Recent advances in the study of modified cellulose in meat products: Modification method of cellulose, meat quality improvement and safety concern

The inhibition potentiality of sodium carboxymethyl cellulose on PhIP, Harman, and Norharman formation of fried beef patties at low NaCl level

The objective of this study was to investigate the inhibitory effect of sodium carboxymethyl cellulose (CMCNa) on the formation of heterocyclic aromatic amines (HAAs) in fried beef patties under low salt conditions. The 0.5-1.5 % of CMC-Na was introduced to minced beef at 1 % NaCl level, and the formation of HAAs was found to be significantly inhibited after fried (P < 0.05). The inhibition observed in the treatment containing 1 % NaCl +1.5 % CMC-Na was found to be statistically significant (P < 0.05). Specifically, compared to the control treatment, the contents of Harman, Norharman and PhIP were effectively reduced by 58.9 %, 66.1 %, and 67 %, respectively, in this treatment. CMC-Na inhibited the generation of HAAs through a water retention mechanism under low-salt conditions and formed a tight three-dimensional gel network structure of the minced meat, thus preventing the migration of fixed water to free water. This helped to mitigate the temperature rise on the surface of the beef patty while reducing the rate of pyrolysis of precursors of HAAs. CMC-Na can be utilized as a food additive during the preparation of fried beef patties under low-salt conditions to significantly diminish HAA formation and enhance food safety.

Tailoring cellulose: from extraction and chemical modification to advanced industrial applications

Cellulose is a natural polymer with excellent physicochemical properties that can be extracted from various plant sources and has widespread applications across multiple industries. Due to its biodegradability, renewability, and mechanical strength, cellulose has gained significant attention in fields such as pharmaceuticals, food packaging, sensors, water treatment, and textiles. However, its inherent limitations, such as poor solubility, low electrical conductivity, and limited functionality, hinder its application in advanced technologies. To overcome these challenges, chemical modifications have been extensively explored to enhance its structural properties and broaden its utility in specialized applications. This review explores the modifications applied to cellulose with a focus on targeted advanced industries. Emphasis is placed on identifying the limitations of cellulose in each industry and highlighting the most recent techniques available for modifying its properties to meet specific requirements. Finally, this review discusses the challenges associated with cellulose processing and the high costs of extraction while providing insights into future research directions and potential advancements in cellulose-based technologies.

Inhibition effect and mechanism of hydrocolloids on the formation of heterocyclic aromatic amines (HAAs) in meat products: A review

Hydrocolloids are another potential exogenous additive and shows efficient effect in minimizing the formation of toxic by-products during high-temperature processing attribute to their unique structure and high solubility. Therefore, this review provided for the first time comprehensive summary and proposed new insights into the inhibitory effect and mechanism of hydrocolloids on HAAs formation in meat products. Effects of the combined use of hydrocolloids and polyphenols on the HAAs formation inhibitory effects were discussed and highlighted as well. Hydrocolloids, used alone or with polyphenols, can effectively inhibit HAAs formation. Among some common hydrocolloids, carrageenan and chitosan have significant inhibition effect on HAAs formation. Their water retention properties, free radical scavenging ability, and inhibition of Maillard reaction were elucidated as the in-depth mechanism for inhibiting the HAAs formation. This review can provide theoretical reference for hydrocolloids effectively controlling HAAs formation in thermal-processed food, and reducing their harm to human health.

