Patent GB-806407-A (GB)
Title: Improvements in or relating to tobacco
IPC: A24B15/32
Filed: 1955-07-08
Abstract: Starch 3-methylvalerate is prepared, from a solution of dried starch in formamide with added pyridine, by adding 3-methylvaleryl chloride and pouring the resulting mixture, after standing, into cold 2 per cent hydrochloric acid, filtering and washing with ethyl alcohol.  A quantitative example is given.  Polyvinyl isovalerate is prepared by treating a boiling mixture of water and emulsifying agent with vinyl isovalerate and potassium persulphate, with additions of potassium persulphate during subsequent refluxing, the resulting polymer emulsion being steam-distilled, cooled and filtered and, if desired, coagulated by treatment with aqueous sodium chloride.  A quantitative example is given.  Organic carboxylic acids having from three to eight carbon atoms are used to esterify synthetic polymers or condensation products having free hydroxyl groups in the molecule. Suitable acids are the saturated and unsaturated aliphatic fatty acids (examples given), the cycloalkane or cycloalkene aliphatic acids (examples given), the aromatic carboxylic acids, such as benzoic or toluic acids, and phenylacetic acid; the volatile derivatives of the hydroxy acids or keto acids may also be used.  The compounds esterified may be polyvinyl alcohols prepared by the polymerization and subsequent hydrolysis of vinyl esters or of a mixture of a vinyl ester with vinyl ethers, crotonic acid, styrene or butadiene, or may be condensation products of polyvinyl alcohol with aldehydes or ketones; they may be substituted vinyl or allyl alcohol polymers or condensation products or may be glyptal, alkyd or phenol-formaldehyde type condensation products, or polyvinyl butyrals.ALSO:The Specification describes the following preparations of organic compounds for use in tobacco as flavour-producing agents (see Group VI):-Isobutylmalonic acid is prepared by reaction of diethyl malonate and isobutyl bromide, followed by saponification; 8-methyl-2,3,5-nonanetrione from 2,3-butanedione (biacetyl) and 4-methylvaleryl chloride; 2,12-dimethyl - 4,7,9 - tridecanetrione from 7 - methyl - 2,5-octanedione and 4-methylvaleryl chloride; decyl isovalerate from decyl alcohol and isovaleryl chloride; tartaric acid diisovalerate from tartaric acid and isovaleryl chloride; glyceryl triisovalerate from glycerine and isovaleryl chloride; sorbitol hexaisovalerate from sorbitol and isovaleryl chloride (or isovaleric anhydride); furfural isovalerate from furfuryl alcohol and isovaleryl chloride; glucose pentaisovalerate from glucose and isovaleryl chloride; fructose pentaisovalerate from fructose and isovaleric anhydride; sucrose octaisovalerate from sucrose and isovaleryl chloride; rhamnose triisovalerate from rhamnose and isovaleric anhydride; gluconolactone tetraisovalerate from glucono (delta) lactone and isovaleryl chloride; lignin 3-methylvalerate from lignin and 3-methylvaleryl chloride; maltol 3-methylvalerate from 3-methylvaleryl chloride and 2-methyl-3-hydroxypyrone.  The preparation of each ester is described in detail.ALSO:Tobacco is treated with an additive which, under normal tobacco storage conditions, is stable in contact therewith and substantially non-volatile but which, on smoking the tobacco, releases one or more volatile flavour-producing organic acids having at least three carbon atoms.  Suitable acids include saturated and unsaturated aliphatic fatty acids (examples given), cycloalkane or cycloalkene aliphatic acids (examples given), aromatic carboxylic acids, e.g. benzoic or toluic acids, and phenylacetic acid; volatile derivatives of hydroxy or keto acids may also be used.  A preferred acid is an aliphatic or alicyclic saturated monocarboxylic acid of the fatty acid series having four, five or six carbon atoms.  The additive itself may be an alkylated or arylated derivative of malonic acid or an aliphatic 1,3-diketone or derivative thereof; it is preferably an ester of the acid to be released and of a hydroxyl group containing compound. Examples of suitable compounds are given falling within these classes: (1) saturated or unsaturated acyclic aliphatic monohydric alcohols, (2) aliphatic hydroxy acids (tartaric, malic and citric acids are mentioned), (3) polyhydric alcohols, (4) alicyclic hydroxy compounds, such as mono- or polyhydroxy cyclohexanes, cyclohexenes, cyclopentanes or cyclopenenes, (5) aromatic hydroxy compounds, such as of phenolic type, (6) heterocyclic alcohols, such as the various hydroxy derivatives of furane, thiophene, pyrrole, pyridine, pyrone, or condensed heterocyclic ring compounds, such as indole (reference is made to furfuryl compounds as representative esters), (7) carbohydrate type compounds such as sugars, (8) lactones of certain sugar acids such as the aldonic and uronic acids, (9) compounds of the group consisting of high molecular weight polysaccharides, conjugated saccharides and lignins, such as starch, cellulose, pectin, lignin, dextrins, inulins, glycogens, lichenins, hemicellulose, pentosans, hexosans, natural gums and mucilages, glucosides and tannins, (10) enol forms of ketones containing the radical grouping <FORM:0806407/VI/1> and (11) synthetic polymers or condensation products having free esterifiable hydroxyl groups in the molecule, such as polyvinyl alcohol.  Application of the additive may be by spraying in an aqueous dispersion or in a solvent, such as alcohol ethyl ether or acetone, which is later driven off as vapour. The additive may be applied to tobacco before ageing and curing or, in the case of blended cigarette tobacco, to one or all of the blend constituents, e.g. in leaf form, or after blending.  The additive forms from 0.01 to 1.0 per cent by weight of a dry basis of the final tobacco product.  Quantitative application details are given: in one example, additive in a solvent which is later blown off by compressed air is injected into a one-inch portion of a cigarette.