TABLE 4

Volatiles identified using GC-MS in conched chocolate made from spontaneous and inoculated cocoa pulp fermentationsa

Volatile by stageSensorial descriptor(s) (references)Concn (μg/kg)
Robust parentsAromatic parentsHybridsP. kluyveri Y274Cyb. fabianii Y689S
Y115Y927H28Y184Y397H40H42H57
Fermentation
    Aldehydes
        2-MethylbutanalChocolate (61), malty (62)37.838.319.214.63.919.415.011.312.313.18.4
        2-Phenyl-2-butenalRoasted (61), rum (61), cocoa (61), sweet (61)22.911.210.06.18.25.16.54.15.97.32.1
        3-MethylbutanalChocolate (61), malty (57, 62)127.8132.158.954.315.963.858.045.045.949.928.9
        5-Methyl-2-phenyl-2-hexenalRoasted cocoa (63), sweet (63)12.64.14.21.72.12.33.31.03.02.21.3
        BenzaldehydeAlmond (64)37.041.730.131.512.138.730.427.022.117.011.7
        PhenylacetaldehydeFloral (61), honey (57, 61, 62)53.536.617.511.48.619.420.211.715.318.44.9
    Alcohols
        2-Methyl-1-butanol0.13.70.83.71.22.32.02.31.20.80.2
        2-PhenylethanolFloral (61, 62)142.0122.967.673.262.878.170.776.460.340.230.6
        Isoamyl alcoholMalty (25), bitter (25), chocolate (25)0.127.17.016.32.717.45.411.610.94.61.2
    Esters
        2-Heptyl acetate1.73.21.31.41.87.65.08.72.31.91.5
        Ethyl acetateSolvent (64), fruity (17)2.03.73.428.91.49.15.37.711.53.31.8
        Ethyl decanoatePear (58), grape (58), brandy (58), floral (65)3.43.71.40.90.62.21.83.61.40.90.6
        Ethyl dodecanoateFruity (58), floral (58)7.13.13.11.51.42.23.22.74.01.41.6
        Ethyl hexanoateApple (64), fruity (57), banana (57)0.10.10.12.40.12.50.12.40.10.11.5
        Ethyl octanoateApple (64), fruity (57), pineapple (57)7.519.15.015.87.39.214.78.84.54.42.5
        Ethyl phenylacetateSweet (57), waxy (57)3.01.91.62.00.91.22.21.81.11.01.0
        Isoamyl acetateBanana (64), fruity (17), pear (17)2.45.511.96.82.412.45.16.65.52.77.2
        Methyl acetate17.713.733.035.716.630.025.742.620.320.114.1
        Phenylethyl acetateFloral (62), fruity (57), sweet (57)30.329.516.737.127.215.621.122.916.813.212.3
    Ketones
        1-Hydroxy-2-propanone26.723.08.36.35.48.113.28.46.19.62.2
        2-Butanone5.15.34.33.31.13.23.02.01.92.01.8
        2-Heptanone1.51.92.52.41.15.22.34.04.31.42.9
        2-NonanoneFloral (66), fatty (66)9.515.66.36.35.122.413.133.515.67.64.2
        AcetoinButtery (67), cream (67)278.7276.5106.0147.552.3252.8238.9258.3505.2260.755.5
        DiacetylButtery (57, 61)78.170.464.758.625.375.978.061.4124.450.548.7
    Sulfides
        Dimethyl disulfideCabbage (66)1.00.90.90.90.40.61.00.60.60.40.6
    Volatile acids
        2-Methylbutanoic acidSweaty (57, 62)0.148.135.019.70.116.722.118.711.017.45.8
        Acetic acidSour (57, 62)2,555.72,489.61,087.51,984.2734.01,711.02,907.22,303.51,818.91,983.9279.7
        Butanoic acidSweat (62), buttery (57), rancid (57)2,555.710.03.44.81.34.410.17.76.16.10.3
        Isobutyric acidSweaty (57, 62)26.948.820.136.67.725.747.444.345.441.63.8
        Isovaleric acidSweaty (57, 62)0.1173.144.762.50.151.4102.264.548.474.515.8
        Propanoic acidRancid (25)24.024.812.918.88.817.728.325.815.619.38.2
Roasting
    1-(2-Furanyl)ethanoneSweet (57), balsamic (57), cocoa (57)1.32.11.60.81.01.21.30.91.40.91.5
    2,3,5-Trimethyl-6-ethylpyrazineCandy (67), sweet (67)16.113.88.24.56.710.413.820.27.910.16.0
    2,3-DimethylpyrazineCaramel (58), cocoa (58), hazelnut (61)6.56.52.93.01.33.94.63.12.63.11.2
    2,5-DimethylpyrazineCocoa (58), roasted nuts (58)2.62.41.71.91.31.61.40.91.11.31.0
    2,6-DimethylpyrazineNutty (58), coffee (58), green (58)5.44.71.80.90.61.72.30.90.81.60.8
    2-AcetylpyrroleBread (58), walnut (58), licorice (58)91.642.423.88.024.917.443.211.613.825.910.2
    2-Ethyl-3,5-dimethylpyrazineEarthy (62), potato-chip (57, 62)17.510.74.91.94.93.67.83.82.55.53.6
    2-Methyltetrahydro-3-furanone8.64.93.31.30.81.33.11.10.91.81.5
    MethylpyrazineGreen (61), hazelnut (61), cocoa (58), roasted nuts (58)5.43.82.21.40.82.82.81.31.30.80.4
    TetramethylpyrazineCocoa (58, 61), mocha (61), milk coffee (58, 61)212.9247.7123.186.186.7198.5336.1288.4198.2316.7396.9
    TrimethylpyrazineEarthy (57, 62), cocoa (58, 61), roasted (61), green (61)30.129.213.07.28.115.526.814.09.319.515.2
  • a Two spontaneous (S) and 20 inoculated fermentations were performed, with 10 yeast strains tested in duplicate. The cocoa liquors of the fermentation duplicates were pooled prior to being processed into chocolate (see Materials and Methods for details). 2-Pentyl acetate, ethyl 2-methylbutanoate, ethyl isobutyrate, ethyl isovalerate, ethyl lactate, ethyl propanoate, isobutyl acetate, methyl lactate, and propyl acetate were detected in the cocoa liquors but not in the chocolates.