Croatian Geomagnetic Normal Reference Field of 2004.5

Predstavljeni su rezultati prve izmjere deklinacije, inklinacije i totalnog intenziteta, izvedene u ljeto 2004. godine na Hrvatskoj geomagnetskoj sekularnoj mreži. Opisani su mjerni postupci, korišteni instrumentarij te redukcija mjerenja na epohu 2004,5. Hrvatsko geomagnetsko normalno referentno polje za 2004,5 definirano je koeficijentima polinoma drugog reda po latitudi i longitudi. Model normalnog polja pokazao je znatne razlike u odnosu na globalni model DGRF. S pomoću Mokrovićevih podataka iz 1928. godine procijenjena je sekularna varijacija na teritoriju Hrvatske.The results of the first declination, inclination and total intensity survey of the Croatian Geomagnetic Repeat Stations Network that took place in the summer of 2004 are presented. The applied measurement procedures, the instruments used, as well as the reduction of measurements to the epoch of 2004.5 are described. The Croatian Normal Reference Field of the 2004.5 is represented by means of the coefficients of the second order polynomial in latitude and longitude. Normal field model showed a significant differences in respect to global DGRF. The secular variation of the Croatian territory was estimated with the help of Mokrović’s 1928. data

Geomagnetic survey on Sinjsko polje repeat station and data reduction using the onsite dIdD variometer

U sklopu hrvatsko-mađarskog projekta po prvi puta u Republici Hrvatskoj geomagnetska izmjera izvedena je upotrebom terenskog dIdD (delta Inklinacija / delta Deklinacija) variometra. S obzirom da su opažanja vektora geomagnetskog polja dobivena u referentnom okviru instrumenta, potrebno je odrediti kalibracijske parametre čime se omogućuje transformacija u geografski koordinatni sustav XYZ. Tri i pol dana trajanja izmjere na sekularnoj točki Sinjsko polje (SINP) otkrilo je vremensku promjenjivost gradijenata geomagnetskog polja. Iako su opažanja bila pod utjecajem doprinosa dodatnog magnetskog polja, određivanje mirne razine razlika geomagnetskog polja između sekularne točke SINP i referentnog opservatorija THY (Tihany) omogućilo je pouzdaniju redukciju. Usporedba rezultata različitih metoda redukcija ukazala je na poboljšanje geomagnetske izmjere korištenjem terenskog variometra.Within the Croatian-Hungarian project for the first time in the Republic of Croatia the repeat stations survey was carried out using an onsite dIdD (delta Declination / delta Inclination) variometer. Since the geomagnetic field vector observations are obtained in the instrument’s reference frame, the calibration parameters have to be determined enabling the transformation to the geographic coordinate system XYZ. Three and a half days long occupation of the Sinjsko polje (SINP) repeat station revealed the temporal variability of the geomagnetic field gradients. Although observations were affected by extra magnetic field contributions, the determination of the quiet-time level geomagnetic field differences between the SINP repeat station and THY (Tihany) reference observatory enabled a more reliable data reduction. The comparison of results of different data reduction methods pointed out the improvement of the geomagnetic survey with the onsite variometer

Presence of nitrates and nitrites in fresh cow milk from milk machines during winter and summer period in the city Zagreb and Zagreb County area

Introduction: The aim of the study was to determine the nitrites and nitrates content in fresh cow’s milk samples from milking machines, and to determine whether their amount is affected by the season of sampling (summer/winter). Methods: The methodology used was analytical transversal method at 2-time points. All milk samples were sampled at milk machines from the City of Zagreb and Zagreb County, during the summer and winter months in 2020. A total of 40 milk samples were sampled, with 20 samples in each monitored period (summer/winter). A high-performance liquid chromatography with a diode array detector was used to identify and quantify concentrations of the nitrate and the nitrite content. The results were processed using descriptive statistics and the statistics of differences. Results: The analysis determined the range of nitrate content from 1.28 mg/kg to 19.71 mg/kg and the range of nitrite content was from 0.49 mg/kg to 3.42 mg/kg in milk samples. The mean result of nitrates in fresh cow’s milk samples in the summer period was 9.12 mg/kg and in the winter period of 3.88 mg/kg. The mean value of nitrite in the summer was 1.23 mg/kg, while the mean value of nitrite in the winter period was 1.48 mg/kg. Conclusion: The research has shown that the nitrate and the nitrite levels in local fresh cow’s milk sampled in milk machines do not exceed the maximum allowable intake. The obtained results confirmed that the amounts of nitrates and nitrites in the milk samples differ significantly during the winter and summer periods and differences are depending on the location of the milk machine

