Grape skin Extract

Grapeskin extract is soluble in water and water/ alcohol, but not in fats and oils. The colorant will slowly oxidize in aqueous solutions and the addition of ascorbic acid does not help. The colorant is very susceptible to ph changes and in a practical sense, is only used in products that are acidic in nature, i.e., ph 4 or below. There is gradual color change from red to blue-red, purple, steel blue, gray-green to dull yellow as the ph increases from 1 to 13. The ph not only affects color, but color intensity and color stability, each being best at ph 1 to 3.5. It is unstable to uv and visible light exposure. It was discovered that doubly acylated anthocyanin mixtures exhibited better stability to light, heat and oxidation than the mono-acylated anthocyanins obtained from grapeskins. A search for plant materials with high levels of naturally occurring doubly acylated anthocyanins led to grape varietal selection and to other anthocyanin containing vegetables, such as purple carrot, elderberry, red cabbage and red raddish. These sources are now commercially available from nutra food ingredients. Grapeskin extract has found application in water-based acid type beverages, jellies, candy, gelatin desserts, skin and hair care products, dry mixes, dark chocolate and cake mixes.