Cellulose-based delivery systems for bioactive ingredients: A review

Considering the outstanding advantages including abundant resources, structure-performance designability, impressive mechanical strength, and 3D network structure-forming ability, cellulose is an ideal material for encapsulating bioactive ingredients. Due to its low solubility in water, large-scaled morphology and poor flexibility, cellulose is unsuitable for the construction of carriers. Consequently, the majority of cellulose is employed following physical or chemical modification. Cellulose and its derivatives are extensively employed in the food industry, including fat replacement, food packaging composites, food additives, 3D-printed food and delivery systems. Their benefits in food delivery systems are particularly pronounced. Therefore, the distinguishing features, preparation methods, recent developments and effectiveness of different cellulose-based delivery systems for bioactive ingredients are discussed. Cellulose-based delivery systems offer unique advantages in terms of environmental impact reduction, modification facilitation, stimuli-responsive release as well as tailored design, and their application has gained widespread recognition. However, they are facing challenges in the application process comprising modification methods for cellulose-based materials, new methods for commercial preparation on a wide scale, cellulose-based multifunctional conveyance systems and systematic evaluation using in vivo experiments. In conclusion, this review provides theoretical references for the development of novel delivery carriers as well as the efficient application and popularization of cellulose-based delivery systems.

Okra cellulose crystals stabilized Pickering emulsion: A practical tool for soybean oil inclusion to improve nutritive profile of sausages

Pickering emulsions stabilized by okara cellulose crystals and the cellulose crystals modified with tannic acid were prepared and used to substitute porcine fat for sausage preparation. Both used cellulosic materials could effectively preserve dispersibility and heat stability of the emulsions. There was improved sausage stability when the emulsions stabilized by the cellulosic materials were used to replace pork backfat in the sausage formulation. The sausages added with the cellulosic material-based emulsions, especially the ones stabilized by the okara cellulose grafted with tannic acid, possessed better oxidative stability during storage than the control added with porcine fat. Moreover, lowered lipolysis degree could be found for the sausages added with the cellulosic materials stabilized emulsions as compared to the control formulation. Therefore, incorporation of the emulsions stabilized by the cellulosic materials might be a feasible way to improve nutritive profile by lowering saturated fatty acid content and energy uptake of the sausages.

Wax Coatings for Paper Packaging Applications: Study of the Coating Effect on Surface, Mechanical, and Barrier Properties

The aim of this study was to comprehensively assess the effect of environmentally friendly wax coatings, including beeswax, soywax, TopScreen biowax, and a conventional water-based emulsion wax on paper for food packaging applications. A food-grade paper was bar-coated with a single layer of molten wax on both sides, varying in the coating weight, coating thickness, and wax type. Waxes were thoroughly characterized in terms of their functional groups, thermal properties, degree of crystallinity, and crystal morphology using polarized optical microscopy. Thereafter, wax-coated papers were studied in terms of their morphological, mechanical, and water vapor barrier properties. Moreover, the water and oil contact angles were measured to determine the resistance of wax-coated papers to moisture and grease penetration. Wax coatings represent 10-25% of the weight of the coated paper, with a coating thickness of 5-10 μm. Scanning electron microscopy images showed that waxes penetrated the cellulosic fibers of the paper, thereby effectively reducing its porous structure. Water and oil contact angles of the uncoated paper increased after the wax coating. Among the four waxes, beeswax-coated paper was characterized as having superior capability in improving the water vapor barrier of the uncoated paper (by ∼77%). While the percentage elongation at break (EB %) decreased for all four wax-coated papers, tensile strength (TS) and elastic modulus (E) increased, with beeswax showing the highest percent improvement in TS (by ∼26%) and E (by ∼46%). Our results suggest that paper surface modification through ecofriendly wax coatings can be utilized as an alternative for petroleum-based paper coating materials for food packaging applications.

Effects of Flammulina velutipes powder on the emulsion properties of chicken myofibrillar protein under low-salt conditions

This study aimed to investigate the influence of varying concentrations of Flammulina velutipes powder (FVP) (0, 4, 8, 12, 16, and 20 g L-1, based on FVP weight per liter of emulsion) on the stability, rheological properties, microstructure, and interfacial protein content of chicken myofibrillar protein (MP) emulsions under low-salt conditions. Visual assessment and the Turbiscan stability index revealed that the stability of MP emulsions improved with increasing FVP concentration. The greatest stability was achieved when the FVP concentration was 16 gL-1. The incorporation of FVP enhanced the elasticity and viscosity of the emulsions by forming a dense three-dimensional network structure. The droplet size of the emulsions initially decreased and then increased with increasing FVP concentration. The addition of FVP increased the amount of protein absorbed by the emulsion layer. Flammulina velutipes powder is promising as a stabilizer that could improve the emulsifying and functional properties of low-salt myofibrillar protein emulsions. © 2024 Society of Chemical Industry.

