IMEKO Event Proceedings Search

   

Page 247 of 977 Results 2461 - 2470 of 9762

Karadimou, C. C., Koletti, A. E., Moschona, A., Gika, H. G., Vlachos, D., Assimopoulou, A. N.
Peach kernel: a potential source for cosmeceuticals

Prunus persica (peach) is one of the most important deciduous fruit tree worldwide. The main waste of peach industrial processing is the kernel. In this study, kernels from four different peach cultivars from Imathia, Greece (kindly donated by the Members of Greek Canners Association) were examined, aiming to exploit kernels as high added value products. The total concentration of phenolic compounds, proteins and sugars was determined using the Folin-Ciocalteau, Bradford and DNS method, respectively. Fatty acids content was characterized by GC-MS analysis and the concentration of amygdalin, a cyanogenic glycoside which is toxic for humans, in samples was determined by LC-MS. The andioxidant activity of kernel extracts was estimated by DPPH? and ABTS?+ assays.
The results showed that peach kernels are rich in unsaturated fatty acids, mainly oleic and linoleic acid. Extracts from cultivar 1 presented the highest concentration of phenolic compounds (4.47 mg/g) and proteins (31.16 mg/g), while extracts from cultivar 2 presented the highest concentration of sugars. The highest concentration of amygdalin was detected in the methanolic extract of cultivar 4. The kernel extracts from all peach cultivars exhibited strong antioxidant activity, with cultivar 4 presenting the highest one. The results indicated that peach kernel is a promising source for unsaturated fatty acids and phenolic compounds possesing strong antioxidant activity and potential use as an active ingredient in cosmeceuticals and food supplements.

Bergamaschi, L., Mandrile, L., Marchis, D., Amato, G., Martra, G., Rossi, A. M.
Neutron Activation Analysis for processed animal proteins and insect meals characterization

Neutron activation analysis (NAA) is a nuclear process used for determining the concentrations of elements in a vast amount of materials. The method is based on neutron activation and therefore requires a source of neutrons such as a nuclear reactor. Radioactive isotopes are formed in the sample after bombardment with neutrons. The radioactive emissions and radioactive decay paths for each element are well known. Using this information, it is possible to study spectra of the emissions of the radioactive sample, and determine the concentrations of the elements within it. Due to the penetrating nature of incident neutrons and resultant gamma rays, the technique provides a true bulk analysis. As different radioisotopes have different half-lives, counting can be delayed to allow interfering species to decay eliminating interference. This analytical method is useful multi-element analyses with minimum detection limits in the sub-ppm range providing an elemental fingerprint of the analyzed sample which can be used for the specific recognition of an unknown sample. In this work NAA was used to study systematic differences in the elemental composition of different zootechnical meals, including processed animal proteins (PAPs) of different species and insect meals. Chemometrics was exploited for variables’ screening and data treatment. The scope of this work is to provide a very specific characterization of meal products that could be fraudulently add to compound feed in view of a species-specific recognition of unknown meals.

Ionescu, V., Manolache, F. A., Todască, C.
NMR Markers for quantitative analisys of the Romanian Lavandula varieties

Romania is among the top ten European countries in terms of plant production for pharmacological use. In our country, 29 varieties belonging to 17 species of medicinal and aromatic plants were approved (Lavandula angustifolia (Corbeanca /92)). Lavanda angustifolia is the most popular variety due to frost resistance.
In this paper, we established markers for quantitative analysis of the major components of Romanian lavandula varieties, based on 1 H-NMR spectroscopy. The spectral data combined with chemometric analysis served as validation tool for lavandula varieties.

Diamantidou, D., Deliyanni, E., Girousi, S.
Development of selective and sensitive electrochemical sensors, based on novel carbonaceous materials

Chemical sensors has received widespread attention during the past two decades because of their rapid, accurate, reproducible, and low-cost methodologies. Carbon paste electrodes (CPEs) are suitable for a variety of applications and many works have been devoted in the development of new sensitive and selective electrode surfaces based on carbon paste. The application of novel and promising carbonaceous materials, as electrode surfaces, is an issue of great concern.
In this work, the immobilization of calf thymus dsDNA on alternatively prepared carbonaceous materials is being demonstrated. The alternatively prepared carbonaceous materials that were used was activated carbon (B), HNO3 oxidized activated carbon (B5), Ag impregnated activated carbon BAX-Ag (B-Ag) and graphite oxide (GO). Electrochemical techniques (such as differential pulse voltammetry) were applied, aimed to the use of novel carbonaceous materials at electrochemical DNA sensing.

Markovski, A., Velkoska-Markovska, L., Petanovska-Ilievska, B.
Using computer vision softwares in morphological analyses of European Chestnut (Castanea sativa Mill.) genotypes

It is investigated 20 European Chestnut (Castanea sativa Mill) genotypes from the slopes of Vodno and Skopska Crna mountains in northern part of FYROM during 2014-2015. Tools from two image analyzing softwares - Image J and Tomato analyzer are used in measurements. Among the investigated characteristics of Chestnut genotypes it is noted a large level of polymorphism. The Type 15 is characterized with twice as big nut mass as most of other investigated genotypes. The investigated genotypes show differences in the nut anatomy. The Types 12, 7 and 9 are included in the group with large nuts. The Vodno genotypes are larger in average than the genotypes collected from Skopska Crna mountan. According to CIELab color system the nut skin of genotype 15 is characterized with unusually light brown coloration, while the most attractive are the nuts from the Type 8. The investigated genotypes show differences in the nut anatomy, especially the Type 11 which is characterized with significantly higher value for lobedness degree, small seed coat area and seed coad thickness and low percent of hilum presence. Large differences in the leaves dimension and form are also determined.

