Volatile Compounds for Discrimination between Beef, Pork, and Their Admixture Using Solid-Phase-Microextraction-Gas Chromatography-Mass Spectrometry (SPME-GC-MS) and Chemometrics Analysis.

This study addresses the prevalent issue of meat species authentication and adulteration through a chemometrics-based approach, crucial for upholding public health and ensuring a fair marketplace. Volatile compounds were extracted and analyzed using headspace-solid-phase-microextraction-gas chromatography-mass spectrometry. Adulterated meat samples were effectively identified through principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA). Through variable importance in projection scores and a Random Forest test, 11 key compounds, including nonanal, octanal, hexadecanal, benzaldehyde, 1-octanol, hexanoic acid, heptanoic acid, octanoic acid, and 2-acetylpyrrole for beef, and hexanal and 1-octen-3-ol for pork, were robustly identified as biomarkers. These compounds exhibited a discernible trend in adulterated samples based on adulteration ratios, evident in a heatmap. Notably, lipid degradation compounds strongly influenced meat discrimination. PCA and PLS-DA yielded significant sample separation, with the first two components capturing 80% and 72.1% of total variance, respectively. This technique could be a reliable method for detecting meat adulteration in cooked meat.

Comparison of Chemical Composition, Quality, and Muscle Fiber Characteristics between Cull Sows and Commercial Pigs: The Relationship between Pork Quality Based on Muscle Fiber Characteristics.

This study aims to compare the chemical composition, quality, and muscle fiber characteristics of cull sows and commercial pigs, investigating the effect of changes in muscle fiber characteristics on pork quality. The proximate composition, color, pH, water-holding capacity (drip loss and cooking loss), protein solubility, total collagen content, and muscle fiber characteristics of cull sows (n=20) and commercial pigs (n=20) pork were compared. No significant differences were found between cull sows and commercial pigs in terms of proximate composition, drip loss, protein solubility, or total collagen content of their meat (p<0.05). However, cull sow pork exhibited a red color and a higher pH (p<0.05). This appears to be the result of changes in muscle fiber number and area composition (p<0.05). Cull sow meat also displayed better water-holding capacity as evident in a smaller cooking loss (p<0.05), which may be related to an increase in muscle fiber cross-sectional area (p<0.05). In conclusion, muscle fiber composition influences the pork quality; cull sow pork retains more moisture when cooked, resulting in minimal physical loss during processing and can offer more processing suitability.

Comparing Physicochemical Properties, Fatty Acid Profiles, Amino Acid Composition, and Volatile Compounds in Dry-Cured Loin: The Impact of Different Levels of Proteolysis and Lipid Oxidation.

The aim of this study is to compare the quality characteristics of dry-cured loins with different levels of proteolysis and lipid oxidation and to investigate the relationship between these factors on quality characteristics. The dry-cured loins were divided into four groups [proteolytic index (PI) and 2-thiobarbituric acid reactive substances (TBARS) of high levels (HH), PI of high level and TBARS of low level (HL), PI of low level and TBARS of high level (LH), and PI and TBARS of low levels (LL)] based on the proteolysis index and TBARS. Moisture, protein, and fat content were all significantly influenced by proteolysis and lipid oxidation (p<0.05). The total fatty acid content in the high proteolysis groups (HH and HL) was significantly lower than that in the low proteolysis groups (LH and LL; p<0.05). For total free amino acid content, HH was the highest, and LL was the lowest (p<0.05). On the other hand, there was no significant difference between HL and LH (p>0.05). In the amount of total volatile compounds, there was no significant difference between HH and HL (p>0.05), but LH and LL significantly differed (p<0.05). In conclusion, proteolysis and lipid oxidation can influence the quality characteristics of dry-cured loin. Additionally, proteolysis might be as influential in generating volatile compounds as lipid oxidation.

Paprika extract as a natural antioxidant in cold-stored pork patties: Effect on oxidative stability and heterocyclic amines inhibition.