Preparation and characterization of carvacrol/soybean protein isolate composite film with efficient antimicrobial and antioxidant activities and its application in grape preservation

There is an urgent need for a simple and effective method to enhance the freshness of fruits during transportation. In this study, we developed a composite antibacterial film (CAR film) using carvacrol and soy protein isolate (SPI). The mechanical properties, hydrophobicity, antibacterial activity, and antioxidant capacity of the film were characterized. The results demonstrated that, compared to the soy protein isolate film, the film with 2.5 % carvacrol content exhibited superior mechanical properties (tear strength decreased by approximately 37 %, elongation at break increased by about 108 %), hydrophobicity (water vapor permeability decreased by 38 %), antibacterial activity (inhibition zone diameters against E. coli and S. aureus were 14.21 mm and 11.83 mm, respectively), antioxidant capacity (increased by 5 to 6 times), and biocompatibility (cell survival rate exceeded 90 %). Grape preservation experiments further confirmed that the CAR film effectively prolongs shelf life. Therefore, CAR film is a promising packaging material for fruit preservation.

The Beneficial Role of Polysaccharide Hydrocolloids in Meat Products: A Review

Polysaccharide hydrocolloids have garnered increasing attention from consumers, experts, and food processing industries due to their advantages of abundant resources, favorable thickening properties, emulsification stability, biocompatibility, biodegradability, and high acceptance as food additives. This review focuses on the application of polysaccharide hydrocolloids and their beneficial roles in meat products by focusing on several commonly used polysaccharides (i.e., cellulose, chitosan, starch, sodium alginate, pectin, and carrageenan). Firstly, the recent advancements of polysaccharide hydrocolloids used in meat products are briefly introduced, along with their structure and potential application prospects. Then, the beneficial roles of polysaccharide hydrocolloids in meat products are comprehensively summarized and highlighted, including retarding lipid and protein oxidation, enhancing nutritional properties, improving texture and color quality, providing antibacterial activity, monitoring freshness, acting as a cryoprotectant, improving printability, and ensuring security. Finally, the challenges and opportunities of polysaccharide hydrocolloids in meat products are also introduced.

Comparative analysis of millet bran nanocelluloses with various morphologies: Revealing differences in the formation mechanism and structure characteristics

To investigate the differences of nanocelluloses with various morphologies, ammonium persulphate (APS) oxidation, H3PO4 dissolution and regeneration, and ball milling combined with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) as a medium were applied to isolate cellulose nanocrystals (MCNCs), cellulose nanospheres (MCNSs) and cellulose fibrils (MCNFs) from millet bran. The structure, properties, and formation mechanism of three nanocelluloses were comparatively investigated by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, atomic force microscope, scanning electronic microscope, and emulsifying ability evaluation. MCNCs had needle-like structures due to the removal of amorphous regions, MCNFs appeared fibrous structures due to swelling and mechanical force, and MCNSs displayed spherical structures through self-assembly. MCNCs and MCNFs were confirmed to exhibit cellulose I structures with crystallinities of 61.24 % and 50.09 %, respectively. MCNSs showed the highest crystallinity of 68.41 % with a cellulose II structure. MCNFs and MCNSs exhibited higher initial decomposition temperatures, while MCNCs showed the highest residual mass. MCNFs suspension showed the highest apparent viscosity, while MCNSs suspension demonstrated superior dispersion. MCNSs-emulsion displayed the smallest droplet size, and MCNFs-emulsion exhibited the highest viscosity. This study reveals the formation mechanisms and relationship between morphologies and properties of three millet bran nanocelluloses, providing a theoretical basis for their application.