Mustatea, G., Ungureanu, E. L., Belc, N., Iorga, E., Apostol, L.
Preliminary steps in validating an ICP-MS method for simultaneously analysis of six metals migration from food contact plastic materials into food simulants

Food contact materials are all materials and articles intended to come into contact with food, such as packaging and containers, kitchen equipment, cutlery and dishes, made from a variety of materials including plastics, rubber, paper and metal.
According to Regulation (EU) no. 10/2011, plastic materials and articles shall not release the following substances in quantities exceeding the specific migration limits below: Barium = 1 mg/kg, Cobalt = 0.05 mg/kg, Copper = 5 mg/kg, Manganese = 0.6 mg/kg and Zinc = 25 mg/kg. These metals migration is analyzed into food simulant B (3% acetic acid solution) as stated in the same Regulation.
Determination of trace metal concentrations in the samples was performed with a Perkin Elmer NexION 300Q ICP-MS (Perkin-Elmer Inc., USA) equipped with cross-flow nebulizer and a Quartz torch. The ICP-MS NexION instrument software was used to control all instrument operations including tuning, data acquisition and data analysis. ICP-MS calibration solutions were prepared by dilution of a commercially available multi-element standard (SPEX CertiPrep) in ultrapure water and five-point calibration was performed for all the elements analyzed.
In the first phase of the method validation plan the following parameters were determined: linearity, limit of detection, limit of quantification and recovery. In all cases, correlation coefficients of the calibration curves were higher than 0.996.

Velkoska-Markovska, L., Petanovska-Ilievska, B., Markovski, A.
Development and validation of RP-HPLC method for determination of pesticide residues in apple juice

This study presents development and validation of a reversed-phase high-performance liquid chromatography (RP-HPLC) method for qualitative and quantitative determination of 2,4-D ((2,4-dichlorophenoxy)acetic acid), atrazine, malathion, fenitrothion and parathion residues in apple juices. Specificity, selectivity, linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ) were tested for the method validation and all performance characteristics were found within acceptance criteria.

Kozma, G., Kukovecz, Á., Kónya, Z.
Preparation of environmentally benign zero valent iron nanoparticles for removing soil contaminants

In this paper we present a comparative evaluation of green and semi-green synthesis methods. The former utilized coffee, green tea and Virginia creeper leave extracts, the latters were based on sodium dithionite and sodium borohydride. nZVI synthesis was done in untreated tap water at room temperature to reduce the environmental footprint of the process. nZVI performance was assessed on the basis of time- dependent oxidation/reduction potential measurements and by the reductive dehalogenation of volatile chlorinated organics.

Volpe, M. G., Siano, F., Vasca, E. Medugno, A., La Cara, F.
Extra virgin olive oils quality assessment by ATR-FTIR spectroscopy

One of the most important parameter for the quality determination of extra virgin olive oils, as established by the European Community legislation, is the percentage of free fatty acids. The olive oils classification is governed by the Commission Delegated Regulation (EU) N° 2015/1830 amending the EEC Regulation N° 2568/91 concerning the characteristics of olive oil and olive-pomace oils and the related methods. The regulation fix a total acidity value, for the extra virgin olive oils, = 0.8% of total acidity expressed as oleic acid percentage. Several analytical methodologies have been described for the evaluation of fatty acids contents. These methods, however, need of a time-consuming samples preparation, use of solvents and reagents. Here we present preliminary data on the use of Fourier transform infrared (FTIR) spectroscopy in ATR modality to analyze the free fatty acids content in samples belong to different olive cultivars. The results demonstrated that, the use of ATR-FTIR spectroscopy allowed a determination of fatty acids content faster and affordable in comparison to conventional chemical analyses. Statistical analyses on FTIR spectra allowed the comparison of different samples. The statistical value are been plotted using a Assured ID software that provide overall comparison of the different type of olive oils collected from several geographical locations. The differences are due to factors such as types of soil, water availability, pH, weather, etc. These factors can influence the distance and the percentage of rejection of SIMCA created by three principle components. SIMCA method analysis was performed using the software Assure I.D Perkin Elmer version 3.0.0132.

Tzemou, M., Parasoglou, V. K., Ioannidou, T., Papadopoulos, V., Mitlianga, P., Kasapidou, E.
Prediction of chemical composition of Greek traditional sausages by Near-Infrared Reflectance Spectroscopy

The potential of Near Infrared Reflectance (NIR) spectroscopy to predict the chemical composition of traditional sausages was evaluated. Proximate composition was determined with reference methods. Calibration coefficients and standard errors were 0.92 and 1.66 (moisture), 0.90 and 0.10 (ash), 0.88 and 0.86 (protein) and 0.96 and 1.47 (fat). Cross validation coefficients and standard errors were 0.87 and 1.93 (moisture), 0.74 and 0.16 (ash), 0.75 and 1.21 (protein) and 0.92 and 1.98 (fat). NIR spectroscopy can be applied for the prediction of moisture and fat content of sausages.

Page 247 of 977 Results 2461 - 2470 of 9762