Effect of Different Deacidification Methods on Phytonutrients Retention in Deacidified Fractionated Palm Oil

Crude red palm oil of 11.4 % free fatty acid content was dry fractionated to obtain liquid crude red palm olein which was deacidified using enzyme (lipase from Rhizomucor miehei), solvent (ethanol), and chemical (aqueous sodium hydroxide), and its effect on physicochemical characteristics and phytonutrients retention was evaluated. Enzymatic deacidification showed 100 % product yield and no neutral lipid loss, whereas yields of 78 and 62 % and neutral lipid loss of 12 and 30 % were observed for solvent and chemical deacidification, respectively. Variation in viscosity (25.3–37.2 cSt at 40 °C), slip melting point (15–36 °C), monoacylglycerols (1.7–3.3 %), and diacylglycerols (5.8–27.9 %) were also observed. Carotenoid content was slightly reduced by enzymatic (535 mg/kg), solvent (556 mg/kg), and chemical (526 mg/kg) deacidification. Retention of phytonutrients such as phytosterols (1,235 mg/kg), total tocopherols (965 mg/kg), squalene (301 mg/kg), coenzyme Q₁₀ (25.9 mg/kg), and total phenolics (3 mg/kg) was highest following enzymatic deacidification. The IC₅₀ value of the enzymatic deacidified sample (21.8 mg/ml) indicates more radical scavenging activity than in samples obtained using solvent (42.0 mg/ml) and chemical (28.8 mg/ml) methods.     

Low temperature deodorizations of fish oils with volatile acidic and basic steam sources

Menhaden, cod liver and siscowet lake trout oils were vacuum steam deodorized at 100°C to 210°C using volatile acid (acetic and hydrochloric) and base (ammonium hydroxide) solutions (0.005N–0.25N) as steam sources. Volatiles in oils were analyzed by Tenax GC headspace analysis, and flavor and odor quality was evaluated. Deodorization of oils at 100°C with acidic solutions yielded oils that lacked the burnt/fishy flavors compared to similar oils that were deodorized with either water or alkaline solutions. Acid catalyzed hydrations of fishy aldehydes by deodorizing acids and flavor masking byt,c-2,6-nonadienal appeared to cause the suppression of fishy flavors in fish oils deodorized by acid solutions. Oils deodorized at 210°C exhibited less intense fishy flavors, and lower concentrations of fishy aldehydes,t,t,c-2,4,7-decatrienal,t,c,c,-2,4,7-decatrienal, andc-4-heptenal.     

Supercritical CO2 degumming and physical refining of soybean oil

A hexane-extracted crude soybean oil was degummed in a reactor by counter-currently contacting the oil with supercritical CO₂ at 55 MPa at 70°C. The phosphorus content of the crude oil was reduced from 620 ppm to less than 5 ppm. Degummed feedstocks were fed (without further processing,i.e., bleaching) directly to a batch physical refining step consisting of simultaneous deacidification/deodorization (1 h @ 260°C and 1–3 mm Hg) with and without 100 ppm citric acid. Flavor and oxidative stability of the oils was evaluated on freshly deodorized oils both after accelerated storage at 60°C and after exposure to fluorescent light at 7500 lux. Supercritical CO₂-processed oils were compared with a commercially refined/bleached soybean oil that was deodorized under the same conditions. Flavor evaluations made on noncitrated oils showed that uncomplexed iron lowered initial flavor scores of both the unaged commercial control and the CO₂-processed oils. Oils treated with .01% (100 ppm) citric acid had an initial flavor score about 1 unit higher and were more stable in accelerated storage tests than their uncitrated counterparts. Supercritical CO₂-processed oil had equivalent flavor scores, both initially and after 60°C aging and light exposure as compared to the control soybean oil. Results showed that bleaching with absorbent clays may be eliminated by the supercritical CO₂ counter-current processing step because considerable heat bleaching was observed during deacidification/deodorization. Colors of salad oils produced under above conditions typically ran 3Y 0.7R.     