Effects and mechanisms of ultrasound-assisted emulsification treatment on the curcumin delivery and digestive properties of myofibrillar protein-carboxymethyl cellulose complex emulsion gel

Different emulsion gel systems are widely applied to deliver functional ingredients. The effects and mechanisms of ultrasound-assisted emulsification (UAE) treatment and carboxymethyl cellulose (CMC) modifying the curcumin delivery properties and in vitro digestibility of the myofibrillar protein (MP)-soybean oil emulsion gels were investigated. The rheological properties, droplet size, protein and CMC distribution, ultrastructure, surface hydrophobicity, sulfhydryl groups, and zeta potential of emulsion gels were also measured. Results indicate that UAE treatment and CMC addition both improved curcumin encapsulation and protection efficiency in MP emulsion gel, especially for the UAE combined with CMC (UAE-CMC) treatment which encapsulation efficiency, protection efficiency, the release rate, and bioaccessibility of curcumin increased from 86.75 % to 97.67 %, 44.85 % to 68.85 %, 18.44 % to 41.78 %, and 28.68 % to 44.93 % respectively. The protein digestibility during the gastric stage was decreased after the CMC addition and UAE treatment, and the protein digestibility during the intestinal stage was reduced after the CMC addition. The fatty acid release rate was increased after CMC addition and UAE treatment. Apparent viscosity, storage modulus, and loss modulus were decreased after CMC addition while increased after UAE and UAE-CMC treatment especially the storage modulus increased from 0.26 Pa to 41 Pa after UAE-CMC treatment. The oil size was decreased, the protein and CMC concentration around the oil was increased, and a denser and uniform emulsion gel network structure was formed after UAE treatment. The surface hydrophobicity, free SH groups, and absolute zeta potential were increased after UAE treatment. The UAE-CMC treatment could strengthen the MP emulsion gel structure and decrease the oil size to increase the curcumin delivery properties, and hydrophobic and electrostatic interaction might be essential forces to maintain the emulsion gel.

Study on the Mechanism of Modified Cellulose Improve the Properties of Egg Yolk gel

Natural fiber is not suitable for modifying yolk gel as a modifier because of its large size and high compactness. In this study, two kinds of modified cellulose were selected to improve the thermal gel properties of yolk. The results showed that the two kinds of cellulose promoted the formation of ordered structure in yolk gel. The ordered gel network not only improved the texture properties and rheological properties, but also improved the water retention of yolk gel significantly. CMC and CNFC at the same concentration, the modification effect of CMC on yolk gel was better than CNFC because of its excellent dispersion. However, high concentration of CNFC (1.20-1.60%) disrupted the cross-linking and ordered structure formation of yolk protein, and the quality of gel was significantly reduced.

Multi-functional nanocellulose based nanocomposites for biodegradable food packaging: Hybridization, fabrication, key properties and application

Nowadays, non-degradable plastic packaging materials have caused serious environmental pollution, posing a threat to human health and development. Renewable eco-friendly nanocellulose hybrid (NCs-hybrid) composites as an ideal alternative to petroleum-based plastic food packaging have been extensively reported in recent years. NCs-hybrids include metal, metal oxides, organic frameworks (MOFs), plants, and active compounds. However, no review systematically summarizes the preparation, processing, and multi-functional applications of NCs-hybrid composites. In this review, the design and hybridization of various NCs-hybrids, the processing of multi-scale nanocomposites, and their key properties in food packaging applications were systematically explored for the first time. Moreover, the synergistic effects of various NCs-hybrids on several properties of composites, including mechanical, thermal, UV shielding, waterproofing, barrier, antimicrobial, antioxidant, biodegradation and sensing were reviewed in detailed. Then, the problems and advances in research on renewable NCs-hybrid composites are suggested for biodegradable food packaging applications. Finally, a future packaging material is proposed by using NCs-hybrids as nanofillers and endowing them with various properties, which are denoted as "PACKAGE" and characterized by "Property, Application, Cellulose, Keen, Antipollution, Green, Easy."

