The Study Of The Influence Of Wheat Flour Pasting Properties On The Quality Of Steamed Bread

This experiment selected representative wheats from four different regions (two of them are suitable for making northern steamed bread, other two of them are suitable for making the southern steamed bread) for germination. After being milled, the germinating wheat flour was added into the original wheat flour at different levels. Six kinds of relatively high quality commercial production basic flour are selected, three of them are medium gluten wheat flour which is suitable for making northern steamed bread and other three of them are low gluten wheat flour which is suitable for making the southern steamed bread. Bacterial a-amylase is added into these commercial production basic flours at different levels, then the physicochemical, rheological and viscometric indexes are detected and the quality of steamed bread is evaluated. According to the correlation between indexes and the quality of steamed bread, the fitting scopes of falling value and gelatinization characteristic parameters which are vital indexes for making steamed bread are obtained.The result shows that with the proportion of germinated wheat or bacteria a-amylase increasing, falling values of four experimental grinding wheat flours and six commercial steamed bread basic flours fall clearly, indexes of the flour quality and farinograph quality number decline, except extensograph extensibility which increases. Bubble meter of P values, W and P/L value decline as the adding mount increasing, on the opposite, the L value rises. Indexes of RVA viscosity meter and Brabender viscometer change significantly. Except the gelatinization temperature (initial gelatinization temperature) which increases, rest indexes decline sharply, adding germinated wheat flour the pasting viscosity and peak time and falling number has a significant positive correlation. When the adding amount at a low level, the specific volume and the score of some steam breads have a slight upward trend. On the other hand, when the adding amount at a high level generally the quality of steamed bread made of wheat flour has a downward trend clearly. The steamed bread quality and TPA indicators falls, except the viscosity value which is on the rise. Analysis shows that the falling number and pasting viscosity of wheat flour has a significant positive correlation with the quality of steam bread.Through choosing steamed bread which own better quality, the falling number and gelatinization property index of wheat flours were analyzed. The suitable falling number and gelatinization property indexes for steamed bread making as follows, north steamed bread: falling number>300s, RVA Peak viscosity>850cp, Brabender Peak viscosity>220BU. The southern steamed bread:falling number>240s, RVA Peak Visco>600cp, Brabender Peak Visco>220BU.