Harsh acid hydrolysis is a conventional method for producing nanocrystalline cellulose (CNC), but a more environmentally friendly alternative should be developed. Therefore, this study aimed to investigate the performance of the combined hydrolysis method in the CNC isolation process to improve yield, crystallinity index, and particle size. The conditions of the combined hydrolysis process were examined, specifically the concentration of endoglucanase enzyme (Endo-1,4-β-glucanase (EC. 3.2.1.4)) and the duration of enzymatic hydrolysis. Endoglucanase enzyme concentration was 20 - 100 µL, and hydrolysis time was 12 - 60 h. The results showed that the combined hydrolysis method using enzyme and acid significantly affected the increase in crystalline yield, crystallinity index, and reduced the average crystal size. This process started with cellulose hydrolysis using endoglucanase enzyme with a concentration of 40 µL for 24 h, followed by sulfuric-acid hydrolysis at a concentration of 20% at 40 °C for 30 min. The method produced the highest crystalline yield of 99.10%, crystallinity index 78.13%, average crystal size 20.94 nm, and average particle size of 64.01 nm. FTIR analysis showed that the combined hydrolysis process does not affect the crystalline structure of cellulose, while SEM studies showed a more open and fibrillated appearance because of efficient removal of amorphous areas. Overall, combined enzymatic-chemical hydrolysis produced CNC with high crystallinity, high yield, and smaller particle size, indicating its potential as a biopolymer for food packaging applications. HIGHLIGHTS The combined hydrolysis method improves the crystalline yield (99.10%) and crystallinity index (78.13%) of CNC. The combined hydrolysis method can reduce the use of sulfuric acid. The combined hydrolysis method produces CNC with good characteristics, namely a smaller average crystal size (64.01 nm) and a higher WI value (72.67%). The zeta potential of CNC has a value of –20.39, showing good dispersion in water. GRAPHICAL ABSTRACT

Mushroom industries produce more than 200 million tons of spent mushroom substrate (SMS) per year that is landfilled or used as fertilizers. However, considering the biological degradation of lignocelluloses by filamentous fungi during mushroom cultivation, SMS could be suitable for dry anaerobic digestion (dry-AD) to create a sustainable process by producing biogas and digestate as biofertilizers. In this study, SMS after 3-13 weeks of mushroom cultivation was treated by dry-AD to produce biogas or biomethane and also biofertilizer. The total solids (TS) used were 13% and 21%. The highest methane yield of each TS obtained for 13% TS was at 5-week SMS with 51.99 f 1.2 mL/gVS and for 21% TS was at 9-week SMS with 92.72 f 0.83 mL/gVS. The methane yield from untreated sawdust without fungal cultivation was lower than that of SMS with values of 38.27 f 0.31 mL/gVS for 13% TS and 66.01 f 0.76 mL/gVS for 21% TS in dry-AD. Digestate obtained from dry-AD was found to have a C/N ratio ranging from 16.14 to 23.04 which complies with national regulation for fertilizer.

Filamentous fungi compounds have the ability to bind heavy metals; therefore, it is expected that supplementing cultivation media with essential minerals will lead to mineral accumulation in the fungal biomass. Such biomass can be considered as a food ingredient. This research aimed to investigate the effects of mineral supplementation on fungal growth and sensory properties of food products based on fungal biomass, as well as to determine the optimum supplementation concentration and harvest time. Essential minerals, including iron (Fe), zinc (Zn), and calcium (Ca), were added to the cultivation media of Rhizopus o!igosporus at concentrations of 1.25-11.25, 0.50-5.25, and 50-125 mg/100 mL, respectively. The results showed that the addition of minerals at 3.75, 1.75, and 87.5 mg/100 mL for Fe, Zn, and Ca, respectively, did not significantly affect fungal growth in comparison with the control. Mineral supplementation with Fe, Zn, and Ca successfully increased the mineral content in the fungal biomass by 5, 5, and 13 times that of the biomass cultivated without supplementation, respectively. The mineral content of the biomass reached 28.26, 3.45, and 63.04 mg/100 g after 48 h of incubation for Fe, Zn, and Ca, respectively. The optimum harvesting times for Fe, Zn, and Ca were 48, 24, and 72 h, respectively. The addition of minerals did not affect the overall liking and taste of nugget made from the mineral-enriched fungal biomass. The Fourier transform infrared spectroscopy results showed that there was a new peak that represents new complexes between metal ions and functional group of the fungal biomass. This study revealed that cultivation media fortification with minerals offers a viable solution to enhance mineral content, which is often lacking in vegan diets.

