Title of Invention

AN APPARATUS USEFUL FOR STEAM DISTILLATION OF AROMATIC MATERIALS

Abstract

The present invention relates to an apparatus useful for steam distillation of aromatic materials. The main utility of the present invention is its use as an analytical apparatus for the determination of steam volatile essential oil content in natural materials like spices and herbs. The unit is also a valuable tool for sample preparation and in Research and Development work. The novelty of the invention is that, for the first time, an apparatus for steam distillation of volatile oil from spices and herbs suitable for laboratory analytical work and for sample preparation work has been disclosed. The inventive features are the design of the oil- water separator trap which can be used for distillation of volatile oils which are heavier than water as well as for distillation of volatile oils which are lighter than water and also for a mixture of the two types of oils and the distillation system has built-in safety features and can be operated without break, for a given batch of distillation.

Full Text

The present invention relates to an apparatus useful for steam distillation of aromatic materials. The main utility of the present invention is its use as an analytical apparatus for the determination of steam volatile essential oil content in natural materials like spices and herbs. The unit is also a valuable tool for sample preparation and in Research and Development work. The essential oil or volatile oil present in certain natural materials is responsible for imparting them a characteristic aroma and flavour. The flavour quality is many materials is very much dependent on the amount of such volatile oil naturally present in them. In the present patent proposal, the design and application of a direct steam distillation unit, meant for the distillation and estimation of volatile oil are covered. This is a new apparatus and no such equipment has been described in patent literature. It may be mentioned that steam distillation units for the production of spice oils in large quantity are commercially available. But the present invention specifically deals with the design of a glass apparatus which is especially useful for determination of volatile oil content and sample preparation. Reference may be made to the US patent No: US4869785 (1989) wherein a large scale steam distillation unit using saturated steam under reduced pressure, completely automated and controlled by a computer to regulate the density of the distillate by regulating the temperature of the material to be steam distilled is described. The coverage and usage of this apparatus are entirely different as exemplified by the distillation of a charge namely protein hydrolysate of the order of 8000 kg/hr to obtain a liquid seasoning with very low level of DCP. Reference may also be made to US patent No: US5304287 (1994) wherein a microdistillation apparatus comprising of a microditillation column, a collector tube and a hydrophobic membrane useful for the quantitative distillation of pollutants in samples of environmental waters and sludge for the recovery of compounds such as cyanide, phenolic compounds, hydrogen fluoride, ammonia, and sulfites is described. The membrane helps in quantitatively trapping the polluting volatile compounds. The coverage and usage of this apparatus are also entirely different from the present patent proposal. Reference may be made to the analytical determination of volatile oil by the conventional hydrodistillation method wherein 10-100 gm of representative sample of the test material is powdered and taken in a flask along with sufficient water (about one litre) and anti-foaming agent, connected to a oil-water separation trap fitted with a water cooled condenser and the sample is distilled for about 4-5 hrs. In this process, the steam carries along with it the volatiles in the sample, gets condensed and collected in the trap. The volatile oil layer remains in the trap and water conies back to the distillation still. At the end of distillation the volume of oil collected can be directly measured on the graduated trap. The drawbacks associated with traditional hydrodistillation methods are : (1) it is time consuming, the usual duration of distillation being of the order of 4 to 6 hrs; (2) the energy requirement is also high; (3) the spent material is not amenable for further evaluation as it gets cooked with a large volume of water; (4) chemical changes such as hydrolysis can take place in the volatile constituents; (5) two separate traps will be necessary to collect volatile oils which are lighter than water or heavier than water; (6) bumping and foaming of the material are encountered sometimes during distillation; (7) the antifoam compound used to suppress foaming during distillation could itself release some volatiles which may be distilled along with volatiles of the sample; (8) being produced by hydrodistillation method, the physical quality and chemical composition of the volatiles may not match the volatile oil obtained commercially by direct steam distillation method. The main object of the present invention is to provide an apparatus useful for the steam distillation of aromatic materials like spices and herbs which obviates the drawbacks as detailed above. Another