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)  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  Mechanisms of formation  Analytical methodology  Exposure and biomarkers  Toxicology and metabolic consequences  Risk communication

Research priorities  Research priorities are summarized along with the meeting working papers on –

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

 Sweden:40 µg/person/day (0.67 µg/kgbw- day, 60 kg bw/person)  FAO/WHO – June 2002  Assumptions: Swedish residue data and food consumption data from U.S., the Netherlands, Norway, Australia, Sweden, and from IARC EPIC Study  Probabilistic Modeling as well as Point Estimate Methods  Long-Term Exposure Estimates  µg/kgbw-day Initial international estimates of mean exposure

Swiss duplicate diet study .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  Several different surveys for food consumption including data from the USDA’s Continuing survey of food intake conducted in , 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  Ground Coffee/24 = Coffee as Consumed (Experimentally Derived)  Instant Coffee Crystals/60 = Instant Coffee as Consumed (3g Coffee/6oz Cup)  Dry Soup Mix/12 = Soup as Consumed (15g Soup Mix/6 oz Cup)  Dry Cocoa Powder/10 = Cocoa as Consumed (17g Cocoa Powder/6oz Cup)

US FDA estimates of intake Acrylamide Intake of Population (ages 2 and older) Mean intake =0.37 µ g/kg body weight/day

Acrylamide Intake Distribution CSFII , 1998; 2+ Population

Contribution by food category (for FDA-Tested Foods)

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

What-If Scenarios  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, , 98, 2+ Population  Population Mean=0.37 µg/kgbw-d  Remove Acrylamide from French Fries –Mean – 0.26 µg/kgbw-d  Remove Acrylamide from Snack Foods –Mean – 0.31 µg/kgbw-d  Remove Acrylamide from Breakfast Cereal –Mean – 0.33 µg/kgbw-d  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  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

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

Effectiveness of Amino Acids and Dextrose to Form Acrylamide Acrylamide Formation –Potato starch<50 ppb –Potato starch + dextrose<50 ppb –Potato starch + asparagine117 ppb –Potato starch + dextrose + asparagine9270 ppb Potato Starch + Water Amino acid Reducing sugar Variety of ingredients + fry Measure Acrylamide Model System Other Amino Acids –Alanine<50 ppbArginine<50 ppb –Aspartic A.<50 ppbCysteine<50 ppb –Lysine<50 ppbMethionine<50 ppb –Threonine<50 ppbValine<50 ppb –Glutamine156 ppbAsparagine 9270 ppb

Dose/Response: Dextrose Asparagine at 1.25%

Conclusions from initial research reports  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) Over cooked 3500 Cooked Frozen frying chips as sold Chipped & fried Nd<10boiled <30Nd<10 King Edward potatoes raw Chipped & fried nd<10Boiled <30 LC-MS-MS nd GC-MS <10 Baking potatoes raw SNFA result (µg/kg) Acrylamide concentration (µg/kg) Sample Acrylamide formation influenced by starting raw material

Asparagine in various crops Cheese 40 – 300 Asparagus 5.4 – 108 Cocoa (raw) C C 9.4 Potato 0.5 – 10 mg/g Rye 0.2 – 2.8 Wheat0.02 – 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) Over cooked 3500 Cooked Frozen frying chips as sold Chipped & fried Nd<10boiled <30Nd<10 King Edward potatoes raw Chipped & fried nd<10Boiled <30 LC-MS-MS nd GC-MS <10 Baking potatoes raw SNFA result (µg/kg) Acrylamide concentration (µg/kg) Sample Yield of acrylamide increases substantially with browning

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

Temperature (Kelvin) Acrylamide (ppb) AA Formation at 15 Minutes as a function of Temperature AA = * e (.07930*(Temp-383))

Effect of pH on Acrylamide formation

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

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

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

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

Impact of treating with Asparaginase  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  Supercritical CO2 –removes everything but destroys the product  UV light –no effect at several wavelengths including visible

Insight and recommendations for Next Steps  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, Carcinogens and Anticarcinogens in the Human Diet, ‘A comparison of naturally occurring and synthetic substance. National Academy Press.

Feasibility of reducing levels  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  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)  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  Copies of the presentation and or the original references/presentations can be provided on request to Barbara Petersen