Beef is rich in nutrients and is one of the most important ingredients in the world. But in the process of cooking and heating, the nutrients of beef will change to varying degrees. How temperature affects the oxidation of lipids and proteins in beef, and the modification of amino acid residues is unclear. This study intended to heat beef at different roasting temperatures (150 °C, 190 °C, 230 °C, 270 °C, 310 °C), measure parameter including colour, peroxide value (PV), thiobarbituric acid-reactive substances (TBARS), thiol and carbonyl content, protein solubility, tryptophan and Schiff base content, protein molecular weight distribution and modification of amino acid residues to discussed the effects of different temperatures on the lipid and protein oxidation of beef patties, as well as the modification of amino acid residues. The results showed that the values of L* and b* increased with the temperature increased, and the values of a* decreased. With the increase of temperature, the lipid oxidation indexes PV and TBARS, Schiff base and carbonyl content also increased, and the thiol content and protein solubility decreased significantly (p < 0.001). SDS-PAGE showed that the band of myosin heavy chain (MHC, 220 kDa) was significantly degraded, while the band of actin (42 kDa) was still clearly visible. The analysis of UPLC-MS/MS results found that the aromatic amino acid residues in all samples were oxidized to a certain extent, especially tryptophan. Other oxidative modifications, including α-amiooadipic acid (AAA), hydroxyethyl lysine (CEL) and malondialdehyde (MDA), were only present in roasted samples and not in raw meat. The results suggested that lipid oxidation and protein oxidation were closely related to colour parameters. The oxidation of proteins and lipids was aggravated at higher temperature. Amino acid side chains were also modified at high temperature, and this change was particularly evident in aromatic amino acids. These results provided new insights for the oxidation of proteins and lipids of beef and the modification level of amino acid residues under high temperature conditions, which will help us to improve the cooking quality of meat foods.

This study examined the effects of varying microwave treatment durations (0–120 s) on the structural and functional properties of glycosylated soybean 7S protein. The results indicated that microwaving for 60 s significantly altered the structure of 7S, resulting in a more ordered protein configuration. The treated protein exhibited the largest particle size (152.3 nm), lowest polydispersity index (0.248), highest α-helix content (47.86%), and lowest β-sheet, β-turn, and random coil contents (12.33%, 16.07%, and 22.41%, respectively). It also showed the lowest endogenous fluorescence and surface hydrophobicity, and the highest thermal denaturation temperature (76.8 °C). Additionally, microwaving for ≤90 s led to increased peptide modifications, with carbamylation and deamidation being the most prevalent. A microwave treatment time of 60 s also notably enhanced the functional properties of glycosylated soybean 7S protein, optimizing water-holding capacity (6.060 g/g), emulsification activity, and stability (45.191 m²/g and 33.63 min). The foaming capacity was second only to the 120 s treatment (32% at 60 s versus 34% at 120 s), though the oil-holding capacity (22.73 g/g) and foaming stability (33.42%) were significantly lower than those of the controls. Microwave treatment durations exceeding or below 60 s led to the structural disintegration of the protein, diminishing most of its functional properties. This study explores the mechanism of how microwave processing time affects the structure and functional properties of glycosylated soybean 7S protein and identifies 60 s as the optimal microwave processing time. It meets the demands for healthy and delicious food in home cooking, providing scientific evidence for using microwave processing technology to enhance the nutritional value and quality of food.

