Effect of season on color of Hanwoo (Korean native cattle) beef

A total of 1278 head of Hanwoo (Korean native cattle) slaughtered over four seasons were used to evaluate the effect of season on color characteristics of beef longissimus dorsi (LD) muscle. CIE L^*, a^*, b^*, C^* values and hue angle were significantly lower (P<0.05) in cattle slaughtered in the winter season. Meat color was darker in the winter than in the spring and autumn seasons. The L^* values among three average daily temperature (T_a) categories were different (P<0.05) in order of: [5 °CT_a<25 °C] > [T_a25 °C] > [T_a<5 °C], indicating that the meat color of cattle slaughtered at T_a<5 °C was darker. The a^*, b^*, C^* values and hue angle were significantly lower (P<0.05) in cattle slaughtered at T_a<5 °C. Season at slaughter is of great importance for meat color. Namely, meat color of Hanwoo beef was influenced by environmental temperature. Overall, cattle slaughtered in the winter season of T_a<5 °C produced beef with more undesirable meat color properties.     

Nonenzymic browning during storage of white hard grape pekmez (Zile pekmezi)

Effects of storage period on hydroxymethylfurfural, pH and colour were studied in white hard grape pekmez (Zile pekmezi), a Turkish traditional product. Pekmez samples were stored at 20 °C for 8 months. Analysis of variance revealed significant differences in hydroxymethylfurfural, pH, L, a and b values (P<0.01) based on storage time.     

Storage and packaging effects on sensory and color characteristics of ground beef

Effects of irradiation (2 kGy) of ground beef patties from trimmings stored aerobically for 0 or 6 days on lean color, odor, and sensory attributes were investigated. Beef trimings were coarse ground and split into 2 groups. Group one was fine ground, pattied, and packaged immediately; group-two was stored 6 days then fine ground, pattied, and packaged. Irradiated beef patties had greater (P<0.05) off-odors, and off-flavors, lower (P<0.05) CIE L^*, a^* and b^* and saturation indexes values (P<0.05) after four days of storage at 0±1 °C. Irradiation of patties produced from trimmings aged an extra 6 days resulted in increased (P<0.05) saturation indexes and b^* values, but not off-odors when compared to non-aged and irradiated patties. Thus, the production of irradiated beef patties should utilize beef trimmings with the shortest postmortem aging time and a dose of less than 2 kGy to minimize discoloration and off-odors.     

Effect of stunning conditions on occurence of PSE defects in hams of rn+/RN(-) pigs

Pigs of the same genetic type at the RN and HAL loci, i.e. rn⁺RN⁻/NN were reared in similar conditions of feeding and housing. They were slaughtered in two abattoirs (referred to as A1 and A2) using a mixture of air (30%) and CO₂ (70%), at a rate of 300 pigs per hour per slaughterline. One hundred and thirty-two pigs from 11 farms were slaughtered in A1 using a corusinga restrainer and 127 pigs from 5 farms were slaughtered in A2 with the backloading technique. pH at 40 min, 2.5 h and 24 h after slaughter and colour (L*, a*, b*) at 24 h after slaughter were measured in the semimembranosus muscle. Meat quality of the ham was scored as follows: 1, no PSE-zone; 2, doubtful; 3, PSE-zones in the semimembranosus and sometimes on the internal flexor muscles; 4, PSE-zones in all the flexor muscles. The muscle pH value was higher in A2 than in A1 at 40 min post mortem (P<0.01), but not at 2.5 and 24 h. L* (P<0.001) and b* (P<0.05) were higher in A1 than in A2. There was a remarkable difference in meat quality scores, with 50% of the hams scoring 3 or 4 in A1, vs 13% in A2. Lairage time before slaughter affected (P<0.01) the pH value at 2.5 h (5.69 vs 5.93). The values of pH1 and pH2.5 decreased with increasing the meat quality score. The values of L* and b* increased markedly with the score. The results of the present study indicate that the method of bringing the slaughter pigs to the stunning device affects the frequency and importance of PSE meat in the ham. The automated driving of groups of animals to the stunning machine combined with the backloading of a nacelle, compared to a traditional system driving pigs in single file using electrical goads and a restrainer was beneficial with respect to both meat quality and animal welfare.     

