Abstract: Fat-soluble trace constituents contained in plant tissues may be conveniently concentrated and/or purified by a method which involves extracting the fat-soluble trace constituent from a plant, to obtain an extract containing the fat-soluble trace constituent; adding a fatty acid ester to the extract, to obtain a mixture; and subjecting the mixture to molecular distillation. The method is particularly effective for the concentration and/or purification of fat-soluble constituents which are solids or viscous liquids at ambient temperature and ordinary pressure. The concentrated and/or purified fat-soluble trace constituent of a plant tissue prepared by the method may be combined with a food or drink to afford a food or drink product that contains the concentrated and/or purified fat-soluble trace constituent.

Abstract: An antimicrobial agent comprising, as an active component, compounds represented by the following formula [wherein, R1 and R2 each independently represent H or an alkali metal atom.]; and a microbicidal agent comprising, as an active component, compounds represented by formula (I): [wherein, R1 and R2 each independently represent H or an alkali metal atom.], wherein they have high safety and little impact on the environment.

Abstract: Fat-soluble trace constituents contained in plant tissues may be conveniently concentrated and/or purified by a method which involves extracting the fat-soluble trace constituent from a plant, to obtain an extract containing the fat-soluble trace constituent; adding a fatty acid ester to the extract, to obtain a mixture; and subjecting the mixture to molecular distillation. The method is particularly effective for the concentration and/or purification of fat-soluble constituents which are solids or viscous liquids at ambient temperature and ordinary pressure. The concentrated and/or purified fat-soluble trace constituent of a plant tissue prepared by the method may be combined with a food or drink to afford a food or drink product that contains the concentrated and/or purified fat-soluble trace constituent.

Abstract: A process for producing hollow particles of crosslinked melamine resin having a uniform particles diameter, said process comprising subjecting a water-soluble methyl-etherified-melamine resin precondensate to condensation reaction in the presence of a curing catalyst in an aqueous solution containing a water-soluble polymer with carboxyl groups or water-soluble copolymer of ethylenically unsaturated carboxylic acid monomer, when the reaction liquid becomes turbid, adding to the reaction mixture a substance which dissolves or swells the melamine resin, and continuing the condensation reaction, if necessary.

Abstract: A process for producing the particles of crosslinked melamine resin having a uniform diameter in the following manner that water soluble precondensate of methyl-etherified melamine resin undergoes condensation reaction to give particles of crosslinked melamine resin having a uniform diameter, the condensation reaction is performed in an aqueous solution adjusted to a certain pH at 20.degree. to 70.degree. C., the aqueous solution contains a copolymer of acrylamide or methacrylamide with acrylic acid or methacrylic acid, a partial hydrolyzate of acrylamide or methacrylamide, or a saponified product of acrylonitrile, the pH adjustment is accomplished by an organic acid such as acetic acid, oxalic acid, formic acid, and p-toluenesulfonic acid, or an inorganic acid such as sulfuric acid and hydrochloric acid, which functions as a curing agent, and the preferred pH is in the range of 5 to 8.

Abstract: A process for producing hollow particles of crosslinked melamine resin having a uniform particles diameter, said process comprising subjecting a water-soluble methyl-etherified-melamine resin precondensate to condensation reaction in the presence of a curing catalyst in an aqueous solution containing a water-soluble polymer with carboxyl groups or water-soluble copolymer of ethylenically unsaturated carboxylic acid monomer, when the reaction liquid becomes turbid, adding to the reaction mixture a substance which dissolves or swells the melamine resin, and continuing the condensation reaction, if necessary.