The study examined the influence of ultrasound-assisted extraction and solid-liquid extraction wi... more The study examined the influence of ultrasound-assisted extraction and solid-liquid extraction with 80% of aqueous ethanol solution on the total phenolics, total flavonoids and total colour change of extracts from different varieties of figs (Bjelica, Termenjača, Crnica, Bružetka bijela and Šaraguja). The total phenolic content was determined by using Folin Ciocalteau assay. The content of total flavonoids was measured spectrophotometrically by using the aluminium chloride colourimetric assay. Colour changes were obtained by chromameter CR-400 (Minolta) in L*a*b * colour model. Ultrasound-assisted extrac-tion showed highest total phenolic content (up to 13.72%) and total flavonoid content (up to 18.55%) compared to classic solid-liquid extraction. According to given results total colour changes of extracts were reduced (up to 32.1%) applying ultrasound. Significant difference was found between the total phenolic and total flavonoid content according to different varieties of fig.
To investigate the impact of pasteurisation and storage in bottle on aroma compounds in pale lage... more To investigate the impact of pasteurisation and storage in bottle on aroma compounds in pale lager beer. How was the work done: Pale lager beer was produced at an industrial scale with 100% pilsner malt and a bottom fermenting yeast. Samples were taken of unpasteurised beer from bright beer tank, after flash pasteurisation and six months after packaging in amber glass bottles. What are the main findings: Post pasteurisation, a marked increase was found in the concentration of 2,3-pentanedione (50%) and diacetyl (33%), presumably reflecting the decomposition by heat of precurser acetohydroxy acids. There was also a marginal increase in dimethyl sulphide (6%) with little or no change in other aroma compounds. Storage for six months in bottle, also resulted in an increase in the level of 2,3-pentanedione, diacetyl and dimethyl sulphide. The linear (Pearson) correlation was > 0.8 for both dimethyl sulphide and diacetyl, and 2,3-pentanedione and diacetyl. Accordingly, it was concluded that the levels in beer of dimethyl sulphide and 2,3-pentanedione are proportionally related to diacetyl. Why is the work important: This work provides an insight into the effects on flavour and aroma of lager of flash pasteurisation and subsequent storage in bottle. The inter-relationship between aroma compounds in beer suggests that such synergies may undermine the sensory perception of threshold levels and identification of specific aromas.
International Congress Flour - Bread '03 and 4th Croatian Congress of Cereal Technologists : proceedings = Međunarodni kongres Brašno-kruh '03 i 4. hrvatski kongres tehnologa proizvodnje i prerade brašna : zbornik radova, 2003
The monomeric gliadin fraction is important in contributing to bread making properties because of... more The monomeric gliadin fraction is important in contributing to bread making properties because of its viscous characteristics and interaction with polymeric glutenins. In this study 28 wheat genotypes grown at the experimental field of the Agricultural Institute Osijek in 2007 were analyzed. Composition and relative content of gliadin components has been examined by RP-HPLC method. Flour quality was defined through analysis of protein and wet gluten content, sedimentation value and gluten index, while dough rheological testing included two rheological methods, a farinographic and an extensographic. The proportion of "sulfur-poor" gliadins, ω-5 and ω-1, 2, ranged from 0.15 to 3.23 % and from 6.57 to 21.11 %, respectively. The proportion of dominant ײsulfur-richײ gliadins, α- and γ-, ranged from 38.89 to 55.18 % and from 30.09 to 52.80 %, respectively. According to obtained correlations coefficients (P≤0.05), the most pronounced relationship was found between α- and γ- gliad...
The influence of bread improver on dough rheology and bread properties was investigated. The effe... more The influence of bread improver on dough rheology and bread properties was investigated. The effect of bread improver on extensographic parameters of analyzed flours with different rheological properties was more pronounced in comparison with farinographic. Regarding the effect on bread properties, the improver enhanced loaf volume and average cell area. Using improver had possitive effect on flours with medium dough strength, through improvment of loaves volume and shape with satisfying crumb structure. However, improver significantly destroyed viscoelastic properties of flours with strong dough with negative effect on loaves shape, avarage cell area and crumb porosity parameters.
