Freezing technology extends the shelf life of products, reduces losses during long-distance transport, and makes it possible to industrialize food production. With the rapid growth of the prepared meat dish market in China, meat products need long-term cryogenic transportation and preservation. However, freezing technology faces some problems such as susceptibility to damage, quality decline, poor texture properties, water loss and taste deterioration during the freezing of meat products. Many kinds of food antifreeze agents are available now, which have a wide range of sources and low cost, and can solve the problem of freezing degeneration in various kinds of food. Therefore, food antifreeze agents play an extremely important role in improving the quality of frozen meat products. The development and application of food antifreeze agents are directly related to the development of the frozen meat industry. At present, the commonly used food antifreeze agents mainly include antifreeze protein, phosphate, and modified starch. Through different mechanisms of action, they can protect meat components, reduce ice crystal damage, increase water retention, and thus improve the quality of frozen food. In this paper, the types, mechanism of action and application of antifreeze agents in food are reviewed, aiming to provide more theoretical references for the wide application of antifreeze agents in meat products.

In the storage and processing of meat products, lipid hydrolysis is an important factor affecting the quality and flavor of meat products. Lipid hydrolysis occurs mainly due to the action of lipase, and different endogenous lipase acts on different sites of the lipid molecule to form a variety of products such as aldehydes, alcohols, esters and hydrocarbons, which greatly affects the flavor of meat products. Proper lipid hydrolysis is conducive to improving the flavor of meat products, but excessive lipid hydrolysis will lead to a decrease in the quality of meat products, protein oxidation and rancid odor. Furthermore, there is a correlation between lipid hydrolysis and lipid oxidation, and free fatty acids formed by lipid hydrolysis can be oxidized, resulting in a decrease in the quality and flavor substances of meat products. Controlling the degree of lipid hydrolysis is conducive to improving the quality of meat products and determining conditions that are more conducive to the preservation and processing of meat products. Lipid hydrolysis has a greater impact on unsaturated fatty acids, and the action of lipase on lipid has attracted the attention of many scholars. This paper reviews the mechanism of lipid hydrolysis in meat and meat products, and the resulting chemical changes as well as the influence of lipid hydrolysis on the quality and flavor of meant and meat products.

The emulsifying and gelling properties of myofibrillar proteins are extremely important for the texture, flavor, and sensory properties of foods. Non-meat proteins are gradually becoming a better choice for exogenous supplementation in meat products due to their higher nutritional value as well as lower price. This review focuses on the effect of the addition of various non-meat proteins on the emulsification of myofibrillar proteins and the stability of myofibrillar protein gel systems and analyzes the effect of non-meat proteins on the quality of meat products. This review will hopefully provide theoretical guidance for the application of non-meat proteins in improving the quality of meat products and in foods.

This study aimed to clarify the effect of adding different amounts of spray-dried blood cells (SBC), soybean protein isolate (SPI), egg white protein (EWP), or porcine plasma protein (PPP) on the quality and myofibrillar protein (MP) structure of minced pork. A sample with no added non-meat protein was used as a control. The cooking loss, color, pH value, microstructure and texture of meat samples were measured. The results showed that compared with the control group, the sample added with EWP showed a loose and porous structure and reduced water-holding capacity (WHC). The addition of PPP significantly improved the WHC, texture, and microstructure and increased the pH value of meat gels. The results of texture analysis showed that the addition of non-meat protein could significantly improve the chewiness of meat. The addition of SBC increased the redness value. Analysis of the secondary structure of MP demonstrated that the addition of PPP or SBC caused a red shift of the amide Ⅰ maximum absorption peak, indicating an increase in the α-helix content, and correspondingly the random coil content decreased, ultimately causing the gel structure to become denser and cause the gel strength and WHC to increase. The ultraviolet (UV) absorption intensity of MP treated with each of the non-meat proteins was decreased. The maximum absorption peak in the UV spectrum was slightly red shifted, indicating the occurrence of protein aggregation. In conclusion, adding SBC can effectively improve the quality of meat.

Lipids are important constituents of organisms. The type, structure and amount of lipids in meat can be investigated by various techniques such as mass spectrometry (MS), providing the basis for understanding the role that different lipids play in meat products. With the support of modern technology, the influence of lipidomics in meat research has gradually increased. Lipidomics allows visual understanding of the influence of lipids on meat quality and flavor, which has been increasingly applied in meat quality research by determining marker lipids. This paper summarizes recent research on the effect of different classes of lipids on meat quality, and reviews the application of lipidomics in meat research.

