Antimicrobial activity, phytochemical profile and trace minerals of black mulberry (Morus nigra L.) fresh juice

Abstract

In the present work, the fresh juice of black mulberry (Morus nigra) was tested for antimicrobial activity against various pathogenic microorganisms. Total antioxidant contents, total phenolic contents, total anthocyanins, trace minerals, total acid contents, total solids and ascorbic acid content were also evaluated. The results showed good antimicrobial activity both for Gram- positive and Gram-negative bacteria, with highest zones of inhibition for Bacillus spizizenii (19.68 mm, Gram-positive) and Pseudomonas aeruginosa (19.87 mm, Gram-negative). The black mulberry juice was rich in ascorbic acid (23.45 mg/100 g), had low overall acid content (1.60 %) and had 19% total soluble solids. The average total anthocyanins and total phenolic contents of black mulberry juice were 769 µg/g of cyanidin 3-glucoside equivalent (Cy 3-gly) per gram and 2050 µg of gallic acid equivalent (GAE) per gram of fresh juice. The average antioxidant activity (Trolox equivalent, TE) of fresh juice was 14.00 µmol/g according to a FRAP assay and 20.10µmol/g according to a DPPH assay. The fresh juice was also rich in a variety of trace minerals.

Keywords Minerlas, Black mulberry, Antioxidant