Inhibition of Bacterial growth, mineral, proximate and vitamin contents of a syrup prepared from Vitex doniana fruits

This study aims to investigate the in-vitro antibacterial activity, mineral and vitamin compositions, proximate composition, and organoleptic properties of a syrup derived from Vitex doniana fruits.

V. doniana fruits were mashed, mixed with water, strained, and boiled to thicken the filtrate.  The syrup’s antibacterial activity was tested on 7 clinical and 6 American Type Culture Collection (ATCC) isolates using well-in-agar diffusion method on Mueller Hinton agar. The fruit juice underwent mineral analysis using atomic spectroscopy and mass spectrometry. Proximate composition, vitamin, and organoleptic properties of a syrup were evaluated.

Clinical Escherichia coli 0157:H7 and Staphylococcus aureus isolates were susceptible to the syrup, with inhibition zone of 25 mm each while S. aureus ATCC 25923had the highest susceptibility with a 33 mm inhibition zone. The syrup showed varying minimum inhibitory concentrations (12.5-50 mg/ml) and minimum bactericidal concentrations (25-150 mg/ml) against tested bacteria. The syrup contained 18.4±0.36 mg calcium, 36.92±0.14 mg magnesium, 3.21±0.30 mg iron, 4.80±0.24 mg sodium, and 43.56±1.05 mg potassium as mineral composition per 100 g. Although the prepared syrup had higher calcium, magnesium and iron values prepared to the commercial sample, there was no significant difference between the two. Proximate composition analysis revealed moisture content was measured at 20.83±1.08% moisture content, pH=4.76, 0.20±0.01% crude fiber, 2.40±0.35% crude protein, 3.18±1.12% ash, 0.62±0.24% crude fat, and 76.70±0.16% carbohydrate levels in the syrup. Significant difference was only found in ash and carbohydrate values, with the prepared sample showing higher levels. The syrup exhibited higher vitamin content, including vitamin C, B1, B2, B6 and A, compared to the commercial sample. In terms of organoleptic properties, the prepared syrup scored slightly better in taste, flavor, and overall acceptability (0.18%) compared to the commercial product.

Based on these finding, the syrup derived from V doniana shows potential as a nutrient food product with antimicrobial properties. It could be used in healthcare, industrial applications (such as preservatives or sweeteners), and as a base for pharmaceutical formulations. Furthermore, the syrup may find applications in the confectionery, bakery industries, and traditional medicine.