<p>Cilj istraživanja doktorske disertacije je bio da se u<br />konitnuitetu ispita sadržaj ukupnih fenola, fenolnih kiselina i<br />anitoksidativna aktivnost (antiradikalska aktivnost na DPPH i<br />hidroksil radikale) u toku proizvodnje slada i piva (u ječmu,<br />namočenom ječmu, zelenom sladu, sladu, sladovini, ohmeljenoj<br />sladovini, sladovini tokom fermentacija, mladom pivu i pivu)<br />proizvedenih od tri priznate sorte pivskog ječma: NS 525, NS<br />565 i NS 583.<br />Sadržaj ukupnih fenola u uzorcima ječma je bio: NS 525 -<br />0,76; NS 565 - 0,75 i NS 583 - 0,70 mg GAE/g suve materije.<br />Sadržaj ukupnih fenola u svim proizvednim sladovima (0,96;<br />0,94 i 0,91 mg GAE/g suve materije za NS 525; NS 565 i NS<br />583) je bio viši od sadržaja u ječmu. Sorta NS 525 je imala<br />najviši sadržaj ukupnih fenola tokom svih faza sladovanja, dok<br />su sorte NS 565 i NS 583 imale niže sadržaje ukupnih fenola.<br />Najniži sadržaj ukupnih fenola imala je sorta NS 583.<br />U svim ispitivanim sortama ječma ferulna, p-kumarinska i<br />vanilinska kiselina su bile dominantne u uzorcima ječma,<br />tokom sladovanja i u proizvedenom sladu.<br />Sadržaj ukupnih fenolnih kiselina u ječmu je iznosio za sortu<br />NS 525 - 200,98; NS 565 - 184,10 i za NS 583 – 177,27 μg/g suve<br />materije. Sadržaj ukupnih fenolnih kiselina je rastao kod svih<br />ispitivanih sorti tokom močenja i dostigao maksimum u toku<br />prvog dana klijanja za NS 525 – 548,31; NS 565 – 518,65 i NS<br />583 – 517,17 μg/g suve materije. Dobijeni rezultati su pokazali<br />da je proces sladovanja imao značajan uticaj na sadržaj<br />pojedinačnih i ukupnih fenolnih kiselina.<br />Sorta NS 525 je imala najvišu antiradikalsku aktivnost na<br />DPPH radikale (EC50 za NS 525 - 0,658; NS 565 - 0,667 i NS<br />583 - 0,758 mg/ml) što pokazuje da sorta ječma ima uticaja na<br />antiradikalsku aktivnost na DPPH radikale. Za ispitivane sorte<br />ječma, antiradikalska aktivnost na DPPH radikale se povisila<br />značajno tokom močenja. U proizvedenim sladovima<br />antiradikalska aktivnost na DPPH radikale bila je viša nego u<br />ječmu. Trend porasta i smanjenja antiradikalske aktivnosti na<br />DPPH radikale tokom sladovanja je bio isti za sve ispitivane<br />sorte ječma.<br />Antiradikalska aktivnost na hidroksil radikale, izražena kao<br />EC50 vrednost, u ispitivanim sortama ječma je iznosila: NS 525<br />– 0,352; NS 565 – 0,385 i NS 583 – 0,455 mg/ml. Može se<br />zaključiti da je sorta NS 525 imala najvišu antiradikalsku<br />aktivnost na hidroksil radikale. Antiradikalska aktivnost na<br />hidroksil radikale se znatno povisila tokom močenja. U<br />proizvedenom sladu je antiradikalska aktivnost na hidroksil<br />radikale bila viša nego u ječmu. Trend porasta i smanjenja<br />antiradikalske aktivnosti na hidroksil radikale tokom<br />sladovanja je bio isti za sve ispitivane sorte ječma.<br />Sorta NS 525 je imala najviši sadržaj ukupnih fenola kao i<br />najvišu antioksidativnu aktivnost tj. DPPH i hidroksil<br />antiradikalsku aktivnost. Ovi rezultati pokazuju da sorta<br />ječma može da utiče na antiradikalske osobine slada. Sorta NS<br />525 je imala najviši sadržaj ukupnih fenola, ukupnih fenolnih<br />kiselina i najvišu antiradikalsku aktivnost na DPPH i hidroksil<br />radikale u toku sladovanja.<br />U svim proizvedenim sladovinama, ohmeljenim sladovinama i<br />pivima, ferulna, p-kumarinska, vanilinska i sinapinska kiselina<br />su imale najviše sadržaje. Sadržaj svih ispitivanih fenolnih<br />kiselina je povišen nakon hmeljenja. Najviši ukupni sadržaj<br />fenolnih kiselina je odreñen u ohmeljenim sladovinama (NS<br />525 - 461,41, NS 565 - 426,22 i NS 583 - 423,56 μg/100ml).<br />Sadržaj ukupnih fenolnih kiselina je u svim proizvedenim<br />pivima bio niži u odnosu na odgovarajuće ohmeljene sladovine.<br />U sladovini proizvedenoj iz slada NS 525 je odreñena najviša<br />antiradikalska aktivnost na DPPH i hidroksil radikale što<br />ukazuje da antiradikalska aktivnosti komponenti slada ima<br />uticaja na antiradikalsku aktivnost proizvedene sladovine. U<br />ispitivanim sladovinama, nakon hmeljenja se znatno povisila<br />antiradikalska aktivnost na DPPH i hidroksil radikale.