This research offers a novel approach of free chemical preparation to obtain algae-based biopolyol through a ball milling method. The algae-based polyurethane (AlgPU) film was obtained from a casting solution made of ball-milled algal polyol particle and methylene diphenyl diisocyanate (MDI). The characteristics of the material had been investigated using Fourier Transform Infrared, Scanning Electron Microscopy – Electron Dispersive Spectroscopy, Differential Scanning Calorimetry, and Tensile Strength Analysis. The surface area was determined by Brunauer–Emmett–Teller (BET) isotherm, meanwhile the total pore volume was by Barrett-Joyner-Halenda (BJH) isotherm, based on the adsorption-desorption of N 2 . The addition of activated carbon contributed in the increase of functional group and surface area, which were important for the NH 3 –N removal. As a result, the adsorption capacity increased greatly after the addition of activated carbon (from 187.84 to 393.43 μg/g). The results also suggested AlgPU as a good matrix for immobilizing activated carbon filler. The adsorption shows a better fit with Langmuir isotherm model, with R 2 = 0.97487 and root-mean-square error (RMSE) = 33.91952, compared to Freundlich isotherm model (R 2 = 0.96477 and RMSE = 44.05388). This means the NH 3 –N adsorption followed the assumption of homogenous and monolayer adsorption, in which the maximum adsorption was found to be 797.95 μg/g. This research suggests the potential of newly developed material for NH 3 –N removal.

Abstract. Proximate analysis of Dioscorea hispida tubers, collected from five locations around

Agricultural and industrial products need a high performance of packaging that can preserve its properties in a long period. A high-performance bioplastic was developed in this study from wheat Janeng starch. The bioplastics were prepared by casting on the glass plate and formed by phase inversion method. Bioplastics are made from a mixture of starch and glycerol provides transparent films with high tensile strength and elongation value. The optimum bioplastics compositions were 12 % (w/w) of starch and 5 % (w/w) of glycerol as plasticizer. Glycerol was used as a plasticizer to modify its mechanical properties. The addition of glycerol with the concentration of 5 % (w/w) produced a bioplastic with a high tensile strength of 20.95 kgf/mm2 and 42.69 % of elongation. The bioplastics are made from janeng starch can be used for packaging apples and tomatoes slice with a high protective barrier.

New polyurethane membrane from hydroxylated rubber seed oil has been prepared in this study. Hydroxylated process of rubber seed oil improved 135.30% of hydroxyl number and decreased 73.91% of iodine number of rubber seed oil. Optimum polyurethane membrane was obtained at the composition of hydroxylated rubber seed oil:hexamethylene-1,6-diisocyanate was 5:7 v/w. The membrane was homogeneous, dry, smooth, slightly stiff and brownish yellow. The clean water flux and rejection factor of the membrane were 0,544L / m 2 .h.bar and 98.86%, respectively. FTIR spectra indicated the formation of urethane bond (N-H at 3308 cm -1 ). Thermal analysis showed two stages of decomposition at 223 o C and 386°C. The membrane exhibited a strong and elastic properties with a tensile strength of 1.13 kgf/mm 2 and elongation 215.36%.

Minyak biji karet dapat dimanfaatkan untuk pembuatan membran poliuretan. Minyak biji karet memiliki bilangan hidroksi 40,33 mgKOH/g dan bilangan iod 154,05 gI2/g. Sintesis membran poliuretan menggunakan metode ikatan silang. Ikatan silang terbentuk dengan mereaksikan minyak biji karet sebagai sumber gugus -OH dengan heksametilen-1,6-diisosianat sebagai sumber gugus -NCO.  Membran poliuretan yang optimum dihasilkan pada komposisi 4,55:5 (g/g) memiliki sifat homogen, kering, elastis, berwarna kuning kecoklatan, bergelombang, fluks 0,544 L/m2.h.bar dan faktor rejeksi 100%. Hasil karakterisasi membran menunjukkan terbentuknya ikatan uretan pada bilangan gelombang 3480 cm-1, struktur morfologi membran padat, memiliki dua tahap dekomposisi pada 210 oC dan 392 oC, titik transisi gelas 65 oC, kekuatan tarik 1,03 kgf/mm2 dan elongasi 497,14%. Dari hasil karakterisasi membran poliuretan, membran tersebut dapat digolongkan pada tipe membran reverse osmosis.

Considering the significance of its demand around the world, the accurate determination of fish freshness with a simple and rapid procedure has become an interesting issue for the fishing industry. Hence, we aimed to fabricate a new optical pH sensor based on a polyelectrolyte (PEC) membrane of pectin–chitosan and the active material chromoionophore ETH 5294. A trial-and-error investigation of the polymer compositions revealed that the optimum ratio of pectin to chitosan was 3:7. With an optimum wavelength region (λ) at 610 nm, the constructed sensor was capable of stable responses after 5 min exposure to phosphate-buffered solution. Furthermore, the obtained sensor achieved optimum sensitivity when the PBS concentration was 0.1 M, while the relative standard deviation values ranged from 2.07 to 2.34%, suggesting good reproducibility. Further investigation revealed that the sensor experienced decreased absorbance of 16.67–18.68% after 25 days of storage. Employing the optimum conditions stated previously, the sensor was tested to monitor fish freshness in samples that were stored at 4 °C and ambient temperature. The results suggested that the newly fabricated optical sensor could measure pH changes on fish skin after 25 h storage at room temperature (pH 6.37, 8.91 and 11.02, respectively) and 4 °C (pH 6.8, 7.31 and 7.92, respectively).

Mushrooms contain a substance known as glutamic acid, that produce a savory taste which has the potential to be developed into a natural flavoring. The research began with the determination of amino acid levels in three phases of harvesting straw mushrooms, namely: the egg phase, the bud phase and the adult phase, by using High Performance Liquid Chromatography which aims to determine the harvesting phase with the highest glutamic acid content. The test results of amino acid levels showed the adult phase contained the highest glutamic acid levels of 49.08 mg/g. Furthermore, the manufacture of straw mushroom flour was performed with temperature variations of 60° C and 70° C and drying times of 6, 7 and 8 hours. Then the flavoring formulation was completed  by mixing mushroom flour and other dry additives namely shallots, garlic, white pepper, tapioca flour, salt and sugar. The resulting flavoring test is conducted using a description test by assessing the sensory properties of natural flavorings, namely color, aroma, taste and texture. Based on a panelist rating, F2 (60°C, 7 hours) has the best score for color (3.88) and aroma (3.32). F5 (70°C, 7 hours) has the best score for taste (3.24) and F1 (60°C, 6 hours) has the best score for texture (2.08). The conclusion of  this study is that mushrooms have a very high potential to be deformalized into natural flavorings, as well as the natural flavoring quality parameters of mushrooms is influenced significantly by temperature parameters and drying time

Buku ini merupakan penjabaran hasil-hasil penelitian tentang sintesa membranpoliuretan dari berbagai bahan alam Aceh, khususnya minyak nabati dan rumput laut, yang sebagian besar didanai oleh Kemenristek-Dikti.