Green seaweed is currently underused compared with other major seaweed types. Many scientists have reported applications of the green seaweed Ulva in various fields in recent years, which makes it a candidate for biomass production in industrial biorefineries. Ulva contains a unique polysaccharide called ulvan, which is being considered for medicinal and pharmacological applications. Ulvan is a sulfated polysaccharide including rhamnose and glucuronic acid residues, which has a range of bioactivities, including immunomodulatory, antimicrobial, and anticoagulant properties. The biocompatibility of ulvan makes it a versatile candidate for biomaterial design. This review presents an in-depth analysis of the potential applications of ulvan, starting with extraction methods and structural/biological characterization and moving on to biomaterial design. We also highlight the advantages of ulvan over traditional seaweed polysaccharides such as agar, carrageenan, and alginate.

Spirulina platensis is a microalga containing protein and other nutrients, also pigments which has several advantages in food and pharmaceuticals. Phycocyanin is a blue pigment from Spirulina sp. composed by α and β polypeptide with phycocyanobilin. Phycocyanin can be extracted by ultra-sonication method. However, this pigment can be easily degraded because of its instability caused by pH, temperature, and light. One of methods for maintaining the stability is encapsulation by coating material. Water soluble chitosan (WSC) is known as a low-molecular weight and low toxic coating material dissolve in water. The purposes of this study were to determine phycocyanin extraction with different time and evaluate the stability of phycocyanin in WSC nanoparticles. Phycocyanin-WSC nanoparticles were prepared with three different ratio of WSC to phycocyanin i.e 1:1, 1:0.75, 1:0.5 (w/w). Extraction phycocyanin using ultrasonicator for 15 min showed the highest concentration (1.28 mg/mL) and yield (2.56%). The smallest size and narrow polydispersities of phycocyanin-WSC nanoparticles was achieved with ratio of WSC to phycocyanin of 1:0.75 (w/w). Encapsulation of phycocyanin in WSC nanoparticle enhanced the stability at 50°C for 90 min. Encapsulation can be used for any supplement application.

Kitosan merupakan polimer alami bermuatan positif yang dapat diaplikasikan bidang farmasi sebagai penghantar obat. Akan tetapi, kitosan komersil memiliki berat molekul besar dan derajat deasetilasi yang rendah, sehingga aplikasinya terbatas akibat kelarutannya yang rendah pada air. Penelitian ini bertujuan untuk menentukan pengaruh metode depolimerisasi dua kelas kitosan yang beredar dipasaran terhadap karakteristiknya. Jenis kitosan yang digunakan yaitu pharmaceutical grade dan food grade untuk menghasilkan oligokitosan. Metode depolimerisasi kitosan yang digunakan adalah iradiasi sinar UV-C (75 menit), hidrolisis enzim papain (15 g/L selama 16 jam, 40oC dan pH 5) serta kombinasi UV dan enzim. Hasil penelitian menunjukkan bahwa grade kitosan dan metode depolimerisasi mempengaruhi karakteristik kitosan depolimerisasi yang dihasilkan. Ketiga metode yang digunakan pada kitosan pharmaceutical grade menghasilkan oligokitosan yang dapat larut langsung pada air dengan pH netral dengan rendemen >62%, derajat putih 99,33%, berat molekul 85%. Kitosan food grade yang melalui depolimerisasi dengan metode berbeda belum dapat larut dalam air dengan pH netral. Kitosan food grade yang melalui depolimerisasi kombinasi UV+enzim memiliki kualitas derajat deasetilasi yang identik dengan kitosan pharmaceutical grade.