| Konjac glucomannan(KGM)is a natural polysaccharide polymer,has good gel property,water solubility,biocompatibility,biodegradability,has important applications in the field of immobilizing drugs,enzymes,microorganisms.Taking L.acidophilus as the research object and KGM as material,the paper made use of the adsorption of KGM gel to immobilize L.acidophilus,improving the encapsulation yield of microencapsulation of L.acidophilus.Meanwhile,microspheres were reinforced by bending with Konjac Oligosaccharides to improve extra protection for L.acidophilus.The main research contents and results were as follows:1.Using sodium periodate oxidation modified KGM to prepare Dialdehyde glucomannan(DAK),DAK and gelatin crosslinking reaction to form DAK/gelatin crosslinked gel.Based on the single factor experiment,the optimum process parameters using response surface methodology were obtained as follows:total concentration was 9.46%,the ratio was 2:1,the crosslinking reaction temperature was 50.91?,the crosslinking reaction time was 1.43h,under this experiment,the DAK/gelatin crosslinked gel strength was 222.1g.Scanning electron microscopy showed that:DAK/gelatin crosslinked gel within a large number of interconnected pore structure,pore wall was thick and smooth,and there is significant channel formation.2.Using freeze-drying technology and ultrafine grinding technology to prepare the porous KGM/gelatin gel particles.Taking porous KGM gel particle which absorbed and fixed L.acidophilus as the core material and sodium alginate as the wall material,microencapsulation of L.acidophilus were prepared by emulsification.Take the embedding rate as detection index,based on the single factor experiment,the optimum process conditions of porous DAK/gelatin crosslinked gel particles to adsorb and immobilize L.acidophilus was tested by orthogonal experiment.The result showed that:the porous KGM/gelatin gel particles dosage was 1.5g,sodium alginate solution concentration was 3%,sodium alginate solution/soybean oil volume ratio was 1:5,emulsification speed was 1250rpm,under this conditions the highest microencapsulation rate was 62.5%.3.The results of L.acidophilus microcapsules storage stability showed that:microencapsulation L.acidophilus storage period is longer than the freeze-dried powder,L.acidophilus microcapsules storage stability at 4? is better than 25? the storage of freeze-dried microcapsules was longer than wet microcapsules.However,during the freeze-drying process,even microencapsulation L.acidophilus,there were still a large number of bacteria death,viable cell count by 10.07log CFU/g dropped to 9.67log CFU/g.4.Using ?-mannanase enzyme KGM to prepare Konjac oligosaccharides(KO).Take the KO complex with sodium alginate as a microcapsule wall material.Research on the effect of KO on the microencapsulation L.acidophilus anti-freeze drying capacity and strengthen the resistant role of gastric acid.The result showed that:during the freeze-drying process,8%(w/v)KO adding improved the L.acidophilus microcapsules survival by 63.51%to 79.34%,after 2h digestion in simulated gastric fluid,without microencapsulated of L.acidophilus,viable cells decreased 4.08 log CFU/mL,with microencapsulated of L.acidophilus,the decrease amount of viable cells were decreased.The KO adding also strengthen the acid resistance of microcapsule,as compared to pure alginate microcapsules,the decrease amount of viable cells reduced 0.22 log CFU/mL.5.The result of L.acidophilus microcapsules enteric test showed that:In the simulated intestinal fluid,with the extension of digestion time,the absorbance and viable count also increases,after 45min,there was no microcapsule particles left in the solution.Therefor,the L.acidophilus microcapsules prepared in this article have good enteric,can successfully through the stomach to play a probiotic role in the intestine. |
PDF Full Text Request