Deacidification of olive oils by supercritical carbon dioxide

An investigation of the application of supercritical carbon dioxide (SC-CO₂) extraction to the deacidification of olive oils has been made to verify that the nutritional properties of the oil remain unchanged when this technique is applied. Preliminary runs at 20 and 30 MPa in the temperature range of 35–60°C were performed on fatty acids and triglycerides as pure compounds or mixtures, to determine their solubility in SC-CO₂. The solubility data obtained show that CO₂ extracts fatty acids more selectively than triglycerides under specific conditions of temperature and pressure (60°C and 20 MPa). It has been noted that the physical state of the solutes plays an important role in determining the solubility trends as a function of temperature and pressure. Extraction of free fatty acids from olive oil was performed on samples with different free fatty acid (FFA) contents at 20 and 30 MPa and at 40 and 60°C. Experimental data suggest that the selectivity factor for fatty acids is higher than 5 and increases significantly as the fatty acid concentration of the oil decreases. For a FFA content of 2.62%, the selectivity reaches a value of 16. In order to evaluate any variations in the composition, several SC-CO₂ extractions of husk oil with high FFA content (29.3%) were made. The results show that selectivity is still significant (≈5) and the composition in the minor component of the deacidified oil has not changed. On the basis of the experimental results and preliminary process evaluations, the authors conclude that SC-CO₂ extraction could be a suitable technique for the deacidification of olive oils, especially for oils with relatively high FFA (<10%).     

Enzymatic Deacidification of Vegetables Oils

Vegetable oils with high content of free fatty acids can be deacidified satisfactorily by enzymatic esterification process under optimum conditions of temperature, pressure and enzyme amount. The enzymatic deacidification process can be a new process of deacidification.     

Über die Bildung von Artefakten bei der Dämpfung von Speiseölen und -fetten

The Formation of Artefacts during Deodorization of Fats and Oils Various artefacts are formed during deodorization of fats and oils. Their amount depends on the process parameters, particularly temperature and time of deodorization. The design of the equipment as well as the fatty acid composition of the fats and oils also have some influence. We investigated the formation of trans-isomers as well as of dimeric or oligomeric triglycerides in various fats and oils of different degree of unsaturation by means of IR-spectrometry and capillary GLC on one hand and by gel permeation chromatography on the other hand. The amount of the formation of artefacts is insignificant up to 240°C. At somewhat higher temperatures the amount clearly increases and in the temperature range 260-270°C a steep increase can be observed. Under process conditions as applied in the industrial practice of to-day objectionable concentrations of artefacts are never formed.     

Composition and sensory qualities of minimum-refined soybean oils

Commodity (normal) and high-oleic soybean oils extracted by extrusion-expelling (E-E) were minimally processed using water degumming and adsorptive deacidification to produce edible oil. Degummed and deacidified oils were deodorized at 150°C for 1 h by purging with N₂, CO₂, or steam. They were also conventionally deodorized for quality comparisons. Generally, the oxidative stability of the properly gas-purged commodity oils was better than that of the conventionally deodorized oils. Total tocopherols, FFA contents, and colors of the deodorized oils were not significantly different among the treatments. Sensory analysis of the oils showed that the toasty/nutty flavors of the gas-purged oils, especially for the degummed oils, were more intense than those of the conventionally deodorized oils. The beany flavors of gas-purged oils were not significantly different from those of conventionally deodorized oils, although the flavor intensities tended to be slightly higher in gas-purged oils. The overall flavor intensities of the gas-purged oils were similar to those of conventionally deodorized oils. Therefore, E-E soybean oil has the potential to be minimally refined to produce edible oil with good compositional and sensory qualities.     

Dekontamination von Ölen, Ölsaaten und -früchten von Cäsium-137

Decontamination of Oils, Oilseeds and Oil-Bearing Fruits from Caesium-137 It was shown by model experiments that caesium-137 is removed partly from raw oils and fats during deacidification and to a considerable extent during bleaching. Totally contaminated oilseeds and oil-bearing fruits can be freed from caesium-137 by diffusion, for which 10% sodium chloride or potassium chloride solutions were used. Recirculation and continuous removal of caesium ions which have already entered in the solution intensify and accelerate the decontamination. The attainable degree of decontamination is dependent on the plant material to be treated.     

Deacidification of black cumin seed oil by selective supercritical carbon dioxide extraction

The deacidification of high-acidity oils from Black cumin seeds (Nigella sativa) was investigated with supercritical carbon dioxide at two temperatures (40 and 60°C), pressures (15 and 20 MPa) and polarities (pure CO₂ and CO₂/10% MeOH). For pure CO₂ at a relatively low pressure (15 MPa) and relatively high temperature (60°C), the deacidification of a highacidity (37.7 wt% free fatty acid) oil to a low-acidity (7.8 wt% free fatty acid) oil was achieved. The free fatty acids were quantitatively (90 wt%) extracted from the oil and left the majority (77 wt%) of the valuable neutral oils in the seed to be recovered at a later stage by using a higher extraction pressure. By reducing the extraction temperature to 40°C, increasing the extraction pressure to 20 MPa, or increasing the polarity of the supercritical fluid via the addition of a methanol modifier, the selectivity of the extraction was significantly reduced; the amount of neutral oil that co-extracted with the free fatty acids was increased from 23 to 94 wt%.     

