Extraction of Polyphenols from Apple and Pomegranate Peels Employing Different Extraction Techniques for the Development of Functional Date Bars

Polyphenols are natural antioxidants and play a very vital role in inhibition of oxidative stress as induced by free radicals in the body. Apple and pomegranate peels are significant agro-industrial wastes. The waste could be utilized to extract polyphenols for processing various functional foods and nutraceuticals. An investigation was executed for extraction of polyphenols from apple and pomegranate peels by sonication and maceration. Three different polar solvents: methanol, ethanol, and acetone were used in the study at two different concentrations (50% and 75%). Yield (%), total polyphenolic content (TPC), total flavonoid content (TFC), and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay were performed. The extracts were then utilized in processing functional date bars with 2% and 3% concentrations. The results from the current study articulated that extraction from sonication yields higher quantity of polyphenols than that of maceration technique. The highest polyphenols were extracted at acetone 75% (44.71 mg GAE/g) in apple peel and at methanol 50% (72.21 mg GAE/g) in pomegranate peel. The results also revealed that pomegranate peel has higher polyphenols and greater radical scavenging activity as compared to apple peel. It was concluded that apple and pomegranate peel polyphenolic extract fortified date bars could be utilized as a preventive therapeutic agent against certain oxidative stress degenerative diseases.