<br />Antiradikalska aktivnost na DPPH i hidroksil radikale se<br />smanjila tokom glavne i naknadne fermentacije.<br />U sladovini proizvedenoj od slada NS 525 sa najvišim<br />sadržajem ukupnih fenola i ukupnih fenolnih kiselina<br />odreñena je najviša antiradikalska aktivnost na DPPH i<br />hidroksil radikale. Tokom proizvodnje piva sadržaj ukupnih<br />fenola se blago smanjio, što ukazuje da je proces proizvodnje<br />imao uticaja na njihov sadržaj. Trend smanjenja<br />antiradikalske aktivnosti na DPPH i hidroksil radikale<br />odgovara smanjenju sadržaja ukupnih fenola i ukupnih<br />fenolnih kiselina tokom procesa proizvodnje piva.<br />Primenjena GC-MS metoda za odreñivanje sadržaja fenolnih<br />kiselina tokom procesa proizvodnje slada i piva se pokazala<br />kao osetljiva, specifična i dobre ponovljivosti. Može se<br />primeniti za odreñivanje sadržaja fenolnih kiselina u ječmu,<br />namočenom ječmu, zelenom sladu, sladu, sladovini, ohmeljenoj<br />sladovini, tokom fermentacije i u pivu.<br />Sadržaj ukupnih fenola, fenolnih kiselina i antioksidativna<br />aktivnost slada, koji se koristi za proizvodnju piva, imaju<br />značajan uticaj na antioksidativnu aktivnost piva.<br />Razumevanje promena sadržaja fenolnih kiselina i<br />antioksidativne aktivnosti tokom proizvodnje slada i piva može<br />nam pružiti vredne informacije o zaštiti endogenih<br />antioksidanata u proizvodnji piva. Na taj način mogu se<br />proizvoditi piva sa višom antioksidativnom aktivnošću i prema<br />tome i povišenom otpornošću prema lipidnoj oksidaciji i<br />starenju piva.</p> / <p>Studies carried out in the frame of the doctorial thesis<br />aimed at continuous determination of the content of<br />total phenolics, phenolic acids and antioxidant activity<br />(antiradical activity on DPPH and hydroxyl radicals)<br />during malt and beer production (in barley, steeped<br />barley, green malt, malt, wort, hopped wort,<br />fermenting wort, green beer, and beer) produced from<br />three accepted brewer’s barley varieties: NS 525, NS<br />565, and NS 583.<br />The total phenolics content in the barley samples was<br />0.76 for NS 525, 0.75 for NS 565 and 0.70 mg GAE/g<br />dry matter (d.m.) for NS 583. Higher content of total<br />phenolics was determined in the malt samples in<br />comparison with the barley samples: (0.96, 0.94, and<br />0.91 mg GAE/g d.m. for NS 525, NS 565, and NS 583,<br />respectively). Variety NS 525 was the highest in total<br />phenolics content during all stages of malting when<br />compared to the other varieties. The lowest content of<br />total phenolics was found in the variety NS 583.<br />In all examined samples, ferulic, p-coumaric and<br />vanillic acid dominated in the barley samples, during<br />malting and in the produced malts.<br />Content of total phenolic acids in the barley samples<br />was 200.98 for NS 525, 184.10 for NS 565 and 177.27<br />mg/g d.m. for NS 583. During steeping, the content of<br />total phenolic acids increased for all samples reaching<br />the maximum at the first day of germination (NS 525 –<br />548.31; NS 565 – 518.65, and NS 583 – 517.17 μg/g<br />d.m.). The obtained results revealed that the malting<br />process had significant impact on the content of total<br />and individual phenolic acids.<br />Variety NS 525 showed the highest antiradical activity<br />on DPPH radicals (EC50 for NS 525 was 0.658, for NS<br />565 0.667, and for NS 583 0.758 mg/ml) indicating that<br />barley variety influences the antiradical activity on<br />DPPH radicals. Antiradical activity on DPPH radicals<br />significantly increased during steeping for all<br />investigated barley varieties. Higher antiradical<br />activity on DPPH radicals was determined in<br />produced malts when compared to corresponding<br />barley varieties. Similar increasing and decreasing<br />trends in the antiradical activity on DPPH radicals<br />during malting were observed in all investigated<br />barley varieties.