A novel, green environment-friendly cloud point extraction of polyphenols from pomegranate peels: a comparative assessment with ultrasound and microwave-assisted extraction

Abstract

ABSTRACT Pomegranate peel is a potential source of polyphenols, antioxidants, pectin, organic acids. Cloud point extraction (CPE) process parameters were optimized for efficient separation of polyphenols. Maximum extraction was obtained at 1:70 solid: solvent ratio, 8% (v/v) Triton X-114 at 55°C, pH 4.5 with 14% NaCl for 30 minutes. Ultrasound assisted CPE showed maximum yield of total phenolic content (TPC; 96.28 mg GAE/g) and total flavonoids content (TFC; 12.27 mg QE/g) with 94.48% antioxidant activity (AA) to that of conventional, ultrasound and microwave-assisted CPE. These extractives can be labeled as green and may be used in food or dietary applications. Abbreviations: CPE: Cloud point extraction; AA: Antioxidant activity; TPC: Total polyphenol content; TFC: Total flavonoid content; CPT: Cloud point temperature; CMC: Critical micellar concentration; OVAT: One variable at a time; GAE: Gallic acid equivalent; QE: Quercetin equivalent; HLB: Hydrophilic lipophilic balance