Magnetic Nanoparticles based on Natural Silica as a Methyl Ester Forming Acid Catalyst

Natural silica has advantages in various fields such as catalysts, because it is easily obtained and applied in the chemical reaction process. The synthesis of natural silica-based magnetic acid catalyst, MSNP/SO42- aims to obtain a large yield from the reaction process between oleic acid and methanol to form methyl ester. Natural silica obtained from geothermal waste was washed with distilled water, then sol gel method was applied at pH of 4-6 to obtain SiO2 nanoparticles. FeCl3 was added to achieve the magnetic properties, and the cetyl trimethyl ammonium bromide (CTAB) is varied in order to attain optimal mesoporous size. Brunauer emmet teller (BET) results showed optimum results from 1: 2 molarity ratio between silica and CTAB with a surface area of 520.94 m2/g. The acidic properties were obtained by immersion using H2SO4 0.5 M. The catalyst were tested for the acidic and magnetic properties using temperature programmed desorption ammonia (TPD-NH3) and vibrating sample magnetometer (VSM) characterization resulting intotal acidity of 0.2488 mmol/g and. softmagnetic type, respectively. The BET surface area of the sulfate modified into MSNP/SO42-, was decreased by 114.44 m2/g. Application of MSNP/SO42- as a catalyst for forming methyl esters obtained a percentage of 85.41% yield based on the gas chromatography mass spectrometry (GC- MS) results.

Bacterial Cellulose Production in The Overripe Guava Juice by Acetobacter xylinum as A Solution to Reduce Organic Waste

The exploration for a new cost-effective carbon source with shorter fermentation process for high yield BC production is still needed. In this study, bacterial cellulose (BC) was synthesized by Acetobacter xylinum using overripe guava juice as a carbon source. The results showed that A. xylinum was able to grow on the overripe guava juice with different concentration and produced BC after two days incubation. In the later on, the BC is called as nata de guava. The overripe guava juice which containing reducing sugar content 23 g /L (substrate 100%) at pH 4 produced the thickest BC (1.267 cm). This study showed due to the high reducing sugar and protein contents in the overripe guava, without the addition of carbon and nitrogen from external sources, BC could be formed. Considering the huge disposal overripe guava fruit waste in Java, the present study provides an alternative methodology to synthesize BC. Besides, most importantly, this study provides a new insight to manage organic waste specifically from overripe guava fruit rather than the waste being thrown away and becoming organic waste generation. Keywords: bacterial cellulose, Acetobacter xylinum, overripe guava, organic waste

Study of Total Phenolic, Total Flavonoid, Scopoletin Contents and Antioxidant Activity of Extract of Ripened Noni Juice

Extraction of ripened noni juice has been carried out using ethanol and water. The purpose of this study was to determine the total phenolic, total flavonoids, scopoletin, content and antioxidant activity of the ripened noni juice extract. The activity test was carried out on the ripened noni juice extract without and with the addition of ethanol and water solvent. The phytochemical assays of ethanol extract of the ripened noni juice showed that thetotal phenolic content was 3,94 mg gallic acid equivalent/g extract, the total flavonoids was 0,59 mg quercetin equivalent /g extract, the IC50 antioxidant activity was 24,92 mg/L, scopoletin content was 2,45 mg/gram.Keywords : Antioxidant, flavonoids, phenolic, ripened noni juice, scopoletin

Comparison of real time PCR and conventional PCR by identifying genomic DNA of bovine and porcine

Bovine and porcine are poultry meat that consumed worldwide particularly in Southeast Asia.Both of them are prone to food counterfeit owing to several factors such as price, appetite and Halal status. Sensitive and selective analytical methods are required to control meat products that distributed to markets. This paper studied the sensitivity between real – time and conventional PCR or known as qPCR and cPCR, respectively. Bovine and porcine were samples used to verify the sensitivity of them. Nevertheless, those instruments did not show a specific difference during DNA analysis of bovine and porcine. In conventional PCR, two pairs of DNA primers targeted cytochrome b (Cyt b) was analyzed, resulting of 120 and 131 amplicons, respectively. While qPCR applied to analyze porcine and bovine DNA. The detection limit of qPCR after porcine and bovine analysis were at 0.004 and 0.007 µg/µL, respectively. Results demonstrated the qPCR was reliable for verifying porcine and bovine DNA compared to conventional PCR. Furthermore, the study concluded that the developed assay can be easily employed for the identification of porcine and bovine tissue in food products in low resource areas.

