Wheat bran as a by-product of milling contain various compounds such as PENTOSANS which have health promoting effects and functinal properties in industrial applications. In this study the extraction yield of PENTOSANS by hot water 80oC, 0. 01 mM sodium hydroxide and 2% alkaline hydrogen peroxide solutions as the conventional methods for pentosan extraction was evaluated. Then, the effects of pretreatments such as cellulase, ultrasound, autoclave and microwave in the presence of sodium hydroxide and water to increase the pentosan extraction yield were studied. Finally, in order to increase the extraction yield of the PENTOSANS, pretreatments with the highest extraction yield (sonication, cellulase enzyme, hot water, sodium hydroxide, hydrogen peroxide) were evaluated as combined treatments. The results showed that the purity of PENTOSANS extracted with sodium hydroxide was significantly higher than the hot water and hydrogen peroxide solution (p<0. 05). Also, among the pretreatments of cellulase enzyme, ultrasound, autoclave and microwave in presence of water or sodium hydroxide, the combination of cellulase-sodium hydroxide and ultrasound-sodium hydroxide treatments resulted in the higher yields. The combined treatment of hot water (80oC)+cellulase enzyme+(0. 1%)+ultrasound power (560 w, 2 minutes) and the combined treatment of hot water (80oC)+hydrogen peroxide (4%, pH=11. 5) were identified respectively as the best combination factors to maximize extraction yield and PENTOSANS purity from wheat bran.

The influence of pulping temperature and time on strength properties of bagasse soda pulp was investigated. Two cooking temperatures (175oC, 185oC) and three cooking times (20, 30, 40 minutes) were selected .The other variables were kept constant at 18 % NaOH and l/w=8. Tensile strength, tear strength index and folding endurance of hand sheets measured. Factorial experiment and randomized block design was used for statistical analysis and DMRT was used for grouping the means. The results indicate that, application of intermediate cooking intensity produced better pulp than more intense pulping at highest pulping time and temperature. However, more intense pulping produced better folding endurance and pulp prepared at 30 minutes cooking time showed better folding endurance than pulp produced at 20 minutes. The highest tear index was obtain at 185oC and 20minutes and lowest at 185oC and 40 minutes. Results indicate that undamaged fibers will product highest tear index. The highest folding endurance was produced at 175oC and 30 minutes and the lowest at 185oC and 30 minutes. Increasing pulping time reduced tensile index and the highest and lowest tensile index obtained at 20 and 40 minutes pulping time respectively.

The influence of pulping temperature, time and alkali charge on residual lignin and viscosity of soda pulp produced from bagasse was investigated. Two pulping temperatures (175oC and 185oC), three pulping times (20, 30 and 40 minutes) and three alkali charges (14, 16, 18% NaOH, OD basis) were used. Factorial experiment based on randomized block design was applied to analyze the effect of pulping variables on total yield, accepted yield, PENTOSANS content, viscosity and kappa number of the pulps. The results showed that higher intensity of pulping reduced both total yield and kappa number. At 175oC pulping temperature, increasing pulping time and alkali charge reduced PENTOSANS content and viscosity, but the reduction of these properties was severe at pulping temperature of 185oC. Higher pulping temperature and time reduced pH of black liquor, which indicates consumption of more alkali during pulping. At milder condition of pulping higher pulp viscosity and PENTOSANS were measured and at severe pulping condition, both properties were reduced which indicates the degradation of carbohydrates especially cellulose. The measured viscosity of pulps produced at 175oC and 185oC were 11.73 and 11.34 cps, respectively, and the related values for pulps produced at 20, 30 and 40 minutes pulping time were respectively 11.78, 11.57 and 11.24 cps. The results showed that pulping time and temperature are the most influential factors on carbohydrate degradation and the influence of alkali charge is not as severe as pulping time and temperature.

The main natural source of PENTOSANS is lignocellulose that exists in biomass. PENTOSANS are hydrolyzed to pentoses in dilute mineral acid hydrolysis. Product of pentoses dehydrolysis is furfural. It can also be produced from different fruit shells as agricultural residues. The pistachio green hulls (PGH) from Pistachio vera as agricultural residues are abundant and low-cost lignocellollosic material and they have good potential for furfural production. In this study, the factors affecting on acid-hydrolysis of PGH such as reaction temperature (from 425 to 545 K), sulfuric acid concentration (from 0.5 to 4.0 mol/l) and reaction times (from 30 to 600 s) have been investigated. The reaction yields have been obtained on the basis of lignocellulose, pentoses and furfural.