Upotreba prediktivnih modela za analizu rasta Bifidobacterium animalis subsp. lactis Bb-12 u kravljem, kozjem i sojinom mlijeku

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.Cilj rada bio je upotrijebiti jedan od prediktivnih modela rasta bakterija za analizu rasta probiotičkog soja Bifidobacterium animalis subsp. lactis Bb-12 u kravljem, kozjem i sojinom mlijeku. Korišten je Gompertzov model, a prikladnost modela je procijenjena Schnuteovim algoritmom. Osim za analizu rasta Bifidobacterium animalis subsp. lactis Bb-12, Gompertzov model korišten je i za analizu kretanja pH vrijednosti tijekom fermentacije. Eksperimentalni rezultati, kao i vrijednosti kinetičkih parametara, dobiveni u ovom radu, pokazali su da je najveća brzina rasta Bifidobacterium animalis subsp. lactis Bb-12 bila u kozjem mlijeku, a najmanja u sojinom mlijeku. Suprotno u odnosu na rast Bifidobacterium animalis subsp. lactis Bb-12, pH vrijednost opadala je brže u sojinom mlijeku nego u kravljem. Najveći pad pH bio je također u kozjem mlijeku, što potvrđuju rezultati naših prethodnih studija kao i rezultati drugih autora. Gompertzov model pokazao se pogodnim za analizu tijeka i kinetike fermentacije u ove tri vrste mlijeka i može se koristiti za analizu kinetike rasta drugih probiotičkih i starter kultura u mlijeku

Influence of malting procedure on the quality of hulless barley malt

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 (Kolbach index), Hartong number, friability, extract, fine/coarse difference, colour, boiled wort colour, pH, viscosity and filterability of wort, and β-glucans were investigated. Based on obtained results, and their comparison to results reported in scientific and technical literature, the efficacy of each micromalting procedure was evaluated, considering recommended values for hulless barley malt. The results indicate that the resistance to deeper modification of grain (expressed as lower water absorption during soaking grains, and as weaker friability) are the main problem that will need to be solved in the further selection processes of domestic hulless 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

Brašno - Kruh '15

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

Study on influence of process parameters during malting on protein solubility

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 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)

Determination of β-glucans content in domestic varieties of malting barley

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 za daljnja istraživanja selekcionarima ječma pri nastavku sortnih pokusa s ciljem oplemenjivanja sorti, ali i tehnolozima u sladarstvu za odabir pogodnih sorti za proizvodnju pivarskog slada.This paper considers the share of β-glucans in domestic barley varieties with special review on malt and brewing industry recommended values. Samples were gathered as a strictly brewing (B), feed (F) and, so called combined (BF) varieties which can be used for malting, but also for some other purpose. Total of 12 varieties were examined. Also, three locations were considered (Slavonski Brod, Tovarnik and Osijek) in this investigation. The obtained results indicate that most of examined varieties (considering the β-glucan share) were within recommended values or slightly above them. Results also indicate that varieties are easily classified into aforementioned groups (B, F, BF), and that variety affects the share of β-glucans and location does not affect the share of β-glucans in a way that is statistically significant (p < 0.05). Furthermore, results show that in total examined spectrum of varieties there are domestic varieties which have excellent or very good values for β-glucan (Gazda, Barun) in comparison with standard varieties (German varieties Vanessa and Tiffany). Barley breeders can use these results as a basic for future breeding experiments, but also engineers can use this data for selection of suitable varieties for malt production

Determination of β-glucans content in domestic varieties of malting barley

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 za daljnja istraživanja selekcionarima ječma pri nastavku sortnih pokusa s ciljem oplemenjivanja sorti, ali i tehnolozima u sladarstvu za odabir pogodnih sorti za proizvodnju pivarskog slada.This paper considers the share of β-glucans in domestic barley varieties with special review on malt and brewing industry recommended values. Samples were gathered as a strictly brewing (B), feed (F) and, so called combined (BF) varieties which can be used for malting, but also for some other purpose. Total of 12 varieties were examined. Also, three locations were considered (Slavonski Brod, Tovarnik and Osijek) in this investigation. The obtained results indicate that most of examined varieties (considering the β-glucan share) were within recommended values or slightly above them. Results also indicate that varieties are easily classified into aforementioned groups (B, F, BF), and that variety affects the share of β-glucans and location does not affect the share of β-glucans in a way that is statistically significant (p < 0.05). Furthermore, results show that in total examined spectrum of varieties there are domestic varieties which have excellent or very good values for β-glucan (Gazda, Barun) in comparison with standard varieties (German varieties Vanessa and Tiffany). Barley breeders can use these results as a basic for future breeding experiments, but also engineers can use this data for selection of suitable varieties for malt production

Study on influence of process parameters during malting on protein solubility

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 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)