| 摘要註: |
文旦(Citrus maxima merr.)種子外層富含酸性多醣的黏質物。本論文以三種不同溫度條件 (80°C, 25°C與4°C)獲得的水萃物分別命名為high temperature water extract (HTWE)、room temperature water extract (RTWE)與low temperature water extract (LTWE)。三種水萃物在1% (w/v)的黏度分別為3025 cP、2575 cP與1650 cP。雖然HTWE具有較高的蛋白質含量(1.2%)與總酚含量(1.7%)，LTWE具有較高的醣醛酸含量 (57.6%)，但是三種水萃物在產率 (3.5-2.5%) 及總醣含量 (34.8-31.0%)並未呈現顯著差異。三種水萃物在陽離子以K+含量最多，約1.7-2.1%，其次為Ca2+、Na+、Mg2+與NH4+。將RTWE經陰離子交換層析 (DE-52 cellulose)呈現兩個主要fractions，分別存在於二次水流洗出的RTWE-Fraction A (RTWE-FA)以及於0.13-0.19 M NaCl濃度梯度流洗出的RTWE-Fraction B (RTWE-FB)。RTWE-FA的分子量小於3.5 kDa，且主要醣組成為glucose、fructose與sucrose，其相對比例依序為1.0：1.7：3.3；而RTWE-FB的分子量為176-589 kDa，總醣與醣醛酸含量分別為26.9%與65.4%，主要成分為galacturonic acid及一些微量成分，包括fucose、rhamnose、arabinose、galactose、glucose、mannose、glycerol、mannitol與gulonic acid γ-lactone或galactonic acid γ-lactone。以methylation及GC-MS linkage 分析結果顯示，RTWE-FB的主要鍵結為1,4-galacturonan。FTIR光譜顯示柚籽黏質粗萃及RTWE-FB與市售柑橘果膠 (Sigma, P9135)相似，且酯化程度大於60%。因此，推測文旦柚籽黏質是具有高酯化的homogalacturonan型式果膠。 The outer layer of shaddock (Citrus maxima merr.) seeds contains a large amount of mucilage-acidic polysaccharide. The polysaccharide was extracted using deionized water at three temperature conditions (80 °C, 25 °C and 4 °C). The extracts were designated as high-temperature water extract (HTWE), room-temperature water extract (RTWE), and low-temperature water extract (LTWE), and the viscosities of the extracts were 3025 cP, 2575 cP, and 1650 cP at 1% (w/v), respectively. Although HTWE contained the highest protein content (1.2%) and total phenol content (1.7%) of the three water extracts, LTWE contained the highest uronic acid content (57.6%). In addition, the three water extracts did not demonstrate a substantially dissimilar yield (3.5%-2.5%) or total sugar content (34.8%-31.0%). Potassium levels were the highest (approximately 1.7%-2.1%) among all of the cations in the three water extracts, followed by Ca2+, Na+, Mg2+, and NH4+. RTWE was separated into two major fractions by using anion-exchange chromatography on DE-52 cellulose. These major fractions were a neutral RTWE-Fraction A (RTWE-FA) and an acidic RTWE-Fraction B (RTWE-FB), which were collected during elution with water and 0.13-0.19 M of a NaCl gradient, respectively. RTWE-FA was less than 3.5 kDa in molecular weight, and the major sugar components were glucose, fructose, and sucrose, of which the respective ratios were 1.0：1.7：3.3. The range of the molecular weight of RTWE-FB was 176-589 kDa, and the total sugar and uronic acid contents were 26.9% and 65.4%, respectively. It mainly consisted of galacturonic acid with trace amounts of components, including fucose, rhamnose, arabinose, galactose, glucose, mannose, glycerol, mannitol, and gulonic acid γ-lactone or galactonic acid γ-lactone. Methylation and GC-MS analysis indicated that RTWE-FB was mainly composed of 1, 4-galacturonan. The FTIR spectra of the crude extract, RTWE-FB, and commercial pectin from citrus (Sigma, P9135) were extremely similar, and all exhibited a degree of esterification greater than 60%. Therefore, the mucilage of shaddock seeds is possibly a homogalacturonan-type pectin with high esterification. |