Micromorphological and nutritional attributes of two varieties of Vernonia amagdalina del. domesticated in Delta State

Abstract

This study examined the potential of two Vernonia amygdalina varieties (bitter and non-bitter) as sources of nutrients and medicinal compounds. Micromorphological analysis revealed variations in stomata size (bitter: 1.57±0.20 μm; non-bitter: 1.49±0.42 μm), index (bitter: 1.20±0.60%; non-bitter: 2.30±0.21%), and trichome index (bitter: 0.55±0.36%; non-bitter: 0.90±0.19%) between the varieties, while stomata type and anticlinal wall patterns were similar. Both varieties were rich in minerals, with bitter varieties containing higher levels of sodium (7.27±0.43 mg/g), potassium (17.07±0.45 mg/g), phosphorus (3.15±0.41 mg/g), iron (0.65±0.02 mg/g), zinc (0.15±0.03 mg/g), and copper (0.16±0.04 mg/g) compared to non-bitter varieties. Proximate composition analysis showed higher levels of crude fiber (1.76±0.50%), crude protein (21.07±0.30%), and carbohydrate (23.33±0.82%) in non-bitter varieties, while bitter varieties had higher levels of moisture (50.01±0.40%), crude ash (7.95±0.56%), and crude fat (2.15±0.20%). Phytochemical analysis revealed higher levels of tannin (0.13±0.85%), saponin (0.08±0.02%), and flavonoid (0.22±0.09%) in non-bitter varieties, while alkaloid levels (1.26±0.27%) were higher in bitter varieties. These findings suggest that both Vernonia amygdalina varieties are valuable sources of nutrients and phytochemicals, with potential applications in food and medicine.