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165 Cards in this Set
- Front
- Back
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what came first: the chicken or the egg? |
the egg
-first egg was hatched in the ocean |
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what were chickens originally domesticated for? |
fighting -last outlawed in Louisiana in 2007 |
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chickens ancestor |
genetically extinct -originally scavengers and very social animals |
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what two types of chickens are involved in broiler production |
-Cornish: originally used for fighting -White plymouth rock: genetically developed in the united states |
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what is the #1 consumed meat in the US? -why? what is the #1 meat consumed world wide? |
chicken -affordable and abundant Pork |
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what breed of chicken is most common for egg laying? |
white single comb leghorn -lays white eggs |
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why has egg consumption drops from since 2015? |
avian influenza virus |
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air cell |
pocket of air that occurs between the membrane and the shell -develops over time due to pores in the eggs while moisture is leaving -forms at the blunt end of the egg -helps to maintain volume -indicator of age and freshness |
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Egg yolk |
-yellow portion of the egg -30-33% of total liquid weight -major source of egg vitamins, minerals, and fat --all of the cholesterol -surrounded by a clear seal/ membrane aka the vitelline membrane |
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what is the egg yolk? |
hens ova -comes from the hens ovary -contains the DNA |
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Germinal disc |
the hens ova (egg) |
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blastoderm |
fertilized eggs ova -larger -more symmetrical -darker in color |
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blastodisc |
infertile egg ova -smaller -asymmetrical -light in color |
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latebra |
center or the yolk -as rings for it pushed the germinal disc to the edge and makes it easier to get fertilized |
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concentric circles in the yolk |
rings of nutrients that form around the germinal disc -feeds embryo |
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Yolk forms ______________ yolk during the day due to: |
yolk forms yellow yolk during the day due to feeding causing an increase in pigment |
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Yolk forms ______________ yolk during the night due to: |
yolk forms white yolk during the night due to not feeding causing an decrease in pigment |
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Albumin |
-white/clear portion of the egg that consists of 4 layers --Chalaziferous layer (3%) --Chalazae layer (and inner thin) (17%) --Thick Albumin (57%) (major source of egg riboflavin (b-vitamins) and protein) --Thin albumin (outer thin: 23%) (mostly water) |
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where does the albumin come from? |
magnum (largest section of the reproductive tract) -during this only the chalaziferous, chalazae and the thick layers are formed --thin comes at the end (in the isthmus) via osmosis |
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Shell membrane |
inner: thicker than the outer -combined they're .0024 inches thick -made up of keratin |
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where do the shell membranes come from? |
In the 4th section called the isthmus |
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where do the 4th layer of the albumin come from? |
formed after the physical membrane via osmosis -osmosis: hydrostatic pressure forms a nice plump egg with a nice shape |
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Shell |
accounts for 12% of the egg weight -may be blood white or brown (pigment derived from blood; Ooporphins) --no nutritional differences -3 Layers --Mammillary, Spongey and cuticle |
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Mammillary Layer |
attaches to shell membranes |
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spongey layer |
94% calcium carbonate that has 7,000 to 17,000 pores for supplying air to the embryo |
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cuticle layer |
protective covering, added as egg passes through the vagina (clogs the egg shell pores to protect against bacteria) cloaca and vent -deposited at the end of laying -cracked shell= death |
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timeline for egg development |
yolk- infundibulum (15 minutes) albumin- magnum (3 hours) shell membrane- isthmus (1 hour 15 minute) cuticle- uterus (20+ hrs) -30 minutes after laying the hen ovulates again |
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protective barriers during egg production |
-cuticle fills pores but it only exists up to 96 hours --in the US we wash the cuticle off due to aesthetics -shell and yolk membranes contain lysozyme (antibacterial compound) that aids in the lysing of bacterial cell walls -Albumin layers: alkaline (pH is elevated which creates an unfavorable environment for bacteria) --little water/ thick: albumin is mostly water but it is all physically bonded in something making it unavailable |
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candling |
shinning a light through the egg to check the size of the air cell -want a smaller air cell (fresher) |
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AA grade eggs |
thick albumin with a centerd yolk -no cracks or imperfections |
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A grade eggs |
not as thick of an albumin but still good yolk isn't as centered |
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B grade eggs |
Body check eggs: budge in shell that appears cracked but is not. Egg cracked while still inside of the hen but it fixed itself before hatching Flat Spot: 2 eggs met in the uterus and made contact which results in wrinkled eggs Wrinkled Eggs: causes by stress, disease and dehydration Misshaped Eggs |
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what happens with b grade eggs? |
food production will buy them because they do not care about looks and theres nothing actually wrong with them -retail stores (grocery) will not buy due to atheistic |
