US2264745A - Tobacco - Google Patents

Description

I l r b w J '1 e ec r dt r iv those. obtainable by' .the of ammoniacal hy- Patented Dec. 1941 PATENT OFFICE r it I ItalphBQElliot't, Snyder, N. Y.",'assignor to a. I. du Pont de-Nemonrs & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application March 8,,l9-t0,

Serial No. 322,991 i @Claims. (Cl. lei-142M This invention relates to the treatment ottobacon in order to improve its color and aroma.

More particularly, itrelates to the treatment of tobacco with an ammoniacal solution ot-hydrogen peroxide for the purpose of bleaching the to-- bacco and improving its quality, which treatment is carried out by spraying on the tobacco a cooled ammoniacal solution of hydrogen peroxide.

In the past it has been proposed to treat tobacco' with solutions of hydrogen peroxide by spraying the tobacco leaves with a'solution of the peroxide rendered alkaline by the presence of ammonia therein. It has now been found that when this ammoniacal solution or hydrogen peroxide is applied in the coldstate to the tobacco to be bleached the quality and color of the resulting product are much improved over that of tobacco which hasbeen bleached with'ammoniacal solutions of hydrogen peroxide applied at room temperature or at temperatures more elevated than room temperature.

Accordingly, it is an object of this invention to secure the maximum bneficiation of tobacco which is'to be subjected to, the action or. an ammoniacal solution ofhydrogen peroxide by spraying on the tobacco tov be bleached a cooled solution of the treating agent. This invention involves, therefore, the use of. cooled solutions of hydrogen peroxide, solutions cooledto 10 C. or below, for the purpose or securing the maximum improvement in the tobacco treated with these solutions as regards the color, aroma, and taste of the resulting product.

ammoniacal solution of le -KW a t mperuall .-bleach1n8 results over drogen peroxide solutions at room. temperature I I when theso'lution ofv hydrogen-peroxide'has been cooled only to atemperaturewithinthe range-10 "toC.

In the past, wherever animoniacal solutions of hydrogen peroiddehave been employed, the temperature of those solutions has been at least room temperature C. or higher), or in many cases me ih t above room temperature; In the commercial bleaching oftobacco-with ammoniacal solutions of hydrogen peroxide it had, in fact, been ordinarily supposed that the higher the temperature of the ammoniacal solution of hydrogen peroxide applied, the more efficient were the bleaching and aroma improving results obtained. This conclusion was based on the general chemical knowledge that reactions between oxidizing agents and materials'capable of oxidation proceeded more rapidly at higher temperatures.

Surprisingly enough, I have now discovered that the cooler the ammoniacal solution of hydrogen peroxide applied to the tobacco to be bleached,jthe more effective is the treatment as regards the improvement in quality or the to- I bacco. This discovery contravenes both general a chemical principles and prior established practice in this industry, which had regarded a temperature of at least room temperature or, where possible, temperatures higher than room temperature as essential in order to secure most satisfactory utilization of the hydrogen peroxide Ior the bleaching and improvement of the-tobacco.

fated atroom tempera r .with 'an ammonia'cal solutionpr emperatureof 5 C; (41?? preferable. However-.1

The ammoniacal solution of hydrogen peroxide may be cooled to a temperature oi 10 C. or below in any convenient manner. For example, the solution may be prepared by using refrigerated water, or water cooled to a temperature as close to 0? C. as possible. After the preparation of the solution by the addition of the ammonia or ammonia water to the dilute solution of hydrogen peroxide,

satisfactory cooling may be secured by introducing a block of ice into the solution, or the solution may be prepared in a tank provided with suitable refrigeration coils. In many cases where asource of; cooled water is available, no special cooling ,oI-the solution may be necessary, as the Solution'may h'aveait'er preparation a temperatures! 10f- C." or:below;simply because 01 the low temperature of the-water used in preparing it.

