In this study the possibility of replacing current surfactants in chocolate formulations with natural lipids extracted from spinach leaf (SPLIP) or spinach chloroplast (CH.SPLIP) was evaluated. SPLIP and CH.SPLIP were extracted with chloroform/methanol following enzyme deactivation with hot isopropanol. Results showed a higher extraction yield for SPLIP while glycolipids were more concentrated in CH.SPLIP. Sugar/oil suspensions with dispersed volume fractions of 0.28, 0.33 and 0.37 containing 0.1% to 0.7% (w/w) surfactant (SPLIP, CH.SPLIP, lecithin and PGPR as commercial references) based on oil phase were prepared and analyzed in shear rheology. Apparent viscosity at 40 s-1 was significantly lower for the natural surfactants compared to lecithin at 0.5-0.7% (w/w) addition. With regard to yield stress, taken as the shear stress at 5 s-1, both natural surfactants showed comparable performance to PGPR at 0.3% to 0.7% addition. As SPLIP and CH.SPLIP behaved similar (p > 0.05), SPLIP, due to higher extraction yield, would be the preferred choice for application in chocolate matrices.
This study developed and characterized a pH-sensitive gelatin-based film incorporated with anthocyanin from roselle extracts (Hibiscus sabdariffa) at varying concentrations (0%-15%). The addition of anthocyanins significantly influenced the film's properties, reducing tensile strength from 1.5 to 1.1 MPa while increasing elongation at break from 312% to 416%. Water vapor permeability also increased with anthocyanin concentration, ranging from 1.02 to 1.47 × 10-⁸ g·m-¹·s-¹·Pa-¹. The film displayed a distinct color change from red to yellow-green across pH 3-10 and when exposed to ammonia gas, highlighting its potential for real-time detection of volatile basic compounds. Fourier transform infrared analysis revealed molecular interactions between gelatin and anthocyanins, with increasing roselle extract concentrations as it showed enhanced amide A, I, II, and III functional groups. Scanning electron micrographs revealed increased surface roughness and microstructural changes with anthocyanin addition. These findings demonstrate the potential of 15% roselle anthocyanin-gelatin films as eco-friendly, pH-sensitive smart packaging materials for food applications.