Projects per year
Abstract
This study focused on modification of rye bran to produce high fibre extruded cereal foods with a good texture and structure. Rye bran addition during extrusion is challenging due to high levels of insoluble dietary fibre, which leads to less expanded products and a hard texture. Bran modification by particle size reduction or fermentation significantly improved both the structural and textural properties of extrudates. Moreover, optimization of the processing parameters such as increasing the screw speed, lowering the water feed rate, as well as the use of in-barrel hydration regimens further improved the textural properties. The applicability of rye bran in extruded products could thus be improved by particle size reduction and fermentation.
The extruded food structure and texture had a direct effect on the mastication and bolus formation process in the mouth. A hard and dense extrudate structure required more mastication effort than a crispy structure. Crispy and porous structures easily disintegrated in the mouth and produced smaller bolus particles than a hard and dense structure. A smaller particle size of the bolus was associated with increased starch hydrolysis. The bolus particle size was more effective than the matrix composition in
altering the starch digestibility.
Increased dietary fibre intake via appealing snack products could help reduce chronic diseases. Knowledge obtained in this thesis on cereal matrix formation and digestion and the effects of added dietary fibre on the structural and textural properties of extruded solid foams will help the food industry to develop healthy and appealing products. Understanding process-structure-digestibility relationships of high fibre extruded matrices is essential for designing health promoting foods.
The extruded food structure and texture had a direct effect on the mastication and bolus formation process in the mouth. A hard and dense extrudate structure required more mastication effort than a crispy structure. Crispy and porous structures easily disintegrated in the mouth and produced smaller bolus particles than a hard and dense structure. A smaller particle size of the bolus was associated with increased starch hydrolysis. The bolus particle size was more effective than the matrix composition in
altering the starch digestibility.
Increased dietary fibre intake via appealing snack products could help reduce chronic diseases. Knowledge obtained in this thesis on cereal matrix formation and digestion and the effects of added dietary fibre on the structural and textural properties of extruded solid foams will help the food industry to develop healthy and appealing products. Understanding process-structure-digestibility relationships of high fibre extruded matrices is essential for designing health promoting foods.
Original language | English |
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Awarding Institution |
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Supervisors/Advisors |
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Award date | 10 Dec 2020 |
Publisher | |
Print ISBNs | 978-951-51-6857-3 |
Electronic ISBNs | 978-951-51-6858-0 |
Publication status | Published - 10 Dec 2020 |
MoE publication type | G5 Doctoral dissertation (article) |
Note regarding dissertation
To be presented, with the permission of the Faculty of Agriculture and Forestry of the University of Helsinki for public examination in auditorium 1041 of Biocentre 2, Viikinkaari 5, Helsinki, on 10’th December 2020, at 08.00 a.m.Fields of Science
- 416 Food Science
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Research Scientist (PhD Student) @ Biomass and Food Processing, VTT
Alam, S. A. (Participant)
01/01/2014 → …
Project: Research project
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VTT Food Solution: Process induced structural features of solid cereal foam
Alam, S. A. (Project manager)
01/01/2014 → 31/12/2018
Project: Research project
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Research Scientist @ Technologies for Health Promoting Foods, VTT
Alam, S. A. (Participant)
01/01/2012 → 31/12/2013
Project: Research project
Activities
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PhD Grant, 2018 (Raisio Oyj:n Tutkimussäätiön myöntamät apurahat v:lle: Process induced structural features of solid cereal foams
Alam, S. A. (Participant)
1 Jan 2018 → 31 Dec 2018Activity: Other activity types › Prizes and awards - Prizes and awards
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PhD Grant, 2016 (Raisio Oyj:n Tutkimussäätiön myöntamät apurahat v:lle: Process induced structural features of solid cereal foams
Alam, S. A. (Recipient)
1 Jan 2016 → 31 Dec 2016Activity: Other activity types › Prizes and awards - Prizes and awards
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4th International Conference on Food Oral Processing
Alam, S. A. (Attendee)
4 Jul 2016Activity: Participating in or organising an event types › Organisation and participation in conferences, workshops, courses, seminars
File
Prizes
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PhD Grant, 2017 (Raisio Oyj:n Tutkimussäätiön myöntamät apurahat v:lle: Process induced structural features of solid cereal foams
Alam, S. A. (Recipient), 25 Nov 2016
Prize: Prizes and awards