Handbook of Vanilla Science and Technology

Sample #19 is a private label of a well-respected supermarket chain and the label states that the product is “Pure Bourbon Vanilla Extract”. Based on common understanding, Bourbon vanilla indicates beans from Madagascar, Reunion, and the Comoros islands, although in some opinions Bourbon denotes the beans of V. planifolia species grown elsewhere. Moreover, the expression “Bourbon” is also used to indicate quality and hence is not relevant for our analysis. This sample is apparently a blend of some Bourbon and Indonesia-grown beans based on organoleptic characteristics.

Sample #12 is a blend of good quality vanilla beans with corn syrup added for flavor enhancement. Sample #42 was obtained from a gourmet retail store and is packaged in an appealing, distinguished bottle that carries a premium price. The label states that it is a double intensity vanilla extract made from vanilla oleoresin, from beans originating from Veracruz, Mexico. There is no requirement to state the origin of the vanilla beans. However, when the name states a place of origin, Mexico for example, the extract should be only from Mexican beans. The exceptionally high level of vanillin, the lack of the other flavor components associated with vanilla extracts (Figure 12.5), and the lack of sediment in the bottle, strongly suggest there is actually no vanilla oleoresin in the product. The organoleptic properties also suggest this product is actually synthetic vanillin.

Sample #61 is an industrial sample of a blend made up from Madagascar- and Indonesia-grown beans. This sample is a good reference for the content and ratio of constituents in a blended vanilla extract.

Sample #65 is 100% Madagascar Bourbon vanilla extract. It is the top of the line and sells in gourmet stores. It is a good reference for comparing against other vanilla extracts.

12.6.3 Total phenol content of the retail vanilla extracts

Total phenol is a non-specific assay to measure the total phenols in an extract. In vanilla extract, total phenol is a good quality indicator and can be related to the strength of the extract or to its fold. According to the standard of identity, vanilla extract must be at least one-fold. If we are certain that the vanilla extract does not contain any added synthetic chemicals, such as synthetic vanillin or ethyl vanillin, the total phenol assay is a very simple way to determine the fold of an extract. Figure 12.6 illustrates the linear relationship of between total phenol and the fold of an extract. A good one-fold vanilla extract usually contains total phenols at 350 to 450 mg chlorogenic acid equivalents mL^-1 vanilla extract. Figure 12.7 shows the total phenol content in the tested samples. The graph shows that most samples contained 350 to 400 mg chlorogenic acid equivalent per 1 mL extract, but samples #11 and 39 contain less than 50 mgmL^-1. This low level of total phenols suggests these vanilla extracts are less than one-fold or were produced from low quality beans. Samples 20, 40, 42, and 46 contain over 800 mgmL^-1. Samples 20 and 42 are likely synthetic based on the high vanillin content. Sample 46 is labeled as imitation vanilla extract. Sample 40 has very low levels of vanillin and the other flavor compounds. The high total phenol content suggests the presence of other compounds, such as ethyl vanillin or coumarin.

Fig. 12.6 Relationship of total phenols to fold of a vanilla extract.

Fig. 12.7 Total phenol analysis in samples 1 to 65.

12.7 CONCLUSION AND RECOMMENDATION

In addition to the analyses presented above, we tasted all the extracts with water and 5% sugar with a group of 10 trained non-professional individuals. The results revealed that vanilla samples labeled as being from the same sources were totally different in the way they were evaluated. When a vanilla extract carries a label “100% Pure Madagascar Bourbon” or “100% Tahitian” we would expect that even when they are coming from different companies, the taste will be similar due to their common origins of the beans. The study indicated that there were no similarities among such retail products. This hints that there is no standardization in the retail business of vanilla extracts.