The aim of this study was to determine the best concentration of E. cottonii seaweed porridge in the formulation of peel off gel masks. The main materials used in this study were <em>E. cottonii</em> and other basic substances of peel off gel mask. The analytical methods used were the total microbial and antioxidant test on the E. cottonii slurry preparation. Mask preparations were analyzed for physical stability, pH, duration of preparation, drying, viscosity and homogeneity. The experimental design used was a Completely Randomized with four treatments by adding <em>E.cottonii</em> porridge 0%, 10%, 15% and 20% respectively  with two replications.The results showed that the best peel off gel mask was formulation with the addition 20% of E.cottonii. Microbes were not found in <em>E. cottonii</em> porridge. The antioxidant activity of <em>E. cottonii</em> porridge had IC50 value of 137.35±0.35 μg / mL. Consumer acceptance of products through sensory testing in the category of likes. The peel off gel mask has good physical stability, proven by no changes in color, odor as well as  gel texture. The pH value of the preparation of peel off gel mask is  in line with  SNI and pH balance of normal human skin. The best viscosity value of peel off gel mask is 14,003 cps. The time needed for the mask to dry for an average of 25 minutes and homogeneity is characterized by the absence of secondary particle aggregation.

UV radiation has negative effects on the health of the skin. The use of sunscreen everyday can absorb at least 85% sunlight at a wavelength of 290-320 nm. The purpose of this research was to find the best formulation of seaweed porridge Sargassum sp. and Eucheuma cottonii as a sunscreen cream qualified by antioxidant activity, SPF, physical evaluation of cream analysis and stability analysis. Cream formulation comprised of 5%, 6%, 7% and control. The best percentage of stocks from cream E. cottonii and Sargassum sp. were the cream preparation C. The value of antioxidant activity and SPF were 185±0.02 mg/mL and 2.1988, respectively. The pH value belongs to alkaline. Cycling test showed the cream preparation of the slurry E. cottonii and Sargassum sp. remained stable, there was no phase separation and discoloration. Centrifugal test results indicate that the cream has a shelf life for 1 year due to the absence of phase separation after given effect centrifugal force with a speed of 3,800 rpm for 5 hours.

Abstract. Luthfiyana N, Bija S, Nugraeni CD, Lembang MS, Anwar E, Laksmitawati DR, Nusaibah, Ratrinia PW, Mukmainna. 2022. Characteristics and antibacterial activity of chitosan nanoparticles from mangrove crab shell (Scylla sp.) in Tarakan Waters, North Kalimantan, Indonesia. Biodiversitas 23: 4018-4025. The aim of this study was to determine the characteristics and antibacterial activity of chitosan nanoparticles from mangrove crab shells (Scylla sp.) in Tarakan Waters, North Kalimantan, Indonesia. Chitosan was produced from deproteination, demineralization, and deacetylation processes. Nanoparticles of chitosan were produced by the ionic gelation method. The quality of produced chitosan was tested, and characterized the obtained nanoparticles of chitosan. The results showed that the yield of chitosan was 5.82 ± 0.02%, moisture 1.66 ± 0.05%, ash 1.59 ± 0.21%, nitrogen 1.32 ± 0.06%, and degree of deacetylation (DD) 76 ± 0.00%. All results were in accordance with the Protan Laboratory and Food Safety Authority (EFSA) 2010 standard. Next, the characteristics of chitosan nanoparticles showed that the highest intensity was 15.69 nm, with a polydispersity index of 0.346 and a zeta potential of -26.1 mV. The morphology of chitosan nanoparticles was observed by scanning electron microscopy, energy-dispersive x-ray spectroscopy (SEM-EDX) at 7,500 times magnification. Several elements, such as C and O, were found as constituent elements of chitosan, whereas Mg, Al, P, and Ca, were metal impurities of the shell. Na was derivate from NaTTP, a reactant from mangrove crab nano chitosan. The results of antimicrobial activity revealed that 1% (P4) chitosan extract showed highest zone of inhibition i.e. 13.55 mm and 13.43 mm against Staphylococcus aureus and Staphylococcus epidermidis, respectively.

Abstract<br />The use of sunscreen is highly recommended to protect the health of the skin from ultraviolet radiation.<br />The aim of this study were to get the best ratio sunscreen preparation of porridge E. cottonii and Sargassum<br />sp. through the total test microbes, antioxidants and SPF value, get a stable cream preparations physically<br />through sensory test, pH, consistency, Cycling test and centrifugal test. The main materials used were E.<br />cottonii, Sargassum sp. and raw materials stocks cream. This study used a completely randomized design<br />(CRD), which consisted of four treatments with two replications.The results showed that the best ratio of<br />sunscreen cream was cream with the addition of E. cottonii and Sargassum (1:1). The result obtained was<br />the absence of microbs at creams and porridge E. cottonii and Sargassum sp. The antioxidant activity of E.<br />cottonii porridge 127.23 ± 2.77μg/mL, Sargassum sp. 119.66 ± 0.25 μg/mL, and cream 83.4 ± 0.03 μg/mL.<br />Cream SPF value was 7.03 ± 0.01. Consumer acceptance of the products through sensory test ranged from<br />normal to like. Sunscreen creams had good physical stability and the cream has a shelf life preparation one<br />year.<br /><br />

The use of sunscreen is highly recommended to protect the health of the skin from ultraviolet radiation.<br />The aim of this study was to get the best ratio sunscreen preparation of porridge E. cottonii and Sargassum<br />sp. through the total test microbes, antioxidants and SPF value, get a stable cream preparations physically<br />through sensory test, pH, consistency, Cycling test and centrifugal test. The main materials used were E.<br />cottonii, Sargassum sp. and raw materials stocks cream. This study used a completely randomized design<br />(CRD), which consisted of four treatments with two replications.The results showed that the best ratio of<br />sunscreen cream was cream with the addition of E. cottonii and Sargassum (1:1). The result obtained was<br />the absence of microbs at creams and porridge E. cottonii and Sargassum sp. The antioxidant activity of E.<br />cottonii porridge 127.23 ± 2.77μg/mL, Sargassum sp. 119.66 ± 0.25 μg/mL, and cream 83.4 ± 0.03 μg/mL.<br />Cream SPF value was 7.03 ± 0.01. Consumer acceptance of the products through sensory test ranged from<br />normal to like. Sunscreen creams had good physical stability and the cream has a shelf life preparation one<br />year.<br /><br />