A comparative study of boar taint in cooked and dry-cured meat

A comparative study of boar taint in cooked and dry-cured pig meat products was performed. Forty-eight cooked loins and 48 dry-cured hams from entire males and castrates were studied. The samples were classified according to the androstenone (AN) and skatole (SK) fat content determined using HPLC. A trained sensory panel evaluated taste, aroma, boar odour, boar flavour, juiciness, tenderness and fatness in cooked and dry-cured samples. Threshold levels of AN and SK to separate (P<0.05) entire and castrate samples according to their boar odour and flavour were determined. The effects of castration and processing on the eating quality were studied. Finally, the relationships among boar taint and other sensory attributes in cooked and dry-cured meat were compared. Results from these studies show that the eating quality of processed meat was affected negatively by boar taint. Threshold values were higher in dry-cured ham (2 μg g(-1) AN and 0.12 SK) than cooked loin (0.5 AN and 0.1 SK). AN and SK had a synergistic effect on boar odour and flavour in both products. AN had a greater influence than SK on the aroma and taste, especially in cooked meat. Boar odour was perceived more intensely than boar flavour in both of the products studied. Castration favoured fatness and improved the aroma and taste of cooked and dry-cured meat. The loss of aroma and taste due to boar taint was more noticeable in cooking than drying and curing. In dry-cured meat boar taint was associated with less aroma, taste, juiciness and tenderness. However, in cooked meat, boar taint affected the aroma and taste more strongly, but was not related with juiciness and tenderness, probably because these attributes are influenced by cooking.     

Effect of age and cut on cooking loss, juiciness and flavour of South African beef

The juiciness and flavour characteristics of 15 aged primal beef cuts of electrically stimulated carcasses, from three different age groups, were assessed (n=61). Cooking losses were determined and proximate analyses (moisture, fat, nitrogen and ash) were performed. Tender cuts were cooked by a dry heat method, and less tender cuts were cooked by moist heat methods. A trained panel (n=10) evaluated sensory quality characteristics including initial and sustained juiciness, aroma and flavour. Flavour intensity was the biggest discriminant between the three age groups and declined with an increase in age. Initial impression of juiciness decreased with increased age of the animal and cooking losses increased nonlinearly with age, irrespective of the muscle. In contrast sustained juiciness increased with increased age. Cuts cooked according to a dry heat cooking method were reported juicier (both initial and sustained) than those cooked by moist heat methods.     

Effect of dietary oil source on the flavour and the colour and lipid stability of lamb meat

This study investigated the influence of five sources of dietary oil (linseed oil (LO), fish oil (FO), a protected lipid supplement (PLS, 18:2 to 18:3 ratio 3:1), fish oil/marine algae (FOMA) and PLSMA) on the colour and lipid stability of lamb muscle and the flavour of grilled loin chops. LO produced the highest proportion of 18:3n−3 in muscle phospholipid, the highest ratings for lamb flavour intensity and overall liking and the lowest ratings for abnormal flavour intensity. PLS increased the proportion of 18:2n−6 which reduced lamb flavour intensity and increased abnormal lamb flavour intensity. Diets containing FO or MA increased proportions of the longer chain n−3 fatty acids and similar reduced ratings for lamb flavour as the PLS diet. FO-containing diets increased fishy flavour notes, especially when in combination with MA. ‘Putty’ and ‘fish oil’ odours were recognised as being present more frequently in cooked subcutaneous lamb fat from lambs fed FO and FOMA than other diets. Lambs fed MA, FO and the combination of the two produced meat that was oxidatively less stable and had a reduced colour and lipid oxidative shelf-life, which was at least partially due to the lower vitamin E content of the muscle.

These results have significant implications for the formulation of diets that may improve nutritional ratios in lamb meat but which adversely affect flavour and meat stability.     

