Emulsifying properties of phospholipids in the reconstitution of cream using butter oil

Phospholipids (PL) extracted from bovine milk and soybeans were tested for their emulsifying properties in reconstituted cream using butter oil. Bovine milk PL dispersed in the oil phase were found to stabilize the cream, whereas soybean PL were found to solidify the cream. Differential scanning calorimetry was carried out on the two creams, revealing that the addition of soybean PL to the butter oil retarded the onset of crystallization during cooling, which consequently led to a lower solid fat content within the fat globules. It was suggested that the difference in the crystallization behavior of butter oil due to the addition of different PL led to the different emulsion stabilities of the reconstituted creams.     

Phospholipid class and FA compositions of modified soybeans processed with two extraction methods

Soybean lecithin is used as an emulsifier in food, cosmetic, and pharmaceutical industries. The proportion of individual phospholipids (PL) and their FA composition may affect the functional properties of lecithin. In this research, lecithins recovered from four modified soybeans and one commodity soybean, which were processed by extrusion-expelling and conventional solvent extraction, were analyzed for proportion of PL class and FA composition. HPLC with an ELSD analysis demonstrated that the percentage of PC in extrusion-expelled lecithin was higher than in solvent-extracted lecithin, whereas the PE content was lower. GC analysis showed that FA compositions of the PL varied with soybean type. The oil extraction method did not significantly affect FA composition. Critical micelle concentration tested with a tensiometer showed differences among the lecithins.     

天然油脂一步法烷氧基化及其产物乳化性能研究

以几种天然油脂(豆油、菜油、棕榈油、橄榄油)为原料,在自制FY系列催化剂作用下与环氧乙烷(EO)或环氧丙烷(PO)在140℃、0 3～0 4MPa下,经一步法嵌入反应得到乙氧基化油脂(EFO)或丙氧基化油脂(PFO)。测定了EFO和PFO的自乳化性能和乳化性能,并实验了大豆色拉油衍生EFO代替大豆色拉油作为原料复配润滑油剂及该油剂形成微乳状液的能力。实验结果表明,在油脂分子结构中嵌入EO或PO后,产物EFO及PFO的自乳化性能及乳化性能均得到提高。在该实验范围内,EFO的自乳化力最高可达原油脂的36倍,乳化力则提升140倍以上。含大豆色拉油衍生EFO的油剂与含大豆色拉油的油剂相比,油剂含油率高;在与水互溶时,前者具有更宽的微乳区域,且微乳液稳定性好;其中优选出的油剂配方可与水以任意比例混合均形成微乳状液。     

Effects of Chain Length of Saturated Fatty Acids on Plasma Total,LDL- and HDL-Cholesterol Levels

We conducted two clinical studies to examine the effects of diets high in stearic acid and lauric + myristic acid on plasma lipids and lipoproteins of healthy young men. In the first study subjects (n = 15) were fed whole food diets high in cocoa butter, butter, olive oil and soybean oil. In the second study, subjects were fed diets very high in saturated fatty acids (> 20% of calories) that were high in either stearic acid (from cocoa butter or milk chocolate) or lauric + myristic acid (from butter). In the first study, cocoa butter elicited a neutral cholesterolemic effect, whereas the butter diet was hypercholesterolemic and the olive oil and soybean oil diets were hypocholesterolemic. In the second study, the diets high in stearic acid did not raise plasma total and LDL-cholesterol levels, whereas, as in the first study, butter was markedly hypercholesterolemic. Regression analyses performed on the individual data from these two clinical studies were conducted to establish the cholesterolemic effects of individual fatty acids. The bestfitting linear regression equations relating ΔTC (change in plasma total cholesterol) was: ΔTC = 2.3 ΔC_14:0 + 3.0 ΔC_16:0-0.8 ΔC_18:0-1.0 ΔPUFA, where Δ fatty acid = change in intake expressed as percent of calories. This predictive equation separates stearic acid from the other long-chain saturated fatty acids and suggests that it has an independent cholesterol-lowering effect. In conclusion, stearic acid is a unique long-chain saturated fatty acid.     

