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Diabetologia Notes de lecture     Hybrid Journal  
Diabetology Intl.     Hybrid Journal   (Followers: 1, SJR: 0.273, h-index: 5)
Dialectical Anthropology     Hybrid Journal   (Followers: 9, SJR: 0.314, h-index: 9)
Die Weltwirtschaft     Hybrid Journal   (Followers: 2)
Differential Equations     Hybrid Journal   (Followers: 2, SJR: 0.364, h-index: 15)
Differential Equations and Dynamical Systems     Hybrid Journal   (Followers: 1, SJR: 0.63, h-index: 7)
Digestive Diseases and Sciences     Hybrid Journal   (Followers: 4, SJR: 1.19, h-index: 89)
Directieve therapie     Hybrid Journal  
Discrete & Computational Geometry     Hybrid Journal   (Followers: 3, SJR: 1.269, h-index: 40)
Discrete Event Dynamic Systems     Hybrid Journal   (Followers: 3, SJR: 0.42, h-index: 32)
Distributed and Parallel Databases     Hybrid Journal   (Followers: 4, SJR: 0.766, h-index: 30)
Distributed Computing     Hybrid Journal   (Followers: 2, SJR: 1.41, h-index: 31)
DNP - Der Neurologe und Psychiater     Full-text available via subscription  
Documenta Ophthalmologica     Hybrid Journal   (Followers: 2, SJR: 0.946, h-index: 40)
Doklady Biochemistry and Biophysics     Hybrid Journal   (Followers: 2, SJR: 0.2, h-index: 10)
Doklady Biological Sciences     Hybrid Journal   (SJR: 0.248, h-index: 10)
Doklady Botanical Sciences     Hybrid Journal  
Doklady Chemistry     Hybrid Journal   (SJR: 0.272, h-index: 12)
Doklady Earth Sciences     Hybrid Journal   (SJR: 0.48, h-index: 17)
Doklady Mathematics     Hybrid Journal   (SJR: 0.345, h-index: 13)
Doklady Physical Chemistry     Hybrid Journal   (SJR: 0.299, h-index: 12)
Doklady Physics     Hybrid Journal   (Followers: 1, SJR: 0.293, h-index: 17)
Douleur et Analg├ęsie     Hybrid Journal   (SJR: 0.113, h-index: 6)
Drug Delivery and Translational Research     Hybrid Journal   (Followers: 2, SJR: 0.607, h-index: 8)
Drug Safety - Case Reports     Open Access   (Followers: 1)
Drugs : Real World Outcomes     Hybrid Journal   (Followers: 2)
Dynamic Games and Applications     Hybrid Journal   (Followers: 2, SJR: 0.481, h-index: 5)
Dysphagia     Hybrid Journal   (Followers: 86, SJR: 0.822, h-index: 52)
e & i Elektrotechnik und Informationstechnik     Hybrid Journal   (Followers: 9, SJR: 0.279, h-index: 9)
e-Neuroforum     Hybrid Journal  
Early Childhood Education J.     Hybrid Journal   (Followers: 13, SJR: 0.466, h-index: 16)
Earth Science Informatics     Hybrid Journal   (Followers: 3, SJR: 0.282, h-index: 7)
Earth, Moon, and Planets     Hybrid Journal   (Followers: 7, SJR: 0.303, h-index: 29)
Earthquake Engineering and Engineering Vibration     Hybrid Journal   (Followers: 7, SJR: 0.482, h-index: 21)
Earthquake Science     Hybrid Journal   (Followers: 8, SJR: 0.418, h-index: 9)
East Asia     Hybrid Journal   (Followers: 8, SJR: 0.18, h-index: 9)
Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity     Hybrid Journal   (Followers: 13, SJR: 0.362, h-index: 27)
EcoHealth     Hybrid Journal   (Followers: 3, SJR: 0.88, h-index: 26)
Ecological Research     Hybrid Journal   (Followers: 8, SJR: 0.847, h-index: 43)
Economia e Politica Industriale     Hybrid Journal  
Economia Politica     Hybrid Journal   (SJR: 0.375, h-index: 6)
Economic Botany     Hybrid Journal   (Followers: 8, SJR: 0.527, h-index: 44)
Economic Bulletin     Hybrid Journal   (Followers: 4)
Economic Change and Restructuring     Hybrid Journal   (SJR: 0.264, h-index: 9)
Economic Theory     Hybrid Journal   (Followers: 16, SJR: 2.557, h-index: 34)
Economic Theory Bulletin     Hybrid Journal   (Followers: 2)
Economics of Governance     Hybrid Journal   (Followers: 2, SJR: 0.408, h-index: 14)
Ecosystems     Hybrid Journal   (Followers: 23, SJR: 1.909, h-index: 93)
Ecotoxicology     Hybrid Journal   (Followers: 9, SJR: 1.333, h-index: 56)
Education and Information Technologies     Hybrid Journal   (Followers: 73, SJR: 0.366, h-index: 16)
Educational Assessment, Evaluation and Accountability     Hybrid Journal   (Followers: 17, SJR: 0.374, h-index: 15)
Educational Psychology Review     Hybrid Journal   (Followers: 20, SJR: 2.776, h-index: 61)
Educational Research for Policy and Practice     Hybrid Journal   (Followers: 8, SJR: 0.273, h-index: 9)
Educational Studies in Mathematics     Hybrid Journal   (Followers: 14, SJR: 0.825, h-index: 32)
Educational Technology Research and Development     Partially Free   (Followers: 62, SJR: 1.785, h-index: 52)
Electrical Engineering     Hybrid Journal   (Followers: 16, SJR: 0.336, h-index: 18)
Electrocatalysis     Hybrid Journal   (SJR: 0.883, h-index: 10)
Electronic Commerce Research     Hybrid Journal   (Followers: 3, SJR: 0.582, h-index: 16)
Electronic Markets     Hybrid Journal   (Followers: 5, SJR: 0.411, h-index: 8)
Electronic Materials Letters     Hybrid Journal   (Followers: 3, SJR: 1.407, h-index: 15)
Elemente der Mathematik     Hybrid Journal   (Followers: 1)
Emergency Radiology     Hybrid Journal   (Followers: 5, SJR: 0.678, h-index: 25)
Emission Control Science and Technology     Hybrid Journal   (Followers: 1)
Empirica     Hybrid Journal   (Followers: 3, SJR: 0.319, h-index: 16)
Empirical Economics     Hybrid Journal   (Followers: 8, SJR: 0.489, h-index: 31)
Empirical Software Engineering     Hybrid Journal   (Followers: 7, SJR: 1.285, h-index: 39)
Employee Responsibilities and Rights J.     Hybrid Journal   (Followers: 3, SJR: 0.361, h-index: 15)
Endocrine     Hybrid Journal   (Followers: 7, SJR: 0.878, h-index: 57)
Endocrine Pathology     Hybrid Journal   (Followers: 2, SJR: 0.638, h-index: 31)
Energy Efficiency     Hybrid Journal   (Followers: 14, SJR: 0.732, h-index: 14)
Energy Systems     Hybrid Journal   (Followers: 14, SJR: 1.176, h-index: 7)
Engineering With Computers     Hybrid Journal   (Followers: 5, SJR: 0.433, h-index: 30)
Entomological Review     Hybrid Journal   (Followers: 7, SJR: 0.144, h-index: 5)
Environment Systems & Decisions     Hybrid Journal   (Followers: 2)
Environment, Development and Sustainability     Hybrid Journal   (Followers: 32, SJR: 0.419, h-index: 29)
Environmental and Ecological Statistics     Hybrid Journal   (Followers: 6, SJR: 0.458, h-index: 32)
Environmental and Resource Economics     Hybrid Journal   (Followers: 18, SJR: 1.632, h-index: 54)
Environmental Biology of Fishes     Hybrid Journal   (Followers: 5, SJR: 0.725, h-index: 58)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 2, SJR: 0.741, h-index: 28)
Environmental Earth Sciences     Hybrid Journal   (Followers: 12, SJR: 0.724, h-index: 63)
Environmental Economics and Policy Studies     Hybrid Journal   (Followers: 5, SJR: 0.524, h-index: 4)
Environmental Evidence     Open Access   (Followers: 1)
Environmental Fluid Mechanics     Hybrid Journal   (Followers: 3, SJR: 0.437, h-index: 24)
Environmental Geochemistry and Health     Hybrid Journal   (Followers: 3, SJR: 1.013, h-index: 36)
Environmental Geology     Hybrid Journal   (Followers: 11)
Environmental Health and Preventive Medicine     Hybrid Journal   (Followers: 3, SJR: 0.522, h-index: 19)
Environmental Management     Hybrid Journal   (Followers: 38, SJR: 0.942, h-index: 66)
Environmental Modeling & Assessment     Hybrid Journal   (Followers: 11, SJR: 0.533, h-index: 31)
Environmental Monitoring and Assessment     Hybrid Journal   (Followers: 23, SJR: 0.685, h-index: 52)
Environmental Science and Pollution Research     Hybrid Journal   (Followers: 14, SJR: 0.885, h-index: 46)
Epileptic Disorders     Hybrid Journal   (SJR: 0.608, h-index: 38)
EPJ A - Hadrons and Nuclei     Hybrid Journal   (Followers: 1, SJR: 1.287, h-index: 63)
EPJ B - Condensed Matter and Complex Systems     Hybrid Journal   (Followers: 2, SJR: 0.731, h-index: 89)
EPJ direct     Hybrid Journal  
EPJ E - Soft Matter and Biological Physics     Hybrid Journal   (Followers: 1, SJR: 0.641, h-index: 62)
EPMA J.     Open Access   (SJR: 0.284, h-index: 6)
ERA-Forum     Hybrid Journal   (Followers: 3, SJR: 0.128, h-index: 3)
Erkenntnis     Hybrid Journal   (Followers: 15, SJR: 0.621, h-index: 16)
Erwerbs-Obstbau     Hybrid Journal   (SJR: 0.206, h-index: 9)
Esophagus     Hybrid Journal   (SJR: 0.311, h-index: 10)

