master's thesis
Development of enzymatic activity of wheat grain during germination process

Krešimir Rušnov (2011)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Process Engineering
Sub-department of Bioprocess Engineering
Metadata
TitleRazvoj enzimske aktivnosti zrna tijekom klijanja pšenice u kontroliranim uvjetima
AuthorKrešimir Rušnov
Mentor(s)Vinko Krstanović (thesis advisor)
Abstract
U radu je ispitivan razvoj enzimske snage zrna pšenice tijekom klijanja (izražen kao aktivnost α-amilaze i ukupne dijastatse snage). Cilj je bio ustanoviti optimalno vrijeme klijanja zrna radi postizanja najboljih vrijednosti za ispitivane pokazatelje prema preporučenim vrijednostima. Provedeno je klijanje uzoraka pšenice u kontroliranim uvjetima s obzirom na temperaturu i vlažnost zraka tijekom 7 dana. Dobiveni rezultati za ukupnu dijastatsku snagu kretali su se u rasponu od 240 °WK (polazni uzorak) do maximalne vrijednosti od 420°WK na kraju procesa klijanja. Rezultati za aktivnost α-amilaze kretali su se u rasponu od 0 DU/s.tv. (polazni uzorak) do 60 DU/s. tv. na kraju procesa klijanja. Ustanovljeno je da vrijeme klijanja od 156-168 h (od polovine petog dana do šestog dana klijanja) optimalno za dobiv.anje vrijednosti koje su preporučene za pšenični slad (dijastatska snaga 250-420 °WK, α-amilaze aktivnost α-amilaze 40-60 DU/s. tv). Zadovoljavajući rezultati postignuti su već polovinom četvrtog dana klijanja (dijastatska snaga »300 °WK, I aktivnost α-amilaze »28 DU/s. tv.). Nadalje ustanovljeno je da produljenjem vremena klijanja preko 168 h nema značajnijeg porasta vrijednosti ni za jedan od ispitivanih pokazatelja, ali dolazi do značajnog narušavanja ostalih pokazatelja kakvoće slada. Iz dobivenih reztultata može se zaključiti da optimalno vrijeme za sintezu enzima koji utječu na ukupnu dijastatsku snagu slada (izuzev α-amilaze koja se samo aktivira u procesu klijanja) i sintezu α-amilaze leži između 156 - 168 sati klijanja, ali ako se želi napraviti kompromis između vrijednosti ovih pokazatelja i ostalih važnih pokazatelja kakvoće slada tada optimalan vremenski raspon za klijanje zrna leži između 120 - 140 sati klijanja.
Keywordswheat germination α-amylase diastatic power malting optimization
Parallel title (English)Development of enzymatic activity of wheat grain during germination process
Committee MembersDaliborka Koceva Komlenić (committee chairperson)
Vinko Krstanović (committee member)
Vedran Slačanac (committee member)
Jurislav Babić (committee member)
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Process Engineering
Sub-department of Bioprocess Engineering
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Engineering
Study programme typeuniversity
Study levelgraduate
Study programmeFood Technology and Process Engineering
Academic title abbreviationdipl. ing.
Genremaster's thesis
Language Croatian
Defense date2011-12-09
Parallel abstract (English)
This paper investigated development of enzymatic power in wheat grain during germination process (expressed as α-amylase activity and total diastatic power). The aim was to determine the optimal germination time in order to achieve the best results for investigated indicators in relation to the recommended values. Wheat samples underwent germination process in controlled conditions, regarding temperature and air humidity, over a period of 7 days. Obtained results for total distatic power were in range from 240° WK in starting sample to 420° WK at the end of the germination process. Results for α-amylase activity were in range from 0 DU/dm in starting sample to 60 DU/dm at the end of germination process. It was determined that germination time ranging from 158 to 168 h (from 5.5th – 6th day of germination) is optimal to obtain recommended values for wheat malt (diastatic power 250 – 420 °WK, α-amylase activity 40 - 60 DU/dm). Satisfying results were achieved on the half of the 4th day of germination (diastatic power ≈ 300 °WK, α-amylase activity ≈ 28 DU/dm). Furthermore, it was determined that by extending the germination time beyond 168 h no significant up growth of any of investigated indicators occurred, though other investigated indicators of malt quality were distorted. In conclusion, obtained results indicate that optimal germination time for synthesis of enzymes that affect the total diastatic power of malt (except β-amylase which is activated only during the germination process) and α-amylase synthesis, is between 156 - 168 h. In case of compromising these indicator values with the rest of important malt quality indicators, the optimal germination time ranges from 120 - 140 h.
Parallel keywords (Croatian)pšenica klijanje α-amilaza dijastatska snaga
Resource typetext
Access conditionAccess restricted to students and staff of home institution
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:438605
CommitterSanda Hasenay