Enhancing pork loin quality attributes through genotype,chilling method and ageing time

The experiment was conducted to examine opportunities for enhancing pork quality through the use of post-mortem ageing when combined with different chilling regimes. Large White (LW, n = 24) and Duroc × Large White (Duroc, n = 24) barrows were slaughtered and alternate carcass sides were either conventionally or blast-chilled. The longissimus thoracis et lumborum muscle was dissected from the carcass sides (24 h post-mortem) and trimmed of cover fat. Three sections (15 cm length) were vacuum packaged and assigned to 2, 7 or 14 days of ageing (2 °C) randomized within muscle location. Blast-chilled meat had lower purge (P = 0.009) and drip (P = 0.0009) losses and higher hue (P = 0.02) than conventionally chilled meat. However chilling by conventional or blast-chilling methods had no effect on sensory characteristics (P > 0.1). When breeds were compared, meat from Duroc barrows had lower moisture (P < 0.0001) and higher intramuscular fat content (P < 0.0001), L∗ (P = 0.0003) and hue (P = 0.007) values than LW. Overall tenderness (P = 0.005), juiciness (P = 0.0007) and palatability (P < 0.0001), as well as flavour intensity (P < 0.0001) and desirability (P < 0.0001) values were higher and undesirable flavours were lower (P < 0.0001) for meat from Duroc pigs, when compared with LW. Ageing increased purge loss (P < 0.0001), L∗ (P < 0.0001), hue (P < 0.0001), chroma (P < 0.0001) and content of protein (P = 0.002), with corresponding decreases (P < 0.0001) in drip loss and moisture content. Instrumental (P < 0.0001) and sensory (initial, P < 0.0001 and overall, P < 0.0001) tenderness increased from day 2 to 14. Therefore independent of chilling method, ageing improved quality of pork loins. Moreover ageing had greater effect on tenderness, while breed had greater effect on flavour which may be related to differences in intramuscular fat content.     

Effect of bamboo salt on the physicochemical properties of meat emulsion systems

This study was conducted to determine the effects of various bamboo salts on meat batter. To accomplish this, three different batters were prepared and compared: CON, which was prepared with NaCl, BS-2, which was prepared with bamboo salt that was baked twice, BS-9, which was prepared with bamboo salt that was baked nine times. The pH of both the uncooked and cooked BS-2 and BS-9 was higher than that of the CON (P < 0.05). The emulsion stability, cooking yield, water holding capacity (WHC) and apparent viscosity of BS-2 and BS-9 were higher than those of CON. The correlation coefficient between the viscosity value and WHC was high and positive (R² = 0.672). The hardness of all treatments was significantly increased with increased cooking temperature (P < 0.05). The hardness, gumminess and chewiness of CON were higher than that of BS-9 and BS-2. The overall acceptability score between CON and BS-9 was significantly different (P < 0.05). The bamboo salts effectively improved the physicochemical properties of the meat batter.     

Carcass and meat palatability breed differences and heterosis effects in an Angus-Brahman multibreed population

Additive genetic Angus-Brahman differences, heterosis effects, and least squares means for six carcass and six meat palatability traits were estimated using data from 1367 steers from the Angus-Brahman multibreed herd of the University of Florida collected from 1989 to 2009. Brahman carcasses had higher dressing percent (P < 0.0001), lower marbling (P < 0.0001), smaller ribeye area (P < 0.0001), and less fat over the ribeye (P < 0.0001) than Angus carcasses. Brahman beef was less tender (P < 0.0001), had more connective tissue (P < 0.0001), and it was less juicy (P < 0.001) than Angus beef. Heterosis increased hot carcass weight (P < 0.0001), dressing percent (P < 0.017), ribeye area (P < 0.0001), fat over the ribeye (P < 0.0001), and kidney, pelvic, and heart fat (P < 0.01) in Angus-Brahman crossbred steers. Results indicated that crossbred animals with up to 50% Brahman showed limited negative impact on meat quality while maximizing meat yield due to heterosis.     