Quality properties of pork sausage prepared with water-soluble chitosan oligomer

Emulsion type sausage was prepared with the addition of a chitosan oligomer (molecular weight 5000, 0.2%) and compared to a control. Sausages were aerobic- or vacuum-packaged and stored in a 4°C refrigerator for 3 weeks. Difference of microbial growth between the sample with added chitosan oligomer or control was not observed (P>0.05). Lipid oxidation was lower in the sausage with chitosan oligomer at 3 weeks in aerobic packaging (P<0.05) than in the control sausage. The surface color of the sausage with chitosan oligomer had higher Hunter color L*- and b*-value. Hunter color a*-values were lower in the chitosan oligomer-added sausage and the a*-value increased during storage regardless of packaging (P<0.05). Sensory panels did not detect any difference in color, flavor, texture, and overall acceptance, and mechanical texture analysis also showed no difference. Therefore, the quality of the sausage with added chitosan oligomer (0.2%) was acceptable.     

Effects of halothane gene and pre-slaughter treatment on meat quality and welfare from two pig crosses

Pigs from crosses of a Piétrain (Pi) and a Large White×Piétrain (LwPi) heterozygous (Nn) boar lines with Landrace×Large White homozygous negative (NN) sows, were used to study the effect of halothane gene and pre-slaughter treatment on animal welfare and meat quality. A total of 83 gilts (47 NN and 36 Nn) were assigned to a long treatment (3 h 15 min transport and 12 h lairage) and 73 (39 NN and 34 Nn) to a short treatment (30 min transport and 2 h lairage). Heart rate was recorded throughout loading and transport. Blood samples were collected before loading, after transport, and at exsanguination to measure cortisol, creatine phospho-kinase (CPK) and lactate dehydrogenase (LDH). Carcasses were classified and commercial cutting was carried out. Meat quality was assessed on the Longissimus thoracis muscle by measuring electrical conductivity (PQM), colour (Minolta CR 200 and Japanese scale) and ultimate pH. Loin drip losses were assessed at 24 h. Halothane carriers showed a higher increase in cortisol levels after transport and exsanguination in the long treatment (P<0.05) as well as in LDH and CPK after exsanguination in the short treatment (P<0.05). In this treatment, halothane-free pigs recovered during lairage when comparing LDH and CPK increases after exsanguination to their increases after transport. No effect of the halothane gene on heart rate was observed. Pi sired pigs were leaner and had higher yields of leg and loin compared with LwPi sired pigs (P<0.001), but no differences in meat quality were observed between crosses. Halothane carriers had a higher estimated lean content (P<0.01) and shoulder and leg yields (P<0.01), but poorer meat quality than non-carriers (i.e. higher incidence of PSE meat, P<0.001). Although pre-slaughter treatment and halothane genotype did not significantly affect pHu, significantly higher L*, a* and b* values found in the short treatment and Nn individuals indicated paler meat. These results suggest that for improving meat quality and welfare the halothane gene should be removed from breeding schemes.     

Comparative effect of low levels of dietary cobalt and parenteral injection of vitamin B(12) on carcass and meat quality characteristics in Omani goats

