The potential of walnut shells for production of oligosaccharides by liquid hot water treatment

Küçük Resim Yok

Tarih

2023

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Springer Heidelberg

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

Walnut shell (WS), which is discarded in a large amount, is usually utilized for heating purposes; therefore, obtaining fuctional products can add value to this waste biomass. In this study, xylan was determined as the dominant carbohydrate (18.6% of dry weight) in WS. The potential applicability of liquid hot water (LHW) treatment to WS was investigated in order to solubilize hemicellulose and hydrolyze it into oligomers such as xylooligosaccharide (XOS) as a prebiotic oligosaccharide and recover solid and liquid fractions, which can be raw materials for other value-added products. LHW was applied at different temperatures (170-210 degrees C) for various times (15-120 min), and their effect was combined calculating severity factor (log R-o = 3.39-4.74). The solubilization of biomass was increased (up to 60.9%) with severity. Under optimum conditions (log R-o of 3.95, 190 degrees C-15 min), 81.5% of xylan was hydrolyzed and recovered as mainly XOS (69.8% of xylan), and also xylose and arabinose. The total oligosaccharide (XOS, arabino, gluco- and galacto-oligosaccharides) and monosaccharide (mainly xylose) concentration were 14.3 and 2 g/L, respectively, and by-products did not exceed 1.6 g/L. Moreover, 2.5 mg GAE/mL of total phenolics were obtained at those conditions, whereas that was raised to 3.4 mg GAE/mL at harsher conditions. This study presented that LHW treatment was an eco-friendly alternative method for valorization of WS through production of a liquid with high value-added compounds such as oligosaccharides and solid rich in cellulose and lignin.

Açıklama

Anahtar Kelimeler

Hemicellulose, Liquid Hot Water, Oligosaccharide, Valorization, Walnut Shell

Kaynak

Biomass Conversion and Biorefinery

WoS Q Değeri

N/A

Scopus Q Değeri

Q3

Cilt

Sayı

Künye