Review on essential oils in citrus fruits

Citrus essential oils (EOs) are widely used as flavoring agents in food, pharmaceutical, cosmetical and chemical industries. For this reason, their demand is constantly increasing all over the world. Besides industrial applications, the abundance of EOs in the epicarp is particularly relevant for the quality of citrus fruit. In fact, these compounds represent a natural protection against postharvest deteriorations due to their remarkable antimicrobial, insecticidal and antioxidant activities. Several factors, including genotype, climatic conditions and cultural practices, can influence the assortment and accumulation of EOs in citrus peels. This review is focused on factors influencing variation ofthe EOs? composition during ripening and on the implications on postharvest quality of the fruit. Contents1. Introduction2. Essential Oils of Citrus Fruits (Table 1 occupies from page 3 to 21)3. Main Changes in the Essential Oils Content during Fruit Maturation4. Biological Properties as Related to Protection against Postharvest Deterioration5. The Role of Endophytic Fungi6. Conclusions? ConclusionIn recent years, citrus essential oils have gained great popularity for applicative?usage in the food and cosmetic as well as the pharmaceutical industries, which has been?technically refined by the availability of several kinds of microformulations. The?increasing demand underlines the opportunity to recycle citrus peels contained in wastes?from the food industry for their extraction. However, the raw material is?qualitatively highly heterogeneous as it is influenced by several factors including the natureand provenance of the fruit, genotype, soil type, climatic and cultural conditions. It has?been demonstrated that the chemical compositions of the citrus peels vary significantly?during ripening. For this reason, harvesting time is a critical parameter, especially because?EOs have an important role in the protection from postharvest fruit deteriorations. In fact,?EOs in the immature fruit stages have a higher effectiveness against pests and pathogens.?This evidence may be adaptatively interpreted with the necessity by the plant to protect?developing fruits; while in ripe fruits this need would no longer be relevant, considering?that they are destined either to be eaten by frugivorous animals or to fall to the ground?to allow seed dispersal. Adaptative factors may also regard the capacity of some?endophytic associates to directly synthesize these products, which contribute to shaping?their ecological role as defensive mutualists. Undoubtedly, this aptitude deserves more?in-depth assessments in view of a possible exploitation for improving postharvest quality. SourcesEssential Oils in Citrus Fruit Ripening and Postharvest QualityMaria Michela Salvatore, Rosario Nicoletti, and Anna AndolfiHorticulturae 2022, 8, 396.https://doi.org/10.3390/horticulturae8050396 Picture by?V2MShop