High temperature short time blanching enhances the antioxidative properties of sea grapes ( Caulerpa racemosa) powder

Green alga sea grapes (Caulerpa racemosa) were consumed by Asian and Pacific Island people. It contains antioxidant compounds, such as phenols and caulerpin (CAU) that can potentially prevent disease. These sea grapes need to be blanched before drying to minimize oxidation damage. This research aims to understand the effect of temperature during hot water blanching (HWB) on the antioxidant activities, TPC, CAU, color, and moisture content of sea grapes powder. HWB temperatures used 70, 80, 90, and 100 °C at 20 seconds. The HWB had a more significant increase in antioxidant activity than control of sea grapes powder. The 100 °C had the highest value on ABTS, FRAP, and TPC, respectively 13.18 ± 0.13 (μg TE/g), 1.52 ± 0.03 (mg Ferro E/g), 0.96 ± 0,01(mg GAE/100 g). It is increasing its value because enzyme deactivation is better in high temperatures. Short time with high-temperature blanching can prevent the loss of bioactive compounds. CAU has specific aromatic rings, -NH, C=O, and -O-; all samples have peaks at these frequencies. Blanching has an intense green color (-a∗) because it can increase color quality but has no significant result in moisture content. This study suggested blanching sea grapes can be done at 100°C for 20 seconds.