Evaluation of antioxidant activity of dilute acid hydrolysate of wheat straw during xylose production

Abstract

Wheat straw, a lignocellulosic waste material, can be used as a raw material for the production of highvalue\ud products such as xylose for xylitol production or phenolic compounds that have antioxidant activity.\ud There is a growing interest in the use of lignocellulosic wastes for conversion into various chemicals\ud because of their low cost and the fact that they are renewable and abundant. The objective of this study\ud was to determine the effects of H2SO4 concentration, temperature and reaction time on the production\ud of sugars (xylose) and phenolic compounds. Response surface methodology (RSM) was used to optimize\ud the hydrolysis process to obtain high xylose yield and phenolic compounds. The optimum reaction temperature,\ud reaction time and acid concentration were 120 ◦C, 45 min and 4.7% respectively. Under these\ud conditions, xylose and phenolic of the hydrolysate was found to be 0.16 g/g-wheat straw and 0.014 g-gallic\ud acid/g-wheat straw, respectively

The Effect of Severity Factor on the Release of Xylose and Phenolics from Rice Husk and Rice Straw

“…However, increasing pretreatment SF also increases degradation of sugars to various by-products (furfural, phenolic…) which strongly affect the microbial metabolism during xylitol production. The overall xylose yields and phenolic contents of the dilute acid hydrolysates of RH and RS were found to be similar to those obtained from previous studies on the production of xylose [19,22] and phenolic compounds [27] from different lignocellulosic materials through acid hydrolysis.…”

“…Due to its amorphous structure, the hemicellulosic fraction of lignocellulosic materials can be easily hydrolyzed by dilute acid treatment, whereas the cellulosic and lignin fractions remain unaltered. Several researchers have studied the dilute acid hydrolysis of different lignocellulosic wastes, such as corn stover [11,12], eucalyptus residue [13], palm waste [14], rapeseed straw [10,15,16], barley straw [10,17,18], wheat straw [19,20], rice husk [2,21] and rice straw [10,[22][23][24][25][26]. However, there are several disadvantages of the dilute acid hydrolysis of these lignocellulosic wastes, such as the production of inhibitors, including acetic acid, furfural [9,17] and phenolics from lignin degradation products [19] and the corrosion of equipment.…”

“…The SF combines the experimental effects of temperature, residence time and acid concentration into one factor [28] and has been previously studied in the dilute acid pretreatment of corn stover [11,12], rapeseed straw [10,16], rice straw [10,23], barley straw [10,17] and wheat straw [19,28].…”

“…The severity factor is an important parameter that affects the production of xylose, other sugars and by products (acetic acid, sugar and lignin degradation products) [14,19]. Therefore, it is necessary to run the hydrolysis reaction at less severe conditions where xylose yield is maximum but by products and other sugars concentrations, that strongly affect the microbial metabolism during xylose fermentation, are minimum.…”

Physicochemical Characteristics, Antioxidant Activity, Organic Acid and Sugar Contents of 12 Sweet Cherry (Prunus Avium L.) Cultivars Grown in Turkey

“…The FRAP analysis was carried out as described in Akpinar and others () and Demir and others (). A 0.1 mL of cherry juice diluted with ethanol (pure) and mixed with 2.9 mL of FRAP reagent prepared by mixing of 20 mmol/L FeCl 3 ·6H 2 O, 10 mmol/L TPTZ, and 300 mM acetate buffer (pH 3.6).…”