effect of bioprocessing on texture of high fibre snack ... · dammann et al. 2013, consumption and...
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Effect of bioprocessing on texture of high fibre snack productsSAAFOST 2019Markus Nikinmaa
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1. Short overview of VTT2. Importance of dietary fibre3. Effect of high DF on texture of snack foods4. Bioprocessing approaches to improve texture of food
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Owned by
Ministry of
Economic
Affairs and
Employment
VTT – beyond the obvious
VTT – beyond the obvious
Established in
1942
268M€Net turnover and
other operating
income (VTT
Group 2018) 2,049
Total of personnel
(VTT Group
31.12.2018)
44%From the net
turnover abroad
(VTT Group
2018)
31%Doctorates and
Licentiates
(VTT Group
2018)
VTT is one of the leading research, development and
innovation organizations in Europe. We help our customers
and society to grow and renew through applied research. The
business sector and the entire society get the best benefit
from VTT when we solve challenges that require world-class
know-how together and translate them into business
opportunities.
Our vision
A brighter future is created through science-based
innovations.
Our mission
Customers and society grow and renew through
applied research.
Strategy
Impact through scientific and technological excellence.
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VTT’s status
as performer
of R&D work
BASIC
RESEARCH
Universities
APPLIED
RESEARCH
VTT
DEVELOPMENT
Industry
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Smart food
production4.0
Consumer 4.0
Agile consumer-centric
food manufacturing
Food 4.0
Sustainable food
ingredients
Food Economy 4.0 – strategic focus points of VTT food research
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Dietary fibre & health
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Intake of DF correlates with reducedrisk of heart disease, cancer and diabetes 2
▪ Yet intakes are far below recommendations 25-38 g in many
parts of the world
• Finland: 66 % of population below (average: women 20 g/day, men 22
g/day) (Finravinto-study 2017)
• South Africa: Dietary Fiber Intake and Metabolic Syndrome Risk
Factors among Young South African Adults (Sekgala et al. 2018)
• ” More than 97% of participants had fiber intakes below the
recommended levels.”
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Why do people consume too little fibre(Dammann et al. 2013)?
▪ Lack of knowledge and unfamiliarity
• about importance from a health perspective
• about what foods contain fibre
▪ Availability of high DF products
▪ Sensory aspects (mouthfeel and taste)
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Improving sensoryattributes of bran enrichedand wholegrain foods
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Sensory challenges related to high brancontent (Heiniö et al. 2016):
▪ Hardness
▪ Coarse, harsh mouthfeel
▪ Bitterness, Astringency
▪ Grainy taste
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100 % ryeendospermflour
40 % bran60 % ryeendospermflour
Nikinmaa et al. 2017
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What causes the negative effects?
▪ Coarse texture due to bran particles
▪ Impaired structure formation due to a variety of factors (Robin et al 2011)
• Dilution of structure forming components, e.g. starch
• DF affects available water for e.g. starch and gluten
• Effect on rheological properties of matrix
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Bioprocessingapproaches for high DF snack foods
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Bioprocessing to improve DF functionality
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When?• Ingredient
manufacturing
• Food
manufacturing
How?• Enzymatic
• Fermentation
• Thermo-
mechanical
Why?To improve • technological quality
• sensory quality
• nutritional quality
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Lactic acid bacteria (LAB) fermentationfor high fibre extruded snacks
▪ Used for thousands of years in sourdough fermentation, pickling
etc. to create flavour, improve texture and prolong the lifespan of
foods
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LAB fermentation improved expansionand texture of rye bran supplementedextrudates
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Chemical pH reduction of rye branimproved its extrusion behaviour▪ pH adjusted to the same pH as fermentations at 0, 10 and 15 h
▪ End pH 4.2
▪ 32 % of rye endosperm flour replaced with bran
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0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
Control Fermented Chemicallyacidified
Cri
spin
ess
ind
ex
Har
dn
ess
(N)
Hardness Crispiness index
380.00
400.00
420.00
440.00
460.00
480.00
500.00
Control Fermented Chemically acidified
Rad
ial e
xpan
sio
n (
%)
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Chemical pH adjustment caused similardegree of fibre and protein hydrolysis
▪ Fibre content in extrudats was slightly reduced by fermentation
and pH reduction (control 18.7 % → acidified samples 17.2% and
fermented sample 17.3 %)
▪ Protein was solubilised, soluble protein content increased from 8
% to 11 %. Smaller protein particles visible in microscopy.
▪ The effect was most likely because of activation of xylanolytic and
proteolytic enzymes that has also been observed in
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Control Fermented
Chemicallyacidified
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Example of enzymatic treatment on wholegrain crackers
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▪ Wholegrain wheat flour crackers
▪ Flours treated with xylanolytic and
proteolytic enzymes prior to baking
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Xylanase and protease treatmentimproved texture of wholegraincrackers
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0
5
10
15
20
25
30
35
40
45
Control Xylanase 10x Fungalprotease 10x
Xylanase 10x +Fungal
protease 10x
Thic
knes
s o
f 5
cra
cker
s (m
m)
0
2
4
6
8
10
Control Xylanase 10x Protease 10x Xylanase 10x +Protease 10x
Sen
sory
sco
re (
0-1
0, n
=10
)
Hardness Crispness
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Conclusions
▪ Texture and structure of high DF snack foods can be improved by
fermentation or enzymatic treatment while retaining the high DF
content.
▪ Crispy and expanded extrudates with up to 20 % DF could be
produced
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References▪ Dammann et al. 2013, Consumption and consumer challenges of wholegrain foods, in Fibre-rich
and wholegrain foods. Ed. Delcour J., Poutanen K.
▪ Heiniö et al. 2016, Sensory characteristics of wholegrain and bran-rich cereal foods: A review,
Trends in Food Science & Technology 47
▪ Nikinmaa, M., Alam, S. A., Raulio, M., Katina, K., Kajala, I., Nordlund, E., & Sozer, N. (2017).
Bioprocessing of bran with exopolysaccharide producing microorganisms as a tool to improve
expansion and textural properties of extruded cereal foams with high dietary fibre content. LWT -
Food Science and Technology, 77, 170–177. https://doi.org/10.1016/j.lwt.2016.11.041
▪ Nikinmaa, M., Mattila, O., Holopainen-Mantila, U., Heiniö, R. L., & Nordlund, E. (2019). Impact of
lactic acid bacteria starter cultures and hydrolytic enzymes on the characteristics of wholegrain
crackers. Journal of Cereal Science, 88(November 2018), 1–8.
https://doi.org/10.1016/j.jcs.2019.04.016
▪ Robin, F., Théoduloz, C., Gianfrancesco, A., Pineau, N., Schuchmann, H. P., & Palzer, S. (2011).
Starch transformation in bran-enriched extruded wheat flour. Carbohydrate Polymers, 85(1), 65–
74. https://doi.org/10.1016/j.carbpol.2011.01.051
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