关键词：
半乳甘露低聚糖;活性炭;色素脱除率;糖回收率;吸附等温线
摘 要：
旨在通过活性炭对半乳甘露低聚糖溶液进行脱色精制,从而提高半乳甘露低聚糖的纯度。首先,运用单因素试验和正交试验方法,获得最佳的脱色条件,最后对脱色后的产物进行红外分析及吸附等温线的测定。研究发现:相比于粉末活性炭和柱状活性炭,颗粒活性炭的选择性脱色精制效果最佳,因此选择颗粒活性炭进行下一步的单因素试验和正交优化试验。首先通过单因素试验对条件进行初步筛选,随后对筛选的条件进行正交优化,获得颗粒活性炭脱色的最佳条件为添加量8%、吸附温度45℃、吸附时间70 min,此时酚类色素和美拉德色素的脱除率分别为91.08%和66.52%,半乳甘露低聚糖回收率为93.53%。同时,经红外分析发现,活性炭在脱色的同时没有改变多糖的糖残基结构。此外,通过吸附等温线的分析,发现颗粒活性炭对色素的吸附等温线属于Ⅰ型,即Langmuir等温线,且颗粒活性炭对酚类色素和美拉德色素的饱和吸附容量分别为0.32和0.57 g/g。试验结果表明,颗粒活性炭可用于半乳甘露低聚糖溶液中色素的脱除,同时可最大限度地减少对半乳甘露低聚糖的吸收。
译 名：
Investigation of decolorization of galactomanno- oligosaccharides by activated carbon
作 者：
HUANG Caoxing;TAO Yuheng;LIAO Jili;WANG Xinyan;YONG Qiang;College of Chemical Engineering, Nanjing Forestry University;
关键词：
galactomanno-oligosaccharides;;active carbon;;decolorization rate;;sugar recovery rate;;adsorption isotherm
摘 要：
In recent years, galactomanno-oligosaccharides(GMOS) have received more and more attention due to their excellent immune-enhancing effects and the function of regulating intestinal flora. Therefore, more researchers are devoted to the preparation of GMOS, however the obtained crude GMOS usually contain impurities such as proteins and pigments. In order to expand the application of GMOS to the fields of food and medicine, the decolorization and purification of GMOS is necessary. Herein, it is expected to decolorize and refine the GMOS solution by activated carbon, thereby improving the purity of the GMOS. Firstly, the single factor test, including activated carbon type, addition amount, adsorption temperature and adsorption time, was carried out, followed by the orthogonal test, to obtain the best decolorization conditions. Moreover, The infrared analysis and adsorption isotherm determination analysis were used to characterize the decolorized product. In the selection of activated carbon type, compared with the powdered activated carbon and columnar activated carbon, the granular activated carbon had the best selective decolorization effect. Therefore, the granular activated carbon was selected for the next single factor and orthogonal optimization experiment. Firstly, the conditions were preliminarily screened through single-factor experiments, and then the selected conditions were orthogonally optimized. Consequently, the best conditions of the addition amount, adsorption temperature and adsorption time were 8%, 45 ℃, and 70 min, respectively. At this time, the removal rates of phenolic pigments and Maillard pigments were 91.08% and 66.52%, respectively, followed by the recovery rate of GMOS of 93.53%. Then, through the infrared analysis, it was found that the activated carbon did not change the structure of polysaccharide sugar residues while decolorizing. In addition, the analysis of adsorption isotherms indicated that the adsorption of granular activated carbon for pigments belongs to type I isotherm, namely Langmuir isotherm. More importantly, the saturated adsorption capacities of granular activated carbon for phenolic pigments and Maillard pigments were 0.32 and 0.57 g/g, respectively. Overall, the experimental results show that the granular activated carbon can be used to remove the pigment in the GMOS solution, as well as minimizing the loss of GMOS. This research lays the foundation for the application of GMOS in the food field.
