Uses of Sunflower Oil

In 2000-2001, Argentina produced 1.60 MMT of sunflower oil and exported 1.18 MMT (of that oil), with 0.42 MMT disappearance, 75% of which was destined for direct consumption, whereas the rest was used in the manufacture of margarine and mayonnaise. An analysis of internal demand by oil type in Argentina shows sunflower oil with 70% of the trade, followed by soybean (26%), and low volumes of corn and olive oils. Use of sunflower oil is widespread in this region. 

In our first experiment we decided to test the conversion of sunflower oil into biodiesel (16). Treatment of sunflower oil (1) with NaOMe in MeOH results in formation of a mixtme of fatty acid methyl esters (FAME), also known as biodiesel, and glycerol (2) (Figme 4.3). The reaction was performed with a six-fold molar excess of methanol with respect to sunflower oil at elevated temperatures (60°C) using a basic catalyst (NaOMe, 1% w/w with respect to sunflower oil). The CCS was equipped with a heating jacket to ensure isothermal conditions. The sunflower oil was preheated to 60°C and was pumped at 12.6 ml/min into one entrance of the CCS. Subsequently, a solution of NaOMe in MeOH was introduced through the other entrance at a flow rate of 3.1 ml per minute. After about 40 minutes, the system reaches steady state and the FAME containing some residual sunflower oil is coming... 

So, clustering techniques have been used for classification. Piepponen et al. applied a hierarchical cluster analysis (CLUSTAN) to the classification of food oils (groundnut, soya, sunflower and maize) by their fatty acid composition. The dendrogram of the distances shows four weU-separated clusters. Some suspect commercial samples of sunflower oil fall near the cluster of soya oils, so far from the clainud class that they cannot be consider i genuine. 

Carelli et al., on the other hand, elaborated a basic (rather than an acidic) fractionation scheme to collect the PL present in a chloroform solution of 50-150 mg of sunflower oil most triglycerides were recovered from a 500 mg of bonded diol SPE cartridge using 2.5 ml of chloroform, whereas PL were obtained by elution with 7 ml of methanol containing 0.5 ml/100 ml of a 25% ammonia solution (34). Using this procedure, the recovery of more than 98% pure soybean PE, PA, PI, and PC standards ranged from 94% to 107% at concentrations of 0.1, 0.6, and 1.0% in purified sunflower oil the coefficient of variation was typically of the order of magnitude of 5%. 

Biswas, S., K. Heindselmen, H. Wohltjen, et al. 2004. Differentiation of vegetable oils and determination of sunflower oil oxidation using a surface acoustic wave sensing device. Food Control 15 19-26. 

Although there are numerous publications on the effect of natural and synthetic antioxidants on the stability of oils and fats used as food and feed, until recently relatively little publicly available information was available on the effect of antioxidants on the oxidative stability of biodiesel. One of the earliest studies reporting of the effects of antioxidants on biodiesel was that of Du Plessis et aL (1985), which examined storage stability of sunflower oil methyl esters (SFME) at various temperatures for 90 d. Effects of air temperature, presence of light, addition of TBHQ (see Figure 1.1) and contact with steel were evaluated by analysis of free fatty acid content, PV, kinematic viscosity, anisidine value, and induction period. Addition of TBHQ delayed oxidation of samples stored at moderate temperatures (<30°C). In contrast, under unfavorable (50°C) conditions, TBHQ was ineffective. 

These figures are based on the use of sunflower-seed oil containing 5 7 per cent linoleic acid. With other oils, the yield will be proportionally larger or smaller, depending on the analysis of the oil. Approximate values for three oils may be calculated from the values given in Note 3 above. The yield from cotton-seed oil is 26-30 g. The checkers have brominated about nine times the amounts stated in these directions and have obtained proportionate yields. 

High-oleic sunflower and safflower oils By taking advantage of the wide range of natural sunflower and safflower varieties seed breeders have developed lines which, in place of the normal high levels of linoleic acid, have high levels of oleic acid (Table 2a). These are commercially available as Sunola ( 85% oleic acid) and Saffola ( 75% oleic acid) (49). They are used in Good-Fry (Section 2) and as an alternative to triolein in some enzymic processes (Section 8.5). A third type of sunflower oil (Nu-Sun) with an intermediate level of oleic acid (65%) and reduced levels of saturated acids is now available. 

