Designing Sustainable Probiotic Almond Spreads through Ultrasound, Lactic Fermentation, and Microencapsulation: A New Approach to Functional Plant-Based Foods

Developing sustainable, functional plant-based foods is increasingly important. This study developed an almond-based spread enriched with Lacticaseibacillus casei ATCC 334 using ultrasonication, lactic fermentation, and microencapsulation. Ultrasound treatments at 40–80% amplitude for 5–10 min were assessed; the mild condition (40%, 5 min) reduced syneresis and enhanced the antioxidant activity of the almond extract. Four spreads were produced, and the formulation combining ultrasound treatment, fermentation, and spray-dried microencapsulated probiotic showed favorable physicochemical and probiotic stability characteristics. It exhibited suitable composition (moisture, 47.1%; fat, 29.9%; protein, 10.4%), controlled acidity (3.1%; pH 4.7), and a metabolite profile containing amino acids, polyols, and lipophilic antioxidants. The product displayed a firmness of 0.95 N and a stable gel structure for 21 days. Antioxidant capacity increased during storage, while probiotic viability remained above functional levels and persisted after simulated gastrointestinal digestion (≥6 Log CFU/g). These results demonstrate that integrating these technologies improves stability and probiotic performance in almond-based fermented spreads.