In Australia, the term ‘red meat’ is used by the meat industry to refer to meat from cattle, sheep and goat (i.e. beef, veal, lamb, mutton and goat meat). It does not include meat from pigs (e.g. pork, bacon, ham) or kangaroo, nor less common game meats like buffalo and camel, although nutrient composition of some of these products is now becoming available. 2 Purchased red meat usually consists of both lean tissue (muscle) and fat tissue, which can be either distributed throughout the muscle as marbling (internal fat) or surrounding the muscle meat as selvage or external fat. In trimmed lean meat, it is usually the external fat only that is removed. 3 Processed meat means a product containing no less than 30% meat, that has undergone a method of preservation other than freezing, and includes manufactured meat and cured and/or dried meat flesh (e.g. sausages, salami, canned meats). 1 This paper outlines the key nutrients for which red meat could be considered a significant dietary source based on data of relative composition.

The term ‘meat’ may refer only to meat flesh (skeletal muscle plus any attached connective tissue or fat), but the FSANZ definition also includes offal (i.e. meat other than meat flesh, including brain, heart, kidney, liver, pancreas, spleen, thymus, tongue and tripe) although it excludes bone and bone marrow.

The Food Standards Australia New Zealand (FSANZ) Food Standards Code defines meat as ‘the whole or part of the carcass of any buffalo, camel, cattle, deer, goat, hare, pig, poultry, rabbit or sheep, slaughtered other than in a wild state, but does not include eggs, or foetuses’. 1 This definition does not include kangaroo meat, which is now widely available for purchase in Australia and is likely to be considered as meat.

NUTRIENT COMPOSITION OF RED MEAT

Red meat contains high biological value protein and important micronutrients that are needed for good health throughout life. It also contains a range of fats, including essential omega‐3 polyunsaturated fats. Recent analyses have shown that there has been a significant trend to leaner cuts of meat over the past two decades.4 While the nutritional composition will vary somewhat according to breed, feeding regimen, season and meat cut, the following discussion will show that, in general, lean red meat has a relatively low fat content, is moderate in cholesterol, and is rich in protein and many essential vitamins and minerals.

Table 1 presents the typical nutrient composition of samples of fat‐trimmed Australian red meat (beef, veal, lamb and mutton), based on recent analyses of national retail samples,5-7 and compares this with the new Australian recommended dietary intakes (RDI).8 While there are some differences between the four meats, in general lean red meat is a particularly good source of protein, niacin, vitamin B6, vitamin B12, phosphorus, zinc and iron, with 100 gproviding more than 25% RDI of these nutrients. It also provides more than 10% RDI of riboflavin, pantothenic acid and selenium. Of the four meats, mutton is particularly nutrient‐dense, and the richest source of thiamin, vitamins B6 and B12, phosphorus, iron and copper.

Table 1. Average nutrient composition (per 100 g) of the lean component of Australian red meat Beef (a) Veal (b) Lamb (c) Mutton (d) Adult Australian RDI Moisture (g) 73.1 74.8 72.9 73.2 Protein (g) 23.2 24.8 21.9 21.5 46–64 Fat (g) 2.8 1.5 4.7 4.0 – Energy (kJ) 498 477 546 514 6.5–15.8 MJ Cholesterol (mg) 50 51 66 66 – Thiamin (mg) 0.04 0.06 0.12 0.16 1.1–1.2 Riboflavin (mg) 0.18 0.20 0.23 0.25 1.1–1.6 Niacin (mg) 5.0 16.0 5.2 8.0 14–16 Vitamin B6 (mg) 0.52 0.8 0.10 0.8 1.3–1.7 Vitamin B12 (μg) 2.5 1.6 0.96 2.8 2.4 Pantothenic acid (mg) 0.35 1.50 0.74 1.33 4–6 Vitamin A (μg) <5 <5 8.6 7.8 700–900 μg RE(e) Beta‐carotene (μg) 10 <5 <5 <5 700–900 μg RE(e) Alpha‐tocopherol (mg) 0.63 0.50 0.44 0.20 7–10 Sodium (mg) 51 51 69 71 460–920 Potassium (mg) 363 362 344 365 2800–3800 Calcium (mg) 4.5 6.5 7.2 6.6 1000–1300 Iron (mg) 1.8 1.1 2.0 3.3 8–18 Zinc (mg) 4.6 4.2 4.5 3.9 8–14 Magnesium (mg) 25 26 28 28 310–420 Phosphorus (mg) 215 260 194 290 1000 Copper (mg) 0.12 0.08 0.12 0.22 1.2–1.7 Selenium (μg) 17 <10 14 <10 60–70

Protein and amino acids Raw red muscle meat contains around 20–25 g protein/100 g. Cooked red meat contains 28–36 g/100 g, because the water content decreases and nutrients become more concentrated during cooking. The protein is highly digestible, around 94% compared with the digestibility of 78% in beans and 86% in whole wheat.9 Protein from meat provides all essential amino acids (lysine, threonine, methionine, phenylalanine, tryptophan, leucine, isoleucine, valine) and has no limiting amino acids. Protein Digestibility Corrected Amino Acid Score is a method of evaluating the protein quality, with a maximum possible score of 1.0. Animal meats like beef have a score of approximately 0.9, compared with values of 0.5–0.7 for most plant foods.10 The amino acid glutamic acid/glutamine is present in meat in the highest amounts (16.5%), followed by arginine, alanine and aspartic acid.

