FRYING OILS AND HEALTHFRYING OILS AND HEALTH

I Oxidative stressed frying fats and oilsI. Oxidative stressed frying fats and oilsII. Potential role for healthIII. Nutritional effect of fryingIII. Nutritional effect of frying

Nik l K A d ik lNikolaos K. AndrikopoulosEmeritus Professor of Harokopio University

70 El. Venizelou Ave., Kallithea, Athens, Greece e mail: nandrikop@hua gre-mail: nandrikop@hua.gr

PART ONEPART ONE

OXIDATIVE STRESSED FRYINGFATS AND OILSFATS AND OILS

F.O.H. 2

What is frying ?What is frying ?  

One of the most popular methods for food preparationOne of the most popular methods for food preparationIt affects several organoleptic characteristics regarding

lcolortastetexture

F.O.H. 3

What is frying ?  

The oil is a heat transfer medium, it is absorbed by the food d b f diand becomes part of our diet

h l f f d f d d d h l d fThe quality of fried food depends on the quality and type of the oil used

The beneficial effect of frying on the organoleptic properties of the food is accompanied by adverse changes in physicalof the food is accompanied by adverse changes in physical characteristics of the oil

F.O.H. 4

Changes during frying

F.O.H. 5

Changes during frying

Food+ frying oil + air + (O2) + heating

natural phenomena(aeration, evaporation,Foaming etc.)

Chemical reactions

hydrolysis, autoxidation,dehydration, polymerization,

cycling etc.

Changes:viscosity, density, cycling etc.conductivity, staining, etc.

Production of by products: ΤPM(total polar materials)

Some have been accused foradverse actions

Higher Market Police limits

F.O.H. 6

Higher Market Police limits

Deteriorated fried oil and fat products

Total Polar Materials (TPM)

M d di l idMono‐ and di‐glycerides

Free Fatty Acids (FA)

Dimeric and polymerized FA

Dimeric and polymerized triglycerides (PTG)

Other?

3rd Int. Symp. DGF. Eur. J. Lipid Sci. Technol. 102 (2000)

EEC limits for TPM:         25 – 27% for rejection,      20% for replenishmentEEC limits for PTG:                   12 % for rejection,     10% for replenishment

F.O.H. 7

Oxidative and degradated products of TPMOxidative and degradated products of TPM

Volatiles (low MW)

Ali h i ld h d ( l di l )Aliphatic aldehydes (‐enals, ‐dienals)

Aliphatic cetones

Epoxides

Hydrocarbones

Cyclic structures

Other?( l l h d b )(polycyclic aromatic hydrocarbons, …..)

3rd Int. Symp. DGF. Eur. J. Lipid Sci. Technol. 102 (2000)y p p ( )

F.O.H. 8

Oxidative and degradated products of TPMOxidative and degradated products of TPM 

Non‐volatiles

Triglyceride hydroperoxides (not present in the frying bath)Triglyceride hydroperoxides (not present in the frying bath)

“Aldehydic” triglycerides containing attached oxo‐, hydroxy‐,epoxy cyclic acidsepoxy‐, cyclic acids

Aldehydes (‐enals, ‐dienals, …)  of medium MW (2,4‐decadienale )decadienale,...)

Other? (acrylamide, heterocyclic aromatic amines)

3rd Int Symp DGF Eur J Lipid Sci Technol 102 (2000)3rd Int. Symp. DGF. Eur. J. Lipid Sci. Technol. 102 (2000)

F.O.H. 9

Which TPM degradation‐fraction(s) are theWhich TPM degradation fraction(s) are themost suspicious for health damage(s)?

Cyclic fatty acids

“Aldeh dic” trigl ceridesCytotoxic, hepatotoxic,

i i i“Aldehydic” triglycerides

Triglyceride hydroperoxides

carcinogenic, mutagenic effect(s) on exp. animals

Aldehydes, cetones, … Acrylamide

Heterocyclic aromatic aminesHeterocyclic aromatic amines

Polycyclic aromatic hydrocarbons

O h ?Other?

Reviewed by G. Billek, Eur. J. Lipid Sci. Technol. 102 (2000) 587‐593y p ( )

F.O.H. 10

Oil uptake by fried foods

Product % Oil

Potato chips 34 6Potato chips 34,6

Corn chips 33,4

Tortilla chips 26,2

Doughnuts (plain) 22 9Doughnuts (plain) 22,9

Onion rings 18,7

Chicken breast-breaded 18,1

Fish fillet-battered or 12,9breaded

,

Reviewed by Saguy & Dana, J. Food Engin. 56 (2003) 143-152Reviewed by Saguy & Dana, J. Food Engin. 56 (2003) 143 152

F.O.H. 11

Oil uptake by French‐fried potatoesO upta e by e c ed potatoes

Frying oil % Oil in potatoes Ref.