In Russia, it was introduced by Peter I the Great, Czar between 1682 and 1725, who, having seen sunflowers in the Netherlands, took seeds to Russia. It was in Russia where the most important development took place in the use of sunflower as both food and oil source. The Russian Orthodox Church banned the consumption of several foods during Lent and Advent (periods of the religious calendar dedicated to fasting and penitence), including several sources of oil. As the ban did not include sunflower seeds, they were adopted as an oil source. 

Specific Heat and Combustion Heat The specific heat of sunflower oil at constant pressure is 2.197 J/kg °C (29). The energy content or combustion heat of an oil is a major parameter when used as an energy source. The gross heat contents of all vegetable oils are fairly close to each other. Ali and Hanna (30) report a gross heat content of regular sunflower oil of 39,575 kJ/kg, and Bhattacharyya and Reddy (31) a value of 39,486 kJ/kg. 

With a view to finding new industrial uses of vegetable oils, the saturated fatty acid content may also be increased. Three high stearic acid sunflower mutants, having as much as 28%, 15%, and 14% of stearic acid in the seed lipids have been... 

The procedures used for the extraction and processing of sunflower oil are broadly the same as for other seed oils. Focus will be made on those operations or details specific of the production of sunflower oil. Sunflower oil is usually extracted through pressing of seed and later extraction by solvent. The crude oil is usually subjected to traditional refining stages. Otherwise, cold-pressed sunflower oil is currently valued as a new extra virgin oil. 

Sunflower oil processing byproducts depend on the kind of refining, whether chemical or physical. The so-called deodistillate of chemical refining of sunflower oil can be used as feedstock for obtaining tocopherols and sterols. The tocopherol composition of sunflower oil (over 90% alpha-tocopherol and only a low proportion of the beta and gamma isomers) makes deodistillates of great value for industrial Vitamin E production. Increased importance has been placed on vegetal sterols because they were found to reduce the risk of cardiovascular disease. As a result, the demand for tocopherols and sterols was increased as food additives. 

Sunflower oil extracted from different types of hybrid may have different compositions. It is expected that the degree of unsaturation will influence the oxidative stability of sunflower oil markedly. AOM time measurements were used to determine the influence of oleic/linoleic ratio on the oxidative stability of sunflower oil (36). Oil samples extracted (refined and deodorized) from three progenies of cultivar Per-venets were analyzed, as well as other oil samples from different regions of the United States. The oleic acid content thus ranged from 18% to 89%, and the linoleic acid content decreased from 69% to 1 % the saturated fatty acid content was nearly constant. AOM values increased from 11 hours for the oil containing the least amount of oleic acid to 100 hours for that with the oleic acid highest content. These results show the importance of monounsaturated fatty acid content on the oxidative stabihty of sunflower oil. 

Frozen prefried foods are prepared before ingestion. Deep-fat frying is a most common cooking method for the manufacture of prefried foods. These foods are thus subjected to two different frying processes and a stage in a freezer prior to final cooking and consumption. Several studies have been performed to evaluate the oxidative resistance of sunflower oils when used in frying processes. 

Results show that regular sunflower oil rarely reaches a critical value of 25% of polar compounds in continuous frying processes with frequent turnover, indicating the suitability of sunflower oil for this use. However, use of this oil is recommended only for frying of crisp-type foods with short commercialization periods, ensuring their consumption before detectable levels of deterioration of the absorbed oil are reached (109). 

Mid-Oleic Sunflower Oil With the relatively recent appearance of mid-oleic sunflower oil, researchers have shown an interest in its use in frying processes. Abidi and Warner (120) used the three types of sunflower oil (regular, high, and mid-oleic) in the preparation of french fries, potato crisps, and fresh white corn tortilla chips. However, no general conclusions may be drawn regarding inherent stability as there is no indication of antioxidant type and concentration in the different oils. 

Other Applications Containing around 70% hnoleic acid, sunflower oil is a semidrying oil. Insofar as economically feasible, sunflower oil may replace soybean oil in the manufacture of resins for paint and press-ink formulations. Through epoxidation of sunflower oil, PVC stabihzers may be obtained, and dimerization would yield products that could be used for lubricant manufacture (41). 

The fact that the phospholipid composition of sunflower depends on the oil extraction method and the degumming treatment used to remove them explains the differences in the reported compositions in the literature. Phospholipid compositions of sunflower oil are shown by type in Table 20 (136, 139-141). The overall fatty acid composition also varies widely for the same reason. Cherry and Kramer (140) report composition ranges of 11.1-31.9% of palmitic acid, 3.0-7.9% stearic acid, 13.3-17.3% oleic acid, and 42.8-68.7% linoleic acid. 

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