The Effect of Proniosomal Hydroxytyrosol Enriched Extract Added During Pre- and Post-Fermentation of Yoghurt Production

Why It Matters

Encapsulating antioxidant‑rich olive extracts improves yoghurt’s water‑holding and functional profile without compromising taste, offering dairy producers a scalable route to value‑added, health‑focused products.

Key Takeaways

• Proniosomal OLBE reduced yoghurt syneresis by up to 4 %
• pH and acidity shifts were minor, remaining within typical yoghurt range
• Texture firmness decreased as proniosome concentration increased
• Color brightness (L*) stayed statistically unchanged versus control

Pulse Analysis

The dairy sector is increasingly turning to functional ingredients that boost nutritional value while preserving product quality. Hydroxytyrosol, a potent antioxidant found in olive leaf extracts, offers health benefits but is prone to degradation in the acidic, enzymatic environment of yoghurt. Encapsulation technologies such as proniosomes protect bioactive compounds, control release, and improve solubility, making them attractive for fortifying fermented foods without altering their sensory attributes.

In the recent study, a proniosomal formulation containing 81 % encapsulated hydroxytyrosol‑enriched olive leaf brine extract was introduced at two critical stages of yoghurt production: pre‑fermentation, where the powder mixes with heated milk before starter inoculation, and post‑fermentation, where it is blended into the finished gel. Across both approaches, the fortified yoghurts displayed a consistent reduction in syneresis—down to 33 % from the control’s higher rate—indicating enhanced water‑holding capacity. While pH and total acidity showed statistically significant changes, they remained within the standard yoghurt range (pH ≈ 4.3‑4.4). Textural analysis revealed a dose‑dependent softening, yet sensory panels rated overall acceptability on par with plain yoghurt, suggesting the changes are not perceptible to consumers.

These findings have clear commercial implications. Dairy manufacturers can leverage proniosomal delivery to embed antioxidant‑rich extracts, differentiating their product lines in a crowded market focused on health and wellness. The technology aligns with clean‑label trends, as maltodextrin and natural surfactants are widely accepted. Moreover, the modest impact on acidity and color simplifies regulatory compliance and shelf‑life forecasting. As consumer demand for functional dairy grows, proniosomal fortification offers a viable pathway to enhance nutritional profiles while maintaining the texture and taste that define successful yoghurt brands.