Goran Gagula - Academia.edu (original) (raw)

Papers by Goran Gagula

Journal of the Institute of Brewing, Apr 29, 2024

Mljekarstvo : časopis za unaprjeđenje proizvodnje i prerade mlijeka, Nov 25, 2013

The aim of this study was to use a predictive model to analyse the growth of a probiotic strain B... more The aim of this study was to use a predictive model to analyse the growth of a probiotic strain Bifidobacterium animalis subsp. lactis Bb-12 in cow's, goat's and soy milk. The Gompertz model was used, and the suitability of the model was estimated by the Schnute algorithm. Except for the analysis of Bifidobacterium animalis subsp. lactis Bb-12 growth, the Gompertz model was also used for the analysis of pH changes during the fermentation process. Experimental results, as well as the values of kinetic parameters obtained in this study, showed that the highest growth rate of Bifidobacterium animalis subsp. lactis Bb-12 was obtained in goat's milk, and the lowest in soy milk. Contrary to the growth of Bifidobacterium animalis subsp. lactis Bb-12, pH decreased faster in soy milk than in cow's milk. The highest rate of pH decrease was also observed in goat's milk, which is in correspondence with results of various previous studies. The Gompertz model proved to be highly suitable for analysing the course and the fermentation kinetics in these three kinds of milk, and might be used to analyse the growth kinetics of other probiotic and starter cultures in milk.

U radu je ispitivan utjecaj postupka slađenja pri proizvodnji svijetlog pšeničnog slada na udio t... more U radu je ispitivan utjecaj postupka slađenja pri proizvodnji svijetlog pšeničnog slada na udio topljivog N u sladu, odnos ukupnog N i topljivog N (Kolbachov indeks). Ispitivani su uzorci osam domaćih pšenica kvalitativne grupe B (krušarice) koje karakterizira povišen udio ukupnog N u zrnu. Uzorci su uzimani tijekom dvije sezone (2008 i 2009). Provedeno je pet postupaka slađenja i to: (A) standardni postupak (kontrola); (B) restriktivni postupak s jakim porastom temperature tijekom klijanja; (C) intenzivni postupak s jakim padom temperatura tijekom klijanja; (D) umjereno intenzivni postupak s blagim padom temperatura tijekom klijanja; (E) umjereno restriktivni postupak s blagim porastom temperatura tijekom klijanja. Rezultati pokazuju da umjereno restriktivni postupak slađenja (E) daje najbolje rezultate kako za topljivi N u sladovini tako i za odnos ukupnog N i topljivog N (Kolbachov indeks).The aim of this work was to conduct influence of malting during light wheat malt production...

Journal of the American Society of Brewing Chemists

Proceedings contains 28 original research articles presented at 8th International Congress Flour ... more Proceedings contains 28 original research articles presented at 8th International Congress Flour – Bread ’15 and 10th Croatian Congress of Cereal Technologists Brašno – Kruh ’1

U radu je ispitivan udjel β-glukana u domaćim sortama ječma s posebnim osvrtom na preporučene vri... more U radu je ispitivan udjel β-glukana u domaćim sortama ječma s posebnim osvrtom na preporučene vrijednosti sladarske i pivarske industrije. Uzorci sorti su prikupljeni kao striktno pivarske (B), striktno stočne (F) i kao tzv. kombinirane sorte (BF) koje se mogu koristiti i za slađenje i za druge namjene, sa tri lokacije (Slavonski brod, Tovarnik i Osijek). Ukupno je ispitano 12 sorti. Dobiveni rezultati pokazuju da je većina ispitivanih sorti (s obzirom na udjel β-glukana) bila u okviru preporučenih vrijednosti ili malo iznad. Rezultati također ukazuju da se sorte vrlo jasno razvrstavaju u određene grupe (B, F, BF), te da faktor sorta utječe, dok faktor lokacija ne utječe statistički značajno (p < 0,05) na udjel β-glukana. Nadalje, rezultati pokazuju da u ukupnom ispitivanom sortimentu postoje domaće sorte koje imaju odlične ili vrlo dobre vrijednosti za β -glukan (Gazda, Barun) u komparaciji sa standardima (njemačke sorte Vanessa i Tiffany). Dobiveni rezultati mogu biti podloga z...

8th International Congress Flour - Bread '15 [and] 10th Croatian Congress of Cereal Technologists, 2016

8 th INTERNATIONAL CONGRESS FLOUR – BREAD ‘15 10th CROATIAN CONGRESS OF CEREAL TECHNOLOGISTS, 2015

This paper investigated the influence of malting procedure on quality indicators of naked barley ... more This paper investigated the influence of malting procedure on quality indicators of naked barley malt according recommended properties for standard pale malt. The aim was to determine the optimal malting procedure in order to achieve the best results for investigated indicators in relation to the recommended values. The influence of four malting procedure on soluble N share in malt, total N and soluble N ratio (Kolbach index), Hartong number, friability, extract, fine/coarse difference, colour, boiled wort colour, pH, viscosity and filterability of wort, and β-glucane was tested. Malted sample was two domestic naked barley variety (Matko and GZ 184). Four malting procedures have been conducted: (A) standard procedure – control ; (B) gently intensive procedure with uniform temperature increase during germination till the end of the process ; (C) moderately intensive procedure with increase in germination temperature on the second and third day, and constant germination temperature till the end of the process ; (D) procedure with sudden germination temperature decrease after the first day, and constant temperature till the end of the process ; . Based on obtained results, and their comparison to results in scientific and technical literature, the efficacy of certain micromalting procedure was evaluated, considering recommended properties of naked barley malt. The results indicate that the resistance to deeper modification of grains (expressed as lower water absorption during soaking grains, and as weaker friability) obviously be the main problem that will need to be solved in the further process of the selection of domestic naked barley varieties for malting. The intensification of the process of germination should be combined with the extension of soaking time, which should lead to improvements of friability of malt and better value for other indicators of malt quality.

