<p>Termalne osobine svinjskog mesa (Longissimus dorsi) osmotski dehidratisanog u melasi &scaron;ećerne repe i svežeg svinjskog mesa praćene su metodama termalne analize: Diferencijalnom skenirajućom kalorimetrijom (DSC), termogravimetrijskom analizom (TGA), modulovanom diferencijalnom skenirajućom kalorimetrijom (MDSC). Dobijeni rezultati pokazuju postojanje novonastale proteinske osnove osmotski dehidratisanog svinjskog mesa koji je posledica smanjenja količine vode i interakcije komponenti melase s proteinima mesa. Nađeno je da osmotskom dehidratacijom dolazi do promene i pregrupisavanja preostale slobodne vode u dva oblika, &scaron;to ukazuje na mehaničko strukturne promene u interfibrilarnoj mreži i pojednostavljivanje strukture proteinske osnove. Definisani su nastali strukturni nivoi proteinske osnove: strukturni nivo vode vezane na protein tj. postojanje proteinske strukture i posle osmotske dehidratacije -strukturni nivo I; strukturni nivo mreže sa ujednačeno manjim porama tj. nivo energetski jače vezane imobilizirane -strukturni nivo II; strukturni nivo mreže sa ujednačeno većim porama tj. nivo energetski slabije vezane imobilizirane -strukturni nivo III.<br />Ispitivanjem termalnih osobina uzoraka osmotski dehidratisanog mesa sa smanjenom vlagom ( ispod 20%) nađeno je postojanje staklastog prelaza po&scaron;to je najveća količina vode vezana za čvrsti matriks. Definisani su optimalni uslovi rehidratacije osmotski dehidratisanog svinjskog mesa, te su određene Pelegove konstante rehidratacije. Nađeno je postojanje nativnih struktura proteina u osmotski dehidtiranom mesu i određeni su kinetički parametri denaturacije (Ea, kb) svežeg i osmotski dehidriranog mesa. Određen je sadržaj makroelemenata osmotski su&scaron;enog svinjskog mesa. Radi obja&scaron;njenja složenosti interakcija proteina mesa i sastojaka osmotskog rastvora melase koje se odvijaju pri dehidrataciji, kao model sistem poslužila je interakcija proteina albumina goveđeg seruma (BSA) s jonima nekih makroelemenata prisutnih u melasi.</p> / <p>Thermal properties of pork meat (Longissimus dorsi) osmotically dehydrated in sugar beet molasses and fresh pork were followed by the methods of thermal analysis: Differential Scanning Calorimertry (DSC), Thermogravimetric Analysis (TGA), Modulated Differential Scanning Calorimetry (MDSC). The results indicate the existence of newly formed protein matrix as a consequence of osmotic dehydration of pork meat: reducing the amount of water and the interaction of the components of molasses and meat proteins. It has been found that changes were induced by the process of osmotic dehydration, and rearrangeement of the remaining free water in two forms. Also as a consequence of the osmotic dehydration, structural changes in the interfibrilar network and simplifying of the original structure of the meat protein matrix were occurred. A structural levels of protein matrix were defined: as structural level of the water bound to the protein, meaning the existence of protein structure and after osmotic dehydration Structural level I; a structural level with uniformly small pores in the network of formed protein matrix: energy level of more tightly immobilized water &ndash;Structural level II; and structural level of network with uniformly larger pores, energy level of lower bound immobilized water - Structural level III. By characterization of the thermal properties of the samples of osmotically dehydrated meat with reduced moisture (below 20%) the glass transition was found, as most of the water bound to a solid matrix.The optimal conditions for rehydration of dehydrated pork meat were defined, and Peleg&lsquo;s rehydration constants were obtained. It was found that the existence of the native structure of the protein in the osmotically dehydrated meat, and the kinetic parameters of protein denaturation (Ea, kb) of fresh and dehydrated meat were obtained. The content of macroelements in the osmotically dehydrated, fresh pork meat and in the sugar beet molasses were obtained. In order to explain the complexity of the interaction of meat proteins with the components of the osmotic solution -molasses that occur in the dehydration process, the model-system of the protein bovine serum albumin (BSA) interaction with the ions were implied to present simple interaction of some major elements with a protein matrix followed by DSC and ITC .</p>

No description available.

