Antioxidant and Antimicrobial Effects of Extracts from Hydrolysates of Lignocellulosic Materials

Abstract

The antioxidant and antimicrobial activities of ethyl acetate extracts obtained from acid hydrolysates of several lignocellulosic materials (Eucalyptus globulus wood, barley bran, corn cobs, and corn leaves) were evaluated. The minimum inhibitory and bactericide concentrations (MIC and MBC, respectively) were determined against a selection of bacteria and yeasts. Extracts from Eucalyptus wood hydrolysates were the most active for inhibiting bacteria and yeast growth, with MIC in the range of 10(2)--5 x 10(3) microg/mL and MBC in the range of 10(3)--0(5) microg/mL. Bacteriogenic and bacteriostatic activities of extracts from Eucalyptus wood and barley bran acid hydrolysates were slightly higher than those of corn cobs and leaves. Both the radical scavenging capacity and the inhibition of the beta-carotene bleaching caused by extracts were determined and compared with those of synthetic antioxidants. The antioxidant activity of extracts increased with their concentrations in the media, the stronger properties corresponding to those obtained from Eucalyptus wood hydrolysates.

Reductive de-polymerization of kraft lignin for chemicals and fuels using formic acid as an in-situ hydrogen source

“…Lignins produced from kraft process or soda process are mainly burned as low value fuel for energy generation, while kraft pulping process is the predominating process in pulp and paper industry. Thus, intensive research has been being carried out to investigate valorization of kraft lignin for various high-value chemicals such as antioxidants, antimicrobial, antifugal agents (Cruz et al, 2001), flameretardants (Reti et al, 2008), or anti-sunlight/frost coating (Miidla, 1980) and UVabsorbent films (Liu et al, 2014).…”

Phenolic content, antioxidant activity and antiamylolytic activity of extracts obtained from bioprocessed pineapple and guava wastes

“…When it comes to the effect of thermal concentration of the bioprocessed samples, a slight antioxidant decrease was observed for both concentrated fruit extracts. This could be caused by partial thermal-induced degradation of highly polymerized phenolics, known to be potent antioxidants (Cruz et al, 2001), which would lead to a little decrease of the antioxidant capacity of the concentrated extracts and the formation of simple detectable phenolics, which would also contribute to the extra TPC increase observed (Randhir et al, 2008).…”

Significance of Ethanol Product of Gmelina arborea

“…The neutralized solution was poured on the open flat surface of Buchner funnel whose protruding end was placed in a conical lask [19][20][21][22][23][24][25]. By so doing, the lignin component of the solution in form of black solid residue remained in the funnel, from where it was disposed while liquid filtrate of fermentable sugar solution was collected in the conical flask.…”