Transcript ACADEMIC ASPECTS OF WORK PLACEMENT

New and emerging technologies
for whey processing:
“Is there a better whey?”
Alan L. Kelly
Seamus A. O’Mahony
School of Food and Nutritional Sciences
University College Cork, Ireland
Why New Approaches to
Whey Processing?
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•
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Range of technologies well established for whey
processing (centrifugal/membrane separation, ion
exchange, spray-drying, heat treatment)
Increasing awareness of sensitivity of whey components
(i.e., protein) to process variables (e.g., temperature, pH)
Demand for more discriminating and efficient approaches
to whey fractionation and treatment
Novel ways of producing whey
how do we produce whey with different composition/
functionality?
Novel ways of processing whey
how could we process whey to achieve different goals?
Whey processing overview
Raw milk
Pretreatment?
Milk
Separation/fractionation
Casein/
curd
Whey
Pre-processing to stabilise
Drying etc.
Whole
whey
products
Fractionation
Fractionated
Whey
Products
Functional
Food
Ingredients
The production of whey
Raw milk
Pretreatment?
Milk
Separation/fractionation
Casein/
curd
•
•
•
•
Whey
Developments in pre-treatment of milk for cheese-making
or casein manufacture
More and more whey from non-cheese sources
Possible new approaches include casein precipitation by
thermodynamic approaches
Developments in production of ideal or native whey
without complications of rennet, starter, acid addition
The Production of
Ideal Whey?
• Ideal Whey/Native Whey/Virgin Whey/Milk Serum Protein
• Whey stream extracted directly from milk using
microfiltration membranes
• Further processed as per all other whey streams to
produce WPC, WPI etc.
Advantages of Ideal Whey (compared with regular whey):
1. Clean flavour and aroma
2. Low turbidity and good clarity
3. Increased levels of native whey proteins (at least at point
of preparation)
4. Improved protein profile and quality (e.g., GMP, NPN)
The production of
ideal whey
Milk
Microfiltration
Casein
retentate
Whey
Phosphocasein,
WPI,
Cheese etc
WPC etc
Cheese
Whey
Ideal Whey
Starter Culture
Yes
No
Rennet
Yes
No
Glycomacropeptide
Yes
No
Colour
Yes
No
Fat/Phospholipids
Yes
Negligible
2
1
<6.5
>6.6
Pasteurisation Steps
Potential use for colourfree whey production
pH
Colour removal from whey:
a significant challenge
• Choice of approaches
between avoidance
and removal
• End-user preference
is key
• Absorption methods
developed
• Bleaching possible by
a number of chemical
and enzymatic means
• Precipitation by
physico-chemical
means developed
Zhang et al (2013)
Journal of Agricultural and Food
Chemistry, 61, 9230-9240
• Also could combine
alternative colourant usage
with encapsulation
Developments in whey
stabilisation
Raw milk
Milk
Casein/
curd
Whey
Pre-processing
to stabilise
• Cheese whey a very
unstable and dynamic
material
• Curd and fat to be removed
• Coagulant and other (milk
enzymes) active
• Starter present and active
• Heat treatment/separation
typically used to stabilise
The potential of new
technologies for whey
• Whole family of (generally) non-thermal technologies
currently of interest as alternatives to heat treatment
• Some broken through (e.g., high-pressure) to industry;
others at lab scale
• Cost, scale and maturity challenges in many cases
Why might these help?
• Potential for retention of techno-functional or biofunctional properties of whey products while inactivating
undesirable micro-organisms or other agents
• Greater discrimination than heat between sensitivities of
different species/molecules
• Less effect on small molecules than heat
New technologies with
possible applications for whey
Technology
High-pressure treatment
Effects on milk
Possible whey applications
Microbial and enzymatic
inactivation; changes in protein
functionality
Differential protein
High-pressure
Emulsification; microbial
denaturation;
homogenisation
inactivation; enzyme
inactivation
preservation of
biological activities;
Pulsed electric field
Microbial inactivation; changes
treatment
in micelle size and rennet
coagulation
Ultrasound
Inactivation of bacteria and
enzymes
High-intensity light pulses Microbial inactivation
microbial
decontamination
without protein
denaturation
High-Pressure Treatment and
Milk Properties
.
140
Casein micelle size
• Increasingly commercially viable process
• Dramatic and often unique impacts on milk proteins
(caseins and whey proteins)
• Impact on casein micelles of potential interest for
cheese milk treatment/protein functionality manipulation
120
Reduced
lightscattering
100
80
60
40
20
0
0
200
400
600
Pressure (MPa)
800
High pressure and
whey proteins
Denatured b-lg
Complexed
b-lg
Denatured a-la
Relative change (%)
• HPP denatures WP and
incorporates into curd
• Altered protein profile in
whey
140
120
100
80
% Moisture in curd
Curd yield
% Nitrogen in whey
60
40
0
200
400
600
Pressure (MPa)
800
Differences in denaturation of
whey proteins if HP-treated in
milk or whey
• Difference in denaturation
of b-lg if HP-treat milk or
whey
• Potential to tailor whey
protein profile for
functionality
Huppertz et al (2004)
Journal of Dairy
Research, 71, 481-495
• Increasing interest in recovery of
biologically-functional proteins from
whey
• How to achieve microbial stability
without loss of such functionality?
• Potential for use of HPP at tailored
conditions of pH
• Studies of LF stability in whey
under pressure
Buffe Whey Milk
r
400 MPa
Immunoreactive lactoferrin
High pressure and
whey bioactives?
500 MPa
600 MPa
Franco et al (2013)
J. Dairy Res., 80, 128-290
Microbial control in whey
by new technologies
Gallo et al (2007) J. Food Eng. 79, 188Pulsed electric field treatment of
whey combined with nisin usage, in 193
different order of application, for
inactivation of Listeria innocua
Pulsed electric field treatment of
whey shown to protect whey
proteins/lactoperoxidase
De Luiz et al (2009) Milchwissenschaft
62, 422-426
Atamer et al (2014) Frontiers in
Inactivation/removal of lactic acid
bacteria and bacteriophage by non- Microbiology (in press)
thermal methods (e.g., membranes,
UV light)
Developments in whey
fractionation
Raw milk
Continuous development in
membrane materials,
operation and application
Milk
Casein/
curd
Whey
Fractionation
Fractionated
whey
products
Developments in the use of
membrane filtration
Ultrafiltration
Use of charged membranes for tailored
WPC manufacture
MPC manufacture possibilities?
Microfiltration
Sterile filtration (e.g., lactoferrin) or
enrichment of oligosaccharides
Nano-filtration
Integrated whey demineralisation
processes (combined concentration
and partial demineralisation)
Reverse
Osmosis
Pre-concentration of liquid whey
‘Polishers’ for recovery of water from
permeate and evaporator condensate
Whey protein fractionation
using positively-charged UF
membranes
Exploiting differences in isoelectric
point of whey proteins to enhance
rejection at membrane surfaces
Arunkumar and Etzel (2013)
Sep. Purif. Technol., 105, 121-128
Summary and conclusions
1. Whey processing an ongoing area of technological
development
2. Increasing uses of whey and its fractions create
challenges which require novel solutions
3. New technologies may offer new levels of
discrimination between effects
4. Future targets for whey purification??
5. Likely to be significant increase in complexity of
processes and products by 8th IWC.
Many
Thanks!
And…
An
Invitation
to visit
Cork!