23 research outputs found
Morphological characteristics of Greek Strawberry tree (Arbutus andrachne L.) genotypes
The morphological characteristics of fruits and leaves of ten Greek Strawberry tree (Arbutus andrachne L.) genotypes located on the middle course, from the left side of Konjska River, in South part of Republic of Macedonia are investigated. Among the investigated characteristics of Greek Strawberry tree genotypes it is noted a large level of polymorphism. The genotype 2 is characterized with twice as big fruit mass (1.87 g) as most of other investigated genotypes. The genotypes 2, 7 and 9 are included in the group with large fruits. According to CIELab color system the fruit skin of genotype 2 is characterized with unusually dark red coloration (L* 21.02; a* 18.8; b* 12.0), while the most attractive are the fruits from the genotype 9 (L* 23.9; a* 28.3; b* 17.4). The investigated genotypes show differences in the fruit anatomy, especially the genotype 7 which is characterized with significantly higher value for lobedness degree, pericarp area and pericarp thickness, percent of pulp and number of seeds in fruit. Large differences in the leaves dimension and form are also determined
DETERMINATION OF SOME PESTICIDE RESIDUES IN APPLE JUICE BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
A new, simple and reliable reversed-phase high-performance liquid chromatography (RP-HPLC) method for determination of 2,4-D ((2,4-dichlorophenoxy)acetic acid), atrazine, malathion, fenitrothion and parathion residues in apple juices has been developed and validated. Successful separation and quantitative determination of analytes were performed on Purospher STAR RP-8e (30 x 4 mm, 3 μm) analytical column, with mobile phase consisted of acetonitrile/water (45/55, V/V), flow rate of 1 mL/min, constant column temperature at 25 oC and UV detection at 220 nm and 270 nm. A solid-phase extraction (SPE) was used for concentration and clean-up of analytes. Specificity, selectivity, linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ) were tested for the method validation according to European Commission guidelines for pesticide residue analytical methods, and all performance characteristics were found within acceptance criteria. Calibration curves were linear within the range less than 50 % of the maximum residue limit (MRL) values and 20 % above for all investigated pesticides (R2 > 0.95). Under the stipulated conditions, values for relative standard deviations (RSD) of retention times and peak areas were 0.12 % - 0.28 % and 0.08 % - 8.50 %, respectively. The obtained values for recoveries ranged from 93.65 % - 118.62 %, with RSD ≤ 5.64 %. This method was successfully applied for determination of investigated pesticide residues in apple juice samples, which were taken from Macedonian markets. The run time of assay obtained from this chromatography condition was about 4 min
INVESTIGATION OF ORGANOLEPTIC CHARACTERISTICS OF POMEGRANATE (PUNICA GRANATUM L.) VARIETIES
Investigation of organoleptic characteristics and determination of some biochemical compounds content in the fruit of eight traditional pomegranate (Punica granatum L.) varieties and types: Lifanka, Bejnarija, Karamustafa, Ropkavac, Valandovska kisela, Lifanka clone, Zumnarija and Hicaz, from Valandovo area (North Macedonia), was performed. Fruit from Valandovska kisela and Hicaz varieties are characterized with the lowest value of pH and also with highest content of citric acid. The content of fructose sugar prevails over the content of glucose in 1,1 ratio. Anthocyans are the most common in fruits from Hicaz variety. The Valandovska kisela variety has the highest content of phenols. The fruits from Ropkavac and Zumnarija varieties have the highest content of flavan-3-ols which give them a characteristic flavor. According to organoleptic evaluation of external fruit appearance, the best ranked is the Karamustafa variety. According to the internal characteristics, i.e. the fruit aril, again stood out as the best the Karamustafa variety, by all parameters. The respondents are pointed out also Ropkavac and Bejnarija varieties in evaluation of aril flavor and aroma, such as very good varieties, especially by the aril juiciness. According to all organoleptic (external and internal) characteristics, the highest ranked is Karamustafa variety which is recommended as a perspective variety of pomegranate for spreading in R North Macedonia
Investigation of Aril Characteristics of Some Autochthonous Pomegranate (Punica granatum L) Varieties in Macedonia