The effect of low levels of dietary cobalt (Co) on carcass and meat quality characteristics were investigated in 36 male goats of three different Omani breeds namely Batina, Dhofari and Jabal Akdhar. Goats were randomly divided into two groups at 10 weeks of age, control (18 animals) and treated (18 animals). Goats from both groups were fed Rhodesgrass hay and a commercially prepared diet containing 0.10 and 0.12 mg Co/kg DM, respectively from 10 to 46 weeks of age. Animals in the treated group were supplemented with subcutaneous injections of 2000 μg of hydroxocobalamin (vitamin B₁₂) on week 10 and thereafter for 46 weeks at 8-week intervals. At 46 weeks of age, the animals were slaughtered and their carcass and meat quality characteristics compared. Serum vitamin B₁₂ levels were significantly higher in goats from the treated group from week 16 till the end of the experiment. The final live and carcass weights were significantly higher (P<0.05) for the treated Batina group by 13.4 and 8.3% compared with the control group, respectively. Shoulder, rack, loin and leg cut weights were also significantly higher (P<0.05) for the Batina treated group compared with the control group by 14.7, 16.8, 12.8 and 13.1%, respectively. Carcass length, leg length, width behind shoulder, maximum shoulder width and longissimus muscle area were significantly higher (P<0.05) for the Batina treated breed than for the control group by 6.7, 5.8, 10.1, 10.1 and 28.5%, respectively. Four muscles (Mm. longissimus dorsi, biceps femoris, semimembranosus, and semitendinosus) from treated and control groups were evaluated for ultimate pH, expressed juice, cooking loss%, colour (L*, a* and b*), and Warner–Bratzler shear force values. There were significant treatment effects on these muscle quality characteristics for the Batina breed only. Muscles from the treated group showed significantly lower (P<0.05) shear force values of between 15 and 27% than those from the control group. Moreover, the treated Batina goats tended to have significantly lower (P<0.05) ultimate pH, expressed juice, L* and higher a* values than those from the control group for longissimus dorsi and biceps femoris muscles only.     

Effect of electrical stunning on meat quality of lamb

The effects of stunning on both initial and up to 2 weeks post mortem storage meat quality of Spanish Manchega breed lamb were studied. Twenty-four lambs were distributed into two groups. The first group (US; n =12) were slaughtered without previous stunning. In the second group (ES; n =12) animals were electrically stunned. Meat quality was assessed by examining pH, colour as L*, a*, b* values, water holding capacity (WHC) and shear force (SF). Stunning did not affect any parameter studied in the first 24 h post mortem. There were increasing differences between groups in pH (P<0.001) from 5 days onwards. In general stunning did not have an effect on WHC, SF and colour parameters. Ageing of meat affected SF in the ES group but not in the US one; however, there were no significant differences between treatments at any of the ageing times.     

High voltage electrical stimulation enhances muscle tenderness, increases aging response, and improves muscle color from cabrito carcasses

Our study examined high and low voltage electrical stimulation and postmortem storage as strategies to improve tenderness and lean color in cabrito carcasses. Boer cross (n=60) kids were assigned to either high (550 V), low (20 V), or no electrical stimulation treatments. No differences in muscle temperature were observed between treatments at any time measured. Muscle pH declined fastest in high voltage treated carcasses. High voltage electrical stimulation slightly increased (P<0.05) b^* and a^* in the M. gluteus medius and tended to increase L^* and b^* (P=0.06 and 0.11, respectively) values in the M. longissimus thoracis. Electrical stimulation had no effect on myofibril fragmentation at 1-, 3-, or 14-d postmortem or sarcomere length. High voltage electrical stimulation increased (P<0.05) tenderness at 1- and 3-d postmortem, but not at 14-d postmortem. Aging for 3 d did not affect tenderness regardless of stimulation treatment, but aging time for 14 d improved (P<0.05) tenderness. These data indicate that high voltage electrical stimulation and 14 d aging were effective in improving the tenderness of meat from cabrito carcasses.     

Colour of normal and high pH beef heated to different temperatures as related to oxygenation

The effects of oxygenation and thermal treatment (internal temperature, T_i: 45, 60, 75°C) on the colour and some colour related physical and biochemical properties of beef longissimus dorsi (LD) muscle, both normal (pH_u5.6) and DFD (pH_u>6.6), were studied. The colour components (L^*, a^*, b^* values) for the raw and heated LD, both before and after oxygenation, were instrumentally and sensorily evaluated. The colour of raw and heated (60°C) DFD beef before and after oxygenation differed significantly from the normal meat and contained more native muscle pigment (TMP). pH also influenced the depth of the oxygenated layer, specific activity of cytochrome c oxidase (SACCO) and the amount of oxygen consumed. An increase in internal temperature was usually accompanied by a lower SACCO and a significant decrease of TMP, as well as a change of all colour parameters. Oxygenation of the raw and heated slices (except at 75°C) of both types of meat led to higher L^*, a^* and b^* values.     

