不同大麦品种来源β-葡聚糖流变学特性

Rheological behavior of β-glucan extracted from different varieties of barley

优化大麦β-葡聚糖提取工艺,在提取料水比1∶10,提取液pH=7,提取温度60℃,提取时间4h条件下,可得纯度为96.89%、分子量为1×106大麦β-葡聚糖;利用凝胶过滤色谱法测定5种不同大麦品种来源β-葡聚糖分子特征参数,并使用静态和动态粘弹性测定法研究其流变学特性。结果表明,所得大麦β-葡聚糖分子量在不同大麦品种间差异较大,在0.6×106～1.8×106之间;在浓度0.8%及以上时,江苏啤麦β-葡聚糖具有明显假塑性流体特征;与其它品种相比,1.0%浓度江苏饲麦β-葡聚糖溶液零剪切粘度最低,说明β-葡聚糖分子量越高,分布范围越窄,零剪切粘度越高;浓度为2.0%江苏啤麦具有显著弹性特征,在5个品种中表现出最高增稠能力。

The extraction process of barley β-glucan was optimized. The purity of β-glucan was up to highest one of 96.89% with the optimized extraction condition, i.e. flour/water ratio 1 ： 10, extracting temperature 50 ℃, pH 7.0, extracting duration 4 h; and the molecular weight of the product was 1 × 10^6. Molecular characterization of barley β-glucan extracted from 5 different varieties was investigated by high-performance size exclusion chromatography. The rheological properties of these β-glucans in the aqueous solution were studied both by static and dynamic viscoelastic measurement. The molecular weight of barley β-glucan extracted from different varieties was significant different and the molecular weight range of samples is between 0.6× 10^6 and 1.8 × 10^6. Barley ＂Jiangsusimai＂ β-glucan solution had a typical pseudo-plastic fluid characteristic at the concentration of 0.8% or above. Compared with other varieties, barley ＂Jiangsusimai＂ β-glucan solution had the lowest viscosity at the concentration of 1.0%. The low shear rate viscosity was higher with the higher molecular weight and the narrower molecular weight distribution. Barley ＂Jiangsusimai＂ β-glucan solution which has significant elastic characteristic at the concentration of 2.0% showed the most efficient thickening ability in the five varieties.