Release mechanism between sarcoplasmic protein-bound and free heterocyclic amines and the effects of dietary additives using an in-vitro digestion model

Investigation on synergistic inhibition of protein-bound heterocyclic amines in sarcoplasmic and myofibrillar model systems by amino acid combinations

The inhibition of amino acids on the formation of protein-bound HAs was assessed in both model systems and roast beef patties, and the synergism between these amino acids was also investigated. The amino acids can promote the formation of protein-bound HAs at low addition amount, and the total content of protein-bound HAs increased from 444.05 ± 4.98 ng/g of the control group to 517.36 ± 16.51 ng/g when 0.05 % cysteine was added. Amino acid combinations exhibited stable inhibitory effects, with the maximum inhibitory rate of 64 % in the treatment with histidine-proline combination (1:4). The synergistic inhibition may be caused by simultaneously scavenging intermediates and competing for the binding sites of muscle proteins, and the reaction with protein-bound HAs to form adduct can serve as supporting factors to co-mitigate the promotion in protein-bound HAs from increased protein solubility. These findings proposed the potential mitigation strategies against protein-bound HAs formation.

Effects of seasoning addition and cooking conditions on the formation of free and protein-bound heterocyclic amines and advanced glycation end products in braised lamb

The accumulation of heterocyclic amines (HAs) and advanced glycation end products (AGEs) in thermally processed meats has been arising safety concerns. The effects of cooking conditions and seasoning addition on the formation of HAs and AGEs in Chinese traditional braised lamb were investigated by UPLC-MS/MS analysis. Soy sauce significantly increased the formation of HAs and AGEs, among which light soy sauce had the greatest promoting effect (69.45-15300.62 %). Conversely, spices inhibited HAs and AGEs formation, the inhibition rate of free HAs and AGEs reached 22.06-34.72 % when using 70 % ethanol extract. Hot blanching treatment and adding soy sauce and spices at a later stage could significantly suppress HAs and AGEs production. Flavonoids, including galangin, hesperidin, narirutin, etc., were identified as key effectors in spices. These findings help to promote awareness of the formation of HAs and AGEs in braised lamb and provide valuable insights for optimizing processing techniques to minimize their production.

The impact of temperature-controlled smoldering smoking on polycyclic aromatic hydrocarbons and heterocyclic amines contents in Frankfurter-type sausages

The impact of temperature-controlled smoldering smoking conditions on the accumulations of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HAs) in Frankfurter-type sausages was investigated. Depending on the temperature, smoking can be divided into two phases: an unstable pyrolysis stage (≈ 200 s) and a stable pyrolysis stage (>200 s), which had different effects on hazardous substances contents. The unstable pyrolysis stage, which contributed 66.9 ∼ 89.6% of PAH accumulations by comparing with sausages smoked for 15 min, has significant impact on high PAH residues. By contrast, the contents of HAs showed steady increase trends with smoking time. Few types of free-HAs with low concentrations (3.05 ∼ 22.9 ng/g DW), but more types of bound-HAs with much higher levels (10.8 ∼ 396 ng/g DW) were found. In addition, the formation of some HAs followed the first-order reaction model. However, the detailed formation mechanisms of PAHs and HAs under temperature-controlled smoldering smoking conditions remain to be studied.

Formation of Carcinogens in Processed Meat and Its Measurement with the Usage of Artificial Digestion—A Review

Meat is a rich source of various nutrients. However, it needs processing before consumption, what in turn generates formation of carcinogenic compounds, i.a., polycyclic aromatic hydrocarbons (PAH), nitrosamines (NOCs), and the most mutagenic heterocyclic aromatic amines (HAAs). It was widely found that many factors affect the content of carcinogens in processed meat. However, it has recently been discovered that after digestion free HAAs are released, which are not detectable before enzymatic treatment. It was established that the highest percentage of carcinogens is released in the small intestine and that its amount can be increased up to 6.6-fold. The change in free HAAs content in analyzed samples was dependent on many factors such as meat type, doneness, particle size of meat, and the enzyme concentration used for digestion. In turn, introduction of bacteria naturally occurring in the human digestive tract into the model significantly decreases total amount of HAAs. Contrary, the addition of food ingredients rich in polyphenols, fiber, and water (pepper powder, onions, apples) increases free HAAs’ release up to 56.06%. Results suggests that in vitro digestion should be an integral step of sample preparation. Artificial digestion introduced before chromatographic analysis will allow to estimate accurately the content of carcinogens in processed meat.