Acrylamide Formation Exposure Possible Reduction Strategies by Barbara

Acrylamide: Formation, Exposure, Possible Reduction Strategies by Barbara Petersen Exponent, Inc. Materials and conclusions have been drawn from the October 2002 JIFSAN workshop, the FAO/WHO report on acrylamide, and presentations at the US FDA Food Advisory Committee meetings (Dec 2002, Feb 2003)

Workshop: Acrylamide in Food: Scientific uncertainties, issues and research strategies (Oct 2002) Ø Ø Funded: Participants fees from government, industry and academia 5 working groups considered current knowledge, identified gaps and recommended future research needs

Acrylamide (AA) in Food: Scientific uncertainties, issues and Research strategies: Working Groups Ø Ø Ø Mechanisms of formation Analytical methodology Exposure and biomarkers Toxicology and metabolic consequences Risk communication

Research priorities Ø Research priorities are summarized along with the meeting working papers on – http: //www. jifsan. umd. edu

Exposure to Acrylamide: Preliminary estimates Ø Exposure to Acrylamide (AA) – Preliminary estimates available from international sources including FAO/WHO using different models and different study types

Initial international estimates of mean exposure Ø Ø Sweden: 40 µg/person/day (0. 67 µg/kgbwday, 60 kg bw/person) FAO/WHO – June 2002 Ø Assumptions: Swedish residue data and food consumption data from U. S. , the Netherlands, Norway, Australia, Sweden, and from IARC EPIC Study Ø Probabilistic Modeling as well as Point Estimate Methods Ø Long-Term Exposure Estimates Ø 0. 3 - 0. 8 µg/kgbw-day

Swiss duplicate diet study Ø . 28 mcg/kg bw/day (vs WHO. 3 -. 8 mcg/kg BW/day) – Breakfast 8% – Lunch 21% – Dinner 22% – Snacks 13% – Coffee 36%

US FDA conducted multiple analyses Ø Ø Ø Several different surveys for food consumption including data from the USDA’s Continuing survey of food intake conducted in 1994 -96, 98 Acrylamide levels from FDA testing plus evaluation of the impact on intake if levels change in foods Different models including Monte Carlo modeling to incorporate more realistic estimates of the probability of occurrence of residues

Summary of Acrylamide Values in Food

Factors applied to food Acrylamide concentration Ø Ø Ground Coffee/24 = Coffee as Consumed (Experimentally Derived) Instant Coffee Crystals/60 = Instant Coffee as Consumed (3 g Coffee/6 oz Cup) Dry Soup Mix/12 = Soup as Consumed (15 g Soup Mix/6 oz Cup) Dry Cocoa Powder/10 = Cocoa as Consumed (17 g Cocoa Powder/6 oz Cup)

US FDA estimates of intake Acrylamide Intake of Population (ages 2 and older) Mean intake =0. 37 µg/kg body weight/day

Acrylamide Intake Distribution CSFII 1994 -96, 1998; 2+ Population

Contribution by food category (for FDA-Tested Foods)

Contribution by food category (for FDA-Tested Foods (continued)

What-If Scenarios Ø Ø Ø Effect of Mitigation Measure on Population Mean Acrylamide Intake Set Acrylamide Levels in Chosen Foods to 0 µg/kg Rerun the Model

What-If Scenarios CSFII, 1994 -96, 98, 2+ Population Ø Ø Population Mean=0. 37 µg/kgbw-d Remove Acrylamide from French Fries – Mean – 0. 26 µg/kgbw-d Ø Remove Acrylamide from Snack Foods – Mean – 0. 31 µg/kgbw-d Ø Remove Acrylamide from Breakfast Cereal – Mean – 0. 33 µg/kgbw-d Ø Remove Acrylamide from Coffee – Mean – 0. 34 µg/kgbw-d

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

Summary of FDA intake assessments Ø Ø Ø Mean Population Acrylamide Intakes Consistent with Previous Exposure Estimates Greatest Contributors to Mean Population Acrylamide Intake are the Same for all tested scenarios Some Foods with Lower Levels Contribute Appreciably to the Overall Mean Population Intake because they are Commonly Consumed No One Food Accounts for the Majority of the Mean Population Intake. Significant potential for disrupting nutritional quality of the diet

Mechanisms of Acrylamide formation that have been studied X X Acrylic Acid Acrylamide carbonyl Asparagine Acrolein

Effectiveness of Amino Acids and Dextrose to Form Acrylamide Model System + Potato Starch + Water Amino acid Reducing sugar Variety of ingredients fry Measure Acrylamide l Acrylamide Formation – – Potato starch + dextrose Potato starch + asparagine Potato starch + dextrose + asparagine <50 ppb 117 ppb 9270 ppb –Alanine <50 ppb –Aspartic A. <50 ppb –Lysine <50 ppb –Threonine <50 ppb –Glutamine 156 ppb <50 ppb 9270 ppb l. Other Amino Acids Arginine Cysteine Methionine Valine Asparagine

Dose/Response: Dextrose Asparagine at 1. 25%

Conclusions from initial research reports Ø Ø Ø Asparagine is the major source of acrylamide formation in foods. Carbonyl source (reducing sugars) is required in the reaction. Oil oxidation products and starch do not appear to be significant factors in acrylamide formation.

