Karakterizacija albumina i biohemijski aspekti kvaliteta pšenice (Triticum aestivum)
| Autor: | Tomić Jelena |
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| Jazyk: | srbština |
| Rok vydání: | 2016 |
| Předmět: | |
| Druh dokumentu: | Diplomová práce |
| Popis: | U okviru disertacije ispitivan je uticaj sorte i mikroklimatskih uslova tokom dve proizvodne godine pšenice na sadržaj i strukturu albumina; izvršena je karakterizacija albumina pomoću Lab–on– a–Chip elektroforeze; određena je aktivnost proteolitičkih i amilolitičkih enzima, sadržaj slobodnih sulfhidrilnih i slobodnih amino grupa; ispitana su reološka svojstva testa primenom uobičajenih metoda za procenu tehnološkog kvaliteta brašna i izvedena je karakterizacija gotovog proizvoda-hleba. Jedan deo istraživanja se odnosio na period posležetvenog dozrevanja pšenice i stabilizacije brašna.Obe ispitivane godine odlikovao je toplotni stres s tim što su u 2012. godini maksimalnetemperature prelazile 35 °C i broj tropskih dana je bio izrazito veći u odnosu na 2011., što je uslovilo promene u sastavu i kvalitetu proteina i skroba u zrnu pšenice. Sadržaj ukupnih albumina uzoraka pšeničnog brašna iz 2012. bio je značajno manji u odnosu na 2011. proizvodnu godinu. Rezultati određivanja proteolitičke i amilolitičke aktivnosti uzoraka pšeničnog brašna iz dve proizvodne godine su pokazali da su za 2012. proizvodnu godinu karakteristične znatno niže vrednosti ovih pokazatelja u odnosu na 2011. proizvodnu godinu i da je enzimska aktivnost pre svega sortna karakteristika.Sadržaj slobodnih sulfhidrilnih grupa uzoraka pšeničnog brašna iz 2012. proizvodne godine bio je značajno veći dok je sadržaj disulfidnih veza bio manji u odnosu na 2011. Sadržaj slobodnih amino grupa se razlikovao između uzoraka iz dve proizvodne godine, kako između različitih sorti, tako i u pogledu sva tri primenjena tretmana inkubacije glutena. Značajne razlike između vrednosti slobodnih amino grupa izmerenih nakon inkubacije gluten na 37 °C, ukazuju na različitu proteolitičku aktivnost ispitivanih uzoraka pšeničnih sorti. U poređenju sa uzorcima iz 2011. proizvodne godine, uzorci iz 2012. su imali znatno niže vrednosti specifične zapremine hleba.Dodatkom dvostruke količine sopstvenih albumina odabranom setu uzoraka dobijenisu rezultati, koji ukazuju da su uzorci brašna iz 2011. imali manjak amilolitičkih enzima, a uzorci iz 2012. manjak proteolitičkih enzima za postizanje optimalnog tehnološkog kvaliteta. In this dissertation, the influence of variety and microclimatic conditions that prevailed during the two production years on the content and structure of wheat albumins were investigated; characterization of albumins was performed by Lab-on-a-Chip capillary electrophoresis; the proteolytic and α- amylolytic activity, as well as the content of free sulfhydryl and free amino groups were also determined; the rheological properties of dough were estimated using conventional methods for the assessment of flour technological quality and characterization of the final product- bread was performed. One part of the research covered the period of postharvest wheat and flour maturation. Heat stress was characteristic of both production years; however, in 2012, maximum temperatures exceeded 35 °C and the number of days with maximum temperatures above 30 °C was markedly higher than in the 2011 production year. These conditions have caused the changes in the composition and quality of protein and starch in wheat kernels. The albumin content of wheat flour samples from 2012 was significantly lower compared to 2011 production year. Results of proteolytic and amilolytic activities of wheat flour samples from two production years, showed that the values of these indicators were significantly lower for 2012 in relation to the 2011 production year, and that the enzyme activity is primarily varietal characteristic. The content of free sulfhydryl groups of wheat flour samples from the 2012 production year was significantly higher while the content of disulfide bonds was lower than in 2011. The content of free amino groups differed between samples from two production years. Differences in the amount of free amino content were evident between the varieties and between different treatments of gluten incubation. Significant differences between the values of the free amino groups measured after gluten incubation at 37 °C, indicate a different proteolytic activity of tested wheat flour samples. In comparison with the samples from the 2011 production year, samples from 2012 had significantly lower values of specific bread volume. The addition of double amount of its own albumins to the selected samples indicated that the flour samples from 2011 had a deficit of amylolytic enzymes and samples from 2012 had a deficit of proteolytic enzymes for achieving optimal technological quality. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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