Cooking Loss Research Articles

Enzymatic Hydrolysis of Salmon Frame Proteins Using a Sequential Batch Operational Strategy: An Improvement in Water-Holding Capacity.

The meat industry uses phosphates to improve the water-holding capacity (WHC) of meat products, although excess phosphates can be harmful to human health. In this sense, protein hydrolysates offer an alternative with scientific evidence of improved WHCs. Salmon frames, a byproduct rich in protein, must be processed for recovery. Enzymatic technology allows these proteins to be extracted from muscle, and the sequential batch strategy significantly increases protein nitrogen extraction. This study focused on evaluating the WHC of protein hydrolysates from salmon frames obtained through double- and triple-sequential batches compared to conventional hydrolysis. Hydrolysis was carried out for 3 h at 55 °C with 13 mAU of subtilisin per gram of salmon frames. The WHC of each hydrolysate was measured as the cooking loss using concentrations that varied from 0 to 5% (w/w) in the meat matrix. Compared with those obtained through conventional hydrolysis, the hydrolysates obtained through the strategy of double- and triple-sequence batches demonstrated a 55% and 51% reduction in cooking loss, respectively, when they were applied from 1% by weight in the meat matrix. It is essential to highlight that all hydrolysates had a significantly lower cooking loss (p ≤ 0.05) than that of the positive control (sodium tripolyphosphate [STPP]) at its maximum allowable limit when applied at a concentration of 5% in the meat matrix. These results suggest that the sequential batch strategy represents a promising alternative for further improving the WHC of hydrolysates compared to conventional hydrolysis. It may serve as a viable substitute for polyphosphates.

Valorization of Dairy and Fruit/Berry Industry By-Products to Sustainable Marinades for Broilers' Wooden Breast Meat Quality Improvement.

The study aims to improve the quality of wooden breast meat (WBM) via the use of newly developed marinades based on selected strains of lactic acid bacteria (LAB) in combination with the by-products of the dairy and fruit/berry industries. Six distinct marinades were produced based on milk permeate (MP) fermented with Lacticaseibacillus casei (Lc) and Liquorilactobacillus uvarum (Lu) with the addition of apple (ApBp) and blackcurrant (BcBp) processing by-products. The microbiological and acidity parameters of the fermented marinades were evaluated. The effects of marinades on the microbiological, technical, and physicochemical properties of meat were assessed following 24 and 48 h of WBM treatment. It was established that LAB viable counts in marinades were higher than 7.00 log10 colony-forming units (CFU)/mL and, after 48 h of marination, enterobacteria and molds/yeasts in WBM were absent. Marinated (24 and 48 h) WBM showed lower dry-matter and protein content, as well as water holding capacity, and exhibited higher drip loss (by 8.76%) and cooking loss (by 12.3%) in comparison with controls. After WBM treatment, biogenic amines decreased; besides, the absence of spermidine and phenylethylamine was observed in meat marinated for 48 h with a marinade prepared with Lu. Overall, this study highlights the potential advantages of the developed sustainable marinades in enhancing the safety and quality attributes of WBM.

Apparent amylose content positively influences the quality of extruded fortified rice kernels

The present research studies the impact of apparent amylose content (AAC) on the quality of fortified rice kernels (FRK), a health food designed to combat iron deficiency anemia by fortifying with iron, folic acid, and vitamin B12. Five FRK formulations with varying AAC (0.46–23.89 %) were prepared, and AAC influence on the extruder-system parameter and physicochemical, cooking, and textural properties of FRK was investigated. The torque, die-pressure, length, redness, and cooking time increased with an increase in AAC and were in the range of 12.55–22.81 Nm, 58.31–88.96 bar, 4.58–5.09 mm, 0.35–1.15, and 6.1–11.2 min, respectively. The other parameters, such as the breadth, whiteness index, and cooking loss decreased with an increase in AAC. Except for cohesiveness, all other textural properties of cooked FRK increased with an increase in AAC. These correlations of the FRK properties with AAC were confirmed through multivariate analysis. SEM, XRD, FTIR, and rheology supported the observed AAC trends in FRK properties. SEM showed a reduction in pores and cracks with an increase in AAC. The XRD and FTIR showed an increase in crystallinity with an increase in AAC due to better gelatinization leading to rapid retrogradation. This leads to better physical, cooking, and textural properties of FRK.

