Minor Constituents in Canola Oil Processed by Traditional and Minimal Refining Methods

Abstract

The minimal refining method described in the present study made it possible to neutralize crude canola oil with Ca(OH) 2 , MgO, and Na 2 SiO 3 as alternatives to NaOH. After citric acid degumming, about 98 % of the phosphorous content was removed from crude oil. The free fatty acid content after minimal neutralization with Ca(OH) 2 decreased from 0.50 to 0.03 %. Other quality parameters, such as peroxide value, anisidine value, and chlorophyll content, after traditional and minimal neutralization were within industrial acceptable levels. The use of Trisyl silica and Magnesol R60 made it feasible to remove the hot-water washing step and decreased the amount of residual soap to \10 mg/kg oil. There were no significant changes in chemical characteristics of canola oil after using wet and dry bleaching methods. During traditional neutralization, the total tocopherol loss was 19.6 %, while minimal refining with Ca(OH) 2 , MgO, and Na 2 SiO 3 resulted in 7.0, 2.6, and 0.9 % reductions in total tocopherols. Traditional refining removed 23.6 % of total free sterols, while after minimal refining free sterols content did not change. Both traditional and minimal refining resulted in almost complete removal of polyphenols from canola oil. Total phytosterols and tocopherols in two cold-pressed canola oils were 774 and 836 mg/100 g, and 366 and 354 mg/kg, respectively. The minimal refining method described in the present study was a new practical approach to remove undesirable components from crude canola oil meeting commercial refining standards while preserving more healthy minor components.

Optimizing refining temperatures to reduce the loss of essential fatty acids and bioactive compounds in tea seed oil

“…Refining has much effect on the composition and final quality of refined sunflower oil (Ortega-García et al, 2006), rapeseed oil (Zacchi and Eggers, 2008), olive oil (Essid et al, 2006), soybean oil and canola oil (Farhoosh et al, 2009). For example, reduce deodorization temperature to 150 • C can significantly increase the composition quality of the refined soybean oil or canola oil because of the lower temperature (Wang et al, 2002;Ghazani et al, 2013), which is consistent with our results.…”

Effect of refining process on antioxidant capacity, total phenolics and prooxidants contents in rapeseed oils

“…The refining processes of crude rapeseed oil ensure a reduction of prooxidants metals and other elements (Ca, Mg, Na, K ions) in refined oil (Hafidi, Pioch, & Ajana, 2005;Van Hoed, Ali, Slah, & Verh e, 2010). However, during these processes, a large amounts of the micronutrients and antioxidants such as, polyphenols, tocopherols, sterols, carotenoids are lost, which thus reduce substantially the nutritional value and quality of rapeseed oils (Ghazani, García-Llatas, & Marangoni, 2013;Szydłowska-Czerniak, 2013). The deodorization step caused the highest (7e90%) losses of tocopherols in rapeseed oils, while neutralization and bleaching decreased the content of these antioxidants only by 0.5e19.6% (Chen, Thiyam-Hollander, Barthet, & Aachary, 2014;Ghazani et al, 2013;Gogolewski, Nogala-Kałucka, & Szeliga, 2000;Kreps et al, 2014;Szydłowska-Czerniak, Karlovits, Dianoczki, Recseg, & Szłyk, 2008;Van Hoed et al, 2010;Zacchi & Eggers, 2008).…”

“…However, during these processes, a large amounts of the micronutrients and antioxidants such as, polyphenols, tocopherols, sterols, carotenoids are lost, which thus reduce substantially the nutritional value and quality of rapeseed oils (Ghazani, García-Llatas, & Marangoni, 2013;Szydłowska-Czerniak, 2013). The deodorization step caused the highest (7e90%) losses of tocopherols in rapeseed oils, while neutralization and bleaching decreased the content of these antioxidants only by 0.5e19.6% (Chen, Thiyam-Hollander, Barthet, & Aachary, 2014;Ghazani et al, 2013;Gogolewski, Nogala-Kałucka, & Szeliga, 2000;Kreps et al, 2014;Szydłowska-Czerniak, Karlovits, Dianoczki, Recseg, & Szłyk, 2008;Van Hoed et al, 2010;Zacchi & Eggers, 2008). However the reduction of total and individual sterols in rapeseed oils after complete refining process was approximately 5e70% (Ferrari, Esteves, Mukherjee, & Schulte, 1997;Ghazani et al, 2013;Hafidi, Pioch, & Ajana, 2005;Van Hoed et al, 2010;Zacchi & Eggers, 2008).…”

Effect of Refining Process on the Quality Characteristics of Soybean and Cotton seed Oils

“…FFA determination is particularly important for industrial purposes since FFA can modify the organoleptic or physicochemical properties of oil. FFA can act as pro-oxidants in vegetable oils and result in an undesirable taste and flavor (Ghazani et al, 2013). Thus, one of the main objectives of oil refining is to remove FFA from crude oil.…”

“…During the industrial production of vegetable oils and fats by crushing or solvent extraction, various kinds of minor constituents such as dirt, moisture, gums, waxes, color pigments, flavoring substances, phosphates, carbohydrates, protein, pesticide residues, odoriferous materials, trace metals, free fatty acids and the possible residual content of the solvent used for the extraction process are incorporated into triglycerides and may cause the oil to be darkened, foamed, smoked, precipitated, develop off-flavours, decrease thermal and oxidative stability, and increase oil loss (Ghazani et al, 2013). The term crude…”