Recent advances on natural colorants-based intelligent colorimetric food freshness indicators: fabrication, multifunctional applications and optimization strategies

With the increasing concerns of food safety and public health, tremendous efforts have been concentrated on the development of effective, reliable, nondestructive methods to evaluate the freshness level of different kinds of food. Natural colorants-based intelligent colorimetric indicators which are typically constructed with natural colorants and polymer matrices has been regarded as an innovative approach to notify the customers and retailers of the food quality during the storage and transportation procedure in real-time. This review briefly elucidates the mechanism of natural colorants used for intelligent colorimetric indicators and fabrication methodologies of natural colorants-based food freshness indicators. Subsequently, their multifunctional applications in intelligent food packaging systems like antioxidant packaging, antimicrobial packaging, biodegradable packaging, UV-blocking packaging and inkless packaging are well introduced. This paper also summarizes several optimizing strategies for the practical application of this advanced technology from different perspectives. Strategies like adopting a hydrophobic matrix, constructing double-layer film and encapsulation have been developed to improve the stability of the indicators. Co-pigmentation, metal ion complexation, pigment-mixing and using substrates with high surface area are proved to be effective to enhance the sensitivity of the indicators. Approaches include multi-index evaluation, machine learning and smartphone-assisted evaluation have been proven to improve the accuracy of the intelligent food freshness indicators. Finally, future research opportunities and challenges are proposed. Based on the fundamental understanding of natural colorants-based intelligent colorimetric food freshness indicators, and the latest research and findings from literature, this review article will help to develop better, lower cost and more reliable food freshness evaluation technique for modern food industry.

Potential biomarkers analysis and protein internal mechanisms by cold plasma treatment: Is proteomics effective to elucidate protein-protein interaction network and biochemical pathway?

New market trends of meat flavor, tenderness, and color quality indicators have prompted the research on meat preservation as a crucial topic to received attention. Present research about the effects of irradiation, cold plasma technology on meat is incomplete. There are strongly recommended that proteomics techniques be jointly to enhance the coverage of internal meat molecules for meat research. By identifying meat proteins, detecting biological functions, and quantifying the protein segments of specific meat biomarkers, which can be provided for the information of diagnostic components in preservative technologies. The current review provides scientific findings on various control strategies: (i) combine the data-independent acquisition to provide a reference for the meat molecular mechanism and rapid identification; (ii) design molecular networks biological functions assessment model; (iii) molecular investigations of cold plasma techniques and underlying mechanisms; (iv) explore the X-rays and γ-rays treatment in meat preservation and myoglobin change mechanism more comprehensively.

Effects of carboxymethyl cellulose on the emulsifying, gel and digestive properties of myofibrillar protein-soybean oil emulsion

Improving the qualities of vegetable oil replaced animal fat meat products is particularly fascinating for the development of healthy meat products. This work was designed to investigate the effects of different carboxymethyl cellulose (CMC) concentrations (0.01 %, 0.05 %, 0.1 %, 0.2 %, and 0.5 %) on the emulsifying, gelation, and digestive properties of myofibrillar protein (MP)-soybean oil emulsions. The changes in MP emulsion characteristics, gelation properties, protein digestibility, and oil release rate were determined. Results demonstrated that CMC addition decreased the average droplet size and increased the apparent viscosity, storage modulus, and loss modulus of MP emulsions, and a 0.5 % CMC addition significantly increased the storage stability during 6 weeks. Lower CMC addition (0.01 % to 0.1 %) increased the hardness, chewiness, and gumminess of emulsion gel especially for the 0.1 % CMC addition, while higher CMC (0.5 %) content decreased the texture properties and water holding capacity of emulsion gels. The addition of CMC decreased protein digestibility during the gastric stage, and 0.01 % and 0.05 % CMC addition significantly decreased the free fatty acid release rate. In summary, the addition of CMC could improve the stability of MP emulsion and the texture properties of the emulsion gels, and decrease protein digestibility during the gastric stage.

