Evaluate vital gluten quality with swelling index of vital gluten method

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.