Heptane as a less toxic option than hexane for the separation of vitamin E from food products using normal phase HPLC

Abstract

The term 'vitamin E' refers to a group of eight vitamers (alpha-, beta-, gamma-, delta-tocopherols and tocotrienols). Its primary role is thought to be as an antioxidant commonly added to a variety of foods, e.g. bakery products. High-Performance Liquid Chromatography (HPLC) procedures are used for the separation and analysis of these tocopherols and tocotrienols in foods. The use of a normal phase column is the preferred approach in such methods, with hexane almost universally utilised as the mobile phase. However there is increasing concern regarding the toxicity of hexane. Here we evaluate the use of heptane as a replacement for hexane in HPLC based vitamin E analysis. The two solvents were compared using samples of bread fortified with palm oil (as a source of vitamin E). Accelerated solvent extraction procedure followed by HPLC showed the effective separation of the E vitamers in a variety of bread samples using both solvents. It is concluded that heptane provides effective separation and quantification of the E vitamers found in cereals and cereal products while also reducing operator risk.

Effect of Fermentation and Oil Incorporation on the Retention of E Vitamers During Breadmaking

“…Baking was then performed at 230°C for 10 min, followed by a further 15 min at 200°C, as previously described (Buddrick et al 2013). The resulting dough was placed into bread tins for a final proofing stage of 37°C for 45 min.…”

“…Following baking, samples were allowed to cool to room temperature, sliced, and frozen at -40°C with a freeze dryer (VirTis, SP Industries, Gardiner, NY, U.S.A.) to obtain lowmoisture-content samples for further analysis (Buddrick et al 2013). Following baking, samples were allowed to cool to room temperature, sliced, and frozen at -40°C with a freeze dryer (VirTis, SP Industries, Gardiner, NY, U.S.A.) to obtain lowmoisture-content samples for further analysis (Buddrick et al 2013).…”

“…We have recently reported on procedures for the analysis of vitamin E by normal-phase HPLC with heptane rather than hexane for the separation of the eight vitamer forms in wheat bread (Buddrick et al 2013); similar protocols were used in the present study, and the method is outlined here.…”

“…The resulting dough was placed into bread tins for a final proofing stage of 37°C for 45 min. Baking was then performed at 230°C for 10 min, followed by a further 15 min at 200°C, as previously described (Buddrick et al 2013). All breads (wheat and rye) were prepared in triplicate.…”

Current Research Developments on the Processing and Improvement of the Nutritional Quality of Rapeseed (Brassica napus L.)

“…n ‐Hexane, which has a comparatively low boiling point (69 °C), is a commonly‐used petroleum‐based solvent with substantial selectivity to oils and low latent heat of vaporization (330 kJ kg −1 ), which promotes evaporation, effective extraction, and limited energy cost. Notwithstanding, long‐term exposure to commercial‐grade n ‐hexane can provoke dysfunctions of the central nervous system and fertility disorders . However, there are still many restrictions before considering any industrial application of new solvents to extract edible oils.…”