摘要
研究发芽对糙米(品种:武运粳46)淀粉组分及含量、流变、凝胶、热力学和加工特性的影响。提取发芽0、24、48、72、96、120 h的糙米中的淀粉,用流变仪测定淀粉的动态流变学特性,质构仪测定淀粉凝胶的质构特性,并分析发芽对淀粉差示扫描量热(differential scanning calor imetry,DSC)图谱和加工性质的变化。结果表明:发芽后糙米中淀粉和直链淀粉含量均呈下降趋势;随发芽时间的延长,糙米中的淀粉在升温过程中弹性模量(G’)和黏性模量(G")的峰值增加,淀粉糊化变性时的温度下降,糙米淀粉的弹性和黏性得到改善;发芽对淀粉凝胶质构特性有不同程度的影响,其中凝胶强度、凝胶硬度、弹性、胶黏性、咀嚼性均在72 h达到最大值;DSC扫描图谱表明发芽使糊化焓增加,提高了其稳定性和结晶度,对淀粉的相转变温度(To、Tp、Tc)无显著影响(P>0.05);发芽改善了淀粉的乳化性和乳化稳定性;发芽后淀粉的持水性没有显著(P>0.05)变化,持油性整体呈上升趋势。发芽在一定程度上改变了糙米淀粉的功能性质。
The present work was designed to obtain information on the effect of germination on starch composition and rheological,gel,thermodynamic and processing properties of brown rice starch.Brown rice starch was extracted at different stages(0,24,48,72,96,and 120 h) of germination.The starch rheological properties were examined by a rheometer,the texture properties of starch gels were analyzed by texture analyzer and changes in thermodynamics and processing properties of starch during 120 h germination were also investigated.The results showed that the contents of total starch and amylase decreased over the germination period.With the extension of germination time,the peak values of G' and G' increased,denaturation temperature dropped and elasticity and viscosity went up.Germination had different impacts on the texture properties of starch gels.Gel strength,hardness,springiness,gumminess and chewiness reached a maximum level at 72 h.Differential scanning calorimetry(DSC) analysis showed that germination had little effect(P > 0.05) on phase transition temperatures(To,Tp,Tc) of starch,but the gelatinization enthalpy increased and the stability and crystallinity were improved.Moreover,the emulsifi cation and emulsion stability were also enhanced.Little effect of germination on its water-binding capacity was found(P > 0.05);in contrast,oil-holding capacity was improved.Therefore,germination can improve the functional properties of brown rice starch to some extents.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2015年第5期45-49,共5页
Food Science
基金
粮食公益性行业科研专项(201313011)
关键词
发芽
糙米淀粉
流变学特性
质构性质
热力学性质
germination
brown rice starch
rheological properties
texture properties
thermodynamic properties
