Process of making cold water soluble tea concentrates and powders

Claim 2

A process for manufacturing cold water soluble tea concentrate and powder which comprises preparing a tea extract by extracting tea leaves with hot water, selectively removing nonphenolic compounds of high molecular weight comprising chlorophyll, protein, polypeptide and polysaccharide from said tea extract while retaining polyphenolic compounds therein by subjecting said tea extract to filtration through a gel or solid material which is capable of effecting the separation of said nonphenolic compounds of high molecular weight from said tea extract which contains said polyphenolic compounds and also caffeine and amino acids and then concentrating the resultant filtered tea extract to obtain a cold water soluble tea concentrate or powder.

Claim 3

A process according to claim 1 in which said nonphenolic high molecular weight compounds are selectively removed by filtering said tea extract through a gel selected from polymerized dextran and polyacrylamide.

Claim 4

A process according to claim 1 in which said nonphenolic high molecular weight compounds are selectively removed from said tea extract by filtration through porous glass granules.

Claim 5

A process according to claim 1 in which said nonphenolic high molecular weight compounds are selectively removed by ultra-filtration.

Claim 6

A process according to claim 1 in which said nonphenolic high molecular weight compounds including chlorophyll, protein, polypeptide and polysaccharide are selectively removed by adding a minor amount of an organic solvent which is miscible with water to said tea extract in an amount sufficient to prevent clogging of an ultrafiltration membrane and then passing the tea extract containing organic solvent through an ultrafiltration membrane effective to allow the passage therethrough of said tea extract including amino acids and caffeine but not the passage of said nonphenolic high molecular compounds and collecting the tea extract which has passed through said ultrafiltration membrane.

Claim 7

A process according to claim 1 in which said nonphenolic high molecular weight compounds are selectively removed by reverse osmosis.

Claim 8

A process according to claim 1 in which said material is selected from a gel of polymerized dextran or polyacrylamide, porous glass granules and an ultrafiltration membrane.

Claim 9

A process according to claim 1, in which said material through which said tea extract is filtered is selected from a member of the group consisting of gels of polymerized dextran and of polyacrylamide, porous granules of inert solid material and an ultra-filtration membrane.

Claim 10

A process according to claim 1 in which said nonphenolic high molecular weight compounds which include chlorophyll, protein, polypeptide and polysaccharide are selectively removed from said tea extract by percolating said extract through a gel of polymerized dextran or polyacrylamide, wherein said polyphenolic, compounds are retained and said high molecular weight compounds are not retained, discarding the turbid eluate emerging initially from said gel which contains said nonphenolic high molecular weight compounds, collecting the clear eluate which then emerges from said gel, washing said gel with a solvent to elute materials including polyphenols adsorbed on said gel, collecting the eluate from said washing and combining said clear eluate with said eluate from said washing to form tea extract free from nonphenolic high molecular weight compounds.

Claim 11

A process according to claim 3 in which said washing of said gel is carried out with a polar solvent selected from polar organic solvents and water.

Claim 12

A process according to claim 1 in which said nonphenolic high molecular weight compounds including chlorophyll, protein, polypeptide and polysaccharide are selectively removed from said tea extract by forcing said tea extract through porous glass granules, discarding the turbid eluate emerging initially which contains said nonphenolic compounds, collecting the clear eluate which then emerges, washing said porous granules with a solvent to elute materials including polyphenols adsorbed thereon, collecting the eluate from said washing and combining the clear eluates and the eluate from said washing to form tea extract free from said nonphenolic high molecular weight compounds.

Claim 13

A process according to claim 11 in which said solvent used for said washing is a polar solvent.