Fresh Meat Color Research Articles

The combined effect of antioxidants and modified atmosphere packaging on protein and lipid oxidation in beef patties during chill storage

Effect of rosemary extract and ascorbate/citrate (1:1) in combination with modified atmosphere packaging (100% N 2, 80% O 2/20% N 2) on protein and lipid oxidation in minced beef patties during storage in the dark for up to 6 days at 4 °C was investigated. A high level of oxygen in the packaging atmosphere was found to increase both lipid and protein oxidation during storage as evaluated by TBARS analysis of secondary lipid oxidation products and by 2,4-dinitrophenylhydrazine derivatization of protein carbonyls. Both antioxidant systems tested were found to inhibit lipid oxidation but not protein oxidation. In contrast, ascorbate/citrate was found to promote protein oxidation. Rosemary extract was found to regenerate or protect α-tocopherol whereas the packaging atmospheres had no effect on α-tocopherol stability. In high oxygen atmospheres both antioxidants protected the fresh red meat colour with ascorbate/citrate being more efficient than the rosemary extract, whereas no effect of antioxidant on meat colour was found in beef patties stored in 100% nitrogen.

Effects of Packaging Systems on the Natural Microflora and Acceptability of Chicken Breast Meat

The effect of 3 packaging systems on the spoilage microflora, objective color, and sensory characteristics of fresh commercial broiler chicken breast meat was investigated. Fresh skinless and boneless chicken broiler breasts were purchased from a local poultry processing plant and packaged in either (1) a conventional Styrofoam tray with polyvinyl chloride overwrap and absorbent pad, (2) a Styrofoam tray with polyvinyl chloride overwrap minus absorbent pad, or (3) a Fresh-R-Pax (FRP) container equipped with an absorbent liner-gel system. All packages were heat sealed and stored at 1.2 +/- 1 degrees C for 8 d. At each sampling period (0, 2, 4, 6, and 8 d), packages from each treatment were analyzed for Pseudomonas spp., psychrotrophic organisms, objective color, and sensory characteristics. In general, Pseudomonas spp. and psychrotrophic counts increased as storage time increased for all packaging systems. Color and overall appearance were similar (P >0.05) for all packaging systems. Although not significant, the off-odor scores for breast meat packaged in FRP were higher (P >0.05) after 6 and 8 d when compared with the breast meat packaged in a Styrofoam tray with polyvinyl chloride overwrap with or without an absorbent pad. Although the absorbent pad did not control microbial growth, it maintained aesthetic appeal by absorbing all visible moisture released from the meat during storage.

Mitochondrial Reduction of Metmyoglobin: Dependence on the Electron Transport Chain

Reduction of ferric myoglobin (metmyoglobin, MetMb) to its ferrous form is important for maintaining fresh meat color because only reduced myoglobin can bind oxygen to form the consumer-preferred cherry red color in fresh meat. The objective of this study was to characterize an apparent mitochondria electron transport chain (ETC)-linked pathway for MetMb reduction in vitro. MetMb was reduced in the presence of mitochondria and succinate (p < 0.05); mitochondria or succinate alone did not facilitate MetMb reduction relative to controls (p > 0.05). Flushing samples with oxygen greatly decreased MetMb reduction, while flushing with argon increased MetMb reduction when compared with controls (p < 0.05). ETC inhibitors were used to localize the site where electrons became available for MetMb reduction. MetMb reduction was increased by rotenone addition and decreased by malonic acid (p < 0.05); the reduction was completely abolished by additions of antimycin A or myxothiazol when compared with controls (p < 0.05). These results suggest that electrons become available for MetMb reduction at a site(s) between complex III and IV. Mitochondrial ETC-linked MetMb reduction increased with increased mitochondrial density and succinate concentration (p < 0.05); the greatest MetMb reduction was observed at pH 7.2 and 37 degrees C, and ETC-linked MetMb reducing activity decreased with time postmortem (p < 0.05). These results indicate that ETC-linked MetMb reduction exists but would be minimally active in postmortem muscles.

