Characterization and Oxidative Stability of Structured Lipids: Infant Milk Fat Analog

Structured lipids (SLs) for infant milk formulation were produced by enzymatic interesterification of tripalmitin with vegetable oil blends and fish oil. The SLs were characterized by fatty acid content and structure, melting profiles, oxidative stability index, free fatty acid (FFA) concentration, and tocopherol content. Oxidative stability was studied using accelerated methods by quantifying FFA, peroxides (peroxide value) and aldehydes (p-anisidine value) production. Total oxidation (TOTOX value) was calculated as 2 × (peroxide value) + (p-anisidine value). The structured lipids after purification by distillation and addition of antioxidants had melting profiles, oxidative stability index, and initial FFA concentration that were similar to that of the starting oil blends, while the fatty acid composition and structure of the SLs were similar to that of human milk fat. Oxidative stability of the SLs was improved with tocopherol addition as antioxidants and was comparable to that of the vegetable oils and oil blends.     

Improving the Oxidative Stability of Krill Oil-in-Water Emulsions

A positively charged protein (fish gelatin) or a negatively charged protein species (heat-treated milk protein–carbohydrate mixture) was added to a primary krill oil (KO) emulsion stabilized by the phospholipids inherent in KO, with the aim of improving the oxidative stability of KO-in-water emulsions at pH 8.0 (10 % KO). The positively charged fish gelatin deposited on the primary interface of the oil droplets in the primary KO-in-water emulsion improved the oxidative stability of the KO-in-water emulsion as evidenced by the higher eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) remaining and lower propanal produced after accelerated oxidation (40 °C, 25 days). The addition of the negatively charged heat-treated milk protein–carbohydrate mixture containing Maillard reaction products (MRP) to the bulk phase of the emulsion also enhanced the oxidative stability of the KO-in-water emulsion. The addition of MRP to the aqueous phase of phospholipids stabilized emulsion droplets offered more protection to EPA and DHA of the KO emulsions compared to the formation of an additional layer at the interface of the KO emulsion droplet. This suggests that interventions based on addition of antioxidant species to the formulation were more effective for arresting oxidation than increasing the thickness of the droplet interface. The addition of proteins into KO containing emulsion formulations is a promising strategy for protecting omega-3 marine phospholipids against oxidation.     

稠油O/W型乳状液稳定性的研究

以大庆黑帝庙稠油为研究对象，依据稠油乳化降粘原理及O／W型乳状液的形成机制，考察了表面活性剂类型及添加量，碱的添加量，温度、油／水比、振荡方式等因素对稠油O／W型乳状液稳定性的影响。为筛选降粘剂复合配方及选择降低粘工艺提供了必要的基础数据。     

乳化炸药储存稳定性研究

采用扫描电镜技术ＳＥＭ跟踪乳化炸药在储存中的实际变化以期了解这种变化与其内在结构的本质联系,从而探索出提高乳化炸药储存稳定性的新途径。     

乳化液膜稳定性研究

以煤油为膜溶剂，采用PNS-89414等表面活性剂，按液膜提取方法，研究了各种因素对多重乳状液稳定性的影响，如乳化剂、渗透压、粘度、内相试剂的浓度和搅拌工艺等。结果表明，它们对多重乳状液稳定性都有不同程度的影响。     

正交试验用于乳状液稳定性能研究

通过正交试验研究复合表面活性剂乳状液稳定性,得出了所研究范围内复合表面活性剂的稳定性方程,并通过MATLAB数学软件求出其最优配方为OP-10为1%,十二烷基硫酸钠0.2%,椰油酰胺基丙基甜菜碱（CAB-35）0.2%,异丙醇0.02%,最后通过实验论证该体系为最优配方。     

Colloidal Characteristics,Drug Encapsulation,and Oil-in-Water Emulsion of Dodecenyl-Modified Alginate

Sodium alginate was hydrophobically modified with dodecenyl succinic anhydride in a neutral aqueous solution (pH = 6.8) at room temperature, forming an environmentally friendly amphiphile dodecenyl-modified alginate (DMA). Surface activity of DMA was assessed using surface tension and zeta-potential measurements. Hydrophobic compound-loading capacity as well as oil-in-water emulsion stability of DMA solutions were investigated to study the potential applications of DMA. The critical micelle concentration (CMC) of DMA aqueous solution was found to be 0.70 mg mL⁻¹ with the surface tension being around 33.0 mN m⁻¹. DMA solutions were able to solubilize hydrophobic compounds like Sudan IV and Clofazimine in aqueous medium. 10% peanut oil-in-water emulsions stabilized by 10 mg mL⁻¹ DMA presented good stability during 7 days of storage and the interfacial tension between water and oil was lowered from 23.0 to 9.0 mN m⁻¹. Results showed that DMA was an efficient surfactant and could work as a drug-delivery vehicle or a natural food emulsion stabilizer in the future.     

