Inhibitory Effect of Rosa rugosa Tea Extract on the Formation of Heterocyclic Amines in Meat Patties at Different Temperatures
In previous studies, heterocyclic amines (HCAs) have been identified as carcinogenic and a risk factor for human cancer. Therefore, the present study was designed to identify bioactive natural products capable of controlling the formation of HCAs during cooking. For this purpose we have evaluated the effect of Rosa rugosa tea extract (RTE) on the formation of HCAs in ground beef patties fried at 160˝C or 220˝C. RTE is rich in phenolic compounds and capable of inhibiting the formation of free
... ormation of free radicals. The pyrido[3,4-b]indole (norharman) and 1-methyl-9H-pyrido[3,4-b]indole (harman) contents were significantly (p < 0.05) decreased in RTE-treated patties at 220˝C. 9H-3-Amino-1-methyl-5H-pyrido[4,3-b]indole acetate (Trp-P-2) and 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole acetate (Trp-P-1) were not detected at 160˝C and were statistically (p < 0.01) reduced at 220˝C compared to the control. RTE remarkably inhibited the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP) at 220˝C (p < 0.001) and at 160˝C (p < 0.05). 2-Amino-9H-pyrido[2,3-b]indole (AαC) and 2-amino-3-methyl-9H-pyrido[2,3-b]-indole (MeAαC) were only detected in the control group at 160˝C but were comparatively (p > 0.05) similar in the control and treated groups at 220˝C. 2-Amino-3-methylimidazo[4,5-f ]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f ]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f ]quinoxaline (MeIQx), and 2-amino-3,4,8-trimethylimidazo[4,5-f ]quinoxaline (4,8-DiMeIQx) were not detected in any sample. Total HCAs were positively correlated with cooking loss. In the RTE-treated groups, 75% of the total HCAs were decreased at 160˝C and 46% at 220˝C, suggesting that RTE is effective at both temperatures and can be used during cooking at high temperatures to lessen the amount of HCAs formed. Molecules 2016, 21, 173 2 of 14 condensate and diesel-exhaust particles, but the most important source of exposure to HCAs occurs from high temperature cooked meat products  . Moreover, HCAs produced even during common household cooking procedures  due to high temperature, subsequently result in more accumulation of HCA content  . Basically HCAs belong to a class of structurally similar compounds having three fused aromatic rings possessing at least one nitrogen atom, one exocyclic amino group and up to four methyl groups  . Based on this chemical constitution, HCAs can be classified into two groups; the aminocarbolines and the aminoimidazoazaarenes. Carbolines are further subdivided into α, β and γ-carbolines. Aminocarbolines or pyrolytic HCAs are formed at higher temperatures (more than 250˝C). Harman and norharman are aminocarbolines known as "co-mutagens" because they do not show mutagenicity to Salmonella serovar typhimurium [9,10]. Another group called "thermic" HCAs are formed at temperatures between 150˝C and 250˝C [11, 12] . The International Agency for Research on Cancer (IARC) has reported 2-amino-3,8-dimethylimidazo[4,5-f ]quinoxaline (MeIQx), 2-amino-3,4dimethylimidazo[4,5-f ]quinoline (MeIQ), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) as possible human carcinogens and 2-amino-3-methylimidazo[4,5-f ]quinoline (IQ) as a probable human carcinogen and has recommended that exposure to these compounds be minimized  . Therefore, concentrations of HCAs in meat products should be minimized by applying different approaches. Antioxidants are well known for the reduction of HCAs in cooked meat. However, in the common household cooking of meat, commercial antioxidants are not very easy to apply, and synthetic antioxidants such as butylated hydroxytoluene and butylated hydroxyanisole have already been banned in many countries; consequently, natural antioxidants have been receiving much attention in this context. Roses are known as edible and have been used in their fresh form or in processed products such as confectioneries and beverages. Rosa rugosa is a natural antioxidant plant commonly used in the manufacture of wines, teas, juices and jams  . High antioxidant activity and phenolic compound levels were observed in Rosa rugosa by Altıner and Kılıçgün  . Many polyphenolic compounds including gallic acid, catechin, epicatechin, epigallocatechin gallate, epicatechin gallate, quercetin, benzoic acid, quercetin glucoside, tannin and kaempferol were previously reported in Rosa rugosa tea  , and polyphenolic compounds may reduce the formation of HCAs in cooked meat. Therefore, the present study was conceived. Recently, Rosa rugosa tea has attracted the attention of many researchers, who have determined its potential health benefits, which are expected to enhance the applications of Rosa rugosa tea in functional food products. To the best of our knowledge, the application of Rosa rugosa tea in meat products has not yet been reported in the literature, therefore, the objectives of the present study were to evaluate the total phenolic compounds, total antioxidant capacity and radical scavenging activity of Rosa rugosa tea extract and the effect of Rosa rugosa tea extract on the formation of HCAs and certain quality characteristics of ground beef patties fried at 160˝C and 220˝C.