In this study, we compared the degree of oxidation of pork patties refrigerated at 7 °C for 0, 7, and 14 days and the content of 10 types of heterocyclic amines (HCAs) after heating. The pork patties used in the study were added with 0.7 mg sodium nitrite (SN) and 5 mg paprika extract (PE), respectively. IQx (2-Amino-3-methyl-imidazo[4,5-f]-quinoxaline), MeIQx (2-Amino-3, 8-dimethyl-imidazo[4,5-f]-quinoxaline), PhIP (2-Amino-1-methyl-6-phenyl-imidazo[4,5-b]-pyridine), and Harman (1-Methyl-9H-pyrido[4,3-b]-indole) contents increased with increasing storage periods of treatment. On the other hand, HCAs production in SN and PE treatments were suppressed over the storage period, with IQ (2-Amino-3-methyl-imidazo[4,5-f]-quinoline) and Aαc (2-Amino-9H-dipyrido[2,3-b]-indole) being suppressed significantly (P < 0.05). The control's pH, cooking loss, lipid, and protein oxidation were higher than SN and PE-treated patties at 14 d (P < 0.05). These differences affect the formation of HCAs. PLS-DA showed a strong correlation between protein oxidation and IQx, Harman, 4,8-DiMelQx (2-Amino-3, 4, 8-trimethyl-imidazo[4,5-f]-quinoxaline), PhIP, and MeIQx, while lipid oxidation correlated with IQx, Harman, and PhIP. Both SN and PE showed HCAs inhibitory activity and exhibited oxidative stability during storage.

Comparison between Berkshire and crossbreed on meat quality, and investigation of the relationship with fatty acid composition and meat quality.

This study aimed to compare meat quality traits between Berkshire and crossbreed (Landrace × Yorkshire × Duroc), and to investigate the relationship between meat quality traits and fatty acid composition. 20 Berkshire and 20 crossbreed pigs were used to compare pork loin quality and to determine the relationship between measured variables. 23 variables were measured including proximate composition, pH, drip loss and cooking loss, Warner-Bratzler shear force, and fatty acid composition. Berkshire had higher moisture content, pH, water-holding capacity, saturated fatty acids, and redness than the crossbreed pig (p < 0.05). The fat content and polyunsaturated fatty acid were low (p < 0.05) in Berkshire. Correlation analysis showed a negatively correlation between moisture and fat content, and a positively correlation between saturated fatty acid and fat content. Moreover, saturated fatty acid and polyunsaturated fatty acid were negatively correlated. As a result of factor analysis and partial least square regression, saturated fatty acid and polyunsaturated fatty acid were estimated to be the main factors affecting quality characteristics of pork. Pig breed is associated with differences in meat quality, and fatty acid composition can have an effect on meat quality parameters.

Inhibitory and antioxidative capacity of nutmeg extracts on reduction of lipid oxidation and heterocyclic amines in pan-roasted beef patties.

Identification and inhibition of mutagenic and carcinogenic heterocyclic amines (HCAs) from pan-roasted beef patties were performed by adding (0.02%) tertiary butyl hydroquinone (TBHQ) and (0.05%) ethanol-extracted nutmeg (ENE) using HPLC and principal component analysis. Ten HCAs, including six polar and four non-polar, were assessed. The addition of (0.05%) ENE significantly (P < 0.05) reduced the cooking loss and shrinkage of patties during cooking and reduced the total formation HCAs by 73.97%, which proved the significant (P < 0.05) inhibitory effect as a natural antioxidant against lipid oxidation and HCA formation compared to TBHQ. The DPPH radical-scavenging activity, total phenolic content, and available active metabolites of ENE were estimated. Furthermore, a positive correlation was observed between pH, level of thiobarbituric acid reactive substances, and HCA formation in both the groups. TBHQ and ENE were significant HCAs inhibitors (P < 0.001), but ENE showed resilient oxidative stability during refrigeration storage. Therefore, ENE can be used to reduce HCAs formation in pan-roasted beef patties.

