Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Make your likes visible on Facebook?

Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.

No, thanks

Copy of Copy of HY-white 0.1.1

Design elements for presentations - University of Helsinki / Helsingin yliopisto
by

weijing wu

on 13 March 2015

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Copy of Copy of HY-white 0.1.1

GELLING PROPERTIES OF OAT PROTEIN DEAMIDATED BY PROTEIN GLUTAMINASE
Weijing Wu
M.Sc. Food Science
Cereal Technology Group

Supervisor:
Hannu Salovaara
Tuula Sontag-strohm
and Zhongqing Jiang

Background
Oat protein fraction used in experiment
HELSINGIN YLIOPISTO
HELSINGFORS UNIVERSITET
UNIVERSITY OF HELSINKI

Faculty of Agriculture and Forestry/Weijing Wu/Gelling properties of oat protein deamidated by by protein glutaminase
www.helsinki.fi/yliopisto
10.01.2013
Design and Methods
Schedule
Overview
Gelling properties of oat protein deamidated by protein glutaminase (PG)
Oat (Avena Sativa)
* Fodder
* Food
Food products of oat
Oat grain bar
Rolled oat
Quick oat porridge
Oat crisp
Oat bread
Characteristics of oat products
(1) Based on starch and beta-glucan
(2) Low protein concentration
Nutritional value of oat protein
* High content (15-20%)

*Balanced amino acid content
*Digestibility ≈ 90%
*Biological value ≈75%
Protein glutaminase (PG)
>A novel enzyme
>Safe for food application.
PG on oat protein functionalities
Secondary structure

flexibility
Yogurt protein gel
Cow or soy Milk+Lactic acid bacteria(LAB)
Acid-induced protein gel
Soybean yogurt
Cow milk yogurt
Fig. Process flow chart of oat dry fractionation
Side-product
of beta-glucan concentration
Native oat protein
PG Deamidation
Gel formation
Evaluation of gel
Experiment Schedule
*Rheological analysis
*Microscopy

Gel structure properties
Dynamics oscillation
Rheometer
Rheology
Rheology describes the
deformation
of a body under
stress
.
Ideal solids
Ideal fluids
Viscoelastic
Cone-and-plate sensor system
Thixotropy
Upward curve : thinning under increasing shear rate
Orientation of flow > Brownian movement of molecules
Fermentation
Processing of yogurt
Gelling properties
Protein Gel in food
Boiling
Milk
Heat
Denaturation
pH ≈ pI
Fermentation until pH 4.3-4.8
Addition of starter
Yogurt
Change of protein
Fig. Deformation of solid body
Weak bonds: hydrogen bond and ionic bond
Thixotropic liquid is defined
potential reformation
of gel structure.
Thixotropy
Protein gel structure in common in food.
Cheese
Tofu
Yogurt
Egg protein gel
Protein-gel
is a
continuous network
consists of
unfolded protein
molecules with
a certain degree of order
.
Homogenization
Lactic acids
Soybean
globulin
Casein
and whey protein
vs.
Similar

solid-like gel characteristic
Yogurt-like product
Oat milk
Oat protein
>Nutrition
>Composition
>Functional properties
>Physical and chemical properties
Good for human health
Composition of oat protein
Denaturation temperature
*Solubility -
poor!
*Emulsifying properties-
*Foaming properties-
bad
Gelling properties
Yogurt is
pseudoplastic liquids
Analysis of dynamic oscillation
Imput:
Measurement :
G'
Elasticity---storage modulus
Viscosity---loss modulus
No damage to gel structure
Concept:
(1)If G’ >G’’ in different frequency sweep, it represents the solid-like properties.