Fat Table 2 shows examples of the amount of separable fat found on typical retail cuts of red meat available for sale in Australia.4, 11 There is a wide variation in the amount of total separable fat between the different beef and lamb cuts, ranging from 37% in loin lamb chops to only 1% in veal steak. Table 2. Lean and separable fat from untrimmed raw boneless Australian red meat (mean weight) Meat cut % Lean % External fat % Internal fat Beef Topside roast 91 6 3 Silverside roast 89 7 4 Blade steak 88 6 6 Porterhouse steak 77 18 5 Stir‐fry 98 2 0 Scotch fillet 81 8 11 Veal Leg steak 99 0 1 Diced 98 2 0 Cutlet 93 1 6 Lamb Leg roast 83 11 6 Chump chop 75 15 10 Diced 98 2 0 Easy‐carve shoulder 77 12 11 Loin chop 63 29 8 Mutton Leg 85 9 6 Casserole 90 10 0 The gross composition values show that there generally appears to be less separable fat in the untrimmed raw retail samples collected in 2002 compared with those reported from 1983 to 1986.12, 13 For example, the percentage separable fat has declined from 18% to 12% in rump steak and from 10% to 6.6% in fillet steak. This trend to lower‐fat cuts has been due to three factors: selective breeding and feeding practices designed to increase the carcase lean‐to‐fat ratio; meat classification and marketing systems designed to favour leaner products; and modern butchery techniques such as seaming out whole muscles and trimming away intermuscular fat.14 Given the trend to prepare and consume meat after trimming external fat, the most recent nutritional analyses show that all trimmed lean red meats are relatively low in fat (<7%) and have moderate cholesterol content, with the exception of mince meats (Table 3). An important contributor to the leanness of muscle meat in Australian beef and lamb is that almost all animals are pasture (grass) fed for most of their lives, although some are given short periods of grain finishing before slaughter (D Thomason, MLA, personal communication). Table 3. Fat and cholesterol content of trimmed raw and cooked Australian red meat (per 100 g) Meat cut Total fat (g) Cholesterol (mg) Beef Diced, raw 2.7 54 Diced, cooked 3.0 77 Round steak, raw 1.7 62 Round steak, cooked 2.0 75 Topside roast, raw 4.7 35 Topside roast, cooked 2.8 62 Sirloin steak, raw 1.9 58 Sirloin steak, cooked 3.8 70 Scotch fillet, raw 2.8 58 Scotch fillet, cooked 4.5 70 Regular mince, raw 10.8 76 Regular mince, cooked 12.7 99 Low‐fat mince, raw 6.8 61 Low‐fat mince, cooked 9.0 81 Veal Leg steak, raw 1.5 57 Leg steak, cooked 1.9 85 Cutlet, raw 1.1 35 Cutlet, cooked 2.0 41 Lamb Diced, raw 5.2 78 Diced, cooked 6.5 96 Leg roast, raw 3.2 71 Leg roast, cooked 6.0 80 Easy‐carve shoulder, raw 4.3 54 Easy‐carve shoulder, cooked 5.4 86 Chump chop, raw 4.3 73 Chump chop, cooked 10.2 93 Cutlet, raw 6.7 67 Cutlet, cooked 8.6 96 Lamb mince, raw 6.9 61 Lamb mince, cooked 8.5 93 Mutton Leg roast, raw 4.2 76 Leg roast, cooked 11.4 130 Casserole, raw 3.8 56 Casserole, cooked 7.7 63

