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

Abstract

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.

A Critical Review on Pulsed Electric Field: A Novel Technology for the Extraction of Phytoconstituents

“…Fruit and vegetable flesh or pulp is consumed while the other components, which are not mostly consumed, such as peel and seeds, contain a significant amount of various vital nutrients and phytochemicals [ 9 , 75 , 76 ]. For example, lemon, grapes, orange peels, avocado, jackfruit, longan, and mango seeds contain more than a 15% phenolic concentration, which is higher than those contained in fruit pulp [ 77 ].…”

“…Soxhlet, heat reflux, soaking, water percolation, maceration, magnetic stirrer, boiling, and grinding are the traditional practices used to obtain phytoconstituents but involve high solvent consumption, a long processing time, poor or low extraction yields, and few have thermal degradation risks. To overcome the limitations of these traditional technologies, numerous innovative non-thermal extraction techniques have been evaluated [ 8 , 9 ].…”

Sonication, a Potential Technique for Extraction of Phytoconstituents: A Systematic Review

“…In the food industry, ultrasound was used for the tenderization, curing and microbial inactivation of meats [18,19]. Moreover, it enhanced bioactive elements, β-glucan content, cereal, fruit and vegetable phenolics and cereal starch extraction [6,[20][21][22][23][24]. High-intensity ultrasound extraction methods increase quality and speed of a vast range of food components such as oils, flavourings, pigments and bioactive substances, including antioxidants and essential oils from aromatic plant material, such as basil, artemisia and lavender [25].…”

Heterocyclic Aromatic Amines in Meat: Formation, Isolation, Risk Assessment, and Inhibitory Effect of Plant Extracts

“…Products from natural sources have been used for centuries [ 26 , 27 ]. Plants, because of their phytochemical profile, have emerged as the best resource to fight against different disorders and diseases [ 28 , 29 ].…”