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1.
Meat Sci ; 79(1): 86-97, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-22062601

RESUMEN

The objective was to determine the effect of pre-slaughter growth rate on feed efficiency, components of body growth and on the tenderness of longissimus muscle from steers reared to a common age and carcass weight. Sixty Friesian steers were group-housed and offered grass silage ad libitum and 3.5kg concentrates per animal daily for 5 months and then 5kg concentrates and 1kg grass hay for 1month before the experiment began. The animals were then weighed and in a randomised block were assigned to one of 5 groups, for slaughter at the beginning of the experiment or to be offered concentrates and hay (900 and 100g/kg total diet, respectively) to achieve target growths of: 0.72kg/day continuously for 17 weeks, 0.36kg/day for the first 8 weeks and 1.08kg/day for the final 8 weeks (low-high), 1.08kg/day for the first 8 weeks and 0.36 for the final 8 weeks (high-low) or 0.36kg/day for the first 2 weeks, 0.72kg/day during weeks 4 and 14 and 1.08kg/day for the final 2 weeks (pulse). One week was allowed for transition to the different dietary allowances within each energy supply pattern. The mean age at the beginning and end of the study was 18 and 22.5 months, respectively. After slaughter, the weight of the carcass and kidney+channel fat depot were recorded, the pistola hind quarter was dissected into fat, lean and bone and the tenderness of the m. longissimus thoracis et lumborum (LTM) muscle was measured instrumentally and using a trained taste panel after 2, 7 or 14 days ageing. The pattern of energy supply did not affect carcass weight, fat score or kidney+channel fat weight. The pistola hind quarter from animals offered the low-high energy pattern had a similar composition to the continuously-fed animals but contained more muscle than that from animals offered high-low or pulse energy patterns. After 14 days ageing, LTM from the continuously-fed animals was more tender than that from animals offered the other energy supply patterns but shear force did not differ between supply patterns. The data do not support the hypothesis that pre-slaughter growth rate increases tenderness but suggest that energy supply pattern can influence body composition of finishing cattle.

2.
Meat Sci ; 79(2): 355-64, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22062764

RESUMEN

Steers were offered grass silage ad libitum and 6.4 kg concentrates daily for 126 days or silage ad libitum for 35 days, followed by concentrates ad libitum (Experiment 1). Steers were offered grass silage ad libitum and 6 kg concentrates daily for 154 days, concentrates ad libitum or grass silage ad libitum for 112 days followed by concentrates ad libitum (Experiment 2). All treatments received the same total concentrate allowance. In Experiment 1, there was no difference in any measurement of meat quality. In Experiment 2, ad libitum concentrate feeding per se, decreased redness and increased shear force of muscle at 2 days post-mortem. Delaying concentrate feeding decreased fat yellowness, decreased shear force at 7 and 14 days post-mortem and increased muscle redness at 14 days post-mortem. Modifications of the beef production system examined had minor effects on beef quality which are unlikely to be of commercial significance.

3.
Meat Sci ; 75(4): 551-7, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22064018

RESUMEN

The objective of this study was to determine if there is an association between tenderness in bovine M. longisimus dorsi (LD) and polymorphisms in the bovine calpain I (exons 9 & 14), calpain II (regulatory subunit) or growth hormone (intron 3) genes. Genomic DNA was isolated from bovine LD (n=281) on which quality attributes (Warner Bratzler shear force (WBSF), sarcomere length and composition) were also characterised. DNA polymorphisms were analysed using polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis. Association analyses were performed between genotypes at the four polymorphic loci and day 14 WBSF values. It was found that the calpain 1 exon 9 genotypes had an association with WBSF such that animals with the GA genotype exhibited decreased WBSF and increased tenderness when compared to animals with the GG genotype (P<0.05). This observation concurs with that of earlier studies, suggesting that this polymorphism is a functional marker for beef tenderness.