object of the present invention is to provide an apparatus for the preparation of samples of volatile oil employing direct steam distillation. In the drawing accompanying this specification figure 1 represents an analytical apparatus for direct steam distillation of volatile oil. Figure 2 represents a distillation apparatus for the preparation of the samples of volatile oil. Accordingly the present invention provides an apparatus useful for steam distillation of aromatic materials as depicted in Figure 1 which comprises; a steam generation facility (5) such as an electrical heated two-necked flask capable of holding about 3 liters of water, the upper neck of the said two-necked flask being provided with two outlets, characterized in that one of the said outlets of the said flask (5) being a side outlet being connected to a water seal tube (8) capable of acting as a steam release, the other outlet at the top of the said flask (5) being provided with two sub-outlets, one of which being connected to a gadget (4) capable of directing steam through the bottom of a material holder (3) having a false bottom amenable for passage of steam, the top and of the said material holder (3) being connected to a condenser assembly (2), the said condenser assemble (2) being connected to an oil water separator (1) having graduations; the other outlet of the said top outlet of the said flask (5) being connected through an inlet tube with ring seal (6) through a funnel like device (7) having an air went capable of collecting condensed water from the said oil water separator (1). The water seal tube(8) has a safety feature for release of excessive steam and as a variant of the above apparatus for preparation of volatile oil samples essentially as depicted in Fig. 2 with component parts numbered 9-16, having oil-water separator (9) for efficient separation of the condensed volatile oil either heavier than water or lighter than water or for the mixture containing both the fractions, and with graduations and a water seal for release of pressure due to non condensed gases, double walled condenser assembly (10) for efficient cooling and condensation of steam and volatile oil mixture, a material holder (11) to hold material of varying sizes such as 0.5 kg to 1 kg with a suitable false bottom and amenable for the passage of steam, a gadget (12) for directing steam to material holder an to collect and retain any condensate dripping from the material holder and to collect and retain any condensate dripping from the material holder, with provisions to attach a water seal tube for releasing excessive steam when pressure is developed in the system, and a provision for release of steam to control the rate of distillation, steam generation unit made of silica with electrically heated coils of varying capacity suitably insulated from water with one of the necks connected to an inlet tube with ring seal (14), the other end of the ring seal connected to safety device (16) having a three way tube, one end of safety device being connected to funnel like device (15) with air vent to collect the condensed water from the oil-water separator, and the third end of the safety device being connected to the top end of the material holder through a ring seal tube, or alternatively the steam generation unit consisting of a round bottomed flask as described in the analytical unit above but with a capacity of 5 to 10 litres having two necks with one neck connected to the material holder and safety device and the second neck connected to water seal tube as described above. In an embodiment of the present invention, the unit can be used as hydrodistillation apparatus by dispensing with the material holder, taking the sample along with water in the round bottomed flask and directly linking to condenser-trap assembly. In another embodiment of the present invention the steam produced by any other steam sources being linked to material holder and rest of the assembly for distillation. In yet another embodiment of the present invention the said steam generation unit, material holder and condenser can be made of any other material such as metal or combination of any other materials of construction. In still another embodiment of the present invention the said oil-water separator can be linked to any other suitable condenser(s). A typical operation schedule involving the analysis of volatile oil content in a test material is described. The material holder is fitted with a suitable porous false bottom, over which the test material powdered to a suitable mesh size (22-30 US) is loosely packed. The safety tube is filled with water and led to the sink through a flexible tubing. The material holder along with the condenser-trap assembly is linked to the steam generator, with the water brought to boil. The oil-water separator is previously filled with water upto the top bulb. The flexible tube from the steam generator is connected to the oil-water separator. The steam from the generator passes through the bed of the material, carrying along with it the volatiles of sample and reaches the condenser. The steam along with the volatiles condense together and collected in the oil-water separator. The volatile oil which is heavier than water settles at the bottom and which are lighter than water floats at the top. Excess water