Quality Of Meat Products Research Articles

Isotachophoretic quantification of total viable bacteria on meat and surfaces

BackgroundThe quantification of microbes, particularly live bacteria, is of utmost importance in assessing the quality of meat products. In the context of meat processing facilities, prompt identification and removal of contaminated carcasses or surfaces is crucial to ensuring the continuous production of safe meat for human consumption. The plate count method and other traditional detection methods are not only labour-intensive but also time-consuming taking 24–48 h. ResultsIn this report, we present a novel isotachophoretic quantification method utilizing two nucleic acid stains, SYTO9 and propionic iodide, for the detection of total viable bacteria. The study employed E. coli M23 bacteria as a model organism, with an analysis time of only 30 min. The method demonstrated a limit of detection (LOD) of 184 CFU mL−1 and 14 cells mL−1 for total viable count and total cell count, respectively. Furthermore, this new approach is capable of detecting the microbial quality standard limits for food contacting surfaces (10 CFU cm−2) and meat (1.99 × 104 CFU cm−2) by swabbing an area of 10 × 10 cm2. SignificanceIn contrast to the culture-based methods usually employed in food processing facilities, this isotachophoretic technique enables easy and rapid detection (<30 min) of microorganisms, facilitating crucial decision-making essential for maintaining product quality and safety.

Optimization of sodium alginate, taro starch and lactic acid based biodegradable films: Antimicrobial effect on a meat product

Sustainable biodegradable polymer films represent a key response to environmental concerns and food preservation. This study employed response surface methodology (RSM) through a Box-Behnken design, considering three factors sodium alginate (ALG) (0.75–1.5 % w/v), glycerol (G) (0.5–1 % w/v), and lactic acid (LA) (1-3 % v/v), to obtain an optimized biodegradable film (OBF) of taro starch (TAS). The resulting optimal composition was 1.04 % w/v ALG, 0.75 % w/v G, and 1.25 % v/v LA, with a thickness of 0.14 mm and a WVP of 1.05 g·mm/kPa·h·m2. The LA in OBF increased elongation by 23.24 % and demonstrated inhibition areas exceeding 5.00 cm2 against E. coli and L. monocytogenes. FTIR and SEM analysis confirmed the covalent cross-linking between TAS-LA and revealed compatibility among matrix materials. OBF was employed as an active packaging system (T3) in a Spanish chorizo-type meat product to evaluate its physicochemical and microbiological properties. The most significant changes (humidity, weight loss, aw, pH, acidity, hardness) occurred within the first nine days. T3 inhibited the growth of coliforms and reduced populations of mesophiles and lactic acid bacteria by ∼1 log cycle. OBF guarantees meat product quality and microbial properties while supporting sustainable practices through environmentally respectful biodegradation.

Potential of Paulownia Leaves Silage in Lamb Diet to Improve Ruminal Fermentation and Fatty Acid Profile − An in vitro Study

Abstract Environmental impact, quality, and quantity of food products of ruminant origin (especially beef and mutton) are considered major challenges in meeting the nutritional requirements of the growing human population worldwide. Therefore, we conducted this in vitro study to explore the potential of Paulownia leaves silage to reduce the environmental impact of feedlot lamb production and improve ruminal fatty acids (FAs) profile by influencing ruminal biohydrogenation. In the present study, Paulownia leaves silage (PLS) and alfalfa silage (AAS) were mixed in a proportion of 1:0 (Control, PLS 0%), 0.75:0.25 (PLS 25%), 0.5:0.5 (PLS 50%), 0.25:0.75 (PLS 75%) and 0:1 (PLS 100%) on dry matter basis in the lamb diet. The experimental findings demonstrated that 100% replacement of AAS with PLS in the lamb diet significantly improved the ruminal fermentation by increasing the in vitro DM degradability (P&lt;0.01), total volatile fatty acid (P&lt;0.01), and propionate production (P&lt;0.01) while reducing the acetate: propionate (A/P) ratio (P&lt;0.01) and CH4 concentration (mM; L and Q P&lt;0.05) and CH4 production, mM/g DM (L and Q P&lt;0.05). Meanwhile, 100% PLS inclusion in the diet increased the total monounsaturated fatty acids (P&lt;0.05), total unsaturated fatty acids (P&lt;0.01) and total n-3 fatty acids (P&lt;0.05) particularly alpha-linolenic acid (ALA; C18:3 n-3; P&lt;0.05) in the rumen fluid after incubation. Moreover, the total saturated fatty acids concentration was reduced (P&lt;0.01). These findings suggested that PLS could be a climate-friendly and sustainable alternative to AAS in the lamb feedlot diet for quality meat production.

