Study on the Effect of Ficus exasperata Aqueous Leaf Extract on the Rate of Lactic Acid Formation of Fermented Milk

Background and Objective: The utilization of medicinal plant extracts, such as Ficus exasperata, in yoghurt production offers a novel avenue for creating functional dairy products with augmented nutritional and medicinal attributes. This study aimed to elucidate the fermentation kinetics and physicochemical characteristics of yoghurt fortified with Ficus exasperata leaf extract. Materials and Methods: Fermentation progress was monitored by measuring pH and titratable acidity (TA (%)) over a 12 hrs period at 43°C for yoghurt samples labeled Yc (control) and Y1 (fortified). Proximate composition analysis encompassing moisture content, total solid content, specific gravity, ash content and protein content was conducted to evaluate the impact of fortification on nutritional parameters. Furthermore, the kinetics of lactic acid formation during fermentation were assessed using a differential method to discern reaction order and rate constant. Results: The prolonged fermentation time for fortified yoghurt samples (Y1, Y2 and Y3) compared to the control (Yc). Lactic acid formation followed a fractional order kinetics, suggesting intricate biochemical processes during fermentation. Physicochemical analysis revealed variations in pH, titratable acidity, moisture content, total solids, ash content, protein content and specific gravity among yoghurt variants. Additionally, the pH stability of all yoghurt samples was monitored for eight days. Conclusion: These findings underscore the potential of Ficus exasperata fortified yoghurt in offering enhanced nutritional value and bioactive properties, aligning with consumer preferences for healthier dietary options.