Handbook of Vanilla Science and Technology

9.3.1.8 Vanilla tincture for perfumery

This is prepared by macerating vanilla beans with specially denatured alcohol. The finished tincture contains 90% alcohol and is soluble in perfume oils.

9.3.2 Vanilla extract quality parameters

Quality of a vanilla extract can be judged using following parameters:

9.3.2.1 Appearance: color and clarity

Pure single-fold vanilla extract is a pale to dark amber brown clear liquid. Some vanillas have a reddish hue. The color depends on the quality of beans, extraction method used and, to some extent, on the geographic origin of the beans. Clarity of the extract is related to the resin and wax content of the beans. Usually beans with higher resin contents produce cloudier products. Clarity of the product can be achieved through optimization of extraction methods.

9.3.2.2 Flavor

Flavor quality of vanilla extract depends, to a large extent, on the vanilla beans and the extraction method used for its manufacture. In turn, the flavor quality of beans depends on vanilla genotype, geographic region, environment (climate, soil, etc.), harvest maturity of beans, and overall curing technique. Freshly percolated vanilla extract has a slightly harsh alcohol bite, unless tempered with the addition of sugar syrup or glycerin. The product mellows as it ages in a tank over a period of time. Stored under proper conditions (60-65°F) and away from light, vanilla develops pleasant, sweet, somewhat complex and mellow notes.

The following terminology is commonly used to describe vanilla flavor:

Hoffman et al. (2005) have combined gas chromatography, high pressure liquid chromatography, and sensory testing methods in their quest to distinguish “good” vanilla extracts from low quality vanilla extracts. They report that esters of ethyl acetate, ethyl hexanoate, and ethyl octanoate as having pleasant fruity aromas and are very effective at very low concentrations. Acetaldehyde ethyl acetal was associated with a nutty aroma, whereas ethyl nonanoate aroma was similar to cognac and reminiscent of rummy resinous notes in good quality vanilla. Guaiacol, vanillic acid, and p-hydroxybenzoic acid contribute to a smoky odor and faintly phenolic taste. Vanillyl ethyl ether and 4-(ethoxy methyl) phenol are described as having sweet vanilla-like flavors, with creamy coconut undertones.

9.3.2.3 Soluble solids content

Typical single-fold vanilla extract made without any additives has soluble solids content of about 1.8 to 2.2% on the weight basis. Soluble solids are composed of sugars, non-sugar carbohydrates, amino acids and proteins, phenolic compounds, and minerals. Lower values for soluble solids in extracts can arise from incomplete extraction of beans or use of lower than required amount of beans.

9.3.2.4 Vanillin content

This principal flavoring component of vanilla is present in the single-fold extract at levels ranging from 0.2 g per 100 mL (0.2%) for a good quality extract to less than 0.02 g per 100 mL (0.02%) for inferior quality product. Vanillin content of an extract depends on the quality of beans used. Higher quality and higher grade beans produce extracts with higher vanillin content and vice versa. It should be remembered that high vanillin is not the only defining character of high quality of vanilla extract. Vanilla extracts made from Indian vanilla beans tend to yield vanillin content in the range of 0.2 to 0.25% per fold, although Gassenmeier et al. (2008) have found lower values for the 2006/2007 crop of Indian beans. In the last few years, beans from Madagascar have declined in their quality consistency and are averaging less than 0.18% vanillin content per fold. It is generally observed that Indonesian and PNG (Papua New Guinea) bean-based extracts are less consistent in their vanillin content and average less than 0.14%. Besides, a number of blended vanilla products are available, where vanillin content varies from 0.075% to 0.15%. Routinely, vanillin content of vanilla extract is determined using either the UV method (AOAC) or a high-performance liquid chromatography (HPLC) method (Guarino and Brown 1985; Ranadive 1993; Wallace 1983). Vanillin content of vanilla extracts is determined using the procedures described in earlier sections. Of the two methods used, UV (spectrophotometric) and HPLC, the latter gives more accurate but typically 5 to 8% lower values than the values obtained using UV method. Gas chromatography techniques have also been used for vanillin determination.

9.3.2.5 Organic acids - (Wichmann) Lead Number