<p>Valorizacija permeata kao sporednog proizvoda industrije mleka je od izuzetnog ekolo&scaron;kog, ekonomskog i tehnolo&scaron;kog značaja.<br />Cilj doktorske disertacije je razvoj tehnolo&scaron;kog procesa prerade permeata, kao sporednog proizvoda dobijenog nakon ultrafiltracije mleka tokom proizvodnje feta sira i svežeg (&bdquo;mladog&ldquo;) sira. Ispitana je mogućnost enzimske hidrolize laktoze u permeatu kori&scaron;ćenjem enzima &beta;-galaktozidaze izolovanog iz Kluyveromyces lactis u koncentraciji 0,1, 0,3 i 0,5 g/100g na temperaturama 20&ordm;, 30&ordm; i 40 &ordm;C. Praćene su promene sadržaja laktoze, D&ndash;galaktoze i D&ndash;glukoze u vremenskim intervalima tokom 60 minuta. Posebna faza istraživanja obuhvatila je matematičko modelovanje i kinetiku procesa hidrolize laktoze u permeatu pod dejstvom &beta; &ndash;galaktozidaze i primenu hidrolizovanog permeata u proizvodnji mlečnih napitaka po odabranoj formulaciji. Predložen je tehnolo&scaron;ki proces proizvodnje napitka na bazi hidrolizovanog permeata sa dodatkom voćnih baza. Utvrđeni su parametri kvaliteta i trajnosti napitaka tokom 60 dana skladi&scaron;tenja.<br />Na temperaturi 40&deg;C dodatkom enzima &beta; -galaktozidaze u koncentraciji 0,1g/100g za 60 minuta postiže se 100% stepen hidrolize prisutne laktoze u permeatu. Sa većom koncentracijom enzima, 0,3 g/100g odnosno 0,5g/100g, na istoj temperaturi, isti efekat se postiže za 20 minuta.<br />Ispitivanjem kinetike hidrolize laktoze potvrđena je kinetika prvog reda. Generalno posmatrano visoki koeficijenti determinacije pokazuju dobro poklapanje eksperimentalnih rezultata i matematičkog modela reakcije prvog reda. Vrednosti se kreću od 0,974 (temperatura 20&deg;C) do preko 0,990 (na temperaturama 30&deg;C i 40&deg;C) pri koncentraciji enzima 0,1g/100g.<br />Proizvedeni napici od hidrolizovanog permeata su delaktozirani i ne sadrže mlečnu mast. Od ukupnih &scaron;ećera u svim napicima vi&scaron;e od 50% čini glukoza: 50,16% - napitak &scaron;umsko voće, 50,42% - napitak pomorandža/&scaron;argarepa, 54,65% - napitak multivitamin, odnosno 55,13% - napitak crveno voće.<br />Najveći sadržaj vitamina C nakon proizvodnje imao je napitak sa dodatkom voćne baze multivitamin 0,3972 mg/100g, zatim &scaron;umsko voće 0,2887 mg/100g i pomo-randža/&scaron;argarepa 0,1999 mg/100g.<br />Najveću vrednost antioksidativne aktivnosti nakon proizvodnje pokazali su uzorci napitka sa multivitaminom i &scaron;umskim voćem. Tokom perioda skladi&scaron;tenja dolazi do smanjenja DPPH vrednosti. Najmanji pad je u napitku sa pomorandžom / &scaron;argarepom (smanjenje za 17%), a najveći u napitku sa &scaron;umskim voćem (za 39%). Analizirani uzorci sadrže ukupnih polifenola u intervalu od 47,84 do 120,38 mg GAE/l u zavisnosti od vrste napitka, odnosno dodatih voćnih baza.<br />Generalno može se zaključiti da se prime-njenim tehnolo&scaron;kim procesom dobijaju napici stabilnog fizičko-hemijskog sastava tokom 60 dana skladi&scaron;tenja, visoke nutritivne i niske energetske vrednosti.</p> / <p>Valuation of the permeate as a by-product of the dairy industry is of great ecological, economic and technological importance.<br />The aim of the PhD thesis is the development of the technological process of refining permeate, as a by-product obtained after ultrafiltration of milk during the production of feta cheese and fresh cheese. The possibility of enzymatic hydrolysis of the lactose in the permeate using the enzyme &beta;-galactosidase isolated from Kluyveromyces lactis in a concentration of 0.1, 0.3 and 0.5 g / 100 g at a temperature of 20&deg;, 30&deg; and 40&deg; C was examined. Changes in the content of lactose, D-galactose and D-glucose at intervals of 60 minutes were monitored. A special stage of the research included mathematical modeling and kinetics of lactose hydrolysis in the permeate under the influence of &beta;-galactosidase and application of hydrolyzed permeate in the production of dairy products under the selected formulation. A technological process of producing a beverage on the basis of hydrolyzed permeate with the addition of fruit bases was suggested. Quality and durability parameters were determined for drinks during the 60 days of storage.<br />Addition of the enzyme &beta;-galactosidase at a concentration of 0.1 g / 100 g for 60 minutes at a temperature of 40 &deg; C a 100% degree of hydrolysis of lactose is achieved, present in the permeate. With a higher concentration of enzyme, 0.3 g / 100 g or 0.5 g / 100g, at the same temperature, the same effect can be achieved in 20 minutes.<br />By examining the kinetics of lactose hydrolysis the first order kinetics was confirmed. Generally high coefficients of determination show good correspondence between the experimental results and the mathematical model of the first order reaction. Values range from 0.974 (at a temperature of 20&deg; C) up to over 0.990 (at temperatures 30&deg; C and 40&deg; C) at a an enzyme concentration of 0.1g / 100g.<br />Beverages produced from hydrolyzed permeate are lactose-free and fat-free products. More than half of the total sugar content in all beverages consists of glucose: 50.16%-forest fruit beverage, 50.42%-beverage orange/carrot, 54.65% beverage multivitamin and 55.13% - beverage red fruit.<br />The highest vitamin C content after production was in a beverage with the addition of fruit base multivitamin (0.3972 mg/100g), followed by forest fruit (0.2887 mg/100g) and orange/carrot (0.1999 mg/100g).<br />Beverage samples with multivitamin and forest fruits showed the highest value of antioxidant activity after production. During the storage period there is a reduction of DPPH values. The smallest decrease was in the beverage with orange/carrot (decreased 17%), and the biggest in the beverage with forest fruit (39%). The content of polyphenols in analyzed samples ranges from 47.84 to 120.38 mg GAE/L depending on the type of beverage and added fruit base.<br />Overall it can be concluded that the applied technological process gives beverages of stable physical and chemical content during the 60 days of storage, of high nutritional value and low energy.</p>

