用谷朊粉溶涨指数法测定谷朊粉品质

Evaluate vital gluten quality with swelling index of vital gluten method

开发了一种新的谷朊粉品质检测方法。对小麦谷蛋白溶涨指数法的参数进行调整,在9种不同离心力条件下,测定从16个小麦品种中分离出的谷朊粉的溶涨指数,根据谷朊粉溶涨指数、面筋吸水率及面粉的蛋白质组分含量之间的关系,提出了用谷朊粉溶涨指数法测定谷朊粉品质的步骤及评价标准。结果认为:加入0.9mL蒸馏水水化10min,再加入0.9mL0.3%十二烷基磺酸钠(SDS)-乳酸溶液混合30min,最后用5000×g离心力进行离心是谷朊粉品质测定的最佳技术参数,在此条件下的谷朊粉溶涨指数与面筋吸水率、小麦谷蛋白溶涨指数呈显著正相关(r=0.541,0.547;P<0.05),与面筋指数、不溶性谷蛋白含量呈极显著正相关(r=0.608,0.589;P<0.01),与单体蛋白含量呈显著负相关(r=-0.573;P<0.05)。与测定谷朊粉品质的国家标准方法吸水率法相比,谷朊粉溶涨指数法能快速、稳定地反应小麦谷朊粉品质差异。

A new improved vital gluten quality testing method was developed. By using wheat swelling index of glutenin method to measure the quality of vital glutenin extracted from 16 wheat varieties, this paper focused on the swelling characteristics of vital glutenin by measuring it under 9 different centrifuge forces, gluten water absorption, wheat flour protein fraction content and their relationship. The results showed that using 0.9 mL distilled water to hydrate the vital glutenin for 10 min, then adding another 0.9 mL 0.3% SDS-Lactic acid solution and vortexing for another 30 min, centrifuging the mixture at 5000×g force was the best method for vital glutenin evaluation. The value of the vital gluten swelling index at 5000×g is positively significantly correlated with gluten water absorption, swelling index of glutenin, gluten index and insoluble glutenin (r=0.541, 0.547, 0.608, 0.589, respectively; P<(0.05)), and negatively correlated with monomeric protein (r=-0.573; P<0.05). Compared with the vital gluten national standard testing method, the swelling index of vital gluten can reflect the gluten content difference rapidly and reliably.