Preparation and Characterization of Human Milk Fat Substitutes Based on Triacylglycerol Profiles

Human milk fat substitutes (HMFS) having similarity in (TAG) composition to human milk fat (HMF) were prepared by Lipozyme RM IM‐catalyzed interesterification of lard blending with selected oils in a packed bed reactor. Four oil blends with high similarity in fatty acid profiles to HMF were first obtained based on the blending model and then the blending ratios were screened based on TAG composition similarity by enzymatic interesterification in a batch reactor. The optimal ratio was determined as lard:sunflower oil:canola oil:palm kernel oil:palm oil:algal oil:microbial oil = 1.00:0.10:0.50:0.13:0.12:0.02:0.02. This blending ratio was used for a packed bed reactor and the conditions were then optimized as residence time, 1.5 h; reaction temperature, 50 °C. Under these conditions, the obtained product showed high degrees of similarity in fatty acid profile with 39.2 % palmitic acid at the sn‐2 position, 0.5 % arachidonic acid (n‐6) and 0.3 % docosahexaenoic acid (n‐3) and the scores for the degree of similarity in TAG composition was increased from 58.4 (the oil blend) to 72.3 (the final product). The packed bed reactor could be operated for 7 days without significant decrease in activity. The final product presented similar melting and crystallization profiles to those of HMF. However, due to the loss of tocopherols during deacidification process, the oxidative stability was lower than that of the oil blend. This process for the preparation of HMFS from lard with high similarity in TAG composition by physical blending and enzymatic interesterification, as optimized by mathematical models in a packed bed reactor, has a great potential for industrialization.     

Preparation of Human Milk Fat Substitutes from Lard by Lipase‐Catalyzed Interesterification Based on Triacylglycerol profiles

Human milk fat substitutes (HMFSs) with triacylglycerol profiles highly similar to those of human milk fat (HMF) were prepared from lard by physical blending followed by enzymatic interesterification. Based on the fatty acid profiles of HMF, different vegetable and single‐cell oils were selected and added to the lard. Blend ratios were calculated based on established physical blending models. The blended oils were then enzymatically interesterified using a 1,3‐regiospecific lipase, Lipozyme RM IM (RML from Rhizomucor miehei immobilized on Duolite ES562; Novozymes A/S, Bagsværd, Denmark), to approximate HMF triacylglycerol (TAG) profiles, particularly with respect to the distribution of palmitic acid in the sn?2 position. The optimized blending ratios were determined to be: lard:sunflower oil:canola oil:palm kernel oil:palm oil:algal oil:microbial oil = 1.00:0.10:0.50:0.13:0.12:0.02:0.02. The optimized reaction conditions were determined to be: enzyme load of 11 wt%, temperature of 60 °C, water content of 3.5 wt%, and reaction time of 3 hours. The resulting product was evaluated for total and sn?2 fatty acids, polyunsaturated fatty acids, and TAG composition. A high degree of similarity was obtained, indicating the great potential of the product as a fat alternative for use in infant formulas.     

Application of the factorial design of experiments to biodiesel production from lard

Synthesis of biodiesel from lard was carried out using potassium hydroxide as a catalyst. A 3² factorial design of experiments was used. The effects of agitation speed and catalyst concentration were studied. A regression model was obtained to predict the methyl ester concentration and adequately describe the experimental range studied.     

人乳脂替代品以及酶使用寿命的研究

人乳脂具有独特的结构，棕榈酸主要分布在sn-2位，猪油的sn-2位有与其相似的结构。采用具有sn-1,3催化专一性的Lipozyme IM作催化剂，进行酯交换改性猪油来制备人乳替代品。应用响应面法设计优化实验。其最优条件为：水分含量3.7%(以酶量计）；反应温度61℃；底物比脂肪酸：猪油2.4:1(mol比）；酶量10％（以底物质量计），反应时间1h。该条件下酶可以重复使用39h，得到结构符合人乳脂的替代品。     

蜂胶在食用油脂中的抗氧化作用

本文以猪油、菜油为实验材料,测定其POV值来评价蜂胶在动物油和植物油中的抗氧化特性,并与没食子酸丙酯(PG)比较.结果表明蜂胶能够延缓这些底物的氧化进程,明显延长诱导期.且柠檬酸、卵磷脂能增强其抗氧化功能.蜂胶的抗氧化能力强于相近浓度的PG,蜂胶在短时间高温加热后,其抗氧化效率不受影响.     

