Changes in nitrosohemachrome lead to the discoloration of spiced beef during storage

Effect of curdlan on the physicochemical properties and microscopic morphology of spiced beef during cooking and freezing

This study aimed to establish the functional influence of curdlan (0 %, 1.0 %, 2.0 %, and 3.0 %) on the quality of spiced beef through monitoring changes in cooking yield, textural properties, pH, oxidative stability, and micromorphology during marination, cooking and freezing. The results showed significant enhancements (P < 0.05) of viscosity and absorption yield of the marinade solution as well as the freezing rate of spiced beef upon, increasing the curdlan concentration. At a 2.0 % curdlan addition level, spiced beef showed the maximum tenderness (shear force), increased springiness and elasticity. Meanwhile, the colorimetric values were improved and lipid oxidation (peroxide; malonaldehyde) was consistently reduced during storage up to 14 days, whereas 3.0 % curdlan on day 14 exacerbated oxidation. Scanning electron microscopy and confocal laser scanning microscopy imaging of beef samples treated with 1.0 % and 2.0 % curdlan showed a relatively even distribution of curdlan within muscle fiber bundles, contrasting to 3.0 % curdlan treatment where curdlan accumulated mostly in the gaps between muscle bundles and fibers. Additionally, low-field NMR analysis demonstrated that the inclusion of 2.0 % curdlan significantly increased the immobile water content (P23). In corroboration, sensory analysis indicated that spiced beef treated with 2.0 % curdlan had the highest appearance, juiciness, taste, and flavor scores, suggesting that muscle structural improvement by the curdlan inclusion, optimal at the 2.0 % level, played a principal role in the quality enhancements of marinaded spiced beef.

Changes in physicochemical properties of snakehead fish slices incorporated with nano fish bones during freeze-thaw cycles: Effects of marinating methods

This study investigates the influence of nano fish bone (NFB) incorporated with different marination methods (traditional static marination (Ck), vacuum-assisted marination (VM), and ultrasound-assisted marination (US)) on the quality of snakehead fish slices subjected to 9 freeze thaw (FT) cycles. The NFB particles exhibited near-spherical surface and an average diameter of 197.5 nm. As compared with the marinade treated by Ck and VM, US facilitated the formation of smaller size and more uniform Pickering emulsion stabilized by NFB. Consequently, this method delayed changes in surface hydrophobicity (up to 15 %), sulfhydryl content (up to 20 %), and maintained secondary structure, water distribution while reducing cellular damage during FT cycles. These changes contributed to the slice quality by improving texture and reducing thawing (up to 25 %) and cooking loss (up to 30 %). Our findings suggest that NFB combined with ultrasound can enhance quality of aquatic products, intended for long-distance distribution and storage.

Effects of ultrasound-assisted tumbling on the quality and protein oxidative modification of spiced beef

The aim of this study was to investigate the effects of ultrasound-assisted tumbling (UT) with different ultrasound powers (frequency 20 kHz, powers of 0, 300 W, 450 W and 600 W) on the quality of spiced beef as explained from the perspective of the changes of muscle fibers and myofibrillar proteins (MPs). The results showed that pH value, tenderness and yield rate of UT groups were all apparently improved compared with the single tumbling group (P < 0.05). Ultrasound-assisted tumbling treatment could loosen muscle fiber structure supported by scanning electron microscopy (SEM) result, and the increased myofibrillar fragmentation index (MFI) value (P < 0.05). Additionally, an upward trend was observed in protein oxidation degree with the rise of ultrasound power level (P < 0.05), while the difference between groups in MPs solubility was not significant (P > 0.05). Above all, ultrasound-assisted tumbling treatment could effectively improve the quality of spiced beef by exacerbating the modifications in muscle fiber structure and MPs.

Effect of ultrasonic pretreatment with synergistic microbial fermentation on tenderness and flavor of air-dried duck under low nitrite process

The tenderness and flavor of meat products are critical factors influencing consumers' purchasing decisions. This study investigated the effects of ultrasonic pretreatment with synergistic microbial strain fermentation on tenderness and flavor of air-dried duck under low nitrite process. The results demonstrated that ultrasonic pretreatment combined with microbial strain fermentation improved water retention and tenderness of duck meat by disrupting the muscle microstructure, increasing muscle fiber spacing, and facilitating water migration and distribution. This primarily concerns the cavitation and mechanical effects of ultrasound and the role of lactic acid bacteria and yeasts in muscle protein hydrolysis. A total of 34 and 55 volatile flavor compounds were detected by HS-SPME-GC-MS and GC-IMS, respectively. The results indicated that acetaldehyde (stimulating, fruity, green apple), ethyl acetate (sweet, fruity, pineapple), and 3-hydroxy-2-butanone (sweet, creamy) were responsible for the improved flavor during this process, which was primarily related to the increased activity of neutral lipase (0.38 U/g protein), acidic lipase (0.48 U/g protein), and phospholipase (0.09 U/g protein). This study provides valuable insights into the synergistic effects of ultrasonic pretreatment and microbial co-fermentation, offering a theoretical basis for optimizing air-dried duck production and enhancing flavor quality.

