Non-thermal technologies for nutritional and technological improvement of oat and barley in flat bread

doctoral thesis

• Title (croatian): Netoplinske tehnologije za poboljšanje nutritivnog i tehnološkog potencijala zobi i ječma u tankom kruhu
• Author: Tomislava Grgić
• Mentor: Dubravka Novotni (mentor)
• Committee member: Nikolina Čukelj Mustač (predsjednik povjerenstva)
• Committee member: Tomislava Vukušić Pavičić (član povjerenstva)
• Committee member: Sanda Vladimir-Knežević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Cereal Chemistry and Technology); Zagreb
• Defense date and country: 2024, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology
• Universal decimal classification (UDC): 664 - Production and preservation of solid foodstuffs

Abstract

Oats and barley milling products are a rich source of dietary fiber, especially β-glucans, but also possess high enzyme activity, contain antinutrients, and undesirably affect the technological and sensory properties of the bakery products. This dissertation investigated the pretreatment of oat and barley flour/bran using traditional (sourdough fermentation) and innovative techniques (high-intensity ultrasound, pulsed electric field) and the application of these pretreated raw materials in making flat bread. The addition of oat/barley bran improved the fermentation of flour to sourdough, which successfully slowed down the enzymatic browning of the retarded dough and reduced antinutrient content (32-38%) in flat bread. Ultrasonic pretreatment of oat and barley bran partially inactivated β-glucanase (by 82% and 55%), reduced antinutrients (by 17% and 39%) and increased the β-glucans content (25-65%) in the flat bread. Processing of oat and barley flour with a pulsed electric field also reduced its β-glucanase activity (by 77% and 40%), improved the solubility of non-starch polysaccharides, and increased the β-glucans content in flat bread (21-32%). These innovative and traditional techniques, in combination or individually, improved the techno-functional properties of flour/bran by enabling fiber enrichment, improving texture profile, while maintaining consumer acceptance of flat bread.

Abstract (croatian)

Zob i ječam bogat su izvor prehrambenih vlakana, posebice β-glukana, međutim posjeduju visoku enzimsku aktivnost, sadrže antinutrijente te nepoželjno utječu na tehnološka i senzorska svojstva pekarskih proizvoda. U ovoj disertaciji istražena je prethodna obrada zobenih i ječmenih posija te brašna tradicionalnim (fermentacija kiselog tijesta) te inovativnim tehnikama (ultrazvuk visokog intenziteta, pulsirajuće električno polje) te primjena tako obrađenih sirovina u izradi tankog kruha. Dodatak zobenih/ječmenih posija poboljšao je fermentaciju brašna u kiselo tijesto, što je uspješno usporilo enzimsko posmeđivanje tijesta tijekom procesa odgođene fermentacije i smanjilo sadržaj antinutrijenata (32-38%). Prethodna obrada zobenih i ječmenih posija ultrazvukom visokog intenziteta rezultirala je djelomičnom inaktivacijom endogene β-glukanaze (za 82% i 55%), smanjenim udjelom antinutrijenata (za 17% i 39%) i povećanim udjelom β-glukana (25-65%) u tankom kruhu. Obrada zobenog i ječmenog brašna pulsirajućim električnim poljem rezultirala je smanjenjem β-glukanazne aktivnosti (za 77% i 40%), poboljšanom topivosti neškrobnih polisaharida te povećanim udjelom β-glukana tankog kruha (21-32%). Ove inovativne i tradicionalne tehnike, u kombinaciji ili zasebno, poboljšale su tehno-funkcionalna svojstva brašna i posija, omogućujući obogaćivanje vlaknima, poboljšanje teksture tankog kruha, uz zadržavanje senzorske prihvatljivosti potrošača.

• Keywords: barley; bran; flat bread; high-intensity ultrasound; non-starch polysaccharides; oat; pulsed electric field; sourdough fermentation; β-glucanase
• Keywords (croatian): fermentacija kiselog tijesta; ječam; neškrobni polisaharidi; posije; pulsirajuće električno polje; tanak kruh; ultrazvuk visokog intenziteta; zob; β-glukanaza
• Language: english
• URN:NBN: urn:nbn:hr:159:792812
• Promotion: 2024
• Study programme: Title: Postgraduate PhD Study in Nutrition; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/ doktorica znanosti, područje biotehničkih znanosti, odgovarajuće polje (određeno matičnom strukom) (doktor/ doktorica znanosti, područje biotehničkih znanosti, odgovarajuće polje (određeno matičnom strukom))
• Type of resource: Text
• Extent: 196 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-06-18 09:31:43