comparison of ages produced by different cooking methods - 2013

Comparison of AGEs produced

by different cooking methods

November 08, 2013

NONGSHIM R&D

Heejung An

NONGSHIM R&D SPEED DIFFERENCE PARTNERSHIP

INDEX

Definition of AGEs

Formation and Structure of AGE

Foods and AGEs

Advanced glycation products in foods

Inhibition of AGE formation (AGE-less diet)

Conclusions


Definition of AGEs

3

AGEs

Amino-carbonyl reaction, Early glycation products, intermediate glycation products,

advanced glycated end-products

Non-enzymatic reaction between the carbonyl group of a reducing sugar with

proteins and lipids

Sugar binds to protein(non-enzymatic glycation) and subsequently form irreversible

crosslinks between proteins

Maillard Reaction products formation

Advanced glycation end products(CML)

formation

Reaction during cooking


Structure of AGEs

4

AGEs

Intermediate products in the formation of an AGE are known as Amadori, Schiff base,

and Maillard products.

Further nonoxidative and/or oxidative modification leads to molecular

rearrangements followed by generation of AGEs.


Structure of AGEs

5

AGEs

Glycation of proteins and lipids result in denaturation, browning, and cross-linking of

the targeted proteins.

Stable AGE compounds such as CML and MG produced by the reaction of highly

active intermediate carbonyl groups with amino-acid functional groups on proteins.

degradation

Early glycation production

Intermediate glycation products

Amino-carbonyl reaction

AGEs

CML= carboxymethyllysine GOLD = glyoxal lysine dimer MOLD = methylglyoxal lysine dimer DOLD= 3-deoxyglucosone lysine dimer CEL = carboxyethyllysine MG = methyl glyoxal


Formation of AGEs

6

AGEs

AGE formation on lysine and arginine functional groups on proteins

Outside of the body, AGEs may be formed by heating (e.g., cooking); Inside the body

AGEs may be formed as a result of normal metabolism and aging

*carcinogenic

*Asparagine

cf. acrylamide formation


Food and AGEs

7

AGEs in the Modern Diet

- Dry heat cooking & food processing

- Maillard/browning reaction

- Enhance taste, aroma, appearance

Formation of AGEs in foods

- Processing time and temperature

- processing type(frying, roasting, grilling, baking)

- Reheating process(fast food)


Advanced glycation end products in foods

Objectives

- to determine the AGE content of commonly consumed foods and to evaluate the

effects of various methods of food preparation on AGE production

Methods

- Foods from cafeteria, local restaurants or supermarkets or prepared

- Foods subjected to standard cooking methods such as boiling, broiling, deep frying,

oven-frying, and roasting

- AGE contents tested with enzyme-linked immunosorbent assay, expressed as AGE

kilounits/100g food based on CML content



Meats and meat substitutes Cooking method AGEs content

(ku/100g)

Beef

Boiled 1538

Roasted 6071

Grilled 7416

Broiled 11,270

Pan-fried 10,058

Poultry

Poached 1101

Pan-fried 4938

Deep-fried (breaded) 9722

Roasted & BBQ(skin) 18,520

Pork

Pork roasted 3544

Pork pan-fried 4752

Bacon(microwave) 9023

Bacon fried 91,557

<AGE contents of Meats based on CML(carboxymethylysine) content>



Fish/seafood Cooking method AGE content

(ku/100g)

Salmon

Microwave 912

Boiled 1082

Broiled 3347

Pan-fried 3083

Broiled 4334

Eggs

Poached 90

Omelet, pan 507

Scrambled, pan 243

Egg yolk 1680

Fried 2749

<AGE contents of fish/Eggs based on CML(carboxymethylysine) content>



AGE content of Selected cheeses

AGE(kU/30g)

0

1000

2000

3000

4000

5000

6000

Parmesan American American,low fat

Cheddar Cheddar,2%

Cheddar,1%



AGE content of Selected Fats

0

500

1000

1500

2000

Butter Margarine Olive oil Nuts / Seeds(Raw)

