Fabrication of emulsion gels based on sonicated grass pea (Lathyrus sativus L.) protein as a delivery system for β-carotene: Kinetic modeling and release behavior

Abstract

In this study, the release behavior and encapsulation efficiency of β-carotene in emulsion gels fabricated by sonicated grass pea protein isolate (GPPI) under simulated gastrointestinal conditions were investigated. Therefore, the emulsion gels stabilized by sonicated GPPIs (8% w/v) and corn oil (20% volume fraction and containing 0.5% w/w of β-Carotene) were induced by transglutaminase. The emulsion gels prepared by sonicated GPPIs exhibited sustained release of β-carotene. The Ritger-Peppas model best described the release behavior of β-carotene from the emulsion gels, indicating that the predominant release mechanism was non-Fickian diffusion. Sonicated GPPI-based emulsion gels exhibited higher β-carotene encapsulation efficiency (97.75%) and loading capacity, attributed to increased protein surface hydrophobicity, TGase cross-linking between ϵ-(γ-glutamyl) lysine residues, and the formation of smaller protein particles through ultrasonic treatment. Incorporation of β-carotene within emulsion gels was confirmed by FTIR analysis. Emulsion gels prepared using sonicated GPPIs at 75% amplitude demonstrated approximately fivefold improved bioaccessibility and enhanced retention of β-carotene during storage (20 days) compared to emulsion gels prepared using native GPPI. These findings suggest that structural modification of protein and gel structure can significantly affect the bioaccessibility and stability of β-carotene in the product.