Construction Of Defatted Soybean Nanoparticle Based Nutritional Delivery System Of β-carotene

β-carotene is the most important pro-vitamin A, and has anti-oxidation, anti-tumor actiivity. β-carotene are broadly used in food industry and pharmaceutical preparations as colorants and nutritional supplements. However, β-Carotene is also highly prone to oxidative degradation due to its environmentally sensitive in practical applications. Furthermore, β-carotene has poor solubility in water, which limits its applications. Therefore, defatted soybean nanoparticle was use to package and carry β-carotene, improving its stability and bioavailability. Defatted soybean is a byproduct of soybean after extraction of oil. The content of crude protein in defatted soybean is up to 30%~50%, which is one of the main animal protein feeding. Defatted soybean nanoparticle was obtained after the nano processing, which provide a new possibility for the nutrient carrying in foods, especially for insoluble nutrients, such as β-carotene. Soybean is food material; its safety is undoubted. In addition, defatted soybean nanoparticle can form aggregations, which are stable in solution. This made it feasible to construct a nutrition delivery system to carry β-carotene by defatted soybean nanoparticle.This work included three parts, as following: the observation on defatted soybean nanoparticle aggregation and the binding force between defatted soybean nanoparticle and β-carotene, screening on method for β-carotene quantitation, characterization on defatted soybean nanoparticle based nutritional delivery system of β-carotene.To prepare the nanoparticles, a ball mill was used to grind defatted soybean, till the nanoparticle diameter was about 200 nm. The p H value, salt concentration and storage time was selected by the single factor experiment. Combined with response surface methodology and particle size analyzer, the effect of the three factors on the defatted soybean nanoparticle aggregation was studied. By Response surface analysis, the experimental data indicated that the the defatted soybean nanoparticle aggregation firstly effected by pH value, followed by storage time, the effection of salt concentration is not obvious. Moreover, pH and [NaC l], p H and storage time have a significant interaction effect. Infrared spectroscopy detected the peak of β-carotene, defatted soybean nanoparticle, β-carotene and defatted soybean nanoparticle underdifferent concentrations. The results showed that β- carotene and defatted soybean nanoparticle combined mainly by hydrogen, which was consistent with the results that p H value influenced the defatted soybean nanoparticle aggregation.In the work of screening on method for β-carotene quantitation, four detection method(UV method, extraction-UV method, HPLC method and extraction-HPLC method) were evaluated. The results show that using extraction-HPLC method to detect β-carotene takes great advantage, with the wide linear range, better accuracy and lower detection limits. This method is suitable for β-carotene quantitation in our delivery system.Research also characterized the carrying efficiency and loading efficiency of defatted soybean nanoparticle delivery system. Extraction-HPLC method was used for determination the content of β-carotene in delivery System. Carrying efficiency and loading efficiency at different concentrations ratios was measured in the experiments. The results showed higher carrying capacity under the conditions of β-carotene and defatted soybean nanoparticle concentration ratio 0.03:0.01, 0.02:0.01, 0.05:0.05, 0.05:0.1, 0.05:0.15. Under same concentrations ratio, lower β-carotene concentration has a higher combined rate.Scanning electron microscopy was used to observe morphology of β-carotene, defatted soybean nanoparticle and the delivery system. The results showed that most defatted soybean nanoparticles were spherical, β-carotene exhibit square crystals. After carrying the β-carotene and aggregated, the shape of defatted soybean nanoparticle and β-carotene changed, diameter of defatted soybean nanoparticle aggregation increased from 200 nm to 1000 nm.During the stability characterization, three storage conditions were set:(1) 4℃in dark;(2) 25℃ in light;(3) 25℃ in UV. The retention of β-carotene in delivery system was quantified by UV spectrophotometry during the storage. The results showed that the retention of carried β-carotene was much higher than the free one after 15 days. The β-carotene carried by defatted soybean nanoparticle may be protected from the influence by environmental conditions.To carry β-carotene, the defatted soybean nanoparticles were prepared by grinding. The defatted soybean nanoparticle delivery system can protect β-carotene againstroom temperature, ultraviolet light damage. In this thesis, food particle was used as carrier material for the first time, although the uniformity of the delivery systems remained unsatisfied.