Association study between SNP markers located in meat quality candidate genes with intramuscular fat content in an endangered dual-purpose cattle population.

The aim of this study was to associate single nucleotide polymorphisms (SNP) of the bovine calcium-activated neutral protease µ-calpain, calpastatin, diacylglycerol-O-acyltransferase, adipose fatty acid binding protein, retinoic acid receptor-related orphan receptor C (RORC), and thyroglobulin (TG) gene with intramuscular fat content (IMF). Therefore, 542 animals of the cattle breed "Rotes Höhenvieh" (RHV) were phenotyped for IMF. Genotyping of the animals was performed using polymerase chain reaction-restriction fragment length polymorphism tests for six SNP from candidate genes for meat quality traits. In addition, we calculated allele substitution and dominance effects on IMF. A subgroup of animals (n = 44, reduced dataset) with extraordinary high IMF was analyzed separately. The mean IMF content was 2.5% (SD: 2.8) but ranged from 0.02% to 23.9%, underlining the breeds' potential for quality meat production. Allele and genotype frequencies for all SNP were similar in the complete and reduced dataset. Association analyses in the complete dataset revealed the strongest effects of RORC on IMF (P = 0.075). The log-transformed least-squares mean for IMF of genotype g.3290GG was 0.45 ± 0.16, 0.26 ± 0.14 for genotype g.3290GT, and 0.32 ± 0.14 for genotype g.3290TT. In the reduced dataset, we found a significant effect (P < 0.05) of the g.422C>T-SNP of TG on IMF, with highest IMF for genotype CT (0.91 ± 0.17), lowest IMF for genotype TT (0.37 ± 0.25), and medium IMF for genotype CC (0.59 ± 0.16; log-transformed values). Compared to the complete dataset, allele substitution effects increased in the reduced dataset for most of the SNP, possibly due to the selective genotyping strategy, with focus on animals with highest IMF implying strong phenotypic IMF contrast. Dominance effects were small in both datasets, related to the high heritability of IMF. Results indicated RHV breed particularities regarding the effects of meat quality genes on IMF. An explanation might be the breeding history of RHV with focus on adaptation and resilience in harsh outdoor systems. Consequently, it is imperative to develop breed-specific selection strategies. Allele substitution and dominance effects were in a similar direction in both datasets, suggesting the same breeding approaches for different RHV strains in different regions. Nevertheless, a selective genotyping approach (reduced dataset), contributed to more pronounced genotype effect differences on IMF and dominance values.

한우의 체외수정란으로 생산된 육우의 경제성

This study seeks to compare the economic feasibility and slaughter weight of beef cattle produced based on in vitro embryo. To this end, the study compared and investigated the grade rate of carcasses based on embryo transfer and artificial insemination; slaughter weight, carcass grading results, meat quality and quantity. With respect to the meat grades of carcass based on embryo transfer and artificial insemination; 50.0% (5/10) of embryo transfer-based carcasses were graded with 1++; and 50.0% (5/10), 1+, indicating that 100% (10/10) received at least 1+ grade. On the other hand, artificial insemination-based castrated cattle had no 1++ grade while 30.0% (6/20) received 1+; 60.0% (12/20), 1; and 10.0% (2/20) 2. This finding showed that embryo-based castrated cattle had higher grades than artificial insemination-based cattle as 100% of the former were graded with 1+ or higher. This study also investigated 10 embryo transfer-based castrated cattle and 20 artificial insemination-based cattle to compare their dressed weight, back fat thickness, sirloin cross section, and meat quantity indication. As a result, the embryo transfer-based castrated cattle showed slaughter weight of 488.4kg on average, heavier by 40.6kg than 447.8kg of artificial insemination-based cattle. Back fat thickness was 15.6㎝ on average in embryo transfer-based cases, 0.9㎝ thinner than 16.5㎝ of artificial insemination-based cases. Sirloin cross section of embryo transfer-based cattle was 99.6㎠ on average, 9.8㎠ wider than 89.8㎠ of artificial insemination cases. Meat quantity indication was found 2.1% higher in the embryo transfer cases (62.8%) than artificial insemination cases (64.9%). With respect to meat quantity grade, 10.0% (2/20) of the artificial insemination cases had Grade A; 50.0% (10/20), Grade B; and 40.0% (8/20), Grade C. Embryo transfer-based cattle showed no Grade A among the 10 carcasses; Grade B in 60.0% (6/10); and Grade C in 40.0% (4/10). Comparing the results of economic profitability in terms of carcass auction prices, the embryo transfer-based castrated cattle was KRW 1,119,453 higher than artificial insemination-based castrated case. Per-head economic gain of embryo transfer-based castrated cattle was KRW 2,282,602, higher than KRW 1,567,149 of artificial insemination-based cattle. Based on the findings, this study examined embryo transfer-based castrated cattle and artificial insemination-based cattle to compare their carcass grade rate, dressed weight, grading result and economic feasibility. Consequentially, this study found that in vitro embryo transfer-based castrated cattle had higher meat quality grade, slaughter weight and economic feasibility. Based on information on pedigree, attribute, and carcass data of individual with blood tie which indicate such meat productivity; high grade cattle genetic resources would be secured to contribute to quality meat production. Subsequent study will need to research industrialization based on in vitro embryo transfer.

