Nutritive Value of Meat ANSC 3404 Texas Tech University Why Beef? American Heart Association 1
Issues People today are concerned about: Limiting dietary fat Cholesterol High Blood Pressure Getting the proper vitamins and minerals Losing weight Actually, lean beef fits into a healthy diet to achieve these goals Beef provides the nutrients you need to stay healthy and energetic Percent Daily Values from 3 ounces of Lean Beef Protein 50% Zinc 32% Phosphorus 20% Thiamin 6% Riboflavin 12% Niacin 19% B-6 18% B-12 15% Iron 15% Based on a 2000-calorie diet 2
What about the fat in beef? According to ADA, you should not eliminate fat entirely from your diet Fat is an essential nutrient Fat supplies energy and transports vitamins Just don t overdo it! Compared to chicken, many beef cuts contain as much or less fat. The skinny on Beef Fat Cut Saturated fat,g Total fat, g Chicken breast 0.9 3.0 Eye of round 1.5 4.2 Top round 1.9 5.5 Round tip 2.1 5.9 Top sirloin 2.4 6.1 Bottom round 21 2.1 63 6.3 Top loin 3.1 8.0 Tenderloin 3.2 8.5 Chicken thigh 2.6 9.2 3
Beef Beef can actually help regulate fat in the diet because, ounce for ounce, it can be just as lean as chicken Why? Today s cattle are leaner and fat is trimmed more precisely Average roast today has 30% less fat than 10 years ago. Steps you can take to control how lean beef is: Buy cuts from the loin and round Buy 90% lean ground beef Trimming visible fat from cuts prior to cooking will reduce fat by 50% Use low fat cooking methods Steaming, baking, broiling, roasting, braising, grilling Serve reasonable portion sizes. 3 ounces is the size of a deck of cards. 4
The Amount of Fat Recommended on a Daily Basis Daily caloric intake Total fat, g Age/activity level 1600 calories 53 Many sedentary women; some older adults 2200 calories 73 Most children; most teenage girls; most active women; many sedentary men 2800 calories 93 Most teenage boys; many active men; some very active females The ADA recommends that people watch the total fat in your diet rather than fretting over the fat content of an individual food. Beef Calorie for calorie, Beef has more nutrients than many other foods Iron Zinc Phosphorus B-complex vitamins 5
Iron The US Centers for Disease Control estimates that approximately 700,000 toddlers and 7.8 million women in the US have iron deficiencies Iron helps deliver oxygen to your cells and muscles Iron from beef (heme iron) is more easily used by the body than iron from plants Iron To get the Cups Food same amount of iron as that 2 1/3 Canned kidney beans found in 3 ounces of 5 ¼ Raw spinach cooked sirloin, you have to 10 ½ Raw broccoli consume: 21 Cooked corn 6
Zinc Related to enzyme function Cell replication Hormone activity Immune system needs zinc to resist infection Phosphorus Phosphorus is needed for: Strong teeth Strong bones Mineral balance 7
B-complex Vitamins Most abundant in red meat B-12 is not found in plants Meat supplies: B-6, B-12, thiamin, riboflavin, niacin Nitrites 8
Nitrite / Nitrate Functions Stabilize color of lean tissue Provide characteristic flavor Inhibits growth of a number of food poisoning and spoilage bacteria Retard the development of rancidity Most important effect on microbial growth Clostridium botulinum Levels of Nitrite and/or Nitrate Allowed in Curing Different Meat and Poultry Products Product Ingoing level l as Ingoing level l Residual level l of NaNO 2 as NaNO 3 NaNO 2 allowed Bacon pumped 120 ppm None 40 ppm Bacon cvr pick 200 ppm None 40 ppm Cooked sausage 156 ppm None 100 ppm Dry and Semidry 625 ppm 1719 ppm 100 ppm Dry cured cuts 156 ppm 2188 ppm 100 ppm Pickle cured cuts 200 ppm 700 ppm 100 ppm Sterile canned 156 ppm 1719 ppm 120 ppm Baby foods None None None 9
Nitrosamines Nitrous oxide is formed by breakdown of nitrite. Secondary amines are present in meat CH 3 CH 3 NH + HONO N-NO+H 2 O CH 3 CH 3 Dimethylamine Nitrous acid Dimethylnitrosamine Nitrosamines Nitrosamines have been isolated in small amounts in all cured meats after cooking Nitrosamines have been shown to be carcinogenic Delaney Amendment of the Pure Food and Drug Act Food additives that cause cancer must be removed from the food supply 10
Nitrosamines FDA works closely with meat processors to control levels in cured meats Still permits its use because of prevention of C. botulinum growth Risk less than that of botulism poisoning if removed FDA restricts addition of nitrite in premixes Nitrosamines Bacon a concern because of preparation Bacon is likely to be scorched and this promotes nitrosamine formation N-nitrosopyrrolidine is nitrosamine of concern in bacon Erythorbate and ascorbic acid reduce formation of nitrosamines 11
Salt Sodium Salt (NaCl) causes hypertension in 20% of Americans, so efforts are made to reduce sodium level Sodium (Na) ion causes the hypertension High salt levels in processed meats Na level dropped in baby foods during 70 s because of voluntary action 12
Salt Salt is basic ingredient in all curing mixtures Only necessary ingredient Salt preserves through dehydration and changes in osmotic pressure, which inhibits bacteria growth and subsequent spoilage Salt Recent emphasis on salt reduction KCl substitute for part of NaCl Reduced sodium must be 1/3 less sodium for labeling KCl must not exceed 50% Flavor 60% NaCl / 40% KCl normal; 34-35% reduction KCl reduces blood pressure 13
Cholesterol Cholesterol in Meat Occurs as free (non-esterified) or combined with a fatty acid (esterified) Lean beef, pork, lamb have 70-75 mg / 100 grams (90% is non-esterified) Fatty tissues have similar amounts 14
Cholesterol Blood cholesterol levels are related to coronary heart disease Consumers equate blood cholesterol levels to dietary cholesterol levels Little evidence of a relationship Cholesterol and Fat 15
Contribution of animal fats Fat s major contribution to the diet is energy or calories Fat has 2.25 X as much energy as an equal amount of protein or carbohydrate Fat supplies essential fatty acids Linolenic, i linoleic, l i and arachidonic i Linoleic in excess can be converted to arachidonic Animal fat and cholesterol Reports have related animal fat in the diet to heart disease and other circulatory disorders Cholesterol is found in the plaques that line arteries of patients with heart disease Subsequent reports showed that high h levels of unsaturated fatty acids in the form of vegetable oil reduced blood cholesterol levels Suggesting that saturated fat is the culprit 16
Animal fat and cholesterol No scientific evidence linking animal fat No scientific evidence linking animal fat consumption and the incidence of heart disease Cholesterol is produced by body when not supplied Other factors: heredity, lack of exercise, obesity, smoking Not accounted for in most studies Reduction of cholesterol, however, is easier if excess fat eliminated 17