Fourier transform infrared spectroscopy (FTIR) analysis, chlorophyll content and antioxidant properties of native and defatted foliage of green leafy vegetables

FTIR analysis for five selected green leafy vegetables
(GLVs) viz., Hibiscus cannabinus L., (kenaf), H. sabdariffa
L., (roselle), Basella alba L., (vine spinach), B. rubra L.
(malabar spinach) and Rumex vesicarius L., (sorrel) confirmed
the presence of free alcohol, intermolecular bonded alcohol,
intramolecular bonded alcohol, alkane, aromatic compounds,
imine or oxime or ketone or alkene, phenol and amine
stretching. The chlorophyll content was higher in native leaves
of B. alba (2.96 g/kg) than defatted samples (1.11 g/kg). Total
phenolic content (TPC) in H. sabdariffa native methanol extractives
is more (17.6 g/kg) than defatted leaves (9.67 g/kg).
Native B. rubra methanol extractives exhibited highest total
flavonoid content (TFC) (21.59 g/kg), while that of
R. vesicarius was lowest (3.21 g/kg). In general, antioxidant
activities showed a significant reduction in retention of antioxidants
in both native and defatted GLVs samples of ethanol and
methanol extractives.Methanol extractives showed significantly
stronger antioxidant activity probably due to greater solubility
of phenolics and destruction of cellular components.