scholarly journals Microwave-assisted enzymatic hydrolysis to produce xylooligosaccharides from rice husk alkali-soluble arabinoxylan

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Wannaporn Klangpetch ◽  
Alisa Pattarapisitporn ◽  
Suphat Phongthai ◽  
Niramon Utama-ang ◽  
Thunnop Laokuldilok ◽  
...  

AbstractThe prebiotic properties of xylooligosaccharides (XOS) and arabino-xylooligosaccharides (AXOS) produced from rice husk (RH) using microwave treatment combined with enzymatic hydrolysis were evaluated. The RH was subjected to microwave pretreatment at 140, 160 and 180 °C for 5, 10 and 15 min to obtain crude arabinoxylan (AX). Increasing microwave pretreatment time increased sugar content. Crude AX was extracted with 2% (w/v) sodium hydroxide at 25 °C for 24 h and used as a substrate for XOS production by commercial xylanases. Results showed that oligosaccharides produced by Pentopan Mono BG and Ultraflo Max provided xylobiose and xylotriose as the main products. AXOS was also present in the oligosaccharides that promoted growth of Lactobacillus spp. and resisted degradation by over 70% after exposure to simulated human digestion.

2021 ◽  
Author(s):  
Wannaporn Klangpetch ◽  
Alisa Pattarapisitporn ◽  
Suphat Phongthai ◽  
Pannapapol Jaichakan

Abstract This study aimed to produce xylooligosaccharide (XOS) and arabino-xylooligosaccharide (AXOS) from rice husk (RH) using microwave treatment combined with enzymatic hydrolysis and evaluate their prebiotic properties. The RH was pretreated by a microwave heating process at 140, 160 and 180°C for 5, 10, and 15 min to obtain crude arabinoxylan (AX). The results emphasized that increasing microwave pretreatment time increased sugar content. The crude AX was then extracted with 2% (w/v) sodium hydroxide at 25°C for 24 h. The obtained AX was then used as a substrate for XOS production by commercial xylanases. The results showed that the oligosaccharide produced by Pentopan Mono BG and Ultraflo Max provided xylobiose and xylotriose as the main products. Interestingly, AXOS was also present in the oligosaccharide product. Furthermore, the oligosaccharides obtained were able to promote the growth of Lactobacillus spp. and to resist degradation more than 70% after exposure to simulated human digestion.


Author(s):  
Alisa Pattarapisitporn ◽  
Nonglak Thiangthong ◽  
Pakorn Inthajak ◽  
Pannapapol Jaichakan ◽  
Wantana Panpa ◽  
...  

Rice straw (RS) is a by-product from rice production process. It is rich in cellulose, hemicellulose and lignin. RS hemicellulose mainly composes of arabinoxylan (AX). This research aimed to investigate the potential of microwave-pretreatment in AX extraction from RS and substrate to produce xylooligosaccharides (XOS) via enzymatic hydrolysis. The extractive-free RS was pretreated by microwave process at 160°C for 5-15 min, then the AX was extracted with 4% sodium hydroxide. The total sugar and reducing sugar content of AX exhibited that increasing microwave-pretreatment time increased the yield of AX. The highest AX content was found at 160°C for 10 min as 7.73%, reducing sugar content of 11.89 mg/g, and total sugar of 165.85 mg/g. The crude AX obtained by microwave-pretreatment was then used as a substrate for XOS production by two commercial xylanases of Pentopan mono BG (BG) and Ultraflo Max (UM), at the enzyme concentration of 50-300 U/g AX (50°C, pH 6.0) for 24 h.The reducing sugar content and sugar profiles were monitored by DNS assay,and thin layer chromatography (TLC) which revealed that BG 50 U/g at 12 h andUM 50 U/g at 24 h showed the promising reducing sugar of 16.4 and 25.44 mg/g,respectively. The composition of XOS derived from RS (RS-XOS) prepared by BGwas xylobiose (X2), xylotriose (X3), xylotretraose (X4), and xylopentaose (X5)while by UM was xylobiose (X2), xylotriose (X3) and xylotretraose (X5). Moreover,XOS produced by BG contained very low amount of xylose (X1). In addition, theRS-XOS could the growth of Lactobacillus brevis greater than commercial XOS.