Impact of Potato variety on AA Levels (from D. Mottram, U. Reading) Sample Acrylamide concentration (µg/kg) GC-MS LC-MS-MS Baking potatoes raw <10 nd Boiled <10 Chipped & fried 310 King Edward potatoes raw <10 nd 350 boiled Chipped & fried Frozen frying chips as sold <10 2800 Nd 3500 200 100 Cooked Over cooked 3500 12800 3500 12000 Nd SNFA result (µg/kg) <30 Acrylamide formation <30 influenced by starting raw material

Asparagine in various crops Cheese 40 – 300 Asparagus 5. 4 – 108 Cocoa (raw) 30. 9 - roasted @ 125 C 14. 5 - roasted @ 135 C 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.

Impact of browning on AA levels (from D. Mottram, U. Reading) Sample Baking potatoes raw Acrylamide concentration (µg/kg) GC-MS LC-MS-MS SNFA result (µg/kg) <10 <30 nd Boiled <10 Chipped & fried 310 King Edward potatoes raw <10 nd 350 boiled Chipped & fried Frozen frying chips as sold <10 2800 Nd 3500 200 100 Cooked Over cooked 3500 12800 3500 12000 Nd Yield of acrylamide increases substantially <30 with browning

Effect of temperature on AA formation 1% gluc, 0. 2% asn in sodium phosphate at p. H 7. 0 for 15 minutes.

20000 AA Formation at 15 Minutes as a function of Temperature 10000 5000 0 Acrylamide (ppb) 15000 AA = 442. 3 * e(. 07930*(Temp-383)) 380 400 420 Temperature (Kelvin) 440

Effect of p. H on Acrylamide formation

Prevent asparagine and glucose reaction The Idea Raw Food + Reaction Inhibitor + Cooking Reduced Acrylamide Watchout: The inhibitor(s) must be food safe for long term (daily) intake from multiple food sources and should not impact nutritional status.

Acrylamide Precursors – Where to Intervene Ø Reducing levels of precursors: – Asparagine – Reducing sugars – For example: by selecting different varieties of foods or by different storage or processing procedures

Asparaginase reduces Acrylamide in Cooked Potato Products Potato Product Acrylamide (ppb) Control Asparaginase Microwaved snack 20, 500 % Reduction 1 >99 164 1 Calculated as (control – asparaginase treated)/control x 100.

Asparaginase Experiment on Potato Product Washed Russet Burbank Potatoes Boil for 1 hour Blend flesh 1: 3 with distilled water 45 min @ RT Asparaginase-treated Control Microwave @ 2 min intervals for total of 10 min. Highly Cooked to Maximize Acrylamide Formation (both control and asparaginase-treated products were dry and brown)

Impact of treating with Asparaginase Ø By treating with asparaginase there was a 99% reduction in the levels of acrylamide in the potato mixture following the use of the microwave

Remove after formation – overview of some preliminary research Ø Supercritical CO 2 – removes everything but destroys the product Ø UV light – no effect at several wavelengths including visible

Insight and recommendations for Next Steps Ø Ø Ø The concerted research and actions by government, industry and academia have resulted in rapid progress towards understanding the mechanisms of formation in food The notion of “carcinogens” in food is not new (cooked meat, US National Academy of Sciences Report 1), research by Lois Gold & Bruce Ames and in numerous research articles Humans have eaten these foods for millennia 1 National Research Council, 1996. Carcinogens and Anticarcinogens in the Human Diet, ‘A comparison of naturally occurring and synthetic substance. National Academy Press.

Feasibility of reducing levels Ø Ø Removal of substrates must take into account kinetics of formation along with importance of other constituents Preparing foods by cooking at such low temperatures willl require development of new cooking methods. Some foods will be impossible to prepare without temperatures that are high enough to form acrylamide. Addition of substances may work for some products but its too early to evaluate efficacy; could cause major changes in the foods There is no precedent for an intervention into the food supply on this scale; potential to alter nutritional and/or safety aspects of food

Concluding remarks Ø Ø The issue affects a large portion of the food supply. Lowering acrylamide in one or a few foods has little effect on long term intakes - many foods would need to be altered. Food cooked at home and in restaurants represent significant source of acrylamide exposure and would be less amenable to intervention strategies.

Concluding remarks (continued) Ø Before any interventions are proposed, 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?

Additional information Ø Copies of the presentation and or the original references/presentations can be provided on request to Barbara Petersen (bpetersen@exponent. com)