Прегледај по Аутор "Grujić, Radoslav"
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- СтавкаAnalysis of myofibrillar and sarcoplasmic proteins in pork meat by capillary gel electrophoresis(Kemerevo State University, Russia, 2018) Grujić, Radoslav; Savanović, DanicaMyofibrillar and sarcoplasmic proteins were extracted from pork meat (M. Longissimus dorsi) and then separated by capillary gel electrophoresis (CGE). Migration time and peak areas of individual protein molecules in the electropherogram were analysed. The electropherograms obtained after the separation of myofibrillar proteins contained 53 well-separated peaks, of which the following were identified: thymosin, myosin light chain-3 (MLC-3), myosin light chain-2 (MLC-2), troponin C, troponin I, myosin light chain-1 (MLC-1), tropomyosin 1, tropomyosin 2, troponin T, actin, desmin, troponin, C protein, and myosin heavy chain (MHC). The relative concentration of the identified myofibrillar proteins was 74.5%. Of the 56 separated sarcoplasmic proteins the following were identified: myoglobin, myokinase, triosephosphate isomerase, phosphoglycerate mutase, lactate dehydrogenase, glyceraldehyde phosphate dehydrogenase, aldolase, creatine kinase, enolase, phosphoglucose isomerase, pyruvate kinase, phosphoglucomutase, and phosphorylase b. The relative concentration of the identified sarcoplasmic proteins was 83.6% of all sarcoplasmic proteins extracted from the pork meat.
- СтавкаBiopolymers as Food Packaging Materials(Springer, 2017) Grujić, Radoslav; Vujadinović, Dragan; Savanović, DanicaThis review examines the recent trends, current technology and future challenges in applications of biopolymers as food packaging materials, together with potential solutions, as well as discussing the major safety concerns regarding food packaging materials produced from sustainable and renewable resources. As food contact materials, biopolymers are increasingly being utilized as alternatives to conventional plastics obtained from oil derivatives. This review covers most of the available polymers, focusing on the general principles of their production, properties, and analysis of the possibilities for potential use in food packaging. The use of biopolymers brings new opportunities, not only from the point of replacing conventional polymers and other materials that are widely used in food packaging (glass, paper, metals, etc.), but also in the way it opens up a whole new level of properties and characteristics. Bio-based resources are the base source for production of biopolymers in food application, while in practice, bioresource content may be different. Biopolymers can be produced by microorganisms through fermentative processes of different bioresources [e.g., polyhydroxyalkanoates (PHAs)] and biomass may be produced directly from different kind of plant (starch, cellulose, etc.). In the context of growing environmental and safety concerns, biopolymers have gained increased attention, related to concerns about conventional plastics traditionally produced from fossil fuel.
- СтавкаCHROMATOGRAPHIC SEPARATION OF GLUTENIN WITH HIGH MOLECULAR WEIGHT FROM WHEAT FLOUR(KEY, 2020) Gojković Cvjetković, Vesna; Grujić, Radoslav; Marjanović-Balaban, ŽeljkaGlutenins with high molecular weight (HMW glutenins) are one of the glutenin's fractions. They play a key role in the formation of the gluten elasticity property and contribute to the formation of large glutenin polymers. The aim of this study was to investigate the effect of solvent type and column temperature on the chromatographic separation of HMW glutenins from wheat flour. For HMW glutenins extraction, 50% (v/v) ethanol, 1-propanol and isopropanol was used to which Tris-HCl (0.05 mol/L, Ph = 7.5), urea (2 mol/L) and dithioerythritol (1%) were added. The high performance liquid chromatography (HPLC) method (HPLC Agilent Technologies 1260 Infinity, Zorbax 300SB-C3 column) was used for protein separation at a column temperature 40, 45 and 50 0C. Absorbance measurements were performed at 210 nm and 280 nm. The effect of the solvents tested on the separation of HMW glutenins was shown by determining the number of observed peaks (proteins) on