Furan: Mechanisms of Formation and Levels in Food

Document Sample
Furan: Mechanisms of Formation and Levels in Food Powered By Docstoc
					 Furan: Mechanisms of Formation
        and Levels in Food

Don S. Forsyth, Adam Becalski, Valerie Casey, Steve
Seaman,Karen Pepper and Samuel Ben Rejeb, Food
Research Division, Bureau of Chemical Safety, Food
Directorate, Health Canada




  Health   Santé
  Canada   Canada
                   Background
• Late March, 2004- Health Canada informed of US
  FDA investigation of furan in canned and bottled
  food commodities
• Furan has been shown to be carcinogenic in mice
  and rats, classified as “possibly carcinogenic to
  humans” (Group 2B) by IARC in 1995
• Although furan is used in industrial processes the
  likely source was considered to be formation
  during food processing
• April, 2004- Health Canada commenced method
  development for study of mechanism(s) of
  formation and survey of Canadian food products
 Health   Santé
 Canada   Canada
                   Furans in Foods
• Furan derivatives have been reported in a
  wide variety of foods and are a significant
  flavour and odour component in coffee,
  cocoa, and various cooked meat products

• Furan has been found in coffee, canned
  beef, sodium caseinate, soy and rapeseed
  protein and caramel

 Health   Santé
 Canada   Canada
          Possible Mechanisms of
                Formation
• Thermal degradation of carbohydrates
  (Maillard reaction)

• Thermal oxidation of lipid

• Decomposition of ascorbic acid or its
  derivatives


 Health   Santé
 Canada   Canada
Effect of Canned Beef Formulation and Processing Time
    on Furan Levels (Persson and von Sydow 1974)
                                                  Processing Time   Furan
                Formulation                        (min at 121°C)   (ng/g)
79.3% beef, 20% H2O, 0.7% NaCl                           15          930
                                                         30          750
                                                         45          760
                                                         60          960
                                                         75          870
66.3% beef, 13% fat, 20% H2O, 0.7% NaCl                  30         3700
74.3% beef, 5% carbohydrate, 20% H2O, 0.7% NaCl          30          670
61.3% beef, 13% fat, 5% carbohydrate, 20% H2O,
                                                         15         2800
0.7% NaCl
                                                         30         3900
                                                         45         3700
                                                         60          980
      Health   Santé
      Canada   Canada                                    75         1400
                   Analytical Methods
Two methods were used:

1. Static Headspace Analysis
   – Mechanism(s) of formation and food survey


2. MicroExtraction Technique (MET)- A SPME
   related method developed at Health Canada
   – Food survey


Both methods are based on isotope dilution (d4-
   furan) gas chromatography-mass spectrometry
 Health   Santé
 Canada   Canada
Mechanism of Formation Studies

• 10 mg of test compound was added to a
  1.5 mL vial containing 0.5 mL water
• Vials were heated 30 min at 118 ± 1°C
• Cooled to 4°C
• D4-furan added




 Health   Santé
 Canada   Canada
    Formation of furan from ascorbic acid and
                   derivatives
              Reagents                 Furan (ng/g)a                      SD
Ascorbic acid                                     35                     11.9
Ascorbic acid + Fe+3                              38                      9.6
Sodium ascorbate                                 3.4                      0.7
Sodium ascorbate + Fe+3                           29                      8.5
Dehydroascorbic acid                             338                     44.5
Dehydroascorbic acid + Fe+3                      381                       99
Isoascorbic acid                                 379                      101
Sodium isoascorbate                               15                      0.8
Sodium isoascorbate + Fe+3                       144                      3.7
Ascorbyl palmitate                               6.8                      0.7
Ascorbyl palmitate + Fe+3                        4.3                      0.4
                              aConcentration of furan in 0.5 mL of reaction mixture
                              Reagent – 10 mg
  Health   Santé
                              Fe+3 – 100 µg
  Canada   Canada             Each value is an average of 4 experiments
        Formation of furan from fatty acids

        Reagents      Furan (ng/g)a                Nb           SD
Linoleic                      125                   4           26
Linoleic + Fe+3               498                   4          185
Linolenic                     625                   4           96
Linolenic + Fe+3              985                   3            2
Trilinoleate                   78                   4           16
Trilinoleate + Fe+3           136                   4           20
Trilinolenate                 570                   4           96
Trilinolenate +Fe+3           463                   4            4
                      aConcentration of furan in 0.5 mL of reaction mixture
                      Reagent – 10 mg
                      Fe+3 – 100 µg
                      b number of experiments
   Health   Santé
   Canada   Canada
  Chromatograms of: a) linolenic acid reaction and
  b) furan standard (1 ppm native, 0.25 ppm d4)
    a
 bnac
Au d ne                                                                         bnac
                                                                               A udne

                                     IC 521.
                                    T :1 0 0 6D
   150
    600                                                                                                            4    :       D
                                                                                                          c n 0 ( . 2 in 5 2 1 . -
                                                                                                         S a 1 5 8 6 m ) 1 0 0 6 ()
                                                                                                                                      68
   100
    600                                                                                80
                                                                                      100

