Volatile compounds generated in corn oil stored at room temperature. Presence of toxic compounds

Abstract

Solid Phase Microextraction (SPME) followed by GC/MS was employed to study the headspace composition of corn oil (maize oil) samples stored at room temperature in closed receptacles with limited amounts of air for different periods of time. Samples with a high oxidation level showed the presence of typical secondary volatile oxidation compounds such as alkanals, 2-alkenals, 2,4-alkadienals, acids, alcohols, ketones, alkylfurans, and lactones. Aldehydes were the most numerous group; however, acids, which were fewer in number, showed the highest abundances. The high number of lactones detected is also noteworthy. In agreement with corn oil composition, those volatiles derived from linoleic acyl groups appeared in the highest abundances. The detection of two groups of toxic compounds, whose rise in concentration corresponded with the oxidation level of the samples, was remarkable. There were, on the one hand, alkylbenzenes and mono-and poly-cyclic aromatic hydrocarbons (PAHs) of low molecular weight, such as toluene, naphthalene, and fluorene. On the other hand, there were oxygenated a,b-unsaturated aldehydes like 4-hydroxy-2-nonenal, 4-oxo-2-nonenal, and 4,5-epoxy-2-decenal brought about by the oxidation of omega-6 polyunsaturated acyl groups (linoleic), and, in much lower proportions, 4-hydroxy-2-hexenal and 4,5-epoxy-2-heptenal coming from omega-3 ones (linolenic).Practical applications: The identification and quantification of such a great number of volatile compounds coming from corn oil can be very helpful for other researchers who study the degradation of this vegetable oil or other kinds with similar proportions of acyl groups.

Characterization of Aroma Volatiles in Camellia Seed Oils (<i>Camellia oleifera</i> Abel.) by HS-SPME/GC/MS and Electronic Nose Combined with Multivariate Analysis

“…Within the alcohols, 2-methyl-1-propanol was present in all oil samples. 1-octen-3-ol and pentanol were also found to be the main alcohols in corn oil stored at room temperature (Goicoechea et al, 2014). 2-Hexanol and 2-heptanol were only identified in CO18 with low concentration.…”

“…Of the volatiles produced by the breakdown of the alkoxy radicals, aldehydes are the most significant flavor compounds in Camellia seed oil, coincidently in olive oil and corn oil (Goicoechea & Guillén, 2014;Kesen et al, 2013). Especially, it was reported that C6 aldehydes and alcohols are the most abundant compounds and contribute significantly to the flavor of virgin olive oil (Cavalli et al, 2004).…”

Cold pressed versus refined winterized corn oils: quality, composition and aroma

“…These and others listed are similar to those determined in this study (Table 5). In another study (Goicoechea and Guillén, 2014), the volatile compounds generated in corn oils during storage at room temperature for various times (12-103 months) were measured. Usually oxidized samples included many secondary oxidation compounds including alkanals, 2-alkenals, 2,4-alkadienals, acids, alcohols, ketones, alkylfurans, lactones and a,b-unsaturated aldehydes.…”

Aplicação de planejamento fatorial na oxidação de óleos contendo diferentes tipos de ácidos graxos ômega 3

“…O excesso de calor promove a decomposição de hidroperóxidos e a ocorrência de reações adicionais, tais como polimerização, ciclização e cisão (Choe e Min, 2006;Laguerre et al, 2007a;Silva et al, 1999). Cada etapa da reação de oxidação apresenta energia de ativação específica, sendo maior na propagação (5)(6)(7)(8)(9)(10) kcal/mol) que na terminação (0-3 kcal/ mol) (Ragnarsson e Labuza, 1977 (Branco e Castro, 2011;Damodaran et al, 2010;Jurkovič et al, 2003;Karabulut, 2010;Lee et al, 1999;Shahidi e Wanasundara, 2011 …”

“…products that lower food quality and safety 2,[6][7][8][9][10][11] . The autoxidation of oils depends on the temperature, …”