Über die Herstellung der Imidazoline von Fettsäuren

Preparation of Imidazolines of Fatty Acids The formation of imidazolines was studied in the reaction of diethylene triamine with fatty acids and oils. With the aid of IR- and UV-spectroscopy, it could be proved that imidazolines are formed at temperatures between 150° - 200° C. Aminoamides are also formed at these temperatures. Above 280° C, decomposition takes place, and low molecular nitrogen compounds, including probably ammonia, are formed.     

Addition of ferulic acid,ethyl ferulate,and feruloylated monoacyl- and diacylglycerols to salad oils and frying oils

To determine antioxidative effects of ferulic acid and esterified ferulic acids, these compounds were added to soybean oils (SBO), which were evaluated for oxidative stability and frying stability. Additives included feruloylated MAG and DAG (FMG/FDG), ferulic acid, ethyl ferulate, and TBHQ. After frying tests with potato chips, oils were analyzed for retention of additives and polar compounds. Chips were evaluated for hexanal and rancid odor. After 15 h frying, 71% of FMG/FDG was retained, whereas 55% of ethyl ferulate was retained. TBHQ and ferulic acid levels were 6% and <1%, respectively. Frying oils with ethyl ferulate or TBHQ produced significantly less polar compounds than SBO with no additives. Chips fried in SBO with TBHQ or ferulic acid had significantly lower amounts of hexanal and significantly less rancid odor after 8 d at 60°C than other samples. Oils were also aged at 60°C, and stability was analyzed by PV, hexanal, and rancid odor. Oils with TBHQ or FMG/FDG had significantly less peroxides and hexanal, and a lower rancid odor intensity than the control. FMG/FDG inhibited deterioration at 60°C, whereas ethyl ferulate inhibited the formation of polar compounds in frying oil. Ferulic acid acted as an antioxidant in aged fried food. TBHQ inhibited oil degradation at both temperatures. Presented at the 94th AOCS Meeting & Expo, Kansas City, MO, May 4–7, 2003.     

Untersuchungen zur Stabilität des Tocopherolgehaltes pflanzlicher Öle

Stability of Tocopherols in Vegetable Oils Tocopherols in crude vegetable oils are partially destroyed by technological treatments. A further decomposition during storage is possible by influence of light, oxygen and temperature. The influence of these parameters of total tocopherol content and tocopherol distribution was studied in several refined and cold pressed oils during a 12 weeks storage time. The tocopherols showed good stability at low temperature (4°C). When kept at room temperature (20–35°C), an additional effect of light was of greater influence (higher decrease of the content) than the additional effect of air oxygen. The stability at low temperature was found to be α-T>γ-T, at room temperature γ-T>α-T.     

Maximierung der Samenerträge und wertgebenden Inhaltsstoffe von Fenchel (Foeniculum vulgare M.) I

Maximizing the Yield of Seeds and the Yield of Petroselinic Acid and Essential Oils of Fennel (Foeniculum vulgare M.) I It was the object of this trials to maximize the yield of seeds and the yield of petroselinic acid and essential oils of fennel with a comparison of cultivation and freely sowen seeds, with optimum amount of nitrogen and adapted harvest times in dependence of different ecological conditions. Fennel was investigated in 1990 and 1991 at 2 locations in Durmersheim (Rheintal) and Ensmad (Schwäbische Alb) with an average temperature of 9.8°C and 6.9°C over many years. With cultivation instead of freely sowen seed, fennel obtained in Durmersheim the highest seed yields in both years. The highest yields of petroselinic acid and essential oils were achieved with both, cultivation and freely sowen variants. In Ensmad only the cultivation-variants developed harvestable seeds. With an increase of N-application fennel attained a higher seed yield. The N-application induced a higher yield of petroselinic acid and of essential oils, too. During the maturity of the fennel fruits the seed yield and the yield of petroselinic acid and of essential oils decreased.     

Effect of processing on the oxidative stability of low erucic acid turnip rapeseed (Brassica rapa) oil

The effect of various processing conditions on the composition and the oxidative stability of mechanically pressed (90–95°C) rapeseed oil was investigated. The five different rapeseed oils included crude (nondegummed), superdegummed, steam stripped (at 140°C for 4h, nondegummed), physically refined (degummed, bleached and deodorized at 240°C), and cold pressed (40°C) oils. Oils were autoxidized in the dark at 60°C and under light at 25°C. Oxidation was followed by measuring changes in the peroxide values (PV) and the consumption of tocopherol and carotenoid was measured. In the dark the oils reached PVs of 10 meq/kg in the order: cold pressed > superdegummed > steam stripped ≅ crude > refined. However, under light conditions the order changed as follows: cold pressed > crude ≅ steam stripped > superdegummed > refined. Processing had no effect on fatty acid composition nor α-tocopherol content of the oils. Superdegumming and steam stripping decreased the carotenoid content of the oils while cold pressing and refining reduced also chlorophyll, γ-tocopherol and phosphorus content of the oils.     

