Development of polysaccharide production form Caulerpa waste

Caulerpa lentillifera has become a famous ingredient for food during the last five years in Thailand. The production capacity of fresh C. lentillifera biomass was around 25 ton/month. Many farms in the southern region along the coastlines of the Gulf of Thailand. The selling price of C. lentillifera biomass for food grade is approximately 500-800 baht per kilogram. However, a limitation of C. lentillifera is its short shelf life (only 5–6 days), after which it is discarded. Moreover, around 60%–70% C. lentillifera of biomass after harvesting and grading is discarded as waste. Therefore, we would like to increase the value of C. lentillifera waste and transform poor quality material to new products with high value-added. Our previous study found that a polysaccharide yield of around 25% of dry weight was obtained under the following optimized conditions: two-stage extraction (60 min/stage) using a ratio of 1:15 (w/v) at 90°C, and two times precipitation by the final concentration of 75% ethanol. This polysaccharide extract demonstrated a-glucosidase inhibitory activity with an IC₅₀ value of 13.59 mg/ml. This result suggests that the polysaccharide extracts could potentially be used as a food supplement for preventing diabetes disease. In addition, the economic analysis also showed an economic feasibility for producing polysaccharide extracts from C. lentillifera waste (Chaiklahan et al. 2020). This is an alternative for farmers in order to increase the value of C. lentillifera waste.

Although, we have a knowledge of the optimum conditions for polysaccharide extraction from C. lentillifera, the process scale-up needs to study and develop for providing a suitable equipment/tools and optimization operating conditions in each step. This project aims to develop a polysaccharide production process from C. lentillifera waste in the step of preparation of algae raw materials, separation, polysaccharide precipitation and drying.