Optimizing extraction of berberine and antioxidant compounds from barberry by maceration and pulsed electric field-assisted methods

Abstract

BACKGROUND: Barberry is a valuable plant, which is useful in the treatment of different diseases. There are valuable compounds in different parts of barberry that are pruned per year and discarded as waste. OBJECTIVE: In this study, the amount of berberine, phenolic compounds and antioxidant activity of barberry fruits, leaves, and stems of different barberry species (B.integerrima and B.thunbergii) were investigated. METHODS: Central composite design of response surface methodology (RSM) were used in this study to investigate the extraction variables (time: 2–24 h, temperature: 24–70°C and ethanol concentration: 50–90%) in the extraction of berberine from the stem of B.integrrima. The responses used as criteria were the amount of berberine, scavenging radical DPPH, and polyphenol. Also, pulsed electric field-assisted (PEF) was applied as a pretreatment (Pulse strengths of 250, 1000 and 1250 Vcm–1; Pulse numbers (n) of 50 and 100; frequency (f) of 1 Hz) and then the extraction was conducted in optimum condition. PEF increased significantly the amount of berberine. RESULTS: The stem of B.integrrima had the most amounts of antioxidant activity and berberine content, and it was selected for more investigation. The optimum condition in the maceration method was: 90% of ethanol, 70°C, and 3.36 h (141.6 min). According to the result of PEF method, the best condition for extraction of berberine from barberry stems was 1000 Vcm–1 and n = 100. CONCLUSIONS: The results demonstrated that the extract of B.integrrima stem is a good source of berberine, antioxidant, and has the potential to be applied in various industries.