the chromatogram and calculating the relative concentration of HMW in the total number of glutenins from wheat flour (RC). After the extraction of glutenin proteins with 50% (v/v) ethanol, the highest number of proteins at 210 nm was observed when the column temperature was 45 0C and 50 0C (Xsr = 6.17 and RC1 = 17.76% and RC2 = 27.07%) and the lowest number at a column temperature of 40 0C (Xsr = 4, RC = 13.43%). By extraction with 50% (v/v) 1-propanol, the highest number of proteins was observed at column temperatures of 40 0C and 45 0C (Xsr = 5.17 and RC1 = 28.22% and RC2 = 31.70%, respectively) and the lowest number at 50 0C (Xsr = 4.67, RC = 34.68%) and by extraction with 50% (v/v) isopropanol the highest number of proteins was observed at a column temperature of 50 0C (Xsr = 7.17, RC = 23.61%) and the lowest number at 45 0C (Xsr = 5.83, RC = 10.67%). After the extraction of glutenin proteins with 50% (v/v) ethanol and detection at a wavelength of 280 nm, the highest number of proteins was observed at a column temperature of 45 0C (Xsr = 8.33, RC = 36.49%), and the lowest at 40 0C (Xsr = 5.50, RC = 32.57%). In the case of protein extraction with 50% (v/v) 1-propanol, the highest number of HMW glutenins was observed at 40 0C (Xsr = 7.83, RC = 61.62%) and the lowest at 50 0C (Xsr = 4.67, RC = 39.18%). When extraction was performed with 50% (v/v) isopropanol, the highest number of proteins was observed at a column temperature of 45 °C (Xsr = 7.33, RC = 21.66%), and the lowest number at a column temperature of 40 0C and 50 0C (Xsr = 7.00, RC1 = 28.64%, RC2 = 34.22%). Based on the obtained results it can be seen that the highest number of proteins was observed with 50% (v/v) ethanol (Xsr = 8.33)
- СтавкаColor change of orange and carrot juice blend treated by non-thermal atmospheric plasma(Wiley, 2017) Vukić, Milan; Vujadinović, Dragan; Ivanović, Marko; Gojković, Vesna; Grujić, RadoslavDielectric barrier discharge (DBD) atmospheric plasma treatment is an innovative non-thermal food processing technology. There is an abundant body of research on the effectiveness in inactivation of foodborne pathogens on fresh fruit and vegetable produce with atmospheric air DBD plasma. However, studies that disclose plasma interactions with fruit or vegetable juices are scarce in number to the knowledge of the author. Color changes of orange and carrot juice blend due to atmospheric air DBD plasma treatment have been examined to estimate the extent of juice changes after treatments at varying durations of 5 s,15 s, and 30 s. Results indicate potentiality of cloud loss reduction, while treatments can cause minor degradation of color attributes. However, browning of treated samples was not observed. The influence of this new non-thermal treatment on measured properties of orange and carrot juice blend shows promising results which need to be further confirmed and established.
- СтавкаGliadin proteins from wheat flour the optimal determination conditions by ELISA(2021) Marjanović-Balaban, Željka; Gojković Cvjetković, Vesna; Grujić, RadoslavIntroduction. The number of people with celiac disease is rapidly increasing. Gluten, is one of the most common food allergens, consists of two fractions: gliadins and glutenins. The research objective was to determine the optimal conditions for estimating gliadins by using enzyme-linked immunosorbent assay (ELISA). Study objects and methods. The experiment involved wheat flour samples (0.10, 0.20, 0.25, 0.50, and 1.0 g) suspended in different solvents (ethanol, methanol, 1-propanol, and isopropanol) of different concentrations (40, 50, 60, 70, 80, and 90% v/v). The samples were diluted with Tris buffer in ratios of 1:50, 1:100, 1:150, and 1:200. The gliadin test was performed using a Gliadin/Gluten Biotech commercial ELISA kit (Immunolab). Results and discussion. The optimal conditions for determining gliadin proteins that provided the highest gliadin concentration were: solvent – 70% v/v ethanol, extract:Tris buffer ratio – 1:50, and sample weight – 1.0 g. Conclusion. The obtained results can be of great importance to determine gliadin/gluten concentrations in food products by rapid analysis methods.