Neprerađene podzemne vode Osjecko-baranjske županije sadrže povisene koncentracije željeza, manga... more Neprerađene podzemne vode Osjecko-baranjske županije sadrže povisene koncentracije željeza, mangana, amonijaka, arsena, a također je prisutna i
Field experiments were conducted, aiming to evaluate whether the late-season foliar urea applicat... more Field experiments were conducted, aiming to evaluate whether the late-season foliar urea application (35 kg N ha−1) is effective in improving grain yield and protein-related quality in ten common wheat cultivars during two consecutive growing seasons. On average, late urea application significantly (p < 0.05) increased grain yields, thousand kernel, and hectolitre weight. The total grain protein significantly (p < 0.05) increased by 17.5% under urea application, while dough mixing behaviour was improved by increasing flour water absorption and reducing the degree of softening. Considering dough elastic properties, the changes in dough energy and maximum resistance under urea application were strongly cultivar dependent and their values compared to control varying from −12.7% to +42.4% and −25.1% to +7.7%, respectively. The distribution of grain storage proteins was significantly influenced by late urea application, but to a lesser extent than the total grain proteins. The prop...
The aim of this work is to investigate functional relationships among wheat properties, high mole... more The aim of this work is to investigate functional relationships among wheat properties, high molecular mass (weight) (HMW) glutenin subunits and bread quality produced from eleven Croatian wheat cultivars by chemometric analysis. HMW glutenin subunits were fractionated by sodium dodecylsulfate polyacrylamid gel electrophoresis (SDS-PAGE) and subsequently analysed by scanning densitometry in order to quantify HMW glutenin fractions. Wheat properties are characterised by four variables: protein content, sedimentation value, wet gluten and gluten index. Bread quality is assessed by the standard measurement of loaf volume, and visual quality of bread slice is quantified by 8 parameters by the use of computer image analysis. The data matrix with 21 columns (measured variables) and 11 rows (cultivars) is analysed for determination of number of latent variables. It was found that the first two latent variables account for 92, 85 and 87 % of variance of wheat quality properties, HMW gluteni...
Th e present paper is focused on rheology dough properties of winter wheat cultivars in relation ... more Th e present paper is focused on rheology dough properties of winter wheat cultivars in relation to bread crumb properties. Th e rheological characteristics of wheat fl our were evaluated by using Farinograph and Extensograph tests. Th e image analysis for bread crumb grain assessment was applied as alternative technique for more rapid and effi cient measurement of bread characteristics. Th e highest signifi cant positive correlation (P<0.05) was found between bread crumb properties and extensographic parameters: dough energy, maximum dough resistance and resistance to extensibility ratio. Cultivars ‘Klara’, ‘Barbara’, ‘Žitarka ’ and ‘Golubica ’ have shown fi ner and uniform bread crumbs with regard to optimal dough physicochemical characteristics. Key words bread; dough rheology; bread crumb properties; image analysis
In this paper, volume and porosity change of dough for "Krostule" during frying process... more In this paper, volume and porosity change of dough for "Krostule" during frying process in cubic, spherical, quadratic and cylindrical shapes was monitored. Dough samples were fried for different times in laboratory bath fryer at oil temperatures of 160, 170, 180 and 190 o ; C. Change of volume and porosity of fried samples was evaluated by computer image analysis and share of dark and bright colour nuances was obtained as result. According to obtained results the optimal temperature for frying dough of this type with the most even and uniform changes of volume and porosity for most samples was found to be 170 o ; C. The biggest change of volume at 170 o ; C was noticed on cylindrical dough samples with 3 mm diameter (Δ =15, 98%), while the smallest change was noticed on cylindrical dough samples with 6 mm diameter (Δ =0, 55%). The optimal share of coarse texture at 170 o ; C was noticed on spherical dough samples (1, 02-11, 45%). After the first 45 seconds of frying the a...