Dried Vegetables as Potential Clean-Label Phosphate Substitutes in Cooked Sausage Meat

While phosphates are key additives in sausage production, their use conflicts with consumer preferences for "natural" foods. In this study, we investigated the potential of using vegetables as "clean-label" phosphate substitutes and their effects on water holding capacity, consumer acceptance, color, softness, and tenderness. Six freeze-dried vegetables with a pH above 6.0 were added to sausage meat on a laboratory scale. Adding 1.6% freeze-dried Brussels sprouts or Red Kuri squash resulted in a similar weight gain (7.0%) as the positive control of 0.6% commercial phosphate additive. Higher vegetable concentrations (2.2-4.0%) caused a significant increase in weight (p ≤ 0.05, 10.4-18.4% weight gain). Similar stress was needed to compress sausages containing 1.6/4.0% Brussels sprouts (14.2/11.2 kPa) and the positive control (13.2 kPa). Indentation tests also led to similar softness results for the sausages prepared with 1.6/4.0% Brussels sprouts (15.5 kPa/16.6 kPa) and the positive control (16.5 kPa). A force of 1.25 N was needed to shear the positive control, while 1.60 N/1.30 N was needed for the samples (1.6/4% Brussels sprouts). In summary, the present study indicates that freeze-dried vegetables have the potential to effectively replace phosphate in meat products.

Synergistic effects of psyllium husk powder and different levels of methylcellulose on the storage stability of sodium caseinate emulsion

The study investigated the effects of compound fibers composed of psyllium husk powder (PHP, 0.3%) and methylcellulose (MC, 0, 0.3, 0.6, 0.9, and 1.2%) on the storage stability, rheology, and microstructure of sodium caseinate emulsions. Results showed that the emulsion stability was enhanced with the increased concentrations of MC, especially at the concentration of 1.2%. The oil droplet size in the emulsions was decreased as the concentrations of compound fibers increased, which was further confirmed by the optical microscope analysis. The rheological measurements and cryo-scanning electron microscopy results indicated that compound fibers improved the viscosity of the emulsions, and formed a strong three-dimensional network structure. The results of confocal laser scanning microscope and surface protein concentration measurements showed that compound fibers were evenly distributed into the oil droplet surface. The above results demonstrate that compound fibers are an effective thickener and emulsifier in enhancing the stability properties of oil-in-water (O/W) emulsions stabilized by sodium caseinate.

Antimicrobial Active Packaging Containing Nisin for Preservation of Products of Animal Origin: An Overview

The preservation of food represents one of the greatest challenges in the food industry. Active packaging materials are obtained through the incorporation of antimicrobial and/or antioxidant compounds in order to improve their functionality. Further, these materials are used for food packaging applications for shelf-life extension and fulfilling consumer demands for minimal processed foods with great quality and safety. The incorporation of antimicrobial peptides, such as nisin, has been studied lately, with a great interest applied to the food industry. Antimicrobials can be incorporated in various matrices such as nanofibers, nanoemulsions, nanoliposomes, or nanoparticles, which are further used for packaging. Despite the widespread application of nisin as an antimicrobial by directly incorporating it into various foods, the use of nisin by incorporating it into food packaging materials is researched at a much smaller scale. The researchers in this field are still in full development, being specific to the type of product studied. The purpose of this study was to present recent results obtained as a result of using nisin as an antimicrobial agent in food packaging materials, with a focus on applications on products of animal origin. The findings showed that nisin incorporated in packaging materials led to a significant reduction in the bacterial load (the total viable count or inoculated strains), maintained product attributes (physical, chemical, and sensorial), and prolonged their shelf-life.

Gel-type emulsified muscle products: Mechanisms, affecting factors, and applications

The gel-type emulsified muscle products improve fatty acid composition, maintain the oxidative stability, and achieve a better sensory acceptability. This review emphasizes the stabilization mechanisms of these emulsified muscle products. In particular, factors associated with the stability of the emulsified muscle systems are outlined, including the processing conditions (pH and heating), lipids, and emulsifiers. Besides, some novel systems are further introduced, including the Pickering emulsions and organogels, due to their great potential in stabilizing emulsified gels. Moreover, the promising prospects of emulsion muscle products such as improved gel properties, oxidative stability, freeze-thaw stability, fat replacement, and nutraceutical encapsulation were elaborated. This review comprehensively illustrates the considerations on developing gel-type emulsified products and provides inspiration for the rational design of emulsified muscle formulations with both oxidatively stable and organoleptically acceptable performance.