OPEFB is a cellulose-rich biomass waste from the palm oil industry that can be further utilized as nanocrystalline cellulose (CNC). One of the methods used for the isolation of crystalline cellulose is acid hydrolysis. Improper hydrolysis process conditions will cause low crystalline yield, crystallinity index, and unsuitable CNC characteristics. This study aimed to determine the influence of temperature, time, and sulfuric acid concentration on the hydrolysis process of OPEFB cellulose, especially on changes in crystalline yield and crystallinity index of CNC. In this study, the hydrolysis process conditions studied were the hydrolysis temperature, hydrolysis time, and sulfuric acid concentration used. The temperature variation used was 30-80°C, hydrolysis time variation was 30-150 minutes, and the sulfuric acid concentration variation was 10-50%. The analyses included crystalline cellulose yield, crystallinity index, and FTIR. High temperature in hydrolysis resulted in high crystallinity index but low crystalline cellulose yield. The longer hydrolysis time caused a decrease in the yield and crystallinity index of crystalline cellulose. High concentration of sulfuric acid resulted in low crystalline yield, but high crystallinity index. The highest yield of 93.53% was obtained at a low concentration of 20% at 40°C for 30 minutes.

Durian (Durio zibethinus) rind is fruit waste and can be used as a source of pectin. This study aimed to optimize the pectin extraction process using the ultrasound-assisted extraction (UAE) method and evaluate its physicochemical properties. Initially, influencing factors in UAE, such as solvent type (HCl, citric acid, acetic acid, and n-hexane), extraction time (10, 15, 20, 25, and 30 minutes), extraction temperature (40, 50, 60, 70, and 80 degrees C ), sample:solvent ratio (1: 14,1: 17,1: 20,1: 23, and 1: 26 g/mL), duty of cycle (20, 40, 60, 80, and 100%), and amplitude (20, 40, 60, 80, and 100%) were evaluated. Using central composite design (CCD), a temperature of 74 degrees C and sample:solvent ratio of 1 : 20 g/mL were determined as optimum conditions with an estimated pectin yield of 6.07%. This value is in accordance with the experimental result of 6.12%. Extraction with UAE resulted in a higher pectin yield compared to the conventional extraction method using a water bath shaker. The pectin had a degree of esterification (DE) of 44.35%, a moisture content of 4.34%, and an ash content of 1.08%. The FTIR spectra proved the presence of functional groups in pectin, the XRD patterns suggested the structure was more amorphous than crystalline, and SEM showed a smooth pectin surface.

Sodium metasilicate (SMS) tended to agglomerate during glycerolysis reactions in high shear compartment reactors (HSCR), hindering triacylglycerol (TAG) conversion. Therefore, the aim was to evaluate the SMS-magnesium oxide (MgO) blend as a heterogeneous catalyst for glycerolysis reactions. Various SMS-MgO ratios (ranging from 2.5:1 to 10.0:1) were evaluated. The results demonstrated that increasing MgO in the blend reduced catalyst basicity and minimized O-Si-O groups and catalyst crystallinity, preventing clumping and increasing catalyst surface area. The SMS-MgO 5.0:1 blend exhibited the smallest pore size (<2 nm) with a surface area of 4.22 m(2) .(-1)( g) and basicity of 11.59 +/- 0.115 mmol . g(-1). This blend achieved the highest TAG conversion of 53.98%, with a MAG content of 16.86 +/- 0.528% when it was performed at 120 degrees C with an agitator speed of 2,000 rpm for 6 h. Thus, the SMS-MgO 5.0:1 blend shows promise as a heterogeneous catalyst in glycerolysis reaction in HSCR, hindering agglomeration and enhancing surface area.