U radu je istrazena mogucnost primjene racunalne analize slike pri nadzoru i provjeri kakvoce u i... more U radu je istrazena mogucnost primjene racunalne analize slike pri nadzoru i provjeri kakvoce u industrijskoj proizvodnji proizvoda dekorativne kozmetike. Za tu svrhu provedena je usporedba rezultata analize tekuceg pudera i standardnog uzorka i medusobna usporedba rezultata analize svakog pojedinog uzorka analiziranog u razlicitim vremenskim intervalima. Kao podloga za nanosenje pudera izabrano je staklo cime je izbjegnut utjecaj podloge na samu boju te je omoguceno proucavanje samo utjecaja atmosfere na nju. Zbog brzine, preciznosti, objektivnosti i ponovljivosti rezultata racunalna analiza slike uzorka uspjesno se primjenjuje u mnogim industrijskim granama. U ovom istrazivanju koristen je jedan od tri algoritma za analizu slike. Napisan je izvorni racunalni program za anlizu boja iz bitmapiranog RGB formata zapisa slike (.BMP - standardni Windows bitmap format). Slike su pohranjene u rezoluciji 640x480 tocaka i u 8- bitnom zapisu (28=256) boja, a za analizu su isjecani pravokutni...
Asparagus maritimus L. is a rare species growing in the Mediterranean region and is morphological... more Asparagus maritimus L. is a rare species growing in the Mediterranean region and is morphologically similar to A. officinalis. Green asparagus, as a healthy but perishable vegetable, is processed after harvest to prevent spoilage and minimize the deterioration of its physical and chemical quality. Similar to other vegetables, changes in color, chemical and textural properties of asparagus occur during thermal treatments, such as drying. The aim of the investigation was to examine the influence of different drying temperatures on the color quality, rehydration capability and chlorophyll content in green asparagus. Drying was performed in a pilot plant tray drier. The drying temperatures for asparagus samples have varied from 40°C, 50°C, 60°C and 70°C at airflow velocity of 2, 75 ms-1. Drying temperature has a significant effect on reducing the chlorophyll content (Chla 54-71%, Chlb 37-63%), rehydration coefficient and total color change of dried ( E* = 3, 3 12, 5) and rehydrated asp...
The shares of coarse and close area were determined on bread cuts produced from nine different wh... more The shares of coarse and close area were determined on bread cuts produced from nine different wheat cultivars. Croatian wheat cultivars from Agricultural institute in Osijek (Ana, Barbara, Crvenka, Demetra, Golubica, Hana, Klara, Srpanjka i Žitarka) were used. Bread samples produced from Osijek cultivars were frozen at -10 o ; C for six months and after that shares of coarse and close area were determined. Image analysis method was applied and results of analysis of unfrozen and frozen bread loaves were compared.
U radu je numerickom analizom pokazan utjecaj izmjenjivaca topline i suncevog kolektora na poveca... more U radu je numerickom analizom pokazan utjecaj izmjenjivaca topline i suncevog kolektora na povecanje kapaciteta susare. Postavljeni model koristi izmjenjene vrijednosti za dozracenu energiju za podrucje Osijeka. Utvrđeno je da na povecanje kapaciteta utjece samo suncev kolektor dok izmjenjivac topline osigurava smanjenje utroska energenta. Rezultati proracuna za suncani dan u srpnju pokazuju da je prosjecno povecanje kapaciteta od 7.99% za isparenje vode od 300 kg/h do 24.07% za isparenje vode od 100 kg/h. Za sezonu susenja od svibnja do rujna povecanje kapaciteta je od 3.8% do 12.3% ovisno o kolicini isparene vode.
