## 3 Results and Discussion
### Considerations of General Health Risks Posed by Human Exposure to Aldehydic LOPs
#### 3.7.1 Overview of Health Risks
[77] reported that peroxididsised linoleicoylglycerol-derived HNE was readily detectable in French fry samples collected from n = 6 fast-food restaurants at concentrations of 8-32 \(\mu\)g/100 g portions (equivalent to 0.51-2.05 \(\mu\)mol kg\({}^{-1}\), and 0.9-4.9 \(\mu\)g/g of extracted lipid). Therefore, for a very large (adult) serving of European fried potato chips of mass 400 g, this represents between 32 and 128 \(\mu\)g of HNE. However, an important consideration is that this aldehyde, which is PUFA- and _not_ MUFA-derived, is generally detectable in thermally-stressed PUFA-containing oils at much lower levels than those of similarly health-threatening _trans_-2-alkenals and alka-(_trans_,_trans_)-2,4-dienals. From our laboratory, typical estimates of total 4-hydroxy-_trans_-2-alkenals expressed as apercentage of the total \(\alpha\),\(\beta\)-unsaturated aldehyde content remaining in oils when heated at 180 \({}^{\circ}\)C for a 90 min duration are only ca. <2 and 7% for extra-virgin olive and sunflower oils, respectively (data not shown). Mean concentrations of total _trans_-2-alkenals, alka-(_trans.trans_)-2,4-dienals and _n_-alkanals in potato chip samples purchased from fast-food restaurants, which were found to be 121, 157 and 126 \(\upmu\)mol kg\({}^{-1}\), respectively [13], are certainly substantially greater than those of 4-HNE. Moreover, these levels are also markedly higher than trace levels of acrylamide found in French fry and potato snack foods, which are predominantly lower than the regulatory limit value set by the European Commission (EC) for ready-to-eat fries, i.e., 0.6 ppm (equivalent to only 8.4 \(\upmu\)mol/kg) [78], and which rarely exceed 1 ppm (equivalent to 14.1 \(\upmu\)mol kg\({}^{-1}\)). Acrylamide is known to exert toxicological actions on the nervous system and fertility, and is also potentially carcinogenic [79]. A further important point is that acrolein may serve as a significant acrylamide source when asparagine-rich foods are deep-fried in PUFA-rich oils [80]. In this context, it is therefore important to note that recently the Australian Government Department of Health specified that the acceptable daily intake (ADI) value for acrolein (which can be considered to be the lowest homologue \(\alpha\),\(\beta\)-unsaturated aldehyde, of a similar toxicity to other \(\alpha\),\(\beta\)-unsaturated aldehyde LOPs), i.e., that which is considered to be a level of intake of this molecule that can be ingested daily over an entire lifetime without any appreciable risk to health, to be only 0.5 \(\upmu\)g per kg of body weight (BW), i.e., a total of only 35 \(\upmu\)g for an assumed (average) human BW of 70 kg [81]. The corresponding value set by the World Health Organisation (WHO) [82] is 7.5 \(\upmu\)g per kg BW, i.e., 525 \(\upmu\)g for an average BW of 70 kg (WHO, 2002). This consideration alone is a very worrying prospect, not least because this value represents the human intake of _only one_ of many toxic/carcinogenic aldehydes available in fried meals. In [13], we estimated the mean \(\pm\) SEM acrolein molecular mass-normalised contents of the most predominant _n_-alkanals, _trans_-2-alkenals and alka-(_trans.trans_)-2,4-dienals contained within a typical 154 g 'large' portion of European fried potato chips obtained from fast-food restaurants (i.e., those arising from oxidation of the highest content PUFA in a PUFA-predominant CFO such as corn or sunflower oils, specifically linoleic acid as linoleicylglycerols), which were found to be as high as 1.5 \(\pm\) 0.2 (2.6 \(\pm\) 0.4), 1.1 \(\pm\) 0.2 (2.5 \(\pm\) 0.4) and 1.1 \(\pm\) 0.2 (2.9 \(\pm\) 0.4) mg, respectively (actual estimated values are in brackets) for _n_-hexenal, _trans_-2-octenal and deca-(_trans.trans_)-2,4-dienals, contents substantially greater or greater than the recommended ADI values documented by the AGDH and the WHO, respectively [83]. It should also be noted that these estimates are for only a single serving of this very commonly consumed fried food source.