Integral Mastocarpus stellatus use for antioxidant edible film development

Four sequential aqueous extracts (M1 to M4) were obtained from Mastocarpus stellatus at different temperatures. M1 (extracted at 3 °C overnight) showed higher extraction yield and antioxidant activity than M2 (extracted at 45 °C for 45 min). Extracts M3 and M4, obtained both at 91 °C, were composed predominantly of a κ/ι-hybrid carrageenan. M4 contained higher protein proportion. Based on compositional and structural properties, four films were developed: FM3, FM4, FM3 + M4 and FM3 + M4 + M1. FM4 was green colored, more opaque, and water resistant, stronger and slightly less stretchable than FM3. The mixture of M3 and M4 for film development resulted in a film with intermediate characteristics. The addition of M1 to FM3 + M4 provided mainly proteins and sulfated compounds, resulting in a more water resistant film, with suitable mechanical properties in both tensile and puncture test, and much higher antioxidant activity.