Transcript Dias nummer 1

Fordele og ulemper ved madlavning
Eva Lydeking-Olsen
FUB
Oslo 2013
.
Foredraget vil belyse hvad der er af fordele og ulemper ved forskellige måder at
tilberede eller ikke-tilberede maden på. Vi vil gennemhulle en del af raw-foodmyterne/ læresætningerne og se på hvad der sker når maden opvarmes på
forskellig vis og hvordan den påvirker os ift dannelse af toxiner som Acrylamid,
Advanced Glycation Endproducts, oxidation af kolesterol mm ift specifikke
fødegrupper og specifikker opvarmningsmetoder, herunder et kritisk blik på
mikrobølgeovne.
Microwave heating and human health effects –
summary
Neutral effects Beneficial
effects
•Vitamin loss
•Protein
denaturation
•Cis-trans
isomeration in
PUFA
•Thermic
mutagens
•N-3 EFA
•Antigenic
stability
•Mineral balance
•Oxidative
damage :
peroxides &
anisidine
•Antinutrients
destroyed:
Trypsin
inhibitors
Hemagglutinin
activity
Tannins
Saponins
•Glucosinolates
increase in
broccoli
•Aflatoxin
decrease
•Mutagenic
products
decrease
Potential problematic effects
Not for human
study
Lead leaking from
utensils
•Amino acid
isomerisation
(Lubec 1989)
•Acrylamide –
reproduction
•Extraction of toxic
/ damaging
substances:
Pesticides
Mycotoxins
Heavy Metals
Feasible for a human study
•Oxidized cholesterol
•Flavonoids, broccoli
•Isothiocyanates, broccoli
•Repeat Blanc & Hertel,
1992, add reticulocytes
•Oxidative stress:
catalase, SOD, NO,
glutathione reductaseand peroxidase
Glutathione transferase
Thioredoxin reductase
Inflammatory / Acute
Phase proteins
Fordele ved at varme maden op
Fordøjelighed& energitæthed
Mindske
ANTInutrienter
Fytin
Trypsinhæmmere
Hæmagglutininer
/ Lektiner
Saponiner
Tanniner
Denaturering proteiner
Stivelse-forklistring
Biotilgængelighed carotenoider oma
Opvarmning
Hygiejne
*DESTRUKTION AF
Virus
Bakterier
Parasitter
Energimæssige
faktorer
& balancer
Yin/Yang
Syre/base
Enzymer
Livskraft
Næringsstoffer ved opvarmning
Typical Maximum Nutrient Losses (as compared to raw food)
Vitamins
Freeze
Dry
Cook
5%
50%
25%
35%
10%
Alpha & beta Carotene
5%
50%
25%
35%
10%
Beta Cryptoxanthin
5%
50%
25%
35%
10%
Lycopen,Lutein+Zeaxanthin
5%
50%
25%
35%
10%
Vitamin C
30%
80%
50%
75%
50%
Thiamin
5%
30%
55%
70%
40%
Riboflavin
0%
10%
25%
45%
5%
Niacin
0%
10%
40%
55%
5%
Vitamin B6, pyridoxin
0%
10%
50%
65%
45%
Folat, fødevarer & tilsat folinsyre
5%
50%
70%
75%
30%
Vitamin B12
0%
0%
45%
50%
45%
Vitamin A, retinol; RAE
Cook+Drain Reheat
USDA Table of Nutrient Retention Factors (2003)
Næringsstoffer ved opvarmning
Typical Maximum Nutrient Losses (as compared to raw food)
Minerals
Freeze
Dry
Cook Cook+Drain Reheat
Calcium
Iron
Magnesium
5%
0%
0%
0%
20%
35%
25%
40%
0%
0%
0%
0%
25%
40%
0%
Phosphorus
0%
0%
25%
35%
0%
Potassium
10%
0%
30%
70%
0%
Sodium
Zinc
Copper
0%
0%
10%
0%
0%
0%
25%
25%
40%
55%
25%
45%
0%
0%
0%
USDA Table of Nutrient Retention Factors (2003)
Danmark: Dr. Kristine
Nolfi; helbredte sin
brystkræft ved hjælp
af råkost
1941: Humlegården.
Alma Nissen;
helbredte sig selv for
gigt ved hjælp af
hvidløg, kartoffelvand
og rå kost Brendal
Helsehjem i Sverige.
* Raw vegetarer (+æg og mejeriprodukter)
* Raw veganer (minus animalsk)
* Raw omnivorer (alt brugbart fra plante- og
dyreriget)
* Raw carnivorer ( kun fra dyreriget )
Raw Food
USA : Ann Wigmore;
helbredte sig selv for
kræft ved hjælp af
”levende kost”
1968 Hippocrates
Health Institute.
ALTID MINDST 75 % rå mad.
•Gourmet-Raw Food og består af ret meget
fedt fra olier, nødder og kerner.
• ”80-10-10” hvor 80% =kulhydrater fra frugt
og grønt, 10% =fedt fra nødder/kerner og
10% =protein ligeledes fra frugt og grønt.
•Solskinsmad er rå, uforarbejdede planter og
frugter, nødder og kerner + kogte korn og
ingen restriktioner om at maden skal være rå
men det anbefales.
Kogning af gulerod det øger indholdet af
målbare carotenoider, der fungerer som
antioxidanter.
Raw Food
Den kemiske
struktur i kosten
ændres ved
opvarmning og
nedsætter den
næringsmæssige
værdi og gør maden
toxisk og uden liv –
og tilfører derfor
heller ikke liv til
vores krop og celler.
•Kogning kan nedbryde fødevarens
cellevægge, så de sunde næringsstoffer
frigives.
• *Kogt tomat har for eksempel et langt
højere indhold af lycopen, end friske
tomater.
*Broccoli der var stegt i ekstra jomfruolivenolie eller solsikkeolie havde samme
c-vitaminindhold, som i den rå broccoli.
Raw Food
indeholder det
højest mulige
indhold af alle de
nødvendige
næringsstoffer …
Raw Food
Med Raw Food får
du nemt dækket alle
dine næringsbehov i
form af vitaminer,
mineraler, enzymer,
fibre, antioxidanter,
fedtsyrer, fibre,
vand og oxygen.
Vitaminer og mineraler Daglig anbefaling
for ”kvinder 31-60 år” NNA 2004
Dagligt indtag i 2 ugers Raw Food Diæt.
(gn.snit pr dag)
Vitamin A i RE
700
1533,6
Vitamin D i mcg 7,5
0
Vitamin E i TE
8
39,4
Vitamin C i mg
75
445,5
Vitamin B1 i mg 1,1
1,8
Vitamin B2 i mg
1,3
1,5
Vitamin B3 i NE
15
21,3
Vitamin B6/mg
1,2
2,2
Folat i mcg
300
847,3
Vitamin B12 i mcg 2,0
0
Raw Food
indeholder det
højest mulige
indhold af alle de
nødvendige
næringsstoffer …
Raw Food
Med Raw Food får
du nemt dækket alle
dine næringsbehov i
form af vitaminer,
mineraler, enzymer,
fibre, antioxidanter,
fedtsyrer, fibre,
vand og oxygen.
Vitaminer og mineraler Daglig anbefaling
for ”kvinder 31-60 år” NNA 2004
Dagligt indtag i 2 ugers Raw Food Diæt.