- СтавкаKNOWLEDGE OF FOOD QUALITY AND ADDITIVES AND ITS IMPACT ON FOOD PREFERENCE(Publishing House of the Poznań University of Life Sciences, Poland, 2013) Grujić, Slavica; Grujić, Radoslav; Petrović, Đorđe; Gajić, JelenaBackground. There are not enough published investigations concerning knowledge on food quality and preference of highly educated young consumers from Bosnia and Herzegovina. The present research was aimed at survey of young consumers’ knowledge on food quality and food additives and its impact on food preference. Material and methods. Respondents’ answers were analysed grouped regarding: (1) education, on subjects with knowledge on food quality and additives (A-group) and average consumer representatives (B-group); (2) female and male gender. The questionnaire consists of (a) questions with personal data; questions referred to the importance of individual factors for consumers’ food choice, related to: (b) fundamental knowledge on food quality and food additives; (c) nutrition and desire to consume food that contains additives; (d) knowledge on monosodium glutamate and desire to consume food containing monosodium glutamate. Results. Results indicated a statistically signifi cant difference between A-group and B-group, and between female and male subjects, on fundamental knowledge on food quality and additives, but there was no difference in habits regarding nutrition and desire to consume food that contains additives. Respondents in A-group signifi cantly more avoid products containing monosodium glutamate comparing to B-group, but there was no difference between female and male subjects preference. Conclusions. This research has shown that students from A-group had more knowledge and awareness in choices of food they prefer to consume, than students from B-group. It is recommended to take actions on young consumers’ education as contribution to protecting of the health, safety, economic and legal interests of consumers and society.
- СтавкаKNOWLEDGE OF FOOD QUALITY AND ADDITIVES AND ITS IMPACT ON FOOD PREFERENCE(Publishing House of the Poznań University of Life Sciences, Poland, 2013) Grujić, Slavica; Grujić, Radoslav; Petrović, Đorđe; Gajić, JelenaBackground. There are not enough published investigations concerning knowledge on food quality and preference of highly educated young consumers from Bosnia and Herzegovina. The present research was aimed at survey of young consumers’ knowledge on food quality and food additives and its impact on food preference. Material and methods. Respondents’ answers were analysed grouped regarding: (1) education, on subjects with knowledge on food quality and additives (A-group) and average consumer representatives (B-group); (2) female and male gender. The questionnaire consists of (a) questions with personal data; questions referred to the importance of individual factors for consumers’ food choice, related to: (b) fundamental knowledge on food quality and food additives; (c) nutrition and desire to consume food that contains additives; (d) knowledge on monosodium glutamate and desire to consume food containing monosodium glutamate. Results. Results indicated a statistically signifi cant difference between A-group and B-group, and between female and male subjects, on fundamental knowledge on food quality and additives, but there was no difference in habits regarding nutrition and desire to consume food that contains additives. Respondents in A-group signifi cantly more avoid products containing monosodium glutamate comparing to B-group, but there was no difference between female and male subjects preference. Conclusions. This research has shown that students from A-group had more knowledge and awareness in choices of food they prefer to consume, than students from B-group. It is recommended to take actions on young consumers’ education as contribution to protecting of the health, safety, economic and legal interests of consumers and society.
- СтавкаMINERAL COMPOSITION OF TRADITIONAL SHEEP MEAT PRODUCTS IN DEPENDENCE ON THE THERMAL TREATMENT(KEY, 2019) Rekanović, Sebila; Grujić, Radoslav; Vučić, Goran; Hodžić, ElvisaSheep meat products are traditionally present in the diet of the population in the Balkan countries. It presentsan important source of protein, fat, energy and a large number of well-absorbable mineral substances (iron, calcium, zinc and magnesium). Loss of the mineral matter is possible during the heat treatment of meat, which is a key stage in the process of making traditional sheep meat products. The loss depends on the applied thermal treatment. Manufacturers try to adapt the traditional technology of making sheep meat products to modern industrial conditions and to ensure production throughout the whole year. The aim of this study was a comparative analysis of sheep meat mineral composition produced in modern industrial conditions and ones produced by traditional technology, with the focus being given to the conditions of heat treatment and meat drying. Four experimental groups of boiled sheep meat samples with temperature variations 55 - 75 0C, boiling time 15 - 30 minutes and relative humidity 74 - 86%, and four groups of dried sheep meat with temperature variations 14 - 18 0C, drying time 24 h and relative humidity 85 - 88% were included in this study. Inductively coupled plasma mass spectrometry (ICP-MS) with a microwave-assisted digestion treatment was used for determination of mineral matter in all meat samples. The results show increased value of all elements in the boiled sheep meat in relation to their content in dried products. Also, the content of mineral substances in samples of dried and boiled sheep meat was increased in relation to fresh samples, depending on the applied parameters. Main component analysis showed that all properties observed were present with high value in one of the first five major components. The most important properties in the first major component, which carry 88.47% of the total variability of the experiment, are Na, K, Mg, Cd, Pb and Se. Mineral matter content was higher in samples of boiled sheep meat than in dried ones. The reduction of smoking time and temperature enhancement had the greatest influence on the increasement of the mineral matter content in boiled and dried sheep meat samples.
