Effect of stewing time on fatty acid composition, textural properties and microstructure of porcine subcutaneous fat from various anatomical locations

Crucial textural properties of braised pork to evaluate the oral mastication behavior and its water distribution to influence tenderness

The complex composition of braised pork, including lean meat, pigskin, and fat, makes it difficult for sensory evaluation of its texture properties. This study investigated the correlation between sensory texture attributes and physicochemical properties to achieve an objective and comprehensive evaluation of the texture of braised pork. Sensory analysis demonstrated that the overall texture acceptability of braised pork was significantly and negatively influenced by sensory texture attributes (including sensory hardness, chewiness, and toughness), while it was positively impacted by sensory adhesiveness, softness, and juiciness. Shear force and texture profile analysis (TPA) variables, reflecting mastication behavior, were used to characterize the textural properties of braised pork. They were closely related to water distribution, with a higher proportion of immobilized water (P21), indicating a higher water holding capacity and a more tender texture. Correlation analysis between sensory texture attributes and physicochemical properties through partial least squares regression further revealed significant associations between shear force, TPA variables, and sensory texture attributes. Moreover, the proportion of immobilized water (P21) significantly and negatively affected sensory hardness and chewiness, whereas the proportion of free water (P22) significantly influenced sensory toughness. Sensory texture attributes could be well predicted by the physicochemical properties by projecting test samples onto calibration models established by known samples. Therefore, a combination of sensory and instrumental measures can reliably reflect the texture properties of braised pork. PRACTICAL APPLICATION: The combination of sensory and instrumental methods is an effective strategy to accurately and objectively evaluate the texture properties of braised pork, which overcomes the limitations caused by the complexity of the composition and texture traits of braised pork. The accurate evaluation and standardization of texture properties is an important premise for the repeatable and stable cooking of traditional braised pork. Furthermore, this research method and findings can also be applied to guide the procedural optimization of smart appliances (e.g., induction cookers) for cooking braised pork.

Effect of different sous-vide cooking temperature-time combinations on the functional and sensory properties of goose meat

The effect of goose meat sous-vide (SV) cooking at 6 combinations of temperature (60°C, 80°C) and time (4, 6, 12h) on selected functional properties was investigated. The study conducted an assessment of cooking loss (CL), moisture content, pH, longitudinal (LS), and transverse (TS) shrinkage, shear force (SF), texture profile analysis (TPA), color parameters (L*, a*, b*, C, h°), ΔE and carried out sensory evaluation. A total of 168 breast muscles (BM with and without skin) from 17-wk-old "Polish oat geese" were utilized. The CL was affected by both cooking temperature and time. The CL for meat with skin was higher than for without ones, and it was lower for both kinds of meat cooked at 60°C than at 80°C for all cooking times. The LS was higher than the TS. The higher shrinkage was stated for meat cooked at 80°C. There was a reduction in moisture content and slightly increasing pH by increasing temperature and prolonging cooking time. For both kinds of meat, the highest moisture retention was stated at 60°C/4h, and the lowest in samples heated at 80°C/12h. The samples cooked at 60°C were characterized by a higher L* value than those at 80°C. The a* values were higher for samples cooked at 60°C than those at 80°C, whereas b* were higher for meat cooked at 80°C. The SF exhibited a trend of lower values at 60°C compared to samples cooked at 80°C and it increased with prolonged cooking time. The value of hardness, cohesiveness, springiness, gumminess, and chewiness for meat cooked at 60°C increased, and for samples cooked at 80°C decreased with increasing cooking time. It was no significant differences in sensory scores for overall palatability for both kinds of meat cooked at 60°C and 80°C. Goose meat cooked at different time and temperature combinations showed extremely desirable overall palatability. Taking into account all discussed parameters, the optimal combination seems to be 60°C/4h.

Unveiling microwave and Roasting-Steam heating mechanisms in regulating fat changes in pork using cell membrane simulation

Fat reduction due to heating or cooking is an important issue in a healthy diet. In the current study, pork subcutaneous back fat was treated via microwave heating (MH) within 10-90 s and roasting - steam heating (RSH) within 2-30 min and their dynamic changes of individual adipocytes were explored by using vesicles as a bio-membrane model. The result showed that MH and RSH significantly increased fat loss (P < 0.05), with the maximum losses being 74.1 % and 65.6 %, respectively. The mechanical strength of connective tissue decreased and then increased slightly. The microstructure demonstrated that MH and RSH treatments facilitated a large outflow of fat, showing that the particle size of the vesicle and individual adipocytes increased and then decreased. It is thus feasible to study the dynamic changes of individual adipocytes in regulating fat reduction using cell membrane simulation.