(gn.snit pr dag)
Calcium i mg
800
620,8
Fosfor i mg
600
1107,4
Magnesium i mg
280
352,4
Kalium i mg
3100
4621,3
Jern i mg
15,9
15,3
Zink i mg
7
7,1
Kobber i mg
0,9
2,6
Selen i mcg
40
34,9
Jod i mcg
150
22,4
Chrom i mcg Ikke NNA
39,7
Mangan i mg Ikke NNA
4,7
Raw Food’er behøver tilskud af især Dvitamin, B12 og Kalcium
God multivitamin med min 140 mcg. jod og
40 mcg. Selen = dækket ind på minimum.
Jo mere vi tærer på eget lager, jo
hurtigere ældes vi.
Manglende enzymer kan betyde, at
vi ophober affaldsstoffer og
ufordøjede madrester der kan føre
til træthed, forstoppelse,
vægtøgning, inflammation og
livsstilssygdomme på lang sigt.
Faktisk kan du ved at spise mad med
et højt indhold af enzymer, forøge
mængden af kroppens egne
naturlige enzymer
– overskydende enzymer fra kosten
bliver optaget i kroppes
enzymdepoter, hvorfor de kan blive
sendt rundt i kroppen, og indgå i
tusindvis af livsvigtige processer.
Raw Food
Opvarmning ødelægger enzymer =
kroppen tærer på sit eget
enzymlager.
NEJ.
Raw Food
Behovet for protein er forskellig fra person til
person.
NNA (2004) anbefaler 10-20%
(helst 15% der svarer til ca. 0,75 g/kg kropsvægt)
- til almindelige raske personer.
En Raw Food diæt opfylder slet ikke dette
anbefalede behov.
Kun 5 dage ud af de 14 beregnede dage,
sniger %-andelen sig op over de 10%
= 4-5% fra det anbefalede daglige behov.
På en enkelt dag er proteinindtaget helt nede på 5%.
Raw Food
Dag:
Indtag pr
dag, kcal:
Overskud/
underskud/dag
Person 1
Overskud/
underskud/dag
Person 2.
Mandag
Tirsdag
Onsdag
Torsdag
Fredag
Lørdag
Søndag
2447
3127
1930
1483
1894
2338
1467
+462
+1142
-55
-502
-91
+353
-517
+490
+1170
-27
-474
-63
+381
-490
Mandag
Tirsdag
Onsdag
Torsdag
Fredag
Lørdag
Søndag
1695
2223
2063
3185
1621
3302
1811
-290
+238
+78
+1200
-364
+1317
-174
-262
+266
+106
+1228
-336
+1345
-146
+2797
+3188
Samlet
Raw Food
Energi %
fordeling
Raw food gns. 14 dage
NNA 2004
Protein
9.2
10-15
Fedt
60.5
25-35
Kulhydrat
30.3
55
ALT for højt fedt –indtag:
Proinflammatorisk, mætheden ikke god nok
ALT for lavt protein-indtag:
Manglende mæthed,
manglede byggesten til signalstoffer,
vævsopbygning og
nervesystem, nedadgående forbrænding
Grøntsagers oxidative robusthed ift.
opvarmning
Markers of oxidative stress
Am J Clin Nutr 2004;79:1060 –72
Several methods for measuring antioxidant activity
Method
Food Sample Human samples
Oxygen Radical Absorbance Capacity (ORAC)
x
-
ABTS = 2,2'-azino-bis(3-ethylbenzothiazoline-6sulphonic acid)
x
x
TEAC Trolox Equivalent Antioxidant Capacity (often
ABTS method)
x
x
FRAP Ferric Reducing Capacity of Plasma (Trolox
standard)
-
x
MDA-TBAR Peroxidation of phospholipid liposomes x
/ Malondialdehyde-thiobarbituric adduct
x
Isoprostanes (oxidation of Arachidonic Acid)
-
x
Plasma Cerbonyls (protein oxidation)
-
x
AGE, Advanced Glycation Endproducts (glycotoxin
in protein-fat rich foods)
x
x
Markers of oxidative stress
Biomarkers of
plasma lipid
and protein
oxidation
Antioxidant
capacity
markers
Defense
Enzyme
Activities
Plasma lipoprotein lag time
FRAP assay
(ferric reducing ability of
plasma)
Erytrocyte glutathione
reductase (GST)
Plasma lysine carbonyls
Total plasma MDA
(malon-di-aldehyde)
LDL-MDA
TEAC assay
(spectrophotometric
determination of
antioxidant capacity)
Isoprostanes in urine
Oxygen consumption
Glutathione peroxidase
(Gpx)
Catalase
Superoxide dismutase
Markers of oxidative stress
J. Nutr. 133:2812-2819, September 2003
FRAP
(mmol Fe2+/kg FW3)
TRAP
(mmol Trolox/kg FW)
TEAC
(mmol Trolox/kg FW)
Fruit
Value
Rank
Value
Rank
Value
Rank
Apple (red
Delicious)
3.84
24
2.23
20
1.59
22
Apple
(yellow
Golden)
3.23
26
1.54
24
1.31
25
Apricot
4.02
23
2.29
19
1.44
24
Banana
2.28
28
1.05
27
0.64
30
Blackberry
51.53
1
21.01
1
20.24
1
Blueberry
18.61
9
9.30
7
7.43
10
Cherry
8.10
16
4.17
12
2.69
16
Clementin
e
8.88
15
2.74
16
3.10
14
Fig
5.82
20
2.06
21
2.47
18
Markers of oxidative stress
…TEAC assay is done both in foods and biological fluids
J. Nutr. 133:2812-2819, September 2003
FRAP
(mmol Fe2+/kg FW3)
TRAP
(mmol Trolox/kg FW)
TEAC
(mmol Trolox/kg FW)
Vegetable
Value
Rank
Value
Rank
Value
Rank
Artichoke
11.09
12
6.85
3
1.55
20
Arugula
14.30
7
4.22
10
3.55
9
Asparagus
10.60
13
9.71
1
3.92
7
Avocado
4.90
21
1.87
21
2.22
15
Beet
13.13
8
2.70
16
5.21
5
Beetroot
(red cooked)
15.31
6
7.67
2
2.94
13
Broccoli
11.67
9
3.07
12
3.04
12
Cabbage
(green)
5.79
17
2.83
14
1.15
24
Cabbage
(Savoy)
8.17
14
2.35
18
2.08
16
Study
Isothiocyanates, broccoli. Cancer preventive, detoxifying.
Flavonoids, broccoli. Important phytonutrients with
antioxidant and detoxifying effects, minimizing genetic
damage in cells.
Organic broccoli (var. Marathon) was heated by 4-6 methods under standardized
conditions and samples taken for analysis.
•
Microwave 1000 Watt (full effect)
•
Boiling covered with water, variable time for broccoli (minutes)
•
Induction heating, with and without water
•
Steaming without water contact, – both electrical and induction (minutes)
Isothiocyanates in broccoli
Sulphur – containing phytonutrients = glucosinolates
Converted to isothiocyanates, ITCs, by the myrosinase enzyme
Active compound isothiocyanate is measured in food or urine
Proces
Broccoli with glucosinolates and residual enzyme activity +
Cutting in to smaller pieces or chewing =
•Protection from DNA damage
•Inhibit cancer formation
•Detoxify environmental pollutants
•Convert estrogen to less biologiacally forms (16 OH to 2 OH)
•Inhibit several cancer forms
After cutting the broccoli, short term heating (30- 60 sec) is considered the
best way to prepare the broccoli for optimum health benefit.
(Smith 2003).
Isothiocyanates in broccoli
Samples
• Organic broccoli, var. Marathon
• Grown i Italy
• One batch from the ecological retailer Solhjulet
• Aliquots of 200 g of flower and small stems
No flavonoids and little isothiocyanates in the stalk and, and heated
according to table.
