The Good the Bad and the Ugly<br />The Impact of Off-flavours and Taints on Product Quality<br />Dr Bill Simpson<br />Cara...
Overview<br /><ul><li>Definitions
Consumer impact
Off-flavours
Taints
Prevention and control</li></ul>overview<br />
Definitions<br />definitions<br />
Not all off-flavours and taints are created equal<br />definitions<br />
Consumer impact<br />“It’s different”<br />“It’s not quite right”<br />“I’m not sure I like this”<br />“There’s something ...
Ecomomicimpact<br />2010<br />One chemical<br />consumer impact<br />2-Methyl napthalene<br />Contaminant from cereal pack...
Flavour thresholds<br />Positive flavours<br />Off-flavours<br />flavour thresholds<br />Taints<br />Log flavour threshold...
Categories of off-flavours and taints<br />Halophenols<br />Sulphur compounds<br />Aldehydes<br />Peptides<br />categories...
Origins of off-flavours<br />origins<br />
Off-flavours produced by microorganisms<br /><ul><li>Diacetyl
Butyric
Dimethyl sulphide
Hydrogen sulphide
Methanethiol
Dimethyl disulphide
Indole
Skatole
Isovaleric
Guaiacol
Styrene
Ethyl acetate
Acetaldehyde
‘Sour’
Acetic
‘Mousy’
‘Mushroom’
1,3-Pentadiene</li></ul>off-flavours<br />
Case study<br /><ul><li>Obnoxious odour in commercial beer – ‘rancid’
Traced to combination of diacetyl and butyric acid – confirmation by GC
The two flavours found to act synergistically to give a flavour intensity which belied their low concentration
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The Good The Bad And The Ugly The Impact Of Off Flavours And Taints On Product Quality

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Leatherhead Food Research 9 – 11 November 2010

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The Good The Bad And The Ugly The Impact Of Off Flavours And Taints On Product Quality

  1. 1. The Good the Bad and the Ugly<br />The Impact of Off-flavours and Taints on Product Quality<br />Dr Bill Simpson<br />Cara Technology Limited<br />www.cara-online.com<br />Introduction to Flavours and their Applications<br />Leatherhead Food Research 9 – 11 November 2010<br />
  2. 2. Overview<br /><ul><li>Definitions
  3. 3. Consumer impact
  4. 4. Off-flavours
  5. 5. Taints
  6. 6. Prevention and control</li></ul>overview<br />
  7. 7. Definitions<br />definitions<br />
  8. 8. Not all off-flavours and taints are created equal<br />definitions<br />
  9. 9. Consumer impact<br />“It’s different”<br />“It’s not quite right”<br />“I’m not sure I like this”<br />“There’s something wrong here”<br />“I’m worried”<br />“Help!”<br />Consumer impact<br />
  10. 10. Ecomomicimpact<br />2010<br />One chemical<br />consumer impact<br />2-Methyl napthalene<br />Contaminant from cereal packaging<br />28 million boxes of cereal recalled<br />
  11. 11. Flavour thresholds<br />Positive flavours<br />Off-flavours<br />flavour thresholds<br />Taints<br />Log flavour threshold<br />
  12. 12. Categories of off-flavours and taints<br />Halophenols<br />Sulphur compounds<br />Aldehydes<br />Peptides<br />categories<br />Haloanisoles<br />Other phenolics<br />Acids<br />Heterocyclic compounds<br />Esters<br />Hydrocarbons<br />Metals<br />Bases<br />
  13. 13. Origins of off-flavours<br />origins<br />
  14. 14. Off-flavours produced by microorganisms<br /><ul><li>Diacetyl
  15. 15. Butyric
  16. 16. Dimethyl sulphide
  17. 17. Hydrogen sulphide
  18. 18. Methanethiol
  19. 19. Dimethyl disulphide
  20. 20. Indole
  21. 21. Skatole
  22. 22. Isovaleric
  23. 23. Guaiacol
  24. 24. Styrene
  25. 25. Ethyl acetate
  26. 26. Acetaldehyde
  27. 27. ‘Sour’
  28. 28. Acetic
  29. 29. ‘Mousy’
  30. 30. ‘Mushroom’
  31. 31. 1,3-Pentadiene</li></ul>off-flavours<br />
  32. 32. Case study<br /><ul><li>Obnoxious odour in commercial beer – ‘rancid’
  33. 33. Traced to combination of diacetyl and butyric acid – confirmation by GC
  34. 34. The two flavours found to act synergistically to give a flavour intensity which belied their low concentration