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Egg abnormalities: Blood spot |
form when the ovary tears during ovulation and accidentally tears a blood vessel |
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Egg abnormalities: Meat Spot |
piece of tissue that was torn from the oviduct |
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Egg abnormalities: Double yolk |
independent of each other means the hen ovulated twice (can be triple yolk) -nothing wrong with them, people just don't like the look of it |
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Egg abnormalities: No yolk |
results in a tiny egg -large meat spot could've stimulated the magnum to begin the process |
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Egg abnormalities: floating air cell |
air cell that moves between shell membranes -2 shell membranes aren't attached -can be caused by dehydration or if the egg is stored improperly |
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as an egg gets older the albumin gets _________ which allows the yolk to _________ throughout the egg resulting in a ____ grade egg |
thinner, spread, B |
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___________ eggs are detected using sound/ vibrations and then they are: |
Cracked, taken cracked fully and pasteurized into liquid egg product |
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Whole egg composition |
-Shell 10% -egg white 66% -egg yolk 33% -Approx. 75% water -12-14% protein -10-12% lipids -1% minerals -1% Carbohydrates -less than .5% vitamins |
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Albumin composition |
-90% water -10% protein -trace amounts of fat -good source of riboflavin -contains most of the protein, niacin, riboflavin, chlorine, magnesium,potassium, sodium and sulfur found in eggs --minerals/ water soluble B-vitamins -carbohydrates (1%) |
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Yolk Composition |
-50% water -17% protein -33% lipids (triglycerides, lecithin(emulsifier) [phospholipids] and cholesterol) -amount of water soluble vitamins increase with the % water -minerals: iron, phosphorous, calcium, manganese, iodine, copper and Zinc -Vitamins: A, D, B12, E, biotin, chlorine, folic acid, inositol etc. --not a lot of vitamin K and C because the chicken makes it internally |
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Xanthophyll |
main yellow pigments |
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conalbumin and phosvitin |
prevents oxidation by binding metal ions that are floating around |
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why do eggs have high biological value? |
they have 18/20 amino acids and all 9 essential ones -DHA omega-3 -more unsaturated fatty acids than saturated |
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one large egg contains __________mg of cholesterol and most of it is found in the _______ |
213, yolk |
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what is the suggested daily intake of cholesterol? why do we need cholesterol? |
300 mg is the suggested daily intake -we need it for the cell membrane and it is a precursor to hormones |
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how many eggs can we consume a day w/o raising out blood-cholesterol levels? |
2 -many factor influence blood-cholesterol levels |
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HDL |
-high density lipoprotein -good type of cholesterol -as it transports it doesn't leak triglycerides into the blood stream |
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LDL |
-Low density lipoprotein -bad type of cholesterol -as it transports it does leak triglycerides into the blood stream -correlated to FA intake and cholesterol intake |
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most of the fats found in eggs are ______________ and _________________ which lower blood:cholesterol levels when they replace saturated |
monounsaturated, polyunsaturated |
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salmonella |
found in the GI track of birds because it is a favorable environment -many types of salmonella and not all are harmful |
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what causes salmonella |
rats infesting farms and interacting with chickens -found on the outside of the egg |
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pasturization |
sterilization via heat -have to be careful because at 149 degrees eggs with cook (proteins will coagulate) -salmonella is dead at 160 degrees however it can only be heated to 140 degrees |
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how to do we kill salmonella |
increase in time-temperature relationship |
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coagulation |
egg protiens denature at 149 degrees -in any food it can change coagulation -foaming of egg whites: pockets of air packaged in proteins |
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emulsification |
bonds between polar and non polar form |
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retarded crystallization |
as a result of emulsifacation -refreezing of ice cream |
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adhesion |
albumin proteins are viscous and sticky -egg wash |
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humectancy |
egg protiens and lipids bind water, retaining moisture in a product and prevents staling |
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therapeutic antibiotics |
only treating sick animals when they're sick |
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sub-theraputic antibiotics |
are given before the animal is sick -prevent disease, helps with better feed conversion -ANTIBIOTIC RESISITANCE --low does of antibiotics |
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Hormones |
-the human body produces hormones in quantities much greater than could ever be consumed by eating any food -the average man or women daily produces 35,000x more hormones than could be present in beed or any other food |
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what level of estrogen or other hormones are present in a birth control pill? |
birth control pills have milligrams of estrogen while animal products/ food have nanograms |
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the majority of meat consumed by humans comes from ____________ animals and __________ species. |
domesticated, aquatic |
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red meat |
animals with aerobic muscle type -beef, lamb, mutton, pork, veal, horse, goat, llama, camal, water buffalo and rabbit |