The function of phospholipids of soybean lecithin in emulsions

A number of commercially available soybean lecithins were analyzed with respect to their phospholipid composition and emulsifying properties. A phosphatidylcholine (PC) from soybean swells to a lamellar liquid crystalline phase which incorporates slightly less than 50% of water. The swelling behavior of the commercially available soybean lecithins may be different depending on the concentration of other phospholipids such as phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidic acid (PA). In the presence of the negatively charged phospholipids PI and PA, the swelling of the lamellar phase of PC was dramatically enhanced while a lecithin with equal amounts of PC and PE and small quantities of PI and PA formed two liquid crystalline phases, i.e., a lamellar and a hexagonal phase. Stable o/w-emulsions can be prepared when the phospholipid composition is such that a lamellar liquid crystalline phase in equilibrium with the oil and water phases incorporates large amounts of water. The minimal amount of emulsifier required to stabilize the emulsions has been estimated to give an interfacial film of ca. 80 Å thickness which corresponds to a thickness of two double lipid layers in the interfacial film. The incorporation of large amounts of water is obtained if the lamellar layers contain dissociated ionic groups.     

Effect of degumming reagents on the composition and emulsifying properties of canola,soybean and sunflower acetone insolubles

Acetone insolubles (AI) extracted from crude canola, soybean and sunflower oils using six degumming reagents (water, citric, phosphoric and oxalic acids plus acetic and maleic anhydride) were separated into phospholipid (PL) components by HPTLC. The separated PL were quantified by phosphorus determination. Statistical analysis of the PL composition data indicated that the chemical degumming reagents did not dramatically alter the PL profiles although some significant differences were observed. Acetone insolubles recovered by water degumming produced the most stable oil-in-water emulsions. Those AI isolated by citric acid, acetic anhydride and maleic anhydride treatments produced slightly less stable emulsions but showed good potential as emulsifying agents. Phosphoric and oxalic acid treatments produced AI with very poor emulsifying properties.     

Möglichkeiten zur Steuerung der Milchqualität mit Raps in unterschiedlicher Form im Hinblick auf Verarbeitungseigenschaften,insbesondere zu Butter

Possibilities to Influence Milk Quality with Rape in Different Shape with Regard to Technical Properties, Especially for Butter In spite of application of most developed technology in the creamery there are still appearing problems with the spreadability of winter butter during the last years. Reasons are increased milk fat contents, larger amounts of milk out of roughage for cost degression purposes and missing amounts of fat of oil seeds, which were present as rest fat after earlier applied pressing processes. For this situation a concept was developed, which foresees the measurement of fat consistency of herd milks. A quick test with a penetrometer is applied. The importance of different roughages, especially maize silage and quality of grass silage was determined. The possibility to steer fat consistency by means of oil seeds was proved. Here is a report of a practical trial together with feed mills and a dairy. The supply of roughly grinded 00-rape seed, rape cake with a rest fat content of 10% and rape-calcium-salts with the mixed feed improved milk fat consistency so far, that resistance to cutting and spreadability of butter were clearly improved, resp. Effects on cheese processing properties were not observed, quality of whipped cream was equal to such made of summer cream. It was slightly unfavourable versus such made of hard winter cream.     

Phospholipids plus tocopherols increase soybean oil stability

The phospholipids (PL), phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were purified from commercial soybean lecithin by silicic acid chromatography and preparative silica gel thin layer chromatography (TLC). Purified phosphatidylinositol (PI) was obtained commercially. Phosphatidic acid (PA) was made from PC by phospholipase D action and purified by preparative TLC. Commercial soybean tocopherols (TOC) were further purified in a florisil column. Combinations of PL and TOC were added to commercially refined, unhydrogenated soybean oil to determine the effects and interaction of PL and TOC on soybean-oil stability. Oil stability was determined by measuring the time in days of oil samples incubated at 110C to reach a peroxide value of 100 meq/kg. Additions of TOC and all PL except PA increased the stability of the oil. PI and PE appear to be more effective than PC in increasing oil stability. The effect of the PL was not simply a matter of pro-oxidant metal inactivation, but rather appeared to extend the effectiveness of the TOC in free-radical termination.     

