The determination of vitamin d in margarine by high performance liquid chromatography

Margarine manufactured in South Africa contains vitamin D added at a level of 1-3 international units per gram. Because of the high ratio of lipid to vitamin D, it is difficult to determine the vitamin content for control purposes. A high performance liquid Chro-matographic method for the determination of vitamin D in mar-garine is proposed. The unsaponifiable fraction of a margarine sample is chromatographed twice on an adsorption system. The vitamin D fraction collected from this column is finally injected onto a reverse phase system where vitamins D₂ and D₃ are separated and quantitated with an ultraviolet detector. Vitamin D₂ is used as an internal standard for vitamin D₃ or vice-versa, depending on the form of the vitamin added to margarine. The recovery of 100 ng/g vitamin D₃ added to a margarine mix was 100.1% (coefficient of variation 13.2% for 12 replicates) as calculated from the ratio of peak areas. The detection limit is 1 ng vitamin D. Results for 3 samples of margarine and one sample of butter are given.     

The effect of antioxidants on butter in relation to storage temperature and duration

The effects of antioxidants on the oxidative stability of butter, under different storage time and temperature conditions, were evaluated. Natural (α‐tocopherol) and synthetic (BHA and BHT) antioxidants were added to the butter samples at two concentrations (50 and 100 ppm) immediately after the butter samples were produced from the pasteurised sweet cream, after which they were kept in the dark at 4 and ?20 °C for 6 months. Peroxide value (PV) and thiobarbituric acid (TBA) number and the residual antioxidants of the samples were examined at 30‐day intervals, starting on the second day until the end of the storage period. The measurements obtained by assaying PV and TBA number in butter samples showed that both the synthetic and natural antioxidants used were capable of protecting the butter samples against oxidation during storage at both temperatures. The butter samples with 50 ppm antioxidant could be stored for more than 180 days at 4 °C without spoilage. At ?20 °C, the addition of BHA, BHT and α‐tocopherol caused a reduction in the TBA number from 0.31 (control) to 0.21, 0.23 and 0.27 mg malonaldehyde/kg butter, respectively, and the PV decreased from 0.75 (control) to 0.46, 0.56 and 0.54 meq O₂/kg butter, respectively, after 6 months of storage. The highest residue values were determined in both the 100 and 50 ppm α‐tocopherol‐containing samples. These results indicate that α‐tocopherol exhibited a very strong antioxidant activity, which was almost equal to that of the synthetic antioxidants. Therefore, the use of α‐tocopherol is recommended as a natural antioxidant to suppress the development of rancidity in butter.     

Cholesterol oxides in swedish foods and food ingredients: Butter and cheese

Fresh butter manufactured by batch or continuous technologies in Sweden contained only traces of 7-ketocholesterol at the detection limit (0.1 ppm in the lipids) and no detectable levels of other common cholesterol oxides. Storage at 4°C for up to four mo caused an increase in the levels of the isomeric 5,6-epoxycholestanols, the epimeric 7-hydroxycholesterols, 20α-hydroxycholesterol and 7-ketocholesterol as revealed by Lipidex chromatography, TEAP-Lipidex chromatography and GLC. Heating of butter for 10 min at the temperature interval 150–200°C under conditions similar to that in shallow-pan kitchen frying caused a gradual increase in the total amount of cholesterol oxides from 0 to 2.5 ppm, while at 200°C the total amount of cholesterol oxides was 1.6 ppm. Butter heated five min at 200°C also had less cholesterol oxides than that heated at 190°C for 10 min. Industrially manufactured butter oil and cream oil contained only low levels of some of the cholesterol oxides. Further, three types of processed cheese (soft-melted, hard-melted and grated cheese) were investigated. The soft-melted and the hard-melted cheese types contained only traces of some of the oxides, while the grated cheese samples had 0.5–2.2 ppm of the total cholesterol oxides in the lipids.     

The measurement of the hardness of margarine and fats with cone penetrometers

Summary In order to be able to compare the results of hardness measurements on margarine, fats, shortenings, etc., measured both with cone penetrometers and other rheological instruments, several measurements have been made with various cones and samples. The results obtained showed that the yield value can be calculated from the following formula: C=KW/p^1.6 in which C=yield value K=factor dependent on the angle of the cone p=the penetration depth in 0.1 mm. at a penetration during 5 seconds W=the weight of the cone (grams) This formula appeared to apply for cones with angles between 15 and 90° over a very wide hardness range (between 45 and 8300 g./cm²) for margarine, fat, shortening, and butter. The advantages of the proposed procedure for determining the yield value are that is is an objective measure instead of a “thumb test;” results obtained with various cones can be compared; and this method is highly suitable for standardizing.     

