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.

Epidemiological characteristics and factors affecting blood pressure of migratory hypertensive population in Hainan Province A study of 180 cases / 中国热带医学

@#Abstract: Objective　To understand the epidemiological characteristics of the migratory bird population with hypertension in Hainan and to provide a basis for the health management of the migratory bird population. Methods　One hundred and eighty migratory birds with hypertension who had lived in in the Mangrove Bay community of Chengmai, Hainan for 3 months or more were selected as the study population. Demographic data, including gender, age, ethnicity, occupation, medication use, family history of hypertension, hometown living environment, Hainan living environment (presence of water area and greenbelt around the residence, type of water area and greenbelt), smoking and alcohol consumption, and height and weight were collected by questionnaire and physical examination to investigate the epidemiological characteristics of the study subjects, and unconditional dichotomous logistic regression analysis was used to identify factors affecting the reduction of blood pressure among the hypertensive migratory bird population before and after taking medication in Hainan. Results　A total of 180 study subjects were included, including 77 (42.8%) males and 103 (57.2%) females, with 78 (43.3%) subjects aged ≤65. The hypertension levels were: 87 (48.3%) had normal high blood pressure, 56 (31.1%) had grade 1 hypertension and 37 (20.6%) had grade 2 hypertension. The higher the blood pressure classification, the lower the percentage of migratory individuals whose blood pressure dropped during their stay in Hainan. Age, hypertension classification, dietary habits, living environment, body mass index (BMI), and alcohol consumption were associated with a decrease in blood pressure during Hainan among the study participants who took hypertension medication regularly. Salty diet (OR=2.778, 95%CI:1.070-7.213, P=0.036) and alcohol consumption (OR=2.686, 95%CI:1.042-6.925, P=0.041) were unfavorable factors for lower diastolic blood pressure before taking medication; overweight (OR=3.487, 95%CI:1.306-9.310, P=0.013) was an unfavorable factor in the reduction of diastolic blood pressure after taking medication. Conclusion　The blood pressure reduction is more significant in migratory individuals in migratory individuals under 65 years old, with a light diet, no alcohol consumption and normal BMI. Environmental factors, age, dietary habits and lifestyle are the main causes of blood pressure, which can provide a reference basis for the health management of the migratory birds with hypertension in Hainan.

Release profiles of beef myofibril protein-bound heterocyclic amines and effects of dietary components on in vitro digestion.

The release profiles of protein-bound heterocyclic amines (HAs) in beef myofibril protein (MP) model systems were investigated after different enzyme dosage or stages of digestion were simulated in vitro. The effects of co-digestion of pepper, apple, and onion with bound HAs on the release rate of bound HAs were also explored. The results showed that, at a constant ratio of substrate to enzyme, the bound HAs were not completely converted into free HAs. Most bound HAs were enzymatically released after intestinal digestion, resulting in a significant increase of free HAs. ß-Carbolines were more easily hydrolyzed compared with other HAs. Pepper, apple, and onion promoted the release of bound HAs, and the total free HAs was increased 20.44, 41.56, and 33.28 times by 1.0% pepper, 150% apple, and 150% onion. The sensitivity of HAs to different additives was variable, with the most significant changes observed in harman and norharman.

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

In this study, the release mechanism between free and sarcoplasmic protein-bound heterocyclic amines (HAs) in an in-vitro digestion model were investigated by comparing changes in the amount of HAs between groups with different enzyme dosages and at different digestion stages. The effects of the addition of onions, peppers, and apples on the release mechanism were also studied. We found that bound HAs cannot be completely converted to free HAs under normal enzyme dosages and that a significant increase in HAs occurred in the intestines. The release rate of bound HAs was 5.99%-43.84%, and the total release rate of HAs was 36.67%. Furthermore, the release rate of ß-carbolines was the highest (34.41%-43.84%). The addition of onions, peppers, and apples significantly increased the number of free HAs, with growth rates reaching 56.06%, 43.43%, and 54.44%, respectively. These additives mainly promoted the generation of free harman and norharman.

Simultaneous determination of the PhIP-proline adduct and related precursors by UPLC-MS/MS for confirmation of direct elimination of PhIP by proline.

The effect and elimination pathway of proline on reducing PhIP and the effect of processing temperature, duration, and proline addition on the PhIP-proline adduct and its precursors were investigated. The results have demonstrated that PhIP and proline could condense to produce the adduct by direct heating, which could also be detected in the PhIP-producing model system and in beef patties with proline. The analytical method was optimized and has a good limit of detection (0.006-73 ng/mL), limit of quantification (0.021-245 ng/mL), recovery rate (about 80%-120%), and precision (below 15%). A high dose of proline (5.0%, w/w) promoted the formation of the adduct and reduction of PhIP; long heating duration and high temperature were not conducive to the formation of the adduct in beef patties. With increased addition of proline, creatine and creatinine decreased in a dose-dependent manner; phenylalanine and glucose did not show the same trend.

Generation of Sarcoplasmic and Myofibrillar Protein-Bound Heterocyclic Amines in Chemical Model Systems under Different Heating Temperatures and Durations.

The protein-bound heterocyclic amines (HAs) and their generation pattern are still unclear. Generation of sarcoplasmic (SP)- and myofibrillar protein (MP)-bound HAs under different heating conditions was investigated in chemical model systems using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that eight types (387.01 ± 37.50 ng/100 mg MP) and six types (452.06 ± 33.32 ng/100 mg SP) of protein-bound HAs were generated at 180 °C/40 min, respectively. MP system can generate either more types or amounts of bound HAs at 90-150 °C. The main categories of protein-bound HAs in two systems were almost the same: ß-carbolines, α-carbolines, pyridines, and quinolines, among which nonpolar HAs dominated by ß-carbolines (at least 69.2%) are most easily formed. Principal component analysis revealed no significant difference in bound HAs at 90-120 °C but showed a significant increase at 150-180 °C. The higher the temperature, the more significant the differences between samples with different durations at the same temperature.

Non-precursors amino acids can inhibit ß-carbolines through free radical scavenging pathways and competitive inhibition in roast beef patties and model food systems.

The aim of this study was to investigate the inhibitory effect of non-precursors amino acids (histidine, leucine, proline and methionine) which have advantages of safety, inexpensiveness and high standardization on the formation of ß-carbolines in roast beef patties and glucose/creatine/creatinine/tryptophan model system, and the possible pathway of inhibition by monitoring the scavenging of free radicals by electron paramagnetic resonance (EPR) spectroscopy and the consumption of tryptophan by HPLC in a glucose/tryptophan model system. Almost all amino acids can inhibit ß-carbolines in roast beef patties (up to 80.62%) and model system (up to 67.01%). Histidine showed an excellent alkyl radical scavenging ability (up to 82.59%) and a highly competitive inhibition ability (up to 65.60%) against ß-carbolines generation. The corresponding abilities of leucine and methionine were less remarkable. Proline could only suppress ß-carbolines through competitive inhibition. The results could shed light on the reduction of ß-carbolines during meat processing.