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Author:Hartikainen, Katri
Title:Viljakuidun vaikutus tärkkelyksen tilaan, proteiiniverkon muodostumiseen ja vehnämatriisin reologisiin ominaisuuksiin
Effect of grain fibre on strach pasting, protein network formation and rheological properties of the wheat dough
Publication type:Master's thesis
Publication year:2011
Pages:vii + 76 + [25]      Language:   fin
Department/School:Biotekniikan ja kemian tekniikan laitos
Main subject:Bioprosessitekniikka   (Kem-70)
Supervisor:Leisola, Matti
Instructor:Katina, Kati ; Poutanen, Kaisa
OEVS:
Electronic archive copy is available via Aalto Thesis Database.
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Location:P1 Ark Aalto  2121   | Archive
Keywords:rheology
bran
fermentation
starch pasting
reologia
lese
fermentointi
tärkkelyksen liisteröityminen
Abstract (eng): Addition of fibre increased the nutritional value of the bread but decreases the rheological properties of the dough.
The aim of this master's thesis was to find a connection between added fibre preparation, increased water binding capacity, protein network formation and starch pasting of the dough.
Also, structural changes in bread were studied.
In the literature part, the effects of fibre on dough rheology were reviewed.
In the experimental part, the effect of different fibres on wheat flour and dough's water binding capacity, development time, formation of the wet gluten, viscosity, extensibility and resistance to extension were analysed.
Inulin and native wheat bran (both unprocessed and processed in three different ways) were used as the fibre preparations in this study.
Adding levels for the raw materials were 0%, 10 % and 20%.
The pan bread was baked by straight dough process using each fibre preparation.
The volume and the hardness of the bread on the baking day, after 1 day and after 3 days were measured.

Fermentation of bran with yeast and added enzymes (xylanase, ß-glucanase, and cellulase) has been noticed to increase the volume of the bran bread and soften the bread compared to the bread made of native bran.
With the adding level 20% (fibre content of the bread 6%) the difference in volume compared to ordinary wheat bread wasn't statistically .significant.
When freeze dried, the fermented bran lost all its positive effects on bread, and the end product was small and quite hard compared to the white wheat bread.

A connection between water binding capacity and degradation of the starch pasting level of the fibre-flour-mixes was detected in the PCA and PLS analysis .of the results.
Bran addition decreased the formation of the protein network and pasting of starch.
In literature, other unextractable fibres have been noticed to cause similar effects on dough.
The addition of inulin decreased the rheological properties of the dough more than the addition of bran fibres.
Extensive work will be needed including more studies about the effects of the enzymatically fresh fermented bran on dough rheology; especially on dough expansion, extensibility and CO2 holding capacity.
Abstract (fin): Ravintokuidun lisääminen taikinaan parantaa leivän ravintoarvoa, mutta heikentää taikinan reologisia ominaisuuksia.
Diplomityön tavoitteena oli löytää yhteys taikinaan lisätyn kuituvalmisteen ja jauhon vedensidonnan sekä taikinan proteiiniverkon muodostuksen ja tärkkelyksen liisteröitymisen välillä ja tutkia näiden tekijöiden vaikutusta leivän rakenneominaisuuksiin.
Kirjallisuusosassa luotiin katsaus kuidun vaikutuksiin taikinan reologiassa.
Kokeellisessa osassa analysoitiin kuituvalmisteiden vaikutusta vehnäjauhon/taikinan vedensidontaan, muodostumisaikaan, kostean sitkon muodostumiseen, viskositeettiin sekä taikinan venyvyyteen ja vastustuskykyyn venymiselle.
Tutkimuksessa käytettiin kuituvalmisteina natiivia vehnälesettä. ja kolmella eri tavalla prosessoitua vehnälesettä sekä inuliinia (lisäystasot 0 %, 10 % ja 20 %).
Jokaisella kuituvalmisteella leivottiin vuokaleipä suoraleivontaprosessilla, ja valmiiden leipien tilavuus ja kovuus mitattiin tuoreena sekä 1 ja 3 päivän jälkeen.

Leseen fermentoinnin hiivan ja entsyymilisäyksen (ksylanaasi, ß-glukanaasi, sellulaasi) avulla todettiin parantavan leseleivän tilavuutta ja vähentävän sen kovuutta verrattuna natiivin leseen käyttöön.
Lisäystasolla 20 % (leivän kuitupitoisuus 6 %) tilavuus ei eronnut tilastollisesti merkitsevästi tavallisesta vehnäleivästä.
Fermentoidun leseen pakkaskuivaus hävitti fermentoinnin positiiviset vaikutukset tehden leivästä samankaltaisen kuin natiivista leseestä leivottu leipä eli pienen ja kovan verrattuna valkoiseen vehnäleipään.

Tulosten PCA- ja PLS-analyyseissa havaittiin yhteys jauhokuituseoksen vedensidonnan kasvun ja tärkkelyksen liisteröitymisen heikkenemisen välillä.
Leseiden lisääminen heikensi taikinan proteiiniverkon muodostumista ja tärkkelyksen liisteröitymistä, kuten muidenkin liukenemattomien kuitujen on kirjallisuudessa todettu tekevän.
Inuliinin lisäys heikensi taikinan reologisia ominaisuuksia lesekuitua enemmän.
Jatkotutkimuksia tarvittaisiin tuoreena taikinaan lisätyn entsyymiavusteisesti fermentoidun leseen vaikutuksesta taikinan reologiaan, erityisesti taikinan kohoamiseen, venyvyyteen ja hiilidioksidin pidätyskykyyn.
ED:2011-07-04
INSSI record number: 42605
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