Helmut Guenther

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• Helmut Guenther
• Coffee and Coffee Substitutes

2
Progress in the coffee sector

• Coffee
• summarizing the results of a research program
  which was initiated and conducted by the coffee
  industry with participation of more than 20
  European companies
• Coffee Substitutes with focus on Chicory
• as a key ingredient in coffee substitute products
• and identified to have relatively higher
  acrylamide level

3
I. Natural Parameters

• Chemical/physical parameters of green coffee
  beans
• Green Coffee varieties Robusta vs. Arabica
• Investigations indicate that roasting of Robusta
  green coffees in tendency results in slightly
  higher levels of Acrylamide compared to Arabica
  green coffees.
• Explanation
• Hypothesis is that this is driven by differences
  in chemical/physical properties (e.g. acidity)
  and precursor levels (tendency of higher
  Asparagine levels in Robusta coffees)
• Carbohydrate concentrations have not been found
  to correlate with acrylamide levels in roast
  coffee.
• Quality Impact
• Arabica and Robusta green coffees are distinctly
  different in sensorial properties. Accordingly
  any adaptation of a green coffee blend would have
  a significant impact on the final product quality

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I. Natural Parameters (continued)

• Agronomic Factors
• Narrow range of precursor (Asparagine) levels
  does not provide opportunity of selecting green
  coffees to influence Acrylamide formation
• No studies conducted to date on the impact of
  fertilizers/ climate/ soil on precursors

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II. Product Composition

• Roast Coffee and Soluble Coffee are based to 100
  on green coffee - without any allowed further
  ingredient. No existing option to influence the
  Acrylamide level by replacing ingredients

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III. Process Conditions

• Pilot plant scale investigations in influences of
  coffee roasting conditions on Acrylamide
  formation have covered a broad range of
  technologies and process conditions
  representing the range of typical technologies
  and product qualities across Europe.
• green coffees
• wet processed Arabica (Colombia)
• dry processed Arabica (Brazil)
• dry processed Robusta (Vietnam)
• roast time
• very fast (90 sec) to very slow (16 min)
• degree of roast
• very light to very dark
• Quality Impact
• Green coffee blend, roasting time and degree of
  roast are key design parameter to consistently
  achieve target final product qualities and
  flavour profiles. Modifications of these
  variables in existing products would result in
  significant differences in sensorial properties
  and final product qualities.

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III. Process Conditions (continued)

• Acrylamide formation in coffee is different to
  other food categories. At roasting the Acrylamide
  formation starts rapidly. After reaching a
  maximum the level of Acrylamide decreases with
  continued roasting to a level which is 25 30
  of the maximum level depending on the target
  final degree of roast

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III. Process Conditions (continued)

• Variations of total roast times by modifying
  roasting temperatures did not influence the
  maximum level during roasting
• Maximum levels at lower degrees of roast than
  commercial products

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III. Process Conditions (continued)

• Variations of degree of roast at constant roast
  time show a slight decrease of Acrylamide with
  increasing degree of roast within the range of
  laboratory variability. Consequently it would be
  very difficult to validate any reduction.

• Quality Impact
• Degree of roast is an essential parameter to
  specify the quality
• and flavour leaving only very limited options
  to reduce
• the Acrylamide level

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III. Process Conditions (continued)

• Results of the Pilot Plant program have been
  verified by a set of 50 roast coffee samples
  produced on 16 different commercial roasting
  systems using different green coffee qualities
  and applying different roasting conditions
  representing the state-of-the-art technology of
  the European coffee industry

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IV. Finished Product Characteristics

• Sensorial properties
• The selection of the green bean blend and the
  specification of the process conditions are
  determining the finished product sensorial
  properties. Any variation to achieve a reduction
  of the Acrylamide level would result in
  significant quality changes leaving only very
  limited options for reduction
• Stability of Acrylamide
• Publications indicate that different to other
  food categories- Acrylamide may not be stable in
  packed roast coffee products when storing at room
  temperature during the best-before-period and may
  significantly decrease to 40-60 of the initial
  level. These observations have not yet been
  elucidated.
• Finding may need consideration in data
  evaluations but offers no immediate mitigation
  opportunity as freshness is one of the key coffee
  quality attributes

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Progress in the coffee sector

• Coffee
• summarizing the results of a research program
  which was initiated and conducted by the coffee
  industry with participation of more than 20
  European companies
• Coffee Substitutes with focus on Chicory
• as a key ingredient in coffee substitute products
• and identified to have relatively higher
  acrylamide level

13
I. Natural Parameters

• Agronomic Factors Chicory
• Only minor effects of agronomic factors
• Testing of five Chicory varieties grown under
  same conditions-did not show significant
  differences in Acrylamide content
• Fertilization level has a very limited impact on
  Acrylamide level. Variation is less than 10
  between lowest and highest fertilization level in
  test
• The date of harvest has no significant impact on
  Acrylamide content
• Indication that the initial free Asparagine
  content in the dried Chicory is correlated to the
  Acrylamide formation

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II. Product Composition

• Chicory has shown to be the major contributor to
  Acrylamide in coffee substitutes.

• Quality Impact
• Recipe adjustments in direction of lower
  Acrylamide levels would result in significant
  changes in key quality attributes

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III. Process Conditions

• Investigations in influence of Chicory roasting
  conditions on Acrylamide formation on two
  different roasting systems
• Roast time
• short (45 min) to long (85 min)
• Degree of roast
• very light to dark
• Cutting shape (slices vs. semolina)
• Roast time variation with no effect except at
  very short roast times
• Cutting shape with no effect
• Formation at roasting follows same pattern as in
  coffee

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III. Process Conditions (continued)

• During the initial phase of roasting the
  Acrylamide formation starts rapidly. After
  reaching a maximum the level of Acrylamide
  decreases with continued roasting

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III. Process Conditions (continued)

• Darker roasting slightly reduces the
  Acrylamide content.

• Quality Impact As the roast degree is the main
  parameter to specify the sensorial quality of the
  roasted Chicory there are clear limitations in
  the degree of variations of the roasting

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IV. Finished Product Characteristics

• Sensorial properties
• The selection of the coffee substitutes blend
  and the specification of the process condition
  are determining the finished product sensorial
  properties. Any variation to reduce the
  Acrylamide level would result in significant
  quality changes leaving only marginal options
  for reduction
• Future efforts will need to focus on agronomical
  factors and establish the degree of compositional
  change in the raw material in balance of the
  targeted reduction in Acrylamide with the impact
  on quality and nutritional aspects