4.
Meat Sci ; 73(1): 151-6, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-22062064

RESUMEN

The aim of this study was to monitor the effects of the alteration of the pre-rigor environment of the bovine LD muscle using controlled temperature regimes in order to gain an insight into the early post-mortem pH/temperature/time interactions which are important from the point of view of tenderness and to identify possible reasons for inconsistencies in beef tenderness. LD muscles (n=12) were hot-boned within 90min post-slaughter, cut into three pieces which were randomly placed in polyethylene bags and submerged in water baths pre-set at the following temperatures; 0, 5, 10, 15, 20 and 25°C for 8 h post-mortem then stored at 2°C for up to 14-days post-mortem. The rate of pH decline increased with increasing temperature. Muscles incubated at 0 and 5°C were cold shortened however not all of these muscles were tough as indicated by Warner Bratzler shear force values (WBSF). A pH range of 5.9-6.2 at 3 h post-mortem (pH(3)) produced consistently tender beef where cold-shortening was avoided. Cold shortened muscles showed the greatest variation in tenderness at 14 days post-mortem and underwent the greatest amount of tenderisation (ΔWBSF) and proteolysis between days 2 and 14 post-mortem. Proteolysis of cold shortened muscle may induce variation in tenderness in these muscles.

5.
Meat Sci ; 73(2): 196-203, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22062289

RESUMEN

The objective of this study was to determine the effects of hot-boning, low voltage electrical stimulation (ES) and chilling temperature on the tenderness of bovine M. longissimus dorsi (LD) and M. semimembranosus (SM) muscles. LD (n=32) and SM (n=32) muscles were subjected to different post-mortem treatments; hot-boning (before 90min post-mortem), cold-boning (at 48h post-mortem), low voltage ES and rapid or slow chilling. Hot-boned muscles which were not electrically stimulated (NES) had higher Warner Bratzler shear force (WBSF) values (P<0.001) and shorter sarcomeres (P<0.001) than cold-boned muscles. Hot-boned muscles subjected to ES had lower pH values (P<0.001) post-stimulation and up to 8h post-mortem than NES muscles. At both chilling temperatures WBSF values were lower in ES hot-boned LD and SM muscles at days 2, 7 and 14 post-mortem than NES muscles. Hot-boned muscles subjected to slow chilling had longer sarcomeres (P<0.001) than those subjected to fast chilling. In hot-boned SM muscles, ES resulted in longer sarcomere lengths (P<0.001). However, ES did not have a significant effect on the sarcomere length of LD muscles. As indicated by WBSF values all muscles tenderised during ageing, including muscles which were 'cold shortened'. Proteolysis was not the main reason for differences in WBSF values between ES and NES muscles as judged by qualitative sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). A combination of slow chilling and ES had a positive effect on hot-boned muscles with respect to WBSF values.

6.
Meat Sci ; 73(2): 204-8, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22062290

RESUMEN

The objective of this study was to evaluate the importance of proteolysis and sarcomere length in determining the tenderness of bovine M. longissimus dorsi (LD) muscle over a 21-day period. This was done by altering the pre-rigor glycolytic behaviour of hot-boned LD muscles using different early post-mortem temperature regimes. Hot-boned LD muscles (n=8) were cut in two, randomised, placed in polythene bags and submerged in a water bath set at 5°C (rapidly chilled) and 15°C (slowly chilled) for 8h post-mortem. All muscles were then stored at 2°C for up to 21 days post-mortem. The temperature regimes altered the glycolytic behaviour of the muscles in the pre-rigor period. The slowly chilled muscles exhibited a faster (P<0.01) pH fall than rapidly chilled muscles. Cold shortening was induced in rapidly chilled muscles as they had shorter (P<0.01) sarcomere lengths than slowly chilled muscles up to day 21 post-mortem. Warner Bratzler shear force values (WBSF) deemed cold-shortened muscles as tougher than noncold shortened up to day 14 post-mortem. Both cold-shortened and noncold-shortened muscles tenderised over time to an extent where there was no significant difference in WBSF values by day 21 post-mortem. SDS-PAGE protein profiles indicated that the rate of proteolysis was faster in slowly chilled muscles when compared to rapidly chilled muscles. However by day 21 post-mortem it appeared that rapidly and slowly chilled muscles underwent proteolysis to the same extent.