Exploring the dietary strategies of phenylalanine: Improving muscle nutraceutical quality as well as muscle glycogen and protein deposition in adult grass carp (Ctenopharyngodon idella)

Muscle is the main edible part of bony fish. The purpose of this study was to investigate the influences of phenylalanine (Phe) on muscle quality, amino acid composition, fatty acid composition, glucose metabolism, and protein deposition in adult grass carp. The diets at 2.30, 4.63, 7.51, 10.97, 13.53, and 17.07 g/kg Phe levels were fed for 9 weeks. The results manifested that Phe (10.97–13.53 g/kg) increased the pH of the fillets and decreased muscle cooking loss and lactic acid content; Phe (7.51–17.07 g/kg) improved the composition of the fillets in terms of flavor (free) amino acids, bound amino acids (especially EAA), and fatty acids (especially EPA and DHA); Phe (7.51–13.53 g/kg) increased muscle glycogen content (possibly related to the AMPK signaling pathway) and muscle protein deposition (possibly related to IGF-1/4EBP1/TOR and AKT/FOXOs signaling pathways). In conclusion, a diet with appropriate Phe levels could improve fillet quality.

Chitosan Coating with Rosemary Extract Increases Shelf Life and Reduces Water Losses from Beef.

This study aimed to evaluate the influence of films based on chitosan and rosemary extract on the physicochemical, microbiological, and oxidative characteristics of beef. Refrigerated steaks of Longissimus dorsi were distributed in a factorial arrangement (4 × 4) into four treatments consisting of four edible films (control; chitosan; chitosan + 4% rosemary extract; and chitosan + 8% rosemary extract) and four days of aging (0, 2, 4, and 8 days). Incorporating 4% or 8% rosemary extract into the chitosan film improved the characteristics of the films in terms of moisture absorption and elasticity. The edible coatings with chitosan and rosemary extract and the different days of aging increased the tenderness and decreased the lipid oxidation of beef. In addition, the chitosan films containing rosemary extract increased the water-holding capacity and decreased the cooking losses of beef. The films containing 4% and 8% rosemary extract decreased the development of mesophilic and psychrotrophic bacteria and Staphylococcus ssp. in beef. We recommend incorporating 4% rosemary extract into chitosan-based coatings to preserve the quality of refrigerated beef.

Performance, digestibility and meat quality from lambs fed diets with plantago lanceolata, Italian ryegrass or sainfoin herbages.

Plantago species, which is known to adapt to different climatic conditions, drought, temperature and different soil types. The aim of this study was to compare the effects of P. lanceolata herbage on fattening performance, rumen variables, digestibility, meat quality, meat nutrients and meat textural variables in lambs with the values of Italian ryegrass and sainfoin herbages. The lambs were fed total mix ration (TMR) with concentrated feed (about 30%) plus forage (about 70%) (P. lanceolata, PLA, Italian ryegrass (Lolium multiflorum); IRY or sainfoin (Onobrychis viciifolia) herbages, SAI). Twenty-four male lambs (Akkaraman breed) were assigned to three treatments with 8 lambs in each group. Fattening performance parameters, digestibility and carcass variables were determined. Meat quality and shelf life variables (oxidation, fatty acid profile and textural variables) was detected in the loin (Musculus longissimus), shoulder (M. deltoideus) and leg (M. semitendinosus) muscle samples, which were rested for 24 h +4°C and stored at -20°C for one week, one month, three months and six months. The dry matter (DM) intake, body weight gain, feed efficiency and carcass yield values of lambs, the DM and organic matter (OM) digestions (DMD and OMD) of TMRs, and the pH value, ammonia-nitrogen and short chain fatty acid (SCFA) concentrations of rumen fluid in lambs consuming PLA were similar to those of IRY and SAI (p > 0.05). PLA increased water holding capacity (WHC) and decreased cooking loss of meat compared to feeding with those of IRY and SAI (p < 0.05). The peroxide value (PV) and malondialdehyde (MDA) concentration increased with the stocking time in the meats (p < 0.05). Therefore, PV and MDA concentrations of shoulder, leg and loin meats up to 6th months for PLA were lower than those of IRY and SAI (p < 0.05). The linoleic acid concentration of loin and shoulder meats in PLA were higher than those of IRY and SAI (p < 0.05). The average oleic acid and ∑ω6 fatty acids concentration of meat in PLA was lower than those in IRY and SAI (p < 0.05). Atherogenic index and thrombogenic index values and palmitic acid levels of meat in PLA were similar to those in IRY, but lower than those in SAI (p < 0.05). Springiness, cohesiveness, resilience, hardness and chewiness values of the textural analysis parameters in meat of PLA were lower than those of IRY and SAI. As a result, effect of P. lanceolata on the fattening performance and rumen fermentation of lambs were similar with those of Italian ryegrass (Gramineae family) and sainfoin (Leguminosae family) forages and, it had a positive effect on meat quality (water holding capacity, cooking loss) and meat shelf life criteria (MDA, PV, fatty acid profile and textural variables). For functional lamb meat production, P. lanceolata can be included in the diet of lamb fattening.

