Oilseed residues

Whey Cheese — Determination of Dry Matter Content (Reference Method), (d) ISO/R728-1969, Spices and Condiments — Determination of Total Ash ISO/R749-1968, Oilseed Residues — Determination of Total Ash ISO/R763-1971, Fruit and Vegetable Products — Determination of Ash Insoluble in Hydrochloric Acid ISO/R936-1969 Meat and Meat Products — Determination of Ash IS01575-... 

The oilseeds are generally rich sources of linoleic acid, and linseed is a particularly good source of a-linolenic acid. Pigs and poultry, which normally have considerable quantities of oilseed residues in their diets, will, therefore, receive an adequate supply of the essential fatty acids. 

Most oilseed residues are of tropical origin they include groundnut, cotton seed and soya bean. Some seeds such as castor bean yield residues are unsuitable for animal consumption because they contain toxic substances. 

Palm kernel meal generally refers to the product obtained after solvent extraction of palm oil from the oil palm, whereas palm kernel cake is produced by mechanical extraction. In practice, the term palm kernel meal is often used to describe either product. This food has a comparatively low content of protein, and the balance of amino acids is poor. The first limiting amino acid is lysine. The ratio of calcium to phosphorus is more favourable than in many other oilseed residues. The meal is dry and gritty, especially the solvent-extracted product, and is not readily eaten it is therefore used in mixtures with more acceptable foods. Attempts to use it mixed with molasses, as molassed palm kernel cake, have not been successful. It has a reputation for increasing the fat content of milk, and its chief use is for dairy cows. Palm kernel meal has been described as being balanced for milk production, but in fact it contains too high a proportion of protein to energy. 

International Standard Organization ISO 10632 2000 Oilseed residues—Simultaneous determination of oil and water contents—Method using pulsed nuclear magnetic resonance spectroscopy. 

Despite these negative attributes, there are opportunities for these phenolic compounds to be extracted using pure or aqueous solvents like ethanol to be further utilized as natural antioxidants. Studies showed that the extracts obtained from the oilseed residues displayed remarkable antioxidant activity, the extent of which depends on the type of residue and the solvent used for the extraction (Amarowicz et al 2000). Wanasundara et al. (1994) reported that the best antioxidant activity was exhibited by a fraction of canola meal phenolics that contained only 34 mg of phenolic compounds/g of sample. On the other hand, Amarowicz et al. (1996) observed that the antioxidant activity of ethanolic extracts of mustard correlated well with the total content of phenolic... 

Use of some oilseed proteins in foods is limited by flavor, color, and flatus effects. Raw soybeans, for example, taste grassy, beany, and bitter. Even after processing, residues of these flavors may limit the amounts of soybean proteins that can be added to a given food (87). The use of cottonseed and sunflower seed flours is restricted by the color imparted by gossypol and phenoHc acids, respectively. Flatus production by defatted soy flours has been attributed to raffinose and stachyose, which are removed by processing the flours into concentrates and isolates (88). 

After Flarvest. How do the memory effects shown by the other crops compare with those of winter wheat Winter wheat did not show a memory effect after one year, but oilseed rape does seem to do so. Researchers of the Agricultural Development and Advisory Service found that nitrate production by microbes in the soil after a rape crop increased with the amount of fertilizer given to the crop (R. Sylvester-Bradley, personal communication). One reason may lie in this crop s habit of shedding its leaves as harvest approaches, which means that the microbes in the soil get early access to these residues. This habit might contribute to the apparently smaller efficiency of this crop in using nitrogen fertilizer. The crop may be just as efficient as winter wheat at taking up the fertilizer but drops... 

This method published by MAFF (1993a) is not applicable to oilseeds or compound feeds containing milk powder. The sample is extracted with light petroleum and the residue then heated with 3 M HCl. This is filtered, washed, dried and re-extracted with light petroleum. 