Croatian Geomagnetic Repeat Stations Network

Prikazana je uspostava mreže primarnih sekularnih geomagnetskih točaka na teritoriju Republike Hrvatske. Točke za istraživanje sekularne varijacije projektirane su sukladno preporukama Coordination Committee for Common European Repeat Station Surveys, kriterijima International Association of Geomagnetism and Aeronomy – IAGA te iskustvima europskih zemalja. Konačne lokacije sekularnih točaka izabrane su evaluacijom kriterija na samom terenu. U tu svrhu razvijene su i testirane metode određivanja gradijenata totalnog intenziteta uključujući potrebnu programsku podršku. Iz ispitivanja različitih materijala uslijedio je izbor kamene stabilizacije. Točke mreže stabilizirane su ukopavanjem stabilizacije standardnim geodetskim postupcima. Status svake točke mreže dokumentiran je obrascima Položajnog opisa i Geomagnetskih parametara.The establishment of primary geomagnetic repeat stations on the territory of the Republic of Croatia was presented. Stations for secular variation study were designed in accordance to recommendations of the Coordination Committee for Common European Repeat Station Surveys, criteria of the International Association of Geomagnetism and Aeronomy - IAGA, as well as experiences of the European countries. Final locations of the repeat stations were determined by the field evaluation of the criteria. For that purpose, the total intensity gradients survey methods, along with required software, were developed. Following the testing of various materials, the rock monument was selected. The network points were setup by digging in the monument using standard geodetic procedures. The Status of the each network point was documented in Position Description and Geomagnetic Parameters forms

Provjera autentičnosti ekstrakta lista biljke Ginkgo biloba L. i proizvoda koji ga sadrže na hrvatskom tržištu putem analize količine i omjera ginkoflavonoglikozida (kvercetin, kempferol i izoramnetin) i terpenskih trilaktona u svrhu otkrivanja krivotvorenih pripravaka opasnih za zdravlje korisnika

