Bioactive compounds and properties of chinotto (citrus myrtfolia Raf.) at different ripening stages

Abstract

Citrus myrtifolia Raf. (chinotto) is a citrus fruit which originates from a mutation of Citrus aurantium (sour orange). This fruit has a small size and looks like a ping-pong. In Italy, The plant is cultivated in Calabria, Sicily and Liguria. The fruit of chinotto is widely used in food industry. Concentrated chinotto juice is a key ingredient in the production of soft drinks and liqueurs, whereas the whole fruit is used in the confectionery industry. However, despite its industrial applications, chinotto is among the least studied citrus fruit, with only a few reports present in the literature. Here, we studied bioactive compounds contained in all parts of chinotto fruit. We also investigated the changes of those bioactive compounds during maturation and different area cultivation. First, the oil content from the seeds were analyzed, in order to assess the fatty acid profiles. After that, the methanolic extracts and DMF extracts of the defatted seeds and pulps were analyzed for their total phenolic contents (TPC) and antioxidant capacities. The results showed that all those extracts had the ability to scavenge both DPPH and ABTS radicals. TPC value is highly dependent on the level of fruit maturity. Moreover, we also isolated the pectin and β-glucan from chinotto seeds and pulps, and characterized them using FT-IR, in order to provide the valuable information about the new alternative sources of pectin and β-glucan. Essential oils were extracted from the peels. The effects of maturation on the composition in volatile compounds of those essential oils were evaluated. After that, the potential antioxidant and anti-inflammatory properties of these fractions were tested. Our finding showed that essential oil obtained from semiripe chinotto peels effectively modulates inflammation in vitro and could, therefore, represent a potential attractive source of bioactive compounds for food, cosmetic, or pharmaceutical applications