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1.
Meat Sci ; 96(1): 187-94, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23906753

RESUMO

Rapeseed and sunflower oil were used to replace pork backfat in UK-style sausages by incorporating the oils as pre-formed emulsions. Replacing the pork backfat emulsion with rapeseed emulsion at total fat content of about 12%, reduced total saturated fatty acid (SFA) composition from 38% to 14% (4.5 to 1.8 g/100 g), increased monounsaturated fatty acid (MUFA) composition from 45% to 59% and increased polyunsaturated fatty acid (PUFA) composition from 15% to 25%. Partial replacement of pork backfat with rapeseed at a fat content of about 20% reduced SFA from 38% to 24% (7.2 to 4.8 g/100 g). There were no significant differences in eating quality and overall liking other than slight differences in the attributes 'firmness' and 'particle size'. Improvement in the fatty acid composition was achieved without adversely affecting colour shelf life or lipid oxidation. The study suggests that a substantial reduction in SFA can be achieved by incorporating 'healthy' oils in UK-style sausages without adversely affecting eating quality or shelf life.


Assuntos
Ácidos Graxos Monoinsaturados/análise , Ácidos Graxos Insaturados/análise , Produtos da Carne/análise , Óleos de Plantas/química , Adulto , Animais , Cor , Culinária , Emulsões/química , Ácidos Graxos/análise , Feminino , Conservação de Alimentos , Qualidade dos Alimentos , Humanos , Metabolismo dos Lipídeos , Pessoa de Meia-Idade , Óleo de Girassol , Suínos , Tiobarbitúricos/análise
2.
Br Poult Sci ; 53(1): 57-65, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22404805

RESUMO

1. Colour (L*, a*, b*), pH and weight changes during tumbling, overnight holding and cooking were measured in pale, soft and exudative (PSE, L* > 58); normal; and dark, firm and dry (DFD, L* < 52) broiler breast fillets (n = 180) subject to tumbling in a low salt (4%), phosphate-free marinade at three target addition levels: 0, 10 and 20%. 2. The mean L* values for PSE, normal and DFD fillets were 60·1, 56·0 and 51·7 respectively, with corresponding mean pH values of 5·73, 5·85 and 6·07. 3. There were no significant differences in marinade uptake during tumbling for the three groups of fillets. Losses during overnight holding were highest for the PSE fillets, but losses for all three colour groups were relatively small (<2%). 4. Cooking losses for fillets of normal colour were 19·7, 24·1 and 26·2% at 0, 10 and 20% addition levels respectively, with corresponding yields of 80·3, 82·8 and 84·8%. 5. PSE fillets had higher cooking losses and lower yields than normal fillets (and DFD fillets had lower cooking losses and higher yields than normal fillets) but the differences were small and not always significant (P < 0·05). 6. There was a strong negative correlation between pH and L* (r = -0·82) in the raw fillets, but weaker correlations of yield with L* (r = -0·53) and pH (r = 0·38) in the cooked fillets.


Assuntos
Culinária/métodos , Análise de Alimentos , Carne/normas , Fosfatos/química , Cloreto de Sódio/química , Animais , Galinhas , Concentração de Íons de Hidrogênio , Fatores de Tempo , Água
3.
Meat Sci ; 85(1): 40-6, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20374862

RESUMO

Thirty-six brands of pork sausage were purchased from a total of 10 retailers over a 4 months period and assessed for eating quality. The brands included 5 of the 10 most popular sausages in the UK, 4 basic, 14 standard, 10 premium and 8 healthy eating brands. The average price, meat content, fat content and salt content was 3.31 pounds/kg, 62%, 17% and 1.6%, respectively, but there were wide differences in price (1.08 pound/kg-5.23 pounds/kg), meat content (32-97%), fat content (2.1-29.1%) and salt content (0.5-2.5%). Sausages were assessed by a trained sensory panel using 100mm unstructured line scales and 14 descriptors (skin toughness, firmness, juiciness, pork flavour, fattiness, meatiness, particle size, cohesiveness, saltiness, sweet, acidic, bitter and metallic) including overall liking. The declared meat content was positively correlated with price, skin toughness, firmness, pork flavour, meatiness, particle size and perceived saltiness (r=0.5 or better). The declared fat content was positively correlated with fattiness and sweetness (r=0.42 or better) but not juiciness. There was no significant correlation between declared salt content and perceived saltiness. A principal component analysis showed that the first two principal components accounted for 51% of the variability in the data. Products could be separated into four quadrants according to their price, meat content, fat content and their associated eating quality attributes.


