【作者】 孙莹；

【导师】 张连富；

【作者基本信息】 江南大学 ， 农产品加工与贮藏， 2008， 硕士

【摘要】 番茄红素是一种重要的功能性脂质体,具有淬灭单线态氧和清除过氧化自由基、调控肿瘤细胞增殖等多种生物学作用,但由于具有较强的疏水性,限制了其使用范围。采用纳米技术制备番茄红素纳米分散体,增大了番茄红素与胃肠道细胞的有效接触面积,从而提高其吸收率和生物利用率,这对于改善番茄红素的水溶性具有重要的意义。本论文对番茄红素纳米分散体的制备工艺进行了研究,选用有机溶剂溶解/混合乳化/溶剂蒸发的方法制备得到了粒径分布范围在90-250 nm之间的番茄红素纳米分散体,并对番茄红素纳米分散体的稳定性进行了初步探讨。研究的主要内容包括:首先以产品色泽和粒径分布为指标探讨了番茄红素纳米分散体的配方工艺。在乳化剂Tween-20,乳化剂用量0.5%(W/W),有机溶剂乙酸乙酯,有机相:水相比例2:8(V/V),番茄红素含量0.7 %(W/W)的条件下,制备得到番茄红素纳米分散体的Z-均粒径为93.87 nm,分散性较好。产品在冰箱贮存120 d,其粒径大小与分布与初始样品相比各项统计指标均无显著性变化,相当稳定。比较了超声乳化法、高速剪切乳化法对番茄红素纳米分散体的影响,并选定了超声乳化作为产品的纳米化方法。然后以吸光度变化率、产品色泽和粒径分布为评价指标对超声各工艺参数进行了优化:当超声功率为468W(总功率650 W的72 %),超声时间3 s,超声间隔时间2 s,超声总时间4.2 min时,超声2次,此时产品的粒径可达113.56nm,吸光度变化率为4.98 %。根据在不同超声功率下得到产品的粒径分布得出Z-均粒径和超声功率具有较好的相关性,随着超声功率的增大,产品的Z-均粒径随之减小。由于体系在不同的纳米级别可能具有不同的性质,因此可以通过控制生产的工艺参数来获得所期待粒径分布范围的纳米级别产品;Z-均粒径和吸光度变化率也有一定的相关性,因此采用吸光度变化率作为评价指标是有一定可行性的。采用HPLC测定番茄红素纳米分散体样品中的番茄红素浓度为48.70μg/mL,采用顶空进样法测定样品乙酸乙酯的残留量为6.853μg/mL,远远小于国家标准。对样品的稳定性进行研究,发现番茄红素纳米分散体对光敏感,在不同光照条件下,番茄红素纳米分散体的保留率均高于番茄红素普通制品;温度越高对番茄红素纳米分散体的稳定性影响越大;氧化剂H2O2对番茄红素纳米分散体稳定性的影响很大,氧化剂的浓度越高,对其影响越大;抗坏血酸并没有起到稳定番茄红素纳米分散体的作用,反而在一定条件下具有促氧化作用。除了Fe3+、Cu2+、Al3+外,Mg2+、Fe2+、Na+、K+等金属离子对番茄红素纳米分散体稳定性的影响不大。防腐剂山梨酸钾和苯甲酸钠、糖类和柠檬酸等常见食品添加剂对番茄红素纳米分散体的稳定性影响很小。更多还原

【Abstract】 lycopene known as an important functional lipid ,has many biological activities such as quenching singlet oxygen, eliminating peroxyl-radicals and regulating tumor cell proliferation. however the poor water solubility of lycopene has limited their using range. Nanotechnology provides a good opportunity to improve the solubility of such functional lipids. Particles in the nanometer range increase effective contact area of gastrointestinal cells, which should lead to improved absorptivity and bioavailability. This paper focuses on the preparation and stability of lycopene nanodispersion, Z-average diameter of lycopene nanoparticles, ranging from 90 to 250 nm by emulsification-evaporation was observed. Its main contents are described as follow:The formula of lycopene nanodispersion was studied through orthogonal experimental methodology. The results showed if Tween-20 was used as emulsifier at a dosage 0.5%(W/W),ethyl acetate was used as organic solvents and the ratio of organic/aqueous phase was controlled at 2:8, the lycopene content in nano-dispersion was 0.7%(W/W),the Z-average diameter of the lycopene in the sample was around 93.87nm.After the observation in 120 days, the remarkable change of the particle size and distribution of lycopene nanodispersion did not arise.It was quite stable.The emulsification-evaporation process of lycopene nanodispersion was also studied. Firstly, We choose the ultrasonic emulsification as nano-prepared method by compared ultrasonic emulsification and high speed distribution on the effect of lycopene nanodispersion. Then optimized the processing technology using absorbance change rate, color and particle size as evaluated index was obtained .The final parameters were as follows: ultrasonic power 468 W, as 72% total power, ultrasonic time 3 s, ultrasonic total time 4.2 min, ultrasonic interval time 2 s, 2 times. The Particle size was 113.56 nm, absorbance change rate was 4.98 %.The Z-average particle size and ultrasonic power showed a good correlation according to particle size obtained by different ultrasonic power. The Z-average particle size decrease with the rise of the ultrasonic power. As different properties may in different nano-sized grade, a desired particle size distribution can be produced in a controlled way by varying the production parameters. It is shows the relationship between Z-average particle size and absorbance change rate. So it is possible using absorbance change rate as evaluated index.The concentration of lycopene nanodispersion assayed by HPLC was 48.7μg/mL, the residual content of Ethyl Acetate of sample was 6.853μg/mL, less than national standard. As for stability of lycopene nanodispersion research, we found it was sensitive to light. The retention rate was far than common lycopene under different light conditions; the higher temperature was, the lower the stability of lycopene nanodispersion; the effect of oxidant on stability of lycopene nanodispersion was big; Vc had little effect on stability of lycopene nanodispersion, conversely has promoting oxidation on certain condition; Metal ions, such as Mg2+、Fe2+、Na+、K+ except Fe3+、Cu2+、Al3+ had little influence on stability of lycopene nanodispersion. The effect of preservative, glucose and citric acid on stability of Lycopene Nanodispersion was very little更多还原