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Formation, Occurrence and Strategies to Address Acrylamide in Food

Formation, Occurrence and Strategies to Address Acrylamide in Food. Robert Brown, Ph.D. H 2 N. N H 2. C – CH 2 – CH. COOH. O. H 2 N. N. C – CH 2 – CH. O. COOH. Possible mechanism for formation of acrylamide from asparagine. OH. OH. HO. +. O. OH. OH. H 2 N. N.

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Formation, Occurrence and Strategies to Address Acrylamide in Food

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  1. Formation, Occurrence and Strategies to Address Acrylamide in Food Robert Brown, Ph.D.

  2. H2N NH2 C – CH2 – CH COOH O H2N N C – CH2 – CH O COOH Possible mechanism for formation of acrylamide from asparagine OH OH HO + O OH OH

  3. H2N N C – CH2 – CH O COOH H2N N C – CH2 – CH2 O H2N C – CH = CH2 O Possible mechanism for formation of acrylamide from asparagine Maillard Products EA~25 - 50 kcal/mole - CO2 Beta-elimination EA ~70 kcal/mole

  4. Insights • The chemical pathway leading to AA is a low yield pathway with high activation energy.

  5. Summary of Acrylamide Values in Food

  6. Calories and Nutrient Intake • Foods tested and found to contain acrylamide (so far) constitute: • 38% of calories • 33% of carbohydrates • 36% of fiber • 28% of fat • 20% of calcium • 47% of iron • 25 to 35% of other micronutrients • 15% of vitamin A • 34% of vitamin E • 22 to 44% of B, C and folate vitamins

  7. Insights • The chemical pathway leading to AA is a low yield pathway with high activation energy. • The AA question affects a large fraction of the food supply, calories and nutrients commonly consumed.

  8. Dealing With The Acrylamide Issue Remove Acrylamide after formation Remove Reactants Disrupt Reaction Toxicology

  9. Dealing With The Acrylamide Issue Remove Acrylamide after formation Remove Reactants Disrupt Reaction Toxicology

  10. Sample Acrylamide concentration (µg/kg) SNFA result (µg/kg) Baking potatoes raw GC-MS <10 LC-MS-MS nd <30 Boiled <10 nd Chipped & fried 310 350 Acrylamide formation influenced by starting raw material King Edward potatoes raw <10 Nd <30 boiled <10 Nd Chipped & fried 2800 3500 Frozen frying chips as sold 200 100 Cooked 3500 3500 Over cooked 12800 12000 Summary table of results - CSL

  11. Asparagine in Various Crops Cheese 40 – 300 Asparagus 5.4 – 108 Cocoa (raw) 30.9 - roasted @ 125C 14.5 - roasted @ 135C 9.4 Potato 0.5 – 10 mg/g Rye 0.2 – 2.8 Wheat 0.02 – 2 Corn 0.6 – 1 Also in peanuts, soybeans, onions, coffee, tomatoes, fruits, etc. From Ellin Doyle, Ph.D., Food Research Inst., U. Wisc.

  12. 30000 20000 20000 AA (ppb) 10000 1.0 0.8 0.8 0 0.6 GLU GLU 0.4 0.0 0.0 0.0 0.2 0.2 0.1 0.1 0.2 0.2 0.2 0.0 0.3 ASN 0.4 0.5 Surface Plot of AA/Substrate Relationship AA = -245.2 - 427.9*(ASN) + 460.1*(GLU) + 60582.7*(ASN)*(GLU) R-Squared = .97

  13. Insights • The chemical pathway leading to AA is a low yield pathway with high activation energy. • The AA question affects a large fraction of the food supply, calories and nutrients commonly consumed. • The chemical reaction of asparagine and glucose is second order when the substrates are approximately equal. When one is substantially lower it becomes rate-limiting.