This study aimed to obtain the best characteristics of a product containing a mixture of high mono- and diacylglycerol (MDAG) from a palm olein and coconut oil blend through glycerolysis- interesterification using a high shear reactor. The most optimum reaction was performed at a relatively low temperature (120 °C), 3% NaOH as a catalyst, a 12% molecular sieve, and an agitating speed of 2000 rpm. The evaluated factors were palm olein: coconut oil ratios (70:30, 60:40, 50:50, 40:60, and 30:70) and oil: glycerol ratios (1:3, 1:4, 1:5, 1:6, and 1:7). The results showed that palm olein: coconut oil ratio had a significant effect on melting point (MP), slip melting point (SMP), hardness, and emulsion capacity and stability, but it did not have a significant effect on MDAG concentration (P > 0.05). Besides, modifying a high-shear reactor with a vacuum pump and molecular sieve caused a decrease in water content in the system, subsequently reducing free fatty acid (FFA) significantly (P < 0.05). The reaction condition at palm olein: coconut oil ratio of 50:50 and oil: glycerol ratio of 1:5 produced the highest MDAG concentration (58.28%) with FFA, water content, hardness, SMP, MP, emulsion capacity, and emulsion stability about 6.75%, 7.00%, 3.93 N, 33.23 °C, 35.57 °C, 62.66%, and 61.59%, respectively. Thus, glycerolysis-interesterification of palm olein and coconut oil blend in a high shear reactor is a promising alternative to produce a product containing high MDAG with better characteristics at a relatively low temperature. The product can be used for chocolate spread based on its emulsion capacity, stability, and semi-solid hardness.

This study aimed to synthesize structured lipids containing high mono- and diacylglycerol by glycerolysisinteresterification of palm olein and coconut oil blend in two high-shear continuous stirred tank reactors in series. The result showed that various flow rates of 11 mL/min to 23 mL/min did not significantly increase mono- and diacylglycerol concentration, while at a flow rate of 26 mL/min only a low concentration of mono- and diacylglycerol was formed. However, a flow rate 20 mL/min and an agitating speed of 2000 rpm produced mono- and diacylglycerol concentration of 61.7% with the highest productivity of 2.1%/min and a triacylglycerol conversion of 64.6%. The slip melting point, melting point, hardness, emulsion capacity, and stability were 23.77 oC, 30 oC, 14.6 N, 65.15%, and 59.15%, respectively. The product’s solid fat content at 25 oC was lower than cocoa butter. The product contained β’ and β crystals, thus it can be applied as a cocoa butter substitute.

A pretreatment process is needed in the bioconversion of oil palm empty fruit bunch (OPEFB) to remove lignin and to get crystalline cellulose for CNC production. Several pretreatment methods were studied, i.e., pretreatment with 10% NaOH, combination method of 10% NaOH and H2O2 (1.5% and 24%), as well as 10% NaOH and NaClo2 (1.4% and 12%). In the combination method, washing was applied in between processes to reach the pH of +/- 6. The temperature for the pretreatment processes was 70 degrees C. The pH for pretreatment with 10% NaOH was +/- 13, the pH for pretreatment with H2O2 (1.5% and 24%) was +/- 8 and +/- 6, and the pH for pretreatment with NaClO2 (1.4% and 12%) was adjusted to 4. The results showed that the highest lignin removal of 100% and the highest whiteness index were obtained after the combination pretreatment with 10% NaOH and 12% NaClO2. The highest cellulose yield of 65.33% was obtained after pretreatment with 10% NaOH. The combination pretreatment with 10% NaOH and 1.4% NaClO2 produced the highest crystallinity index of 69.35% from the cellulose obtained. The X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy results confirmed the presence of the cellulose obtained. Based on the value of the crystallinity index and considering the values of lignin removal, whiteness index, and cellulose yield, the combination pretreatment with 10% NaOH and 1.4% NaClO2 was selected as the suggested process.