Подходы к проектированию рецептур мясных продуктов с заданными показателями качества

A profitable meat-processing business relies on the rational use of its resources, which, in its turn, depends on the constant improvement of product formulations and development of new ones. These operations involve advanced analytical methods and complex approaches. The article introduces a review of modern technical solutions, methods, and approaches to modeling new complex meat products with preset quality indicators.&#x0D; The review (1990–2022) involved research articles published in high-rated peer-reviewed research journals, educational literature, digital theses published by Russian Dissertation Councils, and patents registered by the Institute of Industrial Property. &#x0D; The synchronic and diachronic analysis of basic principles of food product design and parametric modeling revealed no universal methodology for meat products development, both in terms of goals and applicability to different meat products types. Forecasting of finished meat products quality indicators requires relevant and accurate information, which is highly variable and fast-changing. Unfortunately, advanced information technologies are slow to adapt to the urgent tasks of the food industry. &#x0D; As a result, the current methods for developing new complex meat product formulations are useless when meat producers have no access to relevant and self-updating databases on raw m aterials properties.

SAFETY OF MILK AND MEAT PRODUCTS IN THE RUSSIAN FEDERATION IN DYNAMICS: RESULTS OF SANITARY-EPIDEMIOLOGICAL CONTROL (2013-2022)

Background. The study addresses an extremely important issue, namely quality and safety of meat and milk products that are consumed daily by majority of the population in the Russian Federation.&#x0D; Aim. To investigate safety of animal food products (meat and milk products) in dynamics.&#x0D; Materials and methods. We performed retrospective analysis of the branch statistical report with the results of control (surveillance) over milk and meat products obtained in the period between 2013 and 2022. We estimated safety levels in dynamics and spatial distribution of shares of unsafe goods as per priority indicators.&#x0D; Results. Frequency of cases when mandatory requirements to safety of milk and meat products were violated amounted to 4.0 % and approximately 3.0 % accordingly. Hygienic requirements were most frequently violated as per microbiological and physical-chemical indicators, 3.84 % and 2.69 % accordingly for meat products and 4.2 % and 6.0 % accordingly for milk products. We analyzed safety of meat products in dynamics and established positive trends to be rather weak and multidirectional as per different indicators; as for milk products, shares of unsafe products went down as per all the standardized indicators except from sanitary-chemical ones. &#x0D; Conclusion. Our study didn’t reveal any obvious positive dynamics (descending trends) in the shares of food product samples deviating from the safety standards. This means it is necessary to improve the current system for control (surveillance) over meat and milk products. More effective control (surveillance) can be provided by creating ‘risk profiles’ of a product with information about the most risky indicators to describe hazards associated with it. These indicators should be the first to be included into programs of product laboratory testing. In addition, it is vital to create regional registers of food products assigned into specific categories as per associated health risks. Such registers can also be used to select groups and types of products that should be covered by surveillance. The development of the risk-based surveillance can facilitate elimination of low quality and unsafe food products form the market.

