Malic acid is a crystalline white solid with a melting point of 100°C. It is water soluble and less hygroscopic as compared to others, so as to provide a good storage shelf-life
Malic acid has a smooth, tart taste that lingers in the mouth without imparting a burst of flavour. Malic acid is highly water soluble. It is inhibitory to yeasts, moulds and bacteria, probably due to its impact on pH (Doores, 1993). It is used in beverages, hard candies, canned tomatoes and fruit pie fillings.
It is often found in unripe fruit and is also present in wine. Malic acid levels in soft drinks, fruit juices and wine need to be strictly controlled as too low or high levels may result in product deterioration.
Together with tartaric acid, malic acid makes up about 90% of the total acidity of wine. Malic acid is also used as flavoring agent in the sour confectionary sector. Similar as the other organic acids, malic acid has been found to be an effective agent for inactivating common food pathogens on fresh vegetables.
Malic acid is one of the key grape acids present in grape must. Indeed, alongside tartaric acid it represents up to 80% of its total acidity. It significantly influences the final organoleptic characteristics of wine.