This research studied the conversion of alkaline-pretreated oil palm empty fruit bunch (OPEFB) into volatile fatty acids (VFA) through anaerobic fermentation (AF). In AF, the methanogens that consume VFAs must be sup-pressed to increase the accumulated VFA as an intermediate product of AF. In-depth research has not been conducted on the effects of temperature and micro aeration to maximize the VFA accumulation. To investigate the temperature effect, the experiment was run at mesophilic (RM) and thermophilic conditions (RT). The impact of the micro aeration dose was studied in the thermophilic reactor set to the ORP-50 mV (RTM-50) and ORP-150 mV (RTM-150). The experimental data were fitted to the Anaerobic Digestion Model 1 (ADM 1) using AQUASIM & REG;. The khyd.ch value of the RT reactor is higher than that of the RM, suggesting that high temperatures encourage hydrolysis and enhance hydrolase activity. Based on the simulation results, RT reactors without micro -aeration had a substantially higher specific growth rate of methanogens compared to RM. Therefore, micro aeration should be applied in RT to suppress the potentially faster growth of methanogen bacteria at elevated temperature. The result of this study indicated that both temperature and micro-aeration were important process variable to be further optimized to make VFAs production from OPEFB attractive.

This paper presents an overview of the concept of biorefinery based on anaerobic digestion (AD) process that converts various wastes from easily degradable to challenging materials as well as carbon dioxide into many valuable products. Anaerobic digestion produces volatile fatty acids, biohydrogen, biogas, and biosludge. Factors that affect the production process, the reactor system, and the downstream process to obtain the desired product are discussed. Future applications of the AD products and their derivatives as biofuels, biochemicals, biomaterials, and biofertilizer as well as the market size are presented. Implementation of AD biorefinery is potentially accelerate the achievement of sustainable development goals, especially in the areas of clean water and sanitation, affordable and clean energy, and climate change.

The cross-linking agent plays an important role in bioplastic mechanical properties. This study aimed to determine the effect of Sodium Hyaluronate (SoHA) as a synthetic cross-linking agent and the addition of Nyamplung Cake Extract (NCE) as an antimicrobial agent in the manufacture of bioplastic with hydroxypropyl starch (HPS) as based ingredient using the thermo-compression method. The novelty of the study was thiocyanate (SCN) formation in zone 3 (2161.66-2162.02/cm) and cyanate (C-N=O) in zone 6 (1,411.57 - 1,412.61/cm) of (1, 2 and 3%) SoHA bioplastic and cyanate formation in zone 6 and 7 (1,411.37 - 1,558.59/cm) of (1, 2 and 3%) SoHA – 20% NCE combined bioplastic originating from acetanilide group in SoHA and amide group in NCE. The formation of SCN and C-N=O in 2 and 3% SoHA bioplastic improved its sensitivity against gram-positive bacteria (Staphylococcus aureus) indicated by 0.6 mm and 0.45 mm inhibition zone, respectively. C-N=O formed in (1, 2 and 3%) SoHA – 20% NCE combined with bioplastic had 3.25 mm average inhibition zone against gram-positive bacteria (S. aureus), 2.75 mm against gram-negative bacteria (Escherichia coli), and 0.71 mm against fungi (Aspergillus niger). The analysis of mechanical properties showed that an addition of 3% SoHA was able to increase tensile strength and modulus of elasticity while reducing elongation, water solubility and water vapor permeability. Addition of (1, 2 and 3%) SoHA – 20% NCE resulted in a reverse effect. Keywords: acetanilide, amide, cross-linking agent, cyanate, thiocyanate

A carcinogenic 3-monochloropropane 1, 2 diol ester (3-MCPD ester) can be formed during processing crude palm oil (CPO). Chlorine is one of the precursors for the formation of 3-MCPD esters. This study aimed to optimize the bleaching conditions using zeolite-Fe for reducing chlorine concentration by the Response Surface Methodology (RSM) and further evaluate the characteristics of the bleached CPO. Factors such as bleaching time, zeolite-Fe concentration, and bleaching temperature were evaluated and further optimized. The results showed that Fe in the modified zeolite-Fe increased about 71.89% compared to natural zeolite. Zeolite-Fe concentration, bleaching time, and bleaching temperature had a significant effect on chlorine adsorption. The optimum bleaching process was obtained at a zeolite-Fe concentration of 5% (w/w) and bleaching temperature of 80 °C for 30 minutes. Bleached CPO had a chlorine concentration of 25 ± 1 ppb, carotenoid of 467.70 ± 13.71 ppm, and a DOBI (Deterioration Of Bleachability Index) value of 2.17 ± 0.01 R.