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Journal Cover European Food Research and Technology
  [SJR: 0.803]   [H-I: 56]   [8 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  [2279 journals]
  • Assessment of antioxidant properties of alpha-keto acids in vitro and in
           vivo
    • Abstract: Abstract The antioxidant properties of three alpha-keto acids, pyruvate, oxaloacetate and alpha-ketoglutarate were tested in vitro and in vivo. In vitro, the keto acids demonstrated a good H2O2-scavenging activity, but were less effective as scavengers of free radicals or reductants of oxidized compounds. Alpha-ketoglutarate was a more effective H2O2 scavenger as well as HO· in Fe3+–ascorbate–EDTA–H2O2 system than other keto acids. All keto acids did not demonstrate iron-chelating activity. It was supposed that ability of keto acids to inhibit HO· production in the Fenton reaction could be mainly conditioned by their H2O2-scavenging activity. In vivo experiments, the addition of alpha-keto acids to the incubation medium significantly increased the resistance of exponentially growing yeast Saccharomyces cerevisiae cells to H2O2, transition metal ions (Fe2+), but not to menadione, a superoxide anion-generating compound. Similar results were obtained on fruit fly Drosophila melanogaster. In particular, co-treatment with alpha-ketoglutarate enhanced resistance of adult flies to H2O2 and did not prevent menadione-induced death of flies. Collectively, the results obtained indicate that exogenous alpha-keto acids as antioxidants are able efficiently to protect living organisms against stressors in which effects are mediated by H2O2. Therefore, they can be considered as available natural supplements to alleviate the harmful effects of reactive oxygen species.
      PubDate: 2016-02-01
       
