Effect of different physicochemical de-tartration methods on red grape juice quality.

Grape contains a great deal of tartaric acid and minerals such as Potassium and Calcium which during ripening of grape increase in concentrations and result in potassium and calcium tartrate precipitation in grape juice. There have been different methods introduced for de-tartration but none of them have been completely successful. These methods can be categorized into two different groups of physicochemical and instrumental methods. In this study application of cold treatment, cream of tartar (Potassium bitartrate), Carboxymethyl Cellulose (CMC), and Mannoprotein were investigated. Then all these samples were stored at 5 °C to stimulate tartrate crystals precipitation and were investigated for color indices change, the amount of sediments, acidity, pH and taste. Among these methods addition of Mannoprotein and CMC were proved to have ability in stabilizing tartrate crystals in red grape juice.