Changes in Quality Traits and Oxidation Stability of Syzygium aromaticum Extract-Added Cooked Ground Beef during Frozen Storage.

This study was accomplished by comparing the oxidative stability of (0.1%) Syzygium aromaticum extract (SAE) and (0.02%) butylated hydroxytoluene (BHT)-added cooked ground beef with an antioxidant free-control sample during frozen storage. All samples showed a non-significant (p > 0.05) effect on pH, thawing loss, redness, and yellowness values during storage. Incorporation of BHT and SAE led to a significant (p < 0.05) reduction in thiobarbituric acid-reactive substances (TBARS) and volatile levels as an active antioxidant. The generation of less volatiles found in SAE-treated samples up to 6 months (p < 0.05) of storage. Therefore, SAE-protected ground beef can lead to lower lightness, lipid oxidation, and volatile compounds levels after cooking compared with control and BHT samples.

Effect of Pig Breed and Processing Stage on the Physicochemical Properties of Dry-Cured Loin.

This study investigated the effect of pig breeds on the quality characteristics of dry-cured loins according to the processing stage. Physicochemical properties of 20 dry-cured processed loins with the different pig breeds [Berkshire vs Landrace×Yorkshire× Duroc (LYD; n=10)] and different processing stages (raw, curing, dry-ripened 15 day and 30 day) were analyzed. The pig breed influenced moisture content and pH with values of 59% and 53%, and 6.17 and 5.94, for Berkshire and LYD, respectively, on day 30. Dry-cured loins made with Berkshire showed higher hardness and lower cohesiveness than that of the LYD (p<0.05). Redness and yellowness were higher for Berkshire than LYD (p<0.05). Lipid oxidation and lightness did not affect by pig breed during processing stages (p>0.05). However, sulfhydryl content was significantly higher in Berkshire compared to the LYD after dry-ripened for 15 days (p<0.05). The concentration of total free amino acids and fatty acids was higher for Berkshire during all processing stages (p<0.05). Berkshire may be better quality due to its high moisture content and pH compared to the LYD.

Utilization of Astaxanthin as a Synthetic Antioxidant Replacement for Emulsified Sausages.

The aim of this study was to evaluate the effect of astaxanthin (AX) on the quality and sensory characteristics of emulsified pork sausages during cold storage. The changes of Peroxide value (PV), 2-thiobarbituric acid-reactive substances (TBARS), thiol content, texture profile analysis, instrumental color, and sensorial qualities were assessed on specific storage days. The emulsified sausages with added AX exhibited significantly (p < 0.05) higher redness values and total color differences (ΔE) on all storage days. Sensory values recorded the reddest color and greater overall acceptability scores to the sample with AX. In addition, AX had a significantly (p < 0.05) greater effect on PV, TBARS, and thiol content of sausages, compared with the control (CON). AX showed higher oxidation stability than CON for regression coefficient, and the level of inhibition of malondialdehyde formation was similar to that of butylated hydroxytoluene (BHT) on storage days. Synthetically, AX had a desirable consequence on antioxidant activity and color of emulsified sausages; therefore, it can be used as a multifunctional additive in emulsified pork sausages.

Arginine supplementation may improve color and redox stability of beef loins through delayed onset of mitochondrial-mediated apoptotic processes.

The objective of this study was to evaluate the effects of arginine (ARG) and/or lysine (LYS) supplementation on meat quality and oxidative stability of beef loins. Steers (n = 40) were split among four dietary treatments (control, ARG, LYS or ARGLYS). The loins (longissimus lumborum) were obtained at 1 day postmortem and aged either 14 or 28 days prior to cutting of steaks for 7 days of display. No impacts of diet treatments on instrumental tenderness, water-holding capacity and fatty acid profiles were found (P > 0.05). Extended aging significantly decreased lipid oxidative stability, color stability and reducing ability of loins. However, steaks from ARG and ARGLYS maintained superior color stability coupled with lower mitochondrial membrane permeability and higher cytochrome c redox stability compared to control (P < 0.05). These results indicate that ARG supplementation can improve color stability of beef loins possibly through delayed onset of mitochondrial-mediated apoptotic processes.