Assuntos
Gorduras na Dieta/análise , Preferências Alimentares , Produtos da Carne/normas , Carne/normas , Cloreto de Sódio na Dieta/análise , Paladar , Animais , Custos e Análise de Custo , Gorduras na Dieta/economia , Humanos , Carne/economia , Produtos da Carne/economia , Tamanho da Partícula , Análise de Componente Principal , Sensação , Cloreto de Sódio na Dieta/economia , Suínos , Reino Unido
4.
Meat Sci ; 78(3): 176-84, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22062268

RESUMO

Organic and conventional lamb loin chops, labelled as British lamb, were bought from three major UK supermarket chains (designated A, B and C) in the Bristol area on 10 occasions over a six week period. Samples (n=360) were from unknown production systems but representative of what is available to UK consumers. The nutritional quality of muscle was assessed in terms of its fatty acid composition and eating quality was assessed by a trained sensory panel. Lamb prices varied between £9 and £12.50 per kg, with a relatively modest price differential between organic and conventional lamb chops of £1.10, £1.88 and £1.16 £/kg for supermarkets A, B and C, respectively. On average, organic chops were 20g heavier than conventional chops. Chops were relatively lean, having just 14% of subcutaneous fat, approximately half that of a similar survey 10 years ago. Organic lamb had a better eating quality than conventional lamb in terms of juiciness (p<0.05), flavour (p<0.05) and overall liking (p<0.05) thus providing some evidence for the perception among consumers that organic products 'taste better'. Differences in juiciness were attributed to the higher intramuscular fat content of organic meat whilst differences in flavour were attributed to differences in fatty acid composition, in particular, the higher level of linolenic acid (18:3) and total n-3 PUFA in organic chops. Conventional chops had a higher percentage of linoleic acid (18:2). Chops from both productions systems had a favourable n-6:n-3 ratio. The most important difference between the three supermarkets was that lamb flavour was significantly lower in chops from supermarket A, probably due to differences in their 'display until' dates. Chops from supermarket A were also the cheapest.

5.
Meat Sci ; 78(4): 343-58, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22062452

RESUMO

This paper reviews the factors affecting the fatty acid composition of adipose tissue and muscle in pigs, sheep and cattle and shows that a major factor is the total amount of fat. The effects of fatty acid composition on meat quality are also reviewed. Pigs have high levels of polyunsaturated fatty acids (PUFA), including the long chain (C20-22) PUFA in adipose tissue and muscle. The full range of PUFA are also found in sheep adipose tissue and muscle whereas cattle 'conserve' long chain PUFA in muscle phospholipid. Linoleic acid (18:2n-6) is a major ingredient of feeds for all species. Its incorporation into adipose tissue and muscle in relation to the amount in the diet is greater than for other fatty acids. It is deposited in muscle phospholipid at a high level where it and its long chain products eg aracidonic acid (20:4n-6) compete well for insertion into phospholipid molecules. Its proportion in pig adipose tissue declines as fat deposition proceeds and is an index of fatness. The same inverse relationships are not seen in ruminant adipose tissue but in all species the proportion of 18:2n-6 declines in muscle as fat deposition increases. The main reason is that phospholipid, where 18:2n-6 is located, declines as a proportion of muscle lipid and the proportion of neutral lipid, with its higher content of saturated and monounsaturated fatty acids, increases. Oleic acid (18:1cis-9), formed from stearic acid (18:0) by the enzyme stearoyl Co-A desaturase, is a major component of neutral lipid and in ruminants the same enzyme forms conjugated linoleic acid (CLA), an important nutrient in human nutrition. Like 18:2n-6, α-linolenic acid (18:3n-3) is an essential fatty acid and is important to ruminants since it is the major fatty acid in grass. However it does not compete well for insertion into phospholipid compared with 18:2n-6 and its incorporation into adipose tissue and muscle is less efficient. Greater biohydrogenation of 18:3n-3 and a long rumen transit time for forage diets also limits the amount available for tissue uptake compared with 18:2n-6 from concentrate diets. A positive feature of grass feeding is that levels of the nutritionally important long chain n-3 PUFA are increased ie EPA (20:5n-3) and DHA (22:6n-3). Future research should focus on increasing n-3 PUFA proportions in lean carcasses and the use of biodiverse pastures and conservation processes which retain the benefits of fresh leafy grass offer opportunities to achieve this. The varying fatty acid compositions of adipose tissue and muscle have profound effects on meat quality. Fatty acid composition determines the firmness/oiliness of adipose tissue and the oxidative stability of muscle, which in turn affects flavour and muscle colour. Vitamin E is an essential nutrient, which stabilises PUFA and has a central role in meat quality, particularly in ruminants.