Ginkgo biloba L. is the eldest plant growing on the Earth; preparations made of its leaves and seeds represent an integral part of the Chinese medicine for over a millennium. The plant species was first discovered by Linnaeus in 1771, its name thereby originating from the Latin words bis (two) and lobus (lobe), which duly illustrate the specific shape of its leaf. Contemporary Ginkgo biloba L. plant based pharmaceuticals mostly comprise extracts recovered from leaves harvested during fall, when the concentration of active components reaches its peak. Recent investigations have managed to establish the chemical composition of the plant leaf, together with the mechanisms underlying its beneficial effects on rheological profile of the blood and acceleration of its flow. High price of these preparations and their vast popularity have soon become an incentive for counterfeiting Ginkgo biloba L. extracts and the release of bogus drugs comprising cheaper extracts coming from other plants. Namely, modern Ginkgo biloba L.-based medicinal products and food supplements comprise extracts recovered from the plant leaf that get to be standardized according to its key pharmacological active components, most often flavone glycosides (represented in the share of 22%-27%) and terpene trilactones (represented in the share of 6%-7%). The flavonoids that predominate such preparations and are most relevant from the pharmacological standpoint are quercetin, kaempferol and isorhamnetin, their total amount and mutual ratios, thereby being an unquestionable indicator of the extract authenticity. Therefore, most of the analyses aiming at verifying the authenticity of a given Ginkgo biloba L.-based product boil down to the analysis of these parameters. Counterfeiting involves partial or full replacement of the Ginkgo biloba L. extract (GBE) with a cheaper plant extract of a similar composition, the latter occasionally being enriched with an additional amount of flavonoids, most often quercetin, not originating from the Ginkgo biloba L. plant. The aim of this study was to verify the authenticity and quality of Ginkgo biloba L.-based products circulating on the Croatian market. To that effect, 10 samples of products produced by various manufacturers were analyzed in a certified laboratory. The parameters based on which the authenticity of the preparations was assessed were the shares of aglycones of typical ginkgo flavone glycosides, that is to say, quercetin, kaempferol and isorhamnetin, and mutual ratios of the established quantities of quercetin to kaempferol as the key clues to unmasking Ginkgo extracts counterfeiting. The amount of ginkgo flavone glycosides was established using high performance liquid chromatography. The analysis proved 80% of the samples analyzed to be conformant to the label statements as regards the total amount of flavone glycosides and their mutual ratios. In 20% of the samples, the ratio of quercetin to kaempferol deviated from normal values; on top of that, the presence of the phytoestrogen genistein, one of the components typically comprised by the Sophora japonica L. plant, was also proven, documenting counterfeiting of the GBE and its replacement by the Sophora japonica L. extracts in the samples under consideration. Due to the untrue label statements descriptive of these products, the information on the presence of pharmacologically active genistein was neglected to be mentioned despite its unfavorable health impact that can be expected in some consumer groups. The results of this study indicated the frequency of counterfeiting the Ginkgo biloba L.