Effect of concentrate feeding on instrumental meat quality and sensory characteristics of fallow deer venison

Venison from twenty four hybrid fallow deer does, 36 months old with an initial body condition score (BCS) of 2, was tested to determine the influence of feed type on meat quality. Feeding with concentrates increased BCS (P < 0.01) but did not affect ultimate pH (P > 0.05). BCS 4 animals had higher intra muscular fat (IMF) (P < 0.01), and more tender meat (P < 0.05). Venison from does fed over 24 weeks exhibited less redness (P < 0.01) than those fed for 19 weeks regardless of feed type.Panellists evaluated samples for colour, flavour, tenderness, juiciness and overall liking. They detected significantly (P < 0.05) stronger flavour in meat from animals fed concentrates. Male panellists detected flavour differences within meat from animals fed concentrates (P < 0.05), with longer feeding periods resulting in stronger flavour. There was no difference in overall liking, therefore finishing fallow deer on grain-based concentrate feeds prior to slaughter provided little commercial advantage.     

Effect of dietary soybean oil addition on the odd-numbered and branched-chain fatty acids in rabbit meat

The effect of dietary soybean oil (SO) inclusion (20 g/kg) on the odd-numbered (ONFA) and branched-chain (BCFA) fatty acids (FA) of two muscles, differing in fatness (Longissimus lumborum and Biceps femoris), was studied in 24 New Zealand × Californian rabbits. The increased muscle fatness in Biceps femoris (P < 0.001) was related to higher saturated (P < 0.01) and monounsaturated (P < 0.01) fatty acids. Intramuscular ONFA and BCFA contents were not affected, but their proportions were reduced (P < 0.01 and P < 0.001) by SO addition, suggesting a dilution effect of the dietary polyunsaturates accumulated in both muscles, except for 17:0i which decreased only in Longissimus lumborum due to significant (P < 0.05) soybean oil × muscle interaction. The higher (P < 0.05) BCFA contents and the FA profile in Biceps femoris were not affected by fatness, indicating an association with other muscle properties. The present study supplies new information on ONFA and BCFA in rabbit meat.     

CO2 stunning procedure on Manchego light lambs: Effect on meat quality

This study examined the effect of different gas stunning methods (concentration of CO₂/time of exposure (G1: 80%90s; G2: 90%90s; G3: 90%60s; G4: 80%60s) on the initial meat quality of Manchego breed light lambs (25 kg live weight) and at 7 days post-mortem, assessed by pH, colour coordinates, water holding capacity (WHC), cooking loss (CL), drip loss (DL) shear force (SF) and lipid oxidation. An electrically stunned control group (G5) was used. Stunning method had a significant effect on pH values (P < 0.001) as well as on pH decline (P < 0.01). The lowest pH was found at 24 h post-slaughter in G1 and the highest one on G5. The greatest drop in pH (pH₀–pH₂₄) was found in G1 and G5 while the smallest in G3. In general values of colour coordinates, WHC and DL were similar in all groups. Stunning method affected CL (P < 0.001) at 7 days post-slaughter, with the lowest values being found in G1. Significant differences among groups were found (P < 0.05) in SF values at both post-mortem times, with less tender meat in groups stunned with 80% CO₂, especially in G1. A significant effect (P < 0.001) due to the type of stunning was found at 24 h on lipid oxidation, with the highest value in G5. After ageing this parameter was lowest (P < 0.05) in G1 and G4.     

Effect of production system on carcass measurements and meat quality of Kivircik lambs

Effect of production system on carcass and meat quality was investigated in four groups of lambs: i. W-C lambs were weaned between 45 and 60 days of age and then were fattened with concentrate feed until slaughter; ii. W-G-S lambs were weaned and then taken to pasture and wheat stubble; iii. UW-C lambs were fattened with concentrate feed and they suckled their dams until slaughter; iv. UW-G lambs were kept with their dams and were taken to pasture in the day-time. Hot carcass weight was 13.62, 12.52, 14.37 and 13.88 kg (P < 0.001), and dressing percentage was 55.24, 51.77, 57.83 and 55.38% (P < 0.001), for W-C, W-G-S, UW-C and UW-G lambs, respectively. Ultimate meat pH was higher in W-G-S lambs than lambs from W-C and UW-C systems (P < 0.05). W-G-S lambs had higher shear force value in longissimus dorsi muscle (P < 0.05) and lower meat lightness (P < 0.001) than those of other systems. Panellists gave the lowest sensory scores, except juiciness, to meat of W-G-S lambs.     

