常压空气冷等离子处理对陈小麦生理生化及面团糊化特性的影响

Effect of Atmospheric Pressure Cold Plasma on the Physiological Biochemistry of Stale Wheat and Its Dough Pasting Properties

采用30 W的常压空气冷等离子(APCP)处理陈小麦,处理时间分别是0、14、18、22及26 min,分析了小麦生理生化及面团糊化特性指标的变化。结果表明,14~26 min冷等离子处理显著(P<0.05)降低小麦籽粒水滴接触角、发芽率及陈化指数,而籽粒破碎率和吸水率显著(P<0.05)增加。可溶蛋白及巯基的含量随等离子处理时间趋向于增加。深入分析面团糊化特性,与0 min处理比较,等离子处理时间加长,面团醒发时间趋于增加,稳定时间趋于减少;最大稠度、混合结束时扭矩、最小扭矩、最终扭矩均趋于减少,而糊化峰值扭矩和加热结束时扭矩趋于不变;C1峰值幅度明显减少,蛋白质网络弱化趋于减少,淀粉酶活性增大,淀粉回生程度趋于降低,对应蛋白网络弱化速率和糊化速率增大、蒸煮稳定速率趋于减少,破损淀粉则明显减少。APCP可能通过增大过氧化物酶和淀粉酶活性而提高陈小麦面团蛋白强度和面团稳定性。

The stale wheat was treated 0,14,18,22,and 26 min with 30 W atmospheric pressure cold plasma(APCP),respectively. After 14~26 min APCP treatment,the water drop contact angle of a wheat kernel significantly(P<0.05)reduced,and its germination rate and stale index significantly(P<0.05)decreased while its kernel broken percent and water-absorption rate were significantly increased. The contents of soluble protein and sulfuryl group increased with treatment time. Further analyzed the pasting properties of whole wheat flour showed,compared with the sample treated with 0 min,with the increasing in APCP treatment time,dough development time tended to increase while the dough stability time tended to decrease. The maximum consistency torque(C1),a torque at end of mixing(Cs),the minimum torque(C2),and final torque(C5)all tended to decrease,but the pasting peak torque(C3)and the torque(C4)at end of heating tended to unchanged. The amplitude of C1 torque peak significantly reduced. The weakness of protein network(C1-Cs)tended to decrease,the amylase activity(C3/C4)and the extent of starch retrogradation tended to decrease. These changes were related to a slight increase in heating rate(α)and pasting rate(β),with a decreasing tendency in enzymatic rate(γ). Cold plasma treatment significantly decreased damaged starch in the whole wheat flour. The study suggested that the atmospheric pressure cold plasma could modify the strength of protein network and the pasting properties of whole flour in stale wheat possibly by increasing peroxidase and amylase activities in a wheat kernel.