Encapsulated fucoxanthin improves the functional properties and storage stability of Undaria Pinnatifida and apple freeze-dried snack food during accelerated storage

Carotenoids, recognized for their antioxidant and anti-aging properties, are commonly used in functional foods. To enhance the application of fucoxanthin (FX) in the food industry, this study employed the ion gel method for encapsulating FX and combined it with raw materials such as Undaria pinnatifida homogenate and apple pieces to create freeze-dried crunchy chunks. The study evaluated the effects of encapsulated-FX on the functional and structural characteristics of the Undaria pinnatifida and apple freeze-dried chunks over accelerated storage period under high temperature and humidity. Various analyses were conducted, including physicochemical properties, texture analysis, color evaluation, sensory assessment, and simulated digestion analysis. The results demonstrated that the FX-rich freeze-dried crunchy chunks exhibited favorable structural properties and appealing flavor. Notably, after the accelerated storage period, the encapsulated-FX maintained significant antioxidant activity, along with excellent thermal and light stability, indicating high storage stability. Additionally, the main ingredients, sodium alginate (SAA) and pectin (PE), significantly enhanced the stability of FX during in vitro digestion. This study provided a straightforward approach for producing freeze-dried snack foods rich in stabled-FX, contributing to the diversity of value-added algae products. Furthermore, it laid a theoretical foundation and reference for the future development of nutritional products.