快速黏度分析仪表征籼米陈化过程中蛋白质与淀粉相互作用的研究

Study on interaction of protein and starch of indica rice during ageing by rapid visco analyzer

以新收获籼米为原料,在温度37℃、相对湿度85%条件下储藏20周,采用快速黏度分析仪研究,以不同浓度氯化钠、十二烷基硫酸钠(SDS)、β–巯基乙醇和抗坏血酸为测试溶剂对储藏过程中籼米峰值黏度和回生值的影响。结果发现,随着储藏时间的增加,籼米峰值黏度先上升后下降,回生值则持续上升;随着四种测试溶剂浓度的增加,峰值黏度增加,其中以β–巯基乙醇和SDS为测试溶剂峰值黏度增加最为显著;回生值随氯化钠、β–巯基乙醇和抗坏血酸浓度的增加而下降,随SDS浓度的增加而增加,其中以β–巯基乙醇为测试溶剂回生值下降最为显著。表明陈化导致大米蛋白形成二硫键以及疏水相互作用,通过抑制大米淀粉颗粒的糊化性质从而降低稻米的蒸煮食用品质。

Used new harvest indica rice as raw material, it was stored for 20 weeks under artificial accelerated ageing condition which was temperature of 37 ℃, relative humidity of 85%. Effects of different concentration of sodium chloride, sodium dodecyl sulfate, fl-mercaptoethanol, and ascorbic acid which used as test solution on peak viscosity and setback by rapid visco analyser were studied. The results indicated that as storage time increased, peak viscosity firstly increased, and then decreased; value of setback gradually increased. As concentration of the four kinds of test solution increased, peak viscosity increased, and the increase extent was the most significant when β-mercaptoethanol and sodium dodecyl sulfate were used. As concentration of sodium chloride, β-mercaptoethanol, and ascorbic acid increased, setback gradually increased, but setback decreased when concentration of sodium dodecyl sulfate increased. The results implied that rice ageing led to formation of disulfides and hydrophobic interactions of rice protein, which decreased pasting properties of rice starch, resulting in decrease of cooking and eating quality of rice.