7.
Meat Sci ; 72(3): 380-6, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22061721

RESUMEN

Pork loins were pumped to 110% of original weight with solutions containing 5.5% salt and 3.3% sodium tripolyphosphate, 5.5% salt and 3.3% ß-lactoglobulin (ß-lg) enriched fraction or 5.5% salt and 3.3% whey protein concentrate 80% (WPC80) for comparison with non-enhanced control loins. The enhancement of pork loins significantly increased (p<0.001) the tenderness and juiciness. Warner-Bratzler shear force values were lower (p<0.001) in enhanced then in non-enhanced control chops. The enhanced pork chops had a slightly higher overall flavour and overall acceptability to the control pork chops. Sensory analysis showed that ß-lg enriched fraction and WPC80 can be used as replacement ingredients to reduce the amount of phosphate used in enhancement solutions, as they were comparable to salt/sodium tripolyphosphate (salt/STPP) enhancement solution. Consumers rated the tenderness, juiciness and taste of the enhanced chops significantly (p<0.001) higher then the control chops.

8.
Meat Sci ; 73(1): 132-43, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-22062062

RESUMEN

The effect of supplementation of beef cattle diets with tea catechins (TC) (1000mg/animal/day) and rosemary extract (RE) (1000mg/animal/day), for 103 days preceding slaughter, on the oxidative stability of M. longissimus dorsi (LD) steaks was evaluated. Dietary supplementation with TC and RE did not increase plasma total antioxidant status (TAS), LD α-tocopherol concentrations or pH. In LD steaks stored aerobically or in modified atmosphere packs (80% O(2):20% CO(2)) (MAP) for up to 8 days at 4°C, surface redness (CIE 'a' redness value) and lipid stability (TBARS, mg MDA (malondialdehyde)/kg muscle) were not significantly improved as a result of supplementation with TC and RE. Similarly no improvement in the sensory properties and lipid stability of cooked LD slices, stored aerobically or in 30% CO(2):70% N(2) for up to 11 days at 4°C, was observed. An in vitro fermentation study demonstrated that TC and RE were not fermented to any great extent under simulated rumen conditions. Direct addition of TC (1000ppm) and RE (1000ppm) significantly (P<0.05) improved the colour and lipid stability in LD patties stored in 80% O(2):20% CO(2) for up to 8 days at 4°C, thus, demonstrating the antioxidant potential of TC and RE supplements employed in the present study.

9.
Meat Sci ; 71(2): 238-43, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22064221

RESUMEN

Four Beta-lactoglobulin (ß-lg) enriched fractions containing different mineral contents were prepared and evaluated in frankfurters. Frankfurters were assessed for cook loss, water holding capacity (WHC), textural and sensory characteristics. The addition of the ß-lg fractions reduced the cook loss (p<0.001) in comparison to the control (6.63% vs 3.98%). The fractions (ß-lg 1 and 2) with the lowest calcium level significantly reduced WHC (p<0.01). The ß-lg fractions had no detrimental effect on the sensory characteristics (p>0.05). All of the fractions increased the TPA value of hardness in comparison to the control (p<0.001) while the springiness decreased in the fractions (p<0.001) with the lowest mineral level. This study showed that the mineral composition of the ß-lactoglobulin fractions affected cook loss, tenderness and hardness (TPA) of the frankfurters and the addition of the ß-lactoglobulin enriched fraction did not affect the organoleptic quality of frankfurters in comparison to the control. This study shows the potential for next generation whey protein fractions and their application in meat products.

