrations of BHT during 200-day storage at 4, 20 and 35 °C. The concentration of linoleic acid (C18:2) in the sample with SOD was significantly higher during storage at 35 °C on day 200. At all storage temperatures, the ratio of SFA to UFA in samples with the addition of SOD was statistically higher than in oils stored without the antioxidant. With regard to linoleic acid (C18:2), SOD proved to be a better antioxidant than BHT. The results demonstrated better antioxidant properties of SOD from hen’s eggs compared with the same concentrations of BHT at elevated temperatures (at 20 and 35 °C) in oil with a high content of UFA. No negative antioxidative effect (worse than that of BHT at a corresponding concentration) of the addition of SOD from egg yolk on fatty acid composition of the tested samples was observed. Though further research is necessary, SOD from hen’s egg yolk seems to be a promising natural antioxidant of vegetable oils.
      PubDate: 2014-12-01
       
  • Immobilized alcalase alkaline protease on the magnetic chitosan
           nanoparticles used for soy protein isolate hydrolysis
    • Abstract: Abstract An efficient immobilization of Alcalase 2.4L alkaline protease has been developed by using chitosan-coated magnetic nanoparticles as support via glutaraldehyde cross-linking reaction. The Fe3O4 nanoparticles, Fe3O4-chitosan, and immobilized Alcalase 2.4L alkaline protease were characterized by X-ray diffraction, transmission electron microscope, Fourier transform infrared spectroscopy, electron spin resonance, and vibrating sample magnetometry. Results showed that the binding of chitosan and Alcalase 2.4L alkaline protease on Fe3O4 through cross-linking was successful. In addition, the Alcalase 2.4L alkaline protease immobilized with chitosan-coated magnetic nanoparticles enhanced the activity, the optimum reaction temperature and pH value for the immobilized enzyme were 55 °C and 10, respectively, compared with the free enzyme, and the optimal temperature and pH profile range were considerably broadened. Similarly, the thermal stability was enhanced by immobilization, and the kinetic parameters of free and immobilized Alcalase 2.4L alkaline protease were determined. Then, from our hydrolysis experiments, we found that immobilized Alcalase 2.4L alkaline protease uses Fe3O4-chitosan had a greatest hydrolytic activity, and the DH of soy protein isolate (SPI) can reach to 18.38 %, against 17.50 % with the free enzyme after 140 min. Furthermore, the immobilized Alcalase 2.4L alkaline protease could maintain about 86 % of its original activity after ten consecutive operations. Thus, Fe3O4-chitosan immobilized Alcalase 2.4L alkaline protease a good candidate for the continuous hydrolysis of SPI.
      PubDate: 2014-12-01
       
  • Fatty acid composition and CLA content in goat milk and cheese samples
           from Umbrian market
    • Abstract: Abstract Goat dairy products are considered as a suitable alternative to cow milk products for some special categories of consumers (infants, old, and convalescent people). In the present research, a study on the lipid fraction of commercial goat milk and cheese samples purchased from Umbrian market was carried out. Particular attention has been paid to evaluating conjugated linoleic acid (CLA) content and determining some interesting nutritional indexes. The results of goat milk samples showed that saturated, monounsaturated and polyunsaturated fatty acid contents were on average 71.2, 23.4, and 3.8 %, respectively. CLA content (cis-9, trans-11 isomer) was on average 11.5 mg/100 g in milk. Considerable variability was observed for n6/n3 ratio that varied from 2.7 to 10.6 in the considered goat milk samples. With regard to goat cheese samples CLA concentration was on average 118.8 mg/100 g in fresh cheese and 217.7 mg/100 g in semi-hard cheese, and the difference was not significant. Interestingly, α-linolenic acid content was higher and n6/n3 ratio was lower in semi-hard with respect to fresh cheese samples (p < 0.05).
      PubDate: 2014-12-01
       