  • Characterization of crude ovomucins obtained from various egg white layers
    • Abstract: Abstract Structurally, egg white (EW) is composed of four distinct layers: outer thin white, thick white, inner thin white and chalaziferous layer (including chalaza cords). In addition, the thick white can be further separated into a gel and a liquid fraction by using ultracentrifugation. There were large differences in the amounts of various ovomucin complex forms between the EW layers, but more or less the order was about the same despite the ovomucin form. The three most ovomucin-rich fractions were: chalaziferous layer > gel fraction of thick EW layer > thick EW layer. Furthermore, each ovomucin fraction was also degraded by using enzymatic hydrolysis. Only three hydrolysed ovomucin fractions were found to contain hemagglutination inhibition activity against Newcastle disease virus, namely thick white, inner thin white and the gel fraction of thick white. Moreover, both thick EW and gel fraction ovomucin showed antiviral activity against avian influenza virus subtype H5. In addition, gel fraction ovomucin also inhibited avian influenza virus subtype H7. All three ovomucin hydrolysates having hemagglutination inhibition activity also contained the highest amount of sialic acid. Structural characterization of ovomucin revealed that it is composed of two subunits, α- and β-ovomucins, as EW protein formerly called α1-ovomucin seemed to be ovostatin. However, it seemed quite possible that ovostatin is associated within β- and α-ovomucins. This interaction might even have some effect on the physical nature of various EW layers.
      PubDate: 2016-02-01
       
