Shelf life prolongation of fruit juices through essential oils and homogenization: a review

Codex Alimentarius defines juice as “the fermentable but unfermented juice, intended for direct consumption, obtained by the mechanical process from sound, ripe fruits, preserved exclusively by physical means. The juice must have the characteristic colour, flavour and taste typical of the fruit from which it comes, it may be turbid or clear. The juice may have been concentrated and later reconstituted with water suitable for the purpose of maintaining the essential composition and quality factors of the juice. The addition of sugars or acids can be permitted but must be endorsed in the individual standard” [1]. Juices may be prepared from nearly all fruits, if desired; the most common ones include pineapple, orange, grapefruit, mango and passion fruit. Nevertheless, any fruits (e.g. banana, fig) can be easily pureed, but it is more expensive to produce a clear juice from the pulp. Generally juice is classified as puree, when the resulting consistency is a fluid that pours very slowly, or pulp when it pours even more slowly. Juices can be concentrated for preservation, handling and storage and then reconstituted before consumption. Nectars are made from fruit juices, to which water and sugar have been added; they contain a proscribed minimum of juice, ranging from 25 to 50%. Table 1 reports the classification of different types of drink made from fruits. Flow chart for juice production is simple; a generalized scheme is reported in Appendix I.