Sveučilište Josipa Jurja Strossmayera u Osijeku. Prehrambeno-tehnološki fakultet Osijek. Zavod za procesno inženjerstvo. Katedra za modeliranje, optimiranje i automatizaciju., Oct 7, 2017

Sveučilište Josipa Jurja Strossmayera u Osijeku. Prehrambeno-tehnološki fakultet Osijek. Zavod za prehrambene tehnologije. Katedra za tehnologije prerade žitarica., Apr 5, 2013

U radu je ispitivan utjecaj postupka slađenja pri proizvodnji svijetlog psenicnog slada na udio t... more U radu je ispitivan utjecaj postupka slađenja pri proizvodnji svijetlog psenicnog slada na udio topljivog N u sladu, odnos ukupnog N i topljivog N

The aim of this work was to conduct influence of malting during light wheat malt production on sh... more The aim of this work was to conduct influence of malting during light wheat malt production on share of soluble N in malt, and total N and soluble N (Kolbach index) ratio. Eight domestic wheat varieties of quality group B were conducted. They are characterized by increased share of total N in grain. Samples were taken during two seasons (2008 and 2009). Five malting procedures were conducted: standard procedure (A, control), restrictive procedure with high temperature increase during germination (B), intense procedure with high temperature decrease during germination (C), moderately intense procedure with moderate temperature decrease during germination (D), moderately restrictive procedure with moderate temperature increase during germination (E). Results show that procedure E gives best results for soluble N in worth and also for total N/soluble N ratio (Kolbach index).

This paper investigated the influence of malting procedure on quality indicators of hulless (nake... more This paper investigated the influence of malting procedure on quality indicators of hulless (naked) barley malt according to the recommended values for standard pale malt. The aim was to determine the optimal malting procedure in order to achieve the best results for investigated indicators in relation to the recommended values. Two domestic hulless barley varieties (Matko and GZ-184) were malted and four malting procedures were applied: (A) standard procedure – control; (B) gently intensive procedure with uniform temperature increase during germination till the end of the process; (C) moderately intensive procedure with the increase of germination temperature on the second and third day, and constant germination temperature till the end of the process; (D) procedure with sudden germination temperature decrease after the first day, and constant temperature till the end of the process. The influence of four malting procedures on soluble N content in malt, total N and soluble N ratio ...

Mljekarstvo, Nov 25, 2013

Journal of the Institute of Brewing, 2016

The aim of this research was to create mathematical models for describing the changes in beer pro... more The aim of this research was to create mathematical models for describing the changes in beer properties by using two chemometric methods applied on the experimental data. The models are intended to be useful and trustworthy for calculating four beer properties based on three easily measured ones. For that purpose, lager and malt beer were packaged in glass bottles, while lager beer was also packaged in polyethylene terephthalate (PET). Samples were placed at room temperature in the dark for 6 months. Fifteen physical and chemical properties of the beer were measured before bottling, immediately after bottling and once per month for the next 6 months. Standard MEBAK and Analytica-EBC methods of analysis were applied. During the 6 month period, seven properties changed >1%. Two partial least squares regression methods [polynomial regression, partial least squares regression with polynomial regression (PLSR-PR) and response surface method (PLSR-RSM)] were used for modelling the relationships amongst multivariate measurements. Models with high statistical significance were determined and two PLSR methods were compared. Both chemometric methods were found to be suitable for modelling physical and chemical changes in the beers during their commercial shelf-life. The PLS-RSM method was found to be the more precise and confident method in describing property changes for lager and malt beer in glass bottles, while the polynomial regression model was found to be better for the lager beer packaged in PET. The R 2 values determined for polynomial regression model were up to 0.939, while for the random surface method model the values were up to 1.000.

Food Packaging and Shelf Life, 2020

This research aimed to evaluate the influence of different packaging materials (glass bottle, PET... more This research aimed to evaluate the influence of different packaging materials (glass bottle, PET bottle, aluminium can and keg) on eleven (acetaldehyde, dimethyl sulphite, ethyl acetate, isoamyl acetate, propanol, isobutanol, isoamyl alcohol, diacetyl, higher alcohols, esters and pentanedione) industrial pale lager beer volatile compounds concentration changes and their stability during a six-month storage time. The analyses were performed on a single type of pale lager beer under different packaging regimes. The results showed that diacetyl and pentanedione were significantly higher in PET bottles than in other packaging (especially glass bottle). Dimethyl sulphide concentration was, at the end of a six month storage, significantly lower (5 μg/L) in PET bottles than in glass bottle (48 μg/L). Can and keg also showed good preservation properties for volatiles. This is important for the brewing industries because the reported changes influence the consumers' perception and greatly affect the acceptance of beer.