Physicochemical Characterization, Sensory Evaluation, and In Vitro Digestion of Passion Fruit Frozen Desserts Incorporating Lutein-Loaded Nanoemulsions

Abstract

Lutein, a carotenoid with antioxidant activity and a natural yellow colorant, is notable for its protective role in the ocular macula, reducing the risk of age-related eye diseases such as age-related macular degeneration (AMD). Its application in foods is limited by its sensitivity to heat, light, and low pH. This study proposes microencapsulation via nanoemulsions (formulated with medium-chain triglycerides and phospholipids through high-pressure homogenization) to stabilize lutein in frozen desserts, including reduced sugar versions. The formulations were evaluated for their physicochemical properties, in vitro bioaccessibility (simulating conditions for both adults and the elderly), and sensory acceptance. Over 180 days of storage, carotenoid stability was maintained, while the microstructure of the frozen system influenced parameters such as hardness and melting kinetics. In vitro digestion revealed that approximately one-third of the lutein was released during the intestinal phase, with similar release profiles for both adults and elderly individuals. Sensory analyses (affective tests and check-all-that-apply [CATA]) indicated good acceptance, especially for the formulations containing nanoemulsions. These results demonstrate that nanoemulsions protect lutein without compromising its technological or sensory properties, thereby enabling the development of functional frozen desserts with natural colorants and a significant amount of bioaccessible lutein after in vitro digestion, contributing to the advancement of innovative functional food products.