Petitgrain distillation in Paraguay
What is Petitgrain ?
Petitgrain is the natural extract obtained from the steam distillation of the leaves, branches and unripe fruits of the bitter orange tree (Citrus Aurantium, var. Amara).Generally about 70% of the product used in the perfume and cosmetics industry comes from Paraguay, where the raw material has developed a remarkable adaptability to the Paraguayan environment.
The essence distilled from Paraguay was born with the brainstorming of Benjamin Balansa (1825- 1892), a French botanist whose scientific activities took him to Indochina and the western hemisphere (Chevalier, 1942; Astre, 1947)
When Balansa arrived in Paraguay in 1875 to collect plants, he found much land east of the Paraguay River covered by naturalized citrus forests. Balansa, recognizing the potential for essential oil production even in this remote corner of South America, began distilling the oily parts of the bitter orange in 1876. At first, the flowers were processed to make neroli oil, while leaves and twigs produced petitgrain oil. Encouraged by these results, Balansa built a still of his own creation in Buenos Aires and brought it to Paraguay in 1877. In 1885, others also established 30 petitgrain operations in the country in an attempt to emulate Balansa's success (Bourgade, 1889).
Labor problems and negligible worldwide demand for the more expensive neroli oil focused commercial attention on distilling the leaves rather than the flowers.
Until the 1930s, essential oil production in Paraguay was dominated by several large producers, including a descendant of Balansa. Gradually, however, petitgrain production became largely a peasant activity, characterized by many small operations using crude equipment. Bitter orange cultivation and/or distilling of petitgrain are now in the hands of about 15,000 Paraguayan villagers and only a few large producers (Daniel W. Gade 1979).
Most of the farmers who grow bitter orange do not have their own distillation equipment and rent it from neighbors or sell the raw material to still owners who are also farmers. Most of the farms where bitter orange plants are grown cover less than five acres, with a quarter between five and ten acres. Although small, these farm units are diversified (Daniel W. Gade 1979).
Harvesting raw material
The material harvested from the cultivated bitter orange plant is mainly leaves, shoots, twigs and even small branches contain oil and are usually included in the raw material for distillation. The foliage of about 150 plants is needed to produce one kilogram of oil. The initial harvest, which produces selected leaves with a small percentage of woody matter, occurs two to three years after planting. The plants are productive thereafter for about 25 years, but are rarely allowed to grow into a fully developed tree. The main stem is cut close to the ground to encourage branching and to facilitate leaf collection. Constant close pruning of the branches inhibits the development of most flowers and fruit.Normally one, but sometimes two, three and even four annual harvests are made from the same plant. The frequency of harvesting depends on the price buyers will pay for the oil, the availability of farmers' time and labor, and the extent to which the fields are weeded. The rate at which new leaves develop, a function of temperature, rainfall, and soil fertility, also governs the number of times in a year that the shrub is cut. Growth is generally uninterrupted in this hot, humid climate, but photosynthesis is most rapid from October through March, and harvesting and distillation are most active in the warmer months (Daniel W. Gade 1979).
Highlighted map of Paraguay, in red the area of intensive cultivation of Citrus Aurantium Amara for harvesting.
Distillation
Harvested leaves are processed near plantations, as it is not economical to move the raw material long distances. The stills are in turn located near a water source, usually a small stream or occasionally a well. In keeping with the technological simplicity of rural Paraguayan existence, processing equipment can be operated and largely repaired by the farmers themselves. Local blacksmiths and carpenters produce almost all parts of the distillation unit.The use of copper parts in Petitgrain distillation equipment was made illegal in 1941 to counteract Moonshine production. The still is made of wood, galvanized iron or iron coated with wood, the last a trick to avoid an unpleasant smell that metal is said to impart to the essence.Most stills loaded in Paraguay can hold about 350 kg of foliage and twigs, although the capacity can vary from 200 to 800 kg. The raw material is trodden to compact it in the still, often in stages to ensure accurate distillation of all the raw material. When fully charged, the top of the still is secured with stones or metal clamps and sealed with red clay to minimize steam escape. The first distillation of the day, which involves cleaning the still, lighting the fire, and heating 200 to 400 liters of water, takes about five hours; subsequent loads are processed in half that time (Daniel W. Gade 1979).
The chemistry of fragrance, Charles Sell, 2006, chapter 3, p34,
Chemistry
Cas number: 8014-17-3
Significant qualitative and quantitative differences can be found for Petitgrain Bigarade oil. For example:
Limonene content varies from 0,14% al 43,57%,
Myrcene (Myrcene) from traces to 42,6%,
Sabinene from traces to 33,93%,
Linalolo (Linalool) from '1,02% to 71,04% e
Linalyl acetato (Linalyl acetate) from 3,45% to 56,8%.
(Luigi Mondello, Giovanni Dugo, Paola Dugo & Keith D. Bartle (1996) Italian Citrus Petitgrain Oils. Part I. Composition of Bitter Orange Petitgrain Oil, Journal of Essential Oil Research, 8:6, 597-609)
The distillation also produces an interesting hydrolate, with a woody/aromatic olfactory profile.
Petitgrain from Citrus Aurantium: Essential Oil of Paraguay, Daniel W. Gade 1979 - Economic Botany, Vol. 33, No. 1 (Jan. - Mar., 1979), pp. 63-71 )
Luigi Mondello , Giovanni Dugo , Paola Dugo & Keith D. Bartle (1996) Italian Citrus Petitgrain Oils. Part I. Composition of Bitter Orange Petitgrain Oil, Journal of Essential Oil Research, 8:6, 597-609, DOI: 10.1080/10412905.1996.9701026
http://dx.doi.org/10.1080/10412905.1996.9701026