(Olive oil, vegetable shortening, sunflower oil)

5,7 – 12,8 Andrikopoulos et al., Int. J. Food Sci. Nutr. 53 

(2002) 351 363(2002) 351‐363

Soybean oil 6,0 – 14,0 Goburdhun & Jhurree Int. J. Food Sci Nutr 46 (1995)Food Sci. Nutr. 46 (1995) 

363‐371

Various 7,6 – 14,8 Reviewed by Saguy &Various 7,6  14,8 Reviewed by Saguy &Dana, J. Food Engin. 56 

(2003) 143‐152

Mean fried oil absorption ~10% in the French‐fries

Mean fried oil intake ~15g by consuming one batch (150g) of French‐fries

F.O.H. 12

TPM uptake by French‐fried potatoes

% TPM

Frying oil In the fried oil

In the oil absorbed

Ref.o abso bed

HOSO 5,516,0

4,915,4

Dobarganes et al.Eur. J. Lipid Sci. Technol.

102 (2000) 521 528102 (2000) 521-528Sunflower oil 7,019,1

6,418,7

Olive oil 21 0 20 0 Andrikopoulos et alOlive oilSunflower oil

21,026,0

20,029,0

Andrikopoulos et al.,Rev. Fr. Corps Grass 36

(1989) 127-129

It seems that %TPM in the fried oil reflects the %TPM in the absorbed oil

Preferential absorption of TPM‐fraction has also been reported  [Pokorny, Grasas y Aceites 49 (1998) 265‐270]Grasas y Aceites 49 (1998) 265‐270]

F.O.H. 13

How much does TPM loading count for?

By eating a batch (150 g) of French‐fries in oil within the limits ofreplenishment (20‐25% TPM) a quantity of approx. 3 g of TPM areconsumed

H ld h ibl d i bl h l h ff ( ) f 3 f TPM bHow could the possible undesirable health effect(s) of 3 g of TPM beneutralized?  

F.O.H. 14

SNO

Increase in TPM & PTG during successive frying 

Frying oils:8

101214

PM

SNOVSOVOO

ΤΡΜ

(1) Virgin olive oil (VOO)(2) Sunflower (SNO)(3) A mixture of vegetable oil (VSO)

02468

% T

P

Method: Deep fryerFood: PotatoesS f i 8

00 2 4 6 8 10

Διαδοχικά τηγανίσματαSuccessive fryings

Succesve fryings:  8

3.54.0

VSOSNOVOO

PTG

ΤPM : TOTAL POLAR MATERIALS 1.52.02.53.0

% P

TG

ΤPM : TOTAL POLAR MATERIALSPTG : ΗPLC (molecular exclusion)

0.00.51.0

0 2 4 6 8 10

F.O.H. 15

0 2 4 6 8 10Διαδοχικά τηγανίσματαSuccessive fryings

Increase in DDE during successive frying 

2,4‐decadienal (μg) per batch (150, (μg) p (g) french‐fries during 8 successivefryings , different oils

1: a mixture of seed oils2: palm oil3: oil4: cottonseed5: sunflower oil

F.O.H. 16G. Boskou, F.N. Salta, A. Chiou, E. Troullidou, and N.K. Andrikopoulos (2006).

Eur. J. Lipid Sci. Technol., 108, 109‐115

Based on TPM/PTG limits, how many times a frying oilcould be used successively?could be used successively?

I. Frying in household conditions:

None of the tested low linoleic vegetable oils exceeded the upper limitsof TPM (25‐27%) even after the 8th successive frying of potatoes (whichis the usual upper limit when using a domestic fryer)

I h f ll i d f d d iIn the following order of degradation: Virgin olive oil

Based on TPM/PTG limits, how many times a frying oilcould be used successively?could be used successively?

II. Frying in fast‐food and restaurants:

Country No of samples Samples (%) with TPM>25%

Ref.

Finland 20 60 Reviewed byFinland 20 60 Reviewed by Saguy & Dana,J. Food Engin.

56 (2003) 143‐152

France 31 48

Brazil 60 30 ( )Sweden 100 38

Germany 125 35

S i 1 4 34Spain 174 34

Greece 63 17 Andrikopoulos et al.,Food Serv. Technol.3 (2003) 49‐59

Saudi Arabia 55 15 Al KahfaniJAOCS

68 (1991) 857‐862

F.O.H. 18

Based on TPM/PTG limits, how many times a frying oilcould be used successively?could be used successively?