-based products found on the Croatian market to be deemed substantial. Therefore, a more rigorous and more thorough control of these products and sanctioning of irresponsible manufacturers and distributers is proposed, so as to contribute to a higher market representation of high-quality products, as well as to avoid health risks and downsize the rate of their counterfeiting.Ginkgo biloba L. najstarija je biljka na zemlji, a pripravci od njegovih listova i sjemenaka dio su kineske medicine već više tisuća godina. Vrstu je 1771. godine otkrio Linnaeus, a ime je dobila od latinskih riječi bis, tj. dva i lobus zbog specifičnog oblika lista. Današnji farmaceutski oblici biljke Ginkgo biloba L. sadrže uglavnom ekstrakte iz listova ubranih ujesen kada je najveća koncentracija aktivnih komponenata. Suvremenim istraživanjima određen je kemijski sastav njegovog lista, a utvrđeni su i mehanizmi njegovog pozitivnog djelovanja na reološka svojstva krvi i ubrzanje njezinog protoka. Visoka cijena i velika popularnost ubrzo su postali poticaj za krivotvorenje ekstrakta biljke Ginkgo biloba L. jeftinijim ekstraktima drugih biljaka. Naime, suvremeni medicinski proizvodi i dodaci prehrani na osnovi biljke Ginkgo biloba L. sadrže ekstrakte njegovog lista koji se standardiziraju prema njegovim ključnim farmakološki aktivnim sastavnicama; najčešće je to 22%-27% flavonoid glikozida i 6%-7% terpenskih trilaktona. Kvercetin, kempferol i izoramnetin su dominantni i farmakološki najvažniji flavonoidi, a njihova ukupna količina i međusobni omjeri nedvojben su pokazatelj autentičnosti ekstrakta. Stoga se i većina analiza za utvrđivanje ispravnosti proizvoda koji sadrže biljku Ginkgo biloba L. temelji na analizi ovih parametara. Krivotvorenja podrazumijevaju djelomičnu ili potpunu zamjenu ektrakta Ginkgo biloba L. nekim jeftinijim biljnim ekstraktom sličnog sastava uz eventualno obogaćivanje dodatnom količinom flavonoida, najčešće kvercetina, koji ne potječu od biljke Ginkgo biloba L. Svrha ovoga rada bila je provjeriti autentičnost i kakvoću pripravaka Ginkgo biloba L. na hrvatskom tržištu. Analizirano je ukupno 10 uzoraka različitih proizvođača. Kao pokazatelji njihove ispravnosti određivani su udjeli aglikona karakterističnih ginkoflavonoglikozida: kvercetin, kempferol i izoramnetin te omjeri nađenih količina kvercetina i kempferola kao ključni pokazatelji krivotvorenja ginkgo-ekstrakta. Količina ginkoflavonoglikozida određena je metodom tekućinske kromatografije visoke djelotvornosti. Analizom je utvrđeno da 80% uzoraka odgovara navodima deklaracije u pogledu ukupne količine flavonoglikozida kao i u pogledu njihovog međusobnog omjera. U 20% uzoraka omjer kvercetina i kempferola odstupao je od uobičajenih vrijednosti, a dokazano je i prisustvo fitoestrogena genisteina, jedne od karakterističnih sastavnica biljke Sophora japonica L., čijim ekstraktom je krivotvoren ginkgo-ekstrakt u analiziranim uzorcima. Zbog neistinite deklaracije na proizvodima koji su sadržavali ove ekstrakte izostalo je i obvezno upozorenje o prisutnosti farmakološki aktivnog genisteina koji može izazvati neželjene zdravstvene posljedice kod pojedinih skupina potrošača. Rezultati ovoga rada ukazuju na značajnu pojavnost krivotvorenja proizvoda biljke Ginkgo biloba L. na hrvatskom tržištu te se zbog toga predlaže njihova temeljitija kontrola kao i sankcioniranje neodgovornih proizvođača i trgovaca, čime bi se doprinijelo većem udjelu kvalitetnijih proizvoda i izbjegli zdravstveni rizici te smanjila pojavnost prijevare