The fermentation of fruit processing residuals (FPRs) with filamentous fungi can provide protein-rich food products. However, FPRs that contain bioactive compounds with antimicrobial properties present a major challenge. In this work, the resistance of two edible filamentous fungi, Rhizopus oligosporus and Neurospora intermedia, to 10 typically inhibiting bioactive compounds available in FPRs (epicatechin, quercetin, ellagic acid, betanin, octanol, hexanal, D-limonene, myrcene, car-3-ene, and ascorbic acid) was examined. These compounds' inhibitory and stimulatory effects on fungal growth were examined individually. Three different concentrations (2.4, 24, and 240 mg/L) within the natural concentration range of these compounds in FPRs were tested. These bioactive compounds stimulated the growth yield and glucose consumption rate of R. oligosporus, while there was no increase in the biomass yield of N. intermedia. Ellagic acid caused an up to four-fold increase in the biomass yield of R. oligosporus. In addition, octanol and D-limonene showed antifungal effects against N. intermedia. These results may be helpful in the development of fungus-based novel fermented foods.

The increasing growth of palm oil industry results in an increase in the accumulation of waste generated from the industry, such as oil palm empty fruit bunches (OPEFB). OPEFB is a good source of renewable raw materials if a pretreatment process can overcome the recalcitrance of OPEFB and allows the fractionation of all carbohydrates and lignin. In this work, the effectiveness of organosolv pretreatment to deconstruct OPEFB and to recover high purity of lignin and glucan was studied. The pretreatment experiments were carried out at 210 °C for 90 minutes with a solid to liquid ratio of 1/10. Ethanol 50% (v/v) was used as solvent. The effect of H 2 SO 4 0.07% (w/w) as catalyst was also studied. The results showed that organosolv pretreatment with the addition of acid increased the purity of glucan and lignin by 36 and 5%, respectively. A total of 65% lignin was recovered, which was 3.6 times higher than lignin from pretreatment without acid catalyst. After organosolv pretreatment with an acid catalyst, the crystallinity index (CRI) decreased by 54%, while the decrease in CRI was only 14.4% after pretreatment without an acid catalyst. The water retention value of the pretreated OPEFB with acid catalyst increased by 8%. It can be concluded that organosolv pretreatment using ethanol as a solvent with the addition of acid catalyst succeeded in fractionating OPEFB with high purity and reducing recalcitrant OPEFB.

Abstract Palm oil is one of the leading global commodities, and Indonesia is one of the largest palm oil producers in the world. One of the solid wastes generated from oil palm industrial activities is oil palm empty fruit bunches (OPEFB). The annual accumulation of OPEFB in Indonesia is 126,317.54 tons/year, and it increases with increasing palm oil production. The cellulosic content of OPEFB is a potential substrate for anaerobic digestion to produce volatile fatty acids (VFAs). This study used chemical pretreatment (NaOH 8% w/V) for OPEFB delignification before the anaerobic digestion for VFAs production. Digested cow manure (DCM) was used as the inoculum. Process optimization of producing VFAs is challenging because VFAs act as intermediate products in the metabolic pathway of anaerobic digestion. In general, the temperature can affect the activity of hydrolytic and acidogenic facultative microorganisms. It increases the hydrolysis rate of organic polymers to more soluble forms and improves the performance of anaerobic reactors for the formation of VFAs. This study examines the effect of temperature on the anaerobic digestion process of OPEFB for VFAs production in a batch reactor. The temperature varied in mesophilic (29 °C) and thermophilic (55 °C) conditions. This study showed that anaerobic digestion in the thermophilic conditions produces almost thrice VFAs compared to the mesophilic process. The highest accumulation of VFAs in both reactors occurred on the seventh day, i.e., 3311.57 ± 89 mg.L−1 at ORP -163 ± 16 mV in the thermophilic reactor and 1307 ± 42 mg.L−1 at ORP -224 ± 32 mV in the mesophilic reactor. Acetic acid was the dominant VFA in each reactor. The VFA production in thermophilic reactor (RT) reached 59% of the stoichiometric potential. Although the thermophilic condition improves the VFA yield compared to the mesophilic condition, further study is still needed to increase the VFA production from OPEFB.