Meat quality of Argentinean "Camperos" chicken enhanced in omega-3 and omega-9 fatty acids

Five diets were assessed with the aim of increasing oleic fatty acid and omega-3 polyunsaturated fatty acid content in 'campero' poultry meat and evaluating their influence on sensory attributes. Animals from treatment 1 (T1) were confined and fed with corn/soybean diet; in T2, animals were fed with a corn/soybean mix with free access to pasture; T3 diet had high oleic sunflower seeds (HOSS) and linseeds with access to pasture; T4 diet was similar to T2 with free access to chicory instead of pasture and T5 diet was similar to T3 with free access to chicory instead of pasture. Linseeds and HOSS supplementation significantly increased the fatty acids profile, regardless of forage supply. T3 MUFA content was significantly higher than in the other treatments. Due to the high presence of omega-3 PUFA in linseeds and HOSS treatments (T3 and T5), meat omega-6/omega-3 ratio decreased from 9 to 4. The presence of off-flavours was not influenced by diets but there was an interaction between portion and storage conditions. 'Poultry meat' aroma was only influenced by the storage conditions, being slight after 4 months of freezing, while presence of off-aromas was affected by diets. We conclude that it is possible to produce 'campero' poultry meat with enhanced omega-3 and omega-9 content and a low omega-6/omega-3 ratio using diets based on linseed and HOSS, without any important change in sensory properties.     

Comparison of the color stability and lipid oxidative stability of fresh and vacuum packaged lamb muscle containing elevated omega-3 and omega-6 fatty acid levels from dietary manipulation

A series of three experiments were conducted with second cross ([Merino×Border Leicester]×Poll Dorset) wether lambs to evaluate the effects of dietary treatments on manipulation of muscle long-chain (LC) omega-3 fatty acids (FA) on the color stability and oxidative stability of fresh and vacuum packaged lamb. At the end of 7-, 6- and 6-week experimental periods for experiments (Exp.) 1-3 respectively, lambs were slaughtered at a commercial abattoir. At 24 h post-mortem, muscle longissimus lumborum (LL) and longissimus thoracis (LT) were removed and evaluated for color and lipid oxidative stability under specified commercial storage and display condition. Of the dietary supplements used, fish meal and fish oil moderately (P<0.01) and markedly (P<0.001) increased muscle omega-3 FA content, while both protected canola seed (P<0.001) and protected sunflower meal protein significantly (P<0.02) increased muscle omega-6 FA content or ratio of omega-6/omega-3 of the longissimus muscle. In all experiments, the substantial increase (P<0.001) in muscle LC omega-3 and omega-6 FA had no consistent significant effect on color values (redness (a*), yellowness (b*) and lightness (L*)) for fresh and vacuum packaged lamb over a 6-day display period. Lipid oxidation, determined by the levels of thiobarbituric acid reactive substances (TBARS) indicated the enrichment of muscle polyunsaturated fatty acid (PUFA) levels in lambs did not produce significant differences resulting either from main treatment effects or for treatment×day×type interactions (where type was fresh and vacuum packaged). Present results demonstrated the color and lipid oxidative stability of lamb longissimus muscle during refrigerated display was not affected by enhanced levels of omega-3 and omega-6 FA due to dietary treatments.     

Use of generalized Procrustes analysis (GPA) to test the effects of sex and carcass weight on sensory quality evaluations of Terrincho lamb meat

Generalized Procrustes analysis (GPA) was used to test the sensory attributes of Terrincho lamb meat, a product with Protected Designation of Origin (PDO) labelling. Effects of sex and carcass weight on the following sensory attributes: toughness, juiciness, flavour intensity, odour intensity, stringiness, and level of sweetness were tested. Tests were performed on 28 females and 29 males placed within three classes of carcass weight, 3 to 9 kg. Meat sensory quality was evaluated, within five sessions, by a trained taste panel. Meat was cooked in a conventional oven, cut into pieces, and delivered to the panel for evaluation. Data were analyzed using a GPA to minimize differences between assessors. Two factors explained 72.76% of the total variability. The panel did not clearly detect sex effects, yet could differentiate meat by carcass weight as heavier animals were toughest and had more intense odour and flavour, whilst light animals were most succulent.     

