The sterol hydrocarbons in edible oils

Abstract

Since 1957 we have published the results of our research on the transformation of sterols in vegetable oils due the industrial treatment. During bleaching sterol hydrocarbons are formed which are partly removed due the deodorising. Hardening transforms them partly into other steroids. Thus the sterol hydrocarbons are also present in margarine. We have found that the content of those compounds amounted to a quantity of 0.023%. The apolar steroids are highly sensitive to the conditions of autoxidation. All margarines and edible oils contain not only steroid hydrocarbons but also the products of their oxidation and hydrogenation.

Studies on phytosterol oxides. II: Content in some vegetable oils and in French fries prepared in these oils

“…A few studies in the early 1960s and 1970s, however, demonstrated the presence of 7-hydroxysito-and 7-ketositosterol in crude and refined vegetable oils (6,7). It was demonstrated that 7-ketositosterol was generated from 7-hydroxysitosterol mainly during bleaching processes (7). However, only qualitative data, based on TLC and spectroscopic analyses, were presented in those reports (6,7).…”

“…It was demonstrated that 7-ketositosterol was generated from 7-hydroxysitosterol mainly during bleaching processes (7). However, only qualitative data, based on TLC and spectroscopic analyses, were presented in those reports (6,7). A recent study demonstrated that crude soybean oil, freshly refined soybean oil, refined soybean oil stored at 4°C for one year, and freshly opened olive oil samples did not contain any sterol oxidation products, at a detection limit of 0.2 ppm.…”

“…A few studies have shown that crude rapeseed oil, as well as rapeseed and soybean oils during industrial refining, contain 7-hydroxysitosterol and 7-ketositosterol. However, these studies mainly demonstrated qualitative data on these oxides (6,7). Several model studies on the oxidation of sitosterol, and one study with stigmasterol in different fats and oils media, have been published (8)(9)(10)(11).…”

The Effect of processing on the content and composition of free sterols and sterol esters in soybean oil

“…Studies on sterol esters of long chain fatty acids showed that they were deacylated during treatment with bleaching earth, and products similar to those obtained from free sterols were formed (11). Furthermore, the quantity of nonpolar steroids formed during treatment with bleaching earth was shown to be proportional to the quantity of esterified sterols (6), which more easily undergo dehydration than the free sterols. In the referred study, comparison between sunflower, with a relatively small ,content, and rapeseed oil, with larger content of sterol esters, was carried out.…”

“…Sterols are removed during the refining processes. This makes the soapstock and the deodorizer distillate a source for sterols as raw materials in chemical industries (4)(5)(6)(7). Sterols are generally regarded as heat-stable as well as odorless and tasteless (8), making them of less interest as regarding the Ipresent address Food Technology Division, ALFA-LAVAL, S-14700 Tumba, Sweden.…”