10.
J Agric Food Chem ; 48(8): 3476-84, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10956136

RESUMEN

The effect of fat content and carbohydrate fat-replacers on the release of volatile odor compounds from beefburger, salami, and frankfurter has been investigated. The reduction in fat content in any of the three meat products studied resulted in a tendency toward an increase in the quantities of volatiles released in the headspace. Tapioca starch and maltodextrin appear to delay the release of certain classes of compounds selectively; for instance, tapioca starch appears to slow the release of some Maillard products while maltodextrin has a similar effect on terpenes. In contrast, oat fiber decreases the release of most of the compounds analyzed. Thus, the addition of carbohydrate fat-replacers to low-fat meat products could assist the flavor qualities of low-fat meat products by slowing down the release of odor compounds.


Asunto(s)
Grasas de la Dieta , Productos de la Carne/análisis , Odorantes , Volatilización
11.
J Anim Sci ; 82(8): 2384-91, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15318738

RESUMEN

The objective of this study was to determine the effect of type of conserved forage and concentrate composition on the quality of beef held in overwrapped (aerobic) or modified atmosphere packaging under simulated retail display for 17 d. Friesian steers (n = 45) were assigned randomly to one of five dietary treatments: 1) extensively fermented grass silage plus silage concentrate (EFS); 2) restricted fermented grass silage plus silage concentrate (RFS); 3) starch-based concentrate plus wheat straw (SC); 4) nonstarch-based concentrate plus wheat straw (NSC); or 5) zero-grazed perennial ryegrass plus grass concentrate (RYE). Meat quality was determined by measuring color, lipid oxidation (TBARS), alpha-tocopherol concentrations, and fatty acid composition. In aerobically packaged beef, there was a display x diet interactive effect (P < 0.001) on Hunter a* values, with steaks from the EFS group having higher (P < 0.05) a* values than all other dietary groups from d 6 through d 17. Moreover, during the last 12 d of display, beef from the EFS group had the lowest (P < 0.01) proportion of metmyoglobin (display day x diet; P < 0.001). Under aerobic packaging, the SC and NSC groups produced steaks with higher (P < 0.05) TBARS values than RFS, EFS, and RYE groups, which did not differ from each other (display day x diet; P < 0.01). The SC and NSC groups had higher (P < 0.05) oxidation levels than RFS, EFS, and RYE groups, which did not differ from each other. Beef from the EFS group had (P < 0.05) higher concentrations of alpha-tocopherol than from the SC, NSC, and RYE groups. Beef from EFS-fed steers had a higher (P < 0.05) proportion of saturated fatty acids than the SC and NSC groups. It was concluded that the method of grass conservation influenced beef color, whereas concentrate composition did not. Color of aerobically packaged beef was improved by feeding animals silage that had undergone extensive fermentation. Conversely, oxidative stability was decreased by feeding animals starch- and nonstarch-based concentrate diets.


Asunto(s)
Alimentación Animal , Bovinos/metabolismo , Embalaje de Alimentos/métodos , Carne/normas , Oxígeno/metabolismo , Pigmentación , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Antioxidantes/análisis , Antioxidantes/metabolismo , Ácidos Grasos/análisis , Fermentación , Masculino , Metamioglobina/metabolismo , Poaceae , Distribución Aleatoria , Ensilaje , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Factores de Tiempo , Triticum , alfa-Tocoferol/análisis
12.
J Anim Sci ; 80(6): 1556-63, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12078737