- Sample were divided in two portions of 100 g
- One for flavonoid analysis
- One for analysis of isothiocyanates.
- Samples for analysis of flavonoids were frozen at -20 ºC (Pia Knuthsen),
isothiocyanates prepared and analyzed immediately (Mette Kristensen).
Result : Isothiocyanates in broccoli
Best culinary quality is
considered crisp (al-dente)
with a clear green color,
obtained at 1-2 minutes
heating
3500
nmol ITC/g
broccoli
3000
2500
2000
•All heating with water
contact, MW at low
effect/longer time and
steaming 4 and 10 min
destroy enzyme activity.
1500
1000
500
0
1 min 2 min
4 min 10
min
Mikrobølge, 900W
Induktion kogning
Alm. kogning
Induktion dampning
Alm. dampning
Rå, ubehandlet
* Short –term heating, 1 and
2 minutes is culinary good,
results are summarized in
figure.
Flavonoids
Some of the most important phytonutrients
•antioxidant
•other physiologically important regulatory effects
•minimizing genetic damage and cancer development ( laboratory)
•improving the liver capacity of detoxifying environmental pollutants and
carcinogenic hormones.
Earlier studies
1. Ioku found better retaining of flavonoids in MW without water, similar to oil-frying
whereas boiling in water leaked the flavonoids ~ 30 % to the water
If the cooking-water is used there is no health effects (Ioku 2001).
2.Vallejo found that broccoli boiling in water and pressure cooking created a loss of
flavonoids of 66% and 47%, respectively. MW with added water almost completely
destroyed the flavonoids with a 97 % loss, whereas steaming retained the flavonoids
completely (Vallejo 2003).
3.Apigenin from parsley has been shown to be microwave stable (Nielsen 1999).
Result:Flavonoids in broccoli
Figure 4. Change in flavonoids i broccoli, raw and after different
heating methods.
Aglycones, mg/100g, corrected for fluid loss/uptake
12,0
mg/100g
10,0
8,0
6,0
4,0
2,0
0,0
raw
steaming, 1 steaming, 2 mikro, 900 mikro, 900
min
min
W, 1 min
W, 2 min
Quercetin
Kaempferol
mikro, 500 mikro, 150
W, 8 min W, 24 min
Result: Flavonoids in broccoli
%
Figure 5. Percent change in flavonoids in broccoli after different
heating methods and compared to raw.
Aglycones, mg/ 100g and corrected for fluid loss/uptake
80,0
60,0
40,0
20,0
0,0
-20,0
-40,0
0
15
o,
0
50
o,
0
90
o,
0
90
o,
W
W
W
W
in
in
in
in
m
m
m
m
4
,2
,8
,2
in
,1
m
in
Kaempferol
icr
icr
icr
icr
2
g,
m
Quercetin
m
m
m
m
in
m
ea
st
1
g,
-80,0
in
m
ea
st
-60,0
Flavonoids in broccoli
No differences were found between the
heating methods steaming and MW at
one minute, the only culinary interesting
method.
Both methods produced a loss of ≈ 40 %
for Quercetin and ~ 20% for kaempferol.
Highly variable response to different heating methods for vegetables with
respect to different analysis of antioxidant capacity…………………………………….
The influence of home cooking methods (boiling, microwaving, pressure-cooking,
griddling, frying, and baking) on the antioxidant activity of vegetables has been evaluated
in 20 vegetables, using different antioxidant activity assays (lipoperoxyl and hydroxyl
radicals scavenging and TEAC).
Artichoke was the only vegetable that kept its very high scavenginglipoperoxyl radical capacity in all the cooking methods.
The highest losses of LOO. scavenging capacity were observed in cauliflower after boiling
and microwaving, pea after boiling, and zucchini after boiling and frying.
Beetroot, green bean, and garlic kept their antioxidant activity after most cooking
treatments. Swiss chard and pepper lost OH. scavenging capacity in all the
processes.
Influence of cooking methods on antioxidant activity of vegetables.
Jiménez-Monreal AM, García-Diz L, Martínez-Tomé M, Mariscal M, Murcia MA.
J Food Sci. 2009 Apr;74(3):H97-H103.
Highly variable response to different heating methods for vegetables with
respect to different analysis of antioxidant capacity…………………………………….
Celery increased its antioxidant capacity in all the cooking methods, except
boiling when it lost 14%.
Analysis of the ABTS radical scavenging capacity of the different vegetables showed that
the highest losses occurred in garlic with all the methods, except microwaving.
Among the vegetables that increased their TEAC values were green bean, celery, and
carrot after all cooking methods (except green bean after boiling). These 3 types of
vegetables showed a low ABTS radical scavenging capacity. According to the method of
analysis chosen, griddling, microwave cooking, and baking alternately produce the lowest
losses, while pressure-cooking and boiling lead to the greatest losses; frying occupies an
intermediate position.
In short, water is not the cook's best friend when it comes to preparing
vegetables.
Influence of cooking methods on antioxidant activity of vegetables.
Jiménez-Monreal AM, García-Diz L, Martínez-Tomé M, Mariscal M,
Murcia MA.
J Food Sci. 2009 Apr;74(3):H97-H103.
Highly variable response to different heating methods for
vegetables with respect to different analysis of antioxidant
capacity…………………………………….
20
10
0
-10
Boiling
Pressure
-20
Baking
Microwave
-30
Griddling
Frying
-40
-50
-60
-70
Lipidscavenging, LOO radical,
% change from raw control
Highly variable response to different heating methods for
vegetables with respect to different analysis of antioxidant
capacity……
0
20
10
-5
-10
-15
-20
Series1
artichoke
asparagus
beetroot
broad been
broccoli
brussel sprouts
cauliflower
carrot
celery
eggplant
garlic
green bean
leek
maize
onion
pea
pepper
spinach
swiss chard
zucchini
0
-10
-30
-20
-40
-25
-50
-30
-60
-35
-70
Lipidscavenging, LOO radical, %
change from raw control
Median all vegetables
Lipid-scavenging, LOO radical, %
change from raw control
MW, individual vegetables
Series1
Highly variable response to different heating methods for
vegetables with respect to different analysis of antioxidant
capacity…………………………………….
60
40
20
Boiling
0
Pressure
Baking
-20
Microwave
Griddling
-40
Frying
-60
-80
-100
Scavenging OH radical, % change from raw
control
Highly variable response to different heating methods for
vegetables with respect to different analysis of antioxidant
capacity…………………………………….
0
60
-2
40
-4
20
-6
-8
Series1
-20
-10
-40
artichoke
asparagus
beetroot
broad been
broccoli
brussel sprouts
cauliflower
carrot
celery
eggplant
garlic
green bean
leek
maize
onion
pea
pepper
spinach
swiss chard
zucchini
0
Series1
-12
-60
-14
-80
-16
Scavenging OH radical, %
change from raw control,
median all vegetables, all
heating methods
Scavenging OH radical, % change from
raw control, individual vegetables, MW
Highly variable response to different heating methods for
vegetables with respect to different analysis of antioxidant
capacity…………………………………….
250
200
150
boiling
100
pressure
baking
Microwave
50
griddling
frying
0
-50
-100
ABTS anion radical scavenging, % change from raw control
Highly variable response to different heating methods for
vegetables with respect to different analysis of antioxidant
capacity…………………………………….