Effects of stunning with different carbon dioxide concentrations and exposure times on suckling lamb meat quality

Forty-nine Manchega breed male suckling lambs were used to determine the effect of different stunning methods (using two different CO₂ concentrations and exposure times) on lamb meat quality. The lambs were allocated to five stunning treatments including four CO₂ treatments [80% CO₂ for 90 s (G1); 90% CO₂ for 90 s (G2); 90% CO₂ for 60 s (G3); 80% CO₂ for 60 s (G4)] and an electrically stunned control group (G5). The gas-stunning treatments did not cause neither haematomas nor blood splash in the carcasses. Meat quality was evaluated by testing pH, colour (L^∗, a^∗, b^∗, chroma, hue values), water holding capacity (WHC), cooking loss (CL), shear force (SF), drip loss (DL) and total aerobic bacteria. Statistical differences in pH at 24 h post-mortem, colour, WHC and CL were not found among groups. After 7 days post-mortem, there were statistical differences among groups in pH (highest in G4 and G5) and in DL (highest in G1). There were differences in SF due to stunning method evident after 72 h and 7 days ageing. The statistical differences (P < 0.01) among groups on total aerobic bacteria at 24 h (lower and higher values in G2 and G5, respectively) disappeared at 7 days post-mortem. As G2 as G3, could be recommended to stunning suckling lambs since a highest stability with ageing time on meat quality was found using 90% CO₂.     

Intramuscular fatty acid composition of “Galician Mountain” foals breed: Effect of sex,slaughtered age and livestock production system

The effects of sex, slaughtered age (9 vs. 12 months) and livestock production system (freedom extensive system vs. semi extensive system) of “Galician Mountain” foals breed on the fatty acid composition were studied. The sex and slaughtered age of the animals had no statistical significance in the intramuscular fatty acids. Furthermore, the livestock production system showed differences in the fatty acid profiles from the Longissimus dorsi. The feeding system showed significant differences in PUFA content (P < 0.001) higher in freedom extensive production system that semi extensive system, whereas MUFA content was significantly (P < 0.001) higher in semi extensive system. This major PUFA content in freedom extensive production showed a significant (r = 0.70, P < 0.01) correlation with C18:3n− 3 content and can be attributed to their eaten only pasture until slaughtered. The higher MUFA contents (P < 0.001) observed for semi extensive production system foals were very significant (r = 0.98, p < 0.01) correlated with C18:1cis−9 content and less significant (r = 0.81, P < 0.01) correlated with C16:1cis−9 content. In addition, the data reinforced the evidence that foals from extensive production system on wood pasture have a higher nutritional quality (mainly due to the higher levels of n−3 PUFA) when compared to concentrate-fed foals, as a result of the beneficial effects of grass on meat fatty acid profiles.     

Evaluation of the effects of selected plant-derived nutraceuticals on the quality and shelf-life stability of raw and cooked pork sausages

The effect of lutein (200 μg/g meat), sesamol (250 μg/g meat), ellagic acid (300 μg/g meat) and olive leaf extract (200 μg/g meat) on total viable counts (TVC), pH, water holding capacity (WHC), cooking loss, lipid oxidation (thiobarbituric acid-reactive substances, TBARs), colour stability, texture and sensory evaluation of fresh and cooked pork sausages stored in aerobic or modified atmosphere packs (MAP) was investigated. Addition of sesamol, ellagic acid and olive leaf extract reduced (P < 0.001) lipid oxidation in all packaged raw and cooked pork sausages. Antioxidant potency followed the order: sesamol 250 > ellagic acid 300 > olive leaf extract 200 > lutein 200 for both raw and cooked pork sausages. Addition of sesamol increased (P < 0.001) WHC on days 2 and 12 of MAP storage. Meat addition of lutein, sesamol, ellagic acid and olive leaf extract had no detrimental effect on pH, cooking losses, TVCs, tenderness, juiciness, texture or product flavour. Lutein, sesamol, ellagic acid and olive leaf extract were effective as natural functional ingredients in suppressing lipid oxidation and have the potential to be incorporated into functional raw and cooked pork sausages.     

Effects of stress by unfamiliar sounds on carcass and meat traits in bulls from three continental beef cattle breeds at different ageing times

One-hundred-and-twenty-four young bulls of three Continental beef cattle breeds were used to study the effect of pre-slaughter stress by unfamiliar sounds on carcass traits and quality characteristics of beef aged for three different periods. Stress due to unfamiliar noises had a moderately negative effect on carcass and meat quality. Carcasses from group Stressed had higher (P < 0.05) values of pH₀, pH₂₄, a*, and Warner-Bratzler shear force, and lower (P < 0.05) values of L*, b* and pressure losses than from Unstressed animals. There were significant differences (P < 0.05) among breeds in L*, a* and pressure losses. The ageing time had a significant effect on chromatic variables, WBSF and pressure losses. The cooking losses were not significantly affected by any of the three factors discussed. These results emphasize the importance of implementing appropriate management practices during pre-slaughter handling of cattle in order to reduce any possible risk factor for stress, as well as the different sensitivity of the breeds to similar stimuli.     