Effects of goat milk or milk replacer diet on meat quality and fat composition of suckling goat kids

The effects of a diet with goat milk "GM" or milk replacer "MR" on the meat quality and fat composition of suckling Murciano-Granadina kids were studied. MR consisted of powdered skimmed milk, coconut oil and fat, and cereal products and by-products. Raw meat quality (moisture, protein, lipids, ash, collagen, cholesterol, haem pigments, CIELab colour, pH and water retention capacity), fatty acid "FA" composition and eating quality of cooked meat (odour, flavour and texture) were determined. Diet had only a slight effect on raw meat quality but had a pronounced effect on fatty acid composition and eating quality of cooked meat. MR diet increased the water/protein proportion in the muscle. The saturated/unsaturated FA ratio in GM and MR fat was 0.94 and 2.27, respectively. The major FA in GM and MR fat were C16:0 and C18:1, respectively. Short-chain C4-C12 hardly accumulated in the adipose tissue of suckling kid, increasing the relative percentages of C14-C20. This effect was more pronounced in MR fat, due to the fact that MR contained more short-chain fatty acids than GM. MR diet gave cooked meat a more intense characteristic goat meat odour and flavour, more tenderness and more juiciness than the natural suckling diet. This fact could be related to differences in meat and fat composition.     

Effects of USDA feeder grade and time-on-feed on carcass characteristics and cooked beef palatability

Yearling feeder steers (n = 128), selected to vary in frame size and muscle thickness, were fed for 100, 130 or 160 days and then slaughtered. USDA grade data were collected and cooked rib steaks were evaluated for palatability attributes. Frame size was positively related to carcass weight and longissimus muscle area and negatively related to all fatness measures and to USDA yield grade. Steaks from large-framed steers received the lowest sensory panel ratings for juiciness and overall palatability. Muscle thickness of feeder steers was positively related to all measures of carcass muscling. Steaks from thinly muscled (No. 3) steers received higher ratings for juiciness and overall palatability than did steaks from thickly muscled (No. 1) steers. Large-framed or thickly muscled (No. 1) steers produced the lowest percentages of carcasses with at least Choice quality. Although some statistically significant differences were observed when the data were sorted by frame size or muscle thickness, few real trends were evident that would be of value to cattle feeders.     

Elucidation of the relationship between cooking temperature, water distribution and sensory attributes of pork - a combined NMR and sensory study

Low-field NMR T(2) relaxation was measured continuously during cooking of pork samples (m. longissimus dorsi) to a final temperature of 75 °C. Simultaneously the remaining muscle was cooked in an oven to a core temperature of either 62 or 75 °C and subsequently evaluated by a sensory panel. Highly significant effects of final cooking temperature on the sensory attributes juiciness (initial and final), hardness, tenderness, crumbliness and chewing time were found. Juiciness and tenderness decreased with increasing temperature, while hardness, crumbliness and chewing time increased with increasing temperature. Distributed T(2) relaxation data revealed marked effects of temperature (62 vs. 75 °C) on the water distribution within the meat. Partial least squares (PLS) regressions were used to examine a potential prediction of sensory attributes from the distributed T(2) relaxation data, and high correlations were obtained. Moreover, loadings from the PLS regressions were analysed to evaluate the alterations in the water distribution as a function of temperature that contribute to changes in juiciness. This analysis revealed that the reduction in juiciness at 75 °C can be ascribed to changes in the size of the pores confining the myofibrillar water together with an expulsion of water.     

Changes in physical and sensory characteristics of marinated broiler drumsticks, treated with nisin and lactoperoxidase system

The lactoperoxidase system (LPS) and nisin have been shown to inactivate some micro‐organisms in foods. However, further studies were needed to evaluate whether these treatments had any influence on the physical and sensory characteristics of broiler drumsticks. In this study, a solution that contained 1% acetic acid and 3% salt with pH adjusted to 4 was developed as a standard marinade. The LPS consisted of 1‐μg mL^?1 lactoperoxidase, 5.9‐mm potassium thiocyanate (KSCN), and 2.5‐mm H₂O₂ was added to the marinade, followed by nisin at 100 IU mL^?1. The results showed that the physical characteristics, including raw and cooked drumstick pH, percentage incorporation of marinade solution, cooking loss, skin and muscle L*, a*, b* values, and sensory characteristics, including skin and muscle sensory colour, aroma and flavour, off aroma, off flavour, juiciness and tenderness of the broiler drumsticks, treated with 100‐IU mL^?1 nisin and LPS were not impaired.     

