Design and fabrication of tryptophan loaded double nano-emulsion and its application in functional yoghurt

Abstract

stract: Introduction: Nutrition plays a fundamental role in maintaining human health, and amino acids, including tryptophan, hold special significance due to their effects on physiological processes such as the production of serotonin and melatonin. The use of tryptophan as dietary supplements faces challenges, such as the development of a bitter taste and the possibility of oxidation. The production of emulgels and double emulsions can be proposed as innovative solutions to address these issues. This study investigates the fortification of yogurt using double nanoemulsions containing tryptophan. Objective: The aim of this research is to design and develop double nanoemulsions (water-in-oil-in-water) containing tryptophan and to evaluate their application in the formulation of functional yogurt. Specifically, the study focuses on assessing the physical and morphological stability of the prepared double nanoemulsions and the physicochemical, rheological, and sensory properties of the yogurt enriched with these nanoemulsions. Materials and Methods: Double nanoemulsions containing tryptophan were produced and their characteristics were evaluated using particle size and zeta potential measurements, scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and Fourier-transform infrared spectroscopy (FTIR). The nanoemulsion was then added to stirred set yogurt, and the physicochemical, rheological, and sensory properties of the enriched yogurt were examined. Findings: The produced double nanoemulsion successfully retained tryptophan within its structure and exhibited desirable characteristics, including appropriate physical and morphological stability. The yogurt fortified with this nanoemulsion showed significant improvements in physicochemical and sensory properties, including color, taste, and texture, compared to regular yogurt, although the differences. Conclusion: The results of this study indicate that the dual nanoemulsion containing tryptophan can be an effective method for enriching yogurt with this amino acid. This approach not only enhances the nutritional properties of yogurt but also helps mitigate challenges related to taste and stability of tryptophan, potentially leading to the development of more health-promoting food products. Keywords: Duble nanoemulsion, Tryptophan, Oleogel, Functional yogurt