34 research outputs found

    Nanocomplexes of polymers and surfactant in drug delivery

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    Istraženi su nanokompleksi anionskoga biopolimera, karagena i kationske površinski aktivne tvari za primjenu u terapijskim sustavima. Struktura i veličina kompleksa od nano- do mikrodimenzija ovise o koncentraciji i omjeru koncentracija pojedinih komponenata, te linearnoj gustoći naboja na lancu karagena. Faktori o kojima ovisi kompleksiranje jesu elektrostatska i hidrofobna međudjelovanja, te konformacija karagena. Porastom koncentracije karagena, unutar-makromolekulski kompleksi prelaze u među-makromolekulske, koji se postupno reorganiziraju u uređenije strukture, divovske vezikule, talog - dodecilamonijev karagenat i gel. Nastajanje divovskih vezikula i strukturna svojstva netopljivih kompleksa i urušenoga gela pokazuju daje lamelno uređenje stuktuma značajka kompleksa karagena i kationske površinski akivne tvari.Nanocomplexes formed from anionic biopolymers, carrageenans, and cationic surfactant have been investigated for their applicability in drug delivery. Stucture and complex size from nano- to microdimension strongly depends on concentration and concentration ratio of both components and linear charge density on carrageenan chains. Factors governing the complex formation are electrostatic and hydrophobic interactions as well as conformation of the carrageenan chains. With increasing carrageenan concentration, the intra-macromolecular complexes change to inter-macromolecular, which subsequently reorganize into bettei ordered structures, giant vesicles, precipitate - dodecylammonium carrageenate and gels. Formation of giant vesicles and structural properties of insoluble complexes and collapsed gels revealed lamellar ordering as an important feature of the carrageenan and an oppositely charged surfactant complexes

    Utjecaj crvene protuinsektne fotoselektivne mreže na generativne i vegetativne karakteristike jabuke \u27Granny smith\u27

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    Anti-insect photoselective nets present a new technology that combines light manipulation and pest protection in orchards. In this study, the effect of the anti-insect photoselective red net on the generative and vegetative traits was studied in an apple orchard near the city of Zadar, Croatia. \u27Granny Smith\u27 apples were grown on M9 rootstock and raised as slender spindles. The experiment consisted of two treatments: the trees covered with the red photoselective anti-insect nets (AGRITECH S. r. l., Eboli, Italy; mesh size of 2.4 × 4.8 mm) and uncovered trees as control. Yield, percentage of fruit with diameter >70 mm and fruit mass were not significantly different between treatments. L* color value was higher on fruit skin grown under the red net, and there was no significant difference in other color values (a*, b*, C* and h°). Soluble solids concentration (SSC) and total flavonoid content were significantly lower in fruit grown under red net than in control, and there was no significant difference in titratable acidity (TA), SSC/TA ratio, starch degradation and Streif maturity index. Red net proved to be effective against fruit red blush development (undesirable trait for \u27Granny Smith\u27 apple) and sunburn damage occurrence.Protuinsektne fotoselektivne mreže predstavljaju novu tehnologiju koja istovremeno kombinira manipulaciju svjetlom i zaštitu od štetnika. U voćnjaku jabuka pokraj Zadra (Hrvatska) istraživan je utjecaj crvene protuinsektne fotoselektivne mreže na generativne i vegetativne parametre jabuke \u27Granny Smith\u27. Jabuke su uzgajane na M9 podlozi te su imale uzgojni oblik vretenastoga grma. Istraživanje se sastojalo od dvaju tretmana: stabla prekrivena crvenom protuinsektnom fotoselektivnom mrežom (AGRITECH S. r. l., Eboli, Italija; veličina okca od 2.4 × 4.8 mm) i nepokrivena stabla kao kontrola. Prirod, udio plodova s promjerom >70 mm i masa plodova nisu se signifikantno razlikovali između tretmana. Jabuke uzgajane ispod crvene mreže imale su signifikantno veću L* vrijednost parametra boje kožice, dok za ostale parametre boje nije zabilježena signifikantna razlika (a*, b*, C* i h°). Sadržaj topljive suhe tvari (TST) i ukupni sadržaj flavonoida bio je signifikantno niži u jabukama uzgajanima ispod crvene mreže, dok nije zabilježen signifikantan utjecaj crvene mreže na titracijsku kiselost (TA), TST / TA, stupanj razgradnje škroba i indeks zrelosti (Streif). Primjena crvene mreže pokazala se vrlo djelotvornom u smanjenju pojavnosti dopunskoga crvenila (koje je kod jabuke \u27Granny Smith\u27 nepoželjno svojstvo) i ožegotina od sunca na plodovima