Enzyme-Assisted Aqueous Extraction of Oil from Isolated Oleosomes of Soybean Flour

Enzyme-assisted aqueous extraction of oil from isolated soybean oleosomes was evaluated as an alternative to the conventional organic solvent extraction. Three different processes: hydrolysis of oleosomes, thermal demulsification of the skim or the slurry, and destabilization of the cream by the churning butter process were examined to enhance the release of free oil from isolated oleosomes. The oil extraction involved incubating the oleosomes with either 0, 2.5 or 5% protease (Protex 6L^®) at 60 °C, pH 9 for 18 h, destabilizing the slurry by three thermal strategies: freeze/thaw, freeze/thaw and heating, and destabilizing the cream by the churning butter process without and with 5% of phospholipase A₂ (Multifect L1 10L^®), at 40 °C, pH 8 for 4 h. The best total free oil yield was 83–88% by hydrolyzing oleosomes with 2.5 or 5% Protex 6L^®, destabilizing the slurries by heating and destabilizing the resulting cream by the churning butter process. The oleosomes treated with 2.5 and 5% proteases generated hydrolyzed soybean storage proteins at 18–20% degree of hydrolysis, with all the storage proteins hydrolyzed to peptides smaller than 6.5 kDa, compared to the oleosomes disrupted without proteases.     

The Effect of Phospholipids on Butter Physical and Sensory Properties

The addition of phospholipids (PL), either in the form of the milk fat globule membrane (MFGM) or soy lecithin, had a significant influence on butterfat crystal morphology. At low concentrations, PL addition increased spherulite size, but as PL levels reached 2 wt%, spherulite formation was inhibited and the microstructure consisted of well dispersed individual crystals. This change in crystal structure made the butter harder, less grainy at low temperatures, and less prone to oiling-off above room temperature. PL addition was also shown to affect the relative concentrations of the various species created during crystallization. Of the two 2L β′ species that form at crystallization onset, the presence of PL shifted the balance towards the first species at the expense of the second. PL also facilitated the polymorphic transition of the 3L α species to a 2L β′ structure. It is unclear, however, whether the inhibition of spherulite formation was due directly to the inhibition of secondary nucleation by PL at the crystal surface, or indirectly by the reduction of supercooling resulting from a more rapid polymorphic transition. Evidently, PL concentration must be properly controlled during manufacturing in order to optimize butter functional properties.     

Fractionation of soybean phospholipids by high-performance liquid chromatography with an evaporative light-scattering detector

Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) from 23 soybean lines with a wide range of fatty acid compositions were resolved into seven fractions by high-performance liquid chromatography (HPLC). Fraction identities were assigned from fatty acid compositions determined by gas chromatography (GC). A mass detector, i.e., an evaporative light-scattering detector, was used for HPLC quantification. The detector response was a power function of PC and PE concentrations. Various correction methods were applied to the detector response to obtain the best agreement between phospholipid (PL) fatty acid compositions determined by GC and that calculated from the corrected HPLC fraction percentages. The corrected HPLC fraction composition also was compared with that calculated from stereospecific distribution data using a 1-random-2-random hypothesis. Correlation between PL-fatty acid and HPLC-fraction percentages showed that genetic modification of soybean oil composition caused changes in PL species, which alter physical properties and may alter the physiological functions of PL in biomembranes.     

The Effect of Phospholipids on Milkfat Crystallization Behavior

Depending on the production method, the fat component in butter can either be in a continuous phase or entrapped by milk fat globule membranes (MFGM). Phospholipids like those present in the MFGM are known to affect milk fat crystallization behavior. This study examines the effect of MFGM phospholipid concentration on butter crystal structure. Regular raw cream was first concentrated to 85% fat via centrifugation to produce a “plastic” cream, and was then blended with anhydrous milk fat (AMF) and skim milk in order to maintain the total fat-to-water ratio while altering the total amount of MFGM in the butter product. Whereas mixtures of AMF and skim milk contained large spherulites that had finer structures as the degree of supercooling was increased, the addition of globular fat (GF) broke up these structures, eventually producing smaller individual needle-like crystals. However, high levels of GF also lead to the coalescence of the aqueous phase, creating large water pockets that adversely affect sensory properties. Thus, the phospholipid concentration in the final butter product must be controlled in order to obtain optimal crystal structure and product quality.     

