Preliminary Study And Application Of Pickering Phenomenon Of Corn Flour Processed By Lactobacillus Rhamnosus

Lactobacillus rhamnosus as a probiotic starter has good potential in improving texture and improving nutritional quality of dough.The effect of lactic acid bacteria treatment on physicochemical properties,apparent structure and fermentation properties of corn flour were systematically evaluated.The micromorphology of Pickering foam system in dough was observed.The effect of lactic acid bacteria treatment on the formation and stability of Pickering foam system based on paraffin oil / water two phase simulation system was discussed.The relationship between Pickering system and dough expansive properties were studied by studying the stomatal characteristics of dough / corn steamed sponge cake.The concrete results are as follows:With the time prolong,the physical and chemical properties of corn flour treated with Lactobacillus rhamnosus was changed,the content of fat and damaged starch decreased gradually,the content of protein and amylose increased.The particle size of corn flour was smaller than the control,and the grain size decreased first and then increased with treatment time prolong.After 48 h treatment,the particle size decreased to the minimum of 72.88 ?m;the gelatinization enthalpy increased significantly,and the initial gelatinization temperature and peak temperature decreased slightly.The rheological,expansion and gas holding properties of corn dough treated by Lactobacillus Rhamnosus were observed with rheometer and rheofermentometer.The modulus of energy storage(G')and loss modulus(G'')of corn dough treated by Lactobacillus Rhamnosus were significantly higher than that of the control group,and reached maximum in the treatment of 48 h,the viscoelasticity enhanced.The dough loss tangent(tan?)was less than 1,forming a weak gel viscoelastic system,and the expansive properties of corn dough treated greatly increased.Compared with the control group,the maximum gas release of the dough in the treatment group increased by 45.2%,the total volume of the release increased by 42.93%,the maximum release time of the dough was shortened,and the minimum gas holding capacity increased by 52.8%.The microscopic structure of the dough was observed by the optical microscope.Unlike the control group,the stone-wall structure was similar to the Pickering system in the corn dough of the treatment group.Based on the paraffin oil / water simulation system,the microstructure of the system was observed by optical microscope,and the stability of the system was measured by the droplet size.The effect of Lactobacillus rhamnosus treatment on the formation and stability of Pickering foam system of corn flour were investigated in terms of particle concentration,pH and processing time.The particle size increased from 5% to 40%,and the size of the treated system decreased significantly and the stability increased.In the control group,the particle size decreased to a certain extent.The water phase pH of the control group was 3 to 8,the size of droplets decreased significantly.When pH is 10,the droplets size will increase and Pickering will appear under strong acid / alkali conditions.The particle size of corn flour increased and then decreased with the prolongation of Lactobacillus rhamnosus treatment time,and reached the maximum at 48 h.The stability of the treatment system was better than that of the control group,and the corn flour covered with the droplet surface could be gelatinized directly to form a shell like network structure in high temperature.The effect of Lactobacillus rhamnophilus on the formation of Pickering system and its effects on the improvement of the quality characteristics of corn flour were evaluated by measuring the specific volume and the size and proportion of the stomata of the corn steamed sponge cake.Compared with the control,the specific volume of the cake made from corn flour treated 48 h was the largest,up to 2.63 mL/g,and increased by 11.5%.The size of the stomata and the proportion of stomata in the corn steamed sponge cake were significantly increased.The specific volume and stomatal cross section ratio were significantly correlated with the droplet size of the two phase simulation system,the r values were 0.9966 and 0.9631 respectively.Therefore,the appearance of Pickering is conducive to maintaining and stabilizing the stomata of dough.The fermentation of Lactobacillus rhamnosus increased the hardness,improved springiness and enhanced chewiness of corn steamed sponge cake.