Effects of Oil and Processing Conditions on Formation of Heterocyclic Amines and Polycyclic Aromatic Hydrocarbons in Pork Fiber

Abstract

Toxic compounds such as heterocyclic amines (HAs) and polycyclic aromatic hydrocarbons (PAHs) can be produced during food processing, especially meat products. This study aims to monitor the formation of HAs and PAHs in fried pork fiber, a common meat product in Taiwan, at different processing conditions. A total of six experimental groups, including raw pork tenderloin, dried pork filaments, sesame oil-stir-fried pork at 160 °C for 15 min, sesame oil-stir-fried pork at 200 °C for 6 min, lard-stir-fried pork at 160 °C for 15 min, and lard-stir-fried pork at 200 °C for 6 min, were prepared and analyzed for formation of HAs via UPLC-MS/MS and PAHs via GC-MS/MS in triplicate. Frying in sesame oil or lard showed a greater content of total HAs in fried pork fiber processed at 160 °C for 15 min than at 200 °C for 6 min. However, in the same heating conditions, pork fiber fried in sesame oil produced a higher level of total HAs than that fried in lard. Of the various HAs in fried pork fiber, both Harman and Norharman were generated in the highest amount. The precursors, including reducing sugar, amino acid, and creatine/creatinine, played a vital role in HAs formation in fried pork fiber. For total PAHs, the highest level was shown for pork fiber fried in lard at 200 °C/6 min, followed by frying in sesame oil at 200 °C/6 min and 160 °C/15 min, and in lard at 160 °C/15 min. Like HAs, at the same heating condition, a greater content of total PAHs was produced in pork fiber fried in sesame oil than in lard. Notably, the highly toxic benzo[a]pyrene was undetected in fried pork fiber. The PAH precursor benzaldehyde was shown to generate at a much higher level than 2-cyclohexene-1-one and trans,trans-2,4-decadienal in fried pork fiber, and it should play a more important role in PAH formation. Principal component analysis (PCA) also revealed that the formation mechanism of HAs and PAHs in fried pork fiber was different.

Analysis of Polycyclic Aromatic Hydrocarbons via GC-MS/MS and Heterocyclic Amines via UPLC-MS/MS in Crispy Pork Spareribs for Studying Their Formation during Frying

“…But for total PAHs, the highest level was shown for pork fiber fried in lard at 200 • C/6 min and the lowest level in lard at 160 • C/15 min [10]. Furthermore, under the same heating condition, the highly unsaturated sesame oil resulted in a higher content of total PAHs and HAs in pork fiber than the more saturated lard [10]. Consequently, the selection of an appropriate oil and processing condition is imperative to minimize the formation of HAs and PAHs in meat products during processing.…”

“…A method described by Lai et al [10] was used to analyze PAH precursors including benzaldehyde, cyclohexene, trans,trans 2,4-decadienal, 2-cyclohexene-1-one, and 4,4dimethyl-2-cyclohexene-1-one in raw, marinated and crispy pork spareribs via GC-MS/MS. In brief, a 0.5 g pork sample was poured into a 20 mL headspace vial containing 2.5 mL of water, followed by heating this mixture for 10 min at 65 • C, inserting the fiber head into the sample vial, heating for 20 min at 65 • C, and inserting into the Agilent GC-MS inlet for desorption in the injection port (260 • C) for 1 min.…”

“…The selective ion monitoring (SIM) mode with m/z at 68, 81, and 105 was used for the identification of 2-cyclohexene-1-one, trans,trans-2,4-decadienal, and benzaldehyde, respectively. Next, their contents were calculated from their respective standard curves [10]. Both cyclohexene and 4,4-dimethyl-2-cyclohexene-1-one were not quantified as they remained undetected in pork samples in GC-MS.…”

“…Interestingly, the addition of sugar was shown to reduce the formation of both PAHs and HAs during roasting, while soy sauce minimized the formation of several PAHs and promoted HA formation [2]. In another study dealing with the effects of oil type and processing condition on the formation of PAHs and HAs in pork fiber, frying in lard or sesame oil was shown to produce a higher content of total HAs at 160 • C for 15 min than at 200 • C for 6 min [10]. But for total PAHs, the highest level was shown for pork fiber fried in lard at 200 • C/6 min and the lowest level in lard at 160 • C/15 min [10].…”

“…In another study dealing with the effects of oil type and processing condition on the formation of PAHs and HAs in pork fiber, frying in lard or sesame oil was shown to produce a higher content of total HAs at 160 • C for 15 min than at 200 • C for 6 min [10]. But for total PAHs, the highest level was shown for pork fiber fried in lard at 200 • C/6 min and the lowest level in lard at 160 • C/15 min [10]. Furthermore, under the same heating condition, the highly unsaturated sesame oil resulted in a higher content of total PAHs and HAs in pork fiber than the more saturated lard [10].…”