Factors associated with surface iridescence in fresh beef

The objective of this study was to investigate factors associated with surface iridescence in fresh beef. Eight muscles were evaluated for occurrence of surface iridescence: Biceps femoris (BF), Gluteus medius (GM), Longissimus lumborum (LD), Psoas major (PM), Rectus femoris (RF), Semimembranosus (SM), Semitendinosus (ST), and Tensor fasciae latae (TF). Incidence of surface iridescence was 91% for ST, 34% for SM, 27% for LD, 20% for GM, 12% for RF, 9% for BF, 8% for TF, and 6% for PM (P<0.05). Factors associated with surface iridescence in the ST were further examined because iridescence was observed to a much higher degree in the ST as compared with other muscles evaluated. Greater ST surface iridescence was associated with larger ribeye areas, more youthful lean maturity scores, higher L^*, a^* and b^* colorimeter values, lower ultimate pH values, and faster cooking (P<0.05).     

Physical evaluation of popped cereal snacks with spent hen meat

Various blends of spent hen meat and grains (potato starch, corn starch, and rice flour) were popped using a popping machine. Lowest bulk density was observed in the snack with 1:2 ratio of meat and potato starch. Except for the popped snack with meat and rice flour, as the starch content increased, bulk density decreased gradually. Popped snacks with grains only were higher in L* value than those with meat and grains. The a* and b* values increased with increasing meat content. All popped snacks were significantly different (P<0.001) in bulk density, color, and breaking force. As the grain content of snacks increased, the size of the air cells also increased. Results of scanning electron microscopic and optical microscopic observations revealed the popping degree of snack with starch and spent hen meat was affected by the presence of meat. The optimum ratios of meat to grain for high expansion ratio were determined to be 1:2 and 1:3 of meat to corn starch and potato starch.     

Effects of transportation at high ambient temperatures on physiological responses, carcass and meat quality characteristics of three breeds of Omani goats

The experiment was designed to determine the effects of short road transportation in an open truck during the hot season on live weight shrink, physiological responses, carcass, and meat quality characteristics in three breeds of Omani goats. Forty-two male goats (12 months of age) representing equally three breeds of Omani goats (Batina, Dhofari, and Jabal Akhdar) were divided into two groups: 2 h transportation stress (TS) or not transported (NT). The NT group remained unstressed in holding pens with feed and water provided ad libitum prior to slaughter, while the TS group was transported on the day of slaughter 100 km in an open truck. The average temperature during transportation was 37 °C. All animals were blood-sampled before loading and prior to slaughter via jugular venipuncture. Animals were weighed just before loading onto a truck and after transport to assess shrinkage. Muscle shear force, sarcomere length, pH, expressed juice, color, and cooking loss were measured on samples from Mm longissimus dorsi (LD), biceps femoris (BF), and semitendinosus (ST) muscles collected at 24 h postmortem at 1–3 °C. Live weight shrinkage losses were between 1.07 and 1.28 kg. The TS goats had higher plasma cortisol (P < 0.01), adrenaline, nor-adrenaline, and dopamine concentrations (P < 0.05) than NS goats. Blood serum from Batina goats had significantly (P < 0.05) higher cortisol, adrenaline and dopamine and nor-adrenaline concentrations than those from Jabal Akdhar goats. Transportation stress had a significant (P < 0.05) effect on meat quality characteristics of the LD, BF, and ST muscles. Meat from TS goats had significantly higher ultimate pH, expressed juice, cooking loss percentage, shear force, but significantly lower sarcomere length, L^*, a^*, and b^* values. LD muscles of Batina goats had significantly higher ultimate pH values and lower L^* values than Dhofari and Jabal Akdhar goats. These results indicated that subjecting goats to the 2-hour road transportation with high ambient temperatures can generate major physiological and muscle metabolism responses.     

