simulation of industrial frying of potato
TRANSCRIPT
Azmil Haizam Ahmad Tarmizi and Razali Ismail Malaysian Palm Oil Board
Lembaga Minyak Sawit Malaysia
Simulation of industrial frying of potato
chips using a pilot plant continuous
fryer: Physico-chemical changes in
palm olein binary blends under
continuous frying conditions
Background of frying
Study case
Design of experiment
Research outcomes
Conclusions
Take home message
Presentation outline
More than 20 million tonnes of edible oil
production is used in frying sectors (Dana and
Saguy, 2006; Gertz, 2004)
Frying is a dehydration process that involves
immersion of food in hot oil when food is heated
above water saturation temperature (Farkas and
others 1996)
Simplicity in frying operation, convenience and
economic viability resulted in extensive sales of
fried food
Frying process
Heat transfer media
Remove water
Unique sensory properties
Impart of fried food
Provide high energy
Modify food texture
Make food palatable
Source of vitamins
Essential fatty acids
Acts as lubricant
Roles of frying
Potato chips
30 – 40%
Tortilla chips
22 – 26%
Frozen French fries
4 – 7%
French fries
12 – 15%
Breaded products
13 – 20%
Battered products
14 – 17%
Instant noodles
18 – 21%
Doughnuts
22 – 26%
How much oil in your favourite snacks?
“...As significant amount of frying
oil is becoming part of the fried
food, oil quality and stability is of
major concern to consumers...”
Naturally stable oils
Breeding
Hydrogenation
Blending
Additives
How to improve oil stability?
Stability of palm olein has extensively
discussed on batch or intermittent frying,
however, limited for continuous frying
The prospect of palm olein for frying
seems to be denied by:
1. misleading perception associated to
saturation level; and
2. strong preference to local oils
Palm olein is known as a heavy duty frying due to its techno-
economic advantages over other oils
Palm olein for industrial frying
Objectives
• To study the stability of palm
olein when blending with (a)
sunflower oil; (b) canola; and (c)
cottonseed oil, respectively;
• To compare (a), (b) and (c) with
that of palm olein as reference
oil (control);
• To investigate the stability of
potato chips up to 4 months of
storage
Expected benefits
• Expose food processors on the
benefits of blending soft oils with
palm olein for industrial frying;
• Increase the market share of
palm olein in countries or regions
that have strong preference to
their locally produced oils
Therefore…
Preparation and experiment setup
Variables Conditions
Fryer capacity 200 L
Frying temperature 180 ± 2 oC
Frying time 2 min
Oil turnover time 8 h
Production 50 kg h-1
Total frying time 40 h (8 h daily for 7 days)
Frying interval Continuous
Oil replenishment Continuous
Filtration Continuous
Oil sampling Interval of 2 h
Product sampling Mid-day daily
Raw materials
Palm olein (PO)
Sunflower oil (SFO)
Canola oil (CNO)
Cottonseed oil (CSO)
Atlantic variety potatoes
Oil blends
60% PO + 40% SFO
70% PO + 30% CNO
50% PO + 50% CSO
Continuous
fryer
Conditioner
Control
panel
Used and fresh oil tanks
Packaging room
Slicer
Air dryer
Pilot plant continuous fryer
Loading Peeling Sorting Slicing and conditioning
Air-drying FRYING Flavouring Packaging
1 2 3 4
5 6 7 8
Frying operation
Analyses
Frying oil
Fatty acid composition