全丙乳液的合成及乳胶漆的制备

以甲基丙烯酸甲酯,丙烯酸丁酯为单体,用自制的乳化剂合成了全内乳液。配制了性能良好的乳胶漆,讨论了ＰＶＣ等因素对乳胶漆性能的影响。     

ZB——机用书画装裱粘合剂的研制

采用VAC/BA/AAm三元共聚体系制备乳液型书画装裱粘合剂。对PVA用量、聚合反应温度、引发 剂、pH值、AAm用量等对粘合剂性能的影响进行了研究,确定了最优制备条件。     

司盘—80质量指标与乳化液稳定性关系的研究

介绍了司盘－８０有关指标与乳化液稳定性的关系,实验结果表明,在一定范围内增加酯化物含量,放 范围,降低水分含量有利于乳化液稳定性的提高,由不同质量油酸生产的司盘－８０的酸值,对乳化液稳定性的影响不具有可比性。     

表面活性剂和乳液稳定性研究进展

表面活性剂和乳液稳定性最新研究中出现的研究网络化和理论纵深化特点说明了目前整个科学领域中广泛存在着深层交叉的表面活性剂及乳液稳定性研究中的具体表现。在表面活性剂和乳液应用研究中,指出了具有优良生物环保特性和其他功能性的新型表面活性剂研究开发和与药剂配制相关的表面活性剂和乳液体系的应用是当前的热点问题。     

聚丙烯酸酯乳液生产工艺研究

聚丙烯酸酯外用乳胶漆其优良的性能主要决定于丙稀酸脂聚合乳液的性能。从聚丙稀酸脂单体、聚丙烯酸酯的乳化聚合、配方及助剂等方面对生产操作及工艺研究进行了探讨,以获得质量更佳的乳液,确保漆膜的优良特性。     

Oxidative Stability and Sensory Attributes of Fermented Milk Product Fortified with Fish Oil and Marine Phospholipids

Marine phospholipids (PL) are potential ingredients for food fortification due to its numerous advantages. The main objective of this study was to investigate whether a fermented milk product fortified with a mixture of marine PL and fish oil had better oxidative stability than a fermented milk product fortified with fish oil alone. Fortification of a fermented milk product with marine PL was performed by incorporating 1 % w/w lipids, either in the form of neat oil or in the form of a pre-emulsion. Lipid oxidation was investigated in the neat emulsions and fortified products by the measurements of primary, secondary volatile oxidation products and tocopherol content upon 32 days storage at 2 °C and 28 days storage at 5 °C, respectively. Analyses of particle size distribution, viscosity and microbial growth were also performed. In addition, sensory attributes such as sour, fishy and rancid flavor/odor were evaluated in fortified products by a trained panel. The results obtained showed that incorporation of a mixture of marine PL and fish oil into fermented milk products decreased the oxidative stability and sensory quality of fortified products. The pH-dependent behavior of iron seemed to be the main factor that influenced the lipid oxidation in the marine PL emulsion and fermented milk system. In addition, both oxidative stability and sensory acceptability of fortified products varied depending on the quality of the marine PL used for fortification.     

Enzymatic Synthesis of Tyrosol-Based Phenolipids: Characterization and Effect of Alkyl Chain Unsaturation on the Antioxidant Activities in Bulk Oil and Oil-in-Water Emulsion

Oxidative stability of lipids is one of the most important parameters affecting their quality. Lipase‐catalyzed lipophilic tyrosyl esters with an equivalent carbon alkyl chain but different degrees of unsaturation (C18:0 to C18:4n3) were prepared, characterized, and used as antioxidants. Free fatty acids and fatty acid ethyl esters (substrate molar ratio tyrosol: acyl donor, 1:10) were used as acyl donors and immobilized lipase from Candida antarctica was the biocatalyst (10 %). The phenolipids were isolated and characterized using ESI–MS, ¹H‐NMR, and ¹³C‐NMR. Peroxide value (PV) and para‐anisidine value (p‐AV) were measured to evaluate their antioxidant activities in bulk oil structured lipid (SL) and in an oil‐in‐water emulsion (SL‐based infant formula). No significant difference was found in yield and reaction time between the two types of acyl donors. However, as the unsaturation of the fatty acids increased the reaction time also increased. In SL, tyrosyl esters exhibited lower antioxidant activity than tyrosol whereas the addition of an alkyl chain enhanced the antioxidant efficiency of tyrosol in infant formula. Tyrosyl oleate was the most efficient antioxidant in the emulsion system followed by tyrosyl stearate and tyrosyl linoleate. These results suggest that the synthesized phenolipids may be used as potential antioxidants in lipid‐based products.     

