Atmospheric cold plasma-assisted extraction of basil (Ocimum basilicum) leaves bioactives for yogurt fortification: A food engineering approach

The study evaluated the effectiveness of dielectric barrier atmospheric cold plasma (DBD-ACP) as a sustainable, non-thermal pretreatment to enhance the extraction of bioactive compounds from basil leaves and improve the quality of fortified yogurt during refrigerated storage. A 10 g sample of basil powder was exposed to DBD-ACP for 60s, 90s, and 120 s. The plasma aqueous extraction efficiency was compared with ethanol extraction. The best plasma-treated extract was incorporated into yogurt, and enriched yogurt was assessed for microbiological, chemical, and sensory properties. Results illustrated that DBD-ACP pretreatment significantly increased total phenolic content (25.57 mg GAE/g), total flavonoid content (14.33 mg QE/g), and antioxidant activity (78.4% DPPH) after 120 s of exposure, along with elevated levels of eugenol and linalool. Engineering analysis demonstrated high efficiency, with specific energy input (900–1800 J/g), extraction yield (6.12–24.46%), system performance coefficient (0.022–0.037 g/J), and energy efficiency (0.0068–0.0136 mg/J) increasing with treatment time. Incorporating plasma-treated basil extracts (TY) into yogurt significantly reduced total viable counts (2.53–3.92 log CFU/g) and yeast/mold counts (1.09–3.12 log CFU/g), while maintaining a higher pH (4.48 ± 0.02) and lower titratable acidity (0.84 ± 0.02%). Sensory evaluations confirmed enhanced flavor, color, and overall acceptability, particularly in TY5 samples. Overall, DBD-ACP proved to be an energy-efficient, solvent-free technology that enhanced bioactive recovery and produced stability, offering a promising green approach for developing functional, clean-label dairy products.