Iodine value
Tocols
Induction period
Colour
Free fatty acids
Smoke point
Peroxide value
p-Anisidine value
Total oxidation
Polar compounds
Polymer compounds
Product
Shelf-life stability
Sensory evaluation
Research outcomes…
Fatty acid composition A
fter
ble
nd
ing
B
efo
re b
len
din
g
C18:3 = 6.20%
C18:3 = 2.14%
Parameter PO SFO CNO CSO PO + SFO PO + CNO PO + CSO
C18:2 / C16:0 0.27 8.76 4.63 2.37 1.16 0.48 1.02
Polyene index 0.25 5.53 3.72 2.05 0.99 0.49 0.89
Iodine value (Wijs) 56.21 112.79 108.65 110.71 85.53 71.68 82.60
Tocols
Frying time (h) Tocols (mg kg -1)
PO PO + SFO PO + CNO PO + CSO
0 587 ± 17 546 ± 15 497 ± 29 523 ± 16
8 475 ± 23 497 ± 5 397 ± 35 461 ± 22
16 393 ± 32 418 ± 11 318 ± 26 484 ± 20
24 414 ± 28 402 ± 9 333 ± 30 378 ± 17
32 394 ± 17 374 ± 19 276 ± 24 323 ± 19
40 401 ± 20 392 ± 18 395 ± 47 305 ± 24
48 393 ± 30 383 ± 18 267 ± 19 352 ± 31
56 379 ± 32 374 ± 15 278 ± 17 327 ± 18
Induction period
Frying time (h) Induction period (h at 110 o C)
PO PO + SFO PO + CNO PO + CSO
0 21.4 ± 1.5 10.6 ± 0.2 11.3 ± 0.9 8.3 ± 0.5
8 15.3 ± 1.0 9.2 ± 0.5 9.1 ± 1.0 7.0 ± 0.3
16 16.1 ± 0.7 8.9 ± 0.2 7.8 ± 0.8 7.5 ± 0.5
24 14.6 ± 0.7 8.9 ± 0.3 5.9 ± 0.5 6.1 ± 0.5
32 15.2 ± 0.6 9.0 ± 0.5 6.2 ± 0.7 4.0 ± 0.4
40 14.6 ± 0.7 8.6 ± 0.2 5.3 ± 0.5 4.3 ± 0.5
48 15.2 ± 0.9 8.7 ± 0.3 5.7 ± 0.6 3.7 ± 0.6
56 14.8 ± 1.1 8.6 ± 0.3 4.9 ± 0.9 3.9 ± 0.5
Colour
Frying time (h) Colour (Redness)
PO PO + SFO PO + CNO PO + CSO
0 2.8 ± 0.2 1.4 ± 0.1 1.2 ± 0.1 2.4 ± 0.3
8 8.3 ± 0.5 4.1 ± 0.1 4.8 ± 0.3 5.2 ± 0.5
16 10.6 ± 0.7 5.1 ± 0.2 8.6 ± 0.4 9.0 ± 0.4
24 11.7 ± 1.1 6.4 ± 0.4 10.3 ± 0.7 11.0 ± 0.1
32 15.5 ± 0.6 6.6 ± 0.3 11.9 ± 0.1 12.6 ± 0.4
40 18.1 ± 0.9 7.2 ± 0.1 12.4 ± 0.4 12.1 ± 0.1
48 19.3 ± 0.5 8.3 ± 0.3 12.0 ± 0.1 12.5 ± 0.5
56 21.2 ± 0.5 9.5 ± 0.3 13.2 ± 0.4 12.8 ± 0.1
Free fatty acid
Smoke point
Total oxidation
Frying time (h) Total oxidation (unit)
PO PO + SFO PO + CNO PO + CSO
0 2.2 ± 0.8 4.2 ± 0.5 8.2 ± 0.7 6.5 ± 0.8
8 33.7 ± 2.5 28.5 ± 1.4 37.7 ± 2.3 33.2 ± 1.6
16 40.8 ± 2.3 40.1 ± 2.3 45.1 ± 1.7 34.7 ± 3.5
24 42.0 ± 4.1 35.5 ± 2.6 55.4 ± 3.7 52.8 ± 4.2
32 43.4 ± 3.0 38.9 ± 2.1 64.5 ± 3.4 65.0 ± 2.9
40 38.5 ± 1.9 42.3 ± 3.5 68.3 ± 5.0 54.1 ± 3.9
48 37.3 ± 4.1 35.9 ± 2.1 63.3 ± 4.4 58.5 ± 3.9
56 40.7 ± 3.9 41.1 ± 2.9 70.9 ± 2.6 63.9 ± 0.5
Polar compounds
Polymer compounds
Shelf life stability and sensory evaluation
In general, the binary mixtures of palm olein with sunflower, canola
and cottonseed oils resulted in comparable oil stability with that of
palm olein under continuous frying conditions
Stability of the oil blends also reflected by acceptable sensory
properties of potato chips even after 4 months of storage
Data generated provides useful information on stable frying oils
without the need to fully replace their local oils
Conclusions
The cost of frying operation is lowered whilst the shelf life of oil is
relatively improved
For more information…
Ahmad Tarmizi AH, Ismail R. 2014. Use of pilot plant scale continuous
fryer to simulate industrial production of potato chips: Thermal
properties of palm olein blends under continuous frying conditions.
Food Sci Nutr (In press).
Ahmad Tarmizi AH, Ismail R. 2008. Comparison
of the frying stability of standard palm olein and
special quality palm olein. J Am Oil Chem Soc
85(3):245-251.
