| Corn is a common crop in daily life.Not only does it have high yield and rich nutrition,but it has good stress resistance and strong adaptability in the harsh environment of drought,cold and barren.However,in terms of application,due to the lack of gluten protein inside the corn,the viscosity after mixing with water is poor,leading to the low effectively of forming a tough dough,which affects the processing and utilization,and restricts the possibility of further application.Lactic acid bacteria have attracted more and more attention in food quality improvement.In this study,corn was used as raw material and fermented by lactic acid bacteria to improve the processing performance of corn flour.In a single-factor experiment with corn dough viscosity as an indicator,after the optimization of corn flour lactic acid bacteria fermentation process,here comes the conclusion:The best fermentation process of corn flour lactic acid bacteria was:temperature at 37 ℃,fermentation time at 96 h,inoculation amount at 25%,the initial p H value of the culture medium at 6.5,and the ratio of material to liquid is 1.5 : 1(g : m L).From the results of the response surface test,the significance of the influence of various factors on the viscosity of the corn dough ranks from highest to lowest: the ratio of material to liquid>fermentation temperature>initial p H of the medium>fermentation time.Under the optimal conditions,the viscosity of corn flour fermented by lactic acid bacteria was 1.84 times of the original level(7.3 ± 0.04).After fermentation,the water-holding capacity of corn flour decreases as the gelling power increases;The attenuation value and retrogradation value of the fermented corn flour decreased during the gelatinization process,and the relative starch content of fermented corn flour increases,so its gelatinization properties are closer to starch,with better thermal stability and resistance to retrogradation.The results showed that in addition to the relative increase in starch content,the content of each nutrient component is reduced to varying degrees;fermentation improves the ordering of protein molecular arrangement and structural stability;starch molecules appear due to the increase in amylose content More hydrogen bonding,which in turn improves its cohesiveness.Compared with the original corn noodles,the texture,taste and structure of the whole corn noodles were greatly improved.The whole corn noodles had lower hardness,more elastic taste,chewiness and higher sensory quality.In terms of texture characteristics,the chewiness,hardness,viscosity and elasticity of fermented noodles were significantly better than those of non fermented noodles.In conclusion,fermentation can significantly improve the processing applicability of corn flour,which provides a theoretical basis for promoting the large-scale production of corn food through fermentation in the future. |
