Effect Of The Ratio Of Amylose To Amylopectin In Mixed Flour Of Coarse Cereals On The Quality Of Extruded Noodles

Coarse cereals is a kind of high-quality food with balanced nutrition.It has high protein content and contains a variety of nutrients.However,due to its small molecular weight of gluten and no viscoelasticity,it is not easy to form a structure similar to gluten network in the processing process,which limits the processing of coarse cereals.Noodles,a traditional food,has been loved by people since ancient times.Nowadays,because of its delicious,convenient and nutritious characteristics,people’s consumption demand for flour products is increasing day by day.The large-scale industrialized production of flour products has also attracted extensive attention.Therefore,the development of coarse cereals noodles with good processability and palatability has become a research hotspot in recent years.In order to improve the processability and palatability of coarse cereals,the effect of the ratio of amylose to amylopectin on the processability of coarse cereals was clarified.In this study,buckwheat flour,quinoa flour and mung bean flour were selected as raw materials.Based on the analysis of the physical properties of buckwheat flour,quinoa flour and mung bean flour,the ratio of amylose to amylopectin of the compounded flour was changed by mixing three kinds of flour.Six kinds of hybrid cereals with starch direct branch ratio of 0.119,0.139,0.159,0.179,0.199 and 0.219 were obtained with different proportions of buckwhea flour,quinoa flour and mung bean flour.The texture quality,water distribution,thermal gravity,cross-section morphology and sensory quality of coarse cereals composite powder and coarse cereals composite noodles were measured and characterized by texture analyzer,nuclear magnetic resonance analyzer,rheometer,thermogravimetric analyzer,scanning electron microscope(SEM)and sensory evaluation.With the increase of the ratio of amylose to amylopectin,the solubility index and water absorption index of hybrid grain powder increased,the peak temperature increased from67.23℃ to 71.44℃,the gelatinization enthalpy increased from 1.38 J/g to 2.85 J/g,and the thermogravimetric weight loss rate and maximum weight loss temperature increased significantly.The cross section of coarse cereals noodles showed a more compact structure with the increase of the ratio of amylose to amylopectin,and the hardness and chewability increased with the increase of the ratio of amylose to amylopectin.The dry matter water absorption of coarse cereals noodles increased from 52.23% to 62.37%,and the cooking loss rate decreased from 13.21% to 7.35%.In vitro digestibility and glycemic index reached the lowest when the ratio of amylose to amylopectin was 0.199.Through single factor and optimization experiments,taking sensory score and cooking quality as indicators to determine the range of better process parameters,and taking principal component analysis as the main analysis method,it is concluded that the first comprehensive score value is the mixed grain noodle with the ratio of amylose to amylopectin is 0.199,moisture content of27%,extrusion temperature of 90℃ and screw speed of 68 r/min.Due to the compounding of coarse cereals flour,the ratio of amylose and amylopectin in the compounded coarse cereals flour was changed,and the processing characteristics and palatability of coarse cereals were improved,which provided a new idea for the development of new products of mixed coarse cereals.