6.
Meat Sci ; 73(1): 166-77, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-22062066

RESUMO

Palm kernel oil (PKO) and palm oil (PO) are used in tropical countries as cheaper substitutes for conventional feed sources such as soya bean oil (SBO) but little is known about their effects on meat quality. This study, therefore, evaluated the effects of these three dietary oils on the fatty acid composition (FA) of pork fat and the qualities of belly bacon and frankfurter sausage. The 3×2 factorial design also included high and low dietary protein. Total cooking loss, water loss and fat losses were determined in frankfurter sausages at chopping temperatures from 2 to 24°C. PKO resulted in a poor P:S ratio (0.34) and a relatively hard fat (slip point 32.8°C), but resulted in bacon with a higher tensile cohesive force and more high quality slices, judged subjectively. PO had a fatty acid composition closer to the SBO control, a better P:S ratio than PKO (0.48) and softer fat. There was a trend for total cooking losses and fat losses to be higher in PKO compared with PO and SBO at all chopping temperatures, suggesting that the firmest, most saturated fat (PKO) was least suitable for frankfurter production. The low protein diet increased the concentration of saturated fatty acids and increased fat firmness but its effect on fatty acid composition and other properties were less marked than those of oil type.

7.
Meat Sci ; 73(1): 157-65, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-22062065

RESUMO

This study evaluated the effects of three dietary oils - palm kernel (PKO), palm (PO) and soyabean (SBO) - and two protein levels - high (HP) and low (LP) in a 3×2 factorial design involving 60 pigs on growth performance, muscle fatty acid composition and content, carcass, meat and eating qualities. Oil type did not have a significant effect on growth and carcass quality. PKO significantly reduced the polyunsaturated (PUFA) to saturated (SFA) fatty acid (P:S) ratio in longissimus muscle (P<0.001). PKO increased the concentrations of lauric (12:0), myristic (14:0), palmitic (16:0) and stearic (18:0) fatty acids and decreased linoleic acid (18:2). The LP diet increased intramuscular fat (IMF) from 1.7g/100g muscle in HP to 2.9g/100g (P<0.001), increased tenderness by 0.6 units (P<0.01) and juiciness by 0.5 units (P<0.01) on the 1-8 scale, but at the expense of lower daily weight gain (P<0.01), lower feed conversion efficiency (P<0.01), reduced P:S ratio (P<0.001) and increased lipid oxidation (P<0.01). The results suggest that PKO and PO could be used in tropical developing countries as cheaper alternatives to SBO for the production of good quality and healthy pork, but their limits of inclusion need to be determined.