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.     

Sensory and functional meat quality characteristics of pork derived from three halothane genotypes

The effect of the halothane gene in pigs on the meat and sensory qualities thereof were determined. Meat derived from 60 Landrace×Large White pigs of three halothane genotypes was used. The sensory qualities, cooking loss, colour, shear value and proximate analysis of the cooked pork loin roasts were determined. The three genotypes did not differ significantly (P>0.05) with regard to the colour of the cooked meat, percentage cooking loss and percentage moisture. There were significant differences (P<0.05) between the genotypes in the percentage protein, ash and fat. Meat from the three genotypes also differed significantly (P<0.05) in juiciness, an analytical sensory panel scored the juiciness of meat from the NN-genotype the highest with a value of 71.3 when using a structured line scale. Meat from the nn-genotype had the lowest score for juiciness (62.8). Meat from the three genotypes did not differ significantly (P>0.05) with regard to tenderness, pork flavour and no mealiness. Correlation values showed a positive correlation (r=0.46, P<0.05) between juiciness and tenderness. These results indicate that the inclusion of the halothane gene in pig production programmes results in meat with an inferior quality and it can be recommended to exclude the halothane positive genotype from any pig production system where fresh pork quality is considered a primary goal.     

The effect of muscle, cooking method and final internal temperature on quality parameters of beef roast

The aim of the study was to evaluate the influence of cooking conditions (dry air and steam) and final internal temperature (75, 85, 95°C) on the physico-chemical properties of beef infraspinatus (INF) and semimembranosus (SEM) muscles as well as their tenderness and juiciness. Cooking method and temperature influenced moisture, total collagen content in cooked meat and cooking loss, whereas muscle type affected fat, total collagen content and cooking loss. Warner-Bratzler shear force values were affected by cooking method, which also influenced juiciness of roasts. Temperature affected tenderness and juiciness, whereas muscle type influenced juiciness. The most desirable tenderness had INF heated in steam and dry air to 95°C. Processing SEM in dry air to 85 and 95°C lowered the juiciness of the roasts. There were significant correlations between physico-chemical, sensorial and image attributes, however high accuracy of prediction (r(2)>0.8) was achieved only for SEM muscle.     

Sensory and chemical analysis of cooked porcine meat patties in relation to warmed-over flavour and pre-slaughter stress

Two independent sensory profiles were carried out to evaluate warmed-over flavour (WOF) development in cooked, chill-stored and reheated pork patties. The patties were derived from the Musculus semimembranosus of animals subjected to different pre-slaughter stress treatments. All patties were stored in oxygen permeable bags at 4°C for 0, 1, 2, 3 and 5 days to facilitate WOF development. In addition, thiobarbituric acid reactive substances (TBARS), conjugated dienes, pH, water content, total lipids and the fatty acid compositions of phosphatidyl choline (PC), phosphatidyl ethanolamine (PE) and total lipids, were measured in the cooked meat patties. A data analytical strategy involving Analysis of Variance-Partial Least Squares Regression (ANOVA-PLSR), to determine relationships between the design variables (WOF and pre-slaughter stress) and the sensory-chemical data, and PLSR to elucidate predictive links between the sensory and chemical data was utilised. WOF was found to involve the development of lipid oxidation derived nuance off-flavour and odour notes, e.g. rancid-like flavour and linseed oil-like odour, in association with a concurrent decrease in cooked pork meat-like flavour. The reduction in "meatiness", over the initial days, 0-2 of WOF development was attributed to the degradation of both, unstable sulfur-containing amino acids in meat proteins and sulfur-containing "meaty" aroma compounds. Whereas, at the later days, 3-5 of WOF development the "meaty" loss was ascribed to perceptual masking by lipid oxidation products. TBARS and conjugated dienes were found to be significant (P<0.05) predictors of the sensory terms related to the lipid oxidation aspect of WOF. Whilst the polyunsaturated fatty acid (PUFAs) contents of PE, PC and the total lipids were found to decrease with WOF development, reflecting their loss in lipid oxidation reactions. The sensory variation related to pre-slaughter stress appeared to be distinct from WOF variation and was described by a sour to sweet taste continuum. However, interactions were noted that indicated increasing pre-slaughter stress resulted in a decreased sensory perception of WOF. Moreover, pH and water content were found to significantly (P<0.05) predict the sensory effects resulting from pre-slaughter stress.     