(2) The higher value of G', the stronger gel is.
Continuous shear flow test (Rotation)
Example:
Scanning electron microscope (SEM)
Example: microscopy picture of yogurt
Microstructure of yogurt
Protein gel network
Thanks for your attention.
Questions
Oat globulin 110 C
Oat albumin 87 C
Isoelectric point
Rice : 73-82 C
Soybean: 78-90 C
Red bean: 82-92 C
Other grain protein
Wheat: 70 C
pI = pH 4-6
Protein solubility at neutral condition (pH 7)
Oat: 23%
Soybean: 97%
Unstable emulsion!
Emulsifying properties
Foaming properties
Bad Foaming properties!
Aims
(1) to study
gelling ability
of PG deamidated oat protein;

(2) to study
physical properties
of
gel
made of PG deamidated oat protein
Aims:
Reduce pH
Thermal coagulated of oat globulin (Ma and Harwalkar, 1987)
Gelling properties of oat protein
Yogurt
Gel: Elasticity
Fluid: Viscosity
Master Thesis Schedule
References
Alfonso Totosaus, Jose G. Montejano, Juan A. Salazar and Isabel Guerreo. (2002). A review of physical and chemical protein-gel induction. International Journal of Food Science and Technology(37): 589-601.
Anne Saint-Eve, Alexandre Juteau, Samuel Atlan, Nathalie Martin, and Isabelle Souchon. 2006. Complex viscosity induced by protein compostion variation influences the aroma release of flavored stirred yogurt. J. Agric. Food Chem.(54):3997-4004.
C, -Y. MA. 1983.Chemical characterization and functionality assessment of protein concentrates from oats. Cereal Chem. 60 (1): 36-42.
Ching-Yung Ma, Ghanikhan Khanzada, and Ventesh R. Harwalkar. 1988. Thermal Gelation of Oat Globulin. J. Agric. Food. Chem. (36): 275-280
Franzen KL, Kinsella JE. 1976. Functional properties of succinylated and acetylated soy protein. Journal of agricultural and food chemistry. (4):788-95.
Gebhard Schramm. 1998.A Practical Approach to Rheology and Rheometry. Gebrueder HAAKE GmbH, Karlsruhe, Federal Republic of Germany.
Mirmoghtadaie L, Kadivar M, Shahedi M. 2009. Effects of succinylation and deamidation on functional properties of oat protein isolate. Food Chem. 114(1):127-31.
O. Sandoval-Castilla, C. Lobato-Calleros, E. Aguirre-Mandujano, E.J. Vernon-Carter. 2004. Microstructure and texture of yogurt as influenced by fat replacers. International Dairy Journal (14): 151-159.
Peterson M. David. 1978. Subunit structure and composition of Oat Seed Globulin. Plant Physiol(62): 506-509.
Y.H. Cho, J.A. Lucey, H. Singh.1999- Rheological properties of acid milk gels as affected by the nature of the fat globule surface material and heat treatment of milk. 9(8):537-545.
www.malvern.com/
www.FAO.com
www.VTT.fi
References
(Ma, 1983)
(Ma, 1983)
(Ma, 1983)
(Mirmoghtadaie et al. 2009)
(Franzen and Kinsella, 1976)
(Zhongqing Jiang Master Thesis, 2012)
(Saint-Eve et al. 2006)
(Sandoval-Castilla, 2004)
(Totosaus et al., 2002)
(Adjusted from Lee and Lucey, 2010)
(Adjust from Cho, 1999)
Fig. Shear stress changes as a function of shear rate
(From Mavern Instruments Limited)
Oscillate back and forward
Modulus: Stress/Strain
G'
G''
G''
Soy protein has also good gelling capacity.
Important !
o
Solubility-pH profile
bad
Gelling properties
Typical example:
> Good for health
Example: YOSA

per 100 g
Protein
1,1 g
Carbohydrates
10 g
Example: oat milk
per 100 ml
Protein
1 g
(Hoseney, 1994&Ma, 1983)
(Ma ,1983)
Solubility
pH
o
o
o
o
o
Limited !
High temperature. Hard gel. Difficult to compare.
Lack of knowledge!
Protein glutaminase (PG)
Solubility
Emulsion qualities
(Schramm,1998)
Elasticity
Viscosity
Cone
Plate
Smaple
Gap
Useful to reveal the gel structure
Stress
Strain
Yogurt
Full transcript