Dietary supplementation of garlic and rosemary: effects on colour stability and lipid oxidation in lamb meat

RiassuntoIntegrazione alimentare con aglio e rosmarino: effetti sul colore e sull’ossidazione lipidica della carne di agnello. Agnelli di razza Gentile di Puglia sono stati alimentati con un mangime di base (Controllo) o integrato con aglio fresco (3,5 g kg-1), estratto di aglio (500 mg kg-1), estratto di rosmarino (500 o 1000 mg kg-1) o con vitamina E (500 mg kg-1 α-tocoferolo acetato). Sono stati costituiti due sottogruppi di agnelli macellati rispettivamente a 80 o 110 giorni. Nei giorni 1, 3, 5 e 7 successivi alla macellazione sono stati valutati il colore e l’ossidazione lipidica mediante TBARS test sul muscolo Longissimus lumborum. Il colore della carne è stato migliorato dagli antiossidanti naturali, ma soprattutto dalla vit. E (P<0,05). Il TBARS test ha evidenziato una diminuzione dell’ossidazione lipidica nei gruppi vit. E e aglio estratto (P<0,01), seguiti dal gruppo rosmarino 1000 (P<0,05). A 110 giorni si sono attenuate le differenze tra i trattamenti alimentari, ma la vit. E e l’aglio estratto hanno confermato il loro effetto antiossidante (P<0,05).

Influence of early postmortem protein oxidation on beef quality.

The objective of this study was to examine the effect of early postmortem protein oxidation on the color and tenderness of beef steaks. To obtain a range of oxidation levels, the longissimus lumborum muscles (LM) from both strip loins of 20 steers fed either a finishing diet with vitamin E (1,000 IU per steer daily, minimum of 126 d [VITE]; n = 10 steers) or fed the same finishing diet without vitamin E (CON; n = 10 steers) were used. Within 24 h after slaughter, the LM muscle from each carcass was cut into 2.54-cm-thick steaks and individually vacuum packaged. Steaks from each steer were assigned to a nonirradiated group or an irradiated group. Steaks were irradiated within 26 h postmortem, and were aged at 4 degrees C for 0, 1, 3, 7, and 14 d after irradiation. Steaks from each diet/irradiation/aging time treatment were used to determine color, shear force, and degree of protein oxidation (carbonyl content). Steaks from steers fed the VITE diet had higher (P < 0.01) alpha-tocopherol contents than steaks from steers fed the CON diet. Immediately following irradiation, steaks that had been irradiated had lower (P < 0.05) L* values regardless of diet. Irradiated steaks, regardless of diet, had lower a* (P < 0.05) and b* (P < 0.01) values than nonirradiated steaks at all aging times. Carbonyl concentration was higher (P < 0.05) in proteins from irradiated steaks compared to nonirradiated steaks at 0, 1, 3, and 7 d postirradiation. Immunoblot analysis showed that vitamin E supplementation decreased the number and extent of oxidized sarcoplasmic proteins. Protein carbonyl content was positively correlated with Warner-Bratzler shear force values. These results indicate that increased oxidation of muscle proteins early postmortem could have negative effects on fresh meat color and tenderness.

Oxidative and colour changes in meat from three lines of free-range reared Iberian pigs slaughtered at 90 kg live weight and from industrial pig during refrigerated storage