Review on the Economic Impacts of Lumpy Skin Disease of Cattle and Its Prevention and Control Strategies in Ethiopia

Lumpy skin disease (LSD) is an infectious disease of cattle, caused by a Lumpy Skin Disease Virus. It is an economically important viral disease of cattle affecting all ages and breeds that can be prevented by vaccination in endemic regions including Ethiopia. LSD is an OIE listed disease because of considerable financial losses and in Ethiopia due to the endemic nature of LSD; the country is facing serious difficulties in exporting live cattle and their products. In addition, this situation contributes a negative impact on the national economic growth through the loss of meat and milk production and poor quality of skin and hides. Serious economic losses can follow outbreaks that have a high morbidity and high mortality rates of 40 percent or more have been encountered. There is no specific antiviral treatment available for LSD-infected cattle. The disease is now the problem of almost all the regions and agro ecological zones of Ethiopia. Major outbreaks of LSD have been occurred in different regions of Ethiopia. Two vaccines, however, Neethling and Kenya sheep and goat pox virus, have been used widely in Africa with success. Preventing movement the diseased animals along with vector control, regular annual vaccinations and awareness creation for cattle owners play great role in disease prevention and control. The disease outbreak was observed in the cattle regardless of previous vaccination with Kenyan sheep- and goat pox vaccine the occurrence of LSD outbreak scale, despite the use of a vaccination regime, is suggestive of vaccine failure. Apparent emerging vaccine failure is a serious problem for efficient control of LSD, as the disease has been manifested by high morbidity and mortality rates, regardless of vaccination status. Consequently continuous surveillance on the status of the disease and genetic information on circulating field viruses is mandatory in order to take effective measures for the control of the disease in the country.

The effect of ultrasound on the quality indicators of food raw materials and finished products

The article presents the results of a study of the effect of ultrasonic treatment on changes in the quality of meat.In most of the previous studies on the use of ultrasonic treatment, a positive effect on the quality of meat and meat products was noted. Ultrasonic processing is widespread in accelerating technological processes, improving the functional, technological and structural and mechanical properties of meat.In the course of these studies, meat samples of various animal species were subjected to ultrasound exposure of various durations, after which changes in shear stress, moisture binding capacity and microbiological parameters of pork, beef, mutton and horse meat were determined. As a result, ultrasonic processing has reduced the stress of cutting all types of meat. The optimal duration of ultrasonic treatment has been determined, which increases the moisture binding capacity of meat. As the duration of ultrasonic treatment increased, a decrease in the number of pathogenic microorganisms in meat was observed.Based on the results of these studies, it was concluded that ultrasonic treatment is important for the meat industry, since this method can be used as a non-thermal effect to improve physical, biochemical and microbiological characteristics that increase the quality, safety and increase the shelf life of various meat products.

STUDY OF THE EFFECT OF PROTEIN-VITAMIN-MINERAL FEED ADDITIVES ON THE INCREASE IN LIVE WEIGHT OF HORSES

Agriculture is considered an important industry for Kazakhstan. Consumer demand for livestock products (beef and dairy cattle) is very high. Protein-vitamin feed additives are of great importance in the breeding of meat and dairy animals. Feed additives not only increase live weight gain, but also strengthen the immunity of animals and increase resistance to adverse environmental factors. The article discusses the results of experimental studies on the influence of a feed additive of a new composition on the physiological condition of horses on the yield and quality of meat products. As an obyect, horses of the Kazakh breed aged 1.5-2.0 years were selected, that located in the stall. Based on the study of blood composition, an increase in the values ​​of erythrocytes, hemoglobin, leukocytes and platelets was revealed in the experimental groups of horses taking the feed additives, compared with the animals of the control group. This indicates the activation of immunity and the improvement of protein-carbohydrate metabolism in horses of the experimental groups. The purpose of the research work is to study the effect of a protein vitamin mineral feed additive on the meat and productivity of horses. This feed additive allows you to expand the range of feed additives that increase the live weight gain of farm animals.&#x0D;

Improvement of meat product traceability system using digital technologies

This research work addresses the issue of enhancing the effectiveness of the meat product traceability system using modern digital technologies. In the context of increasing demand for food safety and minimizing risks to consumer health, ensuring accurate and reliable traceability of the origin, production conditions, and storage of meat products has become a crucial aspect. The aim of the study is to create an integration between the meat product traceability system and contemporary digital technologies. During the work, an analysis of existing problems and shortcomings in the current traceability system is planned, as well as an exploration of experiences from other industries where digital technologies have been successfully implemented to ensure transparency and data authenticity. In analyzing technological risks, all possible types of threats were considered. The sources of danger include incoming raw materials, the technological line of semi-smoked sausages, and their storage. The use of digital technologies allows for continuous data monitoring using Wi-Fi, combined thermometers, and quality logs. It is anticipated that the implementation of such a system will significantly reduce risks, improve product tracking, and enhance consumer trust in the quality and safety of meat products. The outcomes of this research will be valuable for food industry enterprises, regulatory bodies, and the scientific community that are striving to improve the control and traceability system of food products, utilizing cutting-edge digital innovations.