Better and Davidsohn (23) reported that the susceptibility of proteins in oilseed presscaFe and solvent-extracted meal was strongly affected by heat treatment. Working with peanut and coconut presscake, they demonstrated that the stronger the heat treatment, the higher are the concentrations of pepsin required to make peptization more complete. This is an important fact to bear in mind when oilseed press or extraction residues are being used as raw materials for production of industrial protein. 

Extraction of fat by supercritical carbon dioxide was investigated as an important option for minimizing the expanded use of frequently flammable and carcinogenic solvents in food analysis. Unfortunately, the presence of moisture in foods has an adverse effect on the quantitative extraction of fat by supercritical fluid extraction (SEE). Hence, samples have to be lyophilized first. The total fat content of freeze-dried meat and oilseed samples was found to be comparable to values derived from Soxhlet-extracted samples (26). Besides, only small amounts of residual lipids could be recovered by an additional extraction of the SFE-extracted matrix by the Bligh and Dyer solvent extraction procedure. As far as the minor constituents are concerned, it was found that the extraction recovery ranged from 99% for PC to 88% for PA. Hence, Snyder et al. concluded that SFE can be used as a rapid, automated method to obtain total fat, including total phospholipids, from foods (26). 

Many solvents have been proposed for extracting oilseeds, but later found ineffective others were used for a period, but disallowed because of health concerns about residues in food and feed products, or worker exposure.93 All Extraction solvents approved... 

Solvent extraction. The press cake emerging from a screw press still retains 3 to 15 percent of residual oil. More complete extraction is done by solvent extraction of the residues obtained from mechanical pressing. The greater efficiency obtained in the solvent extraction process encouraged the industry for direct application to oilseeds. In the United States and Europe, continuous extractor units are used in which fresh seed flakes are added continuously and are subjected to a counterflow of solvent by which intimate contact is achieved between the seeds and solvent. The common solvent for edible oil is commercial hexane or heptane, commonly known as petroleum ethers, boiling in the range of 146 to 156°F (63.3 to 68.9°C). After extraction, maximum solvent recovery is necessary for economical operation. The solvent is recovered by distillation and is reused. The extraction oil is mixed with prepress oil for refining. The extracted meals contain less than 1 percent of residual oil. 

The amino acid composition of sunflower meal is generally balanced. The energy content of sunflower meal compares favorably with other oilseed meals. The energy value of a sunflower meal increases with increasing residual oil content and a reduction of the fiber content. Sunflower meal is also valuable as a calcium and phosphorous source and a good source of hydrosoluble B complex vitamins. 

Mechanically Extracted Meals. Solvent extracted oilseed meals typically contain less than 1.5% residual fat unless the gums (hydrated phosphatides) or soapstock have been added back to the meal before the desolventizer-toaster or meal dryer. Mechanically extracted (expeller or screw-pressed) meals can contain 4—9% oil, which can be a significant calorie source in animal feeds. Fat contents of extracted meals are not part of the definition, although typical analyses are shown below. 

The major lecithin sold domestically in commercial quantities is extracted from soybeans. Com and sunflower seed lecithins are available in limited amounts. Canola is being reviewed as a lecithin source in countries that do not grow significant quantities of soybeans. Lecithins may be added to feeds in cmde or refined forms, remain as residuals in solvent- or mechanical-extracted oilseed meals, be returned to oilseed meals as extracted gums or soapstocks at combined solvent extraction-oil refinery operations, or simply be native to an oilseed fed whole. 

The energy content of sunflower meal compares favorably with that of other oilseed meals and increases as the residual oil content increases and as the fiber content decreases. Sunflower meal also compares favorably with other oilseed meals as a source of calcium and phosphorus (36) and is an excellent source of water-soluble B-complex vitamins, namely nicotinic acid, thiamine, pantothenic acid, riboflavin, and biotin. 

Several processors attempted to use a mixed media (sand, anthracite) filter to remove residual oils. This technology was adopted from petroleum waste applications however, it did not function well in oilseeds applications, because of an inability to backwash these units caused by the highly viscous nature of these oils at ambient temperature. 

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