THIS INVENTION relates to coatings and films. It relates in particular to a composition from which a coating or film can be formed, and to a coating or film when formed from such a composition. According to a first aspect of the invention, there is provided a composition from which a coating or film can be formed, the composition comprising at least one prolamin protein; as a plasticizer, gluconic acid and/or a gluconic acid derivative; and a solvent for the protein and the plasticizer, so that the composition is in the form of a solution. It is to be appreciated that when the various components of the composition are food grade, a coating or film obtained from the composition can safely be ingested. Furthermore, it is believed that coatings obtained from the composition will have particular application to edible products or foodstuffs, such as fruit and vegetables, or other ingestible products, such as solid pharmaceutical products, eg pills or tablets, without imparting offensive tastes, eg sour tastes, to the products. Prolamin proteins are simple proteins found in plants, and typically contain hydrophobic amino acids such as leucine, proline and alanine, as well as glutamine. In particular, the prolamin protein may be a grain or cereal protein such as zein, which is found in maize, or kafirin found in sorghum; however, kafirin is preferred. There are two primary reasons why kafirin is the preferred prolamin protein. Overall, it is more hydrophobic than other prolamins such as wheat gliadin and maize zein (Duodu, KG et al. Journal of Cereal Science 38:117-131). Hence, it should be a better moisture barrier. It is also more cross-linked than zein (Duodu, KG et al. Journal of Cereal Science 38:117- 131). especially after having been subjected to thermal, treatment, as is the case in film or coating mai