GB975733A - Process for preventing haze formation in fermented beverages - Google Patents

Abstract

A polymer for preventing the formation of haze in a fermented beverage by the adsorption of haze-forming non-protein substances on the polymer, contains urea and/or urethane groups and may be obtained by the reaction of a polyisocyanate with water or with a polyhydric alcohol, or by reaction of the polyisocyanate with a polyamine, an amino alcohol, an amino carboxylic acid or a mixture of these, the reaction being carried out optionally in the presence of water and/or a polyhydric alcohol. Basic or metallic compounds capable of accelerating the reaction and a dispersing agent are included in the reaction mixture. Preferred polymers are obtained by the reaction of either a mixture of the 2:4 and 2:6 isomers of tolylene diisocyanate or hexamethylene diisocyanate with ammonia or ethylene diamine in aqueous solution. Polyisocyanates mentioned: hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, tolylene-2:4-diisocyanate or a mixture of the 2:4 and 2:6 isomers, p-xylylene diisocyanate, 3-(a -isocyanate-ethyl) phenyl isocyanate, and the reaction products of an excess of a diisocyanate with polyhydric alcohols such as trimethylol propane. Polyamines: ethylene diamine, hexamethylene-diamine, bis-hexamethylene triamine, pentaethylene tetramine and p-phenylenediamine. Amino alcohols: ethanolamine, triiso-propanolamine and 4-aminobenzyl alcohol. Amino carboxylic acids: glycine, amino caproic acid and anthranilic acid. Polyhydric alcohols: ethylene glycol, glycerol, trimethylol propane, pentaerythritol, mannitol, glucose, sucrose, polypropylene glycols and polypropylene triols. Accelerators; potassium acetate, sodium carbonate, sodium and potassium hydroxide, tertiary amines such as triethylamine, and metallic compounds such as stannous octoate and ferric acetylacetonate. Dispersing agents: long chain quaternary ammonium halide, an oxyalkylated phenol or an alkali metal salt of an alkyl or aryl sulphonic acid. The polyureas may be used either as powder or paste alone or in admixture with other non-toxic adsorbents. The powder may be ground and the paste dispersed by milling with gravel in the presence of surface-active agents and the absorptive properties may be regenerated after use by treatment with dilute aqueous sodium carbonate or caustic soda. The Specification discloses the preparations of five polymers which were employed to adsorb anthocyanogens from pale ale by shaking 0.2g (dry weight) of the polymer with 300 ml. of degassed ale for 10 minutes; the anthocyanogen removal amounted to 12, 28, 22, 23 and 21% respectively. (1) Tolylene-2:4-diisocyanate and tolylene-2:6-diisocyanate are added to a solution of the condensation product of octyl phenol with ethylene oxide in water at 20 DEG C. and caustic soda dissolved in water is added to the mixture. The suspension of polyurea obtained is stirred, filtered and thoroughly washed with water. In Examples 2, 3 and 4, the reaction mixture includes ammonia, ethylene diamine and hexamethylene diamine, respectively. In Example 5, hexamethylene diisocyanate replaces the mixture of tolylene diisocyanates.ALSO:The formation of haze in a fermented beverage is prevented or lessened by the adsorption of haze-forming non-protein substances on a finely divided insoluble polymer containing urea and/or urethane groups. The polymer may be obtained by the reaction of a polyisocyanate with water or with a polyhydric alcohol, or by reaction of the polyisocyanate with a polyamine, an amino alcohol, an amino carboxylic acid or a mixture of these, the reaction being carried out optionally in the presence of water and/or a polyhydric alcohol. Basic or metallic compounds capable of accelerating the reaction and a dispersing agent are included in the reaction mixture. Preferred polymers are obtained by the reaction of either a mixture of the 2:4 and 2:6 isomers of tolylene diisocyanate or hexamethylene diisocyanate with ammonia or ethylene diamine in aqueous solution. Polyisocyanates mentioned: hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, tolylene-2:4-diisocyanate or a mixture of the 2:4 and 2:6 isomers, p-xylylene diisocyanate, 3-(a -isocyanatoethyl) phenyl isocyanate, and the reaction products of an excess of a diisocyanate with polyhydric alcohols such as trimethylol propane. Polyamines: ethylene diamine, hexamethylene-diamine, bis-hexamethylene triamine, pentaethylene tetramine and p-phenylenediamine. Amino alcohols: ethanolamine, tri-iso-propanolamine and 4-aminobenzyl alcohol. Amino carboxylic acids: glycine, amino caproic acid and anthranilic acid. Polyhydric alcohols: ethylene glycol, glycerol, trimethylol propane, pentaerythritol, mannitol, glucose, sucrose, polypropylene glycols and polypropylene triols. Accelerators: potassium acetate, sodium carbonate, sodium and potassium hydroxide, tertiary amines such as triethylamine, and metallic compounds such as stannous octoate and ferric acetylacetonate. Dispersing agents: long chain quaternary ammonium halide, an oxylalkylated phenol or an alkali metal salt of an alkyl or aryl sulphonic acid. The polyureas may be used either as powder or paste alone or in admixture with other non-toxic adsorbents. The powder may be ground and the paste dispersed by milling with gravel in the presence of surface-active agents and the absorptive properties may be regenerated after use by treatment with dilute aqueous sodium carbonate or caustic soda. The Specification discloses the preparations of five polymers which were employed to adsorb anthocyanogens from pale ale by shaking 0.2 g. (dry weight) of the polymer with 300 ml. of degassed ale for 10 minutes; the anthocyanogen removal amounted to 12, 28, 22, 23 and 21% respectively. (1) 174 parts of an 80:20 mixture of tolylene-2:4-diisocyanate and tolylene-2:6-diisocyanate are added during 6 hours to a vigorously agitated solution of 10 parts of the condensation product of octyl phenol with 10 molecular proportions of ethylene oxide in 750 parts of water at 20 DEG C. Eight parts of caustic soda dissolved in 30 parts of water are added to the agitated mixture at such a rate during the addition of the diisocyanate that an alkaline reaction to red-litmus test paper is maintained. The suspension of polyurea obtained is stirred for 16 hours at 20 DEG C., filtered and thoroughly washed with water. There is obtained 650 parts of a white paste, the solid content of which is 53.5%. In Examples 2, 3 and 4, the reaction mixture includes ammonia, ethylene diamine and hexamethylene diamine, respectively. In Example 5, hexamethylene diisocyanate replaces the mixture of tolylene diisocyanates. The Specification acknowledges the prior use of the following materials in preventing the formation of haze in beverages: carbon, polyvinyl-pyrrolidone, polyvinylimidazole, poly(N-vinyl-5-ethyl-2-oxazolidinone), polyamides and polyacrylamides.