The Effectiveness of Physical and Alkali Hydrothermal Pretreatment in Improving Enzyme Susceptibility of Sweet Sorghum Bagasse

Sweet sorghum bagasse (SSB) obtained after juice extraction is a potential feedstock for fermentable sugars production that can be further fermented to different kinds of products, such as ethanol or lactic acid. The proper particle size resulted from phsyical pretreatment and different pretreatment processes including water, alkali, hydrothermal, and alkali hydrothermal for improving enzyme susceptibility of SSB have been investigated. After grinding to particle sizes of 420 ?m the sweet sorghum bagasse was washed to eliminate residual soluble sugars present in the bagasse. Dosages of cellulase enzyme used in saccharification were 60 and 100 FPU/g substrate, respectively. The results showed that SSB with particle sizes of 250-420 ?m had the highest cellulose (38.33%) and hemicellulose content (31.80%). Although the yield of reducing sugar of 250-420 ?m size particles was lower than that of smaller particle (<250 ?m), the former was more economical in the energy consumption for milling process. The yields of reducing sugar obtained from enzymatic hydrolysis of alkali hydrothermal pretreated sweet sorghum bagasse were 1.5 and 0.5 times higher than that from untreated sweet sorghum bagasse at enzyme loading of 100 and 60 FPU/g substrate, respectively. Furthermore, alkali hydrothermal pretreatment was able to remove as much as 85% of lignin. Morphological analysis using SEM (Scanning Electron Microscope) showed that samples treated with alkali hydrothermal have more pores and distorted bundles than that of untreated sweet sorghum bagasse. Meanwhile, XRD (X-ray diffraction) analysis showed that pretreated samples had a higher crystallinity and smaller crystallite size than untreated sweet sorghum bagasse, which might be due to removal of amorphous lignin components

The effect of alkaline-autoclaving delignification on chemical component changes of sugarcane trash

Abstract Sugarcane trash (ST) is lignocellulosic biomass that available abundantly during the sugarcane is harvested as a side product of sugarcane plantation. Several research groups have already reported their ST delignification. However, there is still needs to find a suitable delignification technique for improving recovery of cellulose and eliminate lignin and hemicellulose from a complex structure of ST. One of the methods for delignification is used alkaline with a high temperature. Hence, the research aim is to investigate the effect of alkaline-autoclaving delignification method on chemical component changes of ST. The different sample of ST including washing process and microwave-assisted maleic acid pretreatment prior to the delignification process with 2% NaOH combine with autoclaving in 121°C temperature was used in this study compare with the initial sample. The chemical composition changes in pretreated solid fractions and reducing sugar in pretreated liquid were analyzed. The functional properties were also analyzed using Fourier Transform Infrared (FTIR). The results showed that microwave-assisted maleic acid pretreatment before delignification was the effective treatment in this study to eliminate lignin (88.11%) and hemicellulose (44.07%) and cellulose recovery (78.40%) than that other treatment. Besides, the reducing sugar obtained from microwave-assisted maleic acid pretreatment 3.2 times and 3.6 times higher than that initial biomass and washing treatment, respectively. The FTIR spectra showed that washing treatment affects increasing absorbance of hydroxyl group while the maleic acid pretreatment was also increasing absorbance of carbonyl and the aromatic group that is a feature of lignin compound.</jats:p