III Conclusions:

It seems that domestic frying is “quite safe” only when repeated

III.  Conclusions:

It seems that domestic frying is quite safe only when repeated  twice or thrice in the same oil, while at the 8th successive frying in the same oil, safety is rather questionable, according to TPM limits

It seems that the samples over the rejection limits comprise al l h h f h l d drelatively high part of the samples examined, indicating a

possible health risk for the consumers of fast‐foodsandrestaurants according to TPM and PTG limitsandrestaurants, according to TPM and PTG limits

F.O.H. 19

Trans-fatty acids in fats and oils obtained from restaurants

140A i

ntak

e

4045

mean

80100120140

e da

ilyTF

A

25303540

20406080

of G

reec

e

5101520

0

VO

O

SFO

CS

O

SFO

VS

O

Pal

m

MC

F

Per

cent

o

05

HU

VO

FRE

SH

UV

OO

KE

D

LUV

OFR

ES

H

UV

OO

KE

D

CF

FRE

SH

CF

OK

ED

Trans fatty acids (% w/w) in fresh and fried fats and lipids.

Coverage (%) of the average daily intake of trans fatty acids to Greece from a portion of 

H F HC

O L F LU

CO F

CO

lipids.HUVO = polyunsaturated, LUVO =monounsaturated, CF = cooking fats

french fries

F.O.H. 20 N Kalogeropoulos, NK Andrikopoulos, VA Tzamtzis (2002). Trans fatty acids in fats and oils used for domestic and commercialfryings in Greece. Proceedings 3rd Aegean Analytical Chemistry Days, Lesvos, 196‐199

Trans‐ fatty  acids(TFA)

Produced by isomerisation of double bonds of unsaturated fatty acids primarily in the hydrogenation of oils or refining vegetable oilsin the hydrogenation of oils or refining vegetable oils

They have been blamed for increasing the risk of many diseases (CHD, type 2 diabetes some cancers)diabetes, some cancers)

During frying they may produce small quantities at high temperatures (> 200o C) not normally applied in domestic fryingnot normally applied in domestic frying

In TFA intake from fried foods the content of trans in  fat or oil is very important

Intake of TFA: U.S. earlier 2.6‐12.8 g / day, recently 1.5‐2.2% of total energy. EU 2.8g/day, 0.5‐2% of energy intake, lower in Mediterranean countries

F.O.H.  21

Oxidized fatty acid derivatives

S di d f h fi iStudied for the first time:

2 isomers of epoxystearic (ES) acids

2 isomers of ketostearic (KS) acids

4 isomers of epoxyoleic (EO) acids

8 fryings of potatoes

in pan fryer

with 5 different oils

N Kalogeropoulos, FN Salta, A Chiou, NK Andrikopoulos (2007) Eur. J. Lipid Sci. Technol. 109, 1111‐1123

F.O.H.  21

Polar TG

O

O

O

O OHO

O

O

O

H

O

O O

OH

Schematic representation of the aforementioned activities on a TG molecule

F.O.H.23

Polymerized TG (dimers)

O

O OH O-O-

O O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

OO

O

O

O

O

O

O

O O

O

O

O

O

O

O

O O

O

O

O

O

O

24F.O.H.23α

PART TWO

POTENTIAL ROLE FOR HEALTH

F.O.H. 24

Experimental animalsDiet with frying oils (TPM)y g ( )

NO CARCINOGENESISNO CARCINOGENESISLOW TOXICITY

THE LOWER THE TPM PERCENTAGE IN OIL THE BETTER QUALITY

F.O.H. 25

How was the toxicity demonstrated ?How was the toxicity demonstrated ?

•Reduced growth•Hepatomegalyp g y•Renal dysfunction•Increased plasma cholesterol•Increased thyroxine•Reducing paraoxonase& increase in LDL oxidation

TPM in & increase in LDL oxidation

megadose

F.O.H. 26

Feeding exp. animals with frying fats and oils (I)

Exp. Animal

Feeding with frying fats

Period Target Affect RefAnimal frying fats

Albino wistar 

10% of the diet (SO)

3 w5 w

Glutathione (G)G peroxidase

Significant increase 1

male rats 7 w G reductase

Rats ‐ ‐ Mitochondrial respiratory chain

Hydroperoxide TBARSCoen yme Q

2

respiratory chain components

Coenzyme QCyt (b, c, c1. a1, a3) 

Rats 80g frying oil 8 w Liver microsomes TBARS 3Rats 80g frying oil per kg (SO, 

VOO)

8 w Liver microsomes TBARS  Hydroperoxides

Ubiquinone↓ (SO)Ubiquinone (VOO)

3

q ( )PUFA 

α‐TOC ↓(VOO)SFA not affected

F.O.H. 27

Feeding exp. animals with frying fats and oils (II)

Exp. Animal

Feeding with frying fats

Period Target Affect Ref

Guinea pigs

15% of the diet (Soybean oil)

12 w Liver microsomes

Growth rates ↓Feed efficiency ↓

TBARS  UPD l l

4

UPD‐glucuronyl‐transferase Cyt P‐450 

NADPH‐CytC‐reductase NADPH CytC reductase 

Wistar rats 10% of the diet (Coconut oil)

12 w Liver Lipids total ↓Cholesterol↓

5(Coconut oil)

Heart, serum

Cholesterol ↓Damage start

Lipids 

d

pCholesterol  DHA /EPA 

Kidney Damage start

F.O.H. 28

Feeding exp. animals with frying fats and oils (III)Exp. 