  • Effects of additional fibrils on structural and rheological properties of
           rice bran albumin solution and gel
    • Abstract: Abstract The effects of additional heat-induced fibrils on the viscosity and gel strength of rice bran albumin (RBA) were studied. The structure and morphology of the fibrils were strongly affected by extent of heating time. The mean contour length and particle size of RBA fibrils increased with increasing heating time. The conversion of RBA monomers into linear aggregations at pH 2.0 and 90 °C increased with increasing heating time and protein concentration. Adding mature fibrils to RBA solutions can modify the structural properties and make this system rather complex. Rheological results showed that adding fibrils could promote solution thickening and gel hardening behavior and result in a significant increase in solution viscosity and gel strength. Interestingly, adding the longer heating time fibrils exhibited a higher viscosity values and elastic modulus. Significant difference in gel structure obtained by scanning electron microscopy between fibrils/RBA and RBA was observed. The former has more loose mesh structure than the latter. These results would be of great importance for understanding the physicochemical properties of RBA fibril assembly.
      PubDate: 2014-12-01
       
  • Roasting process affects the profile of diterpenes in coffee
    • Abstract: Abstract There is no consensus in the literature regarding the decrease of kahweol and cafestol contents during coffee roasting, but it has been reported that these compounds can undergo dehydration under heat. Kahweol and cafestol were quantified in Arabica and Robusta coffees with different roasting degrees (2, 4, 6, 8 and 10 min at 230 °C). The structures of the diterpenes and the presence of derivative compounds were determined by liquid chromatography with UV–Vis and mass spectrometry detection. In the dark roast samples, dehydro derivatives were found. The roasting process influenced the level of diterpenes in both species of coffee, but the effect was dependent on the intensity of the process. Cafestol and kahweol were degraded (general losses from 60 to 75 % on a lipid basis) to dehydrocafestol and dehydrokahweol, respectively, after 8 min of process, which corresponds to the commercial roasting degree. On the other hand, the amounts of cafestol and kahweol (mg/100 g of coffee) remained stable during the roasting process due to relative increase in lipid concentration.
      PubDate: 2014-12-01
       
  • Trans-caryophyllene suppresses tumor necrosis factor (TNFα)-induced
           inflammation in human chondrocytes
    • Abstract: Abstract Proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) have been shown to be associated with the pathogenesis of cartilage damage in arthritis. Trans-caryophyllene (TC) is an important constituent of the essential oils of several species of plants. In this study, we found that TC treatment could inhibit TNF-α-induced matrix metallopeptidase 13, cyclooxygenase-2, and prostaglandin E2 (PGE2) production in human chondrocytes. Moreover, the increase in inducible nitric oxide synthase expression and NO production induced by TNF-α was able to be suppressed by TC treatment. Importantly, treatment with TC was also found to inhibit activation of the main proinflammatory regulator, interferon regulatory factor-1, which is increased in the presence of TNF-α. Interestingly, we also proved that TC’s effects on these mechanisms are dependent on the type 2 cannabinoid receptor. Taken together, the results of this study show that TC exerts anti-inflammatory effects in TNF-α-stimulated chondrocyte models.
      PubDate: 2014-12-01
       
  • Effect of yeast physiological indexes on proteinase A secretion detected
           by resonance light scattering technique
    • Abstract: Abstract A simple and sensitive method was developed for the determination of protease A activity (PAA) using the resonance light scattering (RLS) technique. The PAA was measured by a spectrofluorimeter (468 nm, 40 °C, pH 3.0). This method was rapid and convenient with low detection limit of detection (0.662 µg/ml), wide linear range (1–500 µg/ml), and long-term stability (at least 150 min). Using the established RLS method, impact factors of proteinase A secretion were investigated from the angle of yeast strains, physiological state, the generation time (GT), yeast vitality (VT) and yeast mortality. The results showed that there were great differences among the PAA from different yeast strains. For the yeast in the stationary stage, the PAA ascended significantly. The PAA in the yeast with long GT was larger than that with short GT. Early in the fermentation process, the yeast did not secrete proteinase A, but during the final fermentation process, the PAA increased gradually. Meanwhile, The PAA was proportional to yeast mortality, and inversely proportional to yeast VT. Therefore, it is important to select a favorable yeast strains with a shorter GT, higher VT, and lower mortality to produce beers with good foam performance.
      PubDate: 2014-12-01
       