- СтавкаSENSORY EVALUATION AS TOOL IN QUALITY IMPROVEMENT OF BOILED CHICKEN SAUSAGE(2012) Savanović, Danica; Grujić, Slavica; Grujić, Radoslav; Savanović, JovoFood product quality and stability during storage is very important for the successful manufacturing. It is known that different factors during processing have impact on quality characteristics of final product. The aim of the study was to investigate influence of selected food additives with antioxidant and stabilising functional characteristics on quality of finely comminuted boiled chicken sausages “parizer” type, during storage. Samples were produced in industrial conditions, five experimental model samples with selected additive blends added separately to each: (a) 0.04% GUARDIAN Rosemary Extract 08 (Natural rosemary extract, E471, E472a, E1520); (b) 0.10% (based on the fat content) GRINDOX 539 Antioxidant (E304, E306, E322, rapeseed oil); (c) 0.30% GRINDSTED Carrageenan CC 310 (E407, E410); (d) 0.30% GRINDSTED MEATLINE 345 A Emulsifier and Stabiliser System (E401, E516, E470a, E450); (e) 0.30% GRINDSTED MEATLINE 333 Stabiliser System (Carob germ flour, E466) and (f) control sample, according to the producer’s specification. The samples had adequate chemical composition. Sensory evaluation of selected sensory characteristics was done 7 days and 35 days after samples production: (1) by the descriptive sensory analysis - scoring method, and (2) by discriminatory sensory analysis - ranking method, after assessment and comparison of the overall quality of sausages model samples. The results of the sensory analysis indicated differences between model samples dependent on added additives. On the basis of descriptive sensory evaluation results, it was found that the best quality of compared had sausage sample produced with addition 0.30% GRINDSTED MEATLINE 345 A Emulsifier and Stabiliser System (E401, E516, E470a, E450). Discriminatory sensory analysis – ranking confirmed that finding.
- СтавкаSeparation of gliadins from wheat flour by capillary gel electrophoresis: optimal conditions(Kemerovo State University, 2020) Grujić, Radoslav; Gojković Cvjetković, Vesna; Marjanović-Balaban, ŽeljkaIntroduction. Gliadin proteins are one of the gluten fractions. They are soluble in alcoholic solution and divided into four groups (α + β, γ, ω1.2, and ω5-gliadins). In this paper gliadins were extracted from wheat flour, and optimal conditions for their separation were determined. Study objects and methods. The separation was performed by capillary gel electrophoresis on Agilent apparatus, CE 7100 (a capillary with an inner diameter of 50 μm, a total length of 33 cm, and an effective length of 23.50 cm). In order to determine the optimal conditions, different solvent concentrations (50, 60, and 70% ethanol), capillary temperatures (20, 25, 30, 35, and 40°C), and electrode voltages (–14.5, –16.5, –17.5 and –18.5 kV) were applied. Migration time and relative concentration of each protein molecules within gliadin fractions in the electrophoregram were analysed using Agilent ChemStation Software. Results and discussion. The optimal conditions for gliadin separation were: solvent 70% (v/v) ethanol, capillary temperature of 25°C, and electrode voltage of –16.5 kV. Under these conditions, the total proteins were indetified as Xav = 23.50, including α + β gliadin fraction (Xav = 7.50 and relative concentration RC = 28.29%), γ-gliadins (Xav = 5.00, RC = 26.66%), ω1.2-gliadins (Xav = 4.33, RC = 14.93%), and ω5-gliadins (Xav = 6.67, RC = 30.98%). Conclusion. The results of the research can be of fundamental importance in the study of gluten proteins and the influence of technological procedures on their change and the possibility of reducing the allergic effect of gluten during processing.
