The presentation will focus on the application of the FoodPro® Cleanline enzyme Glycerophospholipid Cholesterol Acyltransferase (GCAT) in the milk, which converts cholesterol to cholesterol esters and lysophospholipids. Lysophospholipids are surface-active amphiphiles that will act as biosurfactants and prevent protein aggregation and promote refolding of proteins (chaperone-like properties), resulting in various processing advantages and increased emulsion stability when used in the manufacture of milk and dairy products. GCAT can reduce free cholesterol in milk by as much as 65 to 85%, which could potentially be an important advantage from a nutritional point of view when producing milk and dairy products.
1. 26 September 2014
Alan Fourie
Senior Application Specialist
DuPont Nutrition and Health SSA
Imagine trouble-free UHT processing for hours and hours!
2. What is FoodPro® Cleanline?
9/25/2014
“The Modification of Milk Surface Properties by
Glycerophospholipid Cholesterol Acyltransferase (GCAT)”
Abstract:
The presentation will focus on the application of the FoodPro® Cleanline enzyme Glycerophospholipid Cholesterol Acyltransferase (GCAT) in the milk, which converts cholesterol to cholesterol esters and lysophospholipids. Lysophospholipids are surface-active amphiphiles that will act as biosurfactants and prevent protein aggregation and promote refolding of proteins (chaperone-like properties), resulting in various processing advantages and increased emulsion stability when used in the manufacture of milk and dairy products. GCAT can reduce free cholesterol in milk by as much as 65 to 85%, which could potentially be an important advantage from a nutritional point of view when producing milk and dairy products.
3. What is your UHT unit performance today?
How often is the UHT system being cleaned per day? What is the cost of cleaning chemical for each cleaning cycle? How many hours/tons of production capacity is lost per day due to production stop for CIP? Any product quality issues like taste or creaming?
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4. What is an enzyme?
›An enzyme is a protein that catalyzes a chemical reaction
›Works by selectively binding to substrate
›Enzyme reactions are less energy consuming and create much less waste compared to reactions using chemicals
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5. ›Temperature
•Each enzyme has an optimum/ideal temperature which leads to highest number of enzyme/substrate interactions
›pH
•Each enzyme has an optimum/ideal pH which leads to highest number of enzyme/substrate interactions
›Inhibitors and activators
•Enzyme inhibitors are molecules that bind to enzymes and decrease their activity
›Enzyme concentration
›Substrate concentration
What influences enzyme activity
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6. Acyltransferase
FoodPro® Cleanline
O
O
CH3
O
P
OH
O
O
N
+
CH3
CH3
CH3
+ OH
Lyso-phospolipid (enzyme modified phospholipids)
Phospolipid
(phosphatidylcholin)
Cholesterol
Cholesterolester
+
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9 14
10 8
17
12
11
15
16
5 7
6
20
CH3
18
CH3
1 19
23
22
4
24
2
3
H
H
H
H
HO
CH3
CH3
H3C
+
Enzyme reaction with acyltransferase in milk
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13
9 14
10 8
17
12
11
15
16
5 7
6
20
CH3
18
CH3
1 19
23
22
4
24
2
3
H
H
H
H
O
CH3
CH3
H3C
O
H3C
O
O
O
CH3
O
CH3
O
P
OH
O
O N
+
CH3
CH3
CH3
7. Why this new development?
During the production of UHT milk, the heating surface of the heating unit foul due to
build up of proteins and sugars and minerals from the milk
This results in pressure building in the system and reduced heat transfer. When the
pressure becomes too high and the heat transfer is reduced, the unit needs to be
cleaned
This can also result in burnt taste of the UHT milk
Cleaning and sterilisation takes time, up to 2 hours, and takes significant amounts of
cleaning compounds
This can lead to:
Not meeting overall performance on capacity, cost and quality
High costs for cleaning: hours spent and chemicals consumed
Product rejection due to taste
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8. Without FoodPro ® Cleanline,
After 11 hours run time
With FoodPro ® Cleanline,
Milk enzymation 15 ppm 6 – 8 hours at 5°C ,
After 15 hours run time
Industrial scale trials in tubular heat equipement, plant capacity 13 000 L/hour
Effect of FoodPro® Cleanline on fouling
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9. Fouling of heat exchangers in the dairy industry is a quite severe problem, both technically and economically.
During a normal working cycle, the heat exchanger is subject to undesired material accumulation along its working surfaces, normally referred to as Fouling.