8.
Meat Sci ; 70(4): 699-707, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22063897

RESUMO

The effects of breed and marination were tested for their effects on meat pH, water holding (marinade uptake and losses) and eating quality (tenderness, juiciness and flavour). Loins were removed from one side of 20 Large White-sired and 20 Hampshire-sired pigs after slaughter, cut into four pieces and injected to 112% of their initial weight with water, a polyphosphate-containing marinade (pH 7.7) or a high pH marinade (pH 10.3). An uninjected piece of loin served as control. Samples were left overnight and then frozen before being thawed, cooked and assessed by a trained ten member sensory panel using 1-8 category scales. Hampshires had higher intramuscular fat (0.95%) than Large Whites (0.62%) but otherwise the effects of breed were small compared with marination. Both marinades significantly increased meat pH from 5.5 (control) by 0.2U, significantly reduced the cooking loss and increased the meat yield from about 80% to 90%. Water-injected samples lost large amounts of added water as drip after thawing and had a yield (76%) similar to the control. Marinaded samples retained more water post-cooking. Both marinades significantly increased tenderness (p<0.001) and juiciness (p<0.001) by about 1.0U compared with the control (4.4 for tenderness and 4.2 for juiciness). Pork flavour, however, was significantly reduced (p<0.001) and abnormal flavour was significantly increased (p<0.001) by marination. Tenderness was positively correlated with pH after injection (0.83) and yield (0.75); juiciness was also positively correlated with pH after injection (0.78) and yield (0.87). The absence of any significant difference in eating quality between control and water-injected samples, and the relatively large effects of marination, suggest that retained water (after cooking) is crucial in determining perceived tenderness and juiciness in pork.

9.
Meat Sci ; 68(2): 305-11, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22062241

RESUMO

Several marinade solutions were tested for their effects on pork tenderness. Paired loins were removed from eight Large White crossbred pigs. Each pair was cut to give eight pieces and injected to a target of 110% of original weight with one of the following eight solutions (g/100 g water): uninjected (A, control), 5% salt (B), 5% sodium tripolyphosphate (C), 3% sodium bicarbonate (D), 5% salt and 5% sodium tripolyphosphate 5% (E), 5% salt and 3% sodium bicarbonate (F), 5% sodium tripolyphosphate and 3% sodium bicarbonate (G), 5% salt, 5% sodium tripolyphosphate and 3% sodium bicarbonate (H). Samples were left overnight to equilibrate, cooked and assessed for tenderness using a Volodkevich shear force method. Mean pHs for meat injected with phosphate and/or bicarbonate (C-H) ranged from 5.75 to 5.97, compared to 5.45 for the control. All injected loins, had a significantly higher yield than the control (p<0.05), except salt alone which, though higher, did not differ significantly (p>0.05) from the control. Treatment H increased the yield from 70% (control) to 85%. All marinades significantly reduced the shear force (p<0.05), some treatments (D and F) by up to a half compared to the control (5150 g). Individual animal results suggest that marination could be used to good effect even in the toughest samples, whilst improving tender samples still further. Samples treated with bicarbonate had an usual porous structure, probably due to carbon dioxide produced during cooking which may have contributed to the reduced toughness.

10.
Meat Sci ; 66(1): 21-32, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22063928

RESUMO

Interest in meat fatty acid composition stems mainly from the need to find ways to produce healthier meat, i.e. with a higher ratio of polyunsaturated (PUFA) to saturated fatty acids and a more favourable balance between n-6 and n-3 PUFA. In pigs, the drive has been to increase n-3 PUFA in meat and this can be achieved by feeding sources such as linseed in the diet. Only when concentrations of α-linolenic acid (18:3) approach 3% of neutral lipids or phospholipids are there any adverse effects on meat quality, defined in terms of shelf life (lipid and myoglobin oxidation) and flavour. Ruminant meats are a relatively good source of n-3 PUFA due to the presence of 18:3 in grass. Further increases can be achieved with animals fed grain-based diets by including whole linseed or linseed oil, especially if this is "protected" from rumen biohydrogenation. Long-chain (C20-C22) n-3 PUFA are synthesised from 18:3 in the animal although docosahexaenoic acid (DHA, 22:6) is not increased when diets are supplemented with 18:3. DHA can be increased by feeding sources such as fish oil although too-high levels cause adverse flavour and colour changes. Grass-fed beef and lamb have naturally high levels of 18:3 and long chain n-3 PUFA. These impact on flavour to produce a 'grass fed' taste in which other components of grass are also involved. Grazing also provides antioxidants including vitamin E which maintain PUFA levels in meat and prevent quality deterioration during processing and display. In pork, beef and lamb the melting point of lipid and the firmness/hardness of carcass fat is closely related to the concentration of stearic acid (18:0).