  • Synthesis and accumulation of anthocyanins in sour cherries during
           ripening in accordance with antioxidant capacity development and chalcone
           synthase expression
    • Abstract: Abstract Phytonutrient metabolism in sour cherries takes place during fruit ripening. This study demonstrated that total phenolic–flavonoid contents decline during ripening while total anthocyanin content significantly increases at the same period. There were no detectable anthocyanins in green cherry fruits. Anthocyanin biosynthesis started concurrently with color formation. Cyanidin-3-glucosylrutinoside and cyanidin-3-rutinoside were the early anthocyanins accumulated in fruits and were accompanied with cyanidin-3-sophoroside and cyanidin-3-glucoside in fully ripe fruits. Phenylpropanoid pathway involves anthocyanin biosynthesis, and chalcone synthase (CHS) is one of the key enzymes regulating the pathway. Three CHS genes (PcChs1, PcChs2, PcChs3) were isolated from sour cherry genome, and their transcription profiles were determined using the RT-PCR approach. There was no CHS gene expression before breaker stage, and PcChs1, PcChs2, PcChs3 transcription were upregulated in parallel with pigmentation in sour cherry cells and PcChs1 had the highest transcripts in fully ripe fruits.
      PubDate: 2016-02-01
       
  • Fatty acid composition and tocopherol content of the kernel oil from
           apricot varieties (Hasanbey, Hacihaliloglu, Kabaasi and Soganci) collected
           at different harvest times
    • Abstract: Abstract The oil content of ‘Hasanbey’ apricot kernels (Prunus armeniaca L.) was created from harvest-1 (14.6.2011) (35.80 %; v/w) and harvest-4 (6.7.2011) (49.00 %; v/w). In addition, the oil content of ‘Kabaasi’ apricot kernels is created from 28.0 to 49.2 % (v/w) between the same harvests. The oleic acid of ‘Hasanbey’ nut oil is created from 42.94 to 59.13 % (v/w) from harvest-1 to harvest-4. The linoleic acid concentration in the same variety ranged from 44.99 to 31.71 % (v/w) depending on harvest times. In addition, ‘Hacihaliloglu’ apricot nut oil contained 45.74 % (harvest-1) to 66.79 % (harvest-4) oleic acid and 43.50 (v/w) to 24.43 % (v/w) linoleic acid at harvest-1 and harvest-4, respectively. The γ-tocopherol content of Hacihaliloglu ranged from 47.63 mg/100 g (v/w) to 27.15 mg/100 g depending on maturation.
      PubDate: 2016-02-01
       
  • Comparison of the experimentally obtained growth model of Listeria
           monocytogenes on cucumber and zucchini with existing model generated by
           ComBase Predictor
    • Abstract: Abstract The quality and microbiological safety of produced and stored food is a challenge for its producers and official control. Numerous examples have shown how important it is for them to have access to precise data about the growth time and rate of microorganisms in stored products, especially in the case of those which are the etiology of digestive system diseases such as Listeria monocytogenes. It is one of the most virulent foodborne pathogens, showing a mortality rate of approximately 20–30 %, which is the highest among food microbiota. In order to determine the microbial growth kinetics in time on food matrices, so-called growth modeling is used. It allows to determine the growth of microorganisms in time and depending on the temperature, pH, water activity (a w), or content of acids. In this paper, we verified the growth model of Listeria monocytogenes on cucumber and zucchini with an existing model in the ComBase Predictor.
      PubDate: 2016-02-01
       
  • Antihypertensive peptide purified from Styela clava flesh tissue
           stimulates glucose uptake through AMP-activated protein kinase (AMPK)
           activation in skeletal muscle cells
    • Abstract: Abstract Previously, our group described an antihypertensive peptide (Ala-His-Ile-Ile-Ile, MW: 565.3 Da) with angiotensin I-converting enzyme inhibitory and vasodilatory effects that was purified from Styela clava flesh tissue. In the present study, we investigated the metabolic effects of the antihypertensive peptide in skeletal muscle cells. We found that the antihypertensive peptide stimulated glucose uptake in differentiated L6 rat myoblast cells in a dose-dependent manner. Inhibition of AMP-activated protein kinase (AMPK) by compound C significantly inhibited the antihypertensive peptide-stimulated glucose uptake. Western blotting analyses revealed that the antihypertensive peptide stimulated AMPK phosphorylation and this enhancement could be specifically inhibited by compound C. Furthermore, the current study demonstrates that translocation of glucose transporter-4 (GLUT4) to the plasma membrane was stimulated by the antihypertensive peptide. In summary, the findings from this study suggest that the antihypertensive peptide may have beneficial effects on the glucose metabolism in skeletal muscle cells via a mechanism involving AMPK and possible stimulation of the intrinsic activity of GLUT4 transporter.
      PubDate: 2016-02-01
       