Mechanism underlying the tenderness evolution of stir-fried pork slices with heating rate revealed by infrared thermal imaging assistance

This study aimed to explore the mechanism of cooking intensity on the tenderness of stir-fried pork slices from the perspective of the changes in temperature distribution. Infrared thermal imaging was used to monitor the distribution of temperature. Results showed that the high-level heat (HH) treatment could improve tenderness. When the center temperature increased to 100 °C, the shear force of samples from the low-level heat (LH) group increased by around 3-fold, and HH reduced this upward trend. This result was mainly attributed to the shorter heating time undergone by the HH-treated samples compared to the LH treatment, which resulted in less structural shrinkage and faster passing through the protein denaturation interval of the samples. These changes alleviated temperature fluctuations caused by water loss. This explanation could be confirmed by the results of T2 relaxation time and Fourier transform-infrared spectroscopy (FT-IR). However, the LH treatment caused a slower rise in oil temperature due to more moisture migration, which required the samples to undergo longer thermal denaturation, leading to a deterioration in tenderness. Moreover, histological analysis revealed that the greater integrity of endomysium in the HH group inhibited water loss and oil absorption, which contributed to obtain low-fat meat products with higher tenderness. This study provides support for the industrialization of traditional pork cuisines using oil as the heating medium.

Exploring the formation of a transparent fat portion in bacon after heating based on physicochemical characteristics and microstructure

Bacons, which possess a transparent fat tissue after heating, have high commercial value in China owing to their good sensory quality. This study was performed to explore the formation of transparent fat tissue by comparing the physicochemical characteristics and microstructures of transparent and non-transparent fat tissues. The physicochemical characteristics and microstructure of fat tissue were found to be significantly affected by drying, which increased the saturated fatty acid content and oxidation level, and decreased the moisture content and water activity (p < 0.05). Shrivelled adipocytes were observed in fat tissue after drying. Transparent and non-transparent fat tissues differed significantly in terms of moisture, fat content, texture, and fatty acid composition (p < 0.05). Multivariate statistical analysis indicated that low moisture content might be the major factor in the formation of transparent tissue, while the destruction of adipocytes also contributed to such formation.

Volatile compounds comparison and mechanism exploration of non-smoked traditional Chinese bacon in Southwestern China and Eastern China

Non-smoked traditional Chinese bacon is popular in China. However, the aromas of the non-smoked bacon from Eastern China (EC bacon) and Southwestern China (SW bacon) differed significantly. This study investigated these differences and the key volatile compound formation mechanisms. A total of 175 volatile compounds were detected in the bacon samples, while 32 key aroma compounds were screened based on odor activity values (OAVs). Multivariate statistical analysis showed that ten odorants could be considered discriminative compounds, including hexanal, octanal, and 1-octen-3-ol, etc. The fatty aroma of EC bacon was mainly attributed to a higher aldehydes content, which is due to more oxidation of fatty acids. Meanwhile, the SW bacon smelled sweeter since there was more ester in the sample. The correlation analysis between the fatty acid profiles and key aroma compounds indicated that the discriminative aldehyde formation in the EC bacon was primarily attributed to oleic and linoleic acid oxidation, which were both potential biomarkers.

Effect of High Pressure/Heating Combination on the Structure and Texture of Chinese Traditional Pig Trotter Stewed with Soy Sauce

In order to clarify the effect of a high pressure/heating combination on the texture of Chinese traditional pig trotter with soy sauce, textural parameters (springiness, chewiness, hardness, and gumminess), the secondary structures, cross-links, decorin (DCN), glycosaminoglycans (GAGs) levels, and the histochemical morphology of collagen fibers under different treatments (0.1 MPa, 150 MPa, 300 MPa, 0.1 MPa + 50 °C, 150 MPa + 50 °C, and 300 MPa + 50 °C) were assessed. At room temperature, the 150 and 300 MPa treatments increased the hardness and chewiness of the pig trotter with weak denaturation of collagen proteins compared with the control group. Textural parameters were improved at 300 MPa + 50 °C, accompanied by an ultrastructural collapse of collagen fibers, the reduction in cross-links, DCN and GAGs levels, and unfolded triple-helix structure. We concluded that the positive effects on the textural parameters of pig trotters by a combination of treatments could be attributed to the collapse of collagen structure.