Effects of conjugated linoleic acid on color and lipid oxidation of beef patties during cold storage

The effects of conjugated linoleic acid (CLA) on color and lipid oxidation of beef patties were investigated. Ground beef was divided into three batches. The control patties were prepared with 90% lean meat and 10% tallow. The second treatment consisted of 90% lean meat with 9.5% tallow+0.5% CLA sources. The third treatment consisted of 90% lean meat with 8% tallow+2% CLA sources. The patties were wrap-packaged and then stored at 4° for 14 days. The CLA concentration significantly increased (P<0.05) by substituting CLA sources for fat. Storage of the patties did not alter the CLA concentration in beef patties. The treatment substituted with CLA sources had significantly lower TBARS (2-thiobarbituric acid-reactive substances) values (P<0.05) than the control. For oxymyoglobin contents and a* value, substituted CLA sources treatments had significantly higher values than the control. However, L* value significantly increased by substituting CLA sources for fat.     

Stunning and shackling influences on quality of porcine Longissimus dorsi and Semimembranosus muscles

Seventy-one barrows of three porcine genotypes (nn, Nn and NN genotypes with respect to halothane) were electrically stunned on the right side and randomly assigned to one of three treatments during the bleeding process (prone, PR; shackled left, SL; or shackled right, SR) to investigate the influence of both shackling and stunning on ultimate meat quality. PR carcasses had less side-to-side variation in 40 min pH than either SL or SR carcasses. Shackling contributed to a decreased 40 min pH in the semimembranosus (SM) and posterior longissimus dorsi (PL). The effects of stunning appeared to be additive when combined with shackling, tending to lower pH in the mid-longissimus dorsi (ML; P <- 0·10). The ‘free’ side of the shackled carcass also had significantly lower 40 min pH in the ML, PL and SM locations when compared to PR sides. Genotype had no influence on shackling since there was no treatment by genotype interactions. Despite significant effects on post-mortem metabolism (indicated by the differences in 40 min pH) shackling alone had little influence on overall ultimate meat quality of the carcass. Depending on the sampling location, soluble protein and L^* and b^* values varied among treatments. Shear force and a^* values were similar among treatments, but PR and SL carcasses had significantly lower expressible juice and drip loss compared to SR carcasses. These results suggest that, although shackling alone has little effect on meat quality, in combination with electrical stunning, shackling can lead to a decrease in meat quality.     

Effects of transport time and season on aspects of rabbit meat quality

The aim of this study was to determine whether transport times of up to 7 h can have a significant effect on instrumental meat quality traits in rabbits. Spain has very hot summers and cold winters; therefore, we performed replicates in two seasons. To evaluate the effect of transport time and season on rabbit meat quality, we assessed four meat quality parameters: pH, water holding capacity (WHC), texture (compression and Warner–Bratzler analyses), and colour (CIEL*a*b*). We also considered the effect of the position of the animals on the transport vehicle. After slaughter, we analysed steaks of Longissimus dorsi from all transported animals (n = 216). Average pH at 24 h and WHC did not differ significantly between transport time treatments. Position on the vehicle did not influence the measures of meat quality. Transport time had a significant effect on all the meat texture parameters measured by compression, but did not affect shear force or toughness. Transport time influenced a* but not L* or b*. Transport time had much less of an effect on meat quality than time of year; therefore the effect of season appeared to be independent of transport time. Position on the vehicle had no effect on meat quality. Based on our results, we conclude that the transport process can affect instrumental meat quality.     

Influence of outdoor rearing and indoor temperature on growth performance, carcass, adipose tissue and muscle traits in pigs, and on the technological and eating quality of dry-cured hams