Dispersed phase destabilization in table spreads

Commercially available butter, regular-fat margarine, and a fat-reduced margarine (38% fat w/w) were stored between 10 and 35°C for up to 4 d to elaborate on the relationship between droplet size and solid fat content (SFC) that exists in these spreads. At 10°C, the mean volume-weighted droplet size for butter was 4.22±0.40 μm followed by margarine (6.22±0.10 μm) and fat-reduced margarine (12.62±0.28 μm). At higher temperatures, as a result of decreasing SFC, the mean droplet size increased as did the droplet size distribution, leading to eventual coalescence and destabilization in all spreads. In butter, the critical SFC was ∼9%, whereas in margarine notable coalescence occurred at ∼5% SFC. The fat-reduced margarine destabilized at lower temperatures than the other spreads (∼20°C vs. ∼30°C), at an SFC of ∼6.5%. In these spreads, two different mechanisms influenced dispersed phase stability: (i) steric stabilization against coalescence via fat crystals located at the droplet interface, known as Pickering stabilization, and (ii) stabilization against droplet sedimentation (and droplet encounters) due to the presence of the fat crystal network.     

Changes in the Contents of Cholesterol and Cholesteryl Esters Occurring during Lipase-Catalysed Interesterification Reactions

The free cholesterol and cholesteryl esters isolated on silica column and the total cholesterol from saponified fat samples obtained from untreated butter fat and butter fats interesterified with Pseudomonas fluorescens lipase as catalyst were determined on immobilised OV-351 and phenylmethylsilicone gas chromatographic columns. Fatty acid composition of the cholesteryl esters of the untreated butter fat differed markedly from the fatty acid composition of acylglycerols. The proportions of cholesteryl palmitate, stearate and oleate were clearly higher in the interesterified fats and the proportion cholesteryl linoleate was distinctly lower. Determination of the free cholesterol and cholesteryl esters and the total cholesterol in the fraction of unsaponifiables revealed that, on average, 89% of cholesterol is esterified in the interesterification products, but only 2% in intact butter fat.     

Trace metals and the flavor stability of margarine

Traces of copper, iron and other metals are present in the oil and the salt used for margarine. The presence of these metals, which act as powerful catalysts for fat oxidation, decreased the flavor stability. Analyses were done by atomic absorption spectroscopy after ashing of 400 g oil and margarine samples. Storage tests are reported with laboratory samples to which different amounts of trace metals had been added, and also with plant production samples. Levels of 0.1 ppm copper led to rapid flavor deterioration. In order to expect good flavor stability, the maximum copper amounts which can be tolerated are about 0.02 ppm. Aside from the importance of having all equipment free of copper, the use of salt low in trace metals or the additions of metal chelating agents are ways to extend the shelf life. The addition of 75–100 ppm EDTA salts as sequestering agents was found to increase the flavor stability of margarine samples significantly. One of 28 papers presented at the Symposium, “Metal-Catalyzed Lipid Oxidation,” ISF-AOCS World Congress, Chicago, September 1970.     

CLA-Rich Soy Oil Margarine Production and Characterization

A heterogeneous catalysis method to produce 20 % conjugated linoleic acid (CLA)-rich food-grade soy oil in 2 h without solvents or gases was recently developed. The objective of this study was to produce and characterize CLA-rich soy oil margarine relative to a soy oil control and commercial margarine. CLA-rich soy oil was used to prepare margarine. The samples were characterized for firmness, rheology, thermal behavior, solid fat content (SFC) and microstructure and compared with a soy oil control and commercial margarine. The CLA-rich oil margarine firmness and rheological properties were similar to commercial margarine and provided a better texture relative to the soy oil control margarine. However, SFC, droplet size distribution and melting behavior of CLA-rich oil margarine were similar to control soy oil margarine and dissimilar to the commercial product. This suggests that hardness and rheological properties of margarine are not solely dependent on SFC and melting behavior. Lipid composition, polymorphism and microstructure differences in CLA-rich oil margarine may play an important role on the texture and rheological properties. A 7-g typical serving of the CLA-rich oil margarine will provide 0.6 g CLA. Thus five servings will provide 3.2 g/day of CLA and 185 calories/day, which is well within the maximum recommended 700–980 fat calories/day.     