High pressure induced changes on sarcoplasmic protein fraction and quality indicators

The combined effect of pressure and mild temperature treatments on bovine sarcoplasmic proteins and quality parameters was assessed. M. longissimus dorsi samples were pressurised in a range of 200–600 MPa and 10–30 °C. High Pressure Processing (HPP) induced a reduction of protein solubility (p < 0.001) compared to non-treated controls (NT), more pronounced above 200 MPa. HPP at pressures higher than 200 MPa induced a strong modification (p < 0.001) of meat colour and a reduction of water holding capacity (WHC). SDS–PAGE analysis demonstrated that HPP significantly modified the composition of the sarcoplasmic protein fraction. The pressurisation temperature mainly affected protein solubility and colour; a smaller effect was observed on protein profiles. Significant correlations (p < 0.001) between sarcoplasmic protein solubility and both expressible moisture (r = −0.78) and colour parameters (r = −0.81 to −0.91) suggest that pressure induced denaturation of sarcoplasmic proteins could influence to some extent WHC and colour modifications of beef. Changes in protein band intensities were also significantly correlated with protein solubility, meat lightness and expressible moisture. These results describe the changes induced by HPP on sarcoplasmic proteins and confirm a relationship between modification of the sarcoplasmic protein fraction and alteration of meat quality characteristics.     

Meat quality and lipid profiles in crossbred lambs finished on clover-rich pastures

Meat quality traits were compared in Texel x Polwarth and Texel x Corriedale ram lambs, with live weight of 25 kg, finished on pastures rich in white clover. The two crossbred groups showed similar results (P > 0.05) for pH, moisture, protein, meat color, individual SFA and total SFA. Fat content was higher and cholesterol lower in Texel x Polwarth lambs (P < 0.05), which also had higher amounts of MUFA (P < 0.05) and lower levels of total PUFA and n− 6 PUFA (P < 0.01). Differences in meat quality among the two crossbred groups were minor, and possibly not perceptible from the consumer standpoint. However, both groups of lambs produced lean meat with high amounts of PUFA (> 16%), possibly due to the ingestion of white clover in the finishing period. Overall, these results indicate that a differentiated product can be obtained in these conditions, with higher nutritional value than conventional lamb meat.     

Comparison of meat quality between eland (Taurotragus oryx) and cattle (Bos taurus) raised under similar conditions

Physical, chemical and sensory characteristics of meat were compared between non-domestic eland (Taurotragus oryx) bulls (n = 6) and domestic Fleckvieh (Bos taurus) bulls (n = 6) which were finished under controlled conditions of feeding and management. Musculus longissimus lumborum from eland were darker and less yellow in colour, with a higher pH₂₄ and lower contents of intramuscular fat and total collagen, compared to cattle. Contents (mg/100 g muscle tissue) and proportions (g/100 g of FA determined) of SFA and MUFA were higher (P < 0.01) in cattle. Although the proportion of total PUFA were higher (P < 0.001) in eland, contents of PUFA were similar between species. Meat from cattle was consistently scored higher (P < 0.05) for sensory texture characteristics, juiciness, flavour, and overall acceptance. We concluded that bulls of eland provided low-fat meat with a beneficial fatty acid composition from a human nutrition perspective, but with lower sensory scores, compared to bull beef.     

Effects of succinate and pH on cooked beef color

Two experiments were conducted to assess the effects of succinate and pH on cooked beef color. In experiment 1, ten strip loins (M. longissimus lumborum) were divided in half and assigned to either non-enhanced control or 2.5% succinate. Each half-loin was cut into steaks, packaged in vacuum or 80% oxygen, and stored at 1 °C for 0, 6, or 12 days. Steaks were cooked to either 66 °C or 71 °C. Succinate increased (P < 0.05) steak pH, raw a* values, and interior cooked redness when packaged in high oxygen. In experiment 2, to assess the role of succinate in raw and cooked color, succinate or ammonium hydroxide was added to ground beef patties to result in a common meat pH (5.9). At a similar pH, succinate had greater metmyoglobin reducing activity and internal cooked redness compared with ammonium hydroxide (P < 0.05). In addition to ingredient-based changes in muscle pH, succinate may influence color by regenerating reducing equivalents.     

