NFS 53 1st EditionExam # 2 Study Guide Lectures: 11-17Lecture 11 (February 19)I. Meat Structurea. Meat is made up of muscle fibersi. Made up of myosin and actin ii. These proteins, when activated, slide past each other to shorten the entire fiber, and thus thicken and shorten, or contractb. Fati. Muscles use fat as an energy store, in particular redii. Fat contributes to richness and mouth-coating smoothnessc. Carbohydrates (mostly glycogen)i. Some muscle tissues use glycogen, a carbohydrate stored directly in the cells, for anaerobic metabolism, which produces lactic acidLecture 12 (February 24)An introduction to Grass-based Dairy and Beefa. Beef:i. Grain- 6-12 months pasture, feedlot/CAFOii. Grass- on pasture onlyb. Dairy:i. Grain- a confinement barnii. Grass- come back to barn from pasture for milkingII. System Perspective -sun/rain→grain/grass→cow→milka. Grain Cropi. Purchase a lot of equipmentii. Buy seed/ other growing suppliesiii. Runoff is a huge problem1. Sediment, nitrogen, phosphorusb. Grass Cropi. Perennial forageii. Only plant onceiii. Easy/cheapiv. Cows eat and fertilizev. Cows congregate in one area, thus creating management grazingc. Rotational grazingi. Great infiltration of water into the soilii. Decreases pollution/runoffiii. Reverse atmospheric carbon build upd. Animal Healthi. Better digestive health1. Lower stomach acidity2. More beneficial microorganismsii. Less lameness/mastitisiii. This means a total lower monetary coste. Downsidesi. Milk yield is lowerii. Size up time takes longeriii. Price for consumer is higher1. Cow pooling- a way to cut costBuying a cow with other people and splitting itf. USDA “Grass-fed” definitioni. Must be fed only mothers milk and forageii. Forage can be pasture or stored (ie hay)iii. Definition is needed because producers were falsely marketing their beefiv. Weakness of the definition1. Can be confined to a pen and fed dry hay2. Does not prohibit antibiotics or hormonesg. USDA organic certifiedi. No antibiotics or hormonesii. “Pasture Rule” 20101. Free access to pasture2. At least 120-day grazing season3. 30% dry food must be from pastureh. American Grass-Fed Associationi. 3rd party certificationii. Stricter than USDAiii. Requirements1. Fed only grass/forage2. Raised on pasture3. No antibiotics or hormones4. Lives on an American FarmIII. Health benefits of grass-fed meat and dairya. Less overall fat and caloriesb. Healthier composition of fatsc. More omega-3/ conjugated linoleic acidd. Less omega-6e. More antioxidants (ie beta-carotene, vitamin E, zinc)IV. Flavor profilea. Deeper flavorb. More beefyc. Mineral notesd. Flavor depends on environmente. Cleaner, earthier flavorf. More lean-less oily mouthfeelI. Cooking considerationa. Pan sear the meatb. Be careful not to overcook because it has less fatc. Best cooked rare/medium rared. Cook 70% as long as regular beefe. Add moistureII. Meat structureSkeletal- tubular muscle fibers connected togetherSmooth- more flattened out fibers connectedCardiac- spaced out tubular fibers connected by small horizontal fibersa. Connective tissuei. Connects individual cells and tissues to each otherii. Holds muscle fibers together that organize into sheetsb. Protein filamentsi. Run through connective tissuesii. Collagen1. Found in tendons2. Makes up 1/3 of protein3. Hydrolyzed to gelatin in water and becomes tenderiii. Elastin1. Found in ligaments and blood vessels2. Toughc. Fati. Fatty tissue or cover fatii. Marbling-intramuscular fatd. Bonei. May help identify location on carcasse. Texture and tastei. Tough meat is really a resistant texture.ii. Tough meat can come from muscle fibers, amount of connective tissue and amount of marbling fat.iii. Tender cuts from back of animal, less active muscles. Examples: rib, t-bone, wedge. iv. Less tender cuts from shoulder and hip, more active muscles. Examples: blade and round boneLecture 13(February 26)I. Cuts of meata. Most tender cuts i. Rib, T-bone or loin, and wedge or sirloinb. Medium tender cutsi. Chuck or arm - shoulder area, rump - hind leg area, and roundc. Least tender cuts i. Flank, plate, brisket, neck, shankii.II. Tenderizing techniquesa. Enzymes - digest proteins and cause Tenderization: papain, bromelin, ficin.Caused by general hydrolysis. b. Mechanical - pounding, grinding, cubing.Accomplished by breaking fibers.c. Acid - hydrolyzes proteins such as a marinade.d. Salts – retain moisture and break down compounds surrounding muscles whichcauses the release of protein.e. Hydration of connective tissue by cooking in moisture.III. Storagea. Best if stored below 36 F or at least refrigerator temperatures. Maximum refrigerator storage is 3-5 days, however, ground or variety meats should be usedin 1-2 daysb. Should be wrapped as not to absorb odors from surrounding foods.IV. Poultrya. Turkey, chicken, goose, duckV. Meat cookerya. Dry heat - used on tender cuts of meat that contain a high proportion of muscle tissue. Examples: roasting or baking, broiling, sauté, deep fat fryingb. Moist heat - used for less tender cuts of meat that contain more connective tissue like collagen and elastin which soften in moisture. Examples: braising, stewing, boiling, slow cookingVI. Fish classificationa. Vertebrate versus Invertebrateb. Salt- or Freshwaterc. Lean or FatVII. Vertebrate: fish with finsa. Lean: <5% fat in edible fleshi. Examples: cod, flounder, bluefish, sole, haddock, pike, perchb. Fatty or not lean: >5% fat in edible flesh i. Examples: eel, trout, salmon, shad, mackerel, lake bass, sturgeonVIII. Shellfish or Invertebratesa. Mollusks - partially or wholly enclosed in hard shell i. Examples: oysters, clams, abalone, scallops, musselsb. Crustaceans - covered with crust-like shell and segmented bodies i. Examples: lobster, crab, shrimp, crayfishIX. Compositiona. 18-20% high quality proteinb. Low in fat and cholesterolc. Fat is most unsaturatedd. 30-45% omega-3 fatty acids with 8-12% being eicosapentanoic acid (EPA)e. Fish are good sources of zinc, iron, and copper with marine fish being a good source of iodineX. Storagea. Store below refrigerator temperatures (30 F) for only 1-2 days and covered tightlyto prevent contamination of other foods.XI. Market Formsa. Drawn fish - entrails removedb. Dressed - scaled, eviscerated, heads, tails, fins removedc. Steaks - cross section of dressed fishd. Fillets - side cut off fish lengthwise away from back bonese.