Influence of Fat and Emulsifier Content on Volatile Release of Butter Aroma Used in Water Phase and Physical Attributes of Model Margarines

Margarines are water‐in‐oil (W/O) emulsion‐type products produced with butter aroma. The aim of this study is to investigate the volatile release of the butter aroma compounds used in the water phase of model margarine and sensory properties influenced by the change of fat and emulsifier. A headspace/solid phase microextraction/gas chromatography/mass spectrometry (HS/SPME/GC/MS) system is used for the identification of the volatile compounds. It is determined that high fat content in model margarine samples results in an increase in the release of both 2,3‐butandione and butanoic acid. On the other hand, an increase in fat content reduces the release of butanoic acid ethyl ester and vanillin. In addition, an increase in the emulsifier content of the model margarines results in a decrease in butanoic acid ethyl ester release. The model margarines with 80% fat content have the highest hardness and storage modulus (G′) values. The perception of butter aroma and taste are more intense in high‐fat margarine samples, while fruity aroma and taste, vanilla aroma, and taste perception are higher in low‐fat margarine samples. However, emulsifier content does not affect the sensory properties of the model margarines. Practical Applications: Decreasing high fat content food intake has become increasingly popular among consumers. Thus, in order to meet consumer demands, manufacturers have begun to reduce the fat content of the foods they produce. However, the flavor properties of a product can change as a consequence of fat content reduction. In order to produce a product in accordance with the properties demanded by the consumer, the change in the flavor of that product should be foreseen depending on the change in fat content. This study aimed to determine the volatile compound release and sensory properties of margarine samples due to fat and emulsifier changes. The findings of this study are a guide for the production of low‐fat products.     

Margarine from Organogels of Plant Wax and Soybean Oil

Organogels obtained from plant wax and soybean oil were tested for their suitability for incorporation into margarine. Sunflower wax, rice bran wax and candelilla wax were evaluated. Candelilla wax showed phase separation after making the emulsion with the formulation used in this study. Rice bran wax showed relatively good firmness with the organogel, but dramatically lowered firmness for a margarine sample. Sunflower wax showed the greatest firmness for organogel and the margarine samples among the three plant waxes tested in this study. Firmness of the margarine containing 2–6 % sunflower wax in soybean oil was similar to that of margarine containing 18–30 % hydrogenated soybean oil in soybean oil. The firmness of commercial spread could be achieved with about 2 % sunflower wax and that of commercial margarine could be achieved with about 10 % of sunflower wax in the margarine formulation. Dropping point, DSC and solid fat content of the new margarine containing 2–6 % sunflower wax showed a higher melting point than commercial margarine and spreads.     

A study of odor stability of commercial stearic acid through isolation and identification of its volatile odoriferous compounds

Commercial stearic acid may have an iodine value of less than 0.5. However, it develops a characteristic objectionable odor quite rapidly, sometimes before a shipment has reached its destination. The present investigation is an identification of the volatile odoriferous compounds which are responsible for this undesirable odor. Volatile compounds were isolated from commercial stearic acid and separated into acidic and nonacidic compounds. The acidic fraction did not have the characteristic off-odor of the commercial stearic acid and was discarded. The nonacidic fraction was fractionated into pure compounds by repeated gas chromatography, which then were identified by a combination of gas chromatographic retention time and IR and mass spectrometry. A total of 52 compounds was identified positively. They contained a relatively large number of lactones, viz, 7 γ-lactones, 4 δ-lactones, and 2 γ-2-ene lactones. The other identified compounds were 11 saturated hydrocarbons, 7 saturated primary alcohols, 6 saturated methyl ketones, 10 saturated normal aldehydes, 4 saturated esters, and 1 diphenyl ether. In addition, 2 saturated aldehydes and 1 γ-3-ene lactone were identified tentatively. The odors of the saturated and unsaturated lactones were reminiscent of the objectionable odor characteristic of commercial stearic acid. Quantitative estimation indicated that commercial stearic acid contained: 0.47 ppm of 4-hydroxy-hexanoic acid, lactone; 0.06 ppm of 4-hydroxy-heptanoic acid, lactone; 0.31 ppm of 4-hydroxy-octanoic acid, lactone; 0.06 ppm of 4-hydroxy-nonanoic acid, lactone; and 0.53 ppm of 4-hydroxy-undecanoic acid, lactone. Paper of the Journal Series, New Jersey Agricultural Experiment Station, Cook College, Rutgers, The State University of New Jersey, Department of Food Science, New Brunswick, N.J. 08903.     