猪油酯交换产物性质测定与分析

本实验对酯交换前后样品进行SFI和DSC测定分析,确定了本实验进行的酯交换过程是脂肪酸排布随机化的过程,并且随机化后产品物理性质得到改良,更适合用作起酥油。     

Composition and thermal analysis of ternary mixtures of avocado fat:palm stearin:cocoa butter (Avo:PS:CB)

Avocado fat is a semi-solid substance with potential functional lipid characteristics. A study was carried out to evaluate the effect of addition of palm stearin and cocoa butter on the solidification behavior of avocado fat to formulate a mixture to become similar to lard. A total of three mixtures were prepared: avocado fat:palm stearin:cocoa butter (88:7:5), avocado fat:palm stearin:cocoa butter (86:7:7), avocado fat:palm stearin:cocoa butter (84:7:9; w/w), and identified by the mass ratio of avocado fat to palm stearin and cocoa butter. The fat mixtures were compared with lard in terms of the fatty acid and triacylglycerol compositions using gas chromatography and high-performance liquid chromatography, thermal properties using differential scanning calorimetry and solid fat content using p-nuclear magnetic resonance. Although there were considerable differences between lard and the fat mixtures with regard to fatty acid and triacylglycerol compositions, some similarities were seen with regard to thermal properties and solid fat content profile. Of all the fat mixtures, avocado fat:palm stearin:cocoa butter (84:7:9) displayed closer similarity to lard with respect to thermal transitions at –3.59°C and its solid fat content profile showed the least difference to that of lard throughout the temperature range measured.     

The removal of food fat based soils during the washing of fabrics

The removal of a deposition mass of 8.55 ± 0.43 mg cm⁻² of lard from plain-weave cotton fabrics under controlled flow conditions has been investigated using water and a solution containing a non-ionic surfactant. Three distinct flow regimes of cross-flow, through-flow and a 2:1 combination of cross- and through-flow respectively have been studied at three cleaning agent temperatures of 10 °C, 25 °C and 40 °C. The lard removal efficiency has been quantified using weighing and image analysis methods to determine the mass per unit area of lard in the treated region. The hydrodynamic resistance changes of the fouled samples have been monitored during the washing process.     

A Comparison of the Thermo-Physical Behavior of Engkabang (Shorea macrophylla) Seed Fat–Canola Oil Blends and Lard

A study was carried out to compare the thermo-physical behaviors of canola–Engkabang fat blends with those of lard (LD). Four blends were prepared by mixing canola oil with Engkabang fat (CaO/EF) in different ratios: EF-1, 75:25; EF-2, 70:30; EF-3, 65:35; EF-4, 60:40. The fat blends and LD were compared in terms of their basic physicochemical parameters, fatty acid and triacylglycerol (TAG) compositions, melting, solidification, hardness, and polymorphic properties. The slip melting points (SMP) of the fat blends were found to range from 24.8 to 31.2 °C; EF-2 was found to display an SMP value closer to that of LD. With respect to the melting curve of CaO, the melting curves of all fat blends were found to display an additional high-melting thermal transition in the temperature region above 10 °C. The peak maximum of the high-melting thermal transition of EF-3 was the closest to that of LD. The solid fat content (SFC) value of EF-3 was equal to that of LD at 25 °C, whereas the SFC values of EF-2 and LD were similar at 30 to 40 °C. According to textural analysis, EF-2 was found to display a hardness value somewhat closer to that of LD. X-ray diffraction analysis showed that LD and fat blends EF-1, EF-2, and EF-3 display β polymorphic forms.