Phytochemical and Antimicrobial Potentials of Aqueous Leaves Extracts of Helianthus annuus (Sunflower): A Natural Preservative in Food Industry

Helianthus annuus (sunflower) is an important plant that belongs to the family Asteraceae and usually used as oil in the food industry. This study investigates the phytochemical and antimicrobial potentials of aqueous leaf extracts from Helianthus annuus (AqHa). The H. annuus leaves were collected from botanical section of Ajayi Crowther University, Oyo and were taken to the laboratory and processed into aqueous extract using standard method. The Aqueous leaf extracts from Helianthus annuus (AqHa) were assessed for phytochemical attributes, Fourier transform infrared Spectroscopy (FTIR), antioxidant activity and antimicrobial potential against food pathogens using standard procedures. Phytochemical analysis of the assessed extracts revealed the presence of some plant metabolites including flavonoids, steroid, tannins and saponins while FTIR showed the presence of some key functional groups such as O-H stretch, H-bonded, O-H stretch, H-bonded, Methylene C-H stretch, Methyne C-H stretch and C=C Conjugated bonds. The peak at 2355.00 cm1 and 1735.60 cm1 were related to stretch vibration of Methylene C-H and C=C, respectively both denoting the presence of fat while the highest peak (3759.57 cm-1) was related to hydroxyl group. AqHa had the highest zone of inhibition (13 mm) against Staphylococcus aureus while the least (7 mm) inhibition was on Staphylococcus spp. The highest antioxidant activity was evaluated as Hydrogen peroxide scavenging assay (56 and 87%) and reducing power scavenging assay (49% and 83%). Aqueous leaf extracts from Helianthus annuus (AqHa) contains phytochemical compounds, had antioxidant activity and antimicrobial potentials on food pathogens, and could be used as an alternative in the development of plant based antimicrobials or as preservatives in food industries.