The oxidative stability and colour evolution during refrigerated storage (10 days at +4 °C) of Longissimus dorsi muscle from three lines of Iberian pigs and industrial genotype pigs were studied. The Iberian pigs were reared in an extensive system and fed on a commercial feed with access to pasture grazing, while industrial genotype pigs were reared in an intensive system. Fresh Longissimus dorsi of Iberian pig lines showed a more intense and redder colour, with a statistically significant higher CIE chroma and a*-value as well as a lower L*-value ( P<0.05) compared with those of industrial genotype pigs. Pig genotype significantly affected the colour and lipid oxidation changes of m. Longissimus dorsi during refrigerated storage. The decrease in L*-value during the refrigerated storage was more intense in industrial pig's Longissimus dorsi than in those from Iberian pig lines. CIE a*-value decrease was more intense in ‘Lampiño’ Iberian line and industrial Longissimus dorsi than in the other two Iberian pig lines, however CIE a*-value was significantly higher in muscles from Iberian pig lines than in muscle of industrial genotype ( P<0.05) at the end of refrigerated storage. The Iberian and industrial pig's Longissimus dorsi did not show statistically significant differences in TBA-RS values (mg MDA/kg meat) at the end of the refrigerated storage period ( P>0.05). To establish relationships between parameters measured in fresh meat and oxidation and colour changes during refrigerated storage, correlations and multiple regression models were calculated. CIE a*-values at day 10 were positively correlated with values of fresh muscles for a*, C18:1 percentages and negatively correlated with polyunsaturated fatty acids percentages of neutral and polar lipids. Inversely, TBA-RS values at day 10 showed a positive correlation with initial values for phospholipid content and polyunsaturated fatty acids of neutral and polar lipid fractions, while C18:1 percentage were negatively correlated.

Study on Pork Characteristics of Chinese Wuzhishan Mini-Pig

This research was conducted to evaluate the meat traits of Wuzhishan mini-pigs (WZSP). Young Xiang-pigs (XPs) and adult Beijing Black-pigs (BPs) were used as the control group of young and adult WZSPs respectively. Studies included evaluation of carcass properties, meat sensory character, edible quality and processing performance. The studies show the WZSP is of thin skin, low back-fat, high lean percentage and meat productivity. The results of meat quality analysis indicate the WZSP pork is of fresh meat color, good elasticity, less marbling, rich amino acid especially pre-flavor amino acid and low intra-muscular fat. Meanwhile, WZSP pork presents benign processing performance of low loose water percentage, low drip loss, and eminent bounding water capability.

Effects of vitamin E supplementation on lipid peroxidation and color retention of salted calf muscle from a diet rich in polyunsaturated fatty acids.

The color of fresh meat is one of the most important quality criteria of raw muscle foods. This red color is principally due to the presence of oxymyoglobin. The present study was undertaken to examine the effect of a diet rich in polyunsaturated fatty acids (PUFA), the addition of NaCl, and the influence of dietary supplementation with vitamin E on calf muscle oxymyoglobin oxidation (color) and lipid peroxidation. Vitamin E was added to the feed at a concentration of 4000 mg/day for 90 days before slaughter. This diet increased the alpha-tocopherol concentration in muscle membrane from 2.6-2.8 to 6.5-7.0 microg/g of fresh weight. It was found that the diet rich in PUFA and, especially, the addition of NaCl increased muscle lipid peroxidation and oxymyoglobin oxidation as indicated by the contents of thiobarbituric acid-reactive substances and substances that impaired color value readings during storage at 4 degrees C. Both undesirable reactions during storage were controlled very efficiently by the presence of a critically high concentration of alpha-tocopherol in the muscle tissues. The findings concerning the antioxidant activity of alpha-tocopherol in this study form additional evidence of its efficient protection against oxidative reactions during storage of muscle tissues and its potential to maintain a high nutritional value in them.

Oxymyoglobin oxidation and membranal lipid peroxidation initiated by iron redox cycle.

Oxymyoglobin is the main pigment in muscle tissues, responsible for the bright red color of fresh meat. Oxidation of the heme iron from the ferrous to the ferric metmyoglobin produces the brownish color that consumers find undesirable in fresh meat. The aim of this study was to elucidate the mechanism of oxymyoglobin oxidation in muscle tissues by using a model system containing oxymyoglobin and muscle membranes oxidized by an iron redox cycle. Oxidation of oxymyoglobin was determined from the decrease in absorption of the solution measured by a spectrophotometer at 582 nm. Lipid peroxidation was determined by accumulation of TBARS and conjugated dienes. The higher rates of oxidation of oxymyoglobin (20 microM) and lipid oxidation were achieved by using ferric iron and ascorbic acid at concentrations of 50 and 200 microM, respectively. Increasing the concentration of ascorbic acid to 2000 microM switched its effect to antioxidative. Increasing the concentration of oxymyoglobin from 20 to 80 microM inhibited lipid peroxidation by >90% and partially prevented oxymyoglobin oxidation.

