Probiotic-fortified <i>Solanum lycopersicum</i> (tomato) juice: free or encapsulated <i>Lactobacillus plantarum</i> and <i>Lactobacillus</i> <i>delbrueckii</i>

Recent consumer perception of a nutritious diet improves demand for functional and safety products such as probiotics. The present research aims to investigate enriching Solanum lycopersicum (tomato) juice, including free and encapsulated probiotic bacteria. Initially, physicochemical attributes of encapsulations were evaluated. Then tomato juice samples, including a control without bacteria, free or encapsulated Lactobacillus plantarum (L. plantarum, T1 and T2), Lactobacillus delbrueckii (L. delbrueckii, T3 and T4), and a mixture (T5 and T6), were prepared over 28 days of shelf life. Several assays were performed, such as pH, lycopene, turbidity, stability, antioxidant, probiotic viability, sensory, and structure. Physicochemical functions of encapsulation illustrated that the results were in the suitable range. The pH of all treatments declined, and free L. plantarum demonstrated a greater effect on reduction. The control and encapsulated L. plantarum samples exhibited the lowest lycopene, ranging from 0.64 to 0.35 μL/mL, while the highest ranged from 0.64 to 0.50 μL/mL during the shelf life. Encapsulated dual bacteria indicated higher turbidity, stability, and antioxidant features compared to the control throughout shelf life. The control maintained greater transparency than others, and microbial analysis indicated that probiotic populations were elevated until the 14th day and then reduced. The encapsulated dual-bacteria illustrated the maximum viability and sensory, while the control had the minimum ratings. Morphological analysis confirmed a homogeneous structure for encapsulated bacteria. Overall results depicted that treatments containing encapsulated bacteria are considered the preferred option to promote nutritious juice.