Effect of κ‐carrageenan on the physicochemical and structural characteristics of ready‐to‐eat Antarctic Krill surimi gel

SummaryThe impact of κ‐carrageenan on the physicochemical structural characteristics of ready‐to‐eat (RTE) Antarctic krill surimi gel (AKSG) was investigated. The modifications in chemical bonding, protein secondary structure, protein composition and microscopic morphology were compared in both gels with and without κ‐carrageenan. According to the findings, adding 4% (w/w) κ‐carrageenan could reduce the cooking loss of AKSG significantly (P &lt; 0.05), enhance the WHC and textural quality of AKSG and RTE AKSG and increase the amount of hydrophobic and disulfide bonds so that the secondary structure of Antarctic krill proteins could be shifted to the β‐sheet. However, there was little impact on the composition of the protein molecules according to the SDS‐PAGE. In addition, the usage of κ‐carrageenan significantly alleviated the disruption of the protein gel network caused by high‐temperature and high‐pressure treatments (P &lt; 0.05). Therefore, applying κ‐carrageenan could effectively enhance the gel quality of RTE AKSG.

Uncovering quality changes of surimi-sol based products subjected to freeze–thaw process: The potential role of oxidative modification on salt-dissolved myofibrillar protein aggregation and gelling properties

Frozen surimi quality generally correlates with oxidation, but impacts of protein oxidation on salt-dissolved myofibrillar protein (MP) sol in surimi remain unclear. Hence, physicochemical and gelling properties of MP sol with different oxidation degrees were investigated subjected to freeze–thaw cycles. Results showed that mild oxidation (≤1 mmol/L) improved unfrozen MP gel quality with lowest cooking loss (3.29 %) and highest hardness (829.76 N). Whereas, oxidized sol suffering freeze-thawing degenerated severely, showing reduction of 23.85 % of salt soluble protein contents with H2O2 concentrations of 10 mmol/L. Shearing before heating influenced gelling properties of freeze-thawed sol, depending on oxidation levels. Oxidized gel with shearing displayed disorganized network structures, whereas gel without shearing displayed relatively complete appearances without holes under high oxidation condition (10 mmol/L). Overall, freeze–thaw process aggravated denaturation extents of MP sol subjected to oxidation, further causing high water loss and yellow color of heat-induced gel, especially to gel with shearing.

Declined flesh quality resulting from niacin deficiency is associated with elevated glycolysis and impaired mitochondrial homeostasis in grass carp (Ctenopharyngodon idella)

Energy metabolism exerts profound impacts on flesh quality. Niacin can be transformed into nicotinamide adenine dinucleotide (NAD), which is indispensable to energy metabolism. To investigate whether niacin deficiency could affect energy metabolism and flesh quality, six diets with graded levels of 0.49, 9.30, 21.30, 33.30, 45.30 and 57.30 mg/kg niacin were fed to grass carp (Ctenopharyngodon idella) for 63 days. The results showed that niacin deficiency declined flesh quality by changing amino acid and fatty acid profiles, decreasing shear force, increasing cooking loss and accelerating pH decline. The accelerated pH decline might be associated with enhanced glycolysis as evident by increased hexokinase (HK), pyruvate kinase (PK) and lactic dehydrogenase (LDH) activities, and mitochondrial dysfunction as evident by destroyed mitochondrial morphology, impaired respiratory chain complex I and antioxidant ability. Based on PWG and cooking loss, the niacin requirements for sub-adult grass carp were 31.95 mg/kg and 29.66 mg/kg diet, respectively.

The Effects of Four Different Thawing Methods on Quality Indicators of Amphioctopus neglectus.