Some effects of residual glycogen concentration on the physical and sensory quality of normal pH beef

The aim of this study was to assess the effects of residual glycogen concentration on the physical and sensory quality of normal-pH beef. Longissimus thoracis et lumborum muscles ( n=42) having ultimate pH (48 h) between 5.50 and 5.75 were excised, assayed for residual glycogen concentration and divided into three categories according to the residual glycogen concentration. The categories were ⩽25 mmol/kg, 25.1–49.9 mmol/kg and ⩾ 50 mmol/kg. One half of every LTL muscle was aged for 28 days. All samples were evaluated for fresh meat colour, drip loss, shear force, thawing and frying losses and fried steak colour as well as sensory attributes of tenderness, juiciness, flavour and overall palatability. The independent significant effects of increasing residual glycogen concentration on the physical and sensory quality of normal-pH-beef were, although numerous, quite modest in magnitude. The water holding variables in the form of decreasing drip loss ( p<0.061), increasing thawing loss ( p<005), increasing sum of losses in thawing and frying ( p<0.05), and decreasing sensory juiciness ( p<0.05) were somewhat affected as were decreasing fresh meat redness (Minolta a*) ( p<0.005), decreasing shear force ( p<0.05) and increasing yellowness (Minolta b*) of the steak ( p<0.0001). Beef of the lowest and highest glycogen category were the ones behaving slightly differently from each other, the intermediate category mostly followed the pattern of one or the other.

Effect of halothane genotype on porcine meat quality and myoglobin autoxidation

The objective of this study was to determine effects of light (40–80 kg) or heavy (100–130 kg) slaughter weight and halothane status (positive, nn; negative, NN; and heterozygous, Nn), on meat quality. Longissimus muscle (LM) pH at 45 min (pH 45) post-exsanguination was 6.25, 6.03, and 5.84 (different at p < 0.01) for NN, Nn, and nn genotype, respectively. At heavier weights (100–130 kg), genotype correlated ( r = −0.71) with LM pH 45, 10th costae LM (TENLM) color score ( r = −0.55), TENLM Hunter L ∗-value ( r = 0.47), water holding capacity ( r = 0.42) and TENLM subjective firmness-wetness score ( r = 0.51). Rate constants for metmyoglobin accumulation and oxymyoglobin autoxidation, indicators for fresh meat color stability, increased ( p < 0.05) with decreasing pH. Color stability for NN muscle was more stable than nn muscle ( p < 0.05). Electrofocusing of myoblobin revealed two bands (MW 17.10 3) at pI 6.1 and 6.5 across genotypes. Because differences were not observed across genotypes, an observed increase ( p < 0.05) in 24 hr myoglobin autoxidation rate constant (associated with increased expression of the HAL gene) are presumed dependent upon post-mortem muscle changes. These data show that changes in halothane status affect fresh pork quality and that lowered meat quality results in further color destruction due to altered chemical reactions involving myoglobin oxidation.

Lean colour of green and matured Parma hams: Comparative evaluation and technological relevance of sensory and objective data