    Prediction of Chemical Composition from Semi-natural Grassland by NIR Spectroscopy

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    The objective of this research was to examine three techniques for prediction of the chemical composition by NIR spectroscopy (1100 – 2500 nm) from semi-natural grassland: modified partial least squares (MPLS) regression; partial least square (PLS) regression and principal component regression (PCR). A spectral data for a total of 150 samples originated from seminatural grassland were used. Standard errors of calibration (SEC) for crude proteins (CP) were 6.52, 4.87 and 6.94 for MPLS, PLS and PCR, while standard errors of cross validation (SECV) were 8.16, 6.13 and 7.56 respectively. SEC for organic matter (OM) were 7.69, 7.61 and 7.37 for MPLS, PLS and PCR, while SECV were 8.08, 8.27 and 7.57 respectively. Higher SEC and SECV were reported for neutral detergent fibre (NDF) and acid detergent fibre (ADF) content than reported for CP and OM content. Hyperspectral analysis by PLS resulted in the highest accuracy for the estimation of crude protein, organic matter and neutral detergent fibre and acid detergent fibre, while MPLS was the best in predicting acid detergent fibre. The greatest accuracy in this research was achieved for CP, then NDF, OM, and finally ADF content. Prediction for NDF, OM, and especially ADF content should be improved in the future by involving specific semi-natural grassland samples

    Release of Trichoderma viride Spores from Microcapsules Simultaneously Loaded with Chemical and Biological Agents

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    Recent studies of bioactive agents, simultaneous encapsulation in chitosan/alginate microcapsules revealed that encapsulation in the same compartment does not inhibit activity either of Trichoderma viride spores nor copper cations. The objective of this work was to investigate the influence of formulation variables (concentration of copper cations, chitosan layer and microcapsule size) on T. viride spores release. Results showed that the increase in copper cation concentration promoted, but the increase in microcapsule size and presence of the chitosan layer on microcapsule surface reduced T. viride spores release. Fitting to simple Korsmeyer–Peppas empirical model elucidated the underlying mechanism of release. Fickian diffusion controlled release from microcapsules without chitosan layer and smaller microcapsules with chitosan layer, whereas anomalous diffusion mechanism (a combination of the diffusion and erosion mechanisms) was found to be the rate-controlling mechanism from larger microcapsules with chitosan layer. The investigation showed that proper selection of formulation variables helps in designing microcapsules with the desirable release of T. viride for plant protection and nutrition