Oxidation of phytosterols in a test food system

The oxidative stability of phytosterols in canola, coconut, peanut, and soybean oils was examined under simulated frying conditions of 100, 150, and 180°C for 20 h. The degree of oxidative decomposition was assessed by the loss of phytosterols, accumulation of phytosterol oxides, and the change in fatty acid profiles. The phytosterol oxides produced in the oils were identified using mass spectroscopy. Oils with higher levels of polyunsaturated fatty acids showed greater amounts of sterol loss; however, the sterol loss was less complete than in the more saturated oils. A greater variety of sterol oxides was observed at the lower temperatures of 100 and 150°C compared to 180°C. This study demonstrates that under conditions similar to frying, there is a loss of phytosterols and polyunsaturated fatty acids. The accumulation of phytosterol oxides may be temperature-limited because of further break-down into products not measurable by typical gas chromatography-mass spectrometry techniques.     

Über die Möglichkeiten der Raffination von Sonnenblumenöl mittels Molekulardestillation

The Possibilities of Refining Sunflower Oil with Molecular Distillation The experiment on the deacidification of sunflower oil with molecular distillation was extended to the total refining of the oil. The elimination curve of cold pressed oil is determined, the region of deacidification found out, the distillates and the residues, obtained after distillation, analysed and also the vitamine-E contents of the same are examined. The possibility of refining the cold pressed oil by repeated distillations in a small laboratory apparatus as well as in a semi-industrial plant was studied. The sunflower oil can be refined by molecular distillation in a one step process even at 40° to 50° C. At this temperature, the acid value of the oil remains under 1 and the peroxide value under 10.     

The effects of roasting temperatures on the formation of headspace volatile compounds in perilla seed oil

Volatile compounds of perilla seed oils roasted at different temperatures (150–190°C) were analyzed by dynamic headspace gas chromatography-mass spectrometry. The headspace volatiles in roasted perilla seed oils (RPSO) were composed of thermally produced flavors and compounds originating from the raw perilla seeds. The roasting temperatures significantly affected the production of thermal reaction flavors. Oils from parilla seeds roasted below 170°C had relatively high concentrations of aldehydes, whereas pyrazines and furans were the predominant volatiles above 170°C. In all of the RPSO, the contents of both perilla aldehyde and perilla ketone remained almost constant and might be used to discriminate perilla seed oils from other roasted vegetable seed oils.     

Effects of neutralization with lime on the quality of acid olive oil

The technique described in this study makes it possible to neutralize olive oils having very high acidities. The neutralization is carried out in a solid-liquid biphasic medium, which is slightly hydrated, by substituting lime (calcium hydroxide, an inexpensive and locally manufactured product) for soda (sodium hydroxide) as the neutralizing agent. Neutralization by lime limits TAG hydrolysis. The use of lime as a neutralizing agent makes it possible to preserve almost 80% of the α-tocopherol. Oils neutralized with lime have higher temperatures of thermal decomposition than oils neutralized with soda. Oils neutralized with lime had better oxidative stability because natural antioxidants were preserved. Oils neutralized by lime conformed with international olive oil standards.     

Über ein neues Verfahren zur kontinuierlichen Entsäuerung natürlicher Speiseöle und Fette durch Extraktion mit verdünnter Alkalilauge

A New Process for the Continuous Deacidification of Edible Oils and Fats by Extraction with Dilute Alkali Solution The known technical process for the deacidification of natural oils and fats, and hardened fats, using dilute alkali in batch operation is associated with certain difficulties. Ziehl's extraction column provided with moving elements permits a continuous operation of the aforesaid process with short hold-up time, low space requirement and considerably less saponification loss. The different operations involved, e. g. deacidification, washing with salt solution and with water, are carried out in the same unit.     

Löslichkeitsverhalten von fetten Ölen in komprimiertem Kohlendioxid im Druckbereich bis 2600 bar

Solubility Behaviour of Fatty Oils in Dense Carbon Dioxide in the Pressure Range up to 2600 bar Different possibilities to determine the phase equilibrium are shown. A dynamic procedure is developed which allows to evaluate solubility data of fatty oils in dense gases. Construction, functioning and handling of the apparatus are described with which the solubility of soybean oil in dense carbon dioxide is examined in the pressure range up to 2600 bar and in a temperature intervall between 25°C and 80°C. The formation of solubility maxima at a interval between 25°C and 80°C. The formation of solubility maxima at a gas density of 1.06 g/cm³ is found out. The facts which influence the solubility behaviour are discussed and the importance of the results for the extraction of oil seeds is given thought.