Amphioctopus neglectus is a species of octopus that is favored by consumers due to its rich nutrient profile. To investigate the influence of different thawing methods on the quality of octopus meat, we employed four distinct thawing methods: air thawing (AT), hydrostatic thawing (HT), flowing water thawing (FWT), and microwave thawing (MT). We then explored the differences in texture, color, water retention, pH, total volatile basic nitrogen (TVB-N), total sulfhydryl content, Ca2+-ATPase activity, and myofibrillar protein, among other quality indicators in response to these methods, and used a low-field nuclear magnetic resonance analyzer to assess the water migration that occurred during the thawing process. The results revealed that AT had the longest thawing time, leading to oxidation-induced protein denaturation, myofibrillar protein damage, and a significant decrease in water retention. Additionally, when this method was utilized, the content of TVB-N was significantly higher than in the other three groups. HT, to a certain extent, isolated the oxygen in the meat and thus alleviated protein oxidation, allowing higher levels of Ca2+-ATPase activity, sulfhydryl content, and springiness to be maintained. However, HT had a longer duration: 2.95 times that of FWT, resulting in a 9.84% higher cooking loss and a 28.21% higher TVB-N content compared to FWT. MT had the shortest thawing time, yielding the lowest content of TVB-N. However, uneven heating and in some cases overcooking occurred, severely damaging the protein structure, with a concurrent increase in thawing loss, W value, hardness, and shear force. Meanwhile, FWT improved the L*, W* and b* values of octopus meat, enhancing its color and water retention. The myofibrillar protein (MP) concentration was also the highest after FWT, with clearer subunit bands in SDS-PAGE electrophoresis, indicating that less degradation occurred and allowing greater springiness, increased Ca2+-ATPase activity, and a higher sulfhydryl content to be maintained. This suggests that FWT has an inhibitory effect on oxidation, alleviating protein oxidation degradation and preserving the quality of the meat. In conclusion, FWT outperformed the other three thawing methods, effectively minimizing adverse changes during thawing and successfully maintaining the quality of octopus meat.

Effects of Low Temperature-Ultrasound-Papain (LTUP) Combined Treatments on Purine Removal from Pork Loin and Its Influence on Meat Quality and Nutritional Value.

A combined pretreatment method of "low temperature-ultrasound-papain" (LTUP) was proposed to remove the purine of pork loins. Compared with untreated pork loin, under optimal conditions (temperature 58 °C, ultrasound density 100 W/cm2, and papain concentration 0.085%), the purine removal rate of treated pork loin could reach 59.29 ± 1.39%. The meat quality of pork loin treated with the LTUP method such as hardness and chewiness decreased by 58.37% and 64.38%, respectively, and the in vitro protein digestibility was increased by 19.64%; the cooking loss was decreased by 15.45%, compared with the simulated household blanching process (HT). In view of the high purine removal rate, the losses of free amino acids and soluble peptides were acceptable and reasonable. SEM and LF-NMR results showed that low temperature and ultrasound combined with papain treatment opened a channel for purine transfer and promoted purine dissolution by affecting the protein structure of pork loin. In addition, the migration of water within the muscle tissue was also related to purine removal. In summary, LTUP is recommended as an efficient and green way for the meat industry to remove purine.

Effect of Static Magnetic Field on the Quality of Pork during Super-Chilling Storage.

Fresh pork tenderloin was stored at -3 °C under different static magnetic fields (SMF) of 0, 4, and 10 mT (control, MF-4, and MF-10) to investigate their physicochemical properties changes during storage of 8 days. The initial equilibrium temperature of the samples stored with 4 mT MF was found to be -2.3 °C, which was slightly lower (0.3 °C) than that the control value. The super-chilling phenomenon on the pork was then observed, as the samples stored under the magnetic field did not freeze throughout storage period, but the control experienced a sudden change in temperature after 138 h and then froze. The preservation effect of MF-4 on meat quality was the best in all treatment groups. MF-4 achieved a higher water-retention rate, with drip and cook losses of 6.5% and 29.0% lower than the control, respectively. Meanwhile, the MF-4 effectively delayed the color change in the meat during the storage and the texture hardening after cooking, and effectively controlled the growth of the total volatile saline nitrogen content on the samples. In addition, MF-4 delayed the reduction in myofibrillar protein solubility, sulfhydryl content, and emulsification capacity, indicating that this field inhibited the denaturation of myofibrillar protein. This study can be considered as an application reference of magnetic fields during meat storage at a super-chilled temperature.

