This study aimed to develop paper packaging from rice straw fibers with its function as antibacterial activity obtained from pomelo (Citrus maxima) peels. Paper with ca. 106.42 g/m2 basis weight, 0.34 mm thickness, 34.15 % brightness and 78.7 N.m/g tensile index was prepared from rice straw fibers and pulps. Bioactive compounds of crude pomelo peels extracted using maceration technique with 75% (v/v) ethanol were coated onto rice straw papers at concentration of 10, 15 and 20 % (w/v). The coated papers had similar thickness, and slightly lower tensile index and brightness as compared to those of control papers. Scanning electron microscopy confirmed the changes of surface and cross-section structures of coated and uncoated papers. The rice straw coated papers had relatively greater barrier property to prevent water absorption. In addition, the coated papers with pomelo peel extract showed significant antibacterial activity against food pathogenic bacteria, including Staphylococcus aureus, Bacillus cereus and Escherichia coli. This study reveals the benefits of natural by-products as a potential material for active packaging.

This study aimed to develop active paper from rice straw fibers with its function as antibacterial activity obtained from longan (Dimocarpus longan) peels. The morphology and mechanical properties of fibers of rice straw were examined as quality parameters for paper production. Rice straw paper (RSP) with basis weight ca 106.42 g/m2, 0.34 mm thickness, 34.15% brightness, and 32.26 N·m/g tensile index was successfully prepared from fibers and pulps without chemical bleaching process. Bioactive compounds of longan peels were extracted using maceration technique with a mixture of ethanol-water, and subsequently coated onto RSP at concentration of 10%, 15% and 20% (w/v). Fourier transform infrared (FTIR) spectroscopic analysis demonstrated the functional groups of phytochemicals in the peel extract. The results of physical properties showed that the coated RSP had similar thickness and tensile index, but had lower brightness compared to control papers. Scanning electron microscopy (SEM) confirmed the significantly different of surface and cross-section structures between coated and uncoated RSP. The coated RSP had relatively greater barrier properties to prevent water absorption. In addition, the RSP coated with longan peel extracts showed significant antibacterial activity against foodborne bacteria, Staphylococcus aureus and Bacillus cereus. This study reveals the benefits of natural byproducts as potential materials for active packaging prepared by environmentally friendly processes.

This is the first report of the potential of Acacia fast growing trees in Thailand, A. mangium and the Acacia hybrid (A. mangium x A. auriculiformis), as raw material for ethanol production through a simultaneous saccharification and fermentation process by Saccharomyces cerevisiae TISTR 5339. Alkaline pulping was applied as the pretreatment process. Optimization of ethanol production was studied using response surface methodology based on central composite design. The optimized conditions of 100 g/L solid loading and an A600 of S. cerevisiae TISTR 5339 of 2 gave observed values of ethanol production of 35.7 and 27.3 g/L, which corresponded with the predicted values of 32.32 and 26.37g/L from A. mangium and A. hybrid, respectively. This condition was then used for up-scaling in a 10-L stirred bioreactor. The improved maximum ethanol concentrations of 37.84 and 36.52 g/L were obtained from A. mangium and Acacia hybrid, respectively, within 96 h of cultivation at 30 °C and no aeration rate. Keywords INTRODUCTIONWith the depletion of the world's petroleum, alternative non-petroleum-based sources of energy are being looked at with greater interest. Many countries have begun focusing on renewable resources for production of ethanol-based fuels. Lignocellulosic biomass from woody plants has the potential to become a major source of fermentable sugars for the production of ethanol because trees are the most abundant source of biomass. Thus, lignocellulosic biomass has been considered a new resource for ethanol production.Because of its chemical composition, lignocellulosic biomass is very different from types of biomass that have large content of sugars or starch, as is customarily used in the biofuel industry. The structure of these former materials, mainly composed by cellulose, hemicellulose, and lignin, requires the process for biofuels production to be adjusted for each type of biomass, according to their component characteristics. Thus, pretreatment has been recognized as a necessary upstream process to improve the formation of sugars for downstream microbial and enzymatic processing.Different kind of pretreatment methods, under a large variety of conditions, have been studied to improve the fermentability and digestibility. Mechanical size reduction is a physical pretreatment to increase enzyme-accessible surface areas (Zhu et al. 2009). In addition to these other pretreatment options, steam explosion is a technique based on PEER-REVIEWED ARTICLE bioresources.com Boondaeng et al. (2015). "Ethanol from Acacia," BioResources 10(2), 3154-3168. 3155 subjecting the biomass to pressurized steam for a short duration of time and then suddenly depressurizing the system. Due to the explosive decomposition, the fibers are separated and changes to the microstructure are brought about by the suddenly reduced pressure (Brodeur et al. 2011). The treatments result in increasing cellulose digestibility of pretreated biomass and solubilizing a significant portion of the hemicellulosic component (Nibedita et al. 2012). To help wi...

This research aims to use oil palm empty fruit bunch (EFB) fibers to reinforce epoxy resin for bumper beam in cars to replace epoxy/glass fiber composite. EFB fibers were extracted by two methods; chemical method by treating with 10-30% sodium hydroxide (% by weight of fiber) and mechanical method by steam explosion process at 12-20 kgf/cm2 for 5 mins. Then, the obtained fibers were bleached by hydrogen peroxide. The results show that the chemical method can eliminate lignin better than the other and provided stronger fibers. Increasing of alkaline concentration yielded the decrease of lignin content and increase of cellulose content, while no significant difference on fiber size and strength was observed. In steam explosion method, increasing of pressure vapor affected to more dark brown color and disintegrated fibers. Therefore, the optimal method for preparing EFB fibers for reinforcement of epoxy composite was chemical treatment using 30%NaOH, followed by bleaching. Then, the EFB fibers extracted by chemical method at 30%NaOH were used for reinforcing epoxy composite with fiber contents of 0-10%w/w and compared to epoxy/glass fiber composite. The results show that flexural modulus did not increase with increasing fiber content. However, the chemical treated fibers can support composite from falling apart after testing like glass fiber reinforced composite with fiber contents upper than 7.5%w/w. Impact strength and storage modulus of alkaline treated palm fiber reinforced composites increased when fiber content more than 7.5%w/w. Thermal properties of composite, analyzed by DSC and DMTA, shows that the Tg increased with fiber content. Flexural modulus and thermal properties of EFB reinforced epoxy composites provided similar results to glass fiber reinforced composites. Therefore, EFB fiber reinforced epoxy composite could be an alternative green material for bumper beam in automobile.