Nutrient analysis of USDA Prime beef cuts
Beef carcasses graded as United States Department of Agriculture (USDA) Prime have increased from 3.3% of total graded carcasses in 2000 to 10.3% in 2020. Updated and accurate nutrient information is needed for USDA Prime beef cuts which are becoming increasingly available in the retail, wholesale and foodservice sectors. Additionally, the number of USDA Prime beef cuts represented in the USDA nutrient database is not representative of the cuts available to consumers. The objective of this study was to provide a complete nutrient profile for the most frequently purchased USDA Prime beef cuts and to compare nutrient values across cut type. Strip loin steaks, tenderloin steaks, ribeye steaks, top sirloin steaks and rib roasts (NAMP Meat Buyer’s Guide # 1180, 1190A, 1184B, 1112A, and 112A, respectively) from USDA Prime beef carcasses were collected from 6 geographical locations during 3 seasonally spaced collections. Analyses were conducted on each retail cut in both raw and cooked state (N = 180; 5 Prime beef cuts × 6 locations × 3 collections × raw, 5 Prime beef cuts × 6 locations × 3 collections × cooked ). Steaks designated for cooked evaluation were pan grilled and rib roasts were oven roasted. All cuts were dissected into separable lean, seam fat, external fat and refuse components. For laboratory analyses, separable lean of each retail cut, from each of the six locations were homogenized and composited together by collection (n = 3 per combination of cut and cook type) for both raw and cooked cuts. Raw ribeye steaks and rib roasts were composited together, while cooked ribeye steaks and rib roasts were composited separately because of different cooking methods. Cooked and raw separately, seam and external fat dissected from all cuts were homogenized together per collection (n = 3 for raw fat; n = 3 for cooked fat). Proximate composition (crude protein, lipid, moisture and ash), fatty acid profile, amino acid profile, mineral content, cholesterol content, fat soluble vitamin content, and B-vitamin content were determined for each composited sample (N = 33). Two Prime cuts--tenderloin steak and top sirloin steak--qualified as “lean,” by USDA standards, with less than 10 g total fat, less than 3.5 g saturated fat and less than 95 mg cholesterol. Percent lipid of strip loin steaks and rib roasts were not different (P >0.05); however, lipid content of strip loin steaks and rib roasts was greater than that of tenderloin and top sirloin steaks (P ≤ 0.01). Strip loin steaks and ribeye cuts did not qualify as lean because of elevated total fat and saturated fat content. Nonetheless, all Prime cuts evaluated qualified as an excellent source of protein, selenium, niacin and vitamin B12 (containing greater than 20% of the respective daily value as established in the Dietary Reference Intakes). Furthermore, all five Prime beef cuts qualified as a good source (containing 10-19% of the respective daily value established in the Dietary Reference Intakes) or excellent source of thiamin, riboflavin, pantothenic acid, vitamin B6, phosphorus and zinc. Fatty acid analysis identified oleic acid (18:1cis9), palmitic acid (16:0), stearic acid1 (18:0) and essential linolenic acid (18: 2 n-6) in the greatest concentrations across all cuts. Of the fatty acid fraction, “heart healthy” monounsaturated fatty acids, as established by the American Heart Association, comprised 49%, 48%, 50%, and 44%, in the raw, separable lean portions of strip loin steak, tenderloin steaks, top sirloin steaks and rib roasts, respectively. Stearic acid, which is a saturated fatty acid having neutral effects on serum cholesterol levels, was 27%, 31%, 30% and 29% of the saturated fat portion of separable lean components of strip steaks, tenderloin steaks, top sirloin steaks and rib roasts; respectively. Prime beef was a good and excellent source of protein, as well as multiple essential vitamins and minerals. While only two evaluated cuts qualified as “lean,” all cuts contained heart healthy saturated fatty acids. Nutrient data from this study could be used to update USDA Food Data Central, which is pertinent for informing health professionals, dietitians, food label regulators, legislators, and consumers.