RESUMEN

The effects of three preslaughter diets on heifer beef quality were investigated. Heifers (n = 45) were divided into three groups and fed for ad libitum consumption either maize silage, grass silage, or a 50:50 mixture of maize silage and grass silage. Meat quality was determined by measuring color, lipid oxidation, alpha-tocopherol levels, and fatty acid composition. Beef from the maize silage group had poorest color stability (P < 0.05), whereas beef from the grass silage diet had best (P < 0.05) color stability. The visual panel least preferred the maize silage group after 2 or more days of display, and lipid oxidation was significantly (P < 0.001) higher in this group compared to the 50:50 maize:grass silage and grass silage groups. There was a significant (P < 0.001) difference in the alpha-tocopherol levels detected in the meat from the three dietary groups. Alpha-tocopherol levels increased in the order: maize silage < 50:50 maize:grass silage < grass silage, at levels of 2.08, 2.95, and 3.84 microg/g meat, respectively. Fatty acid analysis indicated 18:3 was significantly (P < 0.001) lower in the maize silage-fed group than in the maize:grass silage and grass silage groups. However, 18:3 was significantly (P < 0.001) higher in the grass silage group than in the other two groups. There were no significant differences in all other fatty acids among the three dietary groups. It was concluded that beef from grass silage-fed animals had better overall quality in terms of color, lipid oxidation, and alpha-tocopherol levels than beef from maize silage fed animals.


Asunto(s)
Bovinos/metabolismo , Carne/normas , Poaceae , Ensilaje , Zea mays , Animales , Antioxidantes/análisis , Color/normas , Ácidos Grasos/análisis , Femenino , Metabolismo de los Lípidos , alfa-Tocoferol/análisis
13.
Meat Sci ; 48(1-2): 169-80, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22062889

RESUMEN

The effects of fat level (5% and 12%), tapioca starch and whey protein on the hydration/ binding properties, colour, textural and sensory characteristics of frankfurters were investigated. Decreasing the fat content increased cook loss and decreased emulsion stability and product lightness. Fat reduction increased smoke, spice and salt intensities and increased overall flavour intensity and juiciness. Texture profile analysis (TPA) indicated that fat reduction decreased gumminess and cohesiveness but the other parameters measured were unaffected. Addition of tapioca starch or whey protein reduced cook loss and increased emulsion stability. Whey protein did not effect the sensory characteristics but tapioca starch increased overall flavour intensity. Both ingredients increased hardness, adhesiveness, gumminess and chewiness as measured by TPA. Two-factor interactions between fat level and ingredient were observed for several parameters. The results indicate that both ingredients can partially offset some of the changes which occur in low-fat frankfurters when fat is replaced with added water and protein level is constant.

14.
Meat Sci ; 45(3): 273-81, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22061466

RESUMEN

The effects of fat level (5, 12 and 30%), carrageenan and oat fibre on the hydration/binding properties, colour and flavour characteristics of frankfurters were investigated. Decreasing the fat content from 30% to 5% significantly increased cook loss and decreased water holding capacity and emulsion stability. Reduced-fat products were also darker and redder compared with the 30% fat controls. Addition of carrageenan or oat fibre reduced cook loss and increased both water holding capacity and emulsion stability. Sensory evaluation indicated that decreasing fat from 30% to 5% increased the intensity of smokiness, spiciness and saltiness and reduced the overall acceptability of the flavour. Carrageenan or oat fibre did not alter the colour of the frankfurters and neither ingredient had a significant effect on the flavour characteristics assessed. The results demonstrate that carrageenan or oat fibre can partially offset some of the changes which occur in low-fat frankfurters when added water replaces fat and protein level is constant.

15.
Meat Sci ; 66(4): 765-70, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22061006

RESUMEN

Probes, which can be used on-line to rapidly and efficiently detect beef quality attributes (colour and tenderness), are currently being considered to predict ultimate beef quality. The contribution of the inherent sampling variability (due to factors such as muscle location) needs to be evaluated in order to optimise the sampling procedure for these measurements. The main objective of this trial was to monitor some sampling factors which may contribute to variation in pH and various quality attributes in bovine M. longissimus thoracis et lumborum (LTL). Location along the muscle did not impact on colour measurements (P⩾0.05). Location had no effect on cook loss, Warner Bratzler shear force (WBSF) and sarcomere length values (P⩾0.05). The moisture and intramuscular fat contents did vary (P⩾0.05); however, as the differences were very small this may not be of practical significance. Different models of pH meters/probes had a significant influence (P⩽0.01) on recorded pH values. However pH did not differ significantly (P⩾0.05) along the length of the LTL. The type of meter used also had a significant impact on colour readings and 1 h 'blooming' time was observed as optimal for measuring colour on beef.