200
20
15
150
10
100
Series1
5
0
Series1
50
0
-5
-50
ABTS anion radical scavenging, %
change from raw control, mean all
vegetables, all heating methods
ABTS anion radical scavenging, %
change from raw control, individual
vegetables, MW
Dannelse af toxiner ved opvarmning
Oxidation
af
kolesterol
Acrylamid
Heterocykliske
aminer (HCAs)
Polycykliske
aromatiske
hydrocarboner
(PAHs).
Advanced
Glycation
Endproducts
Dannelse af toxiner ved opvarmning
Acrylamid
Acrylamide…..
.
Effects of consumer food preparation on acrylamide
formation.
Jackson LS, Al-Taher F. Adv Exp Med Biol. 2005;561:447-65
Source U.S. Food and Drug Administration, National Center for Food Safety and Technology (NCFST), 6502 S. Archer Rd.,
Summit-Argo, IL 60501, USA. [email protected]
Abstract
Acrylamide is formed in high-carbohydrate foods during high temperature
as frying, baking, roasting and extrusion. Although acrylamide is known
to form during industrial processing of food, high levels of the chemical
have been found in home-cooked foods, mainly potato- and grain-based
products.
This chapter will focus on the effects of cooking conditions (e.g.
time/temperature) on acrylamide formation in consumer-prepared foods,
the use of surface color (browning) as an indicator of acrylamide levels
in some foods, and methods for reducing acrylamide levels in homeprepared foods.
As with commercially processed foods, acrylamide levels in homeprepared foods tend to increase with cooking time and temperature.
Acrylamide…………
In experiments conducted at the NCFST, acrylamide levels in cooked food
depended greatly on the cooking conditions and the degree of "doneness", as
measured by the level of surface browning.
• French fries fried at 150-190 ˚C for up to 10 min had acrylamide levels of 55 to
2130 microg/kg (wet weight), with the highest levels in the most processed
(highest frying times/temperatures) and the most highly browned fries.
• "dark" toasted bread slices had 43.7-610.7 microg/kg wet weight, compared to
"light" at 8.27-217.5 microg/kg or "medium" at 10.9-213.7 microg/kg
•Analysis of the surface color by colorimetry indicated that some components of
surface color ("a" and "L" values) correlated highly with acrylamide levels.
•Soaking raw potato slices in water before frying was effective at reducing
acrylamide levels in French fries.
•Additional studies are needed to develop practical methods for reducing
acrylamide formation in home-prepared foods without changing the acceptability
of these foods.
The effect of domestic preparation of some potato
products on acrylamide content.
Michalak J, Gujska E, Klepacka J. Plant Foods Hum Nutr (2011) 66:307–312
Source Food Science Department, University of Warmia and Mazury, ul. Heweliusza 6, Olsztyn, Poland. [email protected]
Abstract
The influence that food heating has on the concentration of acrylamide in home-cooked potato dishes prepared
by high-temperature, such as pan-frying, deep-frying, roasting and microwave heating was analyzed.
The experiment was performed with commercially available deep-frozen par-fried French fries and
deep-frozen par-fried potato products other than French fries (cubes, wedges, noisettes, pancakes).
Acrylamide was found in all deep-frozen par-fried French fries and other deep-frozen par-fried potato products
before domestic preparation. The mean level of acrylamide content in all frozen potato products before
preparation was found to be 322 μg/kg. Potato products were then prepared at 180 °C for 3 min and at 220 °C for 10 min.
After domestic preparation (roasting, pan-frying, deep-frying and microwave heating) it was found that the
level of acrylamide in all products increased. Acrylamide content in the analyzed samples significantly increased
as the temperature and time of processing increased.
The statistical analysis showed significant differences (P < 0.05) for acrylamide content as
a function of food preparation. The level of acrylamide increased with the increased heating temperature and heating time.
Additionally, the preparation method of roasting was significantly
lower in acrylamide content (P < 0.05)
than the preparation method of microwaving although both preparation
methods used the same conditions (time and temperature).
These results suggest that microwaving might be more favourable
to the formation of acrylamide
than conventional heating methods, such as roasting.
French fries
Crinkle, n=5 each
Thick-cut, n=3 each
Shoestring, n=3 each
Preparation methods
mean±SD
Before final preparation
410±41
Pan-frying
Deep-frying
Roasting
Microwaving
535±49
539±45
660±51
744±72
Before final preparation
358±81
Pan-frying
Deep-frying
Roasting
Microwaving
527±39
568±41
704±68
763±55
Before final preparation
480±11
Pan-frying
Deep-frying
Roasting
Microwaving
622±10
685±15
817±17
863±25
A Mean ± standard deviation, n = The number of the
same type of products
Acrylamide content of potato products before final preparation
and after different domestic preparation methods , (μg/kg)
Acrylamide content of potato products before final preparation
and after different domestic preparation methods (μg/kg)
Other potato products
Cubes, n= 3 each
Wedges,n=3 each
Noisettes, n=3 each
Pancakes; n=3 each
Preparation methods
Acrylamide (μg/kg)
Pan-frying
341±17
Deep-frying
Roasting
Microwaving
392±18
527±28
679±70
Before final preparation
197±18
Pan-frying
Deep-frying
Roasting
Microwaving
436±18
451±19
588±22
635±30
Before final preparation
337±16
Pan-frying
Deep-frying
Roasting
Microwaving
387±19
405±7
547±9
696±12
Before final preparation
286±2
Pan-frying
Deep-frying
Roasting
Microwaving
437±11
422±13
564±10
694±11
Statistical analysis for the effect of preparation methods
on the acrylamide content of potato products, (μg/kg)
Method
Before final
preparation
Pan-frying
Deep-frying
Roasting
Microwaving
French fries,
n = 11,
Other potato
products,
n = 12,
All products,
n = 23,
B416±61a
C252±72a
D322±154a
B561±53b
C400±46b
D469±109b
B597±67b
C418±53b
D495±114b
B727±71c
C557±51c
D630±100c
B790±64d
C676±59d
D725±107d
A Mean ± standard deviation,
a, b, c, d – Mean in columns followed by the same letter are not significantly different (P ≤ 0.05)
A comparative study of acrylamide formation induced
by microwave and conventional heating methods.
Yuan Y, Chen F, Zhao GH, Liu J, Zhang HX, Hu XS. J Food Sci. 2007 May;72(4):C212-6
Source College of Food Science & Nutritional Engineering, China Agricultural Univ., Beijing, 100083, China.
Abstract
In this study, the formation of acrylamide upon treatment with microwave and conventional heating,
boiling, or frying was investigated in both Asn/Fru and Asn/Glc model systems and in potato chips.
Acrylamide levels were analyzed by HPLC method, which was confirmed by HPLC-MS/MS.
Present results in model systems showed that pH value had a complex influence on the formation of
acrylamide in the 2 systems during both microwaving (600 W) and boiling (120 +/- 1 degrees C).
At pH < 8.0, acrylamide content increased with increasing the pH value, reaching the maximum at pH 8.0
whereas acrylamide content decreased with the increase of pH. Regardless of pH and heating methods,
acrylamide content generally increased with increasing treatment time. Surprisingly, all present results showed
that microwave heating not only induced acrylamide formation in the 2 model systems but also facilitated more
acrylamide to be formed as compared to the boiling method at identical pH and treatment time. At pH 4.0, 8.0, and 10.0,
the larger the microwave power, the more the acrylamide content.
Consistent with the above
observation, treatment of potato chips with microwave heating
for 2.5 to 3.5 min in the range 550 to 750 W similarly
resulted in acrylamide formation.
The highest acrylamide content was formed by 750 W
microwave treatment as 0.897 +/- 0.099 mg/kg, which was
significantly higher than that produced by traditional frying
(180 +/- 1 degrees C), 0.645 +/- 0.035 mg/kg (P < 0.05).