  • Modeling of Listeria monocytogenes inactivation by combined high-pressure
           and mild-temperature treatments in model soup
    • Abstract: Abstract High-pressure processing (HPP) in combination with mild heat is known to have a synergistic effect on bacterial inactivation in broth, milk and meat. This synergistic effect has, however, not been documented for a ready-to-eat (RTE) soup. In this study, Listeria monocytogenes inactivation in a model RTE soup under combined high-pressure and mild-temperature (P/T) treatments was modeled according to a central composite design. The model was significant (P < 0.0001) with a satisfactory predictability (R adj 2  = 0.95). Effects of P/T on L. monocytogenes inactivation were assessed by solving the deduced quadratic equation and analyzing its contour plot. More than 6-log inactivation of Listeria was possible at combined P/T ranges of 525 MPa/40 °C to 600 MPa/25 °C within 5 min. This was in accordance with FDA and EC guidance on refrigerated RTE foods that a treatment intensity equivalent to 6-log reduction of L. monocytogenes would be required as a listericidal control measure. Moreover, 600 MPa treatments at ≥45 °C for 5 min resulted in no L. monocytogenes recovery in the model soup during 3 weeks at 4 and 8 °C when the inoculum size was 103 or 105 CFU/ml. Results clearly indicated that use of mild temperatures in combination with HPP can induce a more complete inactivation, hence reducing the microbial recovery in foods after HPP. Experimental results and the fitted model in this study may be utilized as a comparison to other inactivation models and for determining test conditions for process safety assessments on similar refrigerated products in food industry.
      PubDate: 2016-02-01
       
  • Profiling and identification of the metabolites of ginsenoside Ro in rat
           faeces and urine after oral administration
    • Abstract: Abstract Ginsenoside Ro is one of the high-abundance saponins in ginseng, which is the most widely used dietary supplement and has many health-promoting effects. However, knowledge regarding the metabolism of ginsenoside Ro is notably limited. The profiling and identification of metabolites of ginsenoside Ro using high-performance liquid chromatography tandem mass spectrometry (HPLC MS/MS) was described in this work. There were finally 14 metabolites in addition to the parent drug that were identified in both faeces and urine of rats after oral administration of pure ginsenoside Ro (200 mg/kg). Quantitative analyses of six of the most abundant metabolites were then performed using ultra-performance liquid chromatography tandem mass spectrometry (UPLC MS/MS). Total recovery of ginsenosides over 72 h was approximately 60 %. There was approximately 0.07 % of ginsenoside Ro observed as excreted in the urine. The hydrolysis of the glycosidic bond on the aglycone was the primary pathway for ginsenoside Ro. These hydrolysis processes are nonselective.
      PubDate: 2016-02-01
       
  • Mineral and volatile composition of água - mel from Portugal
    • Abstract: Abstract Água-mel (honey–water) is a typical honey-based product produced by the Portuguese beekeepers, particularly in southern Portugal. Água-mel was characterized by mineral content and volatiles contents. Mineral content evaluation was performed based on a random sampling of 14 samples from a total of 16 samples provided by local producers. Mineral content showed that potassium predominated in água-mel samples (1270–4105 mg/kg). The concentration of aluminium in one sample was tenfold higher (5.8 mg/kg) than in the remaining samples (0.3–0.6 mg/kg). Água-mel volatiles were isolated by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS) from a subset of eight samples. Cluster analysis showed two poorly correlated clusters (S corr < 0.3). Cluster I only sample was dominated by trans-β-ocimene (19 %), γ-terpinene (15 %) and 2-furfural (9 %). Cluster II that included the remaining seven samples showed two moderately correlated subclusters (S corr < 0.5). The six samples with high correlation from subcluster IIa were dominated by 2-furfural (18–41 %) and benzene acetaldehyde (12–39 %). n-Nonadecane (14 %), n-heneicosane and 2-furfural (both 13 %) were the main components of subcluster IIb sample. Although the presence of some volatile compounds can help in the correlation between água-mel and honey botanical source, the final product varies largely according to the preparation process even for the same producer, in different years. Água-mel detailed characterization may assist in bringing added value to this typical Portuguese honey-based product.
      PubDate: 2016-02-01
       
