In this study, the sensory quality and shear force of bovine tripe were evaluated after instant boiling with salt-reduced hot pot seasoning with different proportions of substitution of KCl for NaCl, and changes in the contents of salt, sodium and potassium were examined. The results demonstrated that at all boiling times, the sensory score of bovine tripe cooked with hot pot seasoning at a NaCl/KCl ratio of 7:3 (m/m) was the highest. For each NaCl/KCl ratio level, the shear force increased with increasing cooking time, especially between 80 and 100 s. Similarly, the contents of salt, sodium and potassium significantly increased with increasing cooking time. For each cooking duration, the sodium content decreased with increasing substitution level of KCl, and the percent decrease was similar to the substitution percentage. Cooking bovine tripe with salt-reduced hot pot seasoning could reduce sodium intake by about 30% without affecting the flavor or eating quality of bovine tripe. It was recommended that the substitution percentage of KCl and the boiling duration of bovine tripe be 30% and 40 s, respectively.

Excessive fat is a common problem in sausage processing. Vegetable oils rich in n-3 fatty acid are a promising fat substitute due to their ability to reduce the risk of cardiovascular disease. Partially replacing animal fat with vegetable oils can improve the proportions of saturated fatty acids, unsaturated fatty acids and cholesterol in sausage and its nutritional quality, meeting people’s pursuit of health and nutrition. This review summarizes the effects of three types of oil-based fat substitutes (natural oil, pre-emulsified oil, and oleogel) on the processing, nutrition, sensory quality and safety of sausage. Recent progress in their application in reduced-fat sausage is summarized and future research directions are discussed, aiming to provide ideas for the development of new reduced-fat sausage products.

As a natural food additive, spices can significantly improve the sensory and physiochemical properties of foods, including improving the flavor and inhibiting microbial growth. Therefore, spices have been widely used in the food field, especially in meat products. Some pungent spices such as chili and prickly ash, which can endow meat products with unique spicy flavor and eliminate the unpleasant odor, have been indispensable base materials in the processing of meat products. The pungent spices play an important role in the diet culture in the provincial regions of Sichuan and Chongqing. Therefore, this review focuses on the flavor compounds of pungent spices and the influence of pungent spices on the flavor of meat products. Moreover, the advantages and disadvantages of several commonly used methods for the detection of the spices are compared. It is hoped that this review will provide a basis for the application of pungent spices in meat products.

In recent years, ultrasound has been widely used in the food industry as a promising non-thermal, green technology, but the exact effect of ultrasound on the physicochemical properties of myofibrillar proteins from Procambarus clarkii is not clear yet. This study investigated the effect of high-intensity ultrasound treatment at 300 W power and 20 kHz frequency for 0, 4, 8, 12 and 16 min during homogenization on the structure and physicochemical properties of myofibrillar proteins from Procambarus clarkii. The results showed that ultrasound treatment decreased the turbidity and mean particle size of myofibrillar proteins significantly (P < 0.05), but initially increased and then decreased the solubility and absolute value of ζ-potential, demonstrating altered degree of protein aggregation. The surface hydrophobicity and endogenous fluorescence intensity initially increased and then decreased with increasing treatment time; the total sulfhydryl group content significantly decreased (P < 0.05) while the carbonyl group content significantly increased (P < 0.05), demonstrating changes in the tertiary structure and a certain degree of protein denaturation. In addition, the relative contents of α-helix and random coil increased first and then decreased, whereas the opposite trend was observed for the proportion of β-sheet, indicating changes in the secondary structure. These results showed that high-intensity ultrasound treatment could affect the physicochemical properties, structure and aggregation degree of myofibrillar proteins from crayfish meat, which could provide a reference for the application of ultrasound as an auxiliary approach in the processing and storage of crayfish.

In this study, the effects of different freezing methods and temperatures (freezer at –20 and –50 ℃, and liquid nitrogen at –50 and –80 ℃) on the water-holding capacity and structural properties of myofibrillar proteins from the hind leg muscle of Rana nigromaculata were investigated. The results showed that the time required for hind legs frozen in freezer at –20 and –50 ℃ and with liquid nitrogen at –50 and –80 ℃ to pass through the zone of maximum ice crystal formation temperature (–1 to –5 ℃) were 91.5, 57.0, 1.5 and 0.5 min, respectively. Compared with the freezer freezing groups, the liquid nitrogen freezing groups exhibited reduced thawing loss, increased content of immobilized water, and decreased content of free water. Compared with fresh samples, the water-holding capacity, solubility, total sulfhydryl content and endogenous fluorescence intensity of myofibrillar proteins decreased significantly after freezing, and the particle size, surface hydrophobicity and relative content of random coil showed an increasing trend. In the –50 ℃ liquid nitrogen freezing group, the water-holding capacity, protein solubility, total sulfhydryl content and endogenous fluorescence intensity decreased by 8.10%, 9.57%, 10.50% and 67.36%, respectively, and the volume average particle size, surface hydrophobicity and random coil content increased by 100.05%, 82.24% and 13.65%, respectively; these changes were significantly lower than those in the other freezing groups (P < 0.05). The degree of myofibrillar protein denaturation in the –80 ℃ liquid nitrogen freezing group was significantly lower than that in the –20 ℃ freezer freezing group, but higher than that in the –50 ℃liquid nitrogen freezing group (P < 0.05). According to the results of scanning electron microscopy (SEM), muscle fibers were more tightly and regularly arranged in the –50 ℃ freezer freezing and –50 ℃ liquid nitrogen freezing groups, while those in the –80 ℃ liquid nitrogen freezing group were arranged regularly but slightly cracked, and those frozen in the –20 ℃ freezer freezing group were obviously broken. These findings indicate that liquid nitrogen freezing can slow down the migration of water in the hind leg muscle of R. nigromaculata and effectively inhibit the cold denaturation of myofibrillar proteins, the effect being more pronounced at –50 ℃ than at –80 ℃.

In this study, the effects of the addition of different amounts of salt (0%, 1%, 2% and 3%) at five stages of processing: raw shrimp, blanching, marination, soaking for 2 h and soaking at 4 ℃ for 24 h, on the quality and volatile flavor compounds of marinated crayfish were investigated. The results showed that L^* values increased and then decreased as the processing stages proceeded, while a^* and b^* values both continued to increase. But salt addition had little effect on the color difference. Additionally, moisture content decreased and then increased, and was affected little by salt addition. For 1%, 2%and 3% salt addition, hardness, elasticity, chewiness and adhesion showed an initial increasing and subsequent decreasing trend. Without salt addition, hardness and chewiness continued to increase. For each group, elasticity and cohesiveness increased and then did not show any significant change. The electronic nose results could be roughly divided into four parts, raw shrimp and blanching, marination, soaking for 2 h, and soaking at 4 ℃ for 24 h. There were also some differences between the less and more salt addition groups. The electronic tongue results showed that as salt addition increased or the processing stages proceeded, saltiness, astringency, and umami taste increased, and other taste attributes changed little. Gas chromatography-ion mobility spectrometry (GC-IMS) analysis showed that salt addition and marination had a positive effect on the volatile flavor of crayfish. However, excessive salt addition and too long processing time were detrimental to volatile flavors. In conclusion, the addition of salt and processing stages can affect the quality and flavor of marinated crayfish.