苹果果胶的结构、单糖组分和稳定性研究

对苹果果胶的结构、单糖组分及稳定性进行研究.采用傅立叶变换红外光谱仪测定苹果果胶的结构,毛细管气相色谱法测定果胶多糖的单糖组分,粘度法测定果胶在不同浓度的糖、盐、过氧化物存在时粘度的变化.结果表明:苹果果胶中舍有部分甲氧基和少量乙酰基,具有一般果胶结构,果胶多糖中含有8种单糖.葡萄糖和麦芽糖对苹果果胶还原粘度起促进作用,而糊精相反.盐能降低果胶粘度,低浓度的盐作用最显著,过硫酸铵由于改变了果胶液的离子强度和pH,因而能增大果胶粘度.

Study on the structure, monosaccharide composition and stability of apple pectin

The structure, monosaccharide composition and stability of apple pectin were investigated.FT-IR and HPGC were developed to determine structure and monosaccharide composition of apple pectin.The stability of apple pectin in the presence of different sugars, salts and peroxides was also determined. Results showed that eight monosaccharides,some methoxyl and acetyl were included in the apple pectin molecule.Glucose and maltose were found to increase the reduced viscosity of pectin solutions whereas dextrin decreased it.The viscosity of the pectin solutions decreased in the presence of salts.When the salt concentration increased ,great decreases were observed in the low salt concentrations. When the concentrations of the pectin solutions were increased in the presence of ammonium persulfate,the increase in the ratio of reduced viscosity to initial reduced viscosity was higher.