Effects Of Different Processing Methods On Rice Dough And Bread Quality

As the number of patients with celiac disease increases,the market demand for gluten-free food is also increasing.Celiac disease is an autoimmune disease,the only treatment for celiac disease,that is,lifelong prohibition of taking gluten-containing food.Rice has the characteristics of wide source,high nutritional value and low sensitization,is a high quality raw material for making food.The selection of rice as raw material of gluten-free food has a positive effect on the development of rice industry and the improvement of the quality of gluten-free food products in China.The effects of different processing methods on rice dough and bread quality were investigated by adding polysaccharide colloid,egg white protein or pregelatinizing rice flour.Using rice flour as raw material,the rice flour was pre-gelatinized,utilize the principle of gel network structure formed by the action of polysaccharide colloid and water,the effects of the addition of polysaccharide colloid on dough properties and bread baking properties before and after pre-gelatinization were determined.The results showed that the quality of dough and bread was improved by adding konjac powder.Amorphophallus swell and release konjac glucomannan polymer in water,konjac glucomannan can be reconstituted to form a three dimensional network structure,improve dough retention.Pre-gelatinization can increase the viscosity of rice flour,to help the dough form a dense surface structure,so that the gas produced during fermentation is not easy to escape.When 1.5 % konjac powder was added to pre-gelatinized rice flour,volume of bread increased from 1.19 mL/g to 1.93 mL/g,bread product quality and sensory score were also significantly improved.The egg white protein was modified by microwave(physical method)and glutamine transaminase(biological method),increase the gelation,foaming and foam stability of egg white protein,the effects of egg white protein addition on dough properties and bread baking properties were determined.Egg white protein treated by TG enzyme,egg white protein foaming property and foam stability were significantly improved.Adding it to the bread gives the bread a better volume,texture and sensory quality.The overall score of bread is as high as 8.17,in which the flavor and taste score of bread is even comparable to that of wheat bread.When added 5.0 % to the egg white protein treated with glutamine transaminase,the dough and bread do the best,some smooth bubble films even appeared in the bread microstructure.Adding different concentrations of konjac powder,egg white protein and glutamine transaminase to rice flour,explore the best recipe for bread.Experimental results show that,the order of influence of three additives on dough and bread is egg white protein >konjac powder >glutamine transaminase.If the amount of egg white protein is 8.0 %,the amount of konjac powder is 1.5 %,and the amount of glutamine aminotransferase is 5.0 %,the waking volume of dough is 36.53 mL;bread has the largest specific capacity,about 2.31 mL/g;the hardness of bread decreased by nearly 88.59 %;the sensory score of bread was 8.21,comparable to that of wheat bread.