Concentration Effect on Odor Addition or Synergism in Mixtures of Methyl Sulfide and Tomato Juice

SUMMARY: The effect of various concentrations of tomato juice and methyl sulfide (Me 2 S) in triple distilled water on threshold values of the juice‐Me 2 S mixtures was studied on juices prepared from five varieties of canning tomatoes. When Me 2 S and tomato juice were diluted to less than 10 ppb and 1,000 ppm respectively, before mixing, no significant interaction between juice and Me 2 S was observed in the juice‐Me 2 S mixture. The odor intensities of the two components (as measured by threshold values in distilled water) were additive at subthreshold concentrations. As the concentrations of juice and Me 2 S were increased before mixing, an increasing degree of interaction or synergism was observed in the mixture. At concentrations of 10 5 ppm juice and 1 ppm Me 2 S odor intensity of the mixture was approximately double that which would be expected on an additive basis. However, this may not be a case of true synergism if the concentrations which give rise to the effect produce other products of lower threshold values.