  • Suitability of instrumental analysis for the discrimination between
           wild-caught and conventionally and organically farmed shrimps
    • Abstract: Abstract Shrimps, primarily Penaeus monodon and Litopenaeus vannamei, from organic and conventional farms and free-living stocks were purchased from the German market over 1 year. This study examined the applicability of established analytical methods for the confirmation of the correct labelling of shrimp products. After species identification of 77 shrimp products, the proximate composition, carotenoid pattern, fatty acid profile and stable isotopes of carbon and nitrogen in the lipids and/or the defatted dry matter (DDM) were determined. To differentiate between the three types of production (wild, organically farmed or conventionally farmed), parameters alone or in combination, partly derived by multivariate tests, were considered. Stable isotope ratio mass spectrometry allowed the differentiation between organically and conventionally farmed Litopenaeus vannamei using the combination of ∆δ13C and δ15NDDM values. The gas chromatographic analysis of fatty acids also distinguished between organically and conventionally farmed shrimp of this species. The ratio of the free astaxanthin configurational isomers in shrimp flesh, analysed by high-performance liquid chromatography (HPLC), was inadequate for any assignment, because of the apparent ability to alter the structure of the ingested carotenoids. Thus, a general differentiation of the three production types, irrespective of individual species, could not be achieved by any single method.
      PubDate: 2014-12-01
       
  • Investigation of incurred single- and multi-component model food matrices
           
    • Abstract: Abstract For detection and quantification of food proteins triggering hypersensitivity reactions, reliable, validated analytical methods are necessary. At present, the most commonly used methodology for this purpose is ELISA. The lack of incurred reference materials (RM) complicates the fulfilling of method validation. Today, a well identifiable research direction is the development of methods (immunoanalytical, PCR and MS methods) suitable for multi-component analysis. As a consequence of these R+D efforts, the development of multi-component RMs is reasonable. Our work presented here is focusing on the development and investigation of multi-component model food matrices that can be suitable for supporting the validation processes. On the basis of the relative incidence of hypersensitivity reactions, four components—wheat, milk, egg and soy—were selected for our preliminary work. The target proteins were determined in single- and multi-component matrices with different ELISA methods, and the results were compared by statistical evaluation. The main direction of our investigation was to identify the effects of the potential interactions of these proteins on the analytical results, and the influence of food processing was also investigated. The results showed that the presence of multiple allergenic components caused much less uncertainty in the analytical results than analytical and technological steps, such as sample preparation, repetition or even heat treatment. However, probably due to the relatively complex matrices, some discrepancies from the expected outcome could also be observed.
      PubDate: 2014-12-01
       
  • Effect of sulfur dioxide addition in wild yeast population dynamics and
           polyphenolic composition during spontaneous red wine fermentation from
           Vitis vinifera cultivar Agiorgitiko
    • Abstract: Abstract The aim of the present study was to assess the effect of sulfur dioxide addition in the wild yeast population dynamics as well as the polyphenolic composition during spontaneous red wine fermentation from Vitis vinifera cultivar Agiorgitiko. The grapes were crushed and fermentation took place at 21 °C without the addition of any commercial yeast, and with and without the addition of 40 mg L−1 SO2. A combination of culture-dependent and culture-independent techniques was used for wild yeast population dynamics assessment and HPLC analysis for the determination of polyphenolic compounds. Regarding the former, the effect of sulfur dioxide addition was only marginal since Saccharomyces cerevisiae strains dominated the fermentation from the first day; strains belonging to Hanseniaspora spp., Lachancea thermotolerans and Metschnikowia pulcherrima species appeared only occasionally. As far as the polyphenolic content was concerned, it was enhanced with sulfur dioxide addition; however, as time progressed, the differences were reduced, suggesting that the time the juice was in contact with the skins was of greater importance than sulfur dioxide addition.
      PubDate: 2014-12-01
       