Acrylamide………..
• Less AA with MW in popcorn compared to conventional
heating , but high levels in sugar- varieties Wei Sheng Yan Jiu. 2007
Mar;36(2):220-2
• No formation of AA in cooking of vegetables in MW
•
Shokuhin Eiseigaku Zasshi. 2004 Feb;45(1):44-8.
• Higher formation of AA in selected vegetables if pre-cooked in MW
and then baked, compared to pre-cooking by boiling and then
baking Shokuhin Eiseigaku Zasshi. 2004 Feb;45(1):44-8.
Grillet kød
er farligt
Heterocykliske aminer (HCAs)
HCAs dannes ved meget høj temperatur eller
flammer
Forskellige HCAs dannes, som amino-imidazoquinolin, amino-imidazo-quinoxaliner, aminoimidazo-pyridiner, and aminocarboliner.
HCAs forårsager DNA skader og er formentlig en
faktor I udviklingen af forskelige kræftformer
Polycykliske aromatiske hydrocarboner
(PAHs).
PAHs dannes når fedt drypper ned på grillkullene og ryger…fx.benzo- pyren og
dibenzo[a,h]anthracen, som klistrer sig på
kødets yderside. Kræftfremkaldende.
Fornuftigere brug af grill……..
1.Magert kød.
-drypper mindre fedt og dermed mindre
PAH-fyldt røg
2.Mariner kød før grill´ning
HCA kan reduceres med op til 90 % ,
måske pga barrierefunktion
3.Lavere temperatur
4.Undgå flammer
Flammer forårsager både HCAs og PAHs.
1.Oversteg IKKE kødet.
Fjerkræ , fisk, skaldyr og hakket kød skal
gennemsteges, men ikke mere end det,
brug termometer.
Advanced
Glycation
Endproducts
AGEs
Advanced
Glycation
Endproducts
AGEs
AGEs- advanced glycation endproducts –
Maillard reaction / roasting process
AGEs in food………..
• Worst is high protein-high
fat foods w. endogenous
cellular sugar, producing
”glyco-toxins”:
• Meat, nuts, fats
• Worst is heating w. higher
temperature/ longer time
or ”maturing ” cheese
(parmesan)
J.Am.Diet.Ass.2010;110:911- 16
• Better is acidic
environment (marinade w.
lemon or vinegar)
• Better is shorter time, ie
MW
• Better is grains, vegetables,
pure sugar-foods and milk
products
AGEs in food…..database available
Food item
J.Am.Diet.Ass.2010;110:911-16
AGE, kU/100 g
Butter
Beef, raw
26.480
800
Beef, grilled 4 min
7.416
Beef, Microwaved , 6 min
2.687
Beef, pan fried , olive oil
10.058
BACON, 5 min no oil
91.577
BACON, 3 min MW
9.023
Chicken breast, skinless , raw
769
Chicken breast, skinless , pan fried 13 min, high tp
4.938
Chicken breast, skinless , poached 15 min
1.076
Chicken breast, skinless , microwaved 5 min
1.524
…similar for many other protein rich foods……..
AGEs in food…..database available
J.Am.Diet.Ass.2010;110:911-16
Food item
Lamb, raw/ boiled 30 min
Parmesan vs. cottage cheese 1%
Egg, no oil, all types
Potato boiled vs. French fries
Cashew raw
Pine seeds, raw
Pistacie, raw
Sunflower raw vs. roasted
Peanuts Roasted vs. Roasted in shell
SOY beans roasted and salted
AGE, kU/100 g
826 /1.218
16.900/1.453
43-90
27 / 1522
6.730
11.210
380
2510/4693
8.333/3.440
1.670
Metabolomics, KU LIFE
…………PhD study currently running
LOW AGE- basis diet 5 day before and 2 days after each test meal
Low AGE
Test
meals:
Raw
Minimal processing Bacon
Low preparation time
Milk
Powder
Boiling/steaming
Oil
Vegetables
High AGE
Frying
Grilling
Longer-time cooking
This test meal is ALSO a high-oxysterol meal…….
Oxidation af kolesterol
Intact LDLcholesterol
Oxidized cholesterol,
broken apart – particles
infiltrates arterial wall
LDL cholesterol appears intact in the lower-left corner while oxidized
cholesterol that has broken apart is shown in the
background as it infiltrates the damaged arterial wall along with red blood cells.
www.renderosity.com/.../folder_9/file_435308.jpg
Primary
cholesterol
oxygenation
reactions
mediated by
* cytochrome
P-450 species
*occurring
nonenzymatically
in the presence of
reactive oxygen
species (ROS)
Oxygenation of
cholesterol into
25-OH cholesterol
is catalyzed by
cholesterol 25hydroxylase, a
non-heme iron
protein
Björkhem 2002
Oxycholesterol boosts total
cholesterol levels
Promotes atherosclerosis more than nonoxidized cholesterol.
Fried and processed food, particularly fastfood, contains high amounts of oxycholesterol.
Avoiding these foods and eating a diet rich in
antioxidants: Fresh fruits, berries and
vegetables, may help reduce its levels in the
body.
Added to processed foods, those substances
improve texture, taste and stability
Source: 238th National Meeting of the American
Chemical Society 2009. Zhen-Yu Chen, PhD Chinese
University of Hong Kong
(Photo Credit: Wikimedia Commons)
Alzheimer's and oxidized cholesterol:
Neighbors come together
Lipidomics Gateway (26 August 2009) [doi:10.1038/lipidmaps.2009.20]
An oxidized form of cholesterol alters membrane organization and might disrupt cellular
function in Alzheimer's disease.
Alzheimer's disease is characterized by accumulation of the neurotoxic peptide β-amyloid.
This peptide can oxidize cholesterol to form the oxysterol 7β-hydroxycholesterol 1 (7β-OH).
Although cholesterol in cell membranes brings neighboring phospholipid molecules closer
together, by inducing a partial straightening of their acyl chains, the effect of 7β-OH on
membrane organization is unknown. Now Steven Regen and colleagues report in the
Journal of the American Chemical Society that the condensing effect of 7β-OH is enhanced
compared to that of cholesterol. This produces a membrane reorganization that might help
to explain the enigmatic etiology of Alzheimer's disease.
7β-hydroxycholesterol is produced by oxidation of cholesterol
Mitomo, H., Chen, W.H. and Regen, S.L.
Oxysterol-induced rearrangement of the liquid-ordered phase: a possible link to Alzheimer's disease?.
J. Am. Chem. Soc. (6 August 2009). doi:10.1021/ja904308y
Oxidized cholesterol test feeding
Background: Information on the absorption of cholesterol oxidation
products (COP) from ordinary foodstuff in humans is scarce.
Methods: Five healthy young men were offered a 150 g salami + 150 g
Parmesan+ 135 g bread, a meal naturally rich in COP. Plasma and
lipoprotein COP concentrations were measured over 9 h.
Results: The mean plasma free (nonesterified) COP concentration showed its
maximal increase 3 and 5 h after meal consumption. In contrast, the raise
in plasma total COP concentration began 6 h after the meal with a
maximum at 8 h and was statistically significant for 7·- and 7ßhydroxycholesterol and 7-ketocholesterol.
Conclusion: COP from ordinary foodstuff were absorbed
in the human intestinal tract but differences in the bioavailability of the
single COP compounds were found.
Dr. Jakob Linseisen/ Günther Wolfram Institute of Nutrition Science of the Technical University of Munich, Germany.
Ann Nutr Metab 1998;42:221–230
Peak 3 hrs.