In this study, ethanol organosolv treatment of oat husk and the potential effects of phosphoric acid and oxalic acid as alternatives to sulfuric acid were investigated. These acids were determined as effective as sulfuric acid to obtain high quality lignin and glucan and they can be used instead of sulfuric acid in solvent acidification. To determine the purity and recovery of both lignin and glucan, the effects of initial substrate amount, solid-to-liquid ratio, and amount of washing solutions were also examined using a one-factor-at-a-time strategy. Reducing the amount of washing solutions (water, solvent, or both) negatively affected lignin recovery, but it did not affect glucan recovery. The optimum conditions for pretreatment of the oat husk at higher glucan recovery were obtained with 50% aqueous ethanol acidified with oxalic acid at 210 °C for 90 min and solid-to-liquid ratio of 1:2. In the mixture of evaporated glucan-rich and hemicellulose-rich fractions obtained through the optimized condition, 4.62 g/L biomass containing 10.27% protein was produced by the cultivation of Aspergillus oryzae . The fractions obtained from organosolv treatment can be used to obtain value-added products such as biomass production, and thus contributing to a sustainable economy by integrating lignocellulosic substrate residues into the biorefinery.

Raw syngas contains tar contaminants including toluene and naphthalene, which inhibit its conversion to methane. Cell encasement in a hydrophilic reverse membrane bioreactor (RMBR) could protect the cells from hydrophobic contaminants. This study aimed to investigate the inhibition of toluene and naphthalene and the effect of using RMBR. In this work, toluene and naphthalene were added at concentrations of 0.5-1.0 and 0.1-0.2 g/L in batch operation. In continuous operation, concentration of 0-6.44 g/L for toluene and 0-1.28 g/L for naphthalene were studied. The results showed that no inhibition was observed in batch operation for toluene and naphthalene at concentrations up to 1 and 0.2 g/L, respectively. In continuous operation of free cell bioreactors (FCBRs), inhibition of toluene and naphthalene started at 2.05 and 0.63 g/L, respectively. When they were present simultaneously, inhibition of toluene and naphthalene occurred at concentrations of 3.14 and 0.63 g/L, respectively. In continuous RMBRs, no inhibition for toluene and less inhibition for naphthalene were observed, resulting in higher methane production from RMBR than that of FCBR. These results indicated that RMBR system gave a better protection effect against inhibitors compared with FCBR.

Gamping biogas plant was built in 2011 to solve waste problem from GemahRipah fruit market which generate 4-10 tons waste/day.The digester was design for 4 ton/day and produce biogas and electricity.The electricity is used for lighting the shops and the road.For eightyears along the installation, biogas unit has been facilitated with transportation, crusher, anaerobic digester, generator, electricity and sensor unit.All the facilities are purposedto utilize the biogas.Another side product of sludge from digestate as by product is just discharged without any application.Here, we developed zero waste concept to utilize all products of anaerobic digester i.e. biogas to produce electricity and biogas sludge as fertilizer.The liquid fertilizer potentially supports the sustainability of the biogas unit from economic value of vegetable products or liquid fertilizer itself.Biogas produced from fruit waste contains 59% methane and 37% carbon dioxide (average from one year).The cumulative production for a half year monitoring is 650 Nm3 biogas and generate electricity up to 120 kWh.Biogas slurry effluent was fermented for two weeks and directly appliedas fertilizer.The analysis showed it contains C-Organik, N Total, P, K 0.39%, 0.34%, 0.07%, 1.91% respectively.Biogas slurry could support the growth of vegetative phase, while less support for generative phase.

In a circular economy approach, edible filamentous fungi (single cell protein) can be cultivated on volatile fatty acids (VFAs) derived from anaerobic digestion (AD) of organic-rich waste streams. In this study, the effect of pH, concentration/distribution of VFAs, nutrient supplementation, and type of waste on Aspergillus oryzae cultivation on synthetic VFAs, and actual VFAs derived from AD of food waste and cow manure were investigated. The optimal pH for A. oryzae growth on VFAs were 6 and 7 with maximum acetic acid consumption rates of 0.09 g/L. h. The fungus could thrive on high concentrations of acetic (up to 9 g/L) yielding 0.29 g dry biomass/gVFAs(fed). In mixed VFAs cultures, A. oryzae primarily consumed caproic and acetic acids reaching a biomass yield of 0.26 g dry biomass/gVFAs(fed) (containing up to 41% protein). For waste-derived VFAs at pH 6, the fungus successfully consumed 81-100% of caproic, acetic, and butyric acids.