학술논문
Saccharification of Gelidium amansii by Acid Hydrolysis to Generate Mixed sugars : Parameter Effects and 3,6-AHG Determination
Document Type
Dissertation/ Thesis
Source
Subject
Language
Korean
Abstract
Various factors affecting galactose and glucose yields were investigated using 3 types of substrates, Gelidium amansii, fiber and agar in the presence of several acid catalysts in aqueous solution. There have been found that a variety of reaction conditions should be carefully considered to obtain maximum fermentable sugars such as galactose and glucose with a concomitant minimizing 5-HMF, known as fermentation inhibitor. Where using a Gelidium amansii as a substrate in the presence of H2SO4 aqueous solution, the maximum sugar yields(33.7%) were obtained in 1.0% of H2SO4 solution and in a temperature range of 140~150℃ for 15min of reaction time. When using a fiber which is previously extracted from Gelidium amansii, in the presence of H2SO4, the maximum glucose yield(61%) was obtained in 0.4% of sulfuric acid aqueous solution and in the temperature of 190℃ for 15min. To study a facile method for 3,6-AHG quantification, quantitative analysis resulted from acid-catalyzed hydrolyzate by PA1 column were carefully compared whit those from the reductive hydrolysis by MA1 column as a function of combined severity. This new approach provides a series of factors that is able to calculate the amount of 3,6-AHG produced during the acid-catalyzed hydrolysis of Gelidium amansii expeditiously. Due to the acid-labile character of 3,6-AHG which leads to a fermentation inhibitor, 5-HMF, a variety of acidic ionic liquids were investigated in terms of ability to regulate acidity, providing a milder condition than sulfuric acid. Indeed, in case of using agar as a substrate, various acidic ionic liquids such as [Bmim][HSO4], [Hmim][HSO4], [Choline][HSO4], [Bu4N][HSO4], [BU4P]HSO4, [Morpholium][HSO4] showed high yields of both galactose and 3,6-AHG with a remarkable decrease in 5-HMF formation. Among them, [Choline][HSO4] showed highest yields of sugars with a reasonable range of minimized 5-HMF formation.