Avocado

AGE(kU/15g)



High –AGE Foods

Food group

Meat

Beef > Poultry> fish > eggs

Roasted, grilled, broiled, fired> poached, Steamed, stewed, braised, etc

High-fat > lower- fat

Cheese High-fat, aged, processed > lower-fat

Fat, oils Butter, cream cheese > margarine,

Mayonnaise, oils, nuts



AGE content of foods as determined by CML levels

- meat category prepared by similar methods

: beef > poultry> pork> fish > eggs

: relatively highly reactive amino-lipids, reducing sugars in lean muscle

- meat > fats/oils

: fats contain more dAGE(kU/g), but meats contribute more dAGE

: served in larger portions than fats

- processed cheese > uncooked cheese

: pasteurization and/or holding times(curing or aging processes)

- higher- fat spread > oils, nuts

: various extraction and purification procedures involving heat and dry



0

1000

2000

3000

4000

5000

6000

7000

Beef Chicken Salmon Egg

Dry heatMoist heat

Dry Heat vs. Moist Heat



Animal vs. Vegetable Protein

0

1000

2000

3000

4000

5000

6000

7000

Beef Chicken Salmon Egg Beans Vegeburger



Food group Food Item AGE content (ku/serving)

Grains

Whole wheat bread 36

Biscuit, oven baked 441

Crackers 653

Chips 865

Biscotti cookie 966

Fruits/Vegies

Apple, fresh 13

Apple, baked 45

Eggplant, raw 116

Eggplant, grilled 256

Milk

Milk, fat free 2

Milk, whole 12

Evaporated milk 86

Cocoa packet 656

<AGE contents of carbohydrate based on CML(carboxymethylysine) content>



Lower –AGE Foods

Food group

Grains Crackers, chips, cookies > breads,

Oatmeal, boiled/steamed grains

Fruits, Veges

Roasted, grilled > fresh, steamed

Milk Hot cocoa mix, evaporated milk > milk,

Yogurt, ice cream, pudding



Chicken AGE(kU per 90g)

Raw 700

Poached/ boiled / steamed 1,000

Roasted 4,850

Broiled / grilled 4,800

Deep frying 7,760

<Choose cooking methods that inhibit formation of AGEs>

Effect of cooking method on AGE formation in foods

: scrambled eggs (medium-low heat vs. high heat)

higher temperature and lower moisture higher dAGE levels



<Use ingredient that inhibit formation of AGEs>

Water

- moist heat cooking

Acid

- Lemon juice, vinegar, tomato juice, wine, etc.

- Use in marinades & cooking liquids

AGE –Less but not tasteless

- Increase herbs, spices, seasonings

- Add sauces



Summary

- Limit new AGE formation in foods

: brief heating time, low temperature, high moisture, and/or

pre-exposure to an acidified environment

- Reduce intake of dAGE

: fish, legumes, low-fat milk, vegetables, fruits, and whole grains

: solid fat, fatty meats, full-fat dairy, highly processed foods

- Prevent the formation of new dAGEs during cooking

: cooking with moist heat, using shorter cooking times, cooking at

lower temperatures

: use of acidic ingredients such as lemon juice or vinegar


Conclusions

The “AGE –less” diet

- Similar to Asian cuisine

: Vegetables, fruits, whole grains, legumes, low-fat diary,

fish/seafood, olive oil, nuts

- Use lemon, wine, tomatoes, etc. in marinades & cooking liquids

Educating consumers

- less sugar, lower calorie foods

- less processed meal

- AGE-less cooking methods

- Ingredients to limit AGE formation


Future studies

Ongoing studies

- Expand dAGE database

- Investigate additional methods to reduce AGE formation in cooking

& food processing

- refine recommendations for safe intakes

Future Directions

- Investigate methods to analyze AGE contents in Korean foods

- Monitor CML contents of various food categories

comparison of ages produced by different cooking methods - 2013

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