Effect Of Raw Materials Difference On Physicochemical Properties Of Brown Rice Flour And Quality Of Brown Rice Products

Although brown rice is rich in nutritional substance,its taste is rough and not suitable for eating.In order to improve the eating quality of rice products,floury treatment is considered as an effective method.The characters of crude materials can be regarded as one of the main factors of brown rice product.In present study,the physicochemical and properties of five different crude materials were evaluated,thus providing the theoretical basis for brown rice products selection in productive process.The main contents are as follows:The pasting properties of five different kinds of brown rice flour were evaluated,which includes hydration characteristics,pasting viscosity properties and thermal characteristics.The result means that,the amylose content of samples were in the range of17% to 22%,as the crude protein content was of 8.7%～11.2%.In addition,there was no significant different between total starh and crude fat concentration.On the other hand,the concnetration of amylose exhibited negative effect to the moisture of brown rice flour,as the moisture would significantly increased nearly 5 to 10 times at 100℃.The initial gelatinization temperature of brown rice flour was 61.55℃～73.85℃,with the increasing of amylose concentration,brown rice flour needed more energy for pasting.The result means that,the different sources of brown rice flour caused a significantly difference of water absorption,attenuation,initial gelatinization temperature,etc.In order to analyze the difference of five kinds of brown rice flour,gel properties,rheological properties,thermo-mechanical properties,in vitro starch digestion properties were regarded as the indicators.There was a significant difference of gel hardness and resilience between the samples.A significant change of Viscoelastic occurred from 60℃to 70℃,where the maximum elastic modulus size has a close relationship with amylose concentration.The quick digestible starch concentration of sample was 10.36%～19.48%,which were decreased with the increase of amylose concentration.The silty property of different rice varieties such as gel properties difference is bigger.In order to investigate the effect of different raw material on the quality of brown rice bread,brown rice bread was prepared with 20% gluten flour,where the specific volume,texture and starch digestion in vitro properties were considered as the indicators.The specific volume of different varieties of brown bread was greater than 2.5,when the amylose concentration was greater than 19%,the sticky,cohesive and starch digestibility of brown bread were significantly reduced and the hardness was significantly increased.Considering the quality of different varieties of brown rice bread,the variety of Hunan early brown rice was more suitable for the production of brown bread.In present study,semi-dry milling was used to prepare brown rice noodles,as cooking properties,texture properties,senses properties and in vitro digestibility of starch of brown rice noodles were regarded as the index,who analysis the effect of raw material on the quality of brown rice noodles.The optimist cooking time of five noodle samples were all above 10 minutes,whose cooking loss were more than 20%,when the amylose concentration was more than 19%,a flexible rice noodles could obtained.There was a significant differences of hardness,chewiness and other textural quality in the samples,and the evaluation score of wet brown rice noodles sensory were between 71.6～79.5.Hunan early brown rice noodles obtained the highest organoleptically acceptable and the lowest starch digestibility.Considering the quality of different varieties of brown rice noodles,the variety of Hunan early brown rice was more suitable for the production of brown rice noodles.According to the experimental results obtained,the amylose concentration in Hunan early brown rice were moderated,who was more appropriate for the production of brown rice bread and brown rice noodles,which could be the basis for selected raw materias when making brown rice bread and brown rice noodles.