Utjecaj različitih površinskih obrada litij-disilikatne keramike ojačane cirkonijevim dioksidom na smičnu čvrstoću samoadherirajućega smolastoga cementa

Aim: To analyze the influence of different surface pretreatments of zirconium dioxide reinforced lithium disilicate ceramics on the shear bond strength of self-adhesive resin cement. Materials and methods: Eighty-four zirconium reinforced lithium disilicate disc Vita suprinity (Vita Zahnfabrick, Bad Säckingen, Germany) 14x12x2 mm specimens were fabricated according to the manufacturer’s recommendations. The specimens were embedded in acrylic resin blocks and randomly divided in seven groups (n=12/each) accorrding to the treatment: Group 1- 10% hydrofluoric acid; Group 2- silane; Group 3- hydrofluoric and silane; Group 4- sandblasting with silane; Group 5- Er: YAG laser+ silane; Group 6- Nd: YAG laser + silane; and the control group, in which the specimens were not treated. Round shape composite discs (Filtek Bulk fill, 3M ESPE, St.Paul, Minnesota, USA) with 3.5 mm diameter, were made for shear bond strength testing, and then cemented to the ceramic sample surface using composite cement (RelyX U200 Automix, 3M ESPE, Neuss, Germany). After cementing the composite disc on the sample, the samples were subjected to shear bond strength test of 10 N with a “stress rate” of 1 MPa / s. To determine the nature of the fracture (adhesive, cohesive or adhesivecohesive), the broken samples were examined under a stereomicroscope. The ANOVA test and the Tukey test were used to compare the values of the bond strength characteristics between different types of materials. All tests were performed with a significance level of α = 0.05. Results: There was a significant difference in the shear bond strength of self-adhesive cement to dental lithium-disilicate ceramics reinforced with zirconium dioxide after different preparation protocols (p<0, 05). The treatment of lithium disilicate ceramics reinforced with zirconium dioxide by silanization, sandblasting + silanization, Nd: YAG + silanization resulted in significantly higher bond strength compared to the control group. There was statistically higher bond strength of self-adhesive cement after pretreatment of lithium disilicate ceramics Nd: YAG + silanization compared to Er: YAG + silanization (p<0.05). Adhesive fracture dominated in the control group, sandblasting + silanization group, and in the laser groups, while mixed fracture dominated in other groups. Conclusion: Under the limitations of this study, the Nd:YAG irradiation with silanization could be used as pretreatment for providing greater shear bond strength of self-adhesive resin cement to zirconium reinforced lithium disilicate.Cilj: Analizirati utjecaj različitih površinskih obrada litij-disilikatne keramike ojačane cirkonijevim dioksidom na veznu čvrstoću samoadherirajućega smolastoga cementa. Materijali i metode: Osamdeset i četiri litij-disilikatna uzorka diska Vita suprinity (Vita Zahnfabrick, Bad Säckingen, Njemačka) ojačana cirkonijevim dioksidom, veličine 14 x 12 x 2 mm, proizvedena su prema preporukama proizvođača. Uzorci su inkorporirani u akrilatne blokove i podijeljeni prema vrsti površinskog tretmana u sedam skupina (n = 12 / svaka): skupina 1. – 10-postotna fluorovodična kiselina; skupina 2. – silanizacija; skupina 3. – fluorovodična kiselina i silanizacija; skupina 4. – pjeskarenje i silanizacija; skupina 5. – Er: YAG laser + silanizacija; skupina 6. – Nd: YAG laser + silanizacija; kontrolna skupina u kojoj uzorci nisu obrađivani. Za testiranje smične čvrstoće napravljeni su diskovi od kompozita (Filtek Bulk fill, 3M ESPE, St.Paul, Minnesota, SAD) okruglog oblika promjera 3,5 mm, te su pričvršćeni na površinu keramičkog uzorka kompozitnim cementom (RelyX U200 Automix, 3M ESPE, Neuss, Njemačka). Nakon cementiranja kompozitnog diska na uzorak, uzorci su podvrgnuti testu snage smične sile od 10 N uz stress rate od 1 MPa/s. Kako bi se ustanovila priroda loma (adhezivni, kohezivni ili adhezivno/kohezivni), slomljeni uzorci pregledani su pod stereomikroskopom. Za usporedbu vrijednosti obilježja snage vezivanja između različitih vrsta materijala korišteni su ANOVA i Tukeyev test. Svim testovima razina značajnosti bila je α = 0,05. Rezultati: Značajna je razlika u veznoj čvrstoći samoadherirajućega cementa na dentalnu litij-disilikatnu keramiku ojačanu cirkonijevim dioksidom nakon različitih protokola pripreme (p < 0,05). Zabilježena je značajno veća snaga vezivanja nakon tretmana litij-disilikatne keramike ojačane cirkonijevim dioksidom postupkom silanizacije, pjeskarenja + silanizacije i Nd:YAG laserom + silanizacija u odnosu prema kontrolnoj skupini. Postoji statistički značajno veća vezna čvrstoća samoadherirajućega cementa nakon predtretmana litij-disilikatne keramike laserom Nd:YAG + silanizacijom u usporedbi s laserom Er:YAG + silanizacijom (p < 0,05). U kontrolnoj skupini i u skupini pjeskarenje + silanizacija te u skupinama s laserom prevladava adhezivni lom, a u ostalima mješoviti. Zaključak: Uzimajući u obzir ograničenja ovog istraživanja, Nd: Yag lasersko zračenje u kombinaciji sa silanizacijom moglo bi se koristiti kao predtretman u svrhu osiguravanja bolje čvrstoće vezivanja samoadherirajućega smolastoga cementa i litij-disilikatne keramike ojačane cirkonijevim dioksidom

Determiniranje teških metala u različitim vrstama riba uzorkovanih na hrvatskim tržnicama i mogući utjecaj na zdravlje

