Natural Variations of Precursors in Pig Meat Affect the Yield of Heterocyclic Amines − Effects of RN Genotype, Feeding Regime, and Sex

Abstract

Pig meat shows natural variations in the concentrations of precursors of heterocyclic amines (HCAs), which may affect formation of HCAs in cooked pig meat. To study this, 26 pigs with an inherent genetic variation (carriers and noncarriers of the RN(-) allele) were subjected to different feeding regimes (conventional feed compared with feed composed according to organic standards). In addition, the effect of sex (castrated males or females) was considered when assessing chemical and technological meat quality parameters. Concentrations of precursors of HCAs, i.e., creatine, residual glycogen, dipeptides, and free amino acids, were analyzed in the raw meat, and the levels of some HCAs (4,8-DiMeIQx, MeIQx, PhIP, harman, and norharman) were then determined in fried meat patties prepared from these pigs. The RN genotype most affected technological meat quality parameters and the level of precursors of HCAs, especially the level of residual glycogen, where carriers of the RN(-) allele showed levels four times as high as those of noncarriers (75.3 +/- 2.6 compared with 17.2 +/- 2.4 micromol/g meat, least-squares means +/- SE). The increased level of residual glycogen resulted in about 50% lower amounts of total mutagenic HCAs in cooked meat compared with cooked meat from normal pigs. Fried meat from carriers of the RN(-) allele obtained darker crust color than meat from noncarriers. Feeding regime and sex did not significantly affect the chemical composition of the meat or the formation of HCAs.

Dietary intake of heterocyclic amines in relation to socio-economic, lifestyle and other dietary factors: estimates in a Swedish population

“…A linear relationship between HCA content and the degree of browning is, however, not evident 40 . For instance, some recent studies have indicated that background factors, such as genetic variations in pigs, may influence the appearance and the colour of fried meat 41,42 , and colour photographs may therefore be misleading when estimating HCA intake. Several case-control and cohort studies have investigated the association between meat consumption and risk of cancer.…”

Heterocyclic aromatic amines in domestically prepared chicken and fish from Singapore Chinese households

“…Several studies have examined other factors that might affect HAA formation, such as pretreatment with marinades (Tikkanen et al 1996;Salmon et al 1997;Nerurkar et al 1999), addition of vitamins, herbs or spices (Murkovic et al 1998;Balogh et al 2000), combination of fruit or vegetables with ground meat (Britt et al 1998;Kato et al 1998), and use of techniques such as microwave cooking (Felton et al 1994;Chiu et al 1998), convection roasting , or frequent turning of meat . Inherent characteristics of meats, such as animal source (Vikse and Joner 1993;Pais et al 1999;Olsson et al 2002), and fat and water content (Johansson and Jägerstad 1994) have also been considered, relative to the HAA levels that form in them when cooked.…”

Colour photographs for estimation of heterocyclic amine intake from fried pork chops of different RN genotypes indicate large variations

“…The RN mutation affects several of the precursors for the formation of HCAs, and due to hyper-accumulation of glycogen in glycolytic muscles, meat from carriers of the RN À allele exhibits markedly higher reducing sugar levels, here expressed as residual glycogen, compared to the normal meat of non-carriers (Estrade, Vignon, Rock, & Monin, 1993;Fernandez, Tornberg, Naveau, Talmant, & Monin, 1992;Lundstr€ om, Andersson, & Hansson, 1996). Further, we have found that the level of creatine and some free amino acids in the meat are affected by the RN genotype of the pigs (Olsson et al, 2002).…”

“…For pig meat, this was exemplified by Skog (2002), who showed that varying levels of glucose in meat of the same species may affect the degree of surface browning and that the concentration of HCAs may not necessarily be higher in cooked meat with a darker surface. We have shown that pig meat of different genotypes (the dominant RN À mutation) through a marked variation in glycogen levels, may give rise not only to varying concentrations of HCAs but also degree of browning when fried under identical conditions (Olsson, Solyakov, Skog, Lundstr€ om, & J€ agerstad, 2002). In that study, a subjective scoring of surface browning correlated negatively with the level of HCA.…”

“…In a study where meat from a total of 26 animals were included, the same tendency, however not as marked, showed that about half the amount of mutagenic HCAs were formed in cooked meat of carriers compared to non-carriers of the RN À allele (Olsson et al, 2002). The high residual glycogen content of the RN meat most probably explains the reduced HCA levels.…”