• Alpha- epoxide
• 7- keto :
triple from 75,4 nmol/l at
baseline to 235 nmol/l
• Cholestanetriol
Peak at 5 hrs.
• 7- α – OH- cholesterol
• 7-β – OH- cholesterol
Doubles from 40 nmol/l
to 87 nmol/l
• Cholesterol- β- epoxide
25-OH- Cholesterol
The role of endoplasmic reticulum stress in the progression of
atherosclerosis.
Tabas I. Circ Res. 2010 Oct 1;107(7):839-50.
Source Department of Medicine, Columbia University, New York, NY 10032, USA.
[email protected]
Abstract
Arterial wall stressors may be especially prominent in the settings of
obesity, insulin resistance, and diabetes, all of which promote the clinical
progression of atherosclerosis.
In macrophages, prolonged ER stress triggers apoptosis, leading to plaque
necrosis if the apoptotic cells are not rapidly cleared. ER stress-induced
endothelial cell apoptosis may also contribute to plaque progression.
Another potentially important proatherogenic effect of prolonged ER stress
is activation of inflammatory pathways in macrophages and, perhaps in
response to atheroprone shear stress, endothelial cells.
The role of endoplasmic reticulum stress in the progression of
atherosclerosis.
Tabas I. Circ Res. 2010 Oct 1;107(7):839-50.
Source Department of Medicine, Columbia University, New York, NY 10032, USA.
Prolonged activation of the endoplasmic reticulum (ER) stress
pathway,known as the unfolded protein response (UPR) can lead
to cell pathology and subsequent tissue dysfunction.
Ample evidence that the UPR is chronically activated in
atherosclerotic lesional cells, particularly advanced lesional
macrophages and endothelial cells.
The stressors in advanced lesions that can lead to prolonged
activation of the UPR include oxidative stress, oxysterols,
and high levels of intracellular cholesterol and saturated fatty
acids.
Oxycholesterol- biological effects
Oxycholesterol, may pose the greatest heart
disease risk.
Study on hamsters (Chen, Hong-Kong 2009):
•Diet high in oxycholesterol Vs.
Diet with non-oxidized cholesterol
Outcome :
•Blood cholesterol + 22 % in oxy-cholesterol group
•Greater deposition of cholesterol in the lining of blood-vessels (atherosclerotic
plaques)
Plaques increase the risk for heart attack and stroke.
Oxycholesterol had undesirable effects on artery function:
Reduces the elasticity of arteries, impairing their ability to expand and carry more
blood.
Time-of-year-result, study 1 + 2
Second heating study
T-test May vs. January
p-value
Raw
0,321
MW
0,001
Oven
0,001
Boiling
0,001
Steaming
0,10
Wok
0,008
Induction
0,036
Teflon pan 0,011
Pooling of data, first study
1400.0
1200.0
1000.0
All 3 oven methods were similar: Convection,
hot-air and common electric oven, n=18
Two boiling methods: Water boiling on
electric stove and pressure boiling on electric
stowe, n=12
Three frying methods: Teflon pan, easy slip
800.0
Alpha-Epoxy
7-beta-OH
7-Keto
600.0
Beta-Epoxy
Total oxy
400.0
200.0
0.0
Wok gas,n=6 Induction, n=6
Raw,n=3
All oven,
n=18
Boiling, n=12 Frying,n=18
MW, n=6
Steaming,n=6
Second heating study
Overall result, n=12 raw and n=9 in each group
Overall ranking from
high to low, at
significant p-values:
1. boiling
2. MW
3-6. similar: wok,
steaming, oven,
induction
7. teflon
8. control
Intermediate/ Selected methods heating study
Fig.12. 7-beta-OH-cholesterol
Stepwise regression: group, at p=0,026 and weight
change at P=0,028
Univariate analysis w. Bonferroni at 0,01
*Control significantly different from:
- Boiling, MW and oven
*Wok gas significantly different from:None
*Boiling significantly different from:
- Control, teflon, steaming, induction and oven
*Teflon significantly different from:
- Boiling, MW
*MW significantly different from:
- Control, teflon, steaming, induction, oven
*Steaming significantly different from:
- MW, boiling
* Induction significantly different from:
- Boiling, MW
*Oven significantly different from:
- Control, boiling, MW
Intermediate/ Selected methods heating study
Fig. 13. Total Oxy-cholesterol/Total
COPs
Stepwise regression: Group, at p=
0,024 and weight change p=0,045
Univariate analysis w. Bonferroni at
0,01:
*Control significantly different from:
Boiling, teflon, MW, steaming, oven
*Wok gas significantly different from:
none
*Boiling significantly different from:
- Control, teflon, induction
*Teflon significantly different from:
- Boiling, MW
* MW significantly different from:
- Control, teflon, steaming, induction
* Steaming significantly different from:
- Control, MW
*Induction:- Boiling, MW
*Oven significantly different from:
- Control
Possible to reach high enough levels
of COP with 75°C heated chicken ??
Amount of COP per portion of 150 g edible portion ≈ 50 g dry weight
7-beta -OH, a-epoxy,
nmol
nmol
7- keto,
nmol
b-epoxy,
nmol
Total oxy
cholesterol
nmol
15,74
123,61
23,61
107,75
270,72
Teflon pan 27,50
113,50
57,00
271,50
469,94
MW
90,50
158,00
180,00
532,00
960,00
Boiling
117,01
200,20
205,76
625,31
1148,28
Raw
Added spices…….and a good quality oil
 Organic greek extra- virgin olive oil w.
lemon – 1 tbs. In preparation
 Organic rosemary (Rosmarinus
Officinalis), from
www.Sonnentor.com ≈ 3 tsp. added
before heating
 Organic/bio turmeric (Curcuma) from
www.lebensraum.de ≈ 3 tsp. added
before heating
 Let sit for 15 min before preparation
 Level of spices high, compared to
European tradition, but with fine
taste.
7-betaHydroxycholesterol
after heating with
spices turmeric,
rosemary and olive oil,
n=2
300.0
250.0
200.0
150.0
100.0
50.0
0.0
7-beta-Hydroxycholesterol
1. Slight increase in MW + spices,
2. Large increase in induction + spices,
almost 3-fold from 87 ng/g to 263 ng/g
3. 28% decrease in oven + spices
-compared to the same without spices
Beta-Epoxy-cholesterol
after heating with
antioxidant spices turmeric,
rosemary and olive oil, n=2
500.0
450.0
400.0
350.0
300.0
250.0
200.0
150.0
100.0
50.0
0.0
beta-Epoxycholesterol
1. 58% decreased oxidation in MW + spices,
2. 38 % increase in induction + spices
3. 17% % decreased oxidation in oven + spice
compared to the same without spices
Conclusion
• The study has revealed a significant trend for formation of COPs in
different heating methods of organic chicken breast.
• Study 1:
Wok, teflon pan and Induction = gentle heating
Electric heating = intermediate, regardles of method
Steaming, boiling and microwave = aggressive.
• Study 2:
Teflon (green pan) = gentle
Wok, streaming, oven, induction= intermediate
Boiling, microwave = aggressive
Conclusion
• Findings are highly relvant for public health on
the real large scale…………it is findings who, if
applicated, studied and expanded further – can
contribute to save both lives and quality of lives.
• Alone i EU 25 (ie not worldwide) there is 741.000
coronary heart disease deaths, per year.
• Oxidized cholesterol is thought to be a major
contributing preventable cause.