AnimalFeeding with frying fats

Period Target Affect Ref

Rats 5 ‐20 % heated and fried oils

20 w Activity of hepatic 

antioxidant

Catalase  GPX ↓GST↓

6

antioxidant enzymes

GST ↓SOD ↓

Rabbits 10% VOO1% Chol.

6 w Liver,brain, heart, aorta, platelets

Lipid peroxidation ↓Total / Oxidized glutathione 

GP

7

GP  GT 

G i i 15% ( b 60 d Li Li i ht 8Guinea pig 15% (soyabean oil)

60 d Liver Liver weight  Microsomal protein Cytochrome P450 

8

F.O.H. 29

Feeding exp. animals with frying fats and oils (IV)fExp. 

AnimalFeeding with frying fats

Period Target Affect Ref

Weaning  15% (soyabeans)  6 w Spleen 3H –thymidine incorporation  9long‐trans male rats

PGE2 α‐tocopherol ↓

Albino EtOH 45 d Plasma Aspartate transam (AST) 10Albino male rats

EtOHEtOH + FF (SO)

45 d Plasma Aspartate transam. (AST) Alkal. Phosphatase ( ALP)  

PL  ,Chol  ,TG 

10

Liver PL↓, Chol  ,TG  Phospholipases A, C 

Hepatocytes degradation (↓)

Rats 5 and 20%  20 w  Adipose  Absorption rate of fats (ct.) 11(peanut oil, 

sesame oil and coconut oil)

tissue  Excretion  Deposition 

F.O.H. 30

Feeding exp. animals with frying fats and oils (V)

Exp. Animal

Feeding with frying fats

Period Target Affect Ref

Rats 20g/100g 6 w Plasma Lipids↓, TG↓, Chol.↓ 12g/ g5g/100g 

(soyabean oil)  Liver tissue

p ↓, ↓, ↓

PPARα activatedGene expression 

Lipid metabolism alteredmRNA of acyl‐CoA 

Cyt P‐450  CYP4A protein CYP4A protein 

TG↓

Rats 0‐1 g/100gdi t ( li FA)

2 wLi

Peroxisomal acyl CoA oxidase  A l C A id

13

diet (cyclic FA) Liver Acyl‐ CoA oxidase  MUFA ↓γ‐linolenic 

Lipid metabolism affectedLipid metabolism affected

F.O.H. 31

Effect of frying fat fractions on exp. Animals (I)

Exp. Animal Feeding with frying fats

Period Target Affect Ref

1.Pups2.Weaningrats

Cyclic FA from linseed and SO heated (in vitro) 

‐ Liver sub‐cellular fractionsincubation

Mitochondrial & peroxisomal oxidation

14

Albino wistar rats

100 mg/kg t‐RP, t‐2N 

(α β unsaturated

24 h Urine Absorption & metabolism studies

15

(α,β unsaturated aldehydes)

Rabbits Isoenergetic diet (VOO, SO, HOSO)

8 w LDL‐Plasma(FA, CoQ, TBARS,

Peroxidation from SO > VOO

16

(VOO, SO, HOSO) (FA, CoQ, TBARS, α TOC)

VOO

F.O.H. 32

Effect of frying fat fractions on exp. Animals (II)Exp. Animal Feeding with Period Target Affect RefExp. Animal Feeding with 

frying fatsPeriod Target Affect

Rats 15% Shea oleine ( t f th t B

104 w Clinical th l

Body weight ↓F d i t k ↓

17

(nut of the tree B. parkii)

pathology & 

organs

Food intake ↓Cholesterol ↓

Alkal. phosphatase Heart weight Heart weight 

Incidence of pulmonary lipidosis 

Rats 8% olive oil (48 & 69 potato frying operations)

8 d Liver, spleen, skin.

Faecal iron (ct)Urinary iron excretion 

Serum iron (ct)

18

8% SO (48 potato frying operations

Iron content in liver & skin (ct)

Wistar Rats 1 Sardines fried 1): 3 w Serum Chol ↓ 19Wistar Rats 1.Sardines fried    in VOO

2. Fat from    sardines

1): 3 wchol. loading.2):2 w chol. free

Serum

Liver

Chol. ↓

Lipids ↓

19

p ↓

F.O.H. 33

Effect of exp. frying fat consumption in humans (I)

Subject Consumption Period Target Affect Ref.

