【摘要】 利用蒸汽爆破技术对板栗苞刺进行不同爆破条件的预处理，通过色差仪、扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)和X射线衍射(XRD)分析蒸汽爆破前后苞刺外观颜色、微观状态和纤维化学结构变化;通过测定显色反应吸光度分析蒸汽爆破前后苞刺提取物中多酚和多糖含量的变化，筛选出蒸汽爆破最优条件，进一步研究蒸汽爆破前后苞刺提取物对DPPH和ABTS自由基的清除率，分析板栗苞刺提取物抗氧化活性与多酚含量间的相关性。研究结果表明:板栗苞刺的色差随着爆破程度的增强而增大，高强度的蒸汽爆破加速了棕色素的形成，且伴随着可溶性多糖和多酚含量的增加; SEM、FT-IR和XRD分析显示适当条件的蒸汽爆破对板栗苞刺微观结构产生破壁现象，纤维素结晶度增大，有利于板栗苞刺中多酚和多糖等成分的溶出。在2.0 MPa和5 min的条件下，多酚质量分数达到最高值为186.88 mg/g(以原料质量计)，在蒸汽爆破1.0 MPa/10 min+1.5 MPa/6 min的条件下，多糖质量分数达到最高值为140.13 mg/g。从绿色环保的角度出发，可选择2.0 MPa和5 min作为蒸汽爆破的最佳条件。采用70%乙醇提取蒸汽爆破(2.0 MPa和5 min)后板栗苞刺，当提取物质量浓度为0.1 g/L时，对DPPH、ABTS自由基的清除率达到最大，分别为64.47%、72.43%，对多酚含量与DPPH、ABTS自由基清除率进行线性拟合发现，2种自由基清除率与多酚含量有很好的相关性，相关系数分别为0.886 5和0.930 3。更多还原

【Abstract】 Pre-treatment of chestnut burs using steam explosion technology under different conditions was conducted.Changes in bur appearance color,microscopic state,and fiber structure before and after steam explosion were analyzed via color difference analysis,scanning electron microscopy(SEM),fourier transform infrared spectroscopy(FT-IR),and X-ray diffraction(XRD).Chromogenic reaction absorbance analysis was employed to assess changes in polyphenol and polysaccharide content in bur extract before and after steam bursting,identifying optimal bursting conditions.Subsequently,the radical scavenging rates of bur extracts against DPPH and ABTS radicals were investigated,and the correlation between antioxidant activity and polyphenol content in chestnut bur extracts was analyzed.The results indicated that chestnut burs exhibited increased color difference with heightened bursting intensity.High-intensity steam bursting accelerated brown pigment formation while concurrently increasing soluble polysaccharide and polyphenol content.SEM,FT-IR,and XRD analyses revealed that steam bursting under optimal conditions induced cell wall disruption in chestnut burs,increasing cellulose crystallinity and enhancing the solubilization of polyphenols and polysaccharides.Under 2.0 MPa for 5 min,the polyphenol mass fraction reached its maximum value of 186.88 mg/g(based on raw material weight).Under the steam bursting conditions of 1.0 MPa/10 min + 1.5 MPa/6 min,the polysaccharide mass fraction reached its maximum value of 140.13 mg/g.From the environmental perspective,2.0 MPa and 5 min was selected as the optimal steam bursting condition.Using 70% ethanol to extract steam-exploded chestnut burs(2.0 MPa and 5 min),the extract exhibited maximum radical scavenging rates against DPPH and ABTS radicals at mass concentrations of 0.1 g/L,reaching64.47% and 72.43%,respectively.Linear regression analysis of polyphenol content against DPPH and ABTS radical scavenging rates showed a strong correlation with polyphenol content,with the correlation coefficients of 0.886 5 and 0.930 3,respectively.更多还原