Author(s):  
Marcin Lukasiewicz ◽  
Anna Osowiec ◽  
Magdalena Marciniak

2018 ◽  
Vol 69 (8) ◽  
pp. 1976-1979
Author(s):  
Ioana Asofiei ◽  
Ioan Calinescu ◽  
Adina Ionuta Gavrila ◽  
Daniel Ighigeanu ◽  
Diana Martin

It was designed and built a laboratory experimental installation (LEI) for the microwave pretreatment of vegetable materials. To study the influence of microwave pretreatment on the total phenolic content (TPC), a conventional extraction of polyphenols from treated and untreated fresh sea buckthorn leaves was performed. For short extraction times, the amount of phenolic compounds was higher for the extracts obtained from treated leaves, but a long pretreatment time (28 s) led to a decrease in TPC. The qualitative analysis showed that the chemical composition is not affected by the microwave pretreatment.


2016 ◽  
Vol 8 (3) ◽  
pp. 274-279 ◽  
Author(s):  
E. M. Podgorbunskikh ◽  
A. L. Bychkov ◽  
O. I. Lomovskii

Author(s):  
Chunsheng Qiu ◽  
Jinxin Zheng ◽  
Chenchen Wang ◽  
Bingbing Wang ◽  
Nannan Liu ◽  
...  

Abstract The migration, transformation and ecological risk of heavy metals (Cr, As, Ni, Cu, Zn, Cd and Pb) in the sewage sludge during the microwave-assisted thermal hydrolysis process were investigated under different temperatures (80 °C, 100 °C, 120 °C, 140 °C, and 160 °C). The potential relationship between the bio-availability of heavy metals and the variables of microwave treatment, including pH, ammonium-nitrogen, soluble chemical oxygen demand, pH, soluble protein, soluble polysaccharide and volatile solid, was also explored. The results showed that the migration of heavy metals between solid-liquid phase mainly depended on the temperature. The percentage of all heavy metals (except Cu) in mobile (acid-soluble/exchangeable and reducible) forms decreased after microwave-assisted thermal hydrolysis treatment. The solubilization of compounds with C = O and O-H accompanied with the generation of organic and inorganic metal halides were also observed in the treated sludge through fourier transform infrared spectroscopy analysis. NH4+-N showed the highest negative correlation to the bio-availability of most heavy metals (except Cu and Cr) with coefficients (absolute value) over 0.87 (P < 0.05). VS showed a positive correlation to the bio-availability of most heavy metals (except Cu). The total potential ecological risk index (RI) decreased by 46.65% after microwave treatment at 160 °C.


Author(s):  
Gwandu AZ ◽  
Farouq AA ◽  
Baki AS ◽  
Peni DN

This study was based on the production of bioethanol as an alternative source of fuel using rice and millet husks. Proximate, elemental and thermogravimetric analysis (TGA) were conducted of the biomass. The proximate analysis revealed that millet husk had the highest moisture content of 26.67±0.58% when compared with rice husk 8.17±0.29%. The TGA of rice husk had a high endset temperature of 355.510C and a weight loss of -48.23%, millet husk had low endset temperature of 349.210C and a weight loss of -44.25%. When thirty grams (30g) of the substrates was used, rice husk revealed the highest reducing sugar content of 2.59±1.24mol/dm3 when compared to millet husk that had 1.63±0.68 mol/dm3. Rice husk indicated low yield after 7 days of fermentation period but showed a significantly high yield in the volume of ethanol produced 68.67±17.69g/l and millet husk had a yield of 79.80±0.93g/l. This indicated that both rice and millet husks were potent for bioethanol production with millet husk having the highest yield.


Sign in / Sign up

Export Citation Format

Share Document