Natural colourant from Saccharum officinarum L. peels: An assessment of its antioxidant and antibacterial activities and its stability as colourant in paracetamol syrup

A colorant is a dye that imparts colour to food, drinks, pharmaceuticals and cosmetics.The synthetic colourants have been used frequently for this purpose and have been reported to have adverse effects on human health.Saccharum officinarum L. (sugarcane) belongs to the Poaceae family and its purple-brownish peel is considered as potential source of colourant.The aim of this study was to evaluate the stability of the peel colourant in paracetamol syrup and investigate its phytochemical, antioxidant and antibacterial activities.The powder peel was evaluated for macroscopic, physicochemical and phytochemical properties.The colorant was extracted by maceration in methanol.The organoleptic evaluation revealed purple-brownish colour, odourless and tasteless powder.The moisture content, total ash, acid insoluble ash, alcohol and water-soluble extractive values were 0.867 0.288%, 3.01 0.054%, 1.37 0.02%, 7.58 0.29% and 8.35 1.46% respectively.The phytochemical screening has revealed the presence of saponins, flavonoids, tannins, glycosides, steroids and triterpenoids.The colourant demonstrated antioxidant activity in the DPPH and H2O2 assays with IC50 values of 4.456 and 2.864 g/mL respectively.The zone of inhibition of growth between 15 to 60 mg/mL was found to be 1-7 mm in Escherichia coli (Gramnegative) and Streptococcus pneumoniae (Gram-positive).The ciprofloxacin (standard) at 2 mg/mL had a zone of inhibition of 29-32 mm in the test organisms.The study has revealed that the stability of the colourant in the paracetamol syrup formulation and provided preliminary evidence for the presence of phytochemicals that possess antibacterial and antioxidant activities in the extracted natural colorant.