The purpose of this study was to determine and to compare the amount of heavy metals in the meat of white (N = 39) and blue (N = 35) sea fish, considering the spring (N = 38) and fall (N = 36) catch period to study the possible type and seasonal differences especially in Hg concentrations in fish, and to estimate if the amounts registered can have a harmful effect on consumer health. The fish were chosen as an indicator of eco-system contamination with mercury and other heavy metals. The amount of heavy metals, lead (Pb) and cadmium (Cd), in both groups was lower than the Highest Permissible Amounts regulated by law in Croatia and the European Union. Mercury (Hg) exceeded the maximum allowed value in just a number of samples 3/74 (0.04%), while it is relevant for arsenic (As) to be present in almost any sample, although it has simultaneously not been regulated by law. The statistically significant value of arsenic exists in blue fish during the spring period, and the amount of mercury is higher in white fish compared to blue fish. Also a statistically significant difference in mercury levels was recorded during fall compared to spring,. Given the dietary habits and frequent fish consumption in Croatia, there is no risk of harmful health effects.Cilj ovoga rada bio je odrediti i usporediti količinu teških metala u 74 uzorka bijele (N = 39) i plave ribe (N = 35), uzorkovanih u proljetnom (N = 38) i jesenskom razdoblju (N = 36), kako bi se istražila moguća razlika u koncentracijama teških metala, posebice žive, ovisno o sezoni ulova ili tipu ribe i procijenilo mogu li determinirane količine imati štetnih utjecaja na zdravlje potrošača. Riba je izabrana, budući da je ona indikator zagađenja teškim metalima u eko sustavu. Količina teških metala, olova (Pb) i kadmija (Cd), u obje grupe uzoraka, bila je niža od maksimalnih dopuštenih koncentracija prema hrvatskih i europskim zakonima. Količina žive (Hg) bila je više od maksimalnih dopuštenih koncentracija u vrlo malom broju uzoraka 3/74 (0,04%). Međutim, u uzrocima su zabilježene relevantne količine arsena (As), iako količine arsena nisu regulirane hrvatskim propisima. Multivarijatna statistička obrada (neparametrijski Mann-Whitney U test) pokazala je statistički značajne razlike u količini arsena u proljetnom razdoblju u odnosu na jesensko razdoblje, kao što je i izmjerena količina žive statistički značajno bila viša u bijeloj u odnosu na plavu ribu, te ona izmjerena u jesenskom razdoblju u odnosu na proljetno. Uzevši, međutim, u obzir potrošačke navike i učestalost konzumacije ribe u Hrvatskoj, izmjerene koncentracije nisu povezane s rizikom štetnih posljedica na zdravlje potrošača

Nitrate in leafy green vegetables and estimated intake

Background: Vegetarian diets are rich in vegetables. Green leafy vegetables are foods that contain considerable amounts of nitrate, which can have both positive and negative effects on the human body. Their potential carcinogenicity and toxicity have been proven, particularly after the reduction of nitrate to nitrite itself or just serving as a reactant with amines and/or amides in the formation of N-nitroso compounds -N-nitrosamines and other nitrogen compounds which may have high levels of nitrate. The aim of this study was to determine whether there is a significant difference, considering the location and seasonal sampling period, in the level of nitrate in certain types of green vegetables, all in order to be able to assess their intake, and possible impact on human health, especially knowing that exposure to nitrate can be potentially higher for vegetarian population group.Materials and Methods: For this purpose, the sampling of 200 different leafy green vegetables was conducted, all of which could be found in free sale in the Republic of Croatia. The sampling was conducted during two seasonal periods - the spring and autumn period. In the springtime, lettuce (sem), spinach (pinacho), kale (kale), chard (mangel) and cabbage (brassica) were sampled, and in autumn lettuce, spinach, kale, chard and arugula. Samples were analyzed using high performance liquid chromatography (HPLC) with UV detection.Results: The results from the spring sampling phase were in the range of 603 mg/kg for cabbage - 972 mg/kg for chard, and for autumn phase of 1.024 mg/kg for chard to 4.354 mg/kg for the arugula. The results showed that there were significant differences (p &lt;0.05) for most of the samples analyzed, considering the sampling locations and time period.Conclusion: The results indicate that the analyzed vegetables contain significant amounts of nitrate in their composition, which represents relatively significant, but still acceptable intake into the human body.Keywords: leafy green vegetables, nitrate, HPLC, season period, daily intak

Monitoring the Change of Chemical Parameters of Honey Dependent on the Storage Method

