姜黄素茶油乳液的制备及其特性

为了提高姜黄素(Cur)的稳定性、溶解度和生物利用度,实验利用茶油乳液对Cur进行包埋,并对乳液的粒径、流变特性及贮藏稳定性进行系统研究.实验结果表明,当吐温80:无水乙醇=2∶1、茶油:表面活性剂=1∶4时,负载Cur(0.1wt％、0.13wt％、0.17wt％)的茶油乳液最稳定,平均粒度分别为(504.5±12....     

Inverse Emulsion of Starch‐graft‐Polyacrylamide

An inverse emulsion of cationic starch‐graft‐polyacrylamide was prepared by inverse emulsion polymerization and a subsequent Mannich reaction. The copolymerization was carried out using potassium persulfate as initiator. The reaction conditions and factors affecting emulsion stability were studied. Experiments showed that a high solids content, a high cationic degree and a stable latex can be obtained under the following condition: A molar ratio starch/acrylamide/formaldehyde/dimethylamine of 0.11:1:1:1.2; a stable inverse emulsion system; graft copolymerization of starch and acrylamide for 2‐3 h at 50 °C; pre‐formation of an aldehyde‐amine adduct, which is subsequently dropped into an inverse emulsion of starch‐graft‐polyacrylamide. The reaction temperature was 45 °C, the reaction time was 3‐4 h, and the pH was 5.5.     

Oxidation Stability of O/W Emulsion Prepared with Linolenic Acid Enriched Diacylglycerol

The sn‐1,3‐regiospecific Rhizomucor miehei lipase (Lipozyme RM IM) was employed to produce structured diacylglycerol (SL‐DAG), which contained 67.3 mol% DAG with 27.2 area% of C18:3. To investigate the oxidative stability of the SL‐DAG in emulsion form, 5% oil‐in‐water (O/W) emulsions were prepared with 200 and 400 ppm sinapic acid. It was shown that the hydroperoxide values of the control (without any antioxidant) was the highest (117.7 meq/L) on day 43 of storage and thereafter the value decreased. However, the emulsions with 200 and 400 ppm sinapic acid resulted in slow oxidation degree until day 64 of storage (30.3 and 7.3 meq/L, respectively). Aldehyde measurements for the 200 ppm sinapic acid emulsion (12.8 mmol/mol) and the 400 ppm sinapic acid emulsion (7.5 mmol/mol) also showed better oxidative stability than that for the 200 ppm catechin emulsion (27.4 mmol/mol) and the control (52.7 mmol/mol). Although the SL‐DAG in the emulsions contains high levels of polyunsaturated fatty acids, the degree of oxidation in the emulsions can be reduced when sinapic acid is used as an antioxidant.     

磷脂茶多酚复合物的制备及其对淡水鱼松的抗氧化作用

为提高淡水鱼松贮藏期,合成了磷脂茶多酚复合物(TPP-PL),研究其溶解性、缓释性、抗氧化性以及对鱼松贮藏期间过氧化值及脂肪酸成分的影响。结果表明,磷脂包覆能有效提高茶多酚(TPP)的亲脂性,在氯仿-水和乙酸乙酯-水体系中,TPP-PL的分配系数K值分别达到150.8和21.33;TPP-PL缓释性更佳,其体外释放模拟试验24 h的TPP释放率仅为24%±3.6%,能与鱼松结合并持久释放TPP;同时,TPP和TPP-PL的抗氧化能力存在剂量效应,两者的DPPH自由基清除能力差异不大,而TPP-PL铁离子还原力则略低于TPP。将TPP单体与TPP-PL分别应用于鱼松后发现,经TPP-PL处理的鱼松过氧化值上升较TPP处理的鱼松过氧化值缓慢,贮藏20 d后,后者的过氧化值比前者高50 meq/kg;鱼肉在炒制成鱼松后因热氧化作用导致不饱和脂肪酸含量减少,饱和脂肪含量增加,而添加TPP-PL的鱼松在炒制过程中硬脂酸增量和亚油酸减量仅为1.46%和4.29%,均显著小于TPP单体鱼松硬脂酸和亚油酸的变化。TPP-PL能长效保护鱼松炒制和贮藏过程中的脂质氧化,延长鱼松保质期,维持鱼松营养性,具有良好的开发利用价值。     

Study on Preparation and Thickening Efficiency of an Inverse Emulsion of Anionic Starch‐graft‐Polyacrylamide

A series of graft copolymers of starch with polyacrylamide was made by using a K₂S₂O₈ initiation system in inverse emulsion. The corresponding anionic graft copolymers, which have a different hydrolysis degree, are prepared by alkaline hydrolysis of the uncharged graft copolymers. Adequate hydrolytic conditions including type and amount of hydrolyzing agent, temperature, and time were studied. These graft copolymers have been tested for their temperature sensitivity, salt tolerance and shear stability, and a comparison has been made with ungrafted polyacrylamide (PAM). Experiments showed that a high hydrolysis degree can be obtained in a shorter time when NaOH and Na₂CO₃ were used together as hydrolyzing agents, and the highest solution viscosity was observed when the hydrolysis degree of the graft copolymers was approximately 30%, . In addition, the shear stability, temperature sensitivity and salt tolerance in the graft copolymers were also investigated.     