Assessing meat quality and textural properties of broiler chickens: the impact of voltage and frequency in reversible electrical water-bath stunning

The implementation of the head-only electrical stunning procedure in poultry processing has been aimed at enhancing eating, ethical, and religious quality. However, inconsistencies in voltage and frequency standardization, along with variations in previous research outcomes, have led to numerous cases of both under-stunned and over-stunned birds. Thus, this study aimed to comprehensively evaluate the effects of varying voltages and frequencies during electrical water bath stunning on carcass quality, meat attributes, and textural properties in broiler chickens. A cohort of 240 healthy female broilers (Cobb 500, 42-days-old, 2 kg ± 0.1 kg) was meticulously selected from a commercial farm. The birds underwent exposure to different stunning voltages (2.5, 10.5, 30, and 40 V) and frequencies (50 and 300 Hz). Subsequent analyses were conducted on meat samples to assess physicochemical properties, carcass quality, and textural attributes. The findings revealed a higher incidence of petechial hemorrhage (P < 0.05) in birds stunned at 10.5 V compared to other voltage. Notably, no broken bones were recorded in birds subjected to high voltages (30 and 40 V). Low frequency (50 Hz) significantly increased the occurrence of petechial hemorrhage and simultaneously resulted in pectoralis major muscle with decreased redness (a*). Birds subjected to the 10.5 V stunning treatment exhibited a lower cooking loss percentage. Significant interactions between voltage and ageing (V × A) were observed. Birds stunned at 30 V and aged for 7 d displayed highest drip loss compared to a one-day ageing period across different voltage levels. This interaction also impacted pH values, with birds subjected to 10.5 V showing significantly lower (P < 0.05) pH at d 7 of ageing. The meat hardness was influenced by the V × A interaction, wherein birds stunned at 10.5 V exhibited lower hardness after one day of ageing compared to other voltage levels. Red wing tips, lightness (L*), adhesiveness, and resilience were also significantly impacted (P < 0.05) by the interaction between frequency and voltage. A notable 3-way interaction was observed for gumminess and chewiness (F × V × A), where the 2-way interaction between frequency and voltage (F × V) affected both parameters differently at various ageing periods. Additionally, there was a significant interaction (P < 0.05) between frequency and voltage influencing shear strength and yellowness.

Effect of bran backfilling on the quality and nutritional properties of extruded Tartary buckwheat noodles

In this study, the effect of bran backfilling to Tartary buckwheat (at 0, 6, 12, 18, 24, or 30%) with respect to flour properties, cooking and nutritional characteristics of extruded noodles was investigated. The optimum cooking time and cooking loss of the Tartary buckwheat-extruded noodles increased when bran was added, but the hardness, springiness, and chewiness decreased. The phenolic increased in Tartary buckwheat flour in line with the amount of bran added, with further increases being observed after extrusion. As the amount of bran added increased, the soluble dietary fiber also increased, rising to between 2.14 and 4.34% after extrusion. Simultaneously, the predicted glycemic index decreased from 54.74 to 48.04. Our results demonstrate that though addition of bran may reduce the cooking quality of the noodles, but nutrition value significantly increased. This finding provides an important basis for future research into the development of Tartary buckwheat noodles for improved nutritional content.

Microbiota differences of giant river prawn (Macrobrachium rosenbergii) cultured in a recirculating aquaculture system (RAS) – A prototype vertical farming and traditional pond cultured system and their impact on autolysis rate and textural characteristics

