Analysis of Bioactive Peptides of Proteins Isolated from Polysaccharide Extract of Caulerpa lentillifera

Sea grapes (Caulerpa lentillifera) are commonly popular for fresh consumption. They are food grade selected from size, cluster length, and green color characteristics. However, the portions that do not meet the specification are discarded, accounting for 60-70% of the total harvest. Previously, there has been an increase in the value of Caulerpa waste by polysaccharide extraction to obtain a partially purified polysaccharide and analysis of essential compounds in the extract. Studies have revealed that polysaccharide extract contains approximately 13% protein by weight. Therefore, there is an interest in studying the proteins found in the extract. To enhance the value, knowledge, and utilization of the extract for application in functional ingredient industry, food supplements, and pharmaceutical industries, and to reduce waste from Caulerpa waste, this research aims to identify bioactive peptides from the partially purified polysaccharide extract of Caulerpa waste. Water and/or different buffers are used as solvents to extract proteins through sonication, followed by enzyme digestion. Peptide samples are analyzed using LC/MS-MS with Agilent MassHunter software. Peptide types are identified using Spectrum Mill by comparing with C. lentillifera genome database and a bioactive peptide database using SmartBioPep, an AI-based bioactive peptide analytical platform, to identify peptide sequences that are bioactive peptides from the partial purified polysaccharide extract, particularly antimicrobial peptide.