## 1 Introduction
The choice of the lipid phase in nanoemulsions, typically composed of edible oils classified as GRAS (generally recognized as safe), is crucial for enhancing the solubility, stability, and bioaccessibility of hydrophobic bioactive compounds like lycopene. Different vegetable oils with varying fatty acid compositions can significantly affect the physico-chemical properties, release profiles, and bioaccessibility of the encapsulated compounds. Selecting an appropriate oil is therefore key to optimizing the delivery and effectiveness of bioactives in functional beverages [23; 24; 25; 26]. Nanoemulsions, due to their small droplet size, provide a larger surface area for digestive enzymes, which improves the solubilization and incorporation of hydrophobic compounds into mixed micelles formed in the small intestine. Mixed micelles, formed by the action of bile salts in the small intestine, are crucial for the solubilization of hydrophobic compounds, aiding their absorption in the digestive track. Nanoemulsions rapidly form mixed micelles, thus promoting the solubilization of lipophilic compounds [27]. Investigating these factors can shed light on the effectiveness of nanoemulsion-based delivery systems in overcoming bioavailability barriers, potentially leading to better nutritional results [28; 29; 26]. Recent studies have demonstrated the successful incorporation of polyphenols and lycopene into nanoemulsions, highlighting their potential in creating novel functional food products [7; 19; 25; 28; 30]. Recent advancements in nanoemulsion technology have demonstrated significant improvements in the bioavailability, stability, and bioaccessibility of hydrophobic bioactive compounds like polyphenols and lycopene. Breakthroughs in the use of natural emulsifiers and innovative co-encapsulation techniques have further enhanced the release and absorption of these bioactives in the digestive system. Additionally, studies have shown that modifying the lipid phase and adjusting particle size distribution can significantly increase the bioavailability of these compounds, making nanoemulsion-based functional foods more effective in delivering health benefits. Looking ahead, advancements in nanoemulsion technology signify promising future trends in enhancing the bioavailability, stability, and bioaccessibility of hydrophobic and hydrophilic bioactive compounds from food by-products such as olive and tomato pomace into functional foods and beverages. Breakthroughs in the use of natural emulsifiers and innovative co-encapsulation techniques are set to improve the release and absorption of these bioactives in the digestive system. Innovations such as tailored lipid phases and precise control of particle size distribution are emerging as key strategies to maximize the release and absorption of bioactives in the digestive system. These advancements signal a transformative future for nanoemulsion-based applications, catering to the growing consumer interest in nutrient-rich, health-promoting products [27; 31; 32]. In this context, the present study explored the use of oil-in-water nanomemulsions enriched with polyphenols and lycopene as ingredients in a beverage model based on apple juice. The main focus was to explore the effect of lipid phase and storage conditions on the physicochemical properties and stability of the functional beverage, as well as on the bioaccessibility of encapsulated lycopene and polyphenols. The findings of this study aim at providing insights into the development of functional beverages that leverage the benefits of nanoemulsion technology to deliver health-promoting bioactive compounds effectively. A significant emphasis was placed on the stability of the o/w nanoemulsions and functional beverage at different storage conditions (4, 10, 25, and 40 \({}^{\circ}\)C), aiming at achieving the long-term durability required for beverage applications.