The quality of Finnish oats is excellent. In his PhD thesis, Juhani Sibakov,
MSc (Tech), developed methods to broaden the use of oats in, for example,
snacks and beverages. Fractions with 56% beta-glucan and 73% protein were
obtained. The fractionation process developed at VTT was scaled up in Germany
together with NateCO2 GmbH and Hosokawa Alpine AG.
VTT’s research scientist Juhani Sibakov developed oat fractions with up to 56%
beta-glucan content for food and nutraceutical products. This is the highest
content ever reached by a method without any water or solvents. In the
beginning of the process, oats were defatted by supercritical carbon dioxide
extraction. From the defatted oats, it was then possible to separate highly
enriched beta-glucan fractions. Several processing steps were required to
obtain such a high content of beta-glucan, and thus the yield of this fraction
was just a few per cent.
A beta-glucan content of
approximately 35% was achieved using only dry grinding and air classification.
This kind of beta-glucan fraction could be an interesting ingredient for the
food processing industry because its yield was approximately 8-10% from the
oat raw material.
The separation process developed at VTT was
scaled up to industrial scale in Germany, and it is expected to be
commercialised within the next few years.
A highly enriched
protein fraction was also separated with the same separation method. The
protein content of this fraction can be as high as 73%. The oat protein
fraction is an interesting option for other plant-based proteins. The use of
oat protein in different food applications is currently being studied at VTT.
Beta-glucan
for beverages and snacks
When untreated beta-glucan is
added to beverages, it gives them a slimy texture, which is typical of oat
porridge. In the PhD work, this sliminess was avoided by hydrolysing the
beta-glucan molecules in a controlled way with acid or enzymes. The
enzymatically hydrolysed oat bran turned out to be more interesting because it
allowed 1.5 g of beta-glucan to be included in a beverage of 100 mL, which
retained its low viscosity for much longer than the acid hydrolysed version.
The
production of expanded oat snacks is challenging due to their high lipid
content. This work was the first to use only oat-based ingredients for
well-expanded products. The water-soluble oat fibre improved the expansion,
whereas the addition of water-insoluble oat fibre led to less expanded and too
hard a texture. The snack containing water-soluble fibre had up to 11%
beta-glucan content. The extruded snacks based on defatted oats tasted
pleasant and were stable at room temperature.
VTT also has an
on-going project aiming at the commercialisation of two patents related to
beta-glucan in beverage applications.
Finland as an oat
producer
Finland is the world’s fifth largest oat
producer with approximately 1.2 billion kg of oats per year. Finnish oats are
of primary quality because oats require a long cultivation season and a cool
climate.
VTT has studied oats for almost 40 years, and most
of the patents related to oat fractionation have been filed by employees of
VTT.
Health claims
The European Union
accepted two health claims for beta-glucan, the soluble fibre of oats, last
year. Beta-glucan helps to control blood cholesterol and attenuates the peaks
in blood glucose after a meal. In addition, the insoluble fibres improve the
wellbeing of the stomach and gut.
VTT’s Research Scientist
MSc Juhani Sibakov will defend his dissertation “Processing of oat dietary
fibre for improved functionality as a food ingredient” on 31st October at
Aalto University, with prof. Thava Vasanthan from University of Alberta as
opponent.
MEDIA MATERIAL
PHOTO: Oat snacks (photographed
by Antonin Halas).
PHOTO:
Juhani Sibakov
Link
to the electronic version of the PhD thesis