Human (men) (8) 

TG with labelled linoleic & linolenic cis 

48 h CO2 excretion in breath

Equal energy contribution from cis & trans

Oxidation of linolenic > 

20

& trans linoleic

Human (men) (16)

Native & heated 

4 h Dilute serumIsolated LDL

Susceptibility of oxidation of serum lipoproteins by Cu2+ 

21( ) ( )

safflower & olive oils

p p yin the postprandial period following meals rich in 

polyunsaturated vegetable oils (heated & native) and 

heated olive oil 

F.O.H. 34

Effect of exp. frying fat consumption in humans (II)

Subject Consumption Period Target Affect Ref.

31 male, type II diabetic patients22 poor glycemic

Corn oil 2.5 h Serum chylomicron

Conjugated dienes Oxidized lipids (ct.)

22

22 poor glycemic control, 

9 good glycemic control

Men (10) 64.4 g fat  that had been used for deep frying 

4 h Plasma Atherogenesis accelerated

23

F.O.H. 35

Human exposure to fumes from frying fats Subject Exposure Target Affect Ref.

Women Cooking oil fumes  Lung  DNA adduct formation 24from frying fish (CL‐3 cells)

Chinese women

Carcinogenic chemicals emitted 

Lung PAH concentration in fumes  25

from not cooking oil

Women (459)

Cooking fumes from rapeseed & linseed

Lung Risk of lung cancer 26(459) rapeseed & linseed 

oils

Non Coal dust frequent Lung Risk of lung adenocarcinoma 27Non‐smoking females

Coal dust, frequent frying and deep frying 

food

Lung Risk of lung adenocarcinoma 27

Chinese Cooking oil fumes: Lung Cancer 28Chinese women (94 prof cooks, 43 house 

Cooking oil fumes:Benzo (a) pyrene, 1,3 butadiene (soyabean 

oil)

Lung Cancer

ho GG1 mRNA expression frequency 

28

wives)) q y

F.O.H. 36

BIBLIOGRAPHY on PART TWO “Potential Role for Health”

1. Saka et.al. Biochimie 84 (2002) 661‐665.

on PART TWO  Potential Role for Health  

15. Grootveld et.al. J. Clin. Invest. 101 (1998) 1210‐1218.1. Saka et.al. Biochimie 84 (2002) 661 665.

2. Lopez – Frias & Mataix. J. Bioenerg. Biomembr. 34 (2002) 127‐134.

3. Quiles et.al. Br. J. Nutr. 88 (2002) 57‐65.

4. Liu & Chan. J. Nutr. Sci. Vitaminol. 46 (2000) 240‐245.

16. Ochoa et.al. Nutrition 18 (2002) 60‐65.

17. Carthew et.al. Food Chem. Toxicol. 39 (2001) 801‐815.

18. Renez‐Granados et.al. J. Sci. Food Agric. 81 (2002) 115‐120.

5. Ammu et.al. Nahrung 44 (2000) 368‐372.

6. Narasimhamurthy & Raina. Indian J. Exp. Biol. 37 (1999) 1042‐1045.

7. De la Cruz et.al. Biochim. Biophys. Acta 1485 (2000) 36‐44.

l l ( )

19. Sanchez‐Muniz J. Nutr. 133 (2003) 2302‐2308.

20. Bretillon et.al. J. Lipid Res. 42 (2001) 995‐997.

21. Sutherland et.al. Atherosclerosis 160 (2002) 195‐203.

22 Starpans et al Diabetes Care 22 (1999) 300 3068. Liu et.al. J. Nutr. Sci. Vitaminol. 46 (2000) 137‐140.

9. Bi‐Fong Lin. Nutrition Res. 17 (1997) 729‐740.

10. Aruma et.al. Hepatology Res. 24 (2002) 125‐137.

11 Narasimhamurthy & Raina Eur Food Res Technol 210 (2000) 402

22. Starpans et.al. Diabetes Care 22 (1999) 300‐306.

23. Williams et.al. J. Am. Col. Cardiol. 33 (1999) 1050‐1055.

24. Sen‐Chin Yang et.al. Chem. Res. Toxicol. 13 (2000) 1046‐1050.

11. Narasimhamurthy & Raina. Eur. Food Res. Technol. 210 (2000) 402.

12. Pei‐Min Chao et.al. J. Nutr. 131 (2001) 3166‐3174.

13. Martin et.al. J. Nutr. 130 (2000) 1524‐1530.

14. Joffre et.al. J. Nutr. Biochem. 12 (2001) 554‐558.

25. Siegmann & Sattler. J. Aerosol. Sci. 27S (1996) 493‐494.

26. Metayer et.al. Lung Cancer 35 (2002) 111‐117.

27. Xu‐Dong Dai et.al. Lung Cancer 1 (1996) S 85‐91.

28 Ch l J T i l E i H l h 65 (2002) 265 27828. Cherng et.al. J. Toxicol. Environ. Health 65 (2002) 265‐278.

F.O.H. 37

Aromatic and heterocyclic amines in public health

I. The formation of HCAs during cooking can be decreased by:

1. natural and synthetic antioxidants

2. thrypthophan or proline

3. by removing the essential creatine through brief microwave cooking priory g g g pto frying or boiling