Research has been conducted on the relationship between sensory evaluation and objective measurement of pork colour. The study also investigated the relationship between the colour of fresh meat and the colour of matured hams. Sensory evaluation was carried out at 24 h post mortem on the freshly cut surfaces of green hams trimmed for Parma ham production. Objective measurements were performed at the same time on Semimembranosus and Biceps femoris muscles with a Minolta Chromameter Reflectance II CR200/08. Cold carcass weight, lean content, trimmed ham weight, 45 min and 24 h post mortem pH of Semimembranosus muscle were also recorded. The hams were processed according to Parma ham technology. Weight losses at standard processing times were collected. At the end of processing a sample of about one-third of the hams was evaluated for internal lean colour and lean firmness both by sensory panel and objective measurements. Proximate composition was also determined. The results showed highly significant relationships between colour sensory scores and the coordinates L ∗, b ∗ and hue of the C.I.E. L ∗a ∗b ∗ colour system. Among the other parameters measured on fresh meat only 24 h pH was related at a very significant level with sensory and objective colour values. Correlation coefficients were generally higher for Semimembranosus than Biceps femoris. Matured ham colour was linked with fresh meat sensory judgements, L ∗ , hue and a ∗ values. The relationship, though, was not sufficiently strong for use in predicting the colour of matured hams from green ham characteristics. Processing appears to have a positive effect on the colour of pale meat. Weight losses were mainly linked with lean meat content; other quality attributes being less important. Lean firmness of matured hams was related to the colour and pH of the fresh meat.

Relationship of breast fillet deboning time to shear force, pH, cooking loss and color in broilers stunned by high electrical current

Experiments were conducted to determine the relationships between deboning time and broiler breast meat quality, as determined by objective meat tenderness, pH, color and cooking loss. All birds were processed in a European commercial processing plant using a high current, constant voltage stunning system and air chilling. According to a modified Mitscherlich response equation, pH values reached their ultimate value by 5.77 h post-mortem, with an asymptotic 95 % confidence interval of 5.72 h-5.81 h post-mortem. The shear force data, which were analyzed using a logistic model, suggested that broiler breast fillets should be aged intact on the carcass for 10.58 h, 5.94 h or 2.28 h to guarantee that over 95 % of the fillets reach Allo-Kramer shear forces of 8.0, 9.0 or 11.0 kg/g, respectively. Since acceptable meat tenderness values vary with country, geographical area, or consumer groups, acceptable ranges should be determined according to potential market demands. No relationships between deboning time and fresh meat color or cooking loss was found.

Titration of fresh meat color stability and malondialdehyde development with Holstein steers fed vitamin E-supplemented diets.

Pigment and lipid oxidations were investigated in longissimus lumborum (LL), semimembranosus (SM), and gluteus medius (GM) from Holstein steers fed four doses of vitamin E (64 [control], 295, 550, or 2,173 IU/d) for two durations (42 or 126d). Vitamin E dose did not affect (P = .30) carcass quality or yield characteristics. The LL was stored in vacuum packages at 4 degrees C for 14, 28, and 56 d, and GM and SM were stored for 14 d. Increments of dose and duration of vitamin E supplementation increased (P < .001) alpha-tocopherol concentration in blood plasma and in these muscles. During simulated retail display, accumulations of metmyoglobin (METMB) and thiobarbituric acid reactive substances (TBARS) were greater (P < .01) in beef from control than in beef from supplemented steers. In cubic models, muscle alpha-tocopherol accounted for 79% of the variation in TBARS and 66% of the variation in METMB. Color display life, calculated by the METMB threshold method, revealed fewer dose and duration effects of vitamin E than were evident following analysis of variance of the METMB responses. Across durations and muscles, color display-life of fresh beef calculated by the METMB threshold method was extended (P < .05) .9 to 1.8 d by vitamin E supplementation (P < .05). Storage for 28 or 56 d caused only a slight decline (P < .001) in LL alpha-tocopherol concentration but diminished (P < .05) vitamin E effects on color display-life. Although the ranking of alpha-tocopherol accumulation was GM > SM > LL, the color display-life ranking of these muscles across vitamin E treatments was LL > SM > GM.

THE BIOCHEMICAL BASIS FOR DISCOLORATION IN FRESH MEAT: A REVIEW

ABSTRACTThe color of fresh meat is an extremely important characteristic influencing the consumer's purchase decision. The stability of pigments in meat is highly variable and is governed by a variety of factors. The effects of exogenous factors (i.e., storage and display conditions) have been well researched. The control of these variables currently offers the best means for maximizing meat color stability. Biochemical factors which are inherent to the meat itself have received far less research attention and an understanding of these presents the greatest potential for prolonging color stability in fresh meat.