Silver-complexation liquid chromatography for fast,high-resolution separations of triacylglycerols

A high-speed, high-resolution approach to silvercomplexation chromatography of triacylglycerols in vegetable fats and cocoa butter equivalents is described. Trisaturated and major isomeric unsaturated species with up to five double bonds are eluted within 12 min. A simple change of solvent composition enables elution of species with up to nine double bonds within the same time-frame. Throughput is three samples/hr (70 samples/24 hr with an automatic system). Short-term reproducibility of analytical data for the system gives standard deviations similar to those obtained in practice for high-resolution capillary gas chromatography of triacylglycerols, and quantitative accuracy is good. Details of column preparation, solvent gradient and system operation are given.     

Margarines Produced From Rice Bran Oil and Fractionated Palm Stearin and Their Characteristics During Storage

Rice bran oil (RBO) usage in Southeast Asia is increasing. The purpose of this study was to incorporate RBO in margarine as a replacement for common oils such as soybean oil. The physicochemical properties of blends of RBO and fractionated palm stearin (FPS) at eleven different weight ratios (from 0:100 to 100:0) were characterized. Results showed that fat blends with ratios of 10:90, 20:80, and 30:70 RBO:FPS were semisolid at ambient temperature, with solid fat contents and a crystal morphology similar to commercial margarine fats. Blends containing ≤30% RBO were made into margarines and compared against commercial margarine over 8 weeks of storage. The margarine with a 20:80 RBO:FPS fat phase was stable against coalescence and phase separation while demonstrating acceptable spreadability and whippability at ambient temperature. Fat crystals in this blend were in the β′ polymorph at all time points during storage, which is a desired characteristic in margarine. This study showed that RBO may be effectively used for margarine production.     

6-Pentyl-2H-pyran-2-one: A Potent Peach-Derived Kairomone for New Zealand Flower Thrips,Thrips obscuratus

New Zealand flower thrips, Thrips obscuratus (Thysanoptera: Thripidae), are attracted to ripening fruits, especially peaches. Volatiles from unripe and ripe peach fruits were collected and analyzed by gas chromatography/mass spectrometry. Six lactones were found only in ripe peach volatiles: γ-heptalactone, γ-octalactone, γ-nonalactone, 6-pentyl-2H-pyran-2-one, γ-decalactone, and δ-decalactone. When these compounds were tested individually in field-trapping experiments, three of them (γ-octalactone, γ-nonalactone, and 6-pentyl-2H-pyran-2-one) attracted New Zealand flower thrips. In another field-trapping experiment, aimed at testing various combinations of the three active compounds, no synergistic effects were found among all combinations tested; no combination caught more thrips than 6-pentyl-2H-pyran-2-one, alone. A further field-trapping experiment was conducted to determine the dose (10, 100, and 500 mg) of 6-pentyl-2H-pyran-2-one that gave the greatest catch of T. obscuratus, while also comparing it against another attractant, ethyl nicotinate, for T. obscuratus. The greatest catches in traps baited with either attractant were at loadings of 500 mg. At both 10 and 500 mg, traps baited with 6-pentyl-2H-pyran-2-one caught more T. obscuratus than those baited with the same amounts of ethyl nicotinate. 6-Pentyl-2H-pyran-2-one is a potent attractant for New Zealand flower thrips and, therefore, could be used for monitoring and control of New Zealand flower thrips. Work is underway developing monitoring and control options utilizing 6-pentyl-2H-pyran-2-one for this important pest.     

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.     