11.
Meat Sci ; 59(4): 423-35, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22062968

RESUMO

Bacon sometimes produces a white, unsightly fluid that exudes from the surfaces during cooking -a phenomenon that has resulted in frequent consumer complaints. The quantity of exudate from bacon of known history was assessed subjectively, by ranking photographs following 'dry-frying', and objectively, by collecting exudate in an ice cooled tray after grilling. Trained assessors ranked samples in order of visible exudate as follows: dry cured

12.
Meat Sci ; 55(2): 201-12, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22061086

RESUMO

Eighty pigs, male and female littermate pairs, were fed a control or a test diet from 25 to 95 kg live weight. The diets, as fed, contained 15.5 g/kg linoleic acid (18:2) and 1.9 g/kg α-linolenic acid (18:3) (control) or 10 g/kg linoleic acid and 4 g/kg α-linolenic acid (test). The test diet, with added linseed, was, therefore, high in the main n-3 polyunsaturated fatty acid (PUFA) 18:3 and low in the main n-6 PUFA 18:2. Making this relatively small change led to a 56% increase in the content of 18:3 in muscle and major increases in the contents of the beneficial longer chain PUFAs EPA (20:5n-3) (100% increase) and DHA (22:6n-3) (35% increase) which are synthesised from 18:3n-3. Levels of EPA and DHA in pigmeat adipose tissue were also increased by the test diet. In liver, the test diet resulted in an 18:3 level 4× higher than in muscle, with 10× more EPA and 20× more DHA. Sausages, analysed after 6 months frozen storage also had high n-3 PUFA levels, due to the contribution of these fatty acids from both muscle and adipose tissue. From a health perspective these results confirm the potential of pigmeat to supply valuable n-3 PUFA to the human diet. The test diet produced a PUFA:saturated FA ratio in muscle of 0.4, close to the minimum recommended value for the diet as a whole and an n-6:n-3 ratio of 5, a significant improvement on the current average for pigmeat (7). It is estimated that the test diet would provide 12 g of long chain n-3 PUFA to the human diet per annum at current pigmeat consumption levels in the UK, about a third of that from oily fish.

13.
Meat Sci ; 55(2): 213-21, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22061087

RESUMO

Pork chops, liver, bacon and sausages from 80 pigs fed on a control or a linseed-rich test diet were assessed for their sensory qualities and oxidative stability after conditioning and storage, either frozen or under simulated retail display. There was no significant effect of diet on lipid oxidation as assessed by the TBA test (P>0.05) for pork, liver and sausages, values being less than 0.2 throughout the display period, lower than the threshold of 0.5 mg MDA/kg at which consumers may detect rancidity. Nor was there any significant effect of diet on colour changes of pork chops, sausages and bacon under simulated retail display conditions. Grilled loin chops, bacon and sausages from male pigs received significantly higher abnormal flavour scores than those from females but panellists were unable to discern any major differences between control and test diets, even though they could detect this relatively small sex effect. The test diet resulted in higher α-linolenic acid (18:3) levels, with major increases in total n-3 PUFA content, but the concentrations were generally lower than reported values that have resulted in stability problems. The n-6 PUFA content was also reduced by the test diet. The results demonstrate that the nutritional value of pigmeat can be improved by using an 18:3-enriched diet without adversely affecting normal eating quality parameters.