  • Detection of green pea adulteration in pistachio nut granules by using
           Raman hyperspectral imaging
    • Abstract: Abstract A rapid and nondestructive method for determination of green pea adulteration in pistachio nut granules was demonstrated using Raman hyperspectral imaging combined with principal component analysis and partial least squares regression (PLSR). Pistachio nut granule samples were adulterated with green pea granules at different concentrations ranging from 20 to 80 % (w/w). Hyperspectral Raman images were acquired in the wavenumber range of 200–3700 cm−1 by using a 1064-nm laser. PLSR model was developed for predicting the content of the green pea adulteration in pistachio nut granules. Based on the whole spectral data, good prediction model was obtained with a coefficient of determination (R 2) value of 0.99 and root-mean-square error of prediction value of 0.048. The results showed that hyperspectral imaging is beneficial for determining the adulteration of pistachio nuts with a time-saving and nondestructive method, which is important to confirm food quality and safety.
      PubDate: 2016-02-01
       
  • Using jasmonates and salicylates to reduce losses within the fruit supply
           chain
    • Abstract: Abstract The fresh produce industry is constantly growing, due to increasing consumer demand. The shelf-life of some fruit, however, is relatively short, limited by microbial contamination or visual, textural and nutritional quality loss. Thus, techniques for reducing undesired microbial contamination, spoilage and decay, as well as maintaining product’s visual, textural and nutritional quality are in high demand at all steps within the supply chain. The postharvest use of signalling molecules, i.e. jasmonates and salicylates, seems to have unexplored potential. The focus of this review is on the effects of treatment with jasmonates and salicylates on the fresh produce quality, defined by decay incidence and severity, chilling injury, maintenance of texture, visual quality, taste and aroma, and nutritional content. Postharvest treatments with jasmonates and salicylates have the ability to reduce decay by increasing fruit resistance to diseases and reducing chilling injury in numerous products. These treatments also possess the ability to improve other quality characteristics, i.e. appearance, texture maintenance and nutritional content. Furthermore, they can easily be combined with other treatments, e.g. heat treatment and ultrasound treatment. A good understanding of all the benefits and limitations related to the postharvest use of jasmonates and salicylates is needed, and relevant information has been reviewed in this paper.
      PubDate: 2016-02-01
       
  • Monovarietal extra-virgin olive oil classification: a fusion of human
           sensory attributes and an electronic tongue
    • Abstract: Abstract Olive oil quality grading is traditionally assessed by human sensory evaluation of positive and negative attributes (olfactory, gustatory, and final olfactory–gustatory sensations). However, it is not guaranteed that trained panelist can correctly classify monovarietal extra-virgin olive oils according to olive cultivar. In this work, the potential application of human (sensory panelists) and artificial (electronic tongue) sensory evaluation of olive oils was studied aiming to discriminate eight single-cultivar extra-virgin olive oils. Linear discriminant, partial least square discriminant, and sparse partial least square discriminant analyses were evaluated. The best predictive classification was obtained using linear discriminant analysis with simulated annealing selection algorithm. A low-level data fusion approach (18 electronic tongue signals and nine sensory attributes) enabled 100 % leave-one-out cross-validation correct classification, improving the discrimination capability of the individual use of sensor profiles or sensory attributes (70 and 57 % leave-one-out correct classifications, respectively). So, human sensory evaluation and electronic tongue analysis may be used as complementary tools allowing successful monovarietal olive oil discrimination.
      PubDate: 2016-02-01
       
  • Synergistic, antagonistic and additive interactions of green tea
           polyphenols
    • Abstract: Abstract Green tea is a natural source of polyphenols where their catechins and flavonols are the major components. Their antioxidant activities are the most important biological effect and often the object of study. DPPH (2,2-diphenyl-1-picryl-hydrazyl) radical assay has been carried out to measure the individual scavenging activities expressed as percentage of DPPH inhibition for each tea polyphenol, and (−)-gallocatechin gallate (GCG) (74.04 ± 0.38 %) and (−)-epigallocatechin gallate (EGCG) (69.51 ± 0.27 %) were the most active compounds. Synergistic, antagonistic and additive interactions among catechin derivatives as well as combined with green tea extract have been analyzed, where GCG and EGCG provided most of the synergistic effects. Flavonols such as quercetin (54.61 ± 0.21 %) and kaempferol (24.06 ± 0.02 %) also showed free radicals’ scavenging activity. Interactions between flavonols and individual catechins as well as their mixtures in the tea extract have been investigated. The results suggested that the presence of tea flavonols in tea extract provided additive interactions and the tea catechins were responsible for synergism in green tea. This work can be the starting point of the research about supplemented green tea from its own catechins to increase the total antioxidant capacity of the green tea.
      PubDate: 2016-02-01
       