Effects of alkylamines and PC on the oxidative stability of soybean oil TAG in milk casein emulsions

The effects of alkylamines and PC on the coppercatalyzed oxidation of soybean oil TAG were studied in milk casein emulsions. Stearylamine showed an antioxidant effect in casein emulsions in the presence of PC, whereas dicetylphosphate acted as a prooxidant. The antioxidant or prooxidant effect could be explained by the electrostatic repulsion or attraction between positively charged stearylamine or negatively charged dicetylphosophate and positively charged copper ion at the interface, respectively. On the other hand, these effects were not observed in the absence of PC, suggesting the importance of PC for charged components to show their activities at the interface. Other types of alkylamines—spermine, spermidine, and putrescine—also inhibited the oxidation of soybean oil TAG emulsified with casein in the presence of PC. The antioxidant effects of these natural polyamines were higher than that of stearylamine. PC molecular species also affected soybean oil TAG oxidation in emulsion. The oxidative stability of soybean oil TAG increased in the emulsion with PC containing oleic acid.     

The nutritive value of soybean oil meal prepared by the different methods of oil extraction

This article is primarily a review of the literature pertaining to the subject. Solvent extracted, hydraulic, and expeller soybean oil meals all contain, if properly cooked, protein of high biological value, similar to that of milk protein. Solvent extracted meal has a higher percentage of protein. Since expeller and hydraulic meals contain more oil than solvent extracted soybean oil meal, they naturally have a slightly higher vitamin A and D potency, but the amounts of these vitamins contained in any type of soybean meal or even in the whole soybean are not significant. Levine’s assays reveal that solvent process soybean oil meal contains roughly 2.8 I.U. of vitamin B per gram of solids compared to 1.0 I.U. for hydraulic meal. According to results of Cornell experiments, the vitamin G content of soybeans is not materially affected by any of the common methods of processing. Kraybill reports that expeller and hydraulic pressed soybean oils contain more “lecithin” (total phospholipins) than hexane extracted soybean oil. Therefore his results indicate that our domestic solvent extracted meal contains slightly more “lecithin” than expeller meal. “Lecithin” in soybean oil meal may be valuable as an antioxidant to stabilize the vitamin A contained in mixed feeds.     

Physical Characteristics of Peanut Butter Influenced by Fully Hydrogenated Flixweed Seed Oil (Descurainia sophia L.) as a Stabilizer

The functional benefits provided by flixweed seed oil (FSO) warrant its application as an alternative to current commercial stabilizers used in peanut butter. The extracted FSO was fully hydrogenated and added to the lab‐made peanut butter in quantities of 1, 1.5, and 2 % (w/w). Samples were stored at 4, 21, and 40 °C, and tested at 2, 6, 16, and 24 weeks for oil separation tests and texture characteristics including hardness, adhesiveness, cohesiveness, and gumminess. Fully hydrogenated flixweed seed oil (FHFO) improved the oil holding capacity of peanut butter at 1, 1.5 and 2 % (w/w). Peanut butter containing FHFO, at a quantity of 2 % (w/w), showed the least oil separation and had comparable or less oil separation than the sample containing 1.5 % commercial stabilizer. Other physical properties were comparable between these two samples.     

Production of low molecular weight esters using vegetable oils or butter oil as reaction media

Corn oil, peanut oil, sunflower oil, soybean oil, canola oil, olive oil and butter oil were tested as replacements for nonaqueous solvents in the lipase mediated biosynthesis of ethyl butyrate, butyl butyrate, isoamyl butyrate and isoamyl acetate. The most effective oils tested were butter oil, soybean oil, peanut oil and olive oil (yield = 50–60% after 16 h incubation at 25°C) while corn oil was least effective (yield = 38%). Higher yields were obtained, for all ester syntheses, at a reaction temperature of 50°C. Drying agents were shown to have no effect or to inhibit the synthesis. Of the four enzymes tested, Candida cylindracea lipase was the most effective enzyme for ethyl butyrate synthesis.     