14.
Meat Sci ; 56(2): 127-32, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22061899

RESUMO

Thirty-two female pigs were slaughtered and their left sides suspended conventionally by the Achilles tendon whilst right sides were suspended from the pelvic bone. The first 16 pigs were used to measure suspension effects on the characteristics of three major leg muscles (m. gluteobiceps, m. semimembranosus and m. rectus femoris) and to assess their suitability for ham manufacture. The remaining pigs were used for the production of hams, made from tunnel- boned whole legs injected to a target 10% weight gain, then tumbled and cooked. Compared with conventional hanging, pelvic suspension resulted in significantly (P<0.01) lower weight loss from the sides during chilling (2.8 and 2.5%). There were major changes in the shape of all three muscles, with pelvic suspension producing marked increases in the width of the m. gluteobiceps (24%) and length of the m. semimembranosus (34%), and a small reduction in the length of the m. rectus femoris (2%). It also resulted in the two former muscles having a relatively higher brine retention, lower drip losses after storage and lower instrumental texture values (Volodkevitch shear force). Cooking loss was reduced in the pelvic-suspended m. semimembranosus. Similarly, whole gammon hams made from pelvic-suspended sides had greater injection gains than hams from conventionally-hung sides (13.6 and 12.3%), with lower cooking losses (16.7 and 19.0%). Instrumental texture values (punch and die peak force) made on the individual muscles in 3-mm thick slices were lower for the m. gluteobiceps (5914 and 9085 g) and m. semimembranosus (6163 and 7600 g) as a result of pelvic suspension. There were minor but significant effects on some colour parameters which probably have little commercial impact. The results demonstrate the advantages of pelvic suspension in terms of brine uptake and retention, and hence increased yield, as well as reduced toughness, for at least two of the major leg muscles, m. gluteobiceps and m. semimembranosus, with no disadvantage for the m. rectus femoris. Together, these three muscles constitute about half of the trimmed leg weight.

15.
Proc Nutr Soc ; 58(2): 363-70, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10466178

RESUMO

Meat quality describes the attractiveness of meat to consumers. The present paper focuses on two major aspects of meat quality, tenderness and flavour. Both aspects of quality can be influenced by nutrition, principally through its effects on the amount and type of fat in meat. In several countries, high levels of intramuscular fat (marbling fat), i.e. above 30 g/kg muscle weight in longissimus, are deemed necessary for optimum tenderness, although poor relationships between fat content and tenderness have generally been found in European studies, where fat levels are often very low, e.g. below 10 g/kg in UK pigs. Muscle lipid may be a marker for red oxidative (type 1) muscle fibres which are found at higher concentrations in tender muscles and carcasses. Nutritional treatment can be used to manipulate the fatty acid content of muscle to improve nutritional balance, i.e. increase the polyunsaturated (PUFA): saturated fatty acid value and reduce the n-6:n-3 PUFA value. Increasing PUFA levels may also change flavour because of their greater susceptibility to oxidative breakdown and the generation of abnormal volatile compounds during cooking. This situation particularly applies to the n-3 PUFA which are the most unsaturated meat lipids. In pigs, a concentration of 3 mg alpha-linolenic acid (18:3)/100 mg in muscle and fat tissue fatty acids can easily be achieved by including whole linseed in the diet. This level has led to abnormal odours and flavours in some studies, but not in others. In cattle and sheep, feeding whole linseed raised 18:3 concentrations in muscle fatty acids from about 0.7 mg/100 mg to > 1 mg/100 mg. As with pigs, this diet also increased levels of long-chain n-3 PUFA formed from 18:3, including eicosapentaenoic acid (20:5). Although this increase led to greater oxidative breakdown of lipids during storage and the generation of large quantities of lipid-derived volatile compounds during cooking, there were no deleterious effects on odour or flavour. When 18:3 levels are raised in lamb and beef because of grass feeding, the intensity of the flavours increases in comparison with grain-fed animals which consume and deposit relatively more linoleic acid (18:2). In ruminants, very high levels of 18:2 produced by feeding protected oil supplements cause the cooked beef to be described as oily, bland or pork-like.