  35. 35. Butyric acid produced at one stage of the production processed influenced diacetyl concentrations at a later stage – two different microbiological events</li></ul>off-flavours<br />
  36. 36. Case study<br /><ul><li>‘Taint’ in fruit juice – ‘smoky’
  37. 37. Traced to presence of guaiacol – confirmation by GC
  38. 38. Source identified as growth of Alicyclobacillus bacteria
  39. 39. This organism can grow at very low pH values in fruit juice to cause flavour spoilage – can also produce 2,6-dibromophenol and 2,6-dichlorophenol
  40. 40. Organism survives juice pasteurization and grows in supply chain</li></ul>off-flavours<br />
  41. 41. Off-flavours produced by enzymicaction<br /><ul><li>cis-3-Hexenol
  42. 42. cis-3-Hexenal
  43. 43. trans-2-Nonenal
  44. 44. trans-trans-2,4-Heptadienal
  45. 45. ‘Bitter’
  46. 46. ‘Metallic’</li></ul>off-flavours<br />
  47. 47. Off-flavours produced by non-enzymic action<br /><ul><li>Methional
  48. 48. Dimethyl sulphide
  49. 49. Furfural and related compounds
  50. 50. Beta-Damascenone
  51. 51. ‘Burnt’</li></ul>off-flavours<br />
  52. 52. Off-flavours with a complex origin<br /><ul><li>Catty
  53. 53. 2-Furfuryl ethyl ether
  54. 54. 1-Napthol
  55. 55. 3-Methyl-2-butene-1-thiol</li></ul>off-flavours<br />
  56. 56. Case study<br /><ul><li>Unpleasant ‘taint’ in commercial lager – ‘tom cat urine’
  57. 57. Affected almost all beers made in several breweries simultaneously
  58. 58. Traced to specific batches of malt produced after a certain date
  59. 59. Causative agent identified as a sulphur compound – 4-methyl-4-mercapto-pentan-2-one
  60. 60. Source was material derived from paint used in the maltings which reacted with yeast-derived H2S in the brewery</li></ul>off-flavours<br />
  61. 61. Case study<br /><ul><li>Odour in beer exposed to light – ‘skunky’
  62. 62. Predisposing factors identified before causative compound was identified analytically – 3-methyl-2-butene-1-thiol
  63. 63. Extremely odour-active – ng to pg flavour threshold
  64. 64. Long-range UV light cleaves fatty side chain from hop bitter acid – requires vitamin co-factor – side chain reacts with sulphur compound to generate MBT
  65. 65. Modified hop materials eliminate risk</li></ul>off-flavours<br />
  66. 66. Taint ‘vectors’<br /><ul><li>Ingredients
  67. 67. Water
  68. 68. Product water
  69. 69. Process water
  70. 70. Gases
  71. 71. Environmental air
  72. 72. Process gases
  73. 73. Packaging materials
  74. 74. Environment</li></ul>taints<br />
  75. 75. Taints from ingredients<br /><ul><li>2,4,6-Trichloroanisole
  76. 76. 2,4,6-Tribromoanisole
  77. 77. 2,6-Dichlorophenol
  78. 78. 2-Bromophenol
  79. 79. 2-Isobutyl-3-methoxypyrazine
  80. 80. o-Aminoacetophenone
  81. 81. 5-alpha-Androst-16-en-3-one</li></ul>taints<br />
  82. 82. Taints from water<br /><ul><li>Geosmin
  83. 83. 2-Methyl-isoborneol
  84. 84. 2-Isopropyl-3-methoxypyrazine
  85. 85. 2-Isobutyl-3-methoxypyrazine
  86. 86. Methyl tertiary-butyl ether (MTBE)
  87. 87. o-Cresol
  88. 88. trans-trans-2,4-Heptadienal
  89. 89. 2,6-Dichlorophenol
  90. 90. 2-Bromophenol
  91. 91. Trihalomethanes</li></ul>taints<br />
  92. 92. Taints from the environment<br /><ul><li>2,4,6-Trichloroanisole
  93. 93. 2,4,6-Tribromoanisole
  94. 94. 2-Methyl-isoborneol
  95. 95. 2-Isopropyl-3-methoxypyrazine
  96. 96. 2-Isobutyl-3-methoxypyrazine
  97. 97. o-Cresol and cresol derivatives
  98. 98. 2,6-Dichlorophenol and other chlorophenols
  99. 99. 2-Bromophenol and other bromophenols</li></ul>taints<br />
  100. 100. Taints from process gases<br /><ul><li>Hydrogen sulphide
  101. 101. Dimethyl sulphide
  102. 102. Dimethyl disulphide
  103. 103. Dimethyltrisuphide
  104. 104. Methanethiol
  105. 105. Ethanethiol
  106. 106. Acetaldehyde
  107. 107. Various hydrocarbons</li></ul>taints<br />
  108. 108. Case study<br /><ul><li>Odour in soft drinks - ‘chemical’ - first noticed by school children
  109. 109. Caused ‘illness’ and led to mass hospitalizations
  110. 110. Product withdrawn from several European markets