Role of actinidin in the hydrolysis of the cream milk proteins

Cream from milk is commonly used as the starting material of variety food products such as cream cheese, fat added cheeses, butter and buttermilk. The protein content of cream is only about 2% but strongly affects the quality of fat containing dairy products especially cheeses which are frequently characterized by an unsatisfactory texture. In this work, the suitability of the actinidin to function in a “fat-supplemented” environment was tested and the SDS–PAGE profile of cream treated with the enzyme was also analyzed. The results show that actinidin is able to degrade all the cream proteins to smaller than 29.0 kDa fragments suggesting a novel utilization as preparatory treatment in the production of milk derived products characterized by a reduced content of undesirable proteins.     

Formation of dispersed particles composed of soybean oil and phosphatidyl choline

The purpose of this study was to investigate the dispersal mechanism of soybean oil (SO) in phospholipids to form a fat emulsion. SO was dispersed with soybean phosphatidyl choline (PC) using sonication. The dispersal mechanism was evaluated by characterizing the dispersed particles using dynamic light scattering, fluorescence spectroscopy and surface monolayer techniques. The dispersions in SO fractions being in the range of 0.1‐0.7 were stable at room temperature for 3 d. A limited amount of SO was incorporated into PC bilayer membranes. The excess SO separating from the PC bilayers was stabilized as emulsion particles by the PC surface monolayer. When the PC content was lower (SO more than 0.8 mol‐%), the PC monolayer did not completely cover the hydrophobic SO particle surfaces. In this case, the particle size increased drastically and the separation into oil and water occurred. Therefore, the solubility between SO and PC and the coexistence of emulsion and liposomal particles are critical parameters for the stabilization of the particles in water.     

以冷榨茶油为基质制取护肤霜的最佳工艺条件及检测

采用单因素试验和正交试验以及感官评价的方法探讨冷榨茶油护肤霜的最佳生产工艺。以油相和水相的添加方式、乳化温度、乳化时间、搅拌速度为工艺条件进行试验。试验表明,冷榨茶油护肤霜最佳工艺条件为：水相分两次缓慢添加到油相,乳化温度为70℃,乳化时间为25min,搅拌速度为1400r/min。按照此工艺所制得的冷榨茶油护肤霜稳定性好,具有良好的润肤保湿、创伤修复、消炎止痒等护肤功能。成品色泽乳白,气味清香自然,组织形态均匀细腻,并具有一定的防腐作用。     

Separating Oil from Aqueous Extraction Fractions of Soybean

Previous research has shown that enzyme-assisted aqueous extraction processing (EAEP) extracts 88–90% of the total soybean oil from extruded full-fat soy flakes into the aqueous media, which is distributed as cream (oil-in-water emulsion), skim, and free oil. In the present work, a simple separatory funnel procedure was effective in separating aqueous skim, cream and free oil fractions allowing mass balances and extraction and recovery efficiencies to be determined. The procedure was used to separate and compare liquid fractions extracted from full-fat soy flour and extruded full-fat soy flakes. EAEP extracted more oil from the extruded full-fat soy flakes, and yielded more free oil from the resulting cream compared to unextruded full-fat soy flour. Dry matter partitioning between fractions was similar for the two procedures. Mean oil droplet sizes in the cream and skim fractions were larger for EAEP of extruded flakes compared to non-enzymatic AEP of unextruded flour (45 vs. 20 μm for cream; 13 vs. 5 μm for skim) making the emulsions from EAEP of extruded flakes less stable. All major soy protein subunits were present in the cream fractions, as well as other fractions, from both processes. The cream could be broken using phospholipase treatments and 70–80% of total oil in the extruded full-fat flakes was recovered using EAEP and a phospholipase de-emulsification procedure.