HPLC-ELSD法测定梨果实中不同种类可溶性糖含量

采用高效液相色谱(HPLC)法测定4个品种梨果实中可溶性糖组分(葡萄糖、果糖、蔗糖、山梨糖醇)和含量。结果表明:高效液相色谱条件为CAPCELL PAK NH2(4.6 mm×250 mm,5μm)色谱柱,50℃柱温,流动相为乙腈-水(体积比为70∶30)溶液,流速为1.0 mL.min-1;蒸发光散射检测器(ELSD),漂移管温度为80℃,N2(氮气)流速为2.0 mL.min-1。在12 min内能准确检测出梨果实中4种糖,加标回收率为96.40%～103.20%。‘巴梨’、‘黄冠梨’、‘丰水梨’和‘砀山酥梨’果实中各种糖组分的HPLC-ELSD法测定结果表明,梨果实内主要的可溶性糖是葡萄糖、果糖、蔗糖和山梨糖醇,其中果糖含量最多,占总糖含量的43%～66%,其次为山梨糖醇和葡萄糖,分别占总糖含量的13%～28%和14%～18%,蔗糖含量最少,约占总糖含量的4%～12%。

Determination of contents and components of water-soluble sugar in pear fruit by HPLC-ELSD

The contents of water-soluble sugars(fructose,sucrose,glucose and sorbitol)in different pear cultivars were investigated by HPLC.The working condition of HPLC was CAPCELL PAK NH2(4.6 mm×250 mm,5 μm)column,constant temperature of 50 ℃,and CH3CN and H2O with a volume ratio of 70∶30 as mobile phase.The sugar components could be precisely separated in 12 minutes at a flow rate of 1.0 mL·min-1 by an ELSD detector(the temperature of drift tube 80 ℃,nitrogen flow 2.0 mL·min-1).The recovery was 96.40%-103.20%.As shown in the results of 4 pear cultivars(’Barlett’,’Huangguan’,’Houshui’,’Dangshansuli’),glucose,fructose,sucrose and sorbitol were the major water-soluble sugar in fruit.And among all sugar fractions determined in pear fruit,fructose predominated firstly(43%-66% of total sugar),then came sorbitol and glucose(about 13%-28% and 14%-18% of total sugar,respectively),and sucrose were at the least level,which was 4%-12% of total sugar.