  • Role of calcium content in antibacterial activity of donkeys’ milk
           toward E. coli
    • Abstract: Abstract The objective of this study was to investigate the effect of calcium content in raw donkeys’ milk (DM) on its antibacterial activity against Escherichia coli. Antibacterial assay was performed in artificially contaminated milk samples (without and with added CaCl2 and EDTA) incubated at 38 °C (donkeys’ body temperature). The EDTA was added to DM to bind its calcium ions, while CaCl2 was used as the donor of calcium ions. The content of calcium, lysozyme (LYZ) and lactoferrin (LF) as well as pH value were determined in all of the tested milk samples. DM samples showed varying degrees of antibacterial activity against the tested E. coli strains. The milk samples with higher calcium content possessed stronger antibacterial potential toward the tested bacteria. The determinated calcium-dependant antibacterial activity of DM was proved thorough addition of CaCl2 and EDTA to DM. Calcium content in tested samples was in the range from 377.1 to 1,231 mg/l. The LYZ and LF in tested DM were present at concentrations between 0.98–3.74 g/l and 2.2–54.3 mg/l, respectively. LF was not detected in five of the tested samples, and pH values of the samples were in range from 7.11 to 7.25.
      PubDate: 2014-12-01
       
  • The anti-inflammatory and wound healing properties of honey
    • Abstract: Abstract Honey is a natural product produced by bees and has been used for thousands of years as a medicinal agent and dietary supplement. It is known to cure a wide variety of ailments and can be used as a potent anti-inflammatory and wound healing agent. These vital bioactivities of honey are far less well known than its antibacterial, antioxidant, and any other biological activities. Many clinical trials have been reported and revealed that, when honey is applied to wound, there is a decrease in inflammation and will have a soothing effect. There is much evidence for the anti-inflammatory and wound healing effects of honey in terms of publications in modern medical and scientific journals. The exact mechanism of anti-inflammatory activity and wound healing property of honey has yet to be demonstrated. Possibly there are several mechanisms of action. There are also some reports where honey exerts negligible side effects. The article focuses on the components of honey involved in its anti-inflammatory effect, possible mechanism of action, properties of honey responsible for its wound healing activity, and its adverse effects. Overall the review presents the evidence and explanation for the anti-inflammatory and wound healing properties of honey.
      PubDate: 2014-12-01
       
  • Determination of microheterogeneous substitution in shrimp tropomyosin and
           its effect on IgE-binding capacity
    • Abstract: Abstract Tropomyosin (TM), the major shrimp allergen that belongs to a highly conserved protein family, has frequently been investigated owing to its high rate of human consumption. In this study, the sequence microheterogeneity of TMs, irrespective of the organism and differences in the N- and C-termini, from different shrimp species was analyzed. The TM sequences were analyzed using bioinformatics tools and confirmed by dot-blot using human serum. The results showed that all 13 shrimp species share high mutual TM sequence identity values, ranging from 85.5 to 99.7 %, and 60 cases of sequence microheterogeneity were identified in shrimp TM, with a sequence identity ranging from 90.1 to 99.7 %. A total of 719 unique amino acid residue substitutions (that affect 43 residues, 15 % of 284 residues) involving sequence microheterogeneity were characterized, in which 214 substitutions involving 15 residues were located in the epitope regions. About 45 % of these substitutions occurred in the TM sequences that are reported allergens, whereas 43 % of the substitutions occurred overall for the allergenic and nonallergenic TMs. Dot-blot immunoassay revealed that single microheterogeneous mutation of allergic peptides resulted in significant changes in the IgE-binding capacity of the peptides. Overall, microheterogeneous mutations of TM occurred in different shrimp species. These mutations can potentially induce changes in the IgE-binding capacity and might be responsible for variations in the hypersensitivity to different shrimp species.
      PubDate: 2014-12-01
       