4. the amounts of HCAs in cooked foods are small, but other components in4. the amounts of HCAs in cooked foods are small, but other components indiet such as ω‐6 polyunsaturated oils have powerful promoting effects intarget organs of HCAs

F.O.H. 38

Aromatic and heterocyclic amines in public health

II. Prevention of the formation of heterocyclic amines

P % D f f ti fProcess % Decrease of formation ofmutagens during frying

Mixing 7 15% weight of soy protein concentrate with 90Mixing 7‐15% weight of soy protein concentrate withground beef

90

Mixing 2,5 g pectin or textured procomm of 4.0 bontac(soy proteins products) to 50g beef patties

50‐60(soy proteins products) to 50g beef patties

Mixing 1.3 mM chlorogenic acid or 10‐20 mM BHA to 50g beef patties

50‐60

Applying 0, 0.5, 2.5, or 7% solution in water of acommercial green tea polyphenol to the two surfacesof 30g beef patties

Lowering

Using 159 175 521 589mg of a black tea polyphenols 70 70 90 95Using 159, 175, 521, 589mg of a black tea polyphenolsto the both sides of 30g beef patties

70, 70, 90, 95

Applying L‐tryptophane or L‐proline to the surface of Loweringground meat

Weisburger . Mutation Research 506‐507, (2002), 9‐20F.O.H. 39

Acrylamide – hot off the frying pan

“There is currently no link between acrylamide levels in food and cancer risk”between acrylamide levels in food and cancer risk

Dr. Colette Kelly, British Nutrition Foundation, Nutrition Bulletin 28 (2003) 5-6.

F.O.H. 40

PART THREEPART THREE

NUTRITIONAL EFFECT OF FRYING

F.O.H. 41

Nutritional effect of frying (I)I. Vitamins

Vitamin Cooked food Cooking method % Retention

Vitamin A Vegetables BoilingFrying

8676

Vitamin C Potatoes Baking 80 – 85Vitamin C Potatoes

Potatoes

BakingBoilingFryingVarious 

80  8560 – 8025 – 8057 – 96

Vegetables Meat, poultry

VariousFryingStewingO

57 – 77808080Oven 80

Vitamin E (from frying oil)

Potatoes (fast food)

Deep‐frying

f

67

Potatoes (home made)

Deep‐frying(3‐5 Frying cycles)

Pan‐frying(2 3 Frying cycles)

50

~50(2‐3 Frying cycles)

F.O.H. 42

II Fatt acids and micro constit ents

Nutritional effect of frying (II)II. Fatty acids and micro-constituents

Constituents Cooked food Cooking method Comments

Total trans‐FA Potatoes (in VOO, HOSO, SO)Potatoes (in VOO, SO, VS)

8 Frying cycles20 Frying cycles8 Frying cycles

20.8 – 45.2 mg/140g86.4 – 129 mg/140gNegligible difference 

f f h ilMUFAPUFA

‐//‐‐//‐

‐//‐‐//‐

from fresh oils‐//‐‐//‐

Minerals PotatoesFish

Frying BoilingBaking

Minuscule decrease. Negligible losses.

Polyphenols Potatoes (in VOO) Deep‐fryingPan‐frying

(4‐5 Frying cycles)

Ref. 50%Ref. 50%

Squalene (1) Potatoes (in VOO)(2) Small fishes

(in VOO)

(1) Deep fryingPan frying (1‐8 cycles)(2) Pan frying (1 cycle)

10‐20% of the dailysqualene intake

Phytosterols French Fries (in various frying oils)

Pan frying (1 ‐3 cycles) 7‐37% of the daily intake

Nutritional effect of frying (III)

III. Conclusions

High retention of Vitamin A and C (“approx. mean” 70%) in various foodsEnrichment of foods with Vitamin E from the absorbed oil (over 50% ofRDA)RDA)Enrichment of foods with the absorbed oil increases the caloric intake, which is important for the developing countries

h f f d h l l h l & h l f hEnrichment of foods with squalene, polyphenols  & phytosterols from theabsorbed oil (VOO)Low formation of total trans‐FA (up to 5 mg/g oil) during frying. That( p g/g ) g y gcorresponds to loading a batch of potatoes (150 g) with 75 mgwhich is much lower to the typical Western consumption (up to 4000 mg)

Andrikopoulos et al. Int. J. Food Sci. Technol. 37 (2002) 177‐190A d ik l t l I t J F d S i N t 53 (2002) 351 363

