Valuation of Citrus reticulata (kinnow) peel for the extraction of lutein using ultrasonication technique

Citrus reticulata (kinnow) peel is a good source of carotenoids which can be extracted using ultrasound-assisted extraction (UAE). The present study was conducted to optimize the process parameters for the extraction of lutein using UAE method with methanolic solution of potassium hydroxide as the extractant to obtain its maximum yield. The obtained extract was used for the determination of lutein yield using high-pressure liquid chromatography (HPLC). The optimized values of process parameters in the current investigation were 6.16 mL/g solvent/solid ratio, 43.14 °C temperature, 32.88% amplitude and time duration of 33.71 min, which resulted in highest lutein yield of 29.70 μg/g. The results of this study showed that UAE system has the ability to replace the conventional techniques for extraction of lutein from citrus peels. Moreover, the extracted lutein from citrus peels can be further used as an antioxidant and colouring agent in various food applications.