- СтавкаTHE EFFECT OF THE DURATION OF SEPARATION AND WAVELENGTHS OF ABSORBANCE’S MEASUREMENT ON THE EFFECTIVENESS OF ELECTROPHORETIC SEPARATION OF GLIADINS BY GCE(2022) Gojković Cvjetković, Vesna; Grujić, Radoslav; Marjanović-Balaban, ŽeljkaGliadins are one of the gluten components which are present in most wheat products. Based on their mobility in acidic polyacrylamide gel electrophoresis (A-PAGE), gliadins are divided into α+β, γ, ω1.2, and ω5 classes. Gliadins are allergenic proteins which play a key role in celiac disease pathogenesis. Considering that the number of people with celiac disease is increasing, the aim of this study was to examine how different duration of analysis (30, 35 and 40 minutes) and wavelengths (200, 210 and 230 nm) effect the gliadin separation effectiveness by glassy carbon electrode (GCE). We examined the effect of duration of capillary gel electrophoresis (GCE) separation (30, 35 and 40 minutes) and measurement of absorbance at different wavelengths (200, 210, and 230 nm) on the effectiveness of electrophoretic separation by capillary gel electrophoresis, with the aim of faster identification and quantification of gliadin proteins. Separation of gliadin proteins by GCE was performed on an Agilent, CE 7100 apparatus. SDS-MW analysis kit, PA 800 plus (2015 Beckman Coulter, USA) was used. Based on the obtained results the optimal duration of GCE separation was 30 minutes, because the number of observed proteins is the highest and the effectiveness of electrophoretic separation is the best (Xav = 23.50). A wavelength of 200 nm proved to be the best wavelength. By measuring the absorbance at this wavelength, the total number of observed proteins is Xav=18.33. In this study a duration of 30 minutes and a wavelength of 200 nm proved to be optimal. As the duration of analysis increases, the number of proteins decreases
- СтавкаTHE INFLUENCE OF EXTRACTION CONDITIONS AND CHROMATOGRAPHIC SEPARATION ON THE ABILITY OF IDENTIFYING GLIADINS FROM THE WHEAT FLOUR(Consulting and Training Centre, KEY, 2019) Gojković, Vesna; Marjanović-Balaban, Željka; Grujić, Radoslav; Vujadinović, Dragan; Vukić, MilanCereal proteins play an important role in the humans’ and animals’ diet, due to their nutritional composition and functional properties in food production. One of these proteins is gluten. It contains protein components that are present as monomers and interconnected by disulfide bonding polymers. Based on their solubility in an aqueous alcohol, gluten proteins are divided into soluble gliadins and insoluble glutenins. Apart from the beneficial nutritional composition and importance in food production, gluten also causes adverse health effects in susceptible individuals, such as celiac disease. In this paper, gliadin proteins have been analyzed in wheat flour by high-pressure liquid chromatography of reversed phases (RP-HPLC). The influence of different concentrations of ethanol (30%, 40% and 50%) and column temperature (40 C, 45 C and 50 C) was investigated to achieve better chromatographic separation and identification of gliadin proteins. The chromatographic separation of gliadin proteins was carried out on the column Zorbax 300 SB-C3 (Agilent) and the Agilent Technologies 1260 Infinity HPLC apparatus has been used. After extraction gliadin proteins with 30% (v/v) ethanol, the number of identified proteins was 20, after extraction with 40% (v/v) ethanol was 21 and with 50% (v/v) ethanol was 24, at a temperature of 40 C. By increasing the column temperature (45 oC and 50 oC), the number of identified proteins after extraction with 30% ethanol was 17 and 20, after extraction with 40% ethanol was 25 and 24, and after extraction with 50% ethanol was 26 and 24. Based on the obtained results, the largest number of gliadin proteins was identified by extraction with 50% ethanol and at a column temperature of 45 C. By increasing the column temperature to 50 oC, the number of identified proteins decreases.