Microbial profiles, autolysis rates, and textural characteristics of giant river prawn (Macrobrachium rosenbergii) cultured in a vertical farming with a recirculating aquaculture system (RAS) were compared to those of prawns cultured in a traditional pond system (Pond). Bioinformatics analysis revealed significant differences in the quantity and diversity of microbial communities between RAS and Pond. Firmicutes were the dominant phylum found in both samples but at higher levels in Pond (P < 0.05). Conversely, Tenericutes, Proteobacteria, and Actinobacteria, known as healthy microbiomes, were more abundant in RAS (P < 0.05). At the genus level, Enterococcus, recognized for its potential to improve colonization resistance against pathogens in the gut, was detected at higher levels in RAS (P < 0.005). This variation in microbiota might affect the difference in autolysis rates and textural properties between these two samples. RAS had a lower autolysis rate at all temperatures (4, 15, 25, and 35 °C) (P ˂ 0.05), consistent with the lower TCA-soluble peptide (157.61 μmol tyrosine equivalent/g sample). The differences in textural characteristics of these two prawns were observed. RAS had more water holding capacity (WHC) (80.07%) but lower drip loss (15.75%) and cooking loss (28.36%) than Pond (73.77, 17.84, and 31.20%, respectively) (P ˂ 0.05). From TPA results, RAS showed higher chewiness and gumminess than Pond, indicating a firmer texture, which is a desirable characteristic, particularly in fresh prawn. Overall, the findings indicated an improvement in microbial profiles, which further translated into economic benefits in terms of yield production and muscle quality, particularly texture, of prawn cultured in a recirculating aquaculture system as an alternative approach.

Microwave- and Oven-Heat Moisture Treatment of Broken Rice Flour and the Improvement in Flat Rice Noodle Quality

The characteristics of starch used in the production of rice noodles greatly influenced the product quality. Some rice noodle varieties are made from rice flour, which is typically derived from broken rice grains. Broken rice flour has been associated with a higher level of starch damage that could adversely affect the cooking, textural, and eating qualities of noodles. Hydrothermal treatments have been proposed as a technique for improving starch functionality. This study aims to investigate the effect of different techniques employed in heat moisture treatment (HMT) applied to broken rice (MR263) and their impact on flat rice noodle quality. Rice flour adjusted to 20% moisture content was subjected to two HMT techniques; oven-heat moisture treatment (O-HMT) at 110°C for 3 h and microwave-heat moisture treatment (M-HMT) at 119 W for 5 min. HMT reduced the swelling capacity and solubility of the flour. M-HMT flour had the lowest swelling capacity, whereas O-HMT flour exhibited the lowest solubility. The oven-HMT reduced the L* and whiteness index values of both rice flour and noodles, whereas the microwave-HMT recorded comparable color parameters as the non-treated samples. HMT improved the cooking quality of flat rice noodles, resulting in lower water absorption and cooking loss. Noodles made with oven-treated flour had the lowest cooking loss, whereas the microwave-treated flour resulted in noodles with the lowest water absorption. O-HMT produces noodles with greater improvement in gel texture. Despite the reduced whiteness of the O-HMT noodle, it received higher consumer acceptance in terms of appearance, color, flavor, and hardness. Heat moisture treatment can be used as an economical viable technique for enhancing the quality of flat rice noodles. The varying noodle quality resulting from both oven- and microwave-HMT is attributed to a distinct degree of molecular changes in the starch components, which eventually impact the overall product quality.

Inhibition of the interactions of myofibrillar proteins with gallic acid by β-cyclodextrin-metal-organic frameworks improves gel quality under oxidative stress

Generally, high levels of natural phenolic antioxidants, which are needed in meat products to exert equivalent antioxidant effects as synthetic antioxidants, can interact with myofibrillar proteins and cause aggregation of the proteins, giving rise to undesirable deterioration of gel quality. In this study, β-cyclodextrin-metal-organic frameworks (K-β-CD-MOFs) were synthesized based on β-CD and K+ ions using methanol vapor diffusion method, and used to inhibit excessive covalent and non-covalent interactions between gallic acid (GA) and myofibrillar proteins under oxidative stress without degrading the phenolic antioxidant activity. Results of zeta potential, scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC) provided evidence for the formation of GA/K-β-CD-MOFs inclusion complexes. From sulfydryl content, surface hydrophobicity, tryptophan fluorescence, turbidity and particle size analyses, the presence of K-β-CD-MOFs dose-dependently prevented the sulfydryl loss, unfolding of the proteins and formation of insoluble aggregates caused by GA (180 μM/g protein). Dynamic rheology, cooking loss, gel strength, water distribution, microstructure and Raman spectrum were further tested to evaluate effects of K-β-CD-MOFs on the qualities of GA-treated myofibrillar protein gel. Results indicated that more proteins were involved in the formation of a more ordered and homogeneous gel structure with higher gel elasticity and strength, more immobilized water and decreased cooking loss. The overall gel properties of myofibrillar proteins were improved. K-β-CD-MOFs ameliorated the instability of protein structure, manifested as increase in β-sheet content and inter-chain hydrogen bonding and decrease in hydrophobic forces (p < 0.05). This paper provides a novel method to increase the loading amount of phenolic antioxidants without jeopardizing the gel quality of meat products.