F.O.H. 44

Ruiz‐Roso. Grasas y Aceites. 49 (1998) 347‐351Eheart & Gott Food Technol 19 (1965) 181 188Andrikopoulos et al. Int. J. Food Sci. Nutr. 53 (2002) 351‐363

Saguy & Dana. J. Food Engin. 56 (2003) 143‐152Fillion & Henry.  Int. J. Food Sci. Nutr. 49 (1998) 157‐168Romero et al. J. Agr. Food Chem. 47 (1999) 1168‐1173

Eheart & Gott. Food Technol. 19 (1965) 181‐188Gomez‐Alonso et al. J. Agr. Food Chem. 47 (2003) 667‐672Kalogeropoulos & Andrikopoulos, Int. J. Food Sci. Nutr. 55 (2003) 125‐9Kalogeropoulos et al. J. Food Sci. Agric. 84 (2004) 1750‐8

Maintenance of antioxidants Beneficial  ingredients in f i d f d

a‐τοκοφερόληfried foods

l h lpolyphenolsAfter  the eighth frying the 15‐30% tocopherols and polyphenols are maintained in oil “protection” of TGs

F.O.H. 45

in oil; “protection” of TGs

NK Andrikopoulos, GVZ Dedousis, A Falirea, N Kalogeropoulos, H Hatzinicola (2002). Intern. J. Food Sci. Nutr., 53, 351‐363

Beneficial  ingredients in fried foods

Intake of phytosterolsp yfrom eating 1 portion (200g) potatoes fried in oil that have been fried 1‐3 times: covers 7‐37% of typical daily intake (250mg)( g)

Potatoes frying in vegetable oils resulted in the enrichment with phytosterolsF i d id ti f h t t lFrying caused oxidation of phytosterols(α) ↑ with frying time, (β) ↑ in more unsaturated oils( ) f

F.O.H. 46

(γ) pan> fryer

Questions arising

A th li it f TPM/PTG t ti f bli h lth?

Questions arising

Are the limits of TPM/PTG protective for public health?

Is the defense system of the body adequate to neutralize the d i bl ff t f TPM f b t h f F h f i ?undesirable effect of TPM from a batch of French-fries?

How much rich-antioxidant foods should be consumed together ith f i d f d d l ti diti i d twith fried foods under real consumption conditions in order to

neutralize the undesirable effects?

Wh t i th bi il bilit f th ti id t d?What is the bioavailability of the antioxidants consumed?

Is the capacity of the detoxification system of the body “good h” t th f i b d t d th d il lenough” to overcome the frying by-products under the daily real

consumption of fried foods?

F.O.H. 47

Harmful ingredients

TPM (1 batch of French Fries)CuSO4 (5μΜ) ( )CuSO4 (5μΜ)

plus LDL

60

80

60

80

ion

ion

20

40

20

40

%  oxidati

%  oxidati

F.O.H. 48

00

time (h) time (h)

2

TPM induced LDL oxidation (in vitro)

22

2

11

2

1. LDL + TPM from fried oils in domestic use8 – 13%

2. LDL + TPM from fried oils in fast foods & restaurants

F.O.H. 49

TPM induced LDL oxidation (in vitro)

5 μM CuSO4 induced LDL oxidation is defined as 100%oxidationoxidation

TPM correspond to the quantity that it is distributed to blood LDL when eating a batch (150 g) of potatoesFrench‐fried in oils of different deterioration (as indicated)

NPM (Non Polar Materials) exhibit no oxidative effect on LDL 

Oleuropein = one of the main antioxidant polyphenols inolive oil

10μM Oleuropein in the test cuvette corresponds to 5 8 li i d f l f l d li ilapprox. 5‐8 olive pieces and a spoonful of salad olive oil

F.O.H. 50

MPM (DDE) induced LDL oxidation (in vitro)

2

2

11

vit E20μΜ

1. LDL + MPM from fried oils in domestic use

2 LDL + MPM from fried oils in fast foods & restaurants2. LDL + MPM from fried oils in fast foods & restaurants

F.O.H. 51

MPM (DDE) induced LDL oxidation (in vitro)

MPM = Medium Polarity Materials isolated from fried oilsy(mainly 2,4‐trans‐trans‐decadienal)

MPM contained in a batch of potatoes French fried inMPM contained in a batch of potatoes French‐fried inoil with 14% TPM exhibits approx. 100% LDL oxidation(same to that of  5 μM CuSO4)

Vitamin E contained in 30 ml of salad oil (approx. 750 ppmVit E) results in 50% inhibition of human body LDL oxidationVit. E) results in 50% inhibition of human body LDL oxidation