Konklusion
• INGEN enkle
resultater
eller
handlinger
på området
• VARIATION
Kulhydrater
/stivelse:
hellere kogt
/langtidsbagt
ved lav
temperatur
/ låg på
Grøntsager:
Mange RÅ,
Nogen kan
lide
opvarmning
Proteiner
& fedt:
Så LAV
temperatur og
så KORT tid
som muligt
Tak for i dag
SPØRGSMÅL??
Is it possible to reach high enough levels for
significant clinical result of total COP
with 75°C heated chicken ??
•
Linseisen 1998
= used 8,846 µmol total COP / portion /923 mg cholesterol with salami and
parmesan
•
Emmanuel 1991
= used 28 µmol total COP / portion with spray dried egg powder
•
•
•
•
•
Present study 2011; ranges pr. 150 g edible portion chicken/ est. 33 % DM
Raw
270,72 nmol ≈ 0,271 µmol
Teflon 469,94 nmol ≈ 0,470 µmol
MW
960,00 nmol ≈ 0,960 µmol
Boiling 1148,28 nmol ≈ 1,148 µmol
=
Result : Isothiocyanates in broccoli
Total ITC formation in broccoli after the different heat treaments (nmol/g)
Treatment
0 min
1 min
2 min
4 min
10 min
Raw
3185.4 ±17.5
3178.6 ± 53.0
still raw
231.6 ± 170.2
Green, crisp
121.1±39.3
114,3 ± 29.9
Induction steaming
171,5 ± 53,3
439.7 ± 339.0
Green, crisp
343,6 ± 14,7
41.3 ± 15.0
Green, crisp
31.8 ± 9.8
51.0 ± 1.5
Conventional steaming
2620,7±316,4
430.7 ± 84.2
Green,
crisp/hard
1610,6±1162,4
35.4 ± 4.1
Green, crisp
25.1 ± 3.4
27.7 ± 2.7
Induction cooking
18.8 ± 0.8
65.5 ± 55.7
21.1 ± 0.1
10.4 ± 12.1
Conventional cooking
20.3 ± 1.9
19.1 ± 3.8
18.6 ± 2.6
19.2 ± 2.2
Microwave (900 W)
Mean ± SD: SD are calculated from 2 samples and 2 repeating injections from each sample.
Table 7. Isothiocyanate in broccoli with different heating methods and time.
Treatment
ITC in
broccoli,
nmol/g
(Mean ±
SD)[1]
Percent
enzyme
activity
retained
Texture,
Small
stalk
Texture,
flower
Color
Raw
3185,4 ± 17,5
100
Hard
Hard
Green
Microwave
1000W, 1 min
3178,6 ± 53,0
99,7
Raw
Partially
raw
Green
1000W, 2 min
231,7 ± 170,2
7,2
Crisp
Firm
Green
1000W, 4 min
121,2 ± 39,4
3,8
Soft
Soft
Green
1000W, 10 min
114,3 ± 29,9
3,6
Soft,
burned
Soft
Green
Burned
500W, 8 min
79,4 ± 32,1
2,5
Soft
Soft
Green,
dicolor
150W, 24 min
58,0 ± 8,7
1,8
Very soft
Very soft
Yellow
brown
Induction
steaming
1 min
171,5 ± 53,3
439,75 ±339,0
5,4
13,8
Crisphard
Crisp
Green
2 min
343,6 ± 14,7
41,3 ±15,0
10,8
1,3
Crisp
Crisp
Green
4 min
31,8 ± 9,8
0,9
Firm
Soft
Green
10 min
51,0 ± 1,5
1,6
Soft
Soft
Green,
color loss
Treatment
ITC in
broccoli,
nmol/g
(Mean ±
SD)[1]
Steaming
1 min
2620,7 ± 316,4
430.7 ± 84.2
2 min
Percent
enzyme
activity
retained
Texture,
Small
stalk
Texture,
flower
Color
82,2
13,5
Crisphard
Crisp
Light green
1610,6 ± 1162,4
35.4 ± 4.1
50,5
1,1
Crisp
Crisp
Light green
4 min
25,1 ± 3,4
0,8
Crisp
Firm
Green
10 min
27,7 ± 2,7
0,9
Soft
Soft
Green
Cooking
1 min
20,3 ± 1,9
0,6
Crisp
Crisp
Green
2 min
19,1 ± 3,8
0,5
Crisp
Firm
Green
4 min
18,6 ± 2,6
0,6
Firm
Soft
Green
10 min
19,2 ± 2,2
0,5
Soft
Soft
Green
Induction
cooking
1 min
18,8 ± 0,87
0,5
Crisp
Crisp
Green
2 min
65,5 ± 55,9
2,0
Crisp
Firm
Green
4 min
21,1 ± 0,2
0,6
Firm
Soft
Green
10 min
10,4 ± 12,1
0,3
Soft
Soft
Green,
color loss
Ingemar Bjorkhem: J Clin Invest. 2002 Sep;110(6):725-30.
Do oxysterols control cholesterol homeostasis?
Figure 1
Primary cholesterol oxygenation reactions mediated by different
cytochrome P-450 species or occurring nonenzymatically in the
presence of reactive oxygen species (ROS) (43). The oxygenation
of cholesterol into 25-hydroxycholesterol is catalyzed by
cholesterol 25-hydroxylase, a non-heme iron protein (7). The
quantitatively most important oxysterols present in human
circulation are underlined.
Figure 2
Roles of CYP27 and CYP46 in transport of cholesterol from
extrahepatic organs to the liver. Cholesterol does not pass readily
across the blood-brain barrier, but cholesterol produced in the brain
can be oxidized by CYP46 to form the more soluble species 24Shydroxycholesterol. Likewise, 27-hydroxycholesterol is formed in
other extrahepatic cells and contributes to the net flow of circulating
oxysterols from other organs to the liver
http://lipidlibrary.aocs.org/lipids/chol_der/index.htm
Intermediate/ Selected methods heating study
Fig. 9. 7- Keto;
Regression: NS for group
Univariate analysis w. Bonferroni
at 0.01:
*Control significantly different
from:
- Boiling, teflon, MW, steaming,
oven
*Wok gas significantly different
from: none
* Boiling significantly different
from: Control
*Teflon significantly different
from:
Control, MW
*MW significantly different from:
- Control, teflon, induction
* Steaming significantly different
from:Control
*Induction : MW
*Oven significantly different from:
- Control
Intermediate/ Selected methods heating study
Fig.10.alpha-epoxy
Stepwise regression:
Group, p=0,098 (NS)
Univariate analysis w.
Bonferroni at 0,01:
*Control significantly
different from:None
*Wok gas significantly
different from: None
*Boiling significantly
different from: None
*Teflon significantly
different from: None
*MW significantly
different from: None
*Steaming significantly
different from: None
*Induction different from:
None
*Oven significantly
different from: None
Intermediate/ Selected methods heating study
Fig.11. Beta-epoxy
Stepwise regression: Group, p=0,041
Univariate analysis w. Bonferroni at 0,01:
*Control significantly different from: All, exp.
induction
*Wok gas significantly different from: Control,
*Boiling significantly different from: Control
* Teflon significantly different from: Control,
MW
* MW significantly different from:
- Control, teflon, steaming, induction, oven
* Steaming significantly different from:
–Control, MW
*Induction: MW
*Oven significantly different from:
- Control, MW
Result first /pilot study: Chicken and oxy-cholesterol 5
• All types of heating generated much higher
levels of oxy-cholesterol than was found in
the raw samples.
• The increase in 7- keto and 7β -OH cholesterol were ≈ 2-5 fold and 10-17 fold
by boiling, induction and pan frying
compared to 14-21 fold and 60-80 fold for
oven and MW, respectively.
