Valorization of persimmon fruit (Diospyrus kaki) waste as a source of carotenoids

The production and commercialization of persimmon fruits generate waste that is often not reused and wrongly discarded. These residues are rich in bioactive compounds such as carotenoids, which can be recovered for later use as natural colourants. Ultrasound-assisted extraction (UAE) has been used to recover bioactive compounds from plant materials, considerably improving the extraction yield when compared to conventional extraction. This work aimed to evaluate the UAE of carotenoids from persimmon residues, considering three process variables: types of solvent (ethyl acetate and sunflower oil), ultrasound power (80-220 W), and extraction time (11 to 329 s). The obtained extracts were evaluated for colour (parameters L, a*, and b*) and carotenoid content. The ultrasound process resulted in a carotenoid content three times higher than conventional extraction. Ethyl acetate promoted a carotenoid extraction 50% higher (1887.04 µg/100 g of extract) than sunflower oil (930.85 µg/100 g of extract). The highest concentration was obtained with ethyl acetate when the ultrasound was applied at 150 W for 5.5 min. The extracts with the most intense yellow colour were those with the highest concentration of carotenoids and obtained by UAE with ethyl acetate, with good potential to be used as a natural colourant in the food industry.