不同加工方法对葛根淀粉血糖指数的影响

本实验采用体外法测定葛根淀粉和玉米淀粉在不同加工条件下的抗消化淀粉含量、淀粉水解百分率、淀粉水解指数以及由此推算的血糖指数的变化。实验结果表明 :经热作用的淀粉 ,其可消化淀粉含量大幅上升 ,抗消化淀粉含量显著减少。三种热处理方式 ,即蒸煮、微波、加压 ,都导致淀粉的水解速率提高 ,差异不明显 ,但以微波作用为最 ;加工后淀粉的血糖指数都大于 10 0 ,属于高血糖指数食品。

松花皮蛋风味成份的分离与鉴定

本实验采用Likeos—Nickerson水蒸汽蒸馏溶剂同步萃取装置,首次从无铅松花皮蛋中提取挥发性风味成份。运用气相色谱质谱联用技术对其进行分离分析,并借助计算机检索、文献对照和图谱解析等手段共鉴定出59种化合物(包括吡嗪类、含硫化合物类,芳香烃类、羰基化合物、羧酸、醇、酯和其它化合物类)。其中只有19种化合物为禽蛋或蛋类制品原有风味物质。

Relationships between Microbial Growth Parameters and Shelf Life of MAP Sliced Onions

Microbial counts （total aerobic psychrotrophic count （TPC）, lactic acid bacteria （LAB）, coliforms, pseudomonads, yeasts） and sensory properties of sliced onions stored at different temperatures and air compositions were investigated. Microbial counts were fitted to the modified Gompertz equation and the growth parameters of microorganisms (the initial cell number （N0）, maximum cell number (Nmax), maximum specific growth rate (μmax), lag-phase （（λ）） were obtained as derived parameters. The relationships between growth parameters of microorganisms and the microbial or sensory shelf life were built. The results showed that microbial counts increased and sensory qualities decreased during storage. TPC was predominant bacteria associated with spoilage of sliced onions under tested temperatures and air conditions. High correlation coefficients （r） were found between the lag time （λ） of TPC, coliforms, pseudomonads, yeasts and the microbial or sensory shelf life. The correlations between microbial or sensory shelf life and μmax of five microorganisms were between -0.69 and -0.86. The initial microbial counts （N0） of five microorganisms strains only showed a little correlation, and the maximum microbial counts (Nmax) showed no obvious correlation with shelf life except for LAB and yeasts.

热处理对苦荞麦粉总抗氧化能力的影响

采用分光光度计法和抗氧化能量指数法对来自重庆市城口县的苦荞麦粉中总黄酮含量和抗氧化能力进行了分析。样品加热(100℃,20min,样品:水=1:2,w/v)前后,总黄酮含量为83.52mg芦丁当量/100g干重和67.38mg芦丁当量/100g干重,ORAC值为76.45μmol TE/g干重和63.93μmol TE╱g干重,损失分别达到19.32％、16.38％,呈显著差异(P<0.05)。但热处理前后的苦荞麦粉都表现出良好的抗氧化性。