Fermentation to Produce Flavoring Materials

As can be seen in Table 9.5, nutrient source had a strong influence on the production of the methoxy pyrazines by a selected mutant of Pseudomonas perolens. The end result is that an organism that initially produced a few ppb of the methoxy alkyl pyrazines was converted into an organism that produced ppm levels of the target compounds. While one may not think that ppm levels of an aroma compound is significant, these pyrazines have sensory thresholds in the pptr levels. 

Similar approaches (UV irradiation) have been used to enhance the yield of diacetyl in the production of starter distillates [82]. This method yielded cultures that produced a 4.5-fold increase in total acetoin + diacetyl production. Starter distillates are very broadly used in the reproduction of dairy flavors. 

The Production of Selected Methoxy Alkyl Pyrazines by Selected P. perolens Mutant on Different Growth Media 

Source From Mclver, R.C., Ph.D. thesis, University of Minnesota, St. Paul, 1986. With permission. 

FIGURE 9.11 The conversion of ricinoleic acid to y-decalactone by Yarrowia lipolytica. (From Farbood, M., B.J. Willis, Production of y-Decalactone, U.S. Patent 4560656, 1985. With permission.) 

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