  • Impact of ultrasound on egg white proteins as a pretreatment for
           functional hydrolysates production
    • Abstract: Abstract The objective of this study was to investigate the effects of different ultrasound pretreatment on enzymatic hydrolysis of egg white proteins (EWPs) by Alcalase as well as evaluating some functional and antioxidant properties of hydrolysates obtained by various proteases treatment and ultrasound technology. The effects of chosen ultrasound pretreatment parameters including frequency of ultrasonic waves (35 and 40 kHz), temperature (25 and 55 °C), time of pretreatment (15–60 min) and pH of egg white solution (7.00–10.00) were examined. It appeared that controlled ultrasound treatment can improved the hydrolysis process compared with untreated samples, but optimization of the power and length of sonication was important. The optimal ultrasound pretreatment at calorimetric power of 21.3 W and frequency of 40 kHz for 15 min at 25 °C and with naturally basic egg white (pH 9.25) resulted in increased initial rate and equilibrium degree of Alcalase hydrolysis by about 139.8 and 13.86 % compared with the control, respectively. EWP hydrolysates with ≈27.0 % degree of hydrolysis obtained with heat pretreatment and ultrasound pretreatments under optimal conditions were further separated by sequential ultrafiltration into 4 hydrolysate fractions (<1, 1–10, 10–30 and >30 kDa) which were investigated for protein content, peptide yield and antioxidant activity. The hydrolysis after heat pretreatment generated more peptides <1 kDa (19.04 ± 1.02 %) than ultrasound pretreatment did (11.90 ± 0.53 %), whereas the proportion of peptides <10 kDa were higher in the second case (28.80 ± 0.07 vs. 20.46 ± 0.39 %). The fraction obtained by the ultrasound pretreatment containing peptides with a molecular weight between 1 and 10 kDa demonstrated the strongest ABTS radical scavenging efficacy among the fractions (97.54 ± 0.30) with IC50 value of 4.31 mg/mL. Compared with single-enzyme processes, the two-stage enzymatic processes did not significantly improve both antioxidant and functional hydrolysates’ properties.
      PubDate: 2014-12-01
       
  • Ozone fumigation increases the abundance of nutrients in Brassica
           vegetables: broccoli ( Brassica oleracea var. italica) and Chinese cabbage
           ( Brassica pekinensis )
    • Abstract: Abstract B rassicaceae vegetables, among them broccoli and Chinese cabbage, are well recognized due to the nutritional properties. Four-week-old Chinese cabbage and broccoli seedlings were fumigated with O3 for 3 days before being transplanted into the field. The effect of O3 treatment was determined after reaching marketable quality (ca. 10 weeks). The inflorescences of O3-treated broccoli were enriched in vitamin E (α-tocopherol and γ-tocopherol), whereas Chinese cabbage heads had an increased content of anthocyanins and β-carotene. Ozone treatment did not significantly affect the productivity of both examined vegetables.
      PubDate: 2014-11-20
       
  • Comparison of the degradation kinetics of A-type and B-type
           proanthocyanidins dimers as a function of pH and temperature
    • Abstract: Abstract The degradation behaviors of four different proanthocyanidins dimers including B-type (e)picatechin (E)C dimer and A-type (epi)catechin (E)C dimer, A-type (epi)catechin-3-O-gallate (E)CG dimer and A-type (epi)gallocatechin-3-O-gallate (E)GCG dimer as affected by pH and temperature were compared in this study. The results showed that the stability of proanthocyanidins dimers was not only temperature and pH dependent, but also structure dependent. Proanthocyanidins dimers were found to be unstable at pH as low as 1.5 and physiological pH conditions, and they were rather unstable at alkaline conditions and temperature above 25 °C. Among the four dimers tested, B-type (E)C dimer was the least stable, while A-type (E)C dimer was the most stable. In general, B-type dimers showed less stability than A-type ones. The higher the degree of galloylation and the more the hydroxyl groups in the molecular, the less stable the proanthocyanidins dimers.
      PubDate: 2014-11-19
       
 
 
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