    POTENTIAL FOR APPLICATION OF FEED ADDITIVES ENCAPSULATION TECHNOLOGY IN ANIMAL NUTRITION

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    Zahtjevi za većom proizvodnjom i potražnja potrošača za zdravijom hranom potaknuli su posljednjih godina intenzivna istraživanja alternativnih promotora rasta životinja. Trendovi istraživanja su orijentirani na razvoj novih proizvoda obogaćenih dodacima stočnoj hrani s ciljem poboljšanja zdravlja životinja i boljeg prirasta. Mnogi od tih spojeva su nestabilni u prisutnosti svjetla, zraka, vode ili visokih temperatura te ih je potrebno zaštiti tijekom procesiranja, skladištenja i primjene. Inkapsulacijom u mikročestice dodaci stočnoj hrani se štite od štetnih vanjskih utjecaja, a ne umanjuju im se stabilnost i funkcionalnost. Tehnologija mikroinkapsulacije se koristi za zaštitu dodataka i poboljšanje biodostupnosti kontroliranom i ciljanom isporukom u probavni trakt. Posebno je pogodna za dodavanje u hranidbi preživača, jer se pravilnim izborom materijala mikročestice omogućava oslobađanje dodataka u tankom crijevu, a ne u buragu. Uz pravilno korištenje, formulacije mikročestica su učinkovit alat u hranidbi životinja koji isporučuje hranjive sastojke i/ili lijekove na određeno mjesto željenom brzinom. U radu su sažeta laboratorijska istraživanja primjene tehnologije mikroinkapsulacije dodataka stočnoj hrani u hranidbi preživača i monogastričnih životinja. Brojni rezultati primjene inkapsuliranih bioaktivnih spojeva pokazali su pozitivne učinke na zdravlje životinja, povećanje produktivnosti bez štetnih učinaka na konačni proizvod i zaštitu okoliša.Demands for higher production and consumer demand for healthier food have encouraged intensive research for alternative animal growth promoters in recent years. Research trends are focused on the development of new products enriched with feed additives to improve animal health and enhancing production. Many of these compounds are unstable in the presence of light, air, water, or high temperatures and need to be protected during processing, storage, and application. By encapsulatied in microparticles, feed additives are protected from harmful external influences, and their stability and functionality are not diminished. Microencapsulation technology is used to protect payload and improve bioavailability by controlled and targeted delivery to the digestive tract. It is particularly suitable for the addition of feed additives in ruminant’s nutrition, because the correct choice of microparticle material allows the release of the feed additives in the small intestine, and not in the rumen. With proper use, microparticle formulations are an effective tool in animal nutrition that delivers nutrients and/or drugs to a specific site at the desired rate. The paper summarizes laboratory studies on the application of microencapsulation technology in feeding ruminants and monogastric animals. Numerous results of the application of encapsulated feed additives have shown a positive effect on animal health, increased productivity without negative effects on the final product, and environmental protection

    Effect of Yellow and Stop Drosophila Normal Anti-insect Photoselective Nets on Vegetative, Generative and Bioactive Traits of Peach (cv. Suncrest)

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    The effect of anti-insect photoselective yellow (mesh size of 2.4x4.8 mm) and Stop Drosophila Normal (mesh size of 0.90x1 mm) nets on the generative and vegetative traits of peach (cv. Suncrest) was studied at an orchard near the city of Čakovec, Croatia. Netting significantly affected some vegetative parameters (leaf surface, leaf length and leaf shape index) but there was no significant effect on productivity parameters (yield, yield efficiency, fruit mass and share of decayed fruit). Regarding fruit colouration application of nets significantly affected b* and C* background and L*, b*, C* and h° additional colour parameters. Majority of inner fruit quality parameters (fruit firmness, titratable acidity and total soluble solids / titratable acidity ratio) as well as of bioactive compounds (total polyphenolic content, antioxidant activity, anthocyanin content and share of alkali-soluble pectin) was also under significant effect of netting. Since yellow net only slightly reduced peach fruit quality (compared to control) it can be recommended for application as an anti-insect net. However, Stop Drosophila Normal net more notably reduced quality parameters (especially additional fruit colour) and hence should be used only when other control strategies show to be ineffective

    Formiranje aromatskih spojeva u siru

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    Cheese is one of the most popular dairy products, with an incredible diversity of varieties, shapes, textures, and flavours available locally and globally. Extensive research has been conducted on the aroma compounds present in cheese. Numerous studies have identified over 3000 volatile and non-volatile components in cheese. The volatile components, which consist of fatty acids, alcohols, aldehydes, esters, ketones, lactones, sulphur compounds, amines, and other flavour-active compounds, are primarily responsible for the aromatic characteristics (aroma) of cheese. This paper thoroughly discusses the biochemistry behind the formation of significant aroma compounds that affect overall cheese quality and sensory characteristics. It provides an extensive review of the most recent methodologies for the extraction and determination of aroma compounds in cheese.Sir je jedan od najznačajnijih mliječnih proizvoda s velikom raznolikošću vrsta, oblika, teksture, okusa i arome dostupnih lokalno i globalno. Provedene su brojne studije o spojevima koji sudjeluju u formiranju arome i okusa te je identificirano više od 3000 hlapljivih i nehlapljivih spojeva u siru. Hlapljive komponente koje se sastoje od masnih kiselina, alkohola, aldehida, estera, ketona, laktona, sumpornih spojeva, amina i drugih aktivnih tvari zaslužne su za stvaranje aromatskih karakteristika u siru. U radu su detaljno objašnjeni biokemijski procesi tijekom formiranja značajnih aromatskih spojeva koji utječu na ukupnu kvalitetu i senzorne karakteristike sira te je pružen pregled najnovijih metodologija za ekstrakciju i određivanje hlapljivih spojeva u siru
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