Antioxidant and antimicrobial prospects of Colocasia esculenta stolon: a phytochemical perspective

The cultivation of Colocasia esculenta, commonly referred to as taro, is largely focused on its corms and leaves, but the health benefits of its stolons remain underexplored. This research explores the proximate composition, phytochemical content, antioxidant capacity, and antimicrobial properties of C. esculenta stolons. The proximate analysis indicated a high moisture content (81%) along with notable levels of ash (6.2%), fibre (5.9%), protein (1.45%), fat (2.1%), and carbohydrates (3.35%). Phytochemical screening revealed the presence of various bioactive compounds, including glycosides, flavonoids, terpenes, phenols, quinones, steroids, and saponins. Among the solvents tested, methanol proved to be more effective than water in extracting most of these compounds. Antioxidant assays showed significant amounts of phenolics (150.5 mg GAE/100 g), flavonoids (80.25 mg QE/100 g), β-carotene (0.65 mg/100 g), and ascorbic acid (57.6 mg/100 g), which contribute to a substantial DPPH scavenging activity of 66.85%. The HPLC analysis using PDA detector uncovered essential bioactive constituents such as (-) epicatechin (10.99 mg/100 g), catechin hydrate (14.18 mg/100 g), and trans-ferulic acid (26.80 mg/100 g), highlighting their potential health benefits. Antimicrobial tests demonstrated the extract's effectiveness against Gram-positive bacteria, such as Staphylococcus spp. (15.56 ± 1.30 mm inhibition zone), and fungi, like Aspergillus flavus (12.51 ± 0.25 mm inhibition zone). Based on these findings, C. esculenta stolons appear to be a valuable natural source of antioxidants and dietary fibre, with notable nutritional and medicinal benefits and effective antimicrobial activity against both bacterial and fungal pathogens.