  • Effect of milk fat content on the viscoelasticity of mozzarella-type
           cheese curds
    • Abstract: Abstract The effect of fat content in cheese curds on their rheological properties was examined using dynamic shear measurements. Surplus fat addition to milk samples caused two distinct types of changes in the temperature dependence of the viscoelastic moduli of resultant curds. The first was a significant reduction in the moduli over a wide temperature range, which is attributed to the presence of liquefied fat globules within the milk protein network. The second was the excess contribution to the low-temperature moduli owing to the reinforcing effect of solidified fat globules. An upward shift in the sol–gel phase transition temperature driven by an increased fat content was also observed.
      PubDate: 2016-02-01
       
  • The relationship between the aging of polycarbonate characterized by SEC
           and the release of bisphenol A quantified by HPLC–UV
    • Abstract: Abstract Aging of polycarbonate (PC) and migration of bisphenol A (BPA) from PC in solutions were studied under different conditions of temperature, pH, and treatment duration. In order to investigate the relationship between the migrant and its polymer and explain the release mechanism of the BPA, the impact of different treatments on PC aging was studied by measuring molecular masses using size exclusion chromatography. The BPA which migrates in the solutions was measured using HPLC–UV. It has been found that the molecular weights of PC samples change as the conditions of treatment change. In general, the trend was to shift the Mn toward a lower average molecular weight by increasing treatment temperature, pH, and treatment duration. The findings are in concordance with the BPA concentrations in solutions. The obtained results show clearly that the levels of BPA concentrations increase with temperature, pH, and treatment duration. The BPA released does not only result from degradation mechanism originating from the treatments of the polymer, but also it results from the transport of non-polymerized monomer from the polycarbonate.
      PubDate: 2016-02-01
       
  • Identification and LC–MS/MS-based analyses of technical enzymes in
           wheat flour and baked products
    • Abstract: Abstract The use of technical enzymes in bakery industry is necessary for a consistent and good quality of baked products. Since the cultivation of cereals leads to low amounts of endogenous enzymes being present, a need of their commercial alternatives is becoming a routine process in order to meet the consumer quality demands. Targeted quantification proteomics-based methods are necessary for their detection to meet the regulatory criteria. Here, we initially report on the identification of Lipase FE-01, a lipase from fungus Thermomyces lanuginosus, as analyzed by SDS-PAGE, in-Gel digestion, and MALDI–TOF–MS. In further experiments, the focus of the study was directed toward an extensive use and optimization of in-solution enzymatic digestion in combination with LC–MS/MS techniques in identification of specific peptide markers and finally in utilization of the latter in delivering reproducible quantification data for several different technical enzymes (α-amylases, xylanase, and lipases from microbial origin) in complex matrices such as baked bread and wheat flour. Two digestion protocols (a fast option using thermocycler program and the well-established overnight method) were tested, and both of these can be successfully applied. The application of isotopically labeled analogs of the MRM targeted peptides as internal standards and the addition of an internal protein standard during the extraction/digestion experiment were compared to determine the optimal quantification algorithm of the recovered enzyme concentrations. Thus, a standardized sensitive LC–MS/MS method could be developed to determine technical enzymes as forthcoming ingredients in the prefabricated food formulations in concentrations lower than 10 ppm.
      PubDate: 2016-02-01
       
