In the Lab
September 1, 2007
In the Lab
by Rick Brownell
The correlation between vanillin content and vanilla quality
When prices of vanilla beans soared from 2000 to 2004, a simultaneous decline in vanillin content was also a somewhat overlooked cause for concern. Vanillin content is an important indicator of bean quality, which has improved in recent years, but has still not returned to pre-crisis levels.
Vanillin is the most predominant chemical compound in vanilla beans. Typically, the vanillin content before the crisis was 1.70 to 1.85 percent in extraction-grade vanilla beans, as measured by HPLC (AOAC 990.25). An alternate method of analysis, UV Spectrophotometer (AOAC 966.12), may also be used, but is less accurate because it measures other phenolic compounds in addition to vanillin.
During the vanilla crisis, the vanillin content of vanilla beans averaged only 1.20 to 1.30 percent by HPLC. The decline resulted primarily from large quantities of immature beans, which were either sold at discounted prices or blended with mature beans to lower the overall average cost of the lot. The abundance of immature beans resulted from early picking by growers, who feared they would be stolen if left on the vines until full maturity. Since vanillin precursors form primarily during the last few months on the vine, early picked beans are far lower in vanillin content.
Another cause of early picked beans was the cyclones of 2000 and 2004. They blew many beans off the vines, several months before they were ready to be harvested. Too valuable to be left to rot, these beans were gathered and processed, subsequently finding their way into the market as well.
Immature beans have other quality problems besides low vanillin. The flavor profile is inferior because other important flavor components are also under developed. This tends to accentuate the woody, earthy characteristics of extracts made from these beans. Immature beans are also more susceptible to mold, since vanillin is a natural mold inhibitor. While mold can be eradicated in beans themselves, the associated musty flavor remains. Finally, immature beans are often cured and stored by growers unfamiliar with the proper techniques for doing so, resulting in detrimental off-notes.
Today, there are still ample quantities of early picked beans available. But with it being a buyers market, most lots of first-quality extraction grade beans have a vanillin content of 1.40 to 1.60 percent by HPLC. Still not back to pre-crisis levels, but a significant improvement from just a few years ago.
Looking ahead, it is important that food and beverage companies recognize the relationship between vanillin content and quality in vanilla beans and extracts. They should request that extract suppliers include vanillin content by HPLC in product specifications and provide certificates of analysis (COA’s) with each lot. Lower-priced extracts are more often than not made from lower-quality beans.
Vanillin content provides an easy and effective guide for evaluating and ensuring the quality and consistency of vanilla beans and extracts.
Rick Brownell is vice president of vanilla products for Brooklyn, N.Y.-based Virginia Dare.$OMN_arttitle="In the Lab";?> $OMN_artauthor="Rick Brownell";?>