The effect of electrical stimulation, time of boning and high temperature conditioning on sensory quality traits of porcine Longissimus dorsi muscle

The effects of electrical stimulation (300 V, 1 A, 50 Hz, AC, 30 s) and high temperature conditioning (4h/15°C) on sensory quality traits of hot- and cold-boned, vacuum-packaged longissimus dorsi muscle of halothanenegative pigs were assessed at 12 days post mortem. Electrical stimulation accelerated the pH fall significantly, but had negligible effects on all quality traits measured, i.e. shear force, drip formation, fresh meat colour, cooking loss and degree of sarcoplasmic protein denaturation (p > 0·05). As compared with cold boning, hot boning significantly lowered drip losses (p < 0·05). Shear forces, which increased as a result of hot boning (p < 0·05), were reduced again through a 4 h/15°C conditioning period before chilling at 1 ±1°C. In addition, high temperature conditioning resulted in significantly lower drip losses (p < 0·05). It is suggested that prevention of cold-induced reduction of proteolytic enzyme activity is primarily responsible for both these findings.

FACTORS ASSOCIATED WITH FRESH MEAT COLOR: A REVIEW

ABSTRACT The color of fresh meat is important to every aspect of the meat industry. The basic explanations for various colors and intensities of color need to be understood in order to minimize off‐colors which ultimately result in product loss. This review discusses the various color forms of myoglobin in muscle and their relationship to species, atmospheric conditions, antemortem factors and storage characteristics.

DETERMINATION OF FRESH MEAT COLOR BY OBJECTIVE METHODS

ABSTRACTVisual impressions of fresh meat color are formed by contributions from all three parameters of color, namely, hue, value, and chroma, as well as gloss, relative pigment content, and the presence of surface moisture. It appears that there is a mental “ideal value” for each of these factors and deviations from that ideal in any direction cause the meat to be rated lower visually. Since these deviations may occur in any of the above mentioned parameters, it is difficult for instrumental methods to predict the visual color quality of fresh meats. Equations were developed which could be useful for making accept/reject decisions on pork muscle color.

Fresh meat color

This review presents a critical evaluation of the recent developments in the study of fresh meat color. Importance of color as a primary quality attribute deciding the consumer acceptance of fresh meats, is pointed out. The stability of myoglobin pigment, essential for the maintenance of fresh meat color, is examined in the light of 3‐dimensional structure of the molecule. The dynamic and reversible nature of color cycle involving constant oxygenation, oxidation, and reduction is emphasized. Oxygenation and oxidation are discussed on the basis of thermodynamic principles. The factors affecting fresh meat color are examined. The enzymic and nonenzymic metmyoglobin reducing systems are discussed in relation to fresh meat color. A full discussion on the inter‐relationship between lipid and pigment oxidation is presented. Recent developments on the methodology of color measurement are traced, pointing out the advantages and limitations of various methods.

カツオの肉色に関する研究

Attempts were made to clarify the cause of the characteristic dark red color of fresh skipjack meat, and to obtain data elucidating the empirical fact that skipjack meat is discolored much faster than other tuna fish meats during storage. The results are summarized as follows: 1) The presence of fairly large amounts of hemoglobin, mostly in the deoxy form due to the Root effect, was found to be responsible for the characteristic color of skipjack meat. 2) Both at 2-4°C and at about -20°C, the discoloration velocity of skipjack meat during storage was much faster than that of bigeye tuna. Unlike the meats of other tuna fishes, skipjack meats derived from superficial and inner parts and stored at about -20°C showed almost the same velocity of discoloration regardless of source. It was suggested that these features of stored skipjack meat may be attributed to such factors as the lower pH of the meat and the greater ease with which the enzymic system capable of reducing metmyoglobin loses its activity after fish death.