  • HS-SPME/GC-MS methodologies for the analysis of volatile compounds in cork
           material
    • Abstract: Abstract Two methods based on headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography–ion trap mass spectrometry (GC-IT/MS) were proposed for the analysis of volatile organic compounds (VOCs) in cork material used in the production of cork stoppers. The effect of various factors affecting the extraction efficiency was carried out by means of a 24 full factorial design. The first method allowed the extraction of 17 terpenes by using a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber (50/30 μm). The optimal conditions were achieved when cork extract (5 mL) added with 2.3 g of NaCl was extracted during 35 min at 55 °C. The second method allowed the identification of 41 carbonyl compounds after in-solution (5 mL) derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA, 2.3 mg/mL), followed by an incubation period of 6 min at 52 °C and extraction during 36 min at the same temperature, using a PDMS/DVB (50/30 μm) fiber. Both methods are simple, solvent free and fast. These methods were applied to the analysis of different cork raw material showing significant differences in the amounts of volatile compounds analyzed. Alcanfor and α-terpineol were the terpenes compounds present at highest amounts, and within carbonyl compounds analyzed, some samples presented a high level of butanal, octanal, nonanal, and glyoxal.
      PubDate: 2016-01-28
       
  • Varietal phenolic composition of Probus, Rumenika and Frankovka red wines
           from Fruška Gora (Serbia) and changes in main compounds during
           maceration
    • Abstract: Abstract Red wine is a rich source of different phenolic compounds which contribute to sensorial characteristics and can exhibit various biological properties. The amount of phenolics in wine depends on various factors such as grape variety, environmental conditions and production technology. The extraction of individual polyphenolic compounds during maceration was investigated in this paper. Preliminary determination of specific phenolic compositions in wines produced from grape varieties characteristic for Fruška Gora region (Probus, Frankovka and Rumenika) was also performed. A general trend in extraction of some compounds as well as specific characteristics for each variety regarding phenolic composition was observed. Obtained results showed that among wines of different varieties and vintages, statistically significant differences existed in the content of most analysed phenolics. Wines made from Probus variety were characterised by very high anthocyanin content and Frankovka wines by high content of syringic acid while high contents of piceid (resveratrol), catechin and gallic acid were specific for Rumenika variety. Obtained results have shown that Probus variety has especially great winemaking potential considering high content of phenolic compounds (especially anthocyanins), as well as intensive and stable colour.
      PubDate: 2016-01-25
       
  • Addition of lees from base wine in the production of Bombino sparkling
           wine
    • Abstract: Abstract In this paper, we explored an innovative and sustainable technology to improve the sensorial characteristics of traditional sparkling wine. Different volumes of lees, recovered from the first fermentation, were included into the “liqueur de tirage” for the second fermentation of Bombino grapes base wine. Proteolysis evolution was compared to that of traditional Bombino grapes sparkling wine over 18 months after “dégorgement”, using combined liquid chromatography techniques and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of peptides in the size of 1500–3000 Da range. The addition of lees exhibited a clear impact on proteolysis, most likely due to the hydrolytic enzymes released by yeast autolysis. The profile of volatile organic compounds was assessed by gas chromatography–MS, foam stability, and the sensory traits were both evaluated by a panel of trained testers. The sensory traits were positively influenced by the addition of lees up to 60 mL/L base wine. Therefore, changing the amount of lees addition can be used to modulate the aromatic composition of sparkling wine in an attempt to improve it, and this also allows the shortening of ageing time.
      PubDate: 2016-01-22
       
  • Study of melamine and formaldehyde migration from melamine tableware
    • Abstract: Abstract Two HPLC–UV rapid methods have been developed to quantify and identify melamine, ammeline, ammelide and formaldehyde in samples of melamine plastic kitchenware. Eighteen samples of melamine articles purchased at various markets in Galicia (Spain) and Quito (Ecuador) were analyzed. Melamine analysis was carried out using a HILIC column (150 × 3 mm, 3 µm size of particle) and ammonium formate 10 mM (fitted to pH 3 with formic acid)/acetonitrile (5:95 v/v) as mobile phase. Formaldehyde was reacted with 2,4-dinitrophenylhydrazine, and then the analysis was carried out using a Kromasil ODS (C18) column (150 × 3.20 mm, 5 µm size of particle). A gradient elution method was applied using Milli-Q water and acetonitrile as mobile phase. Articles were exposed to the food simulant acetic acid 3 % (w/v). The test conditions used were repeated exposures to the simulant for 2 h at 70 °C. The methods were validated with respect to linearity, limits of detection and quantification, and repeatability. Melamine migration was detected in 8 of the 18 food contact articles analyzed. However, none of the samples exceeded the specific migration limit (SML) of 2.5 mg/kg on the third exposure. Ammeline and ammelide were not detected in any sample. Formaldehyde migration was detected in all of the samples analyzed, and in 56 % of the samples, formaldehyde levels were above the SML of 15 mg/kg established in European Regulation.
      PubDate: 2016-01-22
       
 
 
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