16.
Meat Sci ; 49(4): 399-409, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22060622

RESUMEN

Heifers (n = 70) were slaughtered and hung conventionally in an industrial meat plant. Near infrared (NIR) spectroscopy was studied for its ability to predict selected meat quality attributes, i.e. Warner-Bratzler shear force (WBSF), sensory tenderness, texture, flavour and acceptability. Freshly cut steaks (2.5 cm thick) were taken from the longissimus dorsi (LD) muscle at 1, 2, 7 and 14 days post mortem for NIR analysis. Other samples (also 2.5 cm thick) were taken at 2, 7 and 14 days post mortem, vacuum-packaged in plastic bags and stored at -20 °C for WBSF measurement and sensory analysis. Heifers were slaughtered in two groups; between slaughterings, replacement of the spectrophotometer lamp and lamp assembly was necessitated by a bulb failure. Using principal component regression (PCR), correlation coefficients of 0.82 and 0.73 were obtained for the prediction of WBSF in sample sets 1 and 2, respectively. On merging both sample sets, this value was lowered slightly (r = 0.61). Correlation coefficients obtained for the prediction of tenderness, texture, flavour and acceptability were 0.67, 0.53, 0.51 and 0.46 respectively (set 1); 0.72, 0.71, 0.45 and 0.67 (set 2); 0.53, 0.54, 0.24 and 0.42 (combined sets).

17.
Meat Sci ; 45(2): 239-51, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22061306

RESUMEN

The rate of early post-mortem pH fall in bovine muscle was studied to determine its influence on the rate and extent of the tenderisation process. The pH of M. longissimus dorsi (LD) and M. semimembranosus (SM) muscles of Hereford cross Friesian heifers (n = 127) was taken up to 24 h post mortem. Twenty-four LD and 24 SM muscles were selected according to their rate of pH fall; slow (n = 8), intermediate (n = 8) and fast (n = 8) and were sampled at 2, 7 and 14 days post mortem for sensory, mechanical, physicochemical and biochemical analysis. Fast glycolysing LD muscles were rated more tender in sensory analysis and texture assessment whereas slow glycolysing muscles were considered significantly tougher (p < 0.001). Fast glycolysing LD had a significantly lower shear force (p < 0.001) at each stage of ageing. Slow glycolysing LD and SM had the highest shear force values. No significant difference was found in intramuscular fat or moisture content between the groups. Slow glycolysing LD muscles had shorter sarcomere lengths at 2 days post mortem. SDS-PAGE electrophoresis patterns showed increased proteolysis, such as the earlier appearance of the 30 kDa fragment, which is believed to be a good indicator of tenderness, in fast glycolysing muscle. These results suggest that the rate of post-mortem pH fall plays an important role in proteolysis and tenderisation.

18.
Meat Sci ; 55(1): 123-30, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-22060912

RESUMEN

The effects of salt level and high pressure processing on cook loss, emulsion stability, colour, textural and sensory characteristics of frankfurters were investigated. Two salt levels (1.5 and 2.5%) and two pressure treatments (150 and 300 MPa) were examined. For each batch a control was set up which was non-pressure treated. Cook loss values were significantly decreased in 150 MPa products at the 2.5% salt level compared to controls. Significantly lower cook losses were recorded at the lower salt level after the application of 150 MPa pressure. The stability of the meat emulsions was significantly increased at the lower salt level, especially after 150 MPa pressure. Sensory analysis results for overall flavour acceptability after pressure application of 150 MPa and 300 MPa were similar to control products and panellists preferred products formulated at 1.5% salt after pressure treatment (150 MPa). Hardness, cohesiveness, gumminess and chewiness were also improved after pressure treatment. The results demonstrate that high pressure technology is a viable process that partially compensates for the reduction of salt levels in frankfurters.