The study examined the influence of ultrasound-assisted extraction and solid-liquid extraction wi... more The study examined the influence of ultrasound-assisted extraction and solid-liquid extraction with 80% of aqueous ethanol solution on the total phenolics, total flavonoids and total colour change of extracts from different varieties of figs (Bjelica, Termenjača, Crnica, Bružetka bijela and Šaraguja). The total phenolic content was determined by using Folin Ciocalteau assay. The content of total flavonoids was measured spectrophotometrically by using the aluminium chloride colourimetric assay. Colour changes were obtained by chromameter CR-400 (Minolta) in L*a*b * colour model. Ultrasound-assisted extrac-tion showed highest total phenolic content (up to 13.72%) and total flavonoid content (up to 18.55%) compared to classic solid-liquid extraction. According to given results total colour changes of extracts were reduced (up to 32.1%) applying ultrasound. Significant difference was found between the total phenolic and total flavonoid content according to different varieties of fig.
To investigate the impact of pasteurisation and storage in bottle on aroma compounds in pale lage... more To investigate the impact of pasteurisation and storage in bottle on aroma compounds in pale lager beer. How was the work done: Pale lager beer was produced at an industrial scale with 100% pilsner malt and a bottom fermenting yeast. Samples were taken of unpasteurised beer from bright beer tank, after flash pasteurisation and six months after packaging in amber glass bottles. What are the main findings: Post pasteurisation, a marked increase was found in the concentration of 2,3-pentanedione (50%) and diacetyl (33%), presumably reflecting the decomposition by heat of precurser acetohydroxy acids. There was also a marginal increase in dimethyl sulphide (6%) with little or no change in other aroma compounds. Storage for six months in bottle, also resulted in an increase in the level of 2,3-pentanedione, diacetyl and dimethyl sulphide. The linear (Pearson) correlation was > 0.8 for both dimethyl sulphide and diacetyl, and 2,3-pentanedione and diacetyl. Accordingly, it was concluded that the levels in beer of dimethyl sulphide and 2,3-pentanedione are proportionally related to diacetyl. Why is the work important: This work provides an insight into the effects on flavour and aroma of lager of flash pasteurisation and subsequent storage in bottle. The inter-relationship between aroma compounds in beer suggests that such synergies may undermine the sensory perception of threshold levels and identification of specific aromas.
International Congress Flour - Bread '03 and 4th Croatian Congress of Cereal Technologists : proceedings = Međunarodni kongres Brašno-kruh '03 i 4. hrvatski kongres tehnologa proizvodnje i prerade brašna : zbornik radova, 2003
The monomeric gliadin fraction is important in contributing to bread making properties because of... more The monomeric gliadin fraction is important in contributing to bread making properties because of its viscous characteristics and interaction with polymeric glutenins. In this study 28 wheat genotypes grown at the experimental field of the Agricultural Institute Osijek in 2007 were analyzed. Composition and relative content of gliadin components has been examined by RP-HPLC method. Flour quality was defined through analysis of protein and wet gluten content, sedimentation value and gluten index, while dough rheological testing included two rheological methods, a farinographic and an extensographic. The proportion of "sulfur-poor" gliadins, ω-5 and ω-1, 2, ranged from 0.15 to 3.23 % and from 6.57 to 21.11 %, respectively. The proportion of dominant ײsulfur-richײ gliadins, α- and γ-, ranged from 38.89 to 55.18 % and from 30.09 to 52.80 %, respectively. According to obtained correlations coefficients (P≤0.05), the most pronounced relationship was found between α- and γ- gliad...
The influence of bread improver on dough rheology and bread properties was investigated. The effe... more The influence of bread improver on dough rheology and bread properties was investigated. The effect of bread improver on extensographic parameters of analyzed flours with different rheological properties was more pronounced in comparison with farinographic. Regarding the effect on bread properties, the improver enhanced loaf volume and average cell area. Using improver had possitive effect on flours with medium dough strength, through improvment of loaves volume and shape with satisfying crumb structure. However, improver significantly destroyed viscoelastic properties of flours with strong dough with negative effect on loaves shape, avarage cell area and crumb porosity parameters.
