Improving bioavailability of pomegranate peel polyphenols by forming an inclusion complex with β-cyclodextrin (β-CD)

Due to the use of organic solvents is associated with environmental pollution, toxicological and safety concerns, alternative extraction methods have been investigated. In this study, the efficacy of application of β-Cyclodextrin (β-CD) and ultrasound-assisted extraction (UAE) as an eco-friendly, cost-effective and safe method for extraction of bioactive compounds from pomegranate peel compared to the aqueous extraction method was studied. The response surface method (RSM) was used to optimize extraction conditions. Designed experiments were done based on the Box-Behnken design with three independent variables, including temperature (30, 50 and 70 °C), time (10, 25 and 40 min) and concentration of β-CD solution (0, 0.9 and 1.8 %). The optimum extracting temperature and time and β-CD concentration were 55.7°C, 15.38 min, 1.8% respectively. In the optimum condition, the following characteristics of extracted bioactive compounds were obtained: Non-flavonoid phenols 75.77 (mgGAE/gDW( and extraction efficiency was 42.81%. Inclusion complex formation was confirmed by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) and SEM. As a result of this study, aqueous β-CD and UAE as a safe method can be replaced with other extraction methods to extract compounds with high nutritional value.