F.O.H. 52

Oleuropein vs PAFOleuropein vs PAF

80

100

uced

60

80

PAF

indu

gatio

n

20

40

hibi

tion

in

aggr

e g

IC 0 41 M

0

20

% In

h IC50: 0,41mM

0 0,25 0,5 0,75 1 1,25Oleuropein (mM)

Andrikopoulos, Antonopoulou, Kaliora, Leb-Wiss Tech, 35, 479-484 (2002)F.O.H. 53

Oil Frying process1 batch of frenc‐fries (150g)

Oil  (15g)25% ΤΡΑ (~3g)

In vitro οξείδωση LDL

proportional to the t t i th hConsumption 5‐10 content in the human 

body

Consumption 5‐10 olives and vegetable salad with olive oil (20g)with olive oil (20g)

F.O.H. 54

Virgin olive oilVirgin olive oil (VOO) in frying(VOO) in frying

F.O.H. 55

Squalene in French‐fries 

Squalene in home frying with extra virgin olive oil• fryer: 409±6.4 mg/100 g y g/ g• pan:   387±5.7 mg/100 g• after 8 fryings maintaining 80‐90% original squalene

F.O.H. 56N. Kalogeropoulos and N.K. Andrikopoulos (2004). Squalene in oils and fats from domestic and commercial fryings of 

potatoes.  Intern. J. Food Sci. Nutr., 55, 125‐129

Conclusively Conclusively ……yy1. Frying up to 8 times using the same seed results in TPM 

25%

Bioavailability of ΟΗ‐tyrosol & metabolites in plasma

3145 (3145 (±±341)341)ng/mLng/mL 2263 (2263 (±±170)170)

ng/mLng/mLng/mLng/mL

122 (122 (±±13)13) 14742 (14742 (±±941)941)( )ng/mLng/mL

14742 (14742 (±±941)941)ng/mLng/mL

A.M. Kountouri, A. Mylona, A.C. Kaliora, N.K. Andrikopoulos, Phytomedicine 14 (2007) 659–667

F.O.H. 58

Olive leaf extract & frying

Frying potatoes in pan ‐ oils i h d i h li l f

Ελαιόλαδο

12

14

16

αιο

OLE πριν OLE μετά Σύνολο πριν

enriched with olive leaf extract:Polyphenols in the oil before and after frying

6

8

10

12

Διατήρηση

στο

έλα

τηγανίσμ

ατος

Σύνολο μετά

after frying 

0

2

4

0 120 240εμπλουτισμός (mg/kg)

% Δ

εμπλουτισμός (mg/kg)

Ηλιέλαιο

16

18

20OLE πριν OLE μετά

Φοινικέλαιο9

10OLE πριν OLE μετά

8

10

12

14

16

τήρη

ση στο

έλαιο

ηγανίσμα

τος

Σύνολο πρινΣύνολο μετά

4

5

6

7

8

ήρησ

η στο έλαιο

γανίσμ

ατος

OLE μετά Σύνολο πρινΣύνολο μετά

0

2

4

6

0 120 240

% Διατ τη

0

1

2

3

4

% Διατή τηγ

F.O.H. 59

Chiou, Salta, Kalogeropoulos, Mylona, Ntalla, Andrikopoulos, Journal of Food Science 2007,72,574-584

0 120 240εμπλουτισμός (mg/kg)

0 120 240εμπλουτισμός (mg/kg)

Polyphenols & cancer yp

Polyphenols extracted from olive fruits induce ypstomach cancer cell death 

F.O.H. 60

Kountouri AM, Kaliora AC, Koumbi L, Andrikopoulos NK  Eur J Cancer Prev. 2009 Feb;18(1):33‐9. 

Polyphenols & cancer yp

1‐7, different polyphenol p ypstandards 

Standard olive oil polyphenols induce apoptosis of leukemicStandard olive oil polyphenols induce  apoptosis  of leukemic cells my natural killers

F.O.H.  61

Dedoussis GV, Kaliora AC, Andrikopoulos NK. Cell Biol Int. 2005 Nov;29(11):884‐9. 

General commentsThe in vitro experiments on LDL oxidation gave evidence thatTPM/ PTG limits could be considered as “quite safe” for humansfor moderate consumption of fried foodsfor moderate consumption of fried foods.

Nevertheless the possibility of consumption of TPM overloadedfried foods in fast food and restaurants are relatively high. Thus, more concern by the authorities should be taken.

Consumption of foods rich in antioxidants together with friedfoods has, in vitro, a remarkable protective effect from TPM undesirable properties. p p

The detoxification system(s) is “moved on” indicating that someoxidation and toxic effects occur in the body after the consumptionoxidation and toxic effects occur in the body after the consumptionof fried food and their fractions.

• The most toxic might be the cyclic FA by-products and the frying-fumesThe most toxic might be the cyclic FA by products and the frying fumes

F.O.H. 61

Thank you for your attention