Antioxidant Properties of Aqueous Extract of Roasted Hulled Barley in Bulk Oil or Oil‐in‐Water Emulsion Matrix

Antioxidant properties of the aqueous extracts of hulled barley (Hordeum vulgare L.) that had been roasted at 210 °C for 20 min were determined in bulk oil and oil‐in‐water (O/W) emulsions. Bulk oils were heated at 60, 100, and 180 °C, and O/W emulsions were oxidized under riboflavin photosensitization. The content of phenolic compounds was analyzed by high‐performance liquid chromatography, and in vitro antioxidant assays were also conducted. The major phenolics contained in the aqueous extract of roasted hulled barley (AERB) were p‐coumaric, ferulic, protocatechuic, chlorogenic, 4‐hydroxybenzoic, and vanillic acids. Depending on the concentration and oxidation temperature, AERB had antioxidant or prooxidant properties in bulk oil. At 60 °C, AERB at a concentration of 0.5% acted as a prooxidant, whereas at 1.0% it acted as an antioxidant. At 100 °C, AERB acted as an antioxidant irrespective of concentration. In 180 °C conditions, 0.5% AERB acted as a prooxidant, whereas other concentrations of AERB acted as antioxidants. In the case of riboflavin photosensitized O/W emulsions, AERB showed antioxidant properties irrespective of concentration. Antioxidant abilities of AERB are affected by the food matrix, including bulk oil and O/W emulsions, and concentrations of AERB, even though diverse phenolic compounds may display high antioxidant properties in in vitro assays.     

脂溶性茶多酚制备工艺的研究

本试验以乙酸酐为酰化剂对茶多酚乙酰化从而增强其脂溶性,以衡量脂溶性的产物透光率为参数。在分析乙酰化中料液比、吡啶催化剂用量、反应温度、时间等单因素对产物性能影响的基础上,利用响应面分析法优化了脂溶性茶多酚制备的条件并建立了可靠的多元二次回归模型。结果表明,当料液比为1∶8.03,催化剂用量为0.31 g,在61.3℃下回流反应1.93 h,改性茶多酚透光率达到了1.000,为茶多酚对照组的2.08倍。其油脂抗氧化保护系数为6.576 d,DPPH·抑制率0.922 1,分别提高了2.14倍和2.98倍。与丁基羟基茴香醚(BHA)与特丁基对苯二酚(TBHQ)相比,改性茶多酚的保护系数和DPPH·抑制率分别提高3.1倍、2.5倍、1.07倍、1.05倍。     

基于食用油为连续相的茶多酚反相微乳液的制备

制备油烯基聚氧乙烯（10）醚（polyoxyethylene (10) oleyl ether,Brij97）-单油酸甘油酯（glyceryl monooleate,GMO）-乙醇-食用油-水反相微乳液,成功将抗氧化剂茶多酚添加至食用油中。通过拟三元相图法、动态光散射法和差示扫描量热法研究微乳液的相行为、粒径和抗氧化能力。结果显示,微乳液的最佳配方条件为复合表面活性剂Brij97与GMO质量比2∶8、水相中水与乙醇质量比4∶1。微乳液中茶多酚质量浓度越高,微乳液粒径越小,但多分散指数越大。当水相中茶多酚质量浓度达到0.10?g/mL时,30?d内5?种微乳液粒径都稳定在8.00～12.00?nm范围内。差示扫描量热法显示空白大豆油微乳液的起始氧化温度为163.40?℃,添加0.01?g/mL茶多酚后为175.77?℃,添加0.10?g/mL茶多酚后为210.88?℃。     

甘草酸纤维茶树精油乳液凝胶的制备及其结构表征

选取茶树精油为风味油相,利用甘草酸自组装纳米纤维作为结构单元构建风味精油乳液凝胶体系,研究甘草酸纤维质量分数、茶树精油质量分数、油相组成对精油乳液凝胶外观、微观结构、流变学特性的影响.结果表明:利用甘草酸的两亲性和纤维化自组装,能成功制备出乳滴粒度小(2.5μm)且具有蜂窝状网络微结构的茶树精油乳液凝胶;流变学测试显示...     