flows back to the steam generator through the inlet tube with ring seal. The rate of steam generation in the flask is adjusted to a optimum level so that the condensate is almost at room temperature. The duration of distillation is governed by factors like nature of the test material, capacity of condenser and rate of steam generation which can be optimized. The source of steam is put off once distillation is over and the volume of oil collected is read on graduated tube. The oil can be drained out from bottom stopcock for further analysis. The following examples are given by way of illustration of the present invention and therefore should not be construed to limit the scope of the present invention. Example -1 One hundred gm of whole black pepper was powdered in a lab plate mill to a pass through 30 mesh size. 20 gm of the pepper powder was uniformly filled in the material holder and distilled in the analytical unit for 2 hrs as explained. The volume of oil collected was 0.5ml. In a parallel estimation 20 gm of above pepper powder subjected to conventional hydrodistillation for 4 hrs yielded 0.5 ml of volatile oil. Example -2 Two hundred gm of dried ginger was powdered to pass through 60 mesh sieve. 20 gm of ginger powder was uniformly mixed with 40g of an inert support of around 22 mesh size and distilled in the analytical unit for 2 hrs as explained. The volume of oil collected was 0.5ml. In a parallel estimation 20 gm of above ginger powder subjected to conventional hydrodistillation method for 4 hrs yielded 0.5 ml of volatile oil. Example -3 Two hundred gm of dried coriander seeds were powdered to pass through 30 mesh sieve. 100 gm of coriander powder was distilled in analytical unit for 2 hrs as explained. The volume of oil collected was 0.2 ml. In a parallel estimation 50 gm of above coriander powder subjected to conventional hydrodistillation for 4 hrs yielded 0.1 ml of volatile oil. Example 4 Forty gm of pepper powder prepared as explained in example 1 was hydro distilled with 1 lit of water in the analytical unit for 4 hrs yielded 1ml of volatile oil. Example 5 Three hundred gram of powdered black cumin was charged into the material holder of the sample preparation unit and steam distillation was carried out for 2 hours as explained. The volume of oil collected at the end of distillation was 0.55 ml. In a parallel study using hydrodistillation, the 300 gm of same material yielded 0.6 ml after 4 hours of distillation. The main advantages of the present invention are 1) The time of distillation is lower (2 hrs) and a large number of samples can be handled in a working day. 2) Constant supervision is not required during distillation and the unit can be conveniently run for a desired period of time 3) Use of antifoam, an expensive chemical, is avoided and possible contamination of co-distilled volatiles due to the antifoam is also avoided. 4) There is provision for options in the source of steam, material holder and the trap for oil collection in order to handle raw materials of varying volatile components such as those are rich in oil (eg cloves), those are intermediate in oil content (eg pepper & ginger) and those are low in oil content (eg coriander seed) and right type of condenser-traps assembly analytical detrmination or for sample preparation. 5) The trap is provided in design and construction that it can retain both types of oils viz., those lighter than water and those heavier than water. Besides, it can separate & retain a mixture of the two. 6) Energy consumption per analysis is low. 7) The unit can be operated under cohobation mode as normally practised wherein the condensed water is returned to the stem generation unit. 8) The unit can be used as hydrodistillation apparatus by dispensing with the material holder, taking the sample along with water in the round bottomed flask and directly linking it to the condenser -trap assembly. We claim 1. An apparatus useful for steam distillation of aromatic materials as depicted in Figure 1 which comprises; a steam generation facility (5) such as an electrical heated two-necked flask capable of holding about 3 liters of water, the upper neck of the said two-necked flask being provided with two outlets, characterized in that one of the said outlets of the said flask (5) being a side outlet being connected to a water seal tube (8) capable of acting as a steam release, the other outlet at the top of the said flask (5) being provided with two sub-outlets, one of which being connected to a gadget (4) capable of directing steam through the bottom of a material holder (3) having a false bottom amenable for passage of steam, the top and of the said material holder (3) being connected to a condenser assembly (2), the said condenser assemble (2) being connected to an oil water separator (1) having graduations; the other outlet of the said top outlet of the said flask (5) being connected through an inlet tube with ring seal (6) through a funnel like device (7) having an air went capable of collecting condensed water from the said oil water separator (1).

Documents:

387-del-2001-abstract.pdf

387-del-2001-claims.pdf

387-del-2001-correspondence-others.pdf

387-del-2001-correspondence-po.pdf

387-del-2001-description (complete).pdf

387-del-2001-form-1.pdf

387-del-2001-form-18.pdf

387-del-2001-form-2.pdf