<p>U okviru ove doktorske disertacije ispitani su i utvrđeni optimalni uslovi za proces lju&scaron;tenja semena suncokreta visokooleinskog tipa, kao sirovine za proizvodnju ulja. Sprovedena istraživanja su dala podatke o optimalnim vrednostima sadržaja vlage u semenu i pritiska vazduha u lju&scaron;tilici na osnovu kojih je utvrđen model za lju&scaron;tenje semena. Sprovedenim istraživanjima obuhvaćeno je i ispitivanje uticaja promenljivih tehnolo&scaron;kih parametara, sadržaja ljuske u opsegu od 0 do 20% i sadržaja nečistoća u opsegu od 0 do 10% na sastav i kvalitet hladno presovanih ulja i pogače, prinos ulja, oksidativnu stabilnost, senzorski kvalitet i boju hladno presovanih ulja semena suncokreta visokooleinskog tipa.<br />Dobijeni rezultati su obrađeni primenom savremenih klasifikacionih (klaster analiza i analiza glavnih kompomenata) i regresionih hemometrijskih metoda i postavljeni hemometrijski modeli čija bi primena doprinela proizvodnji hladno presovanog ulja vrhunskog kvaliteta i visoke oksidativne stabilnosti. Utvrđeno je da su definisani modeli statistički validni i da se mogu primeniti za optimizaciju tehnolo&scaron;kih parametara u proizvodnji hladno presovanog ulja semena suncokreta visokooleinskog tipa. Validnost postavljenih modela, odnosno kvalitet dobijenih korelacija su procenjeni na osnovu parametara unakrsne validacije.<br />Maksimalna efektivnost lju&scaron;tenja semena suncokreta visokooleinskog tipa može se postići pri optimalnim uslovima tj. sadržaju vlage u semenu 6,0% i pritisku vazduha u lju&scaron;tilici 800 kPa. Hladno presovano ulje semena suncokreta visokooleinskog tipa se, u pogledu sastava i kvaliteta ulja i pogače, prinosa ulja, oksidativne stabilnosti, senzorskog kvaliteta i boje ulja, može proizvoditi od semena koje sadrži 10-20% ljuske i 0-5% nečistoća.</p> / <p>In this dissertation the optimal conditions for the dehulling process of high-oleic sunflower seeds, as raw material for oil production, were tested and determined. The conducted studies provided data for the optimal values of moisture content in the seed and the air pressure in the seed dehulling machine, what presented the base for determination of the dehulling model. Also, conducted studies examine the effect of variable technological parameters, such as content of hull (ranging from 0 to 20%) and the impurities content (ranging from 0 to 10%) on the composition and quality of oil and cake, oil yield, oxidative stability, sensory quality and colour of cold pressed high-oleic sunflower oil.<br />The obtained results were analyzed by modern classification (cluster analysis and principal component analysis) and regression chemometrics methods, and chemometric models whose implementation could contribute to the production of cold pressed oil of high quality and high oxidative stability were set. It was found that the defined mathematical models are statistically valid and that they could be used to optimize the technological parameters of production of cold pressed high-oleic sunflower oil. The validity of the set models, that is the quality of obtained correlations, were estimated based on the parameters of cross-validation.<br />The maximum effectiveness of high-oleic sunflower seeds dehulling can be achieved under optimal conditions, i.e. when the moisture content in seed is 6,0% and when the air pressure in seed dehulling machine is 800 kPa. Regarding composition and quality of the oil and cake, oil yield, oxidative stability, sensory quality and color, cold pressed high-oleic sunflower oil could be produced from seed containing 10-20% hull and 0-5% impurities.</p>

No description available.