乳化剂对茶多酚和脂溶性茶多酚抗亚油酸及其乳化体系氧化作用的影响

本文研究了茶多酚和脂溶性茶多酚对亚油酸及其乳化体系抗氧化作用的影响,结果发现茶多酚和脂溶性茶多酚联合处理组在亚油酸及其乳化体系中的抗氧化作用都显著优于茶多酚和脂溶性茶多酚单独处理组。进一步研究茶多酚和脂溶性茶多酚在油/水界面分配系数的实验证明,乳化剂能显著增加水溶性抗氧化剂在油相中的分布,降低脂溶性抗氧化剂在油相中的分布,而增加其在水相中的分布,从而为茶多酚和脂溶性茶多酚联合处理组抗氧化的协同增效作用提供了理论基础。     

油溶型茶多酚的制备及其抗氧化性能的研究

采用酰化的方法制备油溶型茶多酚。以猪油和大豆油为实验油,用活性氧法（ＡＯＭ）对粉剂茶多酚、油溶型茶多酚、叔丁基４羟基茴香醚（ＢＨＡ）＋２,６－二叔基对甲酚（ＢＨＴ）的抗氧化性能进行了比较。实验结果表明：油溶型茶多酚的抗氧化效果优于粉剂茶多酚和ＢＨＡ＋ＢＨＴ,它对猪油、大豆油抗氧化效力分别为ＢＨＡ＋ＢＨＴ的２倍和１．５倍。     

壳聚糖W/O型乳状液的超声辅助制备及其稳定性

以非牛顿假塑性大分子壳聚糖溶液为水相,棕榈油为油相,Span-80为乳化剂,采用单因素试验及响应面试验优化超声协助制备W/O型乳液工艺,并考察优化条件下制备的乳液稳定性.结果表明:内水相含量是影响乳液粒度大小的关键因素,且超声功率对乳液的粒度及其分布存在过处理现象.优化工艺为超声功率300 W、超声时间15 min、内...     

Effect of Soybean Lecithin on Iron‐Catalyzed or Chlorophyll‐Photosensitized Oxidation of Canola Oil Emulsion

The effect of soybean lecithin addition on the iron‐catalyzed or chlorophyll‐photosensitized oxidation of emulsions consisting of purified canola oil and water (1:1, w/w) was studied based on headspace oxygen consumption using gas chromatography and hydroperoxide production using the ferric thiocyanate method. Addition levels of iron sulfate, chlorophyll, and soybean lecithin were 5, 4, and 350 mg/kg, respectively. Phospholipids (PLs) during oxidation of the emulsions were monitored by high performance liquid chromatography. Addition of soybean lecithin to the emulsions significantly reduced and decelerated iron‐catalyzed oil oxidation by lowering headspace oxygen consumption and hydroperoxide production. However, soybean lecithin had no significant antioxidant effect on chlorophyll‐photosensitized oxidation of the emulsions. PLs in soybean lecithin added to the emulsions were degraded during both oxidation processes, although there was little change in PL composition. Among PLs in soybean lecithin, phosphatidylethanolamine and phosphatidylinositol were degraded the fastest in the iron‐catalyzed and the chlorophyll‐photosensitized oxidation, respectively. The results suggest that addition of soybean lecithin as an emulsifier can also improve the oxidative stability of oil in an emulsion.     

响应曲面法优化夏秋茶中茶多酚与茶氨酸的提取工艺

以夏秋茶为原料,利用热水浸提同时提取茶多酚与茶氨酸,并利用响应曲面法进行试验设计及工艺参数优化。结果表明:热水提取夏秋茶中茶多酚的最佳工艺条件为提取温度96.12℃、提取时间40.32min、液料比15.91:1(mL/g);热水提取茶氨酸的最佳工艺条件为提取温度98.55℃、提取时间40.97min、液料比12.61:1(mL/g);提取物抗氧化活性(IC50值)最强的工艺条件为提取温度96.34℃、提取时间40.27min、液料比16.09:1(mL/g)。在96℃、40min和16:1(mL/g)的提取条件下,茶多酚与茶氨酸的产率分别是其最优提取条件下产率的99.99%和96.68%。该方法准确、可靠,可用于夏秋茶中茶多酚和茶氨酸的同时提取。     

