An improved process of hydrolysis of corn starch was adopted in the production of itaconic acid(IA),the aim was to decrease the unfermentable reducing sugar (RS) in the medium from the beginningof the fermentation and to increase the crystallization efficiency of IA from the fermentation broth.Theglucose (GS) syrups saccharified by several combinations of glucoamylase and pullulanase were investi-gated and used as the carbohydrate source of the fermentation medium for the spore-initiated submergedfermentations experiments.Compared with the conventional process (with ptdlulanase controlled),theimproved process decreased the RS residue in the fermentation broth from 3.01g/L to 1.35g/L and from4.25g/L to 3.25g/L when the original RS of the medium were 100 and 120g/L,respectively.The crys-tallization efficiency of IA increased from 65 % to 78.8 % and from 69.58 % to 82.81% with the originalRS being 100 and 120g/L,respectively.
Lactic acid bacteria (LAB) were encapsulated with alginate, gelatin and trehalose additives by the extrusion method and dried at 4 ℃. The microcapsules were generally spherical and had a wrinkled surface with a size of 1.7 mm ± 0.2 mm. Trehalose as a carbohydrate source in the culture medium could reduce acid production and performed no function in the positive proliferation of LAB. Using trehalose as a carbohydrate source and protective medium simultaneously had a benefit in the protection of LAB cells during the storage at 4 ℃. The density of live LAB cells could be 107 CFU g-1 after 8 weeks of storage. Cells of LAB could be continuously released from the capsules from the acidic (pH 1.2) to neutral conditions (pH 6.8). The release amounts and proliferation speeds of LAB cells in neutral medium were much larger and faster than those in acidic conditions. Additionally, immobilization of LAB could improve the survival of cells when they were exposed to acidic medium (pH 1.2) with a survival rate of 76 %.
Chitosan andβ-cyclodextrin were used to prepare microspheres with theophylline for pulmonary delivery by spray drying method.The characteristics,mucociliotoxicity,permeation rate and drug release were studied.The drug entrapments of microspheresⅠ,ⅡandⅢ were from 35.70%to 21.09% and 13.33%,while yields and encapsulation efficiencies were higher than 45% and about 90% respectively. The microspheres possessed low tap densities(0.34-0.48 g/cm3),appropriate diameters(3.35-3.94μm)and theoretical aerodynamics diameters(2.20-3.04μm).SEM images showed the microspheres were spherical with smooth or wrinkled surface surfaces.FT-IR demonstrated theophylline had formed hydrogen bonds with chitosan and β-cyclodextrin.The microspheres could effectively reduce the ciliotoxicity and easy to penetrate the memberine.The in vitro release of the microspheres was related to the ratio of drug/polymer and microspheresⅡ had a prolong release,providing the release of 72.00%in 12 h.The results suggestes that chitosan/β-cyclodextrin microspheresⅡare a promising carrier as sustained release for pulmonary delivery.
A coacervation method with double emulsion strategy (w/o/w) was used to prepare immobilized Lactobacillus E1. Diatomite was chosen as the carrier for bacteria. Sodium alginate, dextrin and gelatin were used as protective solutes for the preservation of Lactobacillus E1 and their effects on the storage viability during storage were discussed. The influence of storage temperature on the storage viability was also examined. The results show that high bacteria viable count over 109 cfu/g for an extended shelf life of 37 d can be achieved with 2% sodium alginate, 5% dextrin and 4% gelatin as protective solutes, at 10 ℃ of the storage temperature. This immobilized Lactobacillus E1 has potential use as functional food ingredient for both human dairy food and animal feedstuff.