Hydrolytic and antioxidant activities of pork loin protein hydrolysates treated with various freeze‐dried kiwifruit powders during incubation

SummaryThis study aimed to evaluate the protease activity of freeze‐dried kiwifruits as affected by the various colours and the antioxidant activities of protein hydrolysates from pork loin protein (sarcoplasmic and myofibrillar proteins) containing different freeze‐dried kiwifruit powder during incubation times. The protease activity of freeze‐dried kiwifruit powders was determined using casein and meat protein as substrates. Gold and green kiwifruit powders showed higher protease activity than red kiwifruit powders. Each type of kiwifruit showed different hydrolysis degrees for myofibrillar and sarcoplasmic proteins. The myofibrillar and sarcoplasmic proteins with kiwifruit powder showed increased antioxidant activity compared to the control. The protein hydrolysates obtained from pork loins treated with green and gold kiwifruit powders increased antioxidant activity with increased incubation time. These results suggested that the protein hydrolysates of pork loins containing freeze‐dried kiwifruit powders had potential antioxidant activity, resulting in maintaining meat product quality during storage.

Polymorphism within IGFBP Genes Affects the Acidity, Colour, and Shear Force of Rabbit Meat

Rabbits are important livestock animals, popular for their nutritional value. Nowadays, the molecular background of traits influencing the quality of meat and meat products is in high demand. Therefore, in the current study, we analyse the sequences of IGFBP1, IGFBP2, IGFBP4, IGFBP5, and IGFBP6 for possible polymorphisms. Based on a bioinformatics analysis in an association study on 466 animals of different breeds (New Zealand White × Flemish Giant crossbreed (9NZWxFG), Termond White (TW), Popielno White (PW), and Flemish Giant (FG)), we analyse the influence of five polymorphisms within the IGFBP genes. Statistically significant differences were found among the carcass and meat quality traits but not for all of the analysed rabbit breeds. The most promising polymorphism was g.158093018A&gt;T within the IGFBP5 gene. The values of pH24 of m.longissimus lumborum (m.l.l.) and biceps femoris muscles (m.b.f.) were higher for the AT genotypes compared to the AA genotypes for the TW and NZWxFG crossbreeds. Also, for pH24, we found differences in ing.41594308T&gt;C for NZWxFG, where the TT genotype values were higher than the TC values. We found differences in L*24 on m.l.l. for g.41592248A&gt;C for NZWxFG. For m.b.f., significant differences were found in b*45 for g.3431insAC in the FG population and a*45 for g.41592248A&gt;C and g.158093018A&gt;T in the TW population. The shear force statistically differed for g.158093018A&gt;T in TW rabbits and g.41592248A&gt;C for NZWxFG. We conclude that this polymorphism may be promising for better quality rabbit meat and may be implemented in selection processes.

Effect of vermiculite feed additive on the chemical, mineral, and amino acid compositions of quail meat.

Poultry farming plays a significant role in providing the population with high-quality and cheap meat products. The development and success of this industry depend on the proper use of available feed. As a rule, feed additives should compensate for missing elements in livestock diets. This study investigated the effects of vermiculite feed additives on the chemical, amino acid, and mineral compositions of quail meat. Texas Quail meat breed birds were randomly divided into three groups (35 heads each). Group I served as the control group, in which the birds were fed a standard diet without any supplements. The diet of Group II was supplemented with 3% vermiculite feed additive, whereas Group III received 5% vermiculite. The experiment was conducted over 120 days. Quails in the experimental groups contained less moisture, had more ash and protein, and were richer in calories in terms of energy value. In terms of mineral composition, the calcium concentrations were 9.9% and 16.5% higher in the in the Group I and II, respectively. Furthermore, the highest percentages of nonessential and essential amino acids were found in the 5% vermiculite group. In the meat of quails that received 5% vermiculite, cadmium and lead salt levels were 20%-25% lower than those in the control variant. The results of our analyses confirmed that meeting the mineral requirements of quails improves animal productivity and meat product quality. Vermiculite as a feed additive improved the chemical, mineral, and amino acid compositions of quail meat when it was added to up to 5% of the feed dry matter. These results will help to improve the feed base of the poultry industry in the Republic of Kazakhstan.

