A sustainable source of phytochemicals and potential antibacterial applications

The increase in the world’s population is producing waste proportionately, which plays a crucial role in air, water, and soil pollution and contamination. Therefore, the present study focuses on valorizing agro-waste by extracting phytochemicals and determining phenolic content, total flavonoid, and total antioxidant capacity using gallic acid, rutin, and ascorbic acid as standard. Further, pectin extraction from agro-wastes by traditional and microwave-assisted methods was compared. Of the various agro-wastes studied, pomegranate peel and maple leaf illustrated higher flavonoid (314.25 ± 3.30 and 350.26 ± 3.48 mg rutin equivalent/100 g in methanol extract), total phenolic content (48.36 ± 2.33 and 47.96 ± 1.67 mg gallic acid equivalent/100 g in methanol extract), and total antioxidant capacity (55.03 ± 2.56 and 50.45 ± 1.02 µg ascorbic acid equivalent/g dry weight in aqueous extract). Different solvents used in extraction showed distinct potentials for evaluating total phenolic content, total flavonoid, and antioxidant capacity. Also, the antibacterial potency of the aqueous extract of pomegranate peel exhibited the highest inhibition zone against Cellulomonas sp. (S-10) and Bacillus sp. (S-17) among the locally isolated pectinase-producing bacteria. At the same time, pumpkin pulp + seeds did not show any inhibition. Besides, the study revealed higher pectin yield from pumpkin pulp + seeds followed by orange peel, banana peel, pomegranate peel, and others.

This study supports different agro-wastes as potential low-cost resources for the sustainable production of phytochemicals. In addition, those agro-wastes exhibited antibacterial potency and can be used in the pharmaceutical industries. Therefore, this study aims to decrease agricultural waste by utilizing them in producing value-added products, which ultimately helps sustainable economic development and pollution control.