The nutritional and health value of beef lipids - fatty acid composition in grass-fed and grain-fed beef

Abstract

Interest in meat fatty acid (FA) composition stems mainly from the need to find ways to produce healthier meat with a suitable ratio of polyunsaturated (PUFA) to saturated fatty acids (SFA) and a favourable balance between n-6 and n-3 PUFA. Studies of grass feeding versus grain feeding cattle have been conducted in different regions throughout the world and suggest that grass-based diets can significantly improve the fatty acid (FA) composition of beef. Compared with grain diets, grass diets contribute to a lower total fat content and more favourable SFA composition i.e. higher proportion of low density lipoprotein (LDL) and cholesterol-neutral stearic acid (C18:0). Feeding fresh grass compared to concentrates results in higher levels of n-3 PUFA in muscle lipids and a more favourable n-6/n-3 PUFA ratio that is within the nutritional recommendations for the human diet.

Carcass Characteristics and Beef Quality of Young Grass-Fed Angus x Salers Bovines

“…Hence lean and late maturing breeds would have a higher PUFA/SFA ratio than early-maturing breeds when slaughtered at the same carcass weight [ 2 ]. This fact can support our finding that the PUFA/SFA ratio of current animals was 0.23, which can be considered moderate, since beef PUFA/SFA ratio is generally low, around 0.1, except for very lean beef, where the PUFA/SFA ratio can be easily reach the recommended values for human nutrition (>0.4) [ 26 ]. By comparison of the current FA composition with that of grass-fed beef [ 37 ], the current animals presented quite good ω-3 PUFA composition with high content of ALA (51.3 mg/100 g muscle relative to a range of 28.1–52.8 mg/100 g muscle), EPA (11.0 mg/100 g muscle relative to a range of 5.8–24.5 mg/100 g muscle) and DHA (4.3 mg/100 g muscle relative to a range of 1.5–4.2 mg/100 g muscle), despite the fact that these comparisons may depend on genetic makeup, breed, gender, age, and geographic location, which all affect FA compositions [ 27 ].…”

“…By comparison with young Angus or Salers bovines slaughtered over decades in the same processing plant and assessed with the same measurements [ 25 ], the Angus x Salers animals of this study were lean based on fat percentage (19.52% for Angus and 16.07% for Salers versus 15.35% for Angus x Salers). Furthermore, the 2.92% of total lipids of the current animals is generally considered lean [ 26 ]. Grass feeding and the young age of our animals are likely the main reasons for this leanness [ 27 ].…”

Protein and Lipid Digestibility of Pasture-Raised and Grain-Finished Beef: An In Vitro Comparison

“…These results agree with long-known facts on the influence of grazing systems on meat fat. Pasture feeding has been reported to lead to a leaner carcass, reduce intramuscular fat deposition, and improve the fatty acid profile of beef lipids [ 12 ].…”

“…These studies have recognized the differences in the fatty acid composition of the meat, but as yet there is little knowledge in the literature about how red meat is digested in the human digestive tract and how pasture-raised may differ from grain-finished meat, particularly with respect to the kinetics of protein digestion and the digestion and release of lipids, including the fatty acids that are important for health. We have no information yet about the digestion of meat lipids, but it is clear that pasture-raised meat contains significantly enhanced amounts of some of the nutritionally important polyunsaturated fatty acids [ 9 , 11 , 12 ]. Because the structure of the meat is based around protein, higher rates of digestion of protein are likely to influence the release of fat from within the structures, potentially affecting its digestion and bioaccessibility.…”

Assessment of the Effects of Salt and Salicornia herbacea L. on Physiochemical, Nutritional, and Quality Parameters for Extending the Shelf-Life of Semi-Dried Mullets (Chelon haematocheilus)

“…The PUFA to SFA ratio can be used for analyzing the nutritional quality of fatty food materials. Health guidelines recommend that the PUFA to SFA ratio should be above 0.4 for a healthy diet [ 52 ]. This study shows that all of the treatments presented PUFA to SFA ratios of more than 0.4.…”