Assessment of the Stability of Fresh Beef Patties with the Addition of Clove Extract during Frozen Storage.

The study assessed the stability for fresh beef patties with the inclusion of clove extract (CE) as a natural antioxidant in comparison to butylated hydroxytoluene (BHT) and ascorbic acid (AA) at frozen storage. Four different patties were made dependent on the added antioxidants: control (added no antioxidants), added with 0.02% BHT, 0.05% AA, and 0.1% CE. Inclusion of BHT, AA, and CE resulted in a significant reduction of thiobarbituric acid reactive substances (TBARS) and hue angle (h°) value and increase of redness (CIE a*) and chroma (C*) values (p<0.05). BHT, AA, and CE were observed effectively to retard lipid oxidation and increase color stability. BHT and AA revealed significantly (p<0.05) higher thiol content than the control and CE. However, the reduction percentage for thiol content in CE treated patties was lower than the control and AA-treated patties from first to last time of storage. Moreover, inclusion of AA and CE led to significantly (p<0.05) increased heme iron content when compared to BHT and the control. In conclusion, CE can replace the application of AA and BHT while improving lipid stability, heme iron content, and color stableness of fresh beef patties throughout frozen storage.

Combined impacts of initial freezing rate of pork leg muscles (M. biceps femoris and M. semitendinosus) and subsequent freezing on quality characteristics of pork patties.

The objective of this study was to determine the combined impacts of initial sub-primal freezing with subsequent freezing of manufactured pork patties on quality attributes and oxidative stability. Patties were manufactured (n = 3 batches) from pork leg muscles (M. biceps femoris and M. semitendinosus) frozen at different methods including still-air freezing (SAF), blast freezing (BF), and cryogenic freezing (CF). Then, patties were subjected to additional freezing treatments. Frozen/thawed patties exhibited increased cooking loss, springiness, and chewiness, lipid and protein oxidation, and decreased protein solubility compared to unfrozen counterparts (P < .05). However, patties from CF legs maintained similar protein solubility and lipid/protein oxidation compared to unfrozen controls (P > .05), while significantly minimizing sub-primal thawing loss and oxidation compared to patties from SAF. The results of the present study suggest the importance of initial freezing rate of sub-primals with subsequent freezing on quality characteristics of frozen/thawed meat patties.

Influence of Reheating Methods and Frozen Storage on Physicochemical Characteristics and Warmed-Over Flavor of Nutmeg Extract-Enriched Precooked Beef Meatballs.

The effects of convection-oven precooking, frozen storage (-18 °C/ two months) and four different reheating methods-namely, boiling, pan-roasting, convection oven and microwave oven on pH, color, texture, antioxidant activity and warmed-over flavor of beef meatballs were investigated. In this study, four kinds of beef meatballs were prepared: with added butylated hydroxyl toluene (0.02% BHT, M1); with nutmeg extract (0.02%, M2); with nutmeg powder (0.02%, M3) and control (no antioxidant). Addition of (0.02%) nutmeg extracts in beef meatballs M2 resulted in a significant (p < 0.05) decrease in lipid and protein oxidation, hardness and gumminess values after convection oven precooking. Again, M2 reheated by microwave oven significantly (p < 0.05) reduced cooking loss, gumminess, springiness, rancid flavor, saltiness and burnt taste and increased oxidative stability, redness and adhesiveness with the chewiness intensity and overall acceptability compared to control, M1 and M3. Conclusively, the addition of nutmeg extracts (0.02%) as a natural plant antioxidant to precooked beef meatballs can result in reduced lipid and protein oxidation levels, stabilized color and texture values and improved overall acceptance after reheated by microwave oven during two months of frozen storage.

Effects of clove extract on oxidative stability and sensory attributes in cooked beef patties at refrigerated storage.