Fatty acids While discussion on the fat content of red meat may focus on the saturated fat content, the amount of saturated fat in Australian beef and lamb is actually lower than the total amount of unsaturated fats on a per edible portion basis. Table 4 shows the average fatty acid profiles of beef, veal, lamb and mutton compared with other white meats and fish. Saturated fatty acids comprise, on average, 40% of total fatty acids in the lean component and 48% in the fat component of red meat. In beef and veal, approximately half of the saturated fatty acid in both the lean and fat component of red meat is palmitic acid (16:0), and about a third is stearic acid (18:0). In lamb and mutton, the proportions of these two fatty acids are more similar. There is little variation between cuts in the proportion of fatty acids. Table 4. Fatty acid profile of raw lean meats (g/100 g edible portion) Fatty acid Beef (a) Veal (a) Lamb (a) Mutton (a) Skinless chicken (b) Lean pork (c) White fish (d) Oily fish (e) C14:0 0.096 0.034 0.101 0.060 0.020 0.010 0.020 0.680 C15:0 0.012 0.006 0.016 0.011 0.000 0.000 0.000 0.070 C16:0 0.607 0.215 0.842 0.667 0.340 0.250 0.180 2.170 C17:0 0.028 0.009 0.051 0.036 0.010 0.000 0.000 0.050 C18:0 0.356 0.119 0.644 0.609 0.120 0.130 0.050 0.350 Total saturated 1.149 0.409 1.730 1.464 0.500 0.400 0.300 3.320 C14:1 0.025 0.007 0.004 0.003 0.000 0.000 0.000 0.000 C16:1 0.082 0.033 0.066 0.039 0.004 0.030 0.060 0.590 C18:1 1.103 0.356 1.995 1.370 0.620 0.390 0.110 2.190 C20:1 0.015 0.048 0.010 0.011 0.010 0.010 0.010 1.340 Total monounsaturated 1.205 0.399 2.066 1.413 0.700 0.430 0.200 5.390 C18:2 ω‐6 0.204 0.090 0.321 0.339 0.210 0.120 0.010 0.250 C18:3 ω‐3 0.048 0.022 0.072 0.107 0.010 0.010 0.000 0.130 C20:3 ω‐6 0.020 0.012 0.009 0.009 0.008 0.003 0.000 0.000 C20:4 ω‐6 0.076 0.056 0.094 0.101 0.030 0.019 0.040 0.050 C20:5 ω‐3 (EPA) 0.031 0.028 0.028 0.044 0.005 0.000 0.048 0.913 C22:5 ω‐3 (DPA) 0.051 0.033 0.044 0.053 0.009 0.006 0.021 0.194 C22:6 ω‐3 (DHA) 0.006 0.003 0.013 0.020 0.009 0.004 0.111 1.118 Total polyunsaturated 0.448 0.259 0.603 0.673 0.300 0.200 0.200 2.655 Total ω‐3 0.136 0.086 0.157 0.224 0.033 0.020 0.180 2.355 Total ω‐6 0.300 0.244 0.424 0.449 0.258 0.148 0.050 0.250 Ratio ω‐3/ω‐6 0.45 0.36 0.37 0.50 0.13 0.14 3.60 10.42 Polyunsaturated fatty acids (PUFA) range from 11% to 29% of total fatty acids. Pasture fed beef is a better source of omega‐3 fats than grain feed beef, and this explains the better fatty acid ratio in Australian red meat compared with that in the USA, where there is extensive grain feeding.17, 18 Beef and lamb also have more omega‐3 fatty acids than either chicken or pork, although fish is still a significantly better source than any of the red meats. The recent development of Nutrient Reference Values for Australians recommended a daily adequate intake of long‐chain omega‐3 fats (docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and docosapentaenoic acid) of 160 mg for men and 90 mg for women, with higher targets of 610 mg and 430 mg respectively to reduce the risk of long‐term chronic disease.8 As the levels of long‐chain PUFA found in Australian beef, veal and lamb muscle meat are greater than 30 mg per serving (135 g) of red meat, they are considered a source of long‐chain omega‐3 PUFA according to Australian food regulations (Food Standards Australia New Zealand 2002)1. Mutton muscle meat, which has more than 60 mg EPA + DHA per serving of red meat, can be described as a good source of long‐chain omega‐3 polyunsaturated fats. Red meat is frequently consumed by Australians and makes the second greatest contribution to intake of long‐chain omega‐3 PUFA, after fish, in the Australian diet.19

Trans‐fatty acids Trans‐fatty acids are found in ruminant fat as a result of biohydrogenation by rumen bacteria. Trans‐fatty acids (18:1 trans) in raw muscle meat vary from as little as 22 mg/100 g in veal to 123 mg/100 g in lamb, but is generally less than 3% of the total fatty acid content.15 Levels in both raw and cooked muscle meat are higher in lamb and mutton than in beef and veal.

Choline Choline is a precursor of a number of compounds, including neurotransmitters and membrane phospholipids. Although choline can be made in the body, dietary essentiality has been demonstrated, and the new Australian Nutrient Reference Values recommend an adequate intake of 550 mg/day for men and 425 mg/day for women.8 The best dietary sources are milk, liver and eggs, but meat is also a significant source and beef contains 78 mg/100 g.20

Vitamins As with other animal foods, red meat is an excellent source of bioavailable vitamin B12, providing over two‐thirds of the daily requirement in a 100 g serve (Table 1). Up to 25% RDI of riboflavin, niacin, vitamin B6 and pantothenic acid can also be provided by 100 g of red meat, but compared with pork, it is a relatively poor source of thiamin. Liver is an excellent source of vitamin A and folate, but the levels in lean muscle meat tissue are low. For all these vitamins, older animals tend to have higher concentrations, so the levels in beef are generally higher than those in veal, and mutton has more than lamb. Levels of vitamin D in meat are low and difficult to measure and have often not been included in food composition data previously. However, recent assays of meat in New Zealand have reported levels of 0.10 μg vitamin D3 and 0.45 μg 25‐OH D3 per 100 g in beef and levels of 0.04 and 0.93 μg/100 g respectively in lamb.21 Given the higher biological activity of the 25‐OH vitamin D, this means that 100 g of cooked beef could provide 12% of the estimated adequate intake of 10 μg/day for a 51‐ to 70‐year‐old individual,8 and cooked lamb could provide more than 25%, and hence be an important source of this nutrient, especially for housebound elderly people.