Med je po definiciji namirnica kojoj se ništa ne smije dodavati niti oduzimati kako bi zadržala svoja izvorna karakteristična svojstva. Podaci Food Fraud networka govore kako je riječ o hrani koja podliježe sve češćim prevarama potrošača, odnosno krivotvorenju. Med je specifičnog kemijskog i nutritivnog sastava koji mu daju status visokovrijedne hrane. Taj sastav, osim krivotvorenjem sastojaka, može se ugroziti i njegovim neadekvatnim skladištenjem ili pogrešnom manipulacijom tijekom prerade i prodaje. Cilj je ovoga projekta pratiti promjene osnovnih parametara kvalitete meda kao što su kiselost, elektrovodljivost, aktivnost dijastaze i količina hidroksimetilfurfurala (HMF), koji se mijenjaju s duljinom skladištenja, temperaturom i izloženošću meda Sunčevoj svjetlosti. Istraživanjem je utvrđeno da različiti uvjeti skladištenja meda povezani s promjenom temperaturnog režima imaju utjecaj na promjenu kvalitete meda. Ukupno je analizirano osam uzoraka meda (pet uzoraka meda bagrema i tri uzorka cvjetnog meda), a dobiveni rezultati prikazuju prosječne vrijednosti svih analiziranih uzoraka. Najveće promjene utvrđene su kod dijastaze i HMF-a. Med je skladišten na temperaturi od –20 °C, 0 °C, 20 °C te na temperaturi od 40 °C i 60 °C. Rezultati ukazuju da izlaganje meda višim temperaturama utječe na smanjenje aktivnosti dijastaze ispod 8DN. Jednako tako, rezultati ukazuju da vrijednosti HMF-a pri visokim temperaturama rastu i ako je izloženost meda visokim temperaturama dulja, vrijednosti HMF-a prelaze maksimalne vrijednosti (40mg/kg). Stoga je od velike važnosti da se pri distribuciji i skladištenju meda vodi računa o izloženosti meda utjecaju direktne svjetlosti i temperature okoliša u kojem se med skladišti kako bi se sačuvale prirodne vrijednosti meda. Potrebno je radi zaštite potrošača med skladištiti izvan dohvata Sunčeve svjetlosti i visokih temperatura, a sve u cilju zaštite zdravlja ljudi.Honey is, by definition, a product to which nothing must be added in order to retain its original properties. Data from Food Froud Network indicates that honey is food which is more and more submitted to chemical counterfeiting by manufacturers and consumer fraud. Honey is of specific chemical and nutritional structure, which gives it its status as food of high value. Besides chemical counterfeit, the sole structure of honey can be jeopardized by leaving it in glass containers too long, since it expiration date is two years after packaging. The purpose of this project is to monitor the honey quality parameters, like acidity, electrical conductivity, diastasis activity and amount of hydroxymethylfurfural (HMF). These parameters alter with length of time the honey is being kept in a container, as well as temperature and sunlight exposure. The study has found different conditions of honey storage, related to the evaluation of the temperature regime, have an impact in honey’s quality change. In total, eight samples of honey were analized (five samples of acacia honey, three samples of flower honey), the results show the average values of all analized samples. Major changes were found in diastasis activity and HMF, which can affect the health benefits of honey. Honey was stored at the temperature of -20 °C, 0 °C, 20 °C, 40 °C and 60 °C. The results show that exposure of honey to higher temperatures impacts upon reduction of diastasis activity below 8 DN. Likewise, the results show that the amount of Hydroxymethylfurfural (HMF) at high temperatures increases, and the longer the exposure of honey is to higher temperatures, the amount of HMF exceeds the maximum values (40 mg/kg). Therefore, it is of great importance that during the distribution and storage of honey, special attention is paid on sunlight and high temperature exposure, in order for natural values of honey to be preserved. It is required, in order to protect consumers and their health, for honey to be stored away from sunlight and high temperatures

