Due to wonderful taste, rich nutrition and biological functions, many marine green algae in the genus Caulerpa have been recently developed as candidates for green caviar. A novel water-soluble sulfated xylogalactomannan CO-0-1 was obtained from the green algae Caulerpa okamurae . CO-0-1 was mainly composed of mannose (Man), galactose (Gal), and xylose (Xyl) at the ratio of 4.4:4.0:1.4 with the molecular weight at 470 kDa and the sulfate content at 12.78 %. The sulfated xylogalactomannan had Man at the backbone with →4)-β-D-Man p -(1→ and →2)-β-D-Man p -(1→ as the main chain and branches at O -3 position. The side chains contained →3)-β-D-Gal p -(1→ and minor →2)-β-D-Xyl p (1→. The sulfate groups only distributed at the side chains and at O -6 position of →3)-β-D-Gal p -(1→ and O -4 position of (1→2)-β-D-Xyl p . The anticoagulant activity indicated that CO-0-1 displayed intrinsic anticoagulant and specific anti-thrombin activities. The investigation expanded the utilization and development scene and scope of the green algae Caulerpa okamurae .
Summary The effects of Caulerpa lentillifera (CL) extract incorporation on antioxidant activity, antibacterial activity, water stability, and physical properties of the chitosan/gelatin (CS/GEL) films were studied. The CL extract containing CS/GEL composite film was prepared by the casting method. The effect of CL content (1%, 3%, 5%) on the antioxidant properties, thermal property, mechanical properties, barrier properties, water stability and water contact angle of CS/GEL films was evaluated. With the increase of CL extract content, bumps and micro-pores appeared on the surface and cross-section of the composite films. The water contact angle, water solubility, and water absorption swelling rate of the composite films were improved with the addition of CL; therefore, the composite films exhibited better water stability. The TS of films were enhanced (from 12.57 to 23.66 MPa). Compared with the normal CS/GEL films, the CS/GEL-CL films exhibited better antioxidant with DPPH scavenging capacity values of 72.6% and could effectively slow down the lipid oxidation of refrigerated pork samples during storage, such as lower accumulation of free fatty acid content and fluorescence compound formation. This suggested that CS/GEL-CL film might be suitable as active films for food packaging.
The effect of weakly charged insoluble karaya gum (KG) on zein colloidal nanoparticles (ZKGPs) for stabilizing Pickering emulsions was investigated. Due to weak surface charge, KG could cover the surface of zein particles by hydrogen bonds and weak electrostatic interactions. With the increase in coverage, the zeta potential of ZKGPs changed from positive to negative values close to zero and the average particle size tended to become larger. The closest neutral wettability (89.85°) was achieved when the zein/KG mass ratio was 1:1. The samples prepared with high oil volume fraction (φ = 0.5–0.75) and high particle concentration (1.0–1.3 %, w / v ) formed emulsion gels easily and showed higher storage stability. CLSM images also confirmed that ZKGPs could be distributed in the continuous phase to enhance the emulsion network structure. Consequently, weakly charged ZKGPs reduced the emulsification energy barrier and increased the coverage and steric hindrance of particles at the oil/water interface. These findings provide new ideas for the development of stable Pickering emulsions for application in food textural modification as well as encapsulation and delivery of bioactive substances.