Method of processing tobacco and its by-products

Description

FIELD

This invention concerns a method of processing tobacco and its by-products to provide a tobacco end product having improved sensory attributes.

DESCRIPTION OF RELATED ART

Currently in the art, in order be provide tobacco with improved sensorial attributes, such as flavor and taste, additives such as sugars, cocoa, licorice, cocoa, honey, polyethyleneglycol (PEG), and ammonia based additives such as ammonium hydroxide, urea and diammonium hydrogen phosphate (DAP), need to be added to the tobacco before submitting the tobacco to toasting. Toasting a process whereby the tobacco is heated in a dry environment. These additives tend to be increasingly avoided due to more restrictive recent regulations. Therefore sensorial attributes of tobacco can no longer be improved by conventional additives and toasting processes.

Additionally tobacco which is currently used in cigarettes, cigarillos, cigars and other tobacco products, tends to have a high ammonia content. Disadvantageously a high ammonia content can cause lung and throat irritation when the tobacco is smoked.

It is an aim of the present invention to obviate or mitigate at least some of the above mentioned disadvantages

SUMMARY

According to the present invention there is provided a method of processing tobacco and its by products, comprising the steps of, heating tobacco and its by-products to between 10°-170° Celsius; applying a pressure to the tobacco and its by-products of between 0-40 bar; and extruding said tobacco and its by-products from an extruder; to cause a Maillard reaction in the tobacco and the by-products.

The method may comprise the step of adding water to the tobacco and by products before they are heated.

The tobacco and its by-products is heated for a period of between 1-3 minutes. The tobacco and its by-products is heated wet; in other words as the tobacco and its by-products is heated 5 wt % to 20 wt % of water is added to the tobacco.

Advantageously the method of the present invention enables tobacco and its by-products, to be provided with improved sensorial attributes, such as flavor and taste, without requiring additives or submitting the tobacco and by-products to toasting. The Maillard reaction which occurs in the tobacco improves the taste of the tobacco. Furthermore, when the tobacco and its by-products are heated and pressurized, the ammonia evaporates; the results in a reduction in the ammonia content present in the tobacco and by products, thus further improving the sensorial attributes of the tobacco and by products.

Typically the tobacco and its by-products will be for use in cigarettes, cigarillos, cigars and other tobacco products.

Preferably the steps of heating, applying a pressure, and extruding, the tobacco, are carried out simultaneously.

Preferably the Maillard reaction is such that the ammonia content of the tobacco is reduced.

Preferably Maillard reaction is such that sensorial characteristics of the tobacco are changed.

The method may further comprise the step of cooling the extruded tobacco.

The step of cooling the extruded tobacco comprises trailing the extruded tobacco through air.

The step of cooling the extruded tobacco may be carried out by pressurized air which is provided by a pneumatic means, wherein the pressurized air is also used to move the extruded tobacco to another processing stage.

The method may further comprise the step of storing tobacco raw materials, which are useable to provide said tobacco for processing, in one or more silos.

The method may further comprise the step of processing tobacco raw materials to provide said tobacco for processing.

The step of processing the tobacco raw materials may comprise milling the tobacco raw materials.

The step of processing the tobacco raw materials may comprise sieving the tobacco raw materials.

The step of processing tobacco raw materials may comprise milling the tobacco raw materials and sieving the milled tobacco raw materials, so as to provide tobacco of a desired gradation and to reduce the amount of impurities within the tobacco. Preferably the tobacco raw materials are milled to so that they have particles sizes of between 200-400 microns.

According to a further aspect of the present invention there is provided a tobacco product comprising tobacco and tobacco by-products.

The tobacco product may be a cigarette, cigarillo, or cigar.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood with the aid of the description of an embodiment given by way of example and illustrated by the figures, in which:

FIG. 1 shows a side view of a processing plant comprising an extruder and which can carry out the method of the present invention; and

FIG. 2 illustrates a detailed view of the extruder, according to an embodiment.

DETAILED DESCRIPTION OF POSSIBLE EMBODIMENTS

A method for processing tobacco and its by-products such as to provide the tobacco and its by-products with improved sensorial attributes, such as flavor and taste is disclosed herein. FIG. 1 provides a side view of a processing plant 100 which can be operated to carry out the method of the present invention.

Tobacco and its by-products are provided as raw materials. The tobacco may comprise Burley, Galpão (Barn) Burley, Virginia and Oriental tobacco. Tobacco by-products can comprise, for example, tobacco residues such as powder, sieve residue, scraps, stems, shorts, tobacco dust swept from the factory floor, etc.

The raw materials are stored, in bulk, in silos 1 for any useful period of time. The raw materials are then processed by milling using a milling device 2, for example, hammer mills or rotative mills. In a further process step, the milled raw materials are sieved using a sieving device 3, for example, a plan sifter, to provide raw materials which have a particle size less than 500 microns, preferably less than 250 microns, and more preferably less than 50 microns, and which are substantially free of impurities.

The processed raw materials are further mixed in a mixing device 5 to form a blend. The blend is thus a mix of different tobacco types (Virginia, burley, oriental) and tobacco by-products which have predefined sensorial attributes. Typically, the mix comprises a content of by-products comprised between 5 and 20 wt % of the tobacco and tobacco by-products.

The blend is then stored in silos 6. The blend is further charged from the silos 6 to an extruder 7 via an extruder inlet 71. A detailed view of the extruder 7 is illustrated in FIG. 2, according to an embodiment.