Increasing omega-3 levels through dietary co-extruded flaxseed supplementation negatively affects pork palatability

To clarify the impact of feeding co-extruded flaxseed on carcass quality and pork palatability, 96 pigs (48 barrows and 48 gilts) were fed three different levels of flaxseed (0%, 5% and 10% of dietary intake) for 76 days. Carcass quality and meat quality characteristics of pure loin muscle and ground pork (20% fat) were evaluated. Fat hardness and belly firmness decreased (P < 0.001) with increasing co-extruded flaxseed. Pigs fed co-extruded flaxseed levels had higher lean yield (P = 0.045) and total lean content (P = 0.034). Loin from barrows had higher fat content compared to gilts (P < 0.001). Co-extruded flaxseed supplementation increased (P < 0.001) omega-3 content in loin and ground pork. Pork flavour intensity and off-flavour intensity scores lowered (P < 0.001) with increasing levels of co-extruded flaxseed, being more accentuated (P = 0.023) in reheated pork chops from barrows. Diet affected all texture and flavour sensory characteristics (P < 0.05) as tissue levels of omega-3 fatty acids increased, likely as a result of increased lipid oxidation.     

Microstructure alterations in beef intramuscular connective tissue caused by hydrodynamic pressure processing

Scanning electron microscopy (SEM) was utilized to evaluate microstructural changes in intramuscular connective tissue of beef semimembranosus muscle subjected to hydrodynamic pressure processing (HDP). Samples were HDP treated in a plastic container (HDP-PC) or a steel commercial unit (HDP-CU). Control and HDP samples were obtained immediately post-treatment and after 14 days of aging for SEM and Warner–Bratzler shear force (WBSF) analysis. Immediately post-treatment, HDP treated samples exhibited lower (P < 0.01) WBSF than did controls. After aging, HDP-PC samples had lower (P < 0.01) WBSF than that of aged controls. SEM analysis indicated that HDP-PC treatment disrupted the integrity of the collagen fibril network of the endomysium in both the non-aged and aged samples. Aging effects on the intramuscular connective tissue were observed in the HDP-PC and control samples. Both WBSF and connective tissue changes were greater in the HDP-PC than in the HDP-CU treated samples. Data suggest that shockwave alterations to connective tissue contribute to the meat tenderization of HDP.     

SmartStretch™ technology. III. The impact of medium voltage stimulation and SmartStretch™ technology on sheep topside (m. semimembranosus) meat quality traits under commercial processing conditions

This study evaluated the interaction between medium voltage electrical stimulation, SmartStretch™ stretching and ageing treatments on key meat quality traits of hot boned sheep m. semimembranosus. Medium voltage stimulation reduced initial pH (P < 0.001), but did not impact on other meat quality traits. There was a significant interaction between stretch treatment and ageing (P < 0.001) for shear force such that samples which were both stretched and aged were the most tender. Sarcomere length was significantly (P < 0.001) increased by SmartStretch™ treatment. Control (no stretching) resulted in greater (P < 0.05) cooking loss, but there was significantly less purge loss (P < 0.05). The ratio 630/580 nm and a* colour values at 0 and 5 days decreased at a significantly (P < 0.05) slower rate when SmartStretch™ was applied. Overall medium voltage stimulation did not inhibit the effectiveness of the SmartStretch™ treatment. The SmartStretch™ treatment provided significant improvement in tenderness and the potential to increase meat display time.     

Effect of a brown seaweed (Laminaria digitata) extract containing laminarin and fucoidan on the quality and shelf-life of fresh and cooked minced pork patties

A spray-dried seaweed extract containing laminarin (L, 9.3%) and fucoidan (F, 7.8%) (L/F extract) from brown seaweed (Laminaria digitata) was added directly to minced pork (M. longissimus dorsi) (LD) at levels of 0.01%, 0.1% and 0.5% (w/w). Fresh and cooked minced pork patties were stored in modified atmosphere packs containing 80% O₂:20% CO₂ and 70% N₂:30% CO₂, respectively, for up to 14 days at 4 °C. The L/F extract reduced the surface redness (‘a*’ values) of fresh patties as a function of concentration. The L/F extract (0.5%) exerted the greatest lipid pro-oxidant activity in fresh patties. The L/F extract (0.5%) significantly decreased (P < 0.05) lipid oxidation in cooked patties. The L/F extract had no effect on the microbiological status, pH, water holding capacity (WHC) or cook loss of patties. Pork patties containing 0.01% L/F were preferred by sensory panellists. Further research will focus on the use of refined purified seaweed extracts in functional meat products.