The effects of restricted outdoor rearing during winter (W) or summer (S), and the influence of indoor ambient temperature [17 °C (I17) vs. 24 °C (I24), the latter being considered as control] on pig growth performance, carcass, muscular and adipose tissue traits, and technological and eating quality of dry-cured hams were evaluated. I17 pigs exhibited higher, whereas W had similar and S lower growth rates than the controls (P<0.001). Carcass traits were not different between groups, except in lower back fat weights of S and W pigs (P<0.01). Decrease in environmental temperature affected the fatty acid composition of the back fat leading to higher MUFA and lower SFA and PUFA contents (P<0.001) in I17 and W pigs, whereas S pigs exhibited higher PUFA levels (P<0.001) and fat firmness (P<0.01) than the controls. Rearing system did not significantly influence the intramuscular fat content of Semimembranosus (P=0.08), and had no effect on ultimate pH. In the Longissimus lumborum, percentage and relative area of R fibers increased in W pigs (P<0.05), but citrate synthase activity did not differ between groups. I17 and W hams exhibited higher processing yields of dry-cured hams than controls (P<0.05). Sensory analyses showed that pig rearing conditions influenced the product appearance, the I17 and W hams exhibiting lower homogeneity (P<0.01) and intensity (P<0.05) of colour, and higher marbling scores (P<0.01) than I24 hams, but had no influence on texture or flavour.     

Meat quality characteristics of springbok (Antidorcas marsupialis). 1: Physical meat attributes as influenced by age, gender and production region

Springbok is the most extensively cropped game species in South Africa. The effects of age (adult, sub-adult, lamb), gender and production region on the physical attributes (pH₂₄, cooking and drip loss, Warner Bratzler shear force and colour) were determined using samples of the M. longissimus dorsi (LD) muscles of 166 springbok. Stressed animals had a higher (P < 0.05) pH₂₄ (6.3 ± 0.07), as observed in the meat originating from the Caledon region. This meat had lower (P < 0.05) cooking loss (27.2 ± 0.62%) and drip loss (1.8 ± 0.08%) values in comparison to meat originating from the other regions. Inverse correlations were noted between pH₂₄ and drip loss (r = −0.26, P < 0.01) and cooking loss (r = −0.42, P < 0.001). Shear force values (kg/1.27 cm diameter) correlated positively (r = 0.25, P < 0.01) with pH₂₄. Age-related effects on tenderness were small in comparison with pH₂₄ effects. CIELab colorimetric values were typical of game meat and venison (L^* < 40, high a^* and low b^* values). It was noted that pH₂₄ correlated negatively (r = −0.51, P < 0.001) and positively (r = 0.33, P < 0.001) with the hue-angle and the chroma value of colour, respectively. Springbok originating from Caledon had a significantly (P < 0.05) higher a^* value, indicating meat to be more red with higher colour saturation.     

Effect of different stunning systems on meat quality of light lamb

The present study was proposed to compare the effect that different types of stunning (TS) had on the quality of refrigerated meat from light lambs of the Spanish Manchega breed at 24 h and 7 days post-mortem. Lambs were electrically stunned (ESL; n = 10), using CO₂ (GSL; n = 10) or slaughtered without previous stunning (USL; n = 10). Measurements on meat quality were carried out by evaluating pH, colour coordinates (L^*, a^*, b^*), water holding capacity (WHC), cooking loss (CL), shear force (SF) and drip loss (DL). At 24 h post-mortem, no significant differences were found in any of the variables studied. However, at 7 days post-mortem, meat quality was affected by the different TS: pH, CL and DL were lower (P < 0.001) in the USL group and GSL obtained the lowest a^* (redness) and b^* (yellowness) values (P < 0.01) than in the other groups. Ageing of meat affected SF in the ESL group (P < 0.01), although there were no significant differences due to treatments at any of the ageing times.     

Processing characteristics of beef roasts made from high and normal pH bull inside rounds

The processing characteristics of roasts manufactured from either high or normal pH bull inside rounds (semimembranosus and adductor muscles), which had been stored chilled or frozen, were investigated. Roasts were injected with a salt/phosphate brine and cooked to an internal temperature of 63 °C in a 70 °C water bath. High-pH meat that had been frozen had less purge than normal pH meat. However, pH did not affect purge from chilled meat. Meat pH and storage conditions did not affect retention of pumped brine. Cook yields were significantly (P<0.05) higher for roasts made from high pH meat (103.8 vs 98.8%). Raw and cooked meat colour was affected by meat pH but not storage condition. Cooking reduced the effect of pH on meat colour but cooked roasts manufactured from high pH meat were redder than roasts manufactured from normal pH meat.