Water (or steam) is added to the extruder 7, via a water inlet 72, such as to provide the blend with a predetermined moisture content having a value comprised between 1% and 50%. Adding water allows for promoting the gelatinization of starch comprised in the blend. Preferably, the moisture content of the blend to a value comprised between 10 wt % and 40 wt %, or between 15 wt % and 35 wt %, or preferably between 5 wt % to 20 wt %.

The blend is then extruded at a temperature 74 of 10° C. to 170° C. and a pressure 75 of 0 bar to 40 bar to provide an extruded product. Nitrosamines and ammonia contained in the blends are evaporated with the combined action of pressure and temperature and can thus be extracted from the blend via an outlet 73 provided in the extruder 7. Temperature and pressure are determined according to the amount of nitrosamines and ammonia contained in the blends prior to extrusion. Higher temperature and pressure values are used for blends containing higher amount of nitrosamines and ammonia.

The amount of nitrosamines and ammonia initially contained in the blends and the content of nitrosamines and ammonia in the extruded product can be determined by any suitable standard chemical analysis such as ion gas chromatographically analysis or high performance liquid chromatography (HPLC). In an embodiment, the extruded product has a reduced ammonia and nitrosamines content of less than 0.3%.

The amount of the nitrosamines and ammonia to be extracted from the blend, or the content of nitrosamines and ammonia in the extruded product, is based on sensory attributes of the extruded product. Sensory attributes of the extruded product can be determined by standard methods for sensory evaluation, for example, using professional tobacco expert panel. The measured sensory attributes can then be correlated with the measured content of nitrosamines and ammonia in the extruded product.

The combination of predetermined moisture content of the blends, and temperature and pressure in the extruder 7 is further arranged such as to provide the Maillard reactions within the blends further modifying the sensory attributes of the resulting extruded product. In fact, the Maillard reactions should occur in the whole range of temperatures and pressures used. Conditions provided during the process of the present invention are such that certain components of the blends (e.g., naturally occurring sugars and ammonium) undergo the Maillard reactions or “browning reactions” to form flavorful and aromatic compounds including pyrazines.

The temperature and pressure should be selected such that the amount of nitrosamines and ammonia is decreased below a threshold value during the duration of the extrusion process that is comprised between about 1 and 3 minutes. The temperature should thus be as high as possible in order to remove a maximum amount of nitrosamines and ammonia but yet avoiding burning of the blend. Burning of the blend results in a deterioration of the sensory attributes of the blend. Moreover, the removal rate of nitrosamines and ammonia and the onset of deterioration of the sensory attributes of the blend depend on the mix of different tobacco types and tobacco by-products.

In a further step, the extruded product is cooled in the extruder 7 by trailing it through a cold air inputted into the extruder by an air inlet 76. Cold air can be provided by a fan blowing a stream of cold air to the air inlet 76 via an air pipe 8. It should be understood that any other suitable cooling methods which use a stream of air to achieve cooling, may be used.

Extruded blend is carried out by pressurized air which is provided by a pneumatic means, wherein the pressurized air is also used to move the extruded tobacco to another processing stage.

The humidity content in the extruded product is further reduced by suction, for example through the outlet 73, such as to provide an end product having a final moisture content comprised between 9 wt % and 14 wt %. The final moisture content can be determined using an automatically pump with flow meter, or by using any other suitable method.

The method can further comprise a step of sieving the extruded product such as to eliminate fines or powders.

The end product is tested for its sensory attributes using any suitable sensory evaluation, such as the professional tobacco expert panel mentioned above.

In an embodiment, the blend is heated to a temperature comprised between 20° C. and 150° C. The blend can also be advantageously heated to a temperature comprised between 50° C. and 150° C. Preferably, the blend is heated to a temperature comprised between 100° C. and 150° C. The latter temperature range yields best sensory attributes for most mixes of different tobacco types and tobacco by-products. In a yet preferred embodiment, the blend is heated to a temperature of about 130° C.

Preferably, the blend is extruded at a pressure comprised between 5 and 20 bar such as to obtain best sensory attributes for most mixes of different tobacco types and tobacco by-products and best extruding performance. In a preferred embodiment, the blend is extruded at a pressure of about 12 bar. The Maillard reactions will occur in the blend for all the ranges of temperatures and pressures mentioned above.

Mechanical compression of the blend during the extrusion process from the extruder inlet 71 to the extruder outlet 73 will provide the extruded product with a particular shape. The extruder 7 can comprise a tool (not shown) at the extruder outlet 73. For example, the tool can be adapted to provide the extruded product with a substantially cylindrical shape.

In a further step, the end product is packaged using a packaging device 9 adapted to package the end product in a paper box.

The end product having the low nitrosamines and ammonia content and a moisture content comprised between 9 wt % and 14 wt % can be used in cigarettes, cigarillos, cigars and any other tobacco products.

An advantage of the method disclosed herein is to improve the sensory attributes of blends comprising tobacco and tobacco by-products by reducing the nitrosamines and ammonia content and providing the Maillard reactions. The method requires neither the use of additives nor toasting. The method brings important benefits to the whole tobacco production chain, mainly for Burley tobacco, since its use is being more and more restricted because of the high content of sensory additives and toasting.

REFERENCE NUMBERS AND SYMBOLS

1 silos

2 milling device

3 sieving device

5 mixing device

6 silos

7 extruder

71 extruder inlet

72 water inlet

73 outlet

74 temperature

75 pressure

76 air inlet

8 air tubing

9 packaging device

100 processing plant