Synthesis of Nanofiber from Polyvinyl Alcohol (PVA)-Collagen Using Electrospinning Methods

Polyvinil alcohol (PVA) polymer can be used as matrix to be mixed with collagen in the subtance of primary wound dressing material to cover wound that prevents growth of bacteria and enhanced tissue formation. Collagen fiber is fragile, so important to combined with PVA to obtain better mechanical properties. The PVA-collagen fibers are prepared in aqueous solutions with PVA (10%) and collagen concentration (1% and 2%) using electrospinning method and the effect of voltage 15 kV, 19 kV, and 23 kV. Analysis of functional groups show that the presence of identical compounds produced and new functional groups are not formed. SEM data show that the effect of variation of voltage and collagen concentration on the resulting morphology of fiber. PVA-collagen 2% fibers produce continuous fibers, has a diameter 284-426 nm, thickness 0.0324-0.0483 mm and has a high percent of elongation so it can be used as a wound dressing material.

Tapioca Waste-Methyl Methacrylate Irradiation for Biodegradable Plastic Raw Materials

Nuclear technology can be applied not only as an energy (electricity) but also in industry as as an initiator on polymer reaction. Tapioca waste is used due to its biodegradability properties. Tapioca waste gel is formed by adding equal aquades ratio to waste weight. After gel formed, several concentrations of methyl methacrylate (w/w) is added to the gel then packed into 150 mL ampule. Using Co-60 gamma irradiation source, gel is irradiated at 5 kGy absorbed dose. Gel is extracted using acetone to get rid of sample from impurities. Glycerol as a plasticizer is added to the gel to increase polymer flexibility. Gel-Glycerol mixing is done at 60ºC, 250 rpm for one hour by adding aquadest. To analyze mechanical properties, firstly, we need to mold samples using pressurized-hot press machine. Film is formed to type 5 specimen (dog bone, astm d638-14). Specimen is tested by analyzing tensile strength characteristics. Fabrication of biodegradable plastic based packaging by using starch has an increasement of mechanical and thermal properties at 5 kGy absorbed dose. Methyl methacrylate 25, 50, 75, 100, 125 and 150% addition to the solution has 10-24 MPa tensile strength. Gel fraction has range between 88-100%. Even the lowest ratio of monomer addition can provide highest gel fraction to improve mechanical properties of tapioca waste.

Effect of Liquid Media Composition on Alpha-Glucosidase Inhibitory Activity from Aspergillus elegans SweF9

This study aims to determine the effect of liquid media composition on the inhibitory activity of α-glucosidase from endophytic fungus Aspergillus elegans SweF9 isolated from seaweed (Macroalgae Euchema sp). Fermentation was carried out in three types of liquid media, namely: potato dextrose broth (PDB), potato malt peptone (PMP), and Czapek-dox broth (CDB), which was incubated for 10 days at room temperature, with static conditions. Ethyl acetate solvents were used to extract active metabolites from fungal biomass and filtrate from each media. Antidiabetic activity was measured based on inhibition of enzyme α-glucosidase. The results showed that filtrate extract of A. elegans SweF9 which was cultured on the media PDB showed highest inhibitor activity to the α-glucosidase enzyme with an IC50 value of 1.74 µg / mL compared to other extracts. Based on these results, the PDB media is an appropriate medium for culturing A. elegans SweF9 to produces secondary metabolites that can be used as a new source of antidiabetic agents.

Enrichment of Omega-3 from Anchovy (Stolephorus sp.) Fish Oil by Enzymatic Hydrolysis

Anchovy (Stolephorus sp.) is an economically important fish in Indonesia. Anchovy contains Omega-3 that important to maintain the health of the heart and brain. This study aimed to enrich the Omega 3 content of anchovy oil from the North Sea of West Java. The extraction of anchovy oil was carried out by the soxhlet method. Enrichment of omega 3 from anchovy fish oil is carried out by hydrolysis with a commercial lipase enzyme at concentration 500, 1000, 1500 and 2000 unit/600g fish oil, for 5, 10, 15 and 20 hour. Before hydrolysis, fish oil was added with solvent water, ethanol, toluene, and n-hexane. Omega 3 content of fish oil products were analyzed by using Gas Chromatography (GC) with FID detector with retention time 14.068 min and 15.506 min for α-Linolenat (ALA) and eicosapentaenoic (EPA), respectively. The results showed the highest omega 3 content (ALA 0.54% and EPA 1.103% ) was produced by addition n-hexane with a ratio 1:6 with the concentration of lipase was 1000 units for 20 hours.