The individual aril characteristics of eight autochthonous pomegranate varieties (Lifanka, Bejnarija, Karamustafa, Ropkavac, Valandovska, LC, Zumnarija and Hicaz) from R. Macedonia were investigated using computer vision software methods. The great differences in the dimension of aril at the varieties were determined. The variety Lifanka is characterized with the greatest length (12.6 mm), width (9.5 mm) and mass (0.5 g) of the aril. Cross section aril area (61.1 mm2) and perimeter (31.6 mm) indicate that the variety ‘Hicaz’ is characterized with the smallest aril. Investigation of the aril shape showed different level of asymmetry depending on the variety. Generally, the variety Hicaz is characterized with the most asymmetrical aril. Based on CIELab system of coloration, great differences in the aril colour were noted among the investigated pomegranate varieties. The variety Hicaz had the darkest coloration (L* 19.3; a* 13.1; b* 5.3). High correlation dependence between coloration and shape and mass was determined
Supplementary data for article: Ajaj, I.; Markovski, J.; Rančić, M.; Mijin, D.; Milčić, M.; Jovanović, M.; Marinković, A. Solvent and Structural Effects in Tautomeric 2(6)-Hydroxy-4-Methyl-6(2)-Oxo-1-(Substituted Phenyl)-1,2(1,6)-Dihydropyridine-3-Carbonitriles: UV, NMR and Quantum Chemical Study. Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy 2015, 150, 575–585. https://doi.org/10.1016/j.saa.2015.05.055
Supplementary material for: [https://doi.org/10.1016/j.saa.2015.05.055]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1971
Supplementary data for article: Ajaj, I.; Markovski, J.; Rančić, M.; Mijin, D.; Milčić, M.; Jovanović, M.; Marinković, A. Solvent and Structural Effects in Tautomeric 2(6)-Hydroxy-4-Methyl-6(2)-Oxo-1-(Substituted Phenyl)-1,2(1,6)-Dihydropyridine-3-Carbonitriles: UV, NMR and Quantum Chemical Study. Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy 2015, 150, 575–585. https://doi.org/10.1016/j.saa.2015.05.055
Supplementary material for: [https://doi.org/10.1016/j.saa.2015.05.055]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1971
Arsenic removal by magnetite-loaded amino modified nano/microcellulose adsorbents: Effect of functionalization and media size
Comparative adsorption study related to benefits of parent media size, i.e. microfibrillated cellulose (MC) versus nanocellulose (NC) support, for the preparation of magnetite (MG) based high performance adsorbent for arsenic removal was conducted. Precipitation of MG on amino terminal branched organic structure, L, either linked by maleic acid residue on NC surface (NC-MA/L) or linked by oxalyl bridge on MC surface (MC-O/L) produced NC-MA/L-MG and MC-O/L-MG adsorbents, respectively. Precipitation of nanosized MG on amino functionalized NC-MA/L and MC-O/L, performed according to optimized procedure, contributed to improved textural properties and adsorptive/kinetic performances of novel adsorbents. Adsorption capacity of arsenate, As(V), was in favor of NC-MA/L-MG (85.3 versus 18.5 mg g(-1)) while MC-O/L-MG exhibited faster kinetics (0.541 versus 0.189 g mg(-1) min(-1)). Lower capacity of arsenite, As(III), removal, 68.3 mg g(-1) for NC-MA/L-MG and 17.8 mg g(-1) for MC-O/L-MG, were obtained. Calculated activation energies, 13.28 and 10.87 kJ mol(-1) for NC-MA/L-MG and MC-O/L-MG with respect to As(V), respectively, suggest, in accordance with results of Weber-Morris fitting, that internal mass transfer controls adsorption process. Model free adsorption kinetics confirmed beneficial uses of MC-O/L-MG due to low activation energy dependence on the extent of adsorption
Investigation of the morphometric characteristics of jujube types (Zizyphus jujuba Mill.) fruits in Republic of Macedonia
In the period 2002-2004 have been studied 131 Jujube types in the
experimental orchards of Agricultural Institute in Skopje. They are progeny
derived from six varieties of Jujube: Zu tao czao, Da baj czao, Kitajski 2A,
Wild midleasiatic jujube type, Ja czao, Vahshski 45-2. The seeds of these
varieties were obtained by open pollination. Studies were done on the 7-9
aged plants in full fertility. Characteristics of fruits, fruit dimensions
and mass of fruit were determined. It was established that the variety
Kitajski 2A has the largest fruits (13.1 g). The progeny of the same variety
(Kitajski 2A) is characterized with the largest fruits (8.9 g), and the
progeny of the variety with the smallest fruits between varity-mothers - Da
baj czao is characterized with the smallest fruits (6.3 g). The type 21/6 has
an average the largest fruits (22.2 g), while the smallest are the fruits of
the type 16/4 (1.8 g). The fruits from type 21/6 are bigger than fruits of
the biggest Jujube variety introduced in R Macedonia -Ta jan czao
Анекс проект кон Основен технолошки-машински проект за погонот флотација во „САСА“ – Македонска Каменица За капацитет q = 850.000 t/год.
