Relationship Between Quality Properties Of Soft Gluten Wheat And Biscuit Quality

In this study, the physical quality, milling quality, protein quality, rheological property, starch quality and solvent retention capacity (Solvent retention capacity, SRC) of 11 soft gluten wheat varieties (strains) Were analysed systematically. In according to the industry standard of biscuit flour in the People's Republic of China (SB / T 10141-93), biscuits were made and the water absorption, diameter, height, hardness, brittleness and toughness of these biscuits were analysed and evaluated. The relation between the quality of soft gluten wheat varieties and the quality characteristics of biscuits was researched. And biscuits made of medium gluten flour which added different types and proportion of starch to improve the quality parameters of biscuit flour were also studied. The results of experiment indicated:(1) The wet gluten content of Zhengmai 2411, Yumai 50, Yangmai 13, Zhengmai 004, Taikong 5 and Pubing 143 is more than 26%, they can not reach the requirements of ordinary level of biscuits flour. Ningmai 13 meets the requirements of ordinary level of biscuits flour, and Yangmai 15, Yangmai 9, Ningmai 9 and Mianyang 30 have reached the requirements of refine level of biscuits flour.(2) The negative correlation between biscuit diameter and extension energy was very significant, the diameter and valoremeter value was significant, the water absorption of biscuit and the weight of 1000 kernels was also significant. There was very significant negative correlation between the brittleness of biscuit and the weight of 1000 kernels, but the brittleness of biscuit and the ash content was significant positive correlation. The negative correlation btween the water absorption of biscuit and amylose content was very significant, and the water absorption of biscuit and amylopectin content was significant positive. So in the process of making biscuit, the weight of 1000 kernels, the ash content, valoremeter value, extension energy, the content of amylase and amylopectin and so on can predict the quality of biscuits.(3) The diameter of biscuits and the SRC of distilled water, the SRC of 50% sucrose solution, the SRC of 5% sodium bicarbonate solution, the SRC of 5% lactic acid solution all were significant negative correlation or very significant negative correlation. The SRC of 50% sucrose solution and the water absorption of biscuits was very significant positive correlation.(4) The biscuit quality order of testing wheat varieties matched very well according to the indexes of biscuit quality standards and results of SRC. In the two orders, the quality of biscuits made of Ningmai 9, Yangmai 9, Mianyang 30 and Yumai 50 were better, the quality of biscuits made of Zhengmai 2441, Ningmai 13 and Pubing143 were not so good. It showed that the method of SCR was sciential and accurate, so it was totally feasible to select SRC as a quality index of biscuit flour.(5) With the increase of the amount of starch addition, the content of protein and wet gluten, granularity and the water absorption were all decreased, and there is no significant changes in sedimentation value. After added starch to the flour, the Y value of mixed flour was increased, but the x and y value were decreased. For the same proportion but different kinds of starch, the whiteness of the flour blended with corn starch was the best; the maximum viscosity and breakdown of the flour blended with potato starch were higher, but the setback was the lowest; the setback of the flour mixed with wheat starch was the highest. The increase of starch enhanced the bulge rate of biscuit, reduced the hardness and the toughness, and improved the brittleness. The quality of the biscuit which used the blended flour with 20% wheat starch was the closest to Ningmai 9 and was the most suitable for biscuit producing.