Process Study And Quality Analysis Of Enrichment Of Corn Laozao Residue γ-aminobutyric Acid

As an important food crop,corn has abundant yield and high nutritional value,but its related product development is limited.Using corn as raw material,this paper studies and optimizes the process conditions of stress germination combined with fermentation and enrichment of γ-aminobutyric acid(GABA).At the same time,different drying methods were used to treat the germinated maize under stress,and the changes of nutritional indexes and physical characteristics of germinated maize flour were studied.Takingγ-aminobutyric acid as the index,the saccharification and fermentation conditions of laozao residue were optimized.The main results are as follows:(1)The germination conditions of maize enriched with GABA were studied by univariate combined response surface experiment.Through the results of single-factor test,it can be seen that the germination days were 3d,the germination temperature was 35°C,the ultrasonic power was 300 W,the germination was 1d after ultrasonic treatment for15 min,and then germinated by 150mmol/L Na Cl stress for 2d,and after vacuum treatment for 6h,the GABA content of germinated corn was the highest.The optimal process conditions obtained by the GABA response surface test of germinated maize enrichment were as follows: soaked maize,after germination with a power of 300 W and ultrasonic treatment for 14.4min for 1d,it continued to germinate for 1.3d under Na Cl concentration of 129mmol/L,and then after 6.4h vacuum treatment,the GABA content reached up to45.86mg/100 g.(2)To study the changes of nutrients,color,thermodynamic properties,viscosity characteristics,swelling power and solubility of ultrasonic,Na Cl and vacuum stressed germinated corn flour under different drying methods.The results showed that the color of germinated corn flour under ultrasonic and Na Cl treatment decreased,the gelatinization temperature increased,the viscosity,regeneration value and light transmittance decreased,and the swelling power and solubility increased.Freeze-drying germinated corn flour has high color,viscosity,low regeneration value,light transmittance,swelling power,and large solubility.(3)The optimal saccharification and fermentation process of corn laozao was studied through single-factor orthogonal experiments.The results showed that the best saccharification and fermentation process for enriching GABA corn laozao was: 20% of saccharified grain koji added,saccharification temperature of 45°C,saccharification time of 48 h,and GABA content of up to 48.31mg/100 g.Under this saccharification condition,fermentation 3d,fermentation temperature 35 °C,yeast addition 1.2%,GABA content up to 54.07mg/100 g,corn laozao made under this condition has high GABA content and good flavor.(4)The effects of ultrasound,sucrose and sodium glutamate on fermentation and enrichment of GABA were studied.It was found that under the condition of 8min ultrasound time,ultrasonic power of 200 W,sucrose addition of 3% and sodium glutamate addition of 0.6%,the GABA content obtained by fermentation 3d was up to 57.63mg/100 g,and there was no significant difference in alcohol,p H,reducing sugar and total acid of laozao residue compared with normal fermentation laozao residue,and ultrasound,sucrose and sodium glutamate could effectively increase the GABA content in corn laozao residue,and did not have adverse effects on the flavor of laozao.