Vanilla
| Infobox on Vanilla | |
|---|---|
| Example of Vanilla |  |
| Facts | |
| Origin | See text |
| Stowage factor (in m3/t) | 1,91/2,04 m3/t (cases) |
| Humidity / moisture |
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| Ventilation | See text |
| Risk factors | See text |
Vanilla
Contents
Description
Vanilla is a flavour derived from orchids of the genus Vanilla, primarily from the Mexican species, flat-leaved vanilla (V. planifolia). The word vanilla, derived from the diminutive of the Spanish word vaina (vaina itself meaning sheath or pod), simply translates as little pod.
Three major cultivars of vanilla currently are grown globally. The various subspecies are Vanilla planifolia (syn. V. fragrans), grown on Madagascar, Réunion, and other tropical areas along the Indian Ocean; V. tahitensis, grown in the South Pacific; and V. pompona, found in the West Indies, and Central and South America. The majority of the world's vanilla is the V. planifolia variety, more commonly known as Bourbon vanilla (after the former name of Réunion, Île Bourbon) or Madagascar vanilla, which is produced in Madagascar and neighbouring islands in the southwestern Indian Ocean, and in Indonesia. Leptotes bicolor is used in the same way in South America.
Vanilla is the second most expensive spice after saffron, because growing the vanilla seed pods is labour-intensive. Despite the expense, vanilla is highly valued for its flavour. As a result, vanilla is widely used in both commercial and domestic baking, perfume manufacture and aromatherapy.
Stages of production
Harvest
The vanilla fruit grows quickly on the vine, but is not ready for harvest until maturity—approximately six months. Harvesting vanilla fruits is as labour-intensive as pollinating the blossoms. Immature dark green pods are not harvested. Pale yellow discoloration that commences at the distal end of the fruits is an indication of the maturity of pods. Each fruit ripens on its own time, requiring a daily harvest. To ensure the finest flavour from every fruit, each individual pod must be picked by hand just as it begins to split on the end. Overmatured fruits are likely to split, causing a reduction in market value. Its commercial value is fixed, based on the length and appearance of the pod.
If the fruit is more than 15 cm in length, it belongs to a first-quality product. The largest fruits, greater than 16 cm and up to as much as 21 cm, are usually reserved for the gourmet vanilla market, for sale to top chefs and restaurants. If the fruits are between 10 and 15 cm long, pods are under the second-quality category, and fruits less than 10 cm in length are under the third-quality category. Each fruit contains thousands of tiny black vanilla seeds. Vanilla fruit yield depends on the care and management given to the hanging and fruiting vines. Any practice directed to stimulate aerial root production has a direct effect on vine productivity. A five-year-old vine can produce between 1.5 and 3 kg pods, and this production can increase up to 6 kg after a few years. The harvested green fruit can be commercialized as such or cured to get a better market price.
Curing
Several methods exist in the market for curing vanilla; nevertheless, all of them consist of four basic steps: killing, sweating, slow-drying, and conditioning of the beans.
Killing
The vegetative tissue of the vanilla pod is killed to stop the vegetative growth of the pods and disrupt the cells and tissue of the fruits, which initiates enzymatic reactions responsible for the aroma. The method of killing varies, but may be accomplished by heating in hot water, freezing, or scratching, or killing by heating in an oven or exposing the beans to direct sunlight. The different methods give different profiles of enzymatic activity.
Testing has shown mechanical disruption of fruit tissues can cause curing processes, including the degeneration of glucovanillin to vanillin, so the reasoning goes that disrupting the tissues and cells of the fruit allow enzymes and enzyme substrates to interact.
Hot-water killing may consist of dipping the pods in hot water (63–65 °C) for three minutes, or at 80 °C) for 10 seconds. In scratch killing, fruits are scratched along their length. Frozen or quick-frozen fruits must be thawed again for the subsequent sweating stage. Tied in bundles and rolled in blankets, fruits may be placed in an oven at 60 °C for 36 to 48 hours.
Sweating
Sweating is a hydrolytic and oxidative process. Traditionally, it consists of keeping fruits, for seven to 10 days, densely stacked and insulated in wool or other cloth. This retains a temperature of 45–65 °C and high humidity. Daily exposure to the sun may also be used, or dipping the fruits in hot water. The fruits are brown and have attained much of the characteristic vanilla flavour and aroma by the end of this process, but still retain a 60-70% moisture content by weight.
Drying
Reduction of the beans to 25–30% moisture by weight, to prevent rotting and to lock the aroma in the pods, is always achieved by some exposure of the beans to air, and usually (and traditionally) intermittent shade and sunlight. Fruits may be laid out in the sun during the mornings and returned to their boxes in the afternoons, or spread on a wooden rack in a room for three to four weeks, sometimes with periods of sun exposure. Drying is the most problematic of the curing stages; unevenness in the drying process can lead to the loss of vanillin content of some fruits by the time the others are cured.
Conditioning
Conditioning is performed by storing the pods for five to six months in closed boxes, where the fragrance develops. The processed fruits are sorted, graded, bundled, and wrapped in paraffin paper and preserved for the development of desired bean qualities, especially flavour and aroma. The cured vanilla fruits contain an average of 2.5% vanillin.
Grading
Once fully cured, the vanilla fruits are sorted by quality and graded. In general, vanilla fruit grade is based on the length, appearance (colour, sheen, presence of any splits, presence of blemishes), and moisture content of the fruit. Whole, dark, plump and oily pods that are visually attractive, with no blemishes, and that have a higher moisture content are graded most highly. Such pods are particularly prized by chefs for their appearance and can be featured in gourmet dishes. Beans that show localized signs of disease or other physical defects are cut to remove the blemishes; the shorter fragments left are called “cuts” and are assigned lower grades, as are fruits with lower moisture contents. Lower-grade fruits tend to be favoured for uses in which the appearance is not as important, such as in the production of vanilla flavouring extract and in the fragrance industry.
Higher-grade fruits command higher prices in the market. However, because grade is so dependent on visual appearance and moisture content, fruits with the highest grade do not necessarily contain the highest concentration of characteristic flavour molecules such as vanillin, and are not necessarily the most flavourful.
Application
Vanilla is one of the best known flavourings and is used in cooking, in the food industry, in patisserie products and for the production of confectionery, desserts, chocolate, ice cream, liqueurs and perfumes.
Shipment / Storage / Risk factors
A white covering of vanillin crystals is often visible and misidentified as mould, giving rise to claims for mould damage.
One method of transporting vanilla is in bundles in tinplate cans lined with waxed paper, which are in turn packaged per six in wooden boxes. It is also packaged in cartons, each containing four cans.
Stow cool and dry with good ventilation.
Spices are hygroscopic goods, which interact with the moisture in the air. The risk of mould growth is naturally at its greatest in warm, humid air.
To ensure that the product does not become musty under the influence of moisture, the vanilla pods are packaged in cans.
Recommended ventilation conditions: air exchange rate: 6 changes/hour (airing).