Effect Of Electron Beam Irradiation On The Ethanol Fermentation Characteristics Of Sorghum Flour And The Fermentation Quality Of Mixed Dough

Sorghum is often used as an essential raw material for liquor brewing and industrial production of alcohol owing to its high starch,low-fat content,and appropriate amount of protein and tannin.In addition,the minerals and various bioactive compounds contained in sorghum are very beneficial to human health,so it is also commonly used to produce coarse grain products such as steamed bread,bread,noodles,etc.Especially in the era of social development and the accelerated pace of people’s life,bread has become the staple food of many consumers.However,the traditional alcohol production process has high energy consumption and complex operation.Then the emerging raw material fermentation is prone to contamination by miscellaneous bacteria.In addition,sorghum has poor color and flavor and does not contain gluten protein,resulting in bread mixed with wheat flour with low fermentation height,poor texture,and easy age.Electron beam irradiation（EBI）is a pretreatment method that physically modifies starch-based materials.After EBI treatment,the ordered structure of starch molecules is destroyed,and the molecules are degraded to produce small molecules of sugar,dextrin,etc.This can promote the enzymatic hydrolysis and alcohol fermentation of starch,at the same time,is conducive to the growth and reproduction of yeast,thus improving the gas production capacity.So it is expected to solve the above-related problems.Therefore,the sorghum flour was treated by EBI at different doses（0,2,4,6,8,and10 k Gy）in this study to explore the effects of EBI on the alcohol fermentation of sorghum flour and the quality of sorghum-wheat mixed dough and bread.The best irradiation dose for dough and bread quality was selected.Furthermore,the optimum addition ratio of sorghum flour with this irradiation dose in the production of mixed bread was investigated.The main results were as follows:（1）After EBI treatment,the amylose content in sorghum flour decreased,while the reducing sugar content increased significantly.In addition,EBI seriously damaged the crystal structure of sorghum starch,which increased its solubility in water.These changes in physicochemical properties and structure have improved the efficiency of enzymatic saccharification and alcohol fermentation of sorghum flour.The enzymatic dextrose equivalent（DE）value,weight loss of CO₂during fermentation,ethanol concentration,and ethanol yield all exhibited a trend of initially increasing and then decreasing as the irradiation dose increased,reaching the maximum at 8 k Gy.（2）Sorghum flour treated with different doses of EBI was mixed with high-gluten wheat flour in a proportion of 30%.As the EBI dose increased,the fermentation expansion height,total gas release volume,gas retention coefficient of the mixed dough,and specific volume of mixed bread all showed a trend of increasing and then decreasing,reaching the maximum when the EBI dose was 4 k Gy.At this time,the expansion height of the dough was 55.2 mm,which was not significantly different from wheat flour dough（WF）.The texture analysis of fresh and stored at 4℃bread core showed that the hardness value and chewiness of sorghum flour mixed bread after 4 k Gy irradiation（ESF4）was significantly lower than that of non-irradiated（NSF）.The complete results indicated that ESF4 dough and bread quality is superior to NSF in many aspects,but there is still a particular gap compared to WF.（3）The sorghum flour treated with 4 k Gy EBI was mixed with high-gluten wheat flour in different proportions（10,20,30,40,and 50%）.With the addition proportion increased,the farinographic properties of the dough became worse;the expansion height and gas retention coefficient significantly decreased during fermentation.Under the same addition proportion,the fermentation-related parameters of EBI sorghum flour mixed dough（ESF）were considerably higher than those of non-irradiated（NSF）.When the addition ratio was 10%,compared with WF,the fermentation height and gas release volume of ESF dough did not significantly change,and the gas retention coefficient significantly increased;the hardness and chewiness of bread decreased,while the cohesiveness increased significantly,and the trend of changes in related parameters was slower under 4℃storage conditions.The complete results indicated that when sorghum flour treated with 4 k Gy irradiation is mixed with wheat flour in a 10%ratio,the quality of dough and bread is similar to or even better than WF in many aspects,and the aging characteristics of bread are significantly improved.