Effect of ultrasonic processing on beef tenderness in longissimus lumborum during aging by proteomics analysis

This investigation was aimed to evaluate the proteins related to beef tenderness at different aging times (1, 3, 7 d) and to explain the changes in the longissimus lumborum at the molecular level with ultrasound treatment. The pH value decreased significantly (p<0.05) with increasing aging time, and was lower in the ultrasonic group compared to the non-ultrasonic group. It indicated that ultrasound had a positive effect on tenderness by maintaining lower cooking loss, higher water-holding capacity (WHC), and higher myofibril fragmentation index (MFI), as demonstrated by the immunoblotting analysis of desmin and caspase-3. Twenty-eight proteins were identified as potential markers of tenderness. A PCA analysis confirmed the differential expression of tenderness-related proteins. Bioinformatics analysis suggested that these proteins, which were distributed in the cytoplasm, membrane, and mitochondria, were more likely to be impacted by ultrasound. Overall, the identified proteomics database of beef serves as a valuable reference for using ultrasound to enhance meat quality and reduce aging duration.

Effect of plant polysaccharides on the conformation and gel properties of the Eugenol–Myofibrillar protein complex

This study investigated the effect of plant polysaccharides on the conformation and gel properties of the eugenol (Eu)-myofibrillar protein (MP) complex. Adding 0.5% inulin (I) and konjac glucomannan (K), which are two plant polysaccharides, to the Eu-MP complex lead to the inhibition of the Eu–MP interaction, which significantly increased carbonyl and thiol contents and surface hydrophobicity. Both polysaccharides significantly inhibited the reduction in the α-helix content (Eu-MP: 14.95%; Eu-MP-I: 18.04%; Eu-MP-K: 19.92%), thereby maintaining hydrogen bond stability in the protein. I and K significantly increased the strength of the complex gel and the storage modulus. Additionally, I and K promoted the formation of a denser gel structure of the Eu-MP complex, which significantly decreased moisture migration and the cooking loss of the gel. This study thus provides a theoretical basis for adding polysaccharide to inhibit the polyphenol–protein interaction so as to enhance the functional properties of proteins, as well as the practical application of polyphenols and polysaccharides in meat product processing.

Maceration Frequency Impacts Semitendinosus and Biceps femoris Surface Area, Cooking Loss, and Palatability Outcomes

We examined the effect of maceration frequency on surface area, purge loss, and palatability of eye of round and bottom round steaks. Beef eye of round (n = 12) was cut into 8 steaks each and randomly assigned to 0, 1, 2, or 3 macerations and uncooked or cooked slice shear force (SSF) tenderness determinations. Bottom round muscles (n = 12) were cut into 12 steaks and randomly assigned to 0, 1, 2, or 3 macerations and uncooked or cooked SSF or trained sensory evaluations. Steaks were trimmed to a common size (50 cm2 for eye of round and 80 cm2 for bottom round) prior to maceration with a commercial steak tenderizer. Data were analyzed via mixed ANOVA models using a randomized complete block design. Surface area increased (P &amp;lt; 0.001) by 15.4%, 38.6%, and 62.4% for eye of round steaks and 22.0%, 51.3%, and 70.3% for bottom round steaks after 1, 2, or 3 macerations, respectively. Purge losses did not differ (P &amp;ge; 0.247) for either muscle due to maceration frequency. Uncooked SSF values for eye of round steaks were decreased (P &amp;lt; 0.001) by 6.6%, 19.5%, and 40.0% after 1, 2, and 3 macerations; however, cooked SSF values did not differ (P = 0.077). For bottom round steaks, uncooked SSF values were decreased (P &amp;lt; 0.001) by 32.0%, 45.5%, and 67.2% after 1, 2, and 3 macerations; cooked SSF values for steaks macerated 3 times were 26.6% lower (P = 0.022) than steaks macerated 0, 1, or 2 times. Cooking losses were greater (P &amp;lt; 0.001) for macerated eye of round (5.4% to 7.2%) and bottom round steaks (7.6% to 10.8%). Maceration decreased (P &amp;lt; 0.001) sensory juiciness and connective tissue ratings and increased (P &amp;lt; 0.001) sensory tenderness ratings. Maceration increased surface area and improved tenderness.