Neprerađene podzemne vode Osjecko-baranjske županije sadrže povisene koncentracije željeza, manga... more Neprerađene podzemne vode Osjecko-baranjske županije sadrže povisene koncentracije željeza, mangana, amonijaka, arsena, a također je prisutna i
Field experiments were conducted, aiming to evaluate whether the late-season foliar urea applicat... more Field experiments were conducted, aiming to evaluate whether the late-season foliar urea application (35 kg N ha−1) is effective in improving grain yield and protein-related quality in ten common wheat cultivars during two consecutive growing seasons. On average, late urea application significantly (p < 0.05) increased grain yields, thousand kernel, and hectolitre weight. The total grain protein significantly (p < 0.05) increased by 17.5% under urea application, while dough mixing behaviour was improved by increasing flour water absorption and reducing the degree of softening. Considering dough elastic properties, the changes in dough energy and maximum resistance under urea application were strongly cultivar dependent and their values compared to control varying from −12.7% to +42.4% and −25.1% to +7.7%, respectively. The distribution of grain storage proteins was significantly influenced by late urea application, but to a lesser extent than the total grain proteins. The prop...
The aim of this work is to investigate functional relationships among wheat properties, high mole... more The aim of this work is to investigate functional relationships among wheat properties, high molecular mass (weight) (HMW) glutenin subunits and bread quality produced from eleven Croatian wheat cultivars by chemometric analysis. HMW glutenin subunits were fractionated by sodium dodecylsulfate polyacrylamid gel electrophoresis (SDS-PAGE) and subsequently analysed by scanning densitometry in order to quantify HMW glutenin fractions. Wheat properties are characterised by four variables: protein content, sedimentation value, wet gluten and gluten index. Bread quality is assessed by the standard measurement of loaf volume, and visual quality of bread slice is quantified by 8 parameters by the use of computer image analysis. The data matrix with 21 columns (measured variables) and 11 rows (cultivars) is analysed for determination of number of latent variables. It was found that the first two latent variables account for 92, 85 and 87 % of variance of wheat quality properties, HMW gluteni...
Th e present paper is focused on rheology dough properties of winter wheat cultivars in relation ... more Th e present paper is focused on rheology dough properties of winter wheat cultivars in relation to bread crumb properties. Th e rheological characteristics of wheat fl our were evaluated by using Farinograph and Extensograph tests. Th e image analysis for bread crumb grain assessment was applied as alternative technique for more rapid and effi cient measurement of bread characteristics. Th e highest signifi cant positive correlation (P<0.05) was found between bread crumb properties and extensographic parameters: dough energy, maximum dough resistance and resistance to extensibility ratio. Cultivars ‘Klara’, ‘Barbara’, ‘Žitarka ’ and ‘Golubica ’ have shown fi ner and uniform bread crumbs with regard to optimal dough physicochemical characteristics. Key words bread; dough rheology; bread crumb properties; image analysis
In this paper, volume and porosity change of dough for "Krostule" during frying process... more In this paper, volume and porosity change of dough for "Krostule" during frying process in cubic, spherical, quadratic and cylindrical shapes was monitored. Dough samples were fried for different times in laboratory bath fryer at oil temperatures of 160, 170, 180 and 190 o ; C. Change of volume and porosity of fried samples was evaluated by computer image analysis and share of dark and bright colour nuances was obtained as result. According to obtained results the optimal temperature for frying dough of this type with the most even and uniform changes of volume and porosity for most samples was found to be 170 o ; C. The biggest change of volume at 170 o ; C was noticed on cylindrical dough samples with 3 mm diameter (Δ =15, 98%), while the smallest change was noticed on cylindrical dough samples with 6 mm diameter (Δ =0, 55%). The optimal share of coarse texture at 170 o ; C was noticed on spherical dough samples (1, 02-11, 45%). After the first 45 seconds of frying the a...