The antioxidant effects of clove extract (CE) by comparing with BHT and ascorbic acid (AA) in cooked beef patties were assessed at refrigerated storage. Four kinds of patties were formulated: without antioxidants (control), with added 0.02% BHT, 0.05% AA, and 0.1% CE. Addition of BHT, AA, and CE resulted in a significant (p < .05) decrease in thiobarbituric acid reactive substance (TBARS) value, carbonyl content, and hue angle; increasing of redness value; and improvement of the stability of sensory attributes. Addition of CE showed reduced protein and lipid oxidation when compared with BHT (p < .05). Moreover, CE presented lower lipid oxidation, and a higher redness value and overall color score than the AA (p < .05). Sensory assessment regarding overall color, discoloration, and odor showed that CE inclusion in patties extended the storage life up to 10 days. Therefore, the application of CE as a natural antioxidant can result in reduced protein and lipid oxidation and enhance the quality of cooked beef patties.

Effects on quality properties of cooked pork sausages with Caesalpinia sappan L. extract during cold storage.

This study was evaluated the possibility of replacing some chemical additives in meat products by the Caesalpinia sappan L. (CS) extract. Four different types of cooked pork sausages were prepared by mixing nitrite with CS extracts at different concentration like control (without nitrite and extract), T1 (0.007% nitrite), T2 (0.004% nitrite + 0.05% extract) and T3 (0.1% extract). Physicochemical properties, sensory attributes, and antioxidant activity of the control and treatments were investigated. Ash contents and DPPH radical scavenging activity were significantly (P < 0.05) higher when pork sausages were processed with the addition of CS extracts. The rate of lipid oxidation significantly (P < 0.05) decreased in the case of CS extracts addition. By comparing with the control, all nitrite or CS extract resulted in significant (P < 0.05) lower L* values; however, 0.007% nitrite and 0.004% nitrite plus 0.05% CS extract pointed significantly (P < 0.05) higher a* values in all storage times. As well as, arrangement of CS extracts (0.05%) and nitrite (0.004%) in pork sausages displayed high gumminess and cohesiveness values (P < 0.05), stable springiness and chewiness, and significantly (P < 0.05) enhance overall acceptability scores as sensory attributes compared to the control sausage after 30 days of storage. Therefore, the CS extract (0.05%), which can act as a natural antioxidant, exert a positive effect with nitrite (0.004%) on the sensory acceptability and help to preserve the desired color of cooked pork sausages by reducing oxidation rate during cold storage.

Comparison of Butylated Hydroxytoluene, Ascorbic Acid, and Clove Extract as Antioxidants in Fresh Beef Patties at Refrigerated Storage.

This study was performed to assess the comparison of the effects amongst butylated hydroxytoluene (BHT), clove extract (CE), and ascorbic acid (AA) as antioxidants on the oxidative stability and color values in fresh beef patties. The adding of BHT, AA, and CE to patties significantly restrained lipid oxidation, lowered hue angle as color value, and expanded redness and chroma values of fresh beef patties in comparison to the control (p<0.05). BHT and AA significantly led to impede the protein oxidation of patties by lowering carbonyl content (p<0.05). CE had no negative effect on protein oxidation. The antioxidant effects of BHT, AA, and CE were obviously manifested. Nonetheless, BHT, AA, and CE appeared to have insignificant difference of each other for lowering the protein oxidation at the end of storage. BHT and CE represented lowered lipid oxidation in comparison to AA. The antioxidant effects of BHT, AA, and CE on lipid oxidation were more marked than the effects on protein oxidation. Furthermore, CE as a natural antioxidant evinced the efficiency in oxidative stability and color stability in fresh beef patties. The study implied that CE could substitute the use of BHT and AA when making beef patties during storage.

Physicochemical properties, sensory traits and storage stability of reduced-fat frankfurters formulated by replacing beef tallow with defatted bovine heart.