Assuntos
Carne/análise , Controle de Qualidade , Fenômenos Fisiológicos da Nutrição Animal , Animais , Gorduras na Dieta/administração & dosagem , Ácidos Graxos/análise , Ácidos Graxos Insaturados/administração & dosagem , Humanos , Lipídeos/análise , Valor Nutritivo , Ruminantes , Suínos , Paladar
16.
Meat Sci ; 51(4): 371-6, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22062033

RESUMO

Two injection levels (5 and 10%) and three concentrations of polyphosphate (0, 3 and 5%) were used in 64 pork loin portions to assess the influence of polyphosphate injection on eating quality of pork steaks cooked by grilling to a centre temperature of 72.5 or 80°C and assessed by a trained ten member sensory panel. Polyphosphate improved water holding, and generally produced more tender and more juicy meat than control steaks, although pork flavour intensity was reduced and abnormal flavour intensity increased. Raising the centre temperature from 72.5 to 80°C increased the cooking loss from 35 to 42%, reduced tenderness, juiciness and abnormal flavours and increased pork flavour intensity. Steaks containing 5% polyphosphate and cooked to 80°C were more tender and as juicy as steaks without polyphosphate cooked to the lower centre temperature. These effects were generally larger than those that can be achieved `naturally' by, for example, changing diets and breeds but whether the technology will be utilised in an increasingly `additive free' climate is debatable.

17.
Meat Sci ; 49(2): 175-91, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22063307

RESUMO

The chemical composition and energy content of four product categories (sausages, restructured steaks, burgers and minced beef) were determined before and after cooking. Two cooking methods were used for each product category: sausages and burgers were fried or grilled, restructured steaks were grilled or cooked in an oven whilst mince was either boiled or lightly fried and then boiled to simulate domestic practice. Based on an initial 100 g of product and excluding the low fat products included in the survey, the average weights after cooking were 78, 73, 72 and 70 g for the sausages, restructured steaks, burgers and minced beef, respectively; average fat contents before and after cooking were 22 and 17 g for the sausages, 17 and 14 g for the restructured steaks, 25 and 16 g for the beef burgers, and 19 and 7 g for the mince; and average energy contents before and after cooking were 1215 and 1016 kJ for the sausages, 958 and 815 kJ for the restructured steaks, 1244 and 906 kJ for the burgers and 1009 and 544 kJ for the mince. For a given product type, cooking method was relatively unimportant; the cooking loss, fat loss and energy content of the cooked product being more dependent on product formulation and manufacturing process. The survey included a low fat sausage, a low fat burger, a lean mince and an extra lean mince with fat contents of 8.7, 7.5, 12.4 and 5.2%, respectively. Overall weight losses during cooking were similar to standard products, though low fat products lost proportionally more water and less fat. Frying resulted in a slight gain in fat content for the low fat sausages and burgers, based on an initial 100 g of product, though fried low fat products still had lower fat and energy contents than standard products. It is argued that national consumption figures should take into account the losses that occur during cooking to avoid overestimating fat and energy intake levels.

18.
Meat Sci ; 49(2): 193-204, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22063308

RESUMO

The physical and chemical composition of pork loin chops was investigated, examining the changes that occurred in (i) the whole chop, (ii) the fat tissue and (iii) the lean tissue by grilling to 80 °C. Adjacent 25 mm thick chops, with backfat and rind attached, were cut from loins of 90 kg live weight pigs having a fat thickness (P(2)) of 11 mm, representative of current UK production. One chop was analysed fresh by dissection and standard analytical techniques and the other after grilling. Weights of chop (including rind) before and after cooking were 210 and 136 g, respectively. The average weight loss for the whole chop was 35%; the weight loss from fat, 44%, being greater than that from lean, 34%, or rind, 27%, the latter accounting for 14% of the whole raw chop. When expressed conventionally, on a percentage basis, the fat content of the whole rindless chop increased from 22 to 23%, and the fat content of the lean increased from 5.5 to 9%. In absolute terms, based on an initial 100 g, the fat content in the whole chop reduced from 22 to 15 g, with a slight increase in the fat content of the lean, from 5.5 to 6.0 g. It is argued that the National Food Survey (NFS) approach of estimating fat consumption on the basis of the fat content of the raw product is flawed. The terms 'meat consumption' and 'fat consumption' are misleading since they reflect amounts purchased rather than the amount of meat and fat actually consumed, making no allowance for fat lost during cooking or for subcutaneous fat removed by consumers before consumption. Actual fat consumption from cooked meat and meat products, after allowing for a 25% fat loss during cooking and trimming of visible fat, is estimated at 10.3 g per person per day compared with the NFS estimate of 18.1 g.

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