Beef is one of the important red meat, which contains essential nutrients for human growth and development. baking is a popular beef cooking method. Temperature and time play a key role in the final quality of beef. How temperature and time affect the changes of nutrients and the formation of harmful products in beef is not clear. The purpose of this study was to measure the content of water, fat, protein, ash, nitrite, total volatile base nitrogen, advanced glycation end products (AGEs) and its precursors and polycyclic aromatic hydrocarbons (PAHs) at different temperatures (150℃, 190℃, 230℃, 270℃ and 310℃) for 20 min and 190℃ for different times (10 min, 20 min and 30 min), so as to discuss the effect of different temperatures on beef nutrients and harmful products. The results showed that the moisture content of beef decreased with the increase of baking temperature and time, resulting in the increase of the relative content of fat, protein and ash. At the same time, the content of total volatile base nitrogen also increased continuously. Compared with the control group, the content of glyoxal (GO) in beef decreased, while the content of methylglyoxal (MGO), pentosin and fluorescent AGEs increased, indicating the continuous accumulation of AGEs in beef. A total of 13 PAHs were identified by gas chromatography-mass spectrometry (GC-MS). The content of 13 PAHs in beef increased with the increase of baking temperature and time. Among them, BkP and BaP, which are the most carcinogenic to human body, were 0.36 μg/kg in raw meat and 0.35 μg/kg respectively, which was doubled by high temperature and long-time baking. After beef was baked at 270℃ and 310℃ for 20 min, the content of BkP increased to 9.49 μg/kg and 5.66 μg/kg, the content of BaP increased to 5.45 μg/kg and 4.42 μg/kg, respectively. After baking at 190 ℃ for 30 min and 40 min, the content of BkP increased to 4.81 μg/kg and 24.20 μg/kg, content of BaP increased to 3.85 μg/kg and 17.79 μg/kg, respectively.

Aims The aim of this research is to study the removal characteristics and evaluate the detoxify action of deoxynivalenol by Bacillus natto 16 in wheat flour as food or feed. Methods and Results The content of deoxynivalenol was determined using ELISA by testing the deoxynivalenol removal rate, and the influence of culture supernatant, intracellular substances, crude enzyme and cell wall on the deoxynivalenol in wheat flour was studied. The effect of bacterial components on the removal of deoxynivalenol was studied in the artificial gastrointestinal environment to simulate the digestion of food. Secondary metabolites were analysed by high‐performance liquid chromatography in tandem with mass spectrometry (HPLC‐MS).The cell wall can reduce the content of deoxynivalenol in the sample by adsorption, the influence of culture supernatant, intracellular substances and crude enzyme can convert deoxynivalenol into substances with a lower molecular weight. Bacterial components have no effect on deoxynivalenol in wheat flour in simulated gastric fluid and have a certain removal effect on deoxynivalenol, which is closely related to intestinal digestion time and pH, in simulated intestinal fluid. Conclusions Experimental results indicate that the removal of deoxynivalenol by Bacillus natto 16 includes adsorption and biodegradation, simulated gastric fluid would invalidate the deoxynivalenol removal activity of Bacillus natto 16’s components. Significance and Impact of Study Our study showed that as an edible probiotic bacterium, Bacillus natto 16 can effectively remove deoxynivalenol from wheat flour as food or feed, and can be used a new deoxynivalenol ‐detoxifying microbe. The results of this research could provide the theory foundation for further development and application of Bacillus natto 16.

The β-conglycinin (7S) was pre-treated with high-intensity ultrasonic (HIU) and subsequently formed into composite edible films with the transglutaminase (TGase) method. Effects of HIU pretreatment time (0, 5, 10, 15, and 20 min) on the conformation of 7S and structural and application properties of 7S-TGase films were evaluated. The analysis of 7S conformation results revealed that HIU pretreatment for 0-10 min significantly dissociated the 7S, exposed internal hydrophobic groups of protein, increased its intermolecular hydrogen bonds, and altered the protein secondary and tertiary structure. The structural properties of films were evaluated by SEM, XRD, and ATR-FTIR. SEM showed that HIU reduced film wrinkles and cracks and improved unevenness. XRD and ATR-FTIR indicated that the film obtained an enlarged crystallinity, and the amide I and amide II regions of films were peak-shifted which is usually associated with the formation of covalent bonds. Notably, analysis of intermolecular force showed that HIU facilitated the formation of hydrogen bonds, hydrophobic interactions, and ε-(γ-glutamyl) lysine bonds in 7S-TGase films. The above structural changes in 7S and films were beneficial for the application properties of films. Results indicated that 10 min HIU pretreatment effectively improved the mechanical properties and water resistance, reduced water vapor permeability and oxygen permeability, and decreased the opacity of 7S-TGase films. However, the color of the film was not affected by the HIU, with an overall bright and yellowish color.