<br />The antiradical activity on hydroxyl radicals,<br />expressed as EC50 value, in investigated barley<br />varieties, was: 0.325 for NS 525, 0.385 for NS 565, and<br />0.455 mg/ml for NS 583. It can be concluded that<br />barley variety NS 525 showed the highest antiradical<br />activity on hydroxyl radicals. The antiradical activity<br />on hydroxyl radicals significantly increased during<br />steeping. Higher antiradical activity on hydroxyl<br />radicals was determined in produced malts when<br />compared to corresponding barley varieties. Similar<br />increasing and decreasing trends in the antiradical<br />activity on hydroxyl radicals during malting were<br />observed in all investigated samples.<br />Variety NS 525 had the highest content of total<br />phenolics and exhibited the highest antioxidant<br />activity that is antiradical activity on DPPH and<br />hydroxyl radicals. These results suggest that variety<br />can influence the malt antiradical properties. Variety<br />NS 525 was the highest in total phenolics content, total<br />phenolic acids content and antiradical activity on<br />DPPH and hydroxyl radicals during malting.<br />The highest contents of ferulic, p-coumaric, vanillic,<br />and sinapic acids were determined in all wort, hopped<br />wort and beer samples. Increased contents of all<br />phenolic acids were observed after hopping. The<br />highest content of total phenolic acids was determined<br />in the hopped worts (461.41 for NS 525, 426.22 for NS<br />565, and 423.56 μg/100 ml for NS 583. The beers<br />contained less total phenolic acids when compared to<br />the corresponding hopped worts.<br />Wort produced from NS 525 malt showed the highest<br />antiradical activity on DPPH and hydroxyl radicals<br />which indicates that the antiradical activity of malt<br />components affects the antiradical activity in produced<br />wort. After hopping, antiradical activity on DPPH and<br />hydroxyl radicals significantly increased in all worts.<br />The antiradical activity on DPPH and hydroxyl<br />radicals decreased during primary and secondary<br />fermentation.<br />Wort produced from NS 525 malt contained the<br />highest total phenolic content, total phenolic acids<br />content and showed the highest antiradical activity on<br />DPPH and hydroxyl radicals. During beer production,<br />content of total phenolic compounds slightly decreased<br />which indicates that production process had an<br />influence on their content. Similar decreasing trends<br />between the antiradical activity on DPPH and<br />hydroxyl radicals and the contents of total phenolics<br />and total phenolic acids during beer production were<br />observed.<br />The applied GC-MS method for determination of<br />phenolic acids contents during malt and beer<br />production was sensitive, specific and had good<br />repeatability. It can be used for determination of<br />phenolic acids content in barley, steeped barley, green<br />malt, malt, wort, hopped wort, during fermentation<br />and in beer.<br />The content of total phenolics, phenolic acids and<br />antioxidant activity of malt used for beer production<br />have significant influence on the beer antioxidant<br />activity. Understanding how the phenolic acids and<br />antioxidant activity change during malt and beer<br />production can provide valuable information about<br />the protection of endogenous antioxidants in beer<br />production. In this way, the production of beer with<br />enhanced antioxidant activity is possible and therefore<br />higher resistance to lipid oxidation and longer shelflife<br />could be introduced.</p>
| Identifer | oai:union.ndltd.org:uns.ac.rs/oai:CRISUNS:(BISIS)71284 |
| Date | 23 June 2009 |
| Creators | Pejin Jelena |
| Contributors | Grujić Olgica, Čanadanović-Brunet Jasna, Markov Siniša, Pržulj Novo |
| 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 | Unknown |
| Type | PhD thesis |
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