Oxidation and Colloidal Stability of Oil-in-Water Emulsion as Affected by Pigmented Rice Hull Extracts

Extracts from the hull of pigmented rice were prepared using a mixture of methanol–water (1:1, 2:1, and 3:1, v/v) for different extraction times (0–180 min). Total phenolic content (TPC) of the extracts increased with increasing concentration of methanol and extraction time (P < 0.05). A positive correlation between TPC and antioxidant activities, i.e., DPPH and ABTS radical scavenging activities and reducing power, was observed. The extracts prepared using methanol–water at the ratio of 3:1 for 180 min at 50 °C, referred as rice hull phenolic extract (RHPE), showed the highest TPC and free radical scavenging abilities and reducing power (P < 0.05). When the effects of RHPE on physicochemical stability of the emulsions stabilized by different emulsifiers, i.e., Tween 20 and bovine serum albumin (BSA), were examined, the collapse of emulsion was retarded when RHPE was applied in BSA‐based emulsions, whereas a negative effect was noticeable in Tween 20‐based counterpart. Lower oxidative degree was found for BSA stabilized emulsions, compared to Tween 20 containing system. RHPE (1–3 %) markedly improved the oxidative stability, particularly for BSA stabilized emulsions. Therefore, RHPE could be employed along with the selected protein to increase physicochemical stability of emulsion.     

The Role of Oil Phase in the Stability and Physicochemical Properties of Oil-in-Water Emulsions in the Presence of Gum Tragacanth

Different emulsions based on six types of vegetable oils (sunflower, canola, sesame, olive, coconut, and palm olein) were studied to investigate the role of the oil phase in the stability and physicochemical characteristics of oil-in-water emulsions prepared with gum tragacanth. The results indicated that the stability, rheological parameters, and size distribution of emulsions were dependent on the oil type. Based on the interfacial tension value, the type of oil did not have a significant effect on the gum tragacanth-emulsifying properties. The formulation based on sunflower and coconut oil led to producing more stable emulsion and a sample containing palm olein resulted in an unstable emulsion. Rheological analysis revealed that the sample based on palm olein showed the lowest consistency coefficient (2.10 ± 0.05 Pas ⁿ), elastic modulus (3.90 ± 0.21 Pa), and energy of cohesion (80.87 ± 1.1 J m⁻³). This study revealed that using oils with lower viscosity and higher density led to the higher stability of the emulsion samples.     

Oxidative Stability of Conventional and High-Oleic Vegetable Oils with Added Antioxidants

The oxidative stability of conventional and high-oleic varieties of commercial vegetable oils, with and without added antioxidants, was evaluated using the oil stability index (OSI). Oil varieties studied were soybean (SOY), partially-hydrogenated soybean (PHSOY), corn (CORN), sunflower (SUN), canola (CAN), high-oleic canola (HOCAN), very high-oleic canola (VHOCAN), oleic safflower (SAF) and high-oleic sunflower (HOSUN). One or more commercial antioxidants were added to the four most stable oils at supplier-recommended levels: rosemary extract (RM; 1,000 ppm), ascorbyl palmitate (AP; 1,000 ppm), tert-butylhydroquinone (TBHQ; 200 ppm), and mixed tocopherols (TOC; 200 ppm). OSI in hours (h) at 110 °C of the conventional oils were 5.2, 7.6, 8.4, 9.8, 10.9 and 14.3 h for SUN, SOY, CAN, CORN, PHSOY and SAF, respectively. OSI of high-oleic variants were 12.9, 16.5 and 18.5 h for HOCAN, HOSUN and VHOCAN, respectively. Maximum OSI values for the four most stable oils when treated with antioxidants, were 40.9, 48.5, 48.8 and 55.7 h for HOCAN, VHOCAN, SAF and HOSUN, respectively. Addition of TBHQ, alone and in combination with other antioxidants, resulted in the greatest increase in oxidative stability of SAF and other high-oleic oils evaluated. AP had a positive synergistic effect when used with TBHQ, while RM decreased TBHQ effectiveness.     

丙烯酸氟烷基酯乳液聚合的研究

以甲基丙烯酸氟烷基酯(ZonylTM)、甲基丙烯酸甲酯、丙烯酸正丁酯为原料,采用氧化-还原引发体系,以十二烷基硫酸钠和全氟辛酸铵(1:1)为乳化剂,经超声波预乳化后进行聚合,成功制备了一系列高氟单体含量的三元共聚物乳液,系统研究了聚合条件对乳液稳定性和反应动力学的影响,测得聚合反应的表观活化能Ea为68.4kJ/mol。考察了氟元素含量对共聚物表面性能的影响,含氟共聚物对水和对油的接触角最高可分别为116°和77.5°。     

氧化还原引发丙烯酸正丁酯乳液聚合

选用过氧化氢二异丙苯-硫酸亚铁氧化还原体系引发丙烯酸正丁酯的乳液聚合,研究了单体进料时间和反应温度对聚合反应速度、乳胶粒子尺寸和分子量的影响。结果表明,固定聚合条件,单体加料时间延长至3h时,粒径由90 nm减小至65nm,分子量降低了38%;当反应温度由20℃升高至70℃时,粒子粒径由95nm减小至65nm,表观聚合反应活化能为29.80kJ/mol。