奶茶粉末油脂乳化液性能分析

近年来,随着奶茶行业的兴起,现制现售饮品行业对粉末油脂原料的需求日趋增多,粉末油脂的乳液性能已是在奶茶中应用的重要影响因素之一。因此,以市售典型奶茶专用粉末油脂（non-dairy creamer,NDC）为研究对象,采用粒径分析与微观结构观察探究粉末油脂的乳化性,并利用Turbiscan分析仪进一步探讨其乳液稳定性。结果表明：NDC-1、NDC-2具有更小的粒径（分别为0.261 μm和0.229 μm）,乳液滴分布均匀,且在60 ℃下呈现较好的乳液稳定性（NDC-1乳液放置24 h后的稳定性指数（TSI24 h）为1.05）。在此基础上,以粉末油脂为原料制作奶茶,发现NDC-1与NDC-2奶茶组织状态更佳、口感顺滑,这为粉末油脂在奶茶领域中的应用提供了理论依据。     

茶多酚@沸石咪唑酯骨架材料/壳聚糖/海藻酸钠活性包装膜的制备及表征

本实验以海藻酸钠（sodium alginate,SA）和壳聚糖（chitosan,CS）为成膜基材,并以不同添加量（分别为0%（质量分数,后同）、1%、2.5%、5%）茶多酚（tea polyphenols,TP）@沸石咪唑酯骨架材料（zeolitic imidazolate framework-8,ZIF-8）纳米复合材料为功能性成分,通过层层组装的方式制备TP@ZIF-8/CS/SA复合膜。利用场发射扫描电子显微镜、热重分析仪、差示扫描量热仪、傅里叶红外光谱仪、质构仪、色差仪等对复合膜的形貌、组成进行表征。结果表明,TP@ZIF-8纳米复合材料添加量为5%时改变了CS/SA复合膜的颜色,并且影响了复合膜的微观形态,还增强了复合膜的热稳定性、阻隔性能和机械性能。此外,TP@ZIF-8纳米复合材料的加入使该复合膜表现出良好的抗氧化和抑菌效果。综上,本实验制备出一种具有抗菌和抗氧化的生物可降解活性包装膜,该活性包装膜在食品保鲜领域具有良好的应用前景。     

高乳化稳定性小米淀粉Pickering乳液的制备

淀粉基Pickering乳液在食品、医药、化妆品等领域的研究日益广泛。为获得高乳化稳定性淀粉基Pickering乳液,作者采用超声辅助辛烯基琥珀酸化、球磨处理改性小米淀粉,通过测定取代度、水解度、特征官能团、结晶结构、微观形貌、粒径及乳化指数等指标,研究了小米淀粉乳化能力及影响其稳定性的因素。结果表明,超声处理提高了小米淀粉酯化反应效率和取代度,OSA基团主要接枝在小米淀粉无定形区,少量进入了结晶区;球磨破坏了OSA小米淀粉的颗粒形态和晶体结构;随着球磨时间和OSA小米淀粉添加量的增加,OSA小米淀粉形成Pickering乳液的能力和乳化稳定性显著增加。超声辅助辛烯基琥珀酸化结合球磨处理是一种制备高乳化稳定性淀粉基Pickering乳液的有效方法,有助于拓展淀粉资源在Pickering乳液领域的开发利用。     

茶多酚纳米脂质体悬浮液的制备与性质研究

用乙醇注入法制备了茶多酚纳米脂质体悬浮液,考察了超声与高压均质2种后处理方式对脂质体包封率与粒径的影响。结果发现:2种后处理方式对包封率的影响差别不大,但经高压均质处理制备得到的脂质体粒径较小。对乙醇注入-高压均质后处理制备的茶多酚纳米脂质体悬浮液的性质研究表明:其平均粒径为91.4nm,多分散指数为0.114;在pH 7.0、离子强度为0.05 mol/L的磷酸盐缓冲液(PBS)中的释放动力学特性基本符合一级动力学模型;随着贮藏时间的延长或贮藏温度的升高,体系的稳定性下降。     

Evaluation of Antioxidant or Prooxidant Properties of Selected Amino Acids Using In Vitro Assays and in Oil‐in‐Water Emulsions Under Riboflavin Sensitization

The antioxidant properties of selected amino acids were tested using in vitro assays and oil‐in‐water (O/W) emulsions under riboflavin (RF) photosensitization. Headspace oxygen content, lipid hydroperoxides, and conjugated dienes were determined for the degree of oxidation. Riboflavin photosensitization was adapted as the oxidation driving force. In vitro assays showed that cysteine had the highest antioxidant properties followed by tryptophan and tyrosine. However, in O/W emulsions under RF photosensitization, tyrosine inhibited lipid oxidation whereas tryptophan acted as a prooxidant. Tryptophan accelerated the rates of oxidation in O/W emulsion without RF. The antioxidant properties of amino acids differed depending on the antioxidant determination methods, oxidation driving forces, and food matrices.