U radu je istrazena mogucnost primjene racunalne analize slike pri nadzoru i provjeri kakvoce u i... more U radu je istrazena mogucnost primjene racunalne analize slike pri nadzoru i provjeri kakvoce u industrijskoj proizvodnji proizvoda dekorativne kozmetike. Za tu svrhu provedena je usporedba rezultata analize tekuceg pudera i standardnog uzorka i medusobna usporedba rezultata analize svakog pojedinog uzorka analiziranog u razlicitim vremenskim intervalima. Kao podloga za nanosenje pudera izabrano je staklo cime je izbjegnut utjecaj podloge na samu boju te je omoguceno proucavanje samo utjecaja atmosfere na nju. Zbog brzine, preciznosti, objektivnosti i ponovljivosti rezultata racunalna analiza slike uzorka uspjesno se primjenjuje u mnogim industrijskim granama. U ovom istrazivanju koristen je jedan od tri algoritma za analizu slike. Napisan je izvorni racunalni program za anlizu boja iz bitmapiranog RGB formata zapisa slike (.BMP - standardni Windows bitmap format). Slike su pohranjene u rezoluciji 640x480 tocaka i u 8- bitnom zapisu (28=256) boja, a za analizu su isjecani pravokutni...
Asparagus maritimus L. is a rare species growing in the Mediterranean region and is morphological... more Asparagus maritimus L. is a rare species growing in the Mediterranean region and is morphologically similar to A. officinalis. Green asparagus, as a healthy but perishable vegetable, is processed after harvest to prevent spoilage and minimize the deterioration of its physical and chemical quality. Similar to other vegetables, changes in color, chemical and textural properties of asparagus occur during thermal treatments, such as drying. The aim of the investigation was to examine the influence of different drying temperatures on the color quality, rehydration capability and chlorophyll content in green asparagus. Drying was performed in a pilot plant tray drier. The drying temperatures for asparagus samples have varied from 40°C, 50°C, 60°C and 70°C at airflow velocity of 2, 75 ms-1. Drying temperature has a significant effect on reducing the chlorophyll content (Chla 54-71%, Chlb 37-63%), rehydration coefficient and total color change of dried ( E* = 3, 3 12, 5) and rehydrated asp...
The shares of coarse and close area were determined on bread cuts produced from nine different wh... more The shares of coarse and close area were determined on bread cuts produced from nine different wheat cultivars. Croatian wheat cultivars from Agricultural institute in Osijek (Ana, Barbara, Crvenka, Demetra, Golubica, Hana, Klara, Srpanjka i Žitarka) were used. Bread samples produced from Osijek cultivars were frozen at -10 o ; C for six months and after that shares of coarse and close area were determined. Image analysis method was applied and results of analysis of unfrozen and frozen bread loaves were compared.
U radu je numerickom analizom pokazan utjecaj izmjenjivaca topline i suncevog kolektora na poveca... more U radu je numerickom analizom pokazan utjecaj izmjenjivaca topline i suncevog kolektora na povecanje kapaciteta susare. Postavljeni model koristi izmjenjene vrijednosti za dozracenu energiju za podrucje Osijeka. Utvrđeno je da na povecanje kapaciteta utjece samo suncev kolektor dok izmjenjivac topline osigurava smanjenje utroska energenta. Rezultati proracuna za suncani dan u srpnju pokazuju da je prosjecno povecanje kapaciteta od 7.99% za isparenje vode od 300 kg/h do 24.07% za isparenje vode od 100 kg/h. Za sezonu susenja od svibnja do rujna povecanje kapaciteta je od 3.8% do 12.3% ovisno o kolicini isparene vode.
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