As examplesormy improved process for imprOvinithe quality 'o f,t0bacco by spraying that I tobacco with an'ammoniacal solution of hydro-j gen iperoxideg which ammoniacal solution has a temperature of 10 C. or below, the following may be given:

Example 1 A solution was prepared by mixing pounds or commercial Volume hydrogen peroxide solution with 65 pounds of tap water having a temperature of about 15 to 20 C. Commercial hydrogen peroxide solutions are usually sold in solutions or 100 Volume Concentration, i.- e. 1 cubic centimeter of the solution measured at 20 C. will yield 100 Volumes of oxygen gas measured at C. and 760 mm. mercury pressure. A solution of 100 Volume Concentration contains 27.6% H202 by weight and substantially 30.0% H20: by volume. pared, containing 'equalamounts of commercial 100 Volume hydrogen peroxide, solution and water had an H2O: concentration by'weight of-a'pproximately 13.8%.

To the solutionof hydrogen peroxide there was then added 5 pounds of aqua ammonia (the aqua ammonia solution having a specific gravity of 0.91). This resulted inan ammoniacal solution of hydrogen peroxide having a pH of approximately 9.5.

The resulting solution was then cooled by the introduction of a piece of ice to a temperature- It is evident that the solution as preof substantially 8 C. The solution,thusc00led,

was then used to spray 500 pounds of steamed} l 2 tire spraying process requiring approximately-f one hour. During this entire period care was and stemmed burley fermented tobacco; the en-a taken to insure the maintenance of a temperature of approximately 8 C. in the ammonia al solution, of hydrogen peroxide sprayed on the tobacco. In any event, during the major portion of the spraying, care was taken to insure a temperature of 10 C. or below.

1 It'may be remarked that ii. the temperature is 10 C. or below during the major portion of the spraying step, the temperature may safely be permitted to go somewhat abovefthis figure especially during the latter portion of the spraying without interfering with the improved results obtained with my process.

The tobacco was then piled on the floor, covered with canvas, and allowed to react. After several hours, it was thoroughly dried to the:

bone-dry condition (6 to 8% moisture content) and subsequently remoistened prior to its utilization in the manufacture of pipetobacco and cigarettes.

Example 2 As a comparison experiment, the same solution described in Example 1 was prepared, but the solution was not cooled to a temperature below 10 C., but was utilized to spray the same burley tobacco at room temperature which was 20.5 C. (69 F.). No means were provided for cooling the tobacco, either before or during the spraying, so that the temperature rose somewhat above this value during the spraying process.

After spraying, the tobacco was piled, covered with canvas, and allowed to react as in the preceding example. After several hours reaction, it was thoroughly dried to the bone-dry state (6 to"8% moisture content) and subsequently remoistened by the addition of water, exactly as in the preceding example.

Upon examination, thev tobacco had not been 'irnproved very much in color and was distinctly 1 darker than the tobacco prepared in accordance "with Examplel. Moreover, when manufactured into cigarettes and smoked,the tobacco was found to be harsh and the aroma; was much less pleasant than that of the tobaccdprepared in accordance with Example 1. 7

It will be apparent that while if have described certain preferred embodiments of my invention,

many changes and modifications may be made thereinwithout departing from the spirit of the invention. It is therefore my desire that the scope of the invention be determined in accord- Although the original tobacco 'was relatively dark in color and harsh in quality, the tobacco, at the conclusion of the bleaching step, was bleached to a very satisfactory light color. Moreover, its quality had been much improved, the resulting product being mild in character and very pleasant in aroma.

ance with, the prior art and the appended claims.

l. 'A process for improving the quality of tobacco which comprises spraying said tobacco with an ammoniacal solution of hydrogen peroxide maintained, during the major portion 0! the spraying process, at a temperature below 10 C.

2. A process for improving the quality of tobacco which comprises spraying said tobacco with an ammoniacal solution of hydrogen peroxide 'maintained, during the major portion of the spraying process, at a temperature below 5 C.

RALPH B. ELLIOTT.