Yajun Zhou

BACKGROUND: The gelation properties of myofibrillar protein (MP) directly affect the texture, taste and water‐holding capacity (WHC) of meat products. To enhance the gelation properties of single‐species meat MP, the present study investigated the influence of different proportions of beef, pork and chicken MP on the physicochemical properties, structure and gelation properties of the MP.RESULTS: The results revealed that, when the proportion reached 5:2:3, the particle size decreases, leading to the maximum decomposition and unfolding of MPs, which exposes a greater number of hydrophobic amino acid residues. These changes promote interactions between protein molecules, especially the unfolding of α‐helices and the formation of β‐sheets during the heating process, which provides favorable conditions for the formation of protein gels and improves the gel strength and WHC of MP gels. Additionally, scanning electron microscopy revealed that the mixed MP gels are more compact and have more uniform gel networks and pores compared to single‐species MP gels.CONCLUSION: Based on these results, the synergistic effect is induced by the interactions between proteins from different. This research provides a method for the subsequent development of new meat products and improvement of meat product quality, and also lays a theoretical foundation for composite research of proteins from different sources. © 2024 Society of Chemical Industry.

BACKGROUND: Complex phosphates (CP) can improve the physicochemical properties and gelation properties of myofibrillar fibrous protein (MP) in mixed meat products, but an excessive intake of phosphates over a long period of time is harmful to health. The present study investigated the effects of partial or complete substitution of CP with sodium bicarbonate (SB) on the physicochemical properties and gel properties of beef‐pork‐chicken mixed myofibrillar protein (BPC‐MP), aiming to evaluate the feasibility of this method in reducing the amount of phosphate in mixed meat products.RESULTS: Under the optimal substitution conditions, the turbidity of BPC‐MP was reduced by 37.8%, the net negative potential was increased by 28.9% and the modulus of elasticity (G') was increased. The tertiary structure indexes of protein (including fluorescence intensity, surface hydrophobicity and active thiol content) were significantly changed, whereas the α‐helix and β‐turn angle contents in the secondary structure of protein were significantly increased. In addition, the water retention ability and strength of gel were also improved, which were increased by 20.7% and 42.6%, respectively. The results of scanning electron microscopy showed that the SB substitution group had a more compact and ordered microstructure.CONCLUSION: The results showed that partial substitution of CP with SB reduced the amount of phosphate added to BPC‐MP and had a positive effect on the physicochemical and gel properties of BPC‐MP. © 2024 Society of Chemical Industry.

BACKGROUND: Heterocyclic amines (HAs) and N‐nitrosamines (NAs) are formed easily during the thermal processing of food, and epidemiological studies have demonstrated that consuming HAs and NAs increases the risk of cancer. However, there are few studies on the application of back propagation artificial neural network (BP‐ANN) models to simultaneously predict the content of HAs and NAs in sausages. This study aimed to investigate the effects of cooking time and temperature, smoking time and temperature, and fat‐to‐lean ratio on the formation of HAs and NAs in smoked sausages, and to predict their total content based on the BP‐ANN model.RESULTS: With an increase in processing time, processing temperature and fat ratio, the content of HAs and NAs in smoked sausages increased significantly, while the content of HA precursors and nitrite residues decreased significantly. The optimal network topology of the BP‐ANN model was 5–11–2, the correlation coefficient values for training, validation, testing and all datasets were 0.99228, 0.99785, 0.99520 and 0.99369, respectively, and the mean squared error value of the best validation performance was 0.11326. The bias factor and the accuracy factor were within acceptable limits, and the predicted values approximated the true values, indicating that the model has good predictive performance.CONCLUSION: The contents of HAs and NAs in smoked sausages were significantly influenced by the cooking conditions, smoking conditions and fat ratio. The BP‐ANN model has high application value in predicting the contents of HAs and NAs in sausages, which provides a theoretical basis for the suppression of carcinogen formation. © 2024 Society of Chemical Industry.

Summary: Spiced pork shoulder is a traditional Chinese meat product that is loved by consumers. However, heterocyclic aromatic amines (HAAs) formed by spiced pork shoulder during processing endanger human health. The present study determined the HAA contents of seven kinds of spiced pork shoulder, and examined the effects of soy sauce, cooking wine and sugar on the formation of HAAs. The total HAAs of the seven samples were between 0.10 ng/g and 56.82 ng/g. There were Harman (0.03–39.77 ng/g) and Norharman (0.06–18.76 ng/g) correlations in all samples. Not all samples had higher HAAs levels in the skin than the whole shoulder. Creatine and creatinine were more actively involved in the formation of HAAs than glucose. Soy sauce contributed the most to the formation of HAAs, followed by cooking wine and sugar. Compared to spiced pork shoulder, the soup contained more HAAs. Exogenous contamination of HAAs in soy sauce, cooking wine and soup was an important source of HAAs in spiced pork shoulder.