Broccolini (Brassica oleracea Italica × Alboglabra) is a hybrid of broccoli and kai-lan, Chinese broccoli. To date, no information is available on the extraction of flavonoids from Broccolini. In this study, an efficient ultrasonic-assisted extraction technique was developed to extract flavonoids from Broccolini leaves. The operating parameters were optimized using Box-Behnken design combined with response surface method. The analysis of variance showed that the response surface model fits very

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... well with the actual situation. Based on the response model, the optimal conditions were determined as follows: extraction temperature 60 o C, ethanol concentration 70% and solid to liquid ratio 1:27. Under the optimal conditions, the maximum response value of yield (11.96 mg/g dry weight) was consistent with the experimental value (11.95 mg/g dry weight), demonstrating that large amounts of flavonoids can be efficiently extracted from Broccolini leaves using ultrasonic-assisted method although the process needs further optimization along with the development of purification method for food applications.