Prospects for the next generation of artificial enzymes for ensuring the quality of chilled meat: Opportunities and challenges

As living standards rise, the demand for high-quality chilled meat among consumers also grows. Researchers and enterprises have been interested in ensuring the quality of chilled meat in all links of the downstream industry. Nanozyme has shown the potential to address the aforementioned requirements. Reasons and approaches for the application of nanozymes in the freshness assessment or shelf life extension of chilled meat were discussed. The challenges for applying these nanozymes to ensure the quality of chilled meat were also summarized. Finally, this review examined the safety, regulatory status, and consumer attitudes toward nanozymes. This review revealed that the freshness assessment of chilled meat is closely related to mimicking the enzyme activities of nanozymes, whereas the shelf life changes of chilled meat are mostly dependent on the photothermal activities and pseudophotodynamic activities of nanozymes. In contrast, studies regarding the shelf life of chilled meat are more challenging to develop, as excessive heat or reactive oxygen species impair its quality. Notably, meat contains a complex matrix composition that may interact with the nanozyme, reducing its effectiveness. Nanopollution and mass manufacturing are additional obstacles that must be overcome. Therefore, it is vital to choose suitable approaches to ensure meat quality. Furthermore, the safety of nanozymes in meat applications still needs careful consideration owing to their widespread usage.

Main animal fat replacers for the manufacture of healthy processed meat products

The technological, sensory, and nutritional characteristics of meat products are directly related to their animal fat content. Adding animal fat to meat products significantly influences their sensory properties, such as color, taste, and aroma. In addition, the physicochemical properties of fat decisively contribute to the texture of meat products, playing a fundamental role in improving the properties of viscosity, creaminess, chewiness, cohesiveness, and hardness. However, meat products' high animal fat content makes them detrimental to a healthy diet. Therefore, reducing the fat content of meat products is an urgent need, but it is a challenge for researchers and the meat industry. The fat reduction in meat products without compromising the product's quality and with minor impacts on the production costs is not a simple task. Thus, strategies to reduce the fat content of meat products should be studied with caution. During the last decades, several fat replacers were tested, but among all of them, the use of flours and fibers, hydrocolloids, mushrooms, and some animal proteins (such as whey and collagen) presented promising results. Additionally, multiple strategies to gel oils of vegetable origin are also a current topic of study, and these have certain advantages such as their appearance (attempts to imitate animal fat), while also improving the nutritional profile of the lipid fraction of the products meat. However, each of these fat substitutes has both advantages and limitations in their use, which will be discussed in subsequent sections. Therefore, due to the growing interest in this issue, this review focuses on the main substitutes for animal fat used in the production of meat products, offering detailed and updated information on the latest discoveries and advances in this area.

Effect of Malondialdehyde on the Digestibility of Beef Myofibrillar Protein: Potential Mechanisms from Structure to Modification Site

Lipid oxidation and protein oxidation occur side by side in meat. Here, the effect of malondialdehyde (MDA), the major product of lipid oxidation, on the digestibility of beef myofibrillar proteins (MP) was studied. MP samples were incubated with 0, 0.1, 0.3, 0.5, and 0.7 mM MDA at 4 °C for 12 h and then subjected to in vitro gastrointestinal digestion. The result showed that MDA remarkably reduced the digestibility of MP (p < 0.05). MDA treatments significantly increased carbonyl and Schiff base contents in MP (p < 0.05). The microstructure observed by atomic force microscopy showed that MDA treatments resulted in the aggregation of MP. Non-reducing and reducing electrophoresis suggested the aggregation was mainly caused by covalent bonds including disulfide bond and carbonyl−amine bond. Proteomics analysis proved that the myosin tail was the main target of MDA attack, meanwhile, lysine residues were the major modification sites. Taken together, the above results imply that MDA induces protein oxidation, aggregation, and blockage of hydrolysis sites, consequently leading to the decrease in both gastric and gastrointestinal digestibility of MP.