燕麦抗冻蛋白对面筋蛋白冻融稳定性的影响

将燕麦抗冻蛋白(AsAFPs)加入到小麦面筋蛋白中,通过测定冻融循环条件下的小麦面筋蛋白的持水性、持油性、乳化和乳化稳定性、二级结构和弛豫时间,研究AsAFPs对冻融小麦面筋蛋白品质的影响。结果表明:经过5次冻融循环后,小麦面筋蛋白的持水率由92.8%降到87.8%,而AsAFPs的加入能够减缓冻融循环过程中水分的流失,使小麦面筋蛋白的持水率由92.8%降到89.8%;小麦面筋蛋白持油性呈上升趋势,AsAFPs的加入可以减少疏水键的暴露,使小麦面筋蛋白持油性低于对照组;小麦面筋蛋白的乳化性降低,乳化稳定性升高,加入AsAFPs后,其乳化性升高,乳化稳定性降低;小麦面筋蛋白无规则卷曲、α-螺旋整体呈下降趋势,而β-折叠和β-转角整体呈上升趋势,加入AsAFPs后无规则卷曲、α-螺旋下降的幅度变小;小麦面筋蛋白的冻结水逐渐向自由水转变,AsAFPs组小麦面筋蛋白结合水和自由水的含量变化幅度均小于对照组。

Freeze-thawad stability of hydrated gluten as influenced by antifreeze protein from oat (Avena sativa L.)

Oat antifreeze protein(AsAFPs) was added to hydrated gluten. The effect of oat antifreeze protein on the quality of freeze-thawed gluten was studied by measuring the water retention, oil holding, emulsifying and emulsifying stability, the secondary structure and relaxation time of wheat gluten. The results showed that after five freeze-thaw cycles, the moisture holding rate of hydrated gluten decreased from 92.8% to 87.8%, while with addition of AsAFPs, the moisture holding rate decreased from 92.8% to 89.8%. This may be because the addition of AsAFPs could slow down the water loss in the freezing-thawing cycle. The oil retention of gluten protein is on the rise. The addition of AsAFPs could reduce the exposure of hydrophobic bonds, making the oil retention of gluten protein lower than that of the control group. The emulsification of gluten was decreased and the emulsion stability was increased. After the addition of AsAFPs, the emulsifiability was increased and the emulsification stability was decreased, this may be because the addition of AsAFPs could inhibit the denaturation of gluten. The alpha-helix of wheat hydrated gluten was decreased as a whole, while the overall trend of beta-folding and beta-corner was increased. The amplitude of irregular curl alpha helix of wheat gluten protein decreased after AsAFPs was added. The frozen water of wheat hydrated gluten gradually changed to free water, while the content of bound water and free water in the AsAFPs group changed less than those in the control group.