Studies On Solid State Fermentation Assist Cold Pressing Technology To Extract Oil

Solid state fermentation assist cold pressing technology compared with hot pressing and solvent extraction process avoided the solvent residual problem,and got a high oil extraction rate,and makes the cake has good processing properties,which is a kind of healthy and efficient technology of oil extraction methods.This paper screening the strains firstly with the activity of lipase、cellulase、protease as the evaluation index,target strains should have low lipase activity but high cellulose activity and high protease activity,after screening,got that the cellulose activity and the protease activity of Tempeh are higher than Bacillus natto and Aspergillus oryzae,at the same time the lipase activity of Tempeh is lower the two the others,suitable to be the preprocessing strains.Under above conditions,further to through the mutagenesis experiment,to further improve the Tempeh activity of cellulase and protease,then the fermentation conditions and the nutrients of the substrate is optimized,got the following results.This paper uses Rhizopus oligosporus as the zymocyte(Commonly known as Tempeh)to process the oil material,optimizing the parameters of the experiment through the single factor experiment and orthogonal response surface method,got the optimum technology parameter that the optimal fermentation temperature is37.23℃,the optimal moisture content in the matrix is29.96%,the optimal fermentation time is49.16h,the optimal inoculum dose is8.01%.The optimal components of the elements ion in matrix is:Mg2+(25.30mg/kg)、Zn2+(10.36mg/kg)、Fe2+(5.55mg/kg)、K+(14.95mg/kg), after the optimizing of fermentation conditions and the composition of ions in the matrix,the activity of cellulase and protease reach7219.25U/ml and1743.96U/ml respectively。After the optimizing of fermentation conditions and the composition of tons in the matrix, go on to study the fed-batch process got that the method of fed-batch:choose glucose as the carbon source,choose peptone as the nitrogen source,the initial additive amount of carbon source and nitrogen source are4%and0.5%separately,than add carbon source and nitrogen source gradually,the way for adding carbon source is a two-stage process,when fermenting taking on to12h,add the carbon source for the first time,adding carbon source content to account for6%of the dry weight of the substrate,when fermenting taking on to24h add the carbon source for the second time, Adding carbon source content to account for8%of the dry weight of the substrate;the way for adding carbon source is a three-stage process,when fermenting taking on to12h,add the nitrogen source for the first time,adding nitrogen source content to account for1%of the dry weight of the substrate,when fermenting taking on to24h,add the nitrogen source for the second time,adding nitrogen source content to account for1.5%of the dry weight of the substrate,fermenting taking on to36h,adding nitrogen source content to account for2%of the dry weight of the substrate.Under above conditions,the activity of cellulase and protease reaches11016U/ml and2610U/ml separately.After fermentation,the oil extract rate reaches73.6%,higher than the team without pretreatment that the percent is11.6,the oil need no more refine can got the tertiary oil standards,and the NSI of the cake reaches37.6%,prove that the cake still keep the good processing property.