Preparation of Starch Phosphate Microparticle Derived from Cassava Starch

Abstract Starch is a vital ingredient that is frequently utilized in the culinary and pharmaceutical industries. However, native starch has drawbacks, namely low solubility and intolerance with extreme pH and temperature treatments. Therefore, the starch needs to be modified. Starch phosphate is one of chemical modification technique for starch that used a cross-linking agent such as sodium trimethaphosphate (STMP), sodium tripolyphosphate (STPP) or phosphate chloride (PCl3). This research aims to prepare the microparticles of modified starch from water in oil microemulsion to be applied as a drug delivery matrix. Starch phosphate was modified with a cross-linking method using sodium trimetaphosphate (STMP). The starch used was Cassava starch. Water in oil microemulsion was made with various surfactant compositions as emulsifiers according to Hydrophilic-Lipophilic Balance (HLB) variations values (4.5; 5.0; 5.5; 6.0) and sonication time 30 minutes. The solubility, swelling, and other physicochemical properties of phosphate starch were investigated. Additionally, the functional group analysis used Fourier Transform Infrared Spectroscopy (FTIR) and size particle analysis was performed using Particle Size Analysis (PSA). The result of the FTIR analysis confirmed that the presence of a phosphate groups in the modified starch has been found. The addition of cosurfactants and sonication treatment affected the characteristics of starch microparticles, the higher the HLB value and the addition of cosurfactants reduced the size of starch microparticles.</jats:p

Characteristics of bioplastic made from modified cassava starch with addition of polyvinyl alcohol

Abstract Food packaging plastic from petroleum-based sources can be a problem to the environment due to its non-biodegradability. The development of bioplastic from modified cassava-starch will be an alternative to overcome that problem. Since starch-based bioplastic usually has low mechanical strength and damage if exposed to water, it’s modification with polyvinyl alcohol (PVA) and citric acid is necessary. Bioplastics are made by heating a solution of modified cassava starch at 75 °C for 1 hour. After starch solution was gelatinized, glycerol (5% based on starch weight) was added, and then PVA solution (25, 50, 100% based on starch weight) was inserted gradually. While stirring was continued, citric acid (5% based on starch weight) was added into the solution. The bioplastic solution was then poured into a 20 × 20 cm acrylic sheet and cooled at room temperature for 3 days, so that the bioplastic sheet was ready for mechanical strength test (ASTM D 882-75b Tensile Properties of Thin Plastic Sheeting) and for thermal properties test with Thermo Gravimetric Analyzer. The results suggested that the addition of 25% polyvinyl alcohol (PVA) into bioplastic made from modified cassava starch produced bioplastic with higher tensile strength compare to that without PVA addition. On the other hand, the addition of 100% PVA could slightly increase bioplastic elongation. The decomposition temperature of bioplastic made from modified cassava starch with 50% PVA was higher than that of the bioplastic without PVA addition, indicated that bioplastic with 50% PVA was more thermally stable.</jats:p

Effect of different amount of cross-linker and catalyst on modified cassava towards its chemical characteristic

Abstract The experimental works involved preparing modified cassava using cross-linker sodium trimethyl phosphate (STMP) and catalyst (sodium chloride) towards its chemical characteristic. In this study, the number of cross-linker and catalyst were varied to determine the effect of each amount of cross-linker and catalyst towards the value of solubility, swelling power, freeze-thaw, and FTIR analysis. Their structural and functional properties were also characterized by Fourier Transform Infrared (FTIR). This study found that the properties of modified cassava containing 2% (w/w) of the catalyst were less effective than the modified cassava comprised of 4% (w/w) sodium chloride. The 2% (w/w) content of cross-linker in the modified cassava model was the best amount of STMP to be used in this process.</jats:p

Investigation of eco-friendly plywood bonded with citric acid – starch based adhesive

Abstract Concerning the environmental issues, the eco-friendly panel product has been developed by using natural based adhesive to ensure safe product application for human health. In this study, Paraserienthes falcataria veneer and citric acid – starch were used in the manufacturing of plywood. The 30 wt% concentration of citric acid – starch-based adhesive was prepared and it was spread to each veneer with 150 g/m2 of glue spread. The plywood was constructed by 3 layers of veneers. The dimension of each veneer was 30 × 30 × 0.2 (cm). The effect of composition ratio between citric acid (CA) and starch (St) as natural sources of adhesive on delamination and shear strength of the plywood was investigated. The plywood was produced under pressing conditions of 180°C for 10 min with 5 MPa of pressure. The variation of compositions ratio (CA:St) were 90:10, 80:20, 70:30, 60:40, 50:50. The research results showed that the plywood with 50 wt% additional of starch had the lowest delamination and highest shear strength. The shear strength of plywood satisfied Standard National Indonesia (SNI) of plywood for general use. Infrared (IR) spectral analysis demonstrated the presence of ester linkage, indicating that the carboxyl groups of citric acid reacted with the hydroxyl groups of the wood veneer. Therefore, 50:50 of composition ration between CA and St was effective composition ratio in the manufacturing of eco-friendly plywood.</jats:p

