Investigations of the Chemical Composition and Aromatic Properties of Peel Essential Oils throughout the Complete Phase of Fruit Development for Two Cultivars of Sweet Orange (Citrus sinensis (L.) Osb.)

Abstract

The peel essential oil (PEO) of sweet orange is used for flavoring liquors or foods and in the perfumery and cosmetics industry. The fruit maturity stage can modify the essential oil composition and aromatic properties, but little information is available on the evolution of PEO during the entire time set of fruit development. In this study, the yield, chemical composition and aromatic profile over the three phases of orange development were monitored. Four fruit traits (peel color, weight, acidity and sweetness) were recorded to characterize fruit development. Fruits of two sweet orange cultivars were sampled every two weeks from June to May of the next year. PEO was obtained by hydrodistillation and analyzed by gas chromatography coupled with a flame ionization detector (GC-FID). Compounds were identified with GC coupled with mass spectrometry (GC/MS). Ten expert panelists using the descriptor intensity method described the aromatic profile of PEO samples. The PEO composition was richer in oxygenated compounds at early fruit development stages, with an aromatic profile presenting greener notes. During fruit growth (Phases I and II), limonene’s proportion increased considerably as a few aliphatic aldehydes brought the characteristic of orange aroma. During fruit maturation (from November to March), the PEO composition and aromatic profile were relatively stable. Later, some modifications were observed. Regardless of the fruit development stage, the two sweet oranges presented distinct PEO compositions and aromatic profiles. These results constitute a temporal reference for the chemical and aromatic evolution of sweet orange PEO in the fruit development process under Mediterranean conditions. During the first two phases of fruit development, many changes occur in the PEO composition and aroma, suggesting that their exploitation could create new products.

Inheritance and Quantitative Trait Loci Mapping of Aromatic Compounds from Clementine (Citrus × clementina Hort. ex Tan.) and Sweet Orange (C. × sinensis (L.) Osb.) Fruit Essential Oils

“…However, in the clementine × orange progeny, some individuals are clearly different, with relatively low levels of limonene and high levels of linalool, sabinene, neral and geranial. These compounds present in significant amounts have been identified as markers of fruit immaturity in orange [ 48 ]. It is therefore possible that the fruits of these genotypes mature later than those of other hybrids from this cross.…”

Effects of Orange Peel Extract on Laccase Activity and Gene Expression in Trametes versicolor

“…Indeed, orange peels are rich in aromatic compounds, including free phenolic compounds from two main classes: flavonones and flavones. Moreover, large amounts of phytochemicals, such as carotenoids, flavonoids, aldehydes, esters, terpenes, alcohols and ketones, are also present in orange peels [48,49]. For example, limonene constitutes around 75% of the total extractable essential oils [46] and is therefore likely to be involved in influencing In addition to LCC2 and LCC3, the most pronounced upregulation in response to the presence of OPE was observed for LCC5, encoding TvLac5, with a log 2 value of 8.23 corresponding to a fold-ratio value of 300.…”

Chemical Variability, Antioxidant and Larvicidal Efficacy of EOs from Citrus sinensis (L.) Osbeck Peel, Leaf, and Flower

“…In addition to nutritional values, citrus fruits are enriched in various bioactive components such as flavonoids, phenols, limonoids, EOs, vitamin C, and carotenoids associated with health advantages [3]. Citrus is the principal source of EOs used from ancient times [4], and approximately 60% of citrus oils are produced from the peel of sweet oranges [5].…”