ВЛИЯНИЕ НЕТРАДИЦИОННЫХ РАСТИТЕЛЬНЫХ КОМПОНЕНТОВ НА ХРАНИМОСПОСОБНОСТЬ ЖАРЕНЫХ КОЛБАСНЫХ ИЗДЕЛИЙ

The article presents the results of studying the possibility of combined use of chickpea extrudate and herbal substances in the recipe for fried sausage: dried lovage and fennel seeds to obtain the preservation and organoleptic qualities of meat products. The prototype for the samples designed was the generally accepted fried sausage "Ukraiskaya" production technology. As part of the work, the obtaining technology was developed and optimal dose of the studied herbal ingredients was determined, which allowed to obtain high organoleptic indicators. The prototypes had a spicy taste, brown color on the cut, elastic consistency, pleasant aroma typical of this type of product. The positive effect of the studied herbal supplements on the dynamics of changes in indicators: total number of mesophilic aerobic and facultative anaerobic microorganisms, acid number of fat and oxidative stability of fat was established. Storing the samples for 15 days at a temperature of (4 ± 2) ° C and relative humidity (75 ± 5)%, revealed that these indicators were within the norm for this type of meat products. Finished product yeild of sample №1 exceeded this indicator in the control sample by 7%, and in the case of samples №2 and №3 – by 6% (78% and 77%, respectively), which can be interpret by the protein-carbohydrate complexes formation when chickpea extrudate is added to the product, reducing the amount of free moisture in the meat system. The developed recipes of fried sausages make it possible to fortify and diversify the diet of consumers. There are no analogues in the modern sausage market, which is an integral advantage in the product sale.

Combining Feature Selection Techniques and Neurofuzzy Systems for the Prediction of Total Viable Counts in Beef Fillets Using Multispectral Imaging

In the food industry, quality and safety issues are associated with consumers’ health condition. There is a growing interest in applying various noninvasive sensorial techniques to obtain quickly quality attributes. One of them, hyperspectral/multispectral imaging technique has been extensively used for inspection of various food products. In this paper, a stacking-based ensemble prediction system has been developed for the prediction of total viable counts of microorganisms in beef fillet samples, an essential cause to meat spoilage, utilizing multispectral imaging information. As the selection of important wavelengths from the multispectral imaging system is considered as an essential stage to the prediction scheme, a features fusion approach has been also explored, by combining wavelengths extracted from various feature selection techniques. Ensemble sub-components include two advanced clustering-based neuro-fuzzy network prediction models, one utilizing information from average reflectance values, while the other one from the standard deviation of the pixels’ intensity per wavelength. The performances of neurofuzzy models were compared against established regression algorithms such as multilayer perceptron, support vector machines and partial least squares. Obtained results confirmed the validity of the proposed hypothesis to utilize a combination of feature selection methods with neurofuzzy models in order to assess the microbiological quality of meat products.

Identification of Protein-Phenol Adducts in Meat Proteins: A Molecular Probe Technology Study.

Plant polyphenols with a catechol structure can form covalent adducts with meat proteins, which affects the quality and processing of meat products. However, there is a lack of fast and effective methods of characterizing these adducts and understanding their mechanisms. This study aimed to investigate the covalent interaction between myofibrillar protein (MP) and caffeic acid (CA), a plant polyphenol with a catechol structure, using molecular probe technology. The CA-MP adducts were separated via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and detected via Western blot and LC-MS/MS analyses. The Western blot analysis revealed that various specific adducts were successfully enriched and identified as bands around 220 kDa, 45 kDa, and two distinct bands between 95 and 130 kDa. Combined with the LC-MS/MS analysis, a total of 51 peptides were identified to be CA-adducted, corresponding to 31 proteins. More than 80% of the adducted peptides carried one adducted site, and the rest carried two adducted sites. The adducted sites were located on cysteine (C/Cys), histidine (H/His), arginine (R/Arg), lysine (K/Lys), proline (P/Pro), and N-terminal (N-Term) residues. Results showed that the covalent interaction of CA and MP was highly selective for the R side chain of amino acids. Moreover, the adducts were more likely to form via C-N bonding than C-S bonding. This study provides new insights into the covalent interaction of plant polyphenols and meat proteins, which has important implications for the rational use of plant polyphenols in the meat processing industry.

