Effects Of Grain Protein And Components On Eating Quality Of Proso Millet

As one of China’s characteristic grain crops,proso millet has edible and medicinal value.With the improvement of people’s living standards,the demand for high-quality proso millet is increasing.As an important nutrient for proso millet,the content and compositions of protein affect the quality of proso mille.At present,research on proso millet mainly focuses on the effects of stress resistant cultivation techniques and starch characteristics on eating quality.Therefore,this study analyzed and comprehensively evaluated the appearance quality,nutritional quality and gelatinization characteristics of excellent proso millet germplasm resources,selection of high and low protein non-waxy and waxy proso millet varieties as experimental material analyzed the proso millet protein characteristics,on this basis,to explore the effect of protein content and compositions on powder structure,gel consistency and gelatinization properties,thermal properties of proso millet.The main research results are as follows:(1)The 301 germplasm resources of proso millet showed rich genetic variation.Correlation analysis showed that amylose content was positively correlated with red-green value,1000-grain weight,grain viscosity,final viscosity,recovery value,gelatinization time and gelatinization temperature,and negatively correlated with brightness value,yellow-blue value,peak viscosity and damage value.Protein content was positively correlated with red and green values,and negatively correlated with peak viscosity,valley viscosity,damage value and final viscosity.Fat content was negatively correlated with red and green values,yellow and blue values,thousand grain weight,grain viscosity,final viscosity,recovery value,gelatinization time and gelatinization temperature.The principal components of 17 quality characters were analyzed and 4 principal components were extracted.The cumulative contribution rate of these four principal components was 79.00%,which was mainly related to starch and fat content,gelatinization viscosity,recovery value,gelatinization time and gelatinization temperature.(2)Compared with protein of rice,buckwheat,foxtail millet and sorghum,the protein particles of proso millet were significantly smaller than those of other crops.The essential amino acid composition of proso millet is better than that of the other crops,and the essential amino acid content of proso millet with high protein content is higher than that of proso millet with low protein content.The protein solubility of non-waxy proso millet varieties is significantly higher than that of waxy proso millet varieties,and the solubility of those with low protein content is significantly higher than that of those with high protein content.Proso millet varieties with higher protein content of protein has higher water and oil holding capacity,emulsifying capacity than that of low protein content of proso millet varieties.The influence of protein content on emulsifying stability of waxy and non-waxy proso millet is different.(3)Compared with the low amylose varieties,the proso millet with high amylose had higher paste viscosity,gelatinization time,gelatinization temperature,water absorption,volume expansion rate and hardness,but lower gelatinization enthalpy.The higher the protein content is,the greater the viscosity of the whole powder paste,the smaller the water absorption rate and volume expansion rate of proso millet rice,and the greater the gelatinization temperature and hardness of proso millet rice.Proso millet with high amylose and protein content has poor cooking ability,high energy consumption and long cooking time.Therefore,appropriate reduction of amylose and protein content can improve palatability of proso millet in quality breeding.(4)After the removal of albumin,globulin and glutelin,the large starch–protein complex was destroyed,a large number of starch particles were free,and the samples were dispersed as small particles.However,the removal of prolamin had little effect on the structure of proso millet powder.The gel consistency of proso millet powder with glutelin and prolamin removed was significantly improved.The peak viscosity,final viscosity and damage value of proso millet powder with albumin,globulin and glutelin removed were significantly improved,and glutelin was the most improved,followed by globulin and albumin.The removal of prolamin significantly reduced the peak viscosity,damage value and recovery value of proso millet powder.Glutelin and prolamin had the greatest influence on gelatinization properties and showed negative correlation between them.To sum up,proso millet protein is rich in essential amino acids and is an excellent source of plant protein.The water absorption,oil absorption and emulsifying capacity of proso millet with higher protein content were significantly better than those of proso millet with lower protein content.Proso millet with high amylose and protein content has poor cooking performance,high energy consumption and long cooking time.Glutenin and prolamin had the greatest impact on the eating quality of proso millet.