Selected high molecular weight gallotannins are incorporated into FD&C dye-containing foodstuffs to prevent staining of polymeric substrates such as wool or nylon rugs and clothing. Gallotannins from sumac leaves and Chinese nut galls are effective at levels of 50 ppm or below. This invention is useful in foodstuffs which are not subject to oxidation.
The invention consists of a process to improve the resistance to stains on yarns, on the basis of wool, silk, polyamide, polyacrilonitrile, natural and artificial cellulosic fibres and in general, all other synthetical fibres which can be dyed. According to the invention the yarns are treated during the dyeing process with an aqueous solution containing up to 5% tannic acid in acid medium. It is economically advisable to add a stabiliser to the solution to avoid oxidation of the solution and the fibres, and possibly a wetting agent. Preferably the treatment is made during the dyeing procedure, before, during or after the effective dyeing step.
The staining effect (particularly with respect to the staining of polyamides) of a colorant such as a dye used in foods and beverages is inhibited by a compound of the formula ##STR1## wherein: Z.sup.1, Z.sup.2, and Z.sup.3 are the same or different and are each a bridging radical or a direct bond, Ar.sup.1, Ar.sup.2, and Ar.sup.3 are the same or different and are aromatic or bicyclic radicals; Q is a fused, partially aromatic bicyclic radical, or Q is a carbohydrate residue having a non-repeating structure, in which case m is 1, or Q is a carbohydrate having repeating saccharide units, in which case Q along with its substituents is repeated m times, where m is the number of said repeating saccharide units, but when Q is not a carbohydrate residue, m is 1; R.sup.1, R.sup.2, and R.sup.3 are H or polyhydroxybenzoyl, R.sup.4, R.sup.5 and R.sup.6 are H or the residue of an esterified alcohol, x, y, and z are from 2 to 3, a, b, and c are from 0 to 1, n is from 0 to 1, except that when Q is an oligo- or polysaccharide having terminal saccharide units, n, in the terminal saccharide units, is from 0 to 2, and when n is zero, --Z.sup.1 --Q.sub.m --Z.sup.2 -- is optionally a direct bond. Examples of these stain-inhibiting compounds include tannic acid, green tea extract, epicatechin gallate, and the reaction product of gallic acid and a carbohydrate.
This invention provides compositions and methods providing, e.g., stable powder particles containing bioactive materials. The methods include, e.g., high pressure spraying of the bioactive materials in solution or suspension, with viscosity enhancing agents and/or surfactants. Compositions of the invention provide, e.g., high initial purity, high stability in storage, and reconstitution at high concentrations.
A low-staining orange food coloring composition and a process of producing such a food coloring is disclosed, as well as an orange colored beverage composition colored with such a food coloring composition and a process of producing such a beverage. The orange food coloring composition comprises a combination of a yellow dye selected from the group consisting of FD&C Yellow #5, quinoline yellow and combinations thereof and a red dye selected from the group consisting of carmoisine, Ponceau 4R, FD&C Red #40, amaranth and combinations thereof.
Methods of enhancing stain resistance of fibers, carpet yarns and carpets are disclosed. In one aspect, the invention relates to a method of treating fiber, yarn or carpet comprising applying an aqueous treating composition to fiber, yarn or carpet, wherein the aqueous treating composition comprises tannic acid heating the fiber, yarn or carpet to a temperature of at least about 160.degree. F.; applying a second topical treating composition to the fiber, carpet or yarn, wherein the second aqueous treating composition comprises a fluorochemical; and heating the fiber, yarn or carpet to a temperature of at least about 160.degree. F.
