Vanilla Curing
Farmers commonly sell the harvested beans at local markets, while exporters proceed with postharvest processes before exporting. Postharvest activities include preparation, withering, aging, and drying (in sunlight and shade) as well as conditioning (Figure 19.2). During preparation, freshly harvested beans are washed with water, followed by selection according to length, thickness, amount of damage, and physical blemishes or defects (Risfaheri and Rusli, 1995). Selected beans are subsequently withered by placing the beans in a wire or bamboo basket and immersed in hot water (between 63°C and 65°C) for 2–2.5 min. The purpose of withering is to terminate vegetative growth and trigger enzymatic activities, which induce the formation of vanillin.
FIGURE 19.2 Schematic representation of the processing of vanilla pods.
After draining, the beans are placed in a double-walled box for 24 h for the purpose of aging. Coconut fiber or sawmill is inserted between the wall layers as insulation, maintaining the temperature between 38°C and 40°C. The inner wall layer is covered with a relatively thick cloth to absorb moisture from the vanilla beans. The beans eventually become brownish in color with a greasy appearance.
The beans are dried on a black cloth on a drying bamboo tray for 2–2.5 h in the morning with occasional turning over. The beans are then covered with a black cloth and dried in the sun until afternoon when they are placed in a drying room. This process is repeated daily until the water content of the beans reduces to 55–60% and the aroma of vanillin is produced. From this point on the beans are dried away from direct sunlight in order to lower the water content gradually and increase the vanillin aroma. The vanilla beans are arranged in an orderly fashion on trays in a clean and cool ventilated room for 30–45 days, and regularly monitored for incidence of rot or mold. When the water content drops to about 30–35%, the beans are conditioned, using an oven maintained at a temperature of 50°C for 3 h. Conditioning is aimed at improving the vanillin aroma. Bundles of 50–100 beans are tied and wrapped in wax or paraffin paper, placed in a box coated with wax paper and stored in a cool dry room for 2–3 months. The beans are again regularly monitored for rot or mold, and if necessary, cleaned with alcohol. Beans with a weak aroma are further dried and returned to the conditioning process. After conditioning, the beans are graded and packed, ready for export.
Commercialization of Vanilla
The vanilla trade in Indonesia lacks structure and organization. In areas where the production is relatively high, exporters commonly have local agents to buy vanilla green beans direct from farmers in order to shorten the marketing chain. But in low production areas, the marketing chain is longer. Vanilla is sold from farmers to village traders, then from village traders to district traders, where it is sold to regency traders before reaching the exporters (Board of National Export Development, 1995).
The price of vanilla is strongly determined by the quality of the beans. Each country determines its own prerequisites. The common and specific sets of prerequisites, determined by the National Standard Board of Indonesia (SNI), are shown in Tables 19.1a and b. The United States prefer vanilla with low water content (20– 30%) for its use in the extraction industry. In Europe, vanilla is commonly used in households, therefore, the beans must be whole, with high vanillin content, sharp aroma, and 30–35% water content (Ruhnayat, 2005). The International Standard Organization (ISO) has determined prerequisites for the international market (ISO standard 5565-1:1999).
| Characteristic | Specifi cation | Testing Method |
|---|---|---|
| Aroma | Fragrant, specific vanilla | Organoleptic |
| Color | Shining, brown to dark brown | Visual |
| Beans | Compact, greasy, elastic to rather stiff | Organoleptic |
| Alien thing | Free from alien thing | Visual |
| Molds | Free from molds | Visual |
| Characteristic | Prerequisite | Testing Method | |||
|---|---|---|---|---|---|
| Quality IA | Quality IB | Quality II | Quality III | ||
| Form | Whole | Whole | Whole/cutting | Whole/cutting | Visual |
| Size of whole beans | 11 | 11 | 8 | 8 | SP-SMP320-1980SP-SMP320-1980 |
| Split beans and cutting | 5 | None | None | None | SP-SMP7-1975 |
| Water content, max (%) | 38 | 38 | 30 | 25 | SP-SMP320-1980 |
| Vanillin content, max (%) | 2.25 | 2.25 | 1.50 | 1.00 | SP-SMP35-1975 |
| Ash content, max (%) | 8 | 8 | 9 | 10 | |