Овој ороект е изработен како анекс кон Псновниот технолошко-машински ороект за
оогонот флотација во “САСА” – М. Каменица за каоацитет Q=850.000 t/год. изработен од страна
на РИ-ИПИ, РУДАРСКИ ИНСТИТУТ и ДР. Д.П.П. – Скооје во 2007 година.
Проектот е изработен врз основа на Проектната задача и Техничката документација од
рудникот за олово и цинк “САСА” – М. Каменица со цел да се изврши орошируваое на делот
од технолошкиот ороцес што го оофаќа основното и контролното флотираое на оловните
минерали, со монтираое на уште една ќелија од тиоот RCS20. Целта е да се изврши
зголемуваое на времетраеоето на основното флотираое на оловните минерали на тој начин
што тоа би се одвивало во 8 наместо во 7 флотациски ќелии и би изнесувало 26.5 наместо
23.21 минути. Процесот на контролно флотираое на оловните минерали и оонатаму би се
одвивал во 3 флотациски келии од тиоот RCS20. Сите други оараметри остануваат со исти
вредности како и во основниот ороект (како такви се дадени оодолу). Секако дека со
зголемуваоето на времето на основно флотираое на оловните минерали ќе дојде до оромена
во кинетиката на флотираое, односно до оромена во количините на масите кои ооминуваат на
контролно флотираое и оонатаму во ороцесот на цинкова флотација. Пваа оромена не може
да се дефинира орецизно без детални лабораториски и оолуиндустриски исоитуваоа на
конкретната суровина. Но тоа би имало смисла само во услови кога, влезната суровина во
технолошкиот ороцес би имала константни вредности, оо основ на орисуството на корисните
минерали (галенит и сфалерит). Земајќи ги оредвид флуктуациите, во однос на количината на
вкуоен метал во влезната суровина, кои често можат да бидат и 2 – 3 % секакви обиди за
орецизираое на шемата на текот на масите би биле излишни
Application of High Performance Liquid Chromatography to the Analysis of Pesticide Residues in Apple Juice
The modern apple production involves the use of large amounts of pesticides that can be found in processed products such as apple juice. Harmful effects of pesticide residues on humans, especially children, are well known, hence the content of pesticide residues in fruit, vegetables and their juices should be controlled. This study presents an application of a new, relatively simple and reliable analytical method for qualitative and quantitative determination of three organophosphorus and one organonitrogen pesticide residues in apple juices. The analysis utilizes reversed-phase high-performance liquid chromatography (RP-HPLC) followed by UV diode array detection. Prior to HPLC analysis, a solid-phase extraction (SPE) was used for analytes concentration and sample clean-up. Specificity, selectivity, linearity, precision, accuracy and limit of quantification (LOQ) were examined to assess the validity of the developed method. The method had satisfactory values of multiple correlation coefficients for calibration curves (R2 ≥ 0.95
). The precision was evaluated for the retention times and peak areas, and the estimated values for relative standard deviations (RSD) were 0.05 % - 0.18 % and 0.09 % - 0.62 %, respectively, which indicated an excellent precision of the proposed method. Under the established conditions, the recovery of analytes was 93.80 % - 119.41 %, with relative standard deviations below 0.56 %. This method was successfully applied for determination of some organophosphorus and organonitrogen pesticide residues in apple juices which were taken from Macedonian markets. The achieved values for LOQs were low enough compared to the MRLs of the investigated pesticides in apple according to the Regulation (EC) No 396/2005. Detectable residues of the examined pesticides were not found in the analyzed samples