2.2. Dried Red Seaweed Preparation

Traditionally, the red seaweed is washed and dried under sun light, then collected in the evening. The next day, the process is repeated for 7 cycles over 7 days. In the current study, the traditional sun light drying method was simulated. Five hundred grams frozen seaweed for each batch was placed under running tap water until completely thawed to tap water temperature (25 °C). Then, the seaweed was evenly placed on a stainless mesh (18 × 10 cm, L × W) to a thickness of about 1 cm. The red seaweed was dried under sun for 2 h (the luminance was around 35,000 to 50,000 lux) or dried under a 300 W LED halogen lamp (18 × 16 × 11.5 cm, L × W × H) (Anjia Light Store, Kaohsiung) for 2 h (the average luminance was 15,000 to 20,000 lux) at a temperature of around 60 °C, placed at the center of the algae during the drying process. After the drying process, the red seaweed was stored at night. The next day, the red seaweed was washed and dried under the sun for 3 and 7 cycles (sun drying), dried by halogen lamp for 7, 9, and 12 cycles (halogen lamp drying), respectively. The additional drying cycles under halogen lamp drying (up to 12 cycles) made the gel harder. An oven-dried red seaweed (50 °C for 4 days) reaching a moisture content of 10–13% was used as a control sample. Another red seaweed sample was dried in an oven with exposure to a UV-C light at a distance of 30 cm from the sample surface (Model A-01, 253.7 nm; 30 W, PJLink, Taipei, Taiwan) to simulate sun light for the oven drying process.