Cereals and milled products as a good source of magnesium in everyday diet

Žitarice predstavljaju najrasprostranjeniju i najvažniju kulturu za prehranu ljudi. Važne su i kao sirovina u prehrambenoj industriji te čine osnovu piramide prehrane. Mlinski proizvodi također predstavljaju osnovne prehrambene proizvode. Glavni su mlinski proizvodi prekrupa, krupica i brašno. Magnezij je mineral koji je iznimno važan element u ljudskom organizmu. Zauzima četvrto mjesto po zastupljenosti kationa u organizmu te je drugi najčešći u stanicama. Ima važnu ulogu za katalitičku aktivnost više od 300 enzima u enzimatskim sustavima. Najvažniji je za pravilan rad srca te kao regulator fosfora i kalcija u kostima. Cilj je ovog rada utvrditi količinu magnezija u odabranim žitaricama i mlinskim proizvodima te prikazati zdravstvenu dobrobit magnezija. Tijekom analize sastava žitarica i mlinskih proizvoda analizirano je sveukupno 28 uzoraka. Od toga je bilo pet uzoraka kukuruza u zrnu, sedam uzoraka pšenice, 11 uzoraka pšeničnog brašna, brašno od integralne heljde bez glutena, zobena kaša, prosena kaša, kaša zobi, ječma i pira te kaša riže, kukuruza i heljde. Analiza je provedena na Nastavnom zavodu za javno zdravstvo „Dr. Andrija Štampar”. Magnezij je nakon digestije s nitratnom kiselinom i vodikovim peroksidom u mikrovalnoj pećnici određen induktivno spregnutom plazmom s masenom spektrometrijom (ICP-MS). Količine magnezija u žitaricama iznosile su od 81,92 mg / 100 g do 145,21 mg / 100 g za pšenicu te od 111,68 mg / 100 g do 145,21 mg / 100 g za kukuruz. Prosječna vrijednost magnezija iznosila je 105,81 mg / 100 g za uzorke pšenice te 133,72 mg / 100 g za uzorke kukuruza u zrnu. Količina magnezija utvrđena u pšeničnom brašnu kretala se u rasponu od 23,17 mg / 100 g do 60,41 mg / 100 g, dok je srednja vrijednost magnezija iznosila 34,56 mg / 100 g. Količina magnezija u brašnu od integralne heljde bez glutena iznosila je 226,32 mg / 100 g. Utvrđena količina magnezija u zobenoj kaši, prosenoj kaši, kaši zobi, ječma i pira te kaši riže, kukuruza i heljde kretala se u rasponu od 76,77 mg / 100 g do 153,61 mg / 100 g. Srednja vrijednost magnezija za uzorke kaše iznosila je 122,98 mg / 100 g.Cereals represent the most prevailing and important culture for human consumption. They are also important as a raw material in the food industry and form the basis of the food pyramid. Milled products also represent basic food products. The main milled products are groats, semolina and flour. Magnesium is a mineral that is an extremely important element in the human body. It ranks fourth in the representation of cations in the body and is the second most common in cells. It plays an important role for the catalytic activity of more than 300 enzymes in the enzymatic systems. It is most important for proper heart function and as a regulator of phosphorus and calcium in the bones. The aim of this paper is to determine the amount of magnesium in selected cereals and milled products and to present the health benefits of magnesium. A total of twenty eight samples were analysed during the analysis of the composition of cereals and milled products. Of these, there were 5 samples of corn beans, 7 wheat samples, 11 samples of wheat flour, gluten-free whole buckwheat flour, oatmeal, millet porridge, porridge oats, barley and spelt, and rice, corn and buckwheat mash. The analysis was carried out at the Andrija Stampar Teaching Institute of Public Health. After microwave digestion with nitrate acid and hydrogen peroxide, magnesium was determined by inductively coupled plasma with mass spectrometry (ICP-MS). The amounts of magnesium in cereals ranged from 81.92 mg/100 g to 145.21 mg/100 g for wheat, and from 111.68 mg/100 g to 145.21 mg/100 g for corn. The average magnesium value was 105.81 mg/100 g for wheat samples and 133.72 mg/100 g for grain corn samples. The amount of magnesium found in wheat flour ranged from 23.17 mg/100 g to 60.41 mg/100 g, while the mean magnesium value was 34.56 mg/100 g. The amount of magnesium in the flour from gluten-free wholegrain buckwheat was 226.32 mg/100 g. The determined amount of magnesium in oatmeal, millet porridge, porridge oats, barley and spelt and porridges of rice, corn and buckwheat ranged from 76.77 mg/100 g to 153.61 mg/100 g. The mean magnesium value for porridge samples was 122.98 mg/100 g