  111. 111. Wiped billions off the Company’s share price
  112. 112. Traced to sulphur compounds, including methanethiol, dimethyl disulphide, dimethyl trisulphide – derived from CO2 gas ingredient
  113. 113. Consumer reaction believed to have been psychosomatic</li></ul>taints<br />
  114. 114. Taints from packaging materials<br /><ul><li>Acetaldehyde
  115. 115. 2,4,6-Trichloroanisole
  116. 116. 2,4,6-Tribromoanisole
  117. 117. ..... and a huge number of compounds derived from inks, plasticizers, glues, lubricants etc
  118. 118. Recycling is a big risk</li></ul>taints<br />
  119. 119. Case study<br /><ul><li>Unusual odour from plastic bread bags – ‘antiseptic’
  120. 120. Analysis revealed many compounds
  121. 121. Sensory work showed that most of the compounds present did not give rise to the type of flavour identified
  122. 122. Selective extraction and GC-MS identified 6-chloro-o-cresol as the cause
  123. 123. The origin of the taint was not established</li></ul>taints<br />
  124. 124. Case study<br /><ul><li>Problem with coffee production in some parts of Brazil – the ‘Rio’ defect
  125. 125. Medicinal, phenolic, iodine-like
  126. 126. Identified by GC-MS as 2,4,6-trichloroanisole, together with its precursor 2,4,6-trichlorophenol
  127. 127. Concentrations of ng/l
  128. 128. Source not yet identified but likely to involve exposure to wood preservatives and the action of moulds on those preservatives</li></ul>taints<br />
  129. 129. Taints from accidental product contamination<br />Whoops!<br /><ul><li>‘Caustic’ / ‘alkaline’
  130. 130. ‘Acidic’ / ‘sour’
  131. 131. 6-Chloro-o-cresol
  132. 132. 6-Chloro-2-methylphenol
  133. 133. 2-Iodophenol
  134. 134. 2,4,6-Trichloroaniline</li></ul>taints<br />
  135. 135. Prevention of problems<br /><ul><li>Screening of raw materials
  136. 136. Screening of in-process samples
  137. 137. Screening of packaging materials
  138. 138. Screening of finished product
  139. 139. Screening of stored product
  140. 140. Screening of product in the market
  141. 141. Screening of the assessors who do the screening</li></ul>prevention<br />
  142. 142. Sensory testing<br />prevention<br />2-Isobutyl-3-methoxypyrazine<br />
  143. 143. Sensory testing<br /><ul><li>Sure-footed identification of off-flavours and taints requires prior exposure and training
  144. 144. Training with reference standards can be used to build up the required skill
  145. 145. In the brewing industry a performance assessment scheme has been operating for almost 10 years - >7,000 assessors in 450 breweries</li></ul>prevention<br />
  146. 146. Process management<br /><ul><li>Understanding of which chemicals give rise to which off-flavours and taints
  147. 147. Understanding of the mechanisms by which such off-flavours and taints arise in the process
  148. 148. Understanding the factors which pre-dispose a production process to problems – implementation of robust preventative measures</li></ul>prevention<br />
  149. 149. Detailed insights<br /><ul><li>Pareto charts help focus actions
  150. 150. Look for patterns of flavour non-conformances to identify root causes</li></ul>prevention<br />% of samples affected<br />
  151. 151. Summary<br /><ul><li>There are hundreds of compounds that can give rise to abnormal product flavour
  152. 152. Off-flavours are generated internally within the product
  153. 153. Taints arise externally and are carried by a vector
  154. 154. Sensory testing is the key defence with analytical techniques helping with identification of root causes
  155. 155. Myriad sources of problems but considerable literature and knowledge on the subject with knowledge of relevance to multiple industries</li></ul>summary<br />
  156. 156. Contact details<br />Cara Technology Limited<br />Leatherhead Enterprise Centre<br />Randalls Road<br />Leatherhead<br />Surrey<br />KT22 7RY<br />UK<br />Tel +44 1372 822218 Fax +44 1372 821599<br />www.cara-online.com bill.simpson@cara-online.com<br />contact<br />

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