Study on the interaction and gel properties of pork myofibrillar protein with konjac polysaccharides.

Natural myofibrillar protein (MP) is sensitive to changes in the microenvironment, such as pH and ionic strength, and therefore can adversely affect the final quality of meat products. The aim of this study was to modify natural MP as well as to improve its functional properties. Therefore, the quality improvement effect of konjac polysaccharides with different concentrations (0, 1.5, 3, 4.5 and 6 g kg-1 protein) on MP gels was investigated. With a concentration of konjac polysaccharides of 6 g kg-1 protein, the composite gel obtained exhibited a significant improvement of water binding (water holding capacity increased by 7.71%) and textural performance (strength increased from 29.12 to 37.55 N mm, an increase of 8.43 N mm). Meanwhile, konjac polysaccharides could help to form more disulfide bonds and non-disulfide covalent bonds, which enhanced the crosslinking of MP and maintained the MP gel network structure. Then, with the preservation of α-helix structure (a significant increase of 8.11%), slower protein aggregation and formation of small aggregates, this supported the formation of a fine and homogeneous network structure and allowed a reduction in water mobility. During the heating process, konjac polysaccharides could absorb the surrounding water and fill the gel system, which resulted in an increase in the water content of the gel network and enhanced the gel-forming ability of the gel. Meanwhile, konjac polysaccharides might inhibit irregular aggregation of proteins and promote the formation of small aggregates, which in turn form a homogeneous and continuous gel matrix by orderly arrangement. © 2023 Society of Chemical Industry.

Improvement of gelation properties of Penaeus vannamei surimi by magnetic field-assisted freezing in combination with curdlan

Traditional methods of freezing and thawing may harm the quality of meat products. In order to reduce the negative impact of freezing on surimi products, the magnetic field-assisted freezing method is combined with various curdlan ratios to enhance the gelation characteristics of Penaeus vannamei surimi in this study. The results showed that the magnetic field-assisted freezing technique significantly improved the quality of thawed surimi compared with soaking freezing (SF), whereas the addition of curdlan further improved the gelation properties, and the gel strength, water-holding capacity, textural properties, whiteness, and G′ value were significantly improved when its content was increased to 0.6 %. However, excessive amounts of curdlan interfered with protein covalent cross-linking, leading to a decrease in gel quality. Additionally, the addition of magnetic field and curdlan encouraged the shift of the α-helix to the random coil and β-sheet transition, which stimulated the growth of myofibril molecules, exposed the hydrophobic groups and thiols, improved protein-molecule interactions, and promoted systematic gathering of proteins, leading to the formation of the microstructure of dense and small pores. It also resulted in a drop in water release, an increase in the proton density and a shift in the water condition from free water to more immobile water, which had higher sensory qualities. These effects together resulted in a reduction in thawing and cooking loss to 11.41 % and 13.83 %, respectively. These results also help to clarify the gelation process of shrimp surimi and help to regulate the gelation characteristics of shrimp surimi products.

Effect of sodium alginate ice glazing on the quality of the freeze-thawed fish balls

The effect of 1.0 % (w/v) sodium alginate (SA) glazing on surface frost formation and the quality of frozen fish balls in repeated freeze-thaw (F-T) cycles was studied. The optimal glazing property of 1.0 % SA solution was manifested by high transmittance, excellent water resistance, and high ice glazing rate. After seven F-T cycles, compared with the control, the ice production, thawing loss, and total volatile base nitrogen (TVB-N) value of samples with 1.0 % ice glazing decreased by 28.30 %, 21.02 %, and 27.35 %, while the chewiness and whiteness were increased by 15.02 % and 10.40 %, respectively. Moreover, compared to the control, the microstructure of fish balls glazed with 1.0 % SA was smoother and more uniform, and the ice crystal diameter was smaller. Therefore, 1.0 % SA glazing effectively inhibits the formation of ice crystals, reducing water migration and loss while minimizing damage to the meat structure, thus enhancing the quality of meat products.