Fouling formation causes increased pressure drop over plate heat exchangers, and also leads to reduced heat transfer and thereby increased energy consumption.
Result: loss of production capacity as well as increased costs for manpower,
energy and detergent consumption during processing and cleaning.
The enzymatic treatment of milk will greatly reduce fouling rates
Effect of FoodPro® Cleanline on fouling
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10. Effect of FoodPro® Cleanline on fouling
Development of pressure drop in commercial UHT plant
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2
4
6
8
10
12
14
16
1
2
3
4
5
6
7
8
9
10
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20
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Hours
Pressure drop (bar)
Enzymated UHT r.milk
Non Enzymated UHT r. milk
Pre-set CIP limit
3 day average from full scale production run
Recombined milk. Dosage 10 ppm, 45-100 minutes at 40°C. Observed conversion rate of Cholesterol to Cholesterol-ester 82%
›Fouling can be expressed by an increase in backpressure over the heat exchanger
›Acyltransferase reduces the increase in pressure drop
›Production cycles are extended 4 to 6 hours before CIP is needed
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›Native phospholipids always form lamellar bi-layers and cholesterol is commonly found in biological membranes (native milk fat globules being a typical example)
›Cholesterol-esters are, like triglycerides, entirely hydrophobic and thus do not play a role in membrane formation like cholesterol normally does
›Lyso-phospholipids are less hydrophobic than phospholipids and, therefore, can more readily associate with hydrophobic amino acids in denaturated whey proteins, and have a better ability to bind proteins to the interphase between fat and water
›Lyso-phospholipids prevent protein aggregation and promote refolding of proteins* (chaperone-like properties)
›These functions will impact the accumulation of denatured proteins on hot surfaces (fouling)
* Biochemical and Biophysical Research Communications 289, 1268–1274 (2001)
The theory behind the anti-fouling effect
12. Plate heat exchanger
Fouling on heat exchanger
Clean heat exchanger
Fouling may vary depending on UHT Plants
Tubular heat exchanger We expect FPCL will be more efficient in an indirect system where fouling accumulates on the exchange surfaces (e.g. equipment where there is no direct contact between the product and the heating media, such as plate or tubular heat exchangers)
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13. Practical experience with FoodPro® Cleanline : increased run-time
Dosage 10 ppm, 2-14 hours at 4°C.
Trials repeated 6 times always with more than doubling of possible run- time.
Observed 40-45% reduction of organic material in CIP water after enzymated product compared to reference
Pilot scale trials with condensed milk (UHT)
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0
2
4
6
8
10
12
14
16
Reference
Enzymated
Run time (hours)
Run time
14. Emulsion stability effect of FoodPro® Cleanline
Enzymation of milk with FoodPro ® Cleanline will decrease the surface tension and thereby increase the efficiency of the homogeniser Increased protein incorporation in the fat globule membrane will increase resistance against coalescence, without increased tendency to flocculation
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Creaming of UHT-milk is reduced by FPCL treatment
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Enzyme addition recommendation
Enzyme dosage depends on process time and temperature.
2 main recommendations:
Addition to the retention tank, after fat standardisation, at 5-10°C. Enzyme reaction for 2 hours minimum and up to 36 hours before UHT treatment. Enzyme dosage 10-12 ppm
For recombined milk: Enzyme addition at 40-50°C in the recombination tank.
Enzyme reaction for 30 minutes minimum and up to 4 hours, prior to UHT treatment.
Enzyme dosage 4-6 ppm
16. FoodPro® Cleanline potential benefits:
•Higher factory output
•Labor cost savings
•Lower cleaning chemical costs
•Less quality issues
•Higher sales because of a better tasting product
•Fewer complaints on creaming
•Easy to implement (no investment needed)
•Reduced environmental impact (water, CO2 and chemicals)
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17. What is your potential value? Example:
Example : Dairy working 300 days/year, 24 hours/day, production capacity 13000 liters/hour. 2 CIP/day of 2 hours each. Possibility to go down to 1 CIP/day when using FoodPro® Cleanline
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18. FoodPro® Cleanline
FEATURE
Modification of milk phospholipids
POTENTIAL BENEFIT
Reduced fouling
Reduced consumption of energy, water & chemicals
Reduced organic material in waste water
Reduced creaming
POTENTIAL GAIN
Higher factory output, higher profits
Reduced costs (labour, chemicals, energy, recycling)
Reduced environmental impact
Increased market share/customer satisfaction
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