In this study, three different probiotics (Lactobacillus plantarum LP1, Lactobacillus fermentum LF1, and Bacillus subtilis BS1) were used to ferment chicken liver. Among these, Lactobacillus plantarum LP1 was found to have the strongest growth and acid production capacity and thus was selected as the starter for further fermentation. Single-factor experiments were carried out with five variables, initial fermentation pH, glucose addition, inoculum size, fermentation time and solid-to-liquid ratio. On this basis, the fermentation process was optimized by response surface methodology using three variables at three levels each. The results showed that the influence of three variables on the absorbance at 280 nm (A_{280 nm}) of fermented chicken liver was in decreasing order as follows: initial pH of fermentation medium > solid-to-liquid ratio > inoculum size. The optimal fermentation conditions were determined as initial pH of fermentation medium, solid-to-liquid ratio for 5.57, 1:3.55 (m/V) and 1.5%, respectively. The A_{280 nm} of fermented chicken liver obtained under the optimized conditions was 1.537. The total contents of free amino acids and essential amino acids in chicken liver increased significantly after optimization (P < 0.05), indicating that fermentation can promote the decomposition of chicken liver protein and thereby improve the nutritional value of chicken liver.

Phospholipase A₂ (PLA₂) is an important endogenous enzyme involved in lipid hydrolysis. It can specifically hydrolyze the unsaturated fatty acids at the sn-2 position of phospholipids in the cell membrane, changing the cell membrane structure and thus affecting its function. PLA₂ plays an important role in lipid hydrolysis during meat storage and processing, which affects the quality of meat. At present, there are few reviews on PLA₂ and its role in raw meat and meat products in China. In this paper, the general properties of PLA₂ and its relationship with meat products are reviewed. The structural classification of PLA₂, the methods for the extraction and purification of PLA₂, and its role in the hydrolysis and oxidation of raw meat are summarized, and the factors influencing the effect of PLA₂ on meat quality are described.

The objective of this study was to investigate the optimal conditions for the microwave combined with steam pretreatment of yellow-feathered broiler carcasses using response surface methodology (RSM). Microwave heating time, steam holding time and number of microwave combined with steam treatment cycles were considered as the independent variables, while the shear force and cooking loss of chicken breast meat were considered as response variables. The optimal processing parameters were as follows: microwave heating time of 30 s, steam holding time of 60 s, and 7 cycles of treatments. Under these conditions, the shear force of chicken breast was 18.31 N, and the cooking loss was 13.10%, both of which were close to the predicted values.

In this work, the effect of inactivation of enzymes on the salting quality of yellow-feathered broiler meat was addressed. The changes in the salt diffusivity (saltiness taste), umami taste, water retention properties (cooking loss, centrifugal loss and hydration capacity), water distribution, texture (hardness, chewiness, elasticity and viscosity) and microstructure of chicken meat were examined after salting. Hot meat and pre-cooled meat were considered as controls. The results showed that the salt diffusivity in chicken with enzyme inactivation was intermediate between that of hot meat and pre-cooled meat, whereas the umami taste was stronger than that of the controls. The cooking loss and centrifugal loss of chicken meat with enzyme inactivation were significantly reduced after salting, and the hydration capacity increased. Further investigation showed that lower mobility of bound water and immobilized water in chicken with enzyme inactivation contributed to higher water retention capacity. The hardness and chewiness of chicken meat with enzyme inactivation were significantly higher compared with the controls. The diameter of muscle fibers initially increased and decreased later with increasing salt concentration.

Heating is a common way of processing meat and meat products. Proper heating can improve the color and flavor, kill harmful microorganisms and parasites, extend the storage period, and improve nutrient digestion and absorption, but excessive heating will lead to the oxidation of unsaturated fatty acids in meat and promote the formation of harmful lipid oxidation products, thereby reducing the nutritional value of meat and affecting its food safety. This paper summarizes the recent advances in understanding the effect of lipid oxidation on meat flavor, introduces the mechanism of lipid oxidation, and summarizes the influence of heating temperature, time, method and additives on lipid oxidation in meat and meat products and the corresponding countermeasures. We anticipate that this review will provide a theoretical reference for lipid oxidation control in meat processing.