<p>U radu je ispitana interakcija tri vrste komercijalnih prehrambenih vlakana (Fibrex, inulin HPX i inulin GR) sa strukturnim komponentama hlebnog testa. Na različitim pH vrednostima (pH 7, pH 5, pH 4 i pH 3) ispitane su fizikohemijske osobine vlakana, pri čemu Fibrex ima najveći kapacitet zadržavanja vode od 421% dok inulin GR najmanji od svega 4.2%. Na osnovu reološke osobina testa sa vlaknima u količini od 5 i 10% dobijen je uvid u interakciju vlakana sa proteinskim kompleksom i klajsterisanim skrobom. Reološke osobine hlebnog testa zavise od količine i vrste inkorporiranih vlakana dok pH vrednost vode za zames ima mali uticaj na ove pokazatelje. Dodatkom 5 i 10% fibrex-a i inulina HPX dobija se hleb dobrog kvaliteta, sa značajnim padom svarljivih ugljenih hidrata i promenjenog nutritivnog sastava koji ima osobine funkcionalne hrane pri čemu fibrex tamni boju a inulin HPX i GR vizuelno ne menja boju hleba u odnosu na hleb bez vlakana. Statistička obrada podataka je potvrdila pozitivan uticaj vlakana na testa u zamrznutom stanju. Koeficijenti diskriminacije pokazuju da je najveći uticaj vlakana na završnu fermentaciju testa je posle 1 dana (199.006 i 5.739), a pozitivan uticaj vlakana na zapreminu hleba izražen je posle 30 dana (9.416) a na kvalitet sredine posle 60 dana (.841). Termodinamičkim merenjima kinetike zamrzavanja/odmrzavanja testa sa vlaknima utvrđeno je da inulina GR doprinosi skraćenju postupka što potvrđuje koeficient determinacije R2 (0.966 i 0.981) dok testo sa fibrexom ima najmanji koeficijent determinacije R2 (0.939 i 0.951) što pokazuje da ovo vlakno najlošije utiče na kinetiku zamrzavanja/odmrzavanja. Kinetika zamrzavanja/odmrzavanja može se definisati matematičkim modelom koja odgovara jednačini sa kvadratnim polinom , odnosno jednačini za nestacionarni temperaturni profil sa kvadratnim članom Y= b<sub>0</sub>+b<sub>1</sub><sup>*</sup>X +b<sub>2</sub><sup>*</sup>X<sup>2</sup>.</p> / <p>The interaction of three different commercial<br />fibers (Fibrex, inulin HPX and inulin GR) with<br />structural elements of bread dough was tested.<br />Physico/chemical fiber characteristics at<br />different pH values point that the greatest<br />water binding capacity (421%) is attributed to<br />fibrex, contrary to the value of 4,2%<br />experienced for inulin GR. Rheology of dough<br />containing 0 to 10% of either fiber type proved<br />the insight in the interaction between fibers<br />and proteins and also fibers and starch gels.<br />Dough rheology is influenced the most by fiber<br />characteristics and incorporated quantity,<br />contrary to pH value of water at mixing stage.<br />Statistical data interpretation proved the<br />positive contribution of fibers on dough at<br />freezing<br />Discrimination coefficients are confirming that,<br />on the whole, the greatest influence fibers have<br />on final proof after1 day of freezing (199.006<br />and 5.739) and their beneficial influence is<br />experienced after 30 and 60 days of freezing on<br />bread volume (9.416) and bread crumb quality<br />(0.841), respectively. Thermodynamic<br />measuring of freezing/thawing kinetics of<br />dough containing fibers point that inulin GR is<br />beneficial in shortening the procedure,<br />confirmed by values for determination<br />coefficient R² (0.966 and 0.981), contrary to the<br />contribution of Fibrex where the smallest<br />values for those coefficients were experienced,<br />R² (0.939 and 0.951 proving that fibrex is not<br />contributing to the freezing/thawing kinetics.<br />Freezing/thawing kinetics can be adequately<br />defined by the mathematical model of square<br />polynomial, i.e. equation for the non stationary<br />temperature profile with square Y= b<sub>0</sub>+b<sub>1</sub><sup>*</sup>X +b<sub>2</sub><sup>*</sup>X<sup>2</sup>.</p><p>Data presented in this thesis show that,<br />understanding interactions between fibers and<br />dough structure, by the addition of 5 or 10% of<br />either Fibrex or inulin HPX, high quality bread<br />attributed with a significant decrease of<br />digestible carbohydrates and modified nutritive<br />pattern accompanied with attributes of<br />functional food can be made, while Fibrex is<br />adversly contributing to crumb colour contrary<br />to inulin HPX and GR.</p>
| Identifer | oai:union.ndltd.org:uns.ac.rs/oai:CRISUNS:(BISIS)71247 |
| Date | 30 October 2009 |
| Creators | Filipović Jelena |
| Contributors | Popov Stevan, Psodorov Đorđe, Veljković Vladimir |
| Publisher | Univerzitet u Novom Sadu, Tehnološki fakultet Novi Sad, University of Novi Sad, Faculty of Technology at Novi Sad |
| Source Sets | University of Novi Sad |
| Language | Serbian |
| Detected Language | English |
| Type | PhD thesis |
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