A comparison between two methods (Warner-Bratzler and texture profile analysis) for testing either raw meat or cooked meat

Two methods for assessing texture characteristics of meat (Warner-Bratzler (WB) - and texture profile analysis (TPA)), both performed either on raw or on cooked meat, were tested in 96 samples of m. longissimus dorsi muscle of eight heifers and eight bulls, aged 1, 3 or 6 days post-mortem. A sensory analysis was also performed on 96 samples. Sensory variates were predicted by instrumental variates as follows: hardness was better predicted by TPA than by WB; springiness was only predicted by WB; juiciness was only significantly predicted by TPA; greasiness was always poorly predicted, but the prediction was better with TPA, and the number of chewings was also better predicted with TPA. Results suggested the convenience of performing a TPA for assessing meat texture as, in cooked meat, only TPA furnished highly significant correlations for hardness, for juiciness and for the number of chewings. Although WB could predict hardness and springiness, only the equation for the prediction of the number of chewings was useful (r(2)=0.171, P<0.004). It seems that texture parameters, assessed by a TPA and performed on cooked meat, are the best predictors of sensory texture in bovine meat.     

Lipid and flavour quality of stored breast meat from broilers fed marine algae

In the current study, broilers were fed either 2·8 or 5·5% natural golden marine algae (MA) or 2·1% menhaden oil in an effort to produce an n-3 fatty acid (FA) enriched broiler breast product with acceptable flavour and lipid quality. Previously cooked or raw breast samples were stored at -23°C for 82 d and evaluated at intervals for flavour and TBA values. All treatments significantly increased breast n-3 FA content compared to samples from control-fed birds. The greatest n-3 FA deposition (212 mg kg⁻¹) was achieved by feeding 5·5% MA. All dietary n-3 FA significantly reduced flavour scores compared to samples from control-fed birds, although 2·8% MA samples were still considered acceptable by consumer panelists. Deterioration of flavour quality during storage of previously cooked samples was accelerated by all n-3 FA treatments except 2·8% MA. The rate of TBA production during storage of cooked breast meat was increased by n-3 FA, but this was curtailed by storing samples raw. These data indicate that 2·8% MA is useful for enhancing poultry tissue n-3 FA with minimal compromise in flavour or lipid quality, thus yielding a product that may serve as a substitute for fish in the diet. © 1988 Society of Chemical Industry     

Wine industry residues extracts as natural antioxidants in raw and cooked chicken meat during frozen storage

The effect of Isabel (IGE) and Niagara (NGE) grape seed and peel extracts on lipid oxidation, instrumental colour, pH and sensory properties of raw and cooked processed chicken meat stored at -18°C for nine months was evaluated. The pH of raw and cooked samples was not affected by the addition of grape extracts. IGE and NGE were effective in inhibiting the lipid oxidation of raw and cooked chicken meat, with results comparable to synthetic antioxidants. The extracts caused alterations in colour, as evidenced by the instrumental (darkening and lower intensity of red and yellow colour) and sensory results of cooked samples. In the sensory evaluation of odour and flavour, IGE produced satisfactory results, which did not differ from synthetic antioxidants. These findings suggest that the IGE and NGE are effective in retarding lipid oxidation of raw and cooked chicken meat during frozen storage.