19.
Meat Sci ; 55(4): 463-9, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22061579

RESUMEN

The effects of fat level (5, 12 and 30%) and maltodextrin on emulsion stability, cook loss, colour, texture and sensory characteristics of frankfurters were investigated. Three fat levels (5, 12 and 30%) were formulated containing added maltodextrin. For each fat level a control was prepared without added maltodextrin giving a total of 6 treatments (3×2 factorial design). Reducing the fat from 30 to 5% increased cook loss and decreased emulsion stability. Panellists detected an increase in juiciness and a decrease in overall texture, overall acceptability when the fat level was reduced from 30 to 5%. Instron texture profile analysis showed a decrease in hardness, chewiness and gumminess and an increase in springiness with decreasing fat level. Maltodextrin addition caused a significant decrease in cook loss of the frankfurters but also decreased the emulsion stability. An interactive effect (P<0.05) occurred between fat level and maltodextrin resulting in no significant difference in hardness, gumminess and chewiness values when maltodextrin was present in the reduced-fat (5 and 12%) frankfurters. Saltiness, overall flavour intensity, overall texture and overall acceptability were unaltered (P>0.05) by maltodextrin. The results indicate that maltodextrin can be used as a suitable fat replacer since it offset some of the changes brought about by fat reduction, decreasing cook loss and maintaining a number of textural and sensory characteristics of the frankfurters.

20.
Meat Sci ; 54(1): 23-34, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22063708

RESUMEN

Heifers (n=47) were slaughtered and hung conventionally in an industrial meat plant. Electrical impedance (Py) and conductivity (EC) were studied for their ability to indicate or predict selected meat quality attributes i.e. Warner-Bratzler shear force (WBSF), sensory tenderness, texture, flavour and acceptability, water holding capacity (WHC) and colour. pH, electrical impedance (meat check) and electrical conductivity (pork quality meter) measurements were taken at hourly intervals up to 8 h and again at 1 and 2 days postmortem. Electrical measurements were taken again at 7 and 14 days postmortem. Freshly cut steaks (2.5 cm thick) were taken from the longissimus dorsi (LD) muscle at 2, 7 and 14 days postmortem, vacuum-packaged in plastic bags and stored at -20°C for WBSF and sensory analysis. Freshly cut steaks were used for WHC and colour measurements. During the development of rigor and over the ageing period, electrical changes occur in muscle tissue. Electrical measurements were found to change significantly between 1 and 14 days postmortem and when measured over the ageing period (at 2, 7 and 14 days postmortem) were significantly correlated to WBSF, sensory tenderness and Hunter 'a' and 'b' values (r=±0.56-±0.68, p<0.001) and weakly to moderately correlated to other sensory attributes (r=±0.31-0.58, p<0.001) measured at the same times postmortem; thus showing potential for these rapid physical measurements as indicators of meat quality if both electrical measurements and quality attributes are measured at the same times postmortem and correlations are calculated over the ageing period. However, electrical measurements taken at specific times at the early postmortem period (i.e. at 1 or 2 days) showed only a few weak relationships with meat quality attributes measured at later times postmortem (i.e. 7 or 14 days) demonstrating that early postmortem electrical measurements are not suitable for the prediction of ultimate meat quality. Py values taken between 7 h and 7 days postmortem were significantly correlated with all pH measurements with the exception of 1 day values. Two day Py measurements showed the highest correlations (r=0.45-0.62, p<0.01-0.001) with pH. EC was also found to be moderately correlated with pH although correlations were slightly lower than those obtained for Py. Highest correlations (r=0.47-0.59, p<0.01) were obtained for 7 h values.

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