Effects of solid-state fermentation of seaweed (Caulerpa racemosa) on antioxidant assay and flavour profile

The effects of solid-state fermentation (SSF) of Caulerpa racemosa on antioxidant properties (total phenolic content (TPC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, Ferric-reducing antioxidant power (FRAP)) and flavour profile were investigated. Additionally, sensory acceptability (9-Point Hedonic Test) and satiety analysis (10-Scale Intention) of oat drinks incorporated with SSF of C. racemosa were also studied. Results of SSF C. racemosa demonstrated that significantly (p<0.05) higher content in TPC, DPPH, IC50 and FRAP (312.30±5.76 mg GAE/100 g, 25.96±0.17 mg AA/100 g, 46.22±0.31 mg/mL, 1106.72±21.82 mg TE/100 g and 206.80±4.76 mg GAE/100 g, respectively). Flavour profile analysis indicated the presence of antimicrobial volatile siloxane compounds; hexamethylcyclotrisiloxane and octamethylcyclotetrasiloxane. These -siloxane group compounds are known to have antioxidant, defoaming, and release coating properties. In addition, results obtained from the sensory evaluation showed that the addition of a different amount of SSF C. racemosa did not significantly (p>0.05) affect the acceptability of instant oat drinks. However, oat drinks incorporated with SSF C. racemosa significantly (p<0.05) increased in fullness from the satiety study. Therefore, value-added SSF C. racemosa can be incorporated into food products to increase its nutritional properties and fullness without affecting the taste.