Application of ultrasound treatment in pork marination: Effects on moisture migration and microstructure

To better understanding the effects of ultrasonic marination on the porcine tissue, the moisture migration and microstructure were investigated in this study. Additionally, the acoustic field distribution was analysis using COMSOL Multiphysics. The low-filed NMR results demonstrated that ultrasonic curing induced a leftward shift in T21 and a rightward shift in T22, accompanied by a significant reduction in A22, thereby enhancing the water-holding capacity of pork. The SEM and TEM observation showed that the presence of larger interstitial gaps between muscle fibers facilitated the diffusion of NaCl. The simulation analysis revealed that the acoustic field at 26.8 kHz showed minimal standing wave effects and more pronounced cavitation, which was the main reason for the best curing effect at this frequency. The scale-up test showed the NaCl content in pork reached 1% after ultrasound curing, indicating the potential application of ultrasonic marination technology in domestic refrigerators.

Emerging challenges and efficacy of polyphenols-proteins interaction in maintaining the meat safety during thermal processing

Polyphenols are well documented against the inhibition of foodborne toxicants in meat, such as heterocyclic amines, Maillard's reaction products, and protein oxidation, by means of their radical scavenging ability, metal chelation, antioxidant properties, and ability to form protein-polyphenol complexes (PPCs). However, their thermal stability, low polarity, degree of dispersion and polymerization, reactivity, solubility, gel forming properties, low bioaccessibility index during digestion, and negative impact on sensory properties are all questionable at oil-in-water interface. This paper aims to review the possibility and efficacy of polyphenols against the inhibition of mutagenic and carcinogenic oxidative products in thermally processed meat. The major findings revealed that structure of polyphenols, for example, molecular size, no of substituted carbons, hydroxyl groups and their position, sufficient size to occupy reacting sites, and ability to form quinones, are the main technical points that affect their reactivity in order to form PPCs. Following a discussion of the future of polyphenols in meat-based products, this paper offers intervention strategies, such as the combined use of food additives and hydrocolloids, processing techniques, precursors, and structure-binding relationships, which can react synergistically with polyphenols to improve their effectiveness during intensive thermal processing. This comprehensive review serves as a valuable source for food scientists, providing insights and recommendations for the appropriate use of polyphenols in meat-based products.

Formation mechanism of salted egg yolk mudding during storage: Protein oxidation, gel structure, and conformation

The aim of this study was to investigate the formation mechanism of salted egg yolk (SEY) mudding during storage. Results showed that the soluble protein, hardness, and intrinsic fluorescence intensity of SEY decreased significantly during storage, while total volatile basic nitrogen, sulfhydryl group, dityrosine, adhesiveness, and surface hydrophobicity increased significantly, and the intrinsic fluorescence peak position red-shifted at first and then blue-shifted. In addition, from the results of infrared and microstructure analyses, there was an obvious oxidation reaction between protein and lipid in the late storage stage; the structure of SEY was destroyed, many random coils were formed, and the degree of protein-lipid binding and the crystallinity of SEY protein decreased during storage. Finally, the heatmap analysis revealed that the protein and lipid oxidation and conformational changes might be the main reasons for SEY mudding. This study can provide theoretical guidance for the control of SEY mudding.

Transcriptome analysis reveals the potential mechanism of carotenoids change in hepatopancreas under low-temperature storage from swimming crab (Portunus trituberculatus)

The hepatopancreas of swimming crab (Portunus trituberculatus) rich in carotenoids would undergo serious color deterioration during cold storage, and then made portunid lose its commodity value. In this study, we firstly elucidated the change mechanism of its carotenoids during storage at the molecular level using transcriptome technology. We concluded that low-temperature would inhibit aerobic respiration of portunid, leading to a lower pH and inducing the degradation of carotenoids. After that, longer cold storage time would increase the oxidative stress in portunid, resulting in a further decrease in carotenoids content. Finally, the strong autolysis of portunid could release carotenoids stored in other parts such as ovary to the external environment, resulting in the increase of carotenoids detection content. This research could provide a basis for further developing the fresh-keeping technology of portunid during low-temperature storage.