Discussion, second study
• The top- oxidative heating methods at + 1000 ng/g were
steaming and microwave heating, at 1220,5 ng/g and 1124,8
ng/g respectively.
• This was seen across all 4 subclasses of oxi-cholesterols
measured and thus also for the total value.
• The finding was statistically significant on both ANOVA (p=
0,002), multiple regression (p= 0,03) and univariate analysis
for alpha-epoxy-cholesterol (p= 0,01 compared to several
other heatings) and in univariate analysis compared to wok
gas for beta-epoxy – and total cholesterol
Effects of non-competitive interactions involving organic substances on nutrient bioavailability in plant foods: inhibiting factors
Dietary component
Food sources
Phytate (myo-inositol hexaphosphate) Unrefined cereals, legumes, nuts, oil
plus magnesium, calcium or
seeds
potassium phytate
Main technical influences
Binds certain cations to form
insoluble complexes in gut
Nutritional consequences
Zn, Fe, Ca and probably Mg are poorly
absorbed (Heaney et al. 1991;
Sandberg et al. 1999)
Soyabean protein
Some varieties of soyabeans,
Effect not explicable on basis of
Inhibits Fe and Zn absorption in some
unfermented tofu, textured vegetable phytate content but instead depends varieties. Some contain Fe as
protein
on variety and processing method
phytoferrin, which may be highly
bioavailable (Murray-Kolb et al. 2003)
Polyphenols
Certain cereals (red sorghum),
legumes (red kidney beans, black
beans, black grams), spinach, betel
leaves, oregano
Form insoluble complexes with Fe
Inhibit non-haem-Fe absorption
Some polyphenols inactivate thiamin Reduce thiamin absorption
Bind certain salivary and digestive
enzymes
Reduce digestibility of starch, protein
and lipids
Beverages: tea, coffee, cocoa, red
wine
Enhance excretion of endogenous
protein
Interfere with protein digestibility
(Bravo, 1998)
Oxalic acid
Amaranth, spinach, rhubarb, yam,
taro, sweet potato, sorrel, sesame
seeds, black tea
Oxalates form insoluble complexes
with Ca and possibly Fe
Reduce absorption of Ca and possibly
Fe; increase urinary Ca (Savage, 2002)
Dietary fibre
Unrefined cereals, legumes, nuts, oil
seeds, fruits and vegetables
Lignin and pectin bind bile acids
Reduces absorption of fats, fatsoluble vitamins and carotenoids;
effects on folate bioavailability
inconsistent
Pectins, psyllium and gums retain
water and form viscous solutions in
gastrointestinal tract
Slows gastric emptying and digestion
and absorption of nutrients (Gallagher
& Schneeman, 2001)
Dietary fibres are fermented in large
intestine by microflora
SCFA produced that enhance Ca
solubility (Demigne et al. 1995)
Sorghum, Sorghum bicolor (L.) Moench; red kidney beans, Phaseolus vulgaris; black beans, Glycine max; black gram, Phaseolus mungo; spinach, Spinacia
oleracea; betel, Piper betel; oregano, Origanum vulgare; amaranth, Amaranthus edulis; rhubarb, Rheum rhaponticum; yam, Dioscorea spp.; taro, Colocasia
esculenta var. antiquorum; sweet potato, Ipomoea batatas; sesame, Sesamum orietale.
Effects of non-competitive interactions involving organic substances on nutrient bioavailability in plant foods: enhancing factors
Dietary component
Food sources
Main technical influences
Nutritional consequences
Organic acids (citric, lactic, acetic,
butyric, propionic and formic acids)
Fermented milk products (e.g.
May form soluble ligands with some
yoghurts), vegetables, sauerkraut, soya trace minerals in the gastrointestinal
sauces, fermented cereals (e.g. Tobwa) tract
Ascorbic acid
Citrus fruits and juices
Reduces Fe3+ to more soluble Fe2+;
forms Fe–ascorbate chelate
Enhances non-haem-Fe absorption
(Teucher et al. 2004)
Other fruits: guavas, mango, papayas,
kiwi, strawberries
May increase stability of folate during
food processing and digestion
Counteracts inhibitory effect of phytate
Vegetables: tomato, asparagus, Brussels
sprouts, spinach etc.
Enhance absorption of Zn and possibly
Fe (Sandström, 1997; Teucher et al.
2004)
May enhance folate bioavailability
(McNulty & Pentieva, 2004)
May enhance or inhibit Se absorption,
depending on the chemical form
(Mutanen & Mykkanen, 1985;
Levander, 1987).
Ascorbic acid may also enhance Cr
absorption (Offenbacher, 1994)
Protein
Amount and type (e.g. animal protein) Enhance absorption of Zn, Fe and Cu
form soluble ligands with Zn, Fe and Cu (Bjorn-Rasmussen & Hallberg, 1979;
Turnlund et al.1983; Lönnerdal, 2000)
Increase urinary Ca excretion (Heaney,
2000)
Fat
Oil seeds, nuts
Products of fat digestion+bile salts
solubilize fat-soluble vitamins and
carotenoids in intestinal milieu
Enhance absorption of fat-soluble
vitamins and provitamin A carotenoids
(Yeum & Russell, 2002)
Guava, Psidium guajava L.; mango, Mangifera indica L.; papaya, Carica papaya; kiwi, Actinidia deliciosa; strawberry, Fragaria X ananassa; asparagus, Asparagus
officinalis; spinach, Spinacia oleracea.
Influence of household food processing and preparation methods on bioavailability of nutrients in plant foods
Processing method
Thermal processing
Main technical influences
Nutritional consequences
Releases some vitamins from poorly-digested
complexes
Enhances bioavailability of vitamin B6, niacin, folate and
certain carotenoids
Inactivates heat-labile anti-nutritional factors (e.g.
protease inhibitors, α-amylase inhibitors, lectins,
thiaminases, goitrogens)
Enhances digestibility of proteins and starch
May degrade phytate, depending on temperature
Enhances bioavailability of thiamine and I
Gelatinizes starch
May enhance Zn, Fe and Ca bioavailability
Enhances digestibility
Baking
Induces Maillard browning in foods containing reducing Destroys basic essential amino acids lysine, arginine
sugars
and methionine
Reduces protein quality and protein digestibility
Boiling
Reduces oxalate content
Enhances Ca absorption
Germination and malting
Increases phytase activity via de novo synthesis or
activation of endogenous phytase
Induces hydrolysis of phytate and hence increases Zn,
Fe, Ca, and Mg absorption
Reduces polyphenol content of some legumes (e.g.
Vicia faba)
Enhances non-haem-Fe absorption
Increases α-amylase content of cereals (e.g. sorghum
and millet)
Facilitates starch digestion; may increase non-haem-Fe
absorption through a change in consistency
Village-based milling or home pounding
Reduces phytate content of cereals with phytate
Enhances bioavailability of Zn, Fe, and Ca, although
localized in outer aleurone layer (rice, wheat, sorghum) mineral content simultaneously reduced
or in germ (maize)
Microbial fermentation
Induces hydrolysis of phytate by microbial phytase
Enhances bioavailability of Zn, Fe and Ca
Increases content of organic acids
May form soluble ligands with non-haem-Fe and Zn,
and enhance bioavailability
Microbial enzymes may destroy protein inhibitors that May improve protein quality in maize, legumes,
interfere with N digestibility
groundnuts and pumpkin and millet seeds
Sorghum, Sorghum bicolor (L.) Moench; millet, Achnatherum hymenoides; groundnut, Apios americana Medic.; pumpkin, Cucurbita Pepo.