Use of asparaginase to mitigate acrylamide formation in food

Katie Maloney, Ph.D.Novozymes

BIO World CongressMay 2014

Outline

• Background

• What is acrylamide?• Why is acrylamide in food a concern?• How can asparaginase help?

• Applications

• French fries• Dough-based snacks• Crackers and cookies• Breakfast cereals• Coffee

• Summary and conclusions

What is acrylamide?

• Acrylamide is a compound formed naturally during the preparation of foods.• Major pathway involves reaction between asparagine and reducing sugar at

temperatures in excess of 120°C (250°F) and low moisture.

Measured acrylamide content (ppb) in different food categories. Legends shown: Median, 1st quartile, and 3rd quartile. Source: www.irmm.jrc.be/html/activities/acrylamide

Why is acrylamide in food a concern?

Acrylamide has been shown to be carcinogenic in animal studies.

US FDA National Toxicology Program (NTP): final report on the toxicology and

carcinogenicity of acrylamide showing “clear evidence of carcinogenic activity

in animals.” (August 2012)

Research into a possible carcinogenic link for humans has so far been inconclusive.

Risk assessments indicate a human health concern for acrylamide in food.

Acrylamide has been classified by the International Agency for Research on Cancer

(IARC) as “probably carcinogenic for humans.” (1994)

A 3-year EU study of acrylamide (The HEATOX Project) concluded that ”Increasing

toxicological evidence suggests that acrylamide in food might be a cancer

risk factor.” (November 2007)

The Joint FAO/WHO Expert Committee on Food Additives (JECFA) reconfirmed that

levels of dietary exposure to acrylamide indicate a “human health concern.”

(FAO/WHO/February 2010)

How can asparaginase help?

• Acrylamide is mainly formed in food as part of the Maillard reaction.

• The Maillard reaction is also responsible for the desirable flavor, aroma, and color compounds in baked, roasted, and fried foods.

• By converting asparagine into aspartic acid, asparaginase can effectively reduce the level of acrylamide without changing the taste and appearance of the end product.

Asparagine Reducingsugar Heat

Flavor, aroma, andcolor compoundsAcrylamide

Simplified Maillard reaction

asparagine

NH2 NH2

HOOC O

NH2 OH

HOOC O

aspartic acid

H2O

NH3

Asparaginase reaction

+

+ +

Factors to consider when choosing an asparaginase

020406080

100

30 40 50 60 70 80 90 100

Rel

ativ

e A

ctiv

ity (%

)

Temperature (°C)

020406080

100

3 4 5 6 7 8 9 10

Rel

ativ

e A

ctiv

ity (%

)

pH

Acrylaway HighT®Acrylaway®

pHTemperature Reaction time

020406080

100

0 2 4 6 8 10 12

Rel

ativ

e A

ctiv

ity (%

)

pH

020406080

100

0 20 40 60 80

Rel

ativ

e A

ctiv

ity (%

)

Temperature (°C)

Moisture

Acrylaway® for French fries

Peeling and cutting

Blanching

Dipping in SAPP* and glucose

Drying

Par-frying

Freezing

Acrylaway® addition

Add enzyme to SAPP and glucose dip

OR

Apply enzyme as a separate coating just

before drying

*SAPP: Sodium Acid PyroPhosphate

0200400600800

10001200140016001800

Control Treated

Acr

ylam

ide

(ppb

)

Acrylamide mitigation in French fries

• Up to 64% reduction in acrylamide content in French fries

64% reduction

• 6x6 mm cut size• Blanching: 79°C, 23 min• 20,000 ASNU/L Acrylaway dosage• Drying: 60°C, 9 min• Par-frying: 190°C, 45 sec• Final frying: 175°C, 2 min

0

100

200

300

400

500

600

Control TreatedAcr

ylam

ide

(ppb

)

57% reduction

• 7x7 mm cut size• Blanching: 72-78°C, 6-7 min• 30,000 ASNU/L Acrylaway dosage• Drying: 3 zones (70-60-40°C) for 9 min• Par-frying: 153°C, 1-2 min• Final frying: 175°C, 1.5 min

Enzyme added to dip tank Enzyme applied as coating

Acrylamide mitigation in dough-based snacks

• Up to 60% asparagine hydrolysis in snack pellet dough• Up to 95% reduction in acrylamide content in final snack

0

200

400

600

800

0 1000 3500 5500 7000

mg/

100

g d

ry m

atte

r

Enzyme dose (ASNU/kg dry matter)

Asparagine Aspartic acid

0

400

800

1200

1600

2000

2400

0 1000 3500 5500 7000Acr

ylam

ide

(pp

b)Enzyme dose (ASNU/kg dry matter)

• Enzyme added during mixing• Mixing: ~35°C, 15 min• Moisture: 35%• Frying: 185-190°C, 21 sec

Acrylamide mitigation in crackers and cookies

• Up to 87% reduction in acrylamide content in crackers and cookies

0

200

400

600

800

1000

1200

0 500 1000

Acr

ylam

ide

(ppb

)

ASNU/kg flour

0100200300400500600700

13 15 17Acr

ylam

ide

(ppb

)Dough moisture (%)

Control Treated

Graham crackers Ginger nut cookies

• Enzyme added during mixing• Added water: 12.5%

• Enzyme added during mixing• 1000 ASNU/kg flour

Acrylamide mitigation in coffee

• 32-64% reduction in acrylamide content in various types of coffee

0200400600800

1000120014001600

UnwashedArabica A

UnwashedArabica B

UnwashedArabica C

Robusta-Arabicablend

Acr

ylam

ide

(ppb

)

Control Treated

63% reduction

32% reduction

64% reduction

62% reduction

• Added water: ~50% based on weight of green beans• Soaking: 55-60°C, 60-90 min

Acrylamide mitigation in breakfast cereals

• Up to 75% reduction in acrylamide content in breakfast cereals

050

100150200250300350400450500

0 1500 3000

Acr

ylam

ide

(ppb

)

TASU/kg flour

39%reduction 54%

reduction

Batch cooked wheat flakes

• Enzyme added during cooking• Cooking: 104-105°C, 25 min• Moisture content: 33%• Toasting: 230-245°C

0

100

200

300

400

500

600

700

800

900

0 3000

Acr

ylam

ide

(ppb

)TASU/kg flour

75% reduction

• Enzyme added during pre-conditioning• Pre-conditioning: 90-100°C, 10-12 min• Moisture content: 27%• Extrusion: 100-140°C

Whole wheat and bran extruded flakes

Summary and conclusions

• Asparaginases can be used to mitigate acrylamide formation in many different foods

• The benefits of using asparaginase for acrylamide mitigation are related to food safety and brand protection

• Acrylaway® is currently being used in industrial scale to mitigate acrylamide formation in food