Application of nanoencapsulated Rosmarinus officinalis extract as a natural additive in probiotic tahini cake

This study aimed to examine the nanoencapsulation of Rosmarinus officinalis extract (ROE) using different ratios of gum arabic (GA) to maltodextrin (0:100, 25:75, 50:50, 75:25, 100:0) and its influence on the quality properties of probiotic tahini cake. Elevation of the concentration of GA in the wall formulations increased antioxidant activity and lowered release rate as well as zeta potential. FTIR indicated that the presence of higher amounts of maltodextrin in the nanocapsules made the structure more hydrophilic and enhanced hydrogen bonding between the capsule and the extract compounds. The nanoencapsulated ROE with a 75:25 ratio of GA to maltodextrin, which had the highest encapsulation efficiency and low release, was selected for enriching the cake. Various concentrations (2.5%, 5%, and 7.5%) of free and nanoencapsulated ROE were used in the formulation of probiotic cake. The lowest free fatty acid content and peroxide value were observed in the cake containing 7.5% nanoencapsulated ROE. The sample containing 7.5% nanoencapsulated ROE presented the highest antioxidant activity, the lowest mold and yeast counts, and the highest probiotic counts. ROE improved the sensory and textural properties of the samples. Considering the sensory, physicochemical, textural, microbiological, and functional properties, the cake containing 5% nanoencapsulated ROE was selected as the best sample. • Rosmarinus officinalis extract was nanoencapsulated with gum arabic and maltodextrin. • The highest encapsulation efficiency was obtained in the ratio of 75:25 GA: MD. • Increasing the concentration of gum arabic decreased the release rate. • The nanoencapsulated ROE increased the antioxidant activity in tahini cake. • The nanoencapsulated ROE improved the survival of probiotic bacteria in tahini cake. • Adding ROE positively affected the sensory characteristics of probiotic tahini cake.