<p>U okviru doktorske disertacije ispitan je nutritivni kvalitet mleka magarice balkanske rase tokom laktacije. Prosečna suva materija mleka magarice balkanske rase iznosi 9,26%. Sadržaj proteina tokom laktacije kreće se od 1,40% do 1,92%. Prosečan sadržaj mlečne masti je 0,61%, a sadržaj laktoze iznosi 6,50%. Sadržaj analiziranih minerala: Ca, Na, K, Mg, P i Zn se povećava tokom laktacije i maksimalna vrednost utvrđena je 170. dana. Primenom kapilarne elektroforeze definisan je profil proteina mleka magarice balkanske rase. Identifikovane su sledeće proteinske frakcije: &alpha;s1-kazein, &alpha;s2-kazein, &beta;-kazein (A, F), &alpha;-laktalbumin (A, C), &beta;-laktoglobulin, lizozim, laktoferin, serum albumin i imunoglobulin čiji sadržaj opada tokom perioda laktacije. Sadržaj &alpha;-laktalbumina se kreće od 3090 mg/l do 1990 mg/l, a lizozima varira od 1040 mg/l do 2970 mg/l. Navedene frakcije proteina su najzastupljenije u mleku magarice balkanske rase. Laktoferin i imunoglobulin su frakcije sa najmanjim udelom u mleku magarice balkanske rase. Kori&scaron;ćenjem gasne hromatografije/masene spektrometrije utvrđen je sastav masnih kiselina mleka. Udeo esencijalne linolne kiseline (C18:2 n6) kreće se u opsegu od 7,08%, do 9,69%, a udeo &alpha;-linoleinske kiseline (C18:3 n3) varira od 5,85% do 7,83%.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Sastav mleka magarice balkanske rase kompariran je sa nutritivnim karakteristikama humanog mleka tokom 40. i 90. dana laktacije. Utvrđene su značajne razlike u sadržaju proteina mleka, mlečne masti i minerala. Odnos kazeina i proteina surutke kreće se od 0,68 do 0,75 u mleku magarice, dok u humanom mleku varira od 0,59 do 0,70. Udeo -linoleinske kiseline (C18:3 n3) je oko 2,5 puta veći u mleku magarice u odnosu na humano mleko.<br />Generalno se može zaključiti da mleko magarice balkanske rase ima specifične nutritivne karakteristike koje variraju u zavisnosti od sastava hrane za životinje i analiziranog perioda laktacije.</p> / <p>Nutritional quality of Balkan donkey milk during lactation was investigated within this thesis. The mean content of dry matter, fat and lactose in the Balkan donkey milk was 9.26%, 0.61% and 6.50%, respectively. Protein content during lactation period ranged from 1.40% to 1.92%. Content of the analyzed minerals: Ca, Na, K, Mg, Zn and P increased during the lactation period and reached their maximum value at 170th day. The protein profile of Balkans donkey milk was defined by application of capillary electrophoresis when the following protein fractions: &alpha;s1-kazein, &alpha;s2-kazein, &beta;-kazein (A, F), &alpha;-laktalbumin (A, C), &beta;-laktoglobulin, lysozyme, lactoferrin, serum albumins and immunoglobulins, whose content decreases during lactation period,were identified. &alpha;-lactalbumin contents ranged from 3090 mg/l to 1990 mg/ and lysozyme varies between 1040 mg/l to 2970 mg/l. These two protein fractions were the most abundant in the Balkan donkey milk, while lactoferrin and immunoglobulin were at least represented. The fatty acid composition of Balkan donkey milk was determined using gas chromatography/mass spectrometry. The share of the essential linoleic (C18: 2 n6) and &alpha;&nbsp;- linolenic (C18: 3 n3) acid rangred from 7.08 % to 9.69% and from 5.85 % to 7.83 %.</p><p>Nutritional quality of Balkan donkey milk has been compared with the nutritional quality of human milk during the 40th and 90th day of lactation. Significant differences in the protein content of milk, fat and minerals were found. The ratio of casein and whey protein ranged from 0.68 to 0.75 in the Balkan donkey milk, while in human milk this value varies from 0.59 to 0.70. The share of &alpha;-linolenic acid (C18:3 n3) is around 2.5 times higher in donkey than in human milk.<br />The main conclusion is that Balkan donkey milk has specific and unique nutritional quality which depend on the feed composition and on the analyzed period of lactation.</p>

No description available.

No description available.

No description available.

No description available.