Evaluation of physicochemical properties, nutraceuticals composition, antioxidant, antibacterial and antifungal potential of waste amla seed coat (Phyllanthus emblica, variety Neelam)

In the present study Amla seed coat powder was evaluated for its physicochemical parameters (water retention and water swelling capacity), nutraceutical composition (mineral and phytochemical composition) antioxidant (only DPPH method) and antibacterial [Burkholderia spp. Pseudomonas aeuroginosa (KF853103.3), Klebsiella spp. (KF424316.1)] and antifungal (Fusarium oxysporum) potential. Water retention and water swelling capacity of the amla seed coat powder were found to be 5.841 g/g and 8.96 mL/g of dry weight (DW). Seed coat contained a sufficient amount of minerals. Different extracts of amla seed coat were prepared by four extraction procedures (maceration (MM), orbital shaking (OSM), ultrasonication assisted extraction (UAEM) and Soxhlet extraction method (SEM)) using different solvents (petroleum ether (PEE), isopropyl alcohol (IAE), butanol (BUE), ethyl acetate (EAE) and acetone (AE)). All the extracts were found to contain different phytochemicals. SEM was found to be the best method giving maximum total phenolic and flavonoid content in BUE of amla seed coat with values 12.81 mg gallic acid equivalent (GAE)/g DW and 10.37 quercetin equivalent (QE)/g DW. Further, it has been found that in the antibacterial and antifungal analysis butanol extract has outperformed the results shown by other extracts. Correlation analysis shows positive correlation between total polyphenolic content (TPC), total flavonoid content (TFC) and various studied activities. Graphic abstract