Study on the existence and characteristics of Sonokeling (Dalbergia latifolia Roxb) as an Appendix II CITES Wood

Abstract Sonokeling (Dalbergia latifolia Roxb) stands are widely lost throughout the world. Sonokeling is currently classified as an Appendix II CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) wood. Therefore, a study on the existence and characteristics of Sonokeling were expected to contribute in providing population data and basic properties of the wood. Exploration was conducted in Plot No. 25, KPH (Forest Management Unit) Gundih, Perum Perhutani Cepu, Central Java. Sonokeling stands have been planted since 1975 (more than 40 years-old) in an area of 54.20 ha, which was not productive for Teak and mixed with Mahogany. Sample was taken from upper part of stem with around 30 cm in diameter and 30 cm in length. The sample was further cutted into 2 x 2 x 2 cm for physical, 30 x 2 x 2 cm for Modulus of Elasticity (MOE) and Modulus of Rupture (MOR), and 4 x 2 x 2 cm for Compression Strength Parallel to the Grain (CSPG) tests. The results showed that specific gravity of sapwood dan heartwood were 0.79 and 0.82, respectively. The average values of MOE, MOR, and CSPG were 117,722, 1122.19, and 1022.93 kgf/cm2, respectively. Therefore, Sonokeling can be classified into Strength Class II.</jats:p

Karakteristik Sifat Mekanik Bioplastik Pati Singkong/pva dengan Penambahan Pulp Tandan Kosong Kelapa Sawit dan Asam Sitrat Teraktivasi

Bioplastik pati singkong telah banyak dilirik sebagai alternatif pengganti plastik non-degradasi. Namun sifat mekanik yang rendah mengharuskan dilakukannya penambahan bahan adiktif seperti polivinil alkohol (PVA) dan dimodifikasi dengan penambahan pulp tandan kosong kelapa sawit (TKKS) maupun dengan asam sitrat teraktivasi (AS). Komposisi optimum bioplastik terplastisasi/ PVA yang didapat yaitu sebanyak 5,5 gram pati singkong, 0,275 gram gliserol, dan 5,5 gram PVA. Pada pembuatannya pati singkong dengan bahan aditif lainnya dicampur pada suhu 75 oC dan dituangkan pada cetakkan, kemudian dikeringan pada suhu ruang. Nilai kuat tarik dan presentase elongasi dilihat sebagai indikasi sifat mekanik. Pada penelitian ini dihasilkan penambahan komposisi 0,055 gram TKKS menghasilkan kuat tarik 14,248 N/mm2 dan presentase elongasi sebesar 29,596% dibandingkan dengan penambahan AS teraktivasi sebanyak 0,825 gram dengan nilai kuat tarik 14,512 N/mm2 dan presentase elongasi sebesar 16,932%. Gugus fungsi O–H, C–H, C=O, dan C–O mengindikasikan interaksi komposit bioplastik yang terkonfirmasi menggunakan spektroskopi FTIR. Menurut tes differential scanning colorimetry (DSC) ditunjukkan adanya puncak endotermik yang merupakan kondisi peleburan dari pengaruh interaksi komposisi dalam bioplastik selama proses pemanasan. Dari hasil penelitian membuktikan bahwa bioplastik terplastisasi/ PVA dengan penambahan TKKS mampu meningkatkan sifat mekanik dan dapat digunakan sebagai acuan pembuatan bioplastik, khususnya sebagai kemasan