    500
   150
                                                                                       60
                                                                                      100
    500
   100

   150
    400                                                                                40
                                                                                      100           39

    400
   100                                                                                 20
                                                                                      100
    300
   150
                                                                                       00
                                                                                      100
    300
   100

   150
    200                                                                                00
                                                                                      80

    200
   100
                                                                                       00
                                                                                      60
    100
   150

   100
    100
                                                                                       00
                                                                                      40

    000
   150                                                                                 00
                                                                                      20       37
   100
    000                                                                                      34      42       0 23 5
                                                                                                             5 55 5           67
                                                                                                    41                    63
                                                                                        0
            8 0 . 5 . 0 . 5 . 0 . 5 . 0 . 5 . 0 . 5 . 0 . 5 . 0
             .2 82 8 3 8 3 8 4 8 4 8 5 8 5 8 6 8 6 8 7 8 7 8 8                           3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 6 6 6 6 6 7
                                                                                          0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0
 im-
T e>
   -                                                                             z
                                                                                / -
                                                                               m ->




    b
Ab n a ce
  u d n                                                                         u
                                                                               b dne
                                                                               A nac
                                    T      0 0 1
                                     IC: A0 1 0 .D

   1 5 0
    9 0 0                                                                                                 a      4    : 0
                                                                                                         c 148 3 in 0 01 -  D
                                                                                                         S n 0 ( . 5 m) A 10. ()
                                                                                       50
                                                                                      300
   1 0 0
    9 0 0                                                                                                                             8
                                                                                                                                      6
    8 0 0
   1 5 0

   1 0 0
    8 0 0                                                                              00
                                                                                      300
    7 0 0
   1 5 0
                                                                                                    9
                                                                                                    3
    7 0 0
   1 0 0
                                                                                       50
                                                                                      200
    6 0 0
   1 5 0

    6 0 0
   1 0 0

   1 5 0
    5 0 0                                                                              00
                                                                                      200
    5 0 0
   1 0 0

    4 0 0
   1 5 0
                                                                                       50
                                                                                      100
    4 0 0
   1 0 0

    3 0 0
   1 5 0

   1 0 0
    3 0 0                                                                              00
                                                                                      100
    2 0 0
   1 5 0

    2 0 0
   1 0 0
                                                                                       00
                                                                                      50
   1 5 0
    1 0 0                                                                                       7
                                                                                                3
    1 0 0
   1 0 0
                                                                                             3
                                                                                             4     4
                                                                                                   2 4
                                                                                                     5  4 5 5 5
                                                                                                        9 1 3 5   6 66
                                                                                                                  2 45  0
                                                                                                                        7
   1 5 0
    0 0 0                                                                               0
                                                                                          03 43 84 24 64 05 45 86 26 66 0
                                                                                         3 23 63 04 44 85 25 65 06 46 87
            8.20 8.25 8.30 8.35 8.40 8.45 8.50 8.55 8.60 8.65 8.70 8.75 8.80
Tim - >
   e -                                                                          z
                                                                                / -
                                                                               m->



     Health        Santé
     Canada        Canada
                   Conclusions
   Two pathways of furan formation were
   identified in the model systems:

1. Polyunsaturated fatty acids (linoleic,
   linolenic) via peroxidation and ring
   closure
2. Decomposition of ascorbic acid
   derivatives particularly dehydroascorbic
   acid and isoascorbic acid

 Health   Santé
 Canada   Canada
  Preliminary Survey Results




Health   Santé
Canada   Canada
            Furan in Baby Foods
                        Furan Concentration (ng/g)
            Sample
                          METa      Headspacea
Beef with Broth             6             6
Banana                     7                    8
Carrot                     54                   56
Vegetable and Chicken      18                   19
Apple Sauce                 5                    5
Mixed Vegetable            146                  154
Alphabet Beef               62                   66
Beef Stroganoff            98                   103
Chicken and Stars          25                   26
                              aAverage   of two determinations
 Health   Santé
 Canada   Canada
             Furan in Adult Foods
                       Furan Concentration (ng/g)
            Sample
                          METa            Headspacea
Soups                    35-117               34-117
Chili                    152-227             157-236
Stew                       82                   83
Bean products              14                   14
Canned luncheon meat      7-31                 4-28
Coffee, fresh brewed
                          14-52               14-51

                             aAverage   of two determinations
  Health   Santé
  Canada   Canada
                   Next Steps?
• Further studies on mechanism(s) of
  formation using model systems and
  precursor fortified food matrices
• Losses of furan during food processing
  and cooking
• Further surveys of canned and bottled
  products
• Participate in round robin method
  validation study
• Update health risk assessment as new
  data becomes available
 Health   Santé
 Canada   Canada
                  Thank-you !




Health   Santé
Canada   Canada

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:52
posted:2/19/2012
language:English
pages:16