  14. Dealing With The Acrylamide Issue Remove Acrylamide after formation Remove Reactants Disrupt Reaction Toxicology

  15. Sample Acrylamide concentration (µg/kg) SNFA result (µg/kg) Baking potatoes raw GC-MS <10 LC-MS-MS nd <30 Boiled <10 nd Chipped & fried 310 350 Yield of acrylamide increases substantially with browning King Edward potatoes raw <10 Nd <30 boiled <10 Nd Chipped & fried 2800 3500 Frozen frying chips as sold 200 100 Cooked 3500 3500 Over cooked 12800 12000 Summary table of results - CSL

  16. Effect of Temperature on AA Formation 1% gluc, 0.2% asn in sodium phosphate at pH 7.0 for 15 minutes.

  17. AA Formation at 15 Minutes as a function of Temperature 20000 (.07930*(Temp-383)) AA = 442.3 * e 15000 Acrylamide (ppb) 10000 5000 0 380 400 420 440 Temperature (Kelvin)

  18. Insights • The chemical pathway leading to AA is a low yield pathway with high activation energy. • The AA question affects a large fraction of the food supply, calories and nutrients commonly consumed. • The chemical reaction of asparagine and glucose is second order when the substrates are approximately equal. When one is substantially lower it becomes rate-limiting. • AA formation is temperature critical and occurs well below temps at which food is commonly cooked. It will probably not be possible to cook food without forming at least some AA.

  19. Effect of pH on Acrylamide Formation

  20. Prevent Asparagine and Glucose Reaction The Idea + + Raw Reaction Cooking Reduced Food Inhibitor Acrylamide Watchout: The inhibitor(s) must be food safe.

  21. k k k m e l a n o i d i n s 1 2 3 g l u c o s e I 1 I 2 ( c o l o u r ) a c r y l a m i d e k , k , . . . m n k , k , . . . . 4 5 f l a v o u r v o l a t i l e s Kinetic model (Wedzicha & Mottram) Rate constants Allow the rate of each step to be quantified in terms of reaction variables: pH, T, concentration of glucose and amino acid

  22. Dealing With The Acrylamide Issue Remove Acrylamide after formation Remove Reactants Disrupt Reaction Toxicology

  23. Remove After Formation • Supercritical CO2 • removes everything but destroys the product • UV light • no effect, several wavelengths including visible

  24. Dealing With The Acrylamide Issue Remove Acrylamide after formation Remove Reactants Disrupt Reaction Toxicology

  25. Relative Exposure to Acrylamide in U.S. Food French Fries & Potatoes Coffee Cakes Dried Foods Pop Corn Salty Snacks Chocolate Products Nuts/Seeds/Butters Breads Potato Chips Cereal Biscuit / Cookies All Other Foods

  26. Relative Exposure – All Potato Products Zero Coffee Cakes Dried Foods Pop Corn Salty Snacks Chocolate Products Nuts/Seeds/Butters Breads Cereal Biscuit / Cookies All Other Foods

  27. Food For Thought • The notion of “carcinogens” in food is not new (cooked meat, NAS report, “Ames/Gold” list). • Humans have eaten these foods for millennia. • There are no obvious “quick fixes” or magic bullets. Much of what we have learned looks interesting, but the solution has not been found.

  28. Feasibility Analysis • Removal of substrates must take into account kinetics of formation along with importance of other constituents. • Low temperature intervention will require development of new cooking methods. Some foods will be impossible to cook at low temperature. • No universal “magic bullets” have been found. Addition of substances may work for some products but with variable efficacy. There is no precedent for an intervention into the food supply on this scale

  29. Final Thoughts • The issue affects a large portion of the food supply. Lowering acrylamide in one or a few foods has no effect- everything must be changed. • Food cooked at home and in restaurants is a big challenge, and a significant source of acrylamide exposure. • What does victory look like? Given the magnitude of change to the food supply we need to fully understand two things: • the nature of the low dose hazard to humans, and • the impact of any proposed interventions. Are there any unintended consequences to public health?

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