The consumer interests for low-fat meat products are increasing to reduce obesity and chronic diseases. Reduced-fat frankfurter (RFF) was prepared by replacing beef tallow with defatted bovine heart (DBH) produced by supercritical-CO2 (SC-CO2) and hexane. Six different frankfurters i.e. control (20% beef fat), T1 (30% fat replacement with non-defatted bovine heart), T2 and T3 (20% and 30%, respectively, fat replacement with SC-CO2-treated DBH), T4 and T5 (20% and 30%, respectively, fat replacement with hexane-treated DBH), were formulated. Physicochemical properties, sensory traits and storage stability of the control and RFFs were investigated. T3 had highest native proteins (18.50 g/100 g) resulting in increased viscosity, emulsion stability, hardness and redness (a⁎) with lowest energy value and cooking loss. T2 showed better sensory attributes than the control and other RFFs. Incorporation of SC-CO2-treated DBH in frankfurter by replacing fat led to higher oxidative stability and lower microbial content during storage than the control, T1, T4 and T5.

The Effects of Natural Antioxidants on Protein Oxidation, Lipid Oxidation, Color, and Sensory Attributes of Beef Patties during Cold Storage at 4℃.

This study aimed to investigate the use of golden thread extract (GTE), clove extract (CE), and commercially available nitrite for retarding lipid and protein oxidation and for maintaining color stability and sensory attributes in beef patties stored at 4℃. GTE, CE, and nitrite treatment samples were found to be efficient in retarding lipid oxidation as all three treatments resulted in low thiobarbituric acid reactive substance (TBARS) content (p<0.05). By using GTE, CE, and nitrite into beef patties, protein oxidation was not developed. Incorporation of GTE and CE into beef patties maintained color stability by protecting against the decrease of L*, a*, b*, chroma, and hue angle values and exhibited significant influence on sensory characteristics, including color and odor of beef patties (p<0.05). Compared to commercially available nitrite, GTE and CE were more effective as antioxidants for inhibiting lipid oxidation, and preserving color stability of fresh beef patties. The study indicated that GTE and CE could be utilized efficiently to extend the shelf life of beef patties.

The Quality Improvement of Emulsion-type Pork Sausages Formulated by Substituting Pork Back fat with Rice Bran Oil.

The effects of pork back fat (PBF) substitution with various concentrations of rice bran oil (RBO) (50%, 45%, 40% and 35%) on the physicochemical characteristics and sensory attributes of emulsion-type pork sausages were studied. The modified pork sausages were compared with control sausages produced using PBF only. The sausages with RBO had significantly lower (p<0.05) moisture content than the control sausages. Sausages made from PBF substituted with 40% RBO showed the lowest cooking loss. Substitution of PBF with RBO had no significant effect on the emulsion stability of pork sausages. All sausages with RBO showed significantly lower (p<0.05) hardness values than control sausages. Sausages with RBO also had significantly higher values (p<0.05) of unsaturated fatty acid and polyunsaturated to saturated fatty acid contents than the controls. RBO substitution had no effect on the flavor intensity of sausages, but it improved the tenderness and produced a softer texture.

Effects of aging/freezing sequence and freezing rate on meat quality and oxidative stability of pork loins.

The aim of this study was to evaluate the effect of aging/freezing sequence and freezing rate on quality attributes and oxidative stability of frozen/thawed pork loins (M. longissimus lumborum, n = 6). Six treatments were prepared by combining 3 aging/freezing sequences (FT, freezing/thawing only; AFT, aging prior to freezing/thawing; and FTA, freezing/thawing and aging) with 2 freezing rates (slow- and fast-freezing). The lowest purge/thaw loss and drip loss were found for AFT, in which fast-freezing reduced total exudate loss (P < 0.05). Aging combination (AFT/FTA) decreased shear force of frozen/thawed pork loins, and FTA with slow-freezing caused the lowest shear force (P < 0.05). However, aging combination regardless of the sequence accelerated discoloration and lipid/protein oxidation during display (P < 0.05). This study suggests that aging prior to freezing coupled with fast-freezing could be an effective way to minimize quality defects of frozen/thawed only meat, particularly water-holding capacity and tenderness.