A micromethod to generate and collect odor constituents from heated cooking oils

A small stainless steel reactor about one-millionth the volume of a home kitchen, was built to generate odors from cooking oils heated to deep fat frying temperatures. This “microroom” was designed so that volatiles could be collected from 1–5 ml of heated oils (193 C) directly on a gas chromatographic column, cooled to -60 C and subsequently separated by temperature programing up to 250 C. Evaluations showed that heated oil odors from the microroom were similar to those room odors produced by heating to 193 C 300 ml of cooking oil in an open vessel; exposure to subambient conditions did not affect the separation efficiency of the gas chromatographic column. Provisions were made for three independent means of effluent monitoring: flame ionization detection, odor analyses and mass spectrometry. Presented at the AOCS Meeting, Los Angeles, April 1972. ARS, USDA.     

Comparison of two methods for the direct determination of fat in butter,blended spreads,and margarine

A German (GE) method and a New Zealand (NZ) method for the direct determination of total fat in spreadable fats were compared in a pilot collaborative study to obtain preliminary information regarding the precision and the level of fat content determined. The study comprised six products, including butter, blended fat products, and margarine with a fat content in the range of 39—82%, and four laboratories. The GE method, based on a Soxhlet extraction using petroleum ether, yielded a repeatability estimate of 0.41 g/100 g and a reproducibility estimate of 0.79 g/100 g. The NZ method, based on an extraction of the fat by thorough shaking of the sample with petroleum ether followed by phase separation, yielded a repeatability estimate of 0.32 g/100 g and a reproducibility estimate of 0.62 g/100 g. The difference in precision estimates between the two methods was significant for repeatability, but not for reproducibility. The better repeatability of the NZ method was probably partly due to the use of a superior sample preparation procedure which ensured that any inhomogeneity developed inside the sample container during transport or storage was removed. The average fat content as determined by the NZ method was 0.20 g/100 g higher than that determined by the GE method, but for individual samples no constant bias was observed. However, an inverse correlation between the bias and the fat content of the product suggested that the anhydrous sodium sulphate used in the GE method interfered with the fat recovery when analysing samples containing a high percentage of water. Thus, according to this study, the NZ method seems to have certain advantages over the GE method with respect to the results obtained.     

Identification and quantification of cholesterol oxides in grated cheese and bleached butteroil

Butteroil samples bleached with benzoyl peroxide (BP) and 17 commercial cheeses were screened for oxidized sterols by thin layer chromatography (TLC). Ungrated cheeses made from bleached milk and freshly bleached butteroil contained no detectable oxidized sterols. Oxidized sterols were detected in stored, bleached butteroils and in grated cheeses. Four major oxidation products were the isomeric 5,6-epoxycholesterols and the epimeric 7-hydroxycholesterols identified by TLC, high performance liquid chromatography (HPLC) and mass spectrometry (MS). Additional sterol oxides (tentatively identified and not quantified) present in these samples included low levels of 7-ketocholesterol and cholesta-3,5-dien-7-one. The epimeric 7-hydroxycholesterols were detected in bleached butteroils stored in air (BP-A) and nitrogen (BP-N) for 22 days at 15 C. Butteroil, after 90 days of storage at 15 C, had 30 (BP-N) and 60 (BP-A) μg total oxides/g of bleached oil and, after 1-year at −20 C, had 70 (BP-N) and 180 (BP-A) μg/g butteroil. A grated, unbleached cheese packaged in clear glass contained the most oxidized sterols (44 μg/g). Sterol oxides were not detected in bleached cream using a simulated industrial process.     

CLA‐Rich Soy Oil Shortening Production and Characterization

Conjugated linoleic acid‐rich soy oil (CLARSO) has been shown to have numerous health benefits, including anti‐obesity and anti‐carcinogenic properties. This oil was previously used to produce CLA‐rich margarine that showed physical characteristics similar to commercially available margarine. The objective of this study was to produce CLA‐rich shortening and analyze its physical properties relative to commercially available shortenings and soy oil control shortenings. The shortenings were prepared and their rheology, thermal behavior, and solid fat content (SFC) were determined and compared to the commercial samples. The CLA‐rich shortening samples showed similar rheological properties to the commercial samples and showed a better consistency (more solid‐like behavior) compared to the soy oil control samples. In addition, the CLA‐rich shortenings also have a higher SFC (% SFC) as well as higher latent heat of crystallization and melting than the soy oil controls indicating a comparatively higher crystalline fraction. Thus, CLARSO produced firmer shortenings than did conventional soy oil by interacting with the crystallizing stearin fraction and consequently increasing the crystalline mass fraction without significantly altering the microstructure kinetics of solid fat crystallization.