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white meat |
animals with anaerobic muscle type -chicken, turkeys, ducks, geese and guinea fowl |
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game meat |
non-domesticated animals |
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united states per capita consumption |
1. Chicken 2. Beef (declining) 3. pork 4. Seafood 5. Lamb -trends in availability and price -225lbs meat per person per year -Denmark is the #1 meat consumers --developed countries vs un developed countries |
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benefits of meat in the diet |
-excellent source of proteins --highly bioavailable and digestible (biological value) -excellent source of B-vitmans -contributes to low glycemic index (protein rich: carbohydrate low) --due to a lack of sugar in meats -provides micronutrients with high bio-availabily --iron (heme iron: more bioavailable than normal iron; iron at the core of hemoglobin and myoglobin) -Folic acid (methyl donor) Crucial for DNA and RNA synthesis -Vitamin A (selenium: via GPx which is important in cell health) -Zinc (healing and immune system, also important in cell health) |
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ZIP+B |
Zinc, Iron, Protein and Vitamin B |
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perception of animal welfare can directly impact costumers _________________________ |
purchasing decisions |
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meat is the product of a ________________ |
terminal process |
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opportunities to engage in evaluating animal welfare at various level: ______________, ______________ and _____________ -What are the 2 biggest welfare problems? |
production, transportation and at the abattoir -transportation and at the abattoir |
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Behavior and welfare 3 circles |
-Influences: political, emotion and religion -Natural Science: biology, chemistry and physiology -Social science: sociology, psychology ethology |
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complex tissue composition |
-75% water (protein sponge) -18.5% protein (protein sponge) -3% lipid -1.5% vitamins -1% carbohydrates -1% minerals --similar to human composition |
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glucose (stored chemical energy)= |
locomotion and heat |
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types of tissues in meat |
-muscle -adipose -connective -nervous -epithelial |
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weight vs age |
lowest weight at lowest age highest weight at highest age 1. Conception 2. Parturition 3. puberty (inflection point of growth, 30% mature size in mammals and 70% in humans 4. maturity |
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with age... |
1. muscle stays relatively constant 2. fat increases 3. bone decreases |
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smooth muscle |
-spindle shaped cell -single central nuclei -lacks visible striations -involuntary -lines internal tracks --surrounding gut, blood vessels and glands --cellular elongation without cell fusion (non striated muscles) |
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smooth muscle contraction |
when contracted, the filaments slide together and pull the cell to a more rounded appearance -sheets of smooth muscle cells work together because they are interconnected by gap junctions and connective tissue |
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gap junctions |
openings in a cell membrane tt allow for communication vis shared cytoplasm |
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peristalsis (propulsion) |
a series of wave like muscle contractions that moves food to a different processing stations in the digestive tract |
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segmentation (mixing) |
muscular movement in the small intestine with alternating forward and backward movements that mix partially digested food and juices |
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cardiac muscle |
-branched cells that reach out and make contact with out cells -visible striations -single central nucleus -involuntary --higher proportion of mitochondria for aerobic respiration and ATP production -irregular in shape -a lot of connective tissue that hold it together |
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intercalated discs |
regions where adjacent caradiocytes interlocking and where gap junctions permit electrical coupling between the cells -increase in SA at the point of contact |
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skeletal muscle |
-elongated cell -multiple peripheral (on the outside of the cell) nuclei --interior is filled with filaments -2 stem cells fuse together to start (2 nuclei) which assist in growth and maintaining protein filaments that are hurt when a muscle contacts -most abundant (600 of them) -largest cells -what were eating when we eat meat |
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_______ fuse together to form multi-nucleated _____________ |
myoblast, myotubes |
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why do the nuclei migrate to the peripheral edge |
because they need to synthesize proteins in order to contract |
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actin and myosin |
two protein structures that are involved in contractions -ATPase: breaks down ATP for energy -muscle damage is caused when actin and myosin pull apart |
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sarcolema |
cell membrane |
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muscle fiber |
muscle cell -very long |
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myofibrils |
organization of filaments for proper contract |
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transverse tubules |
invagination that allow for depolarization of the membrane to quickly penetrate to the interior of the cell -depolarization= calcium released that causes disruption of the membrane cell potential |
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membrane potential at rest |
positive charge on outside and negative on the inside -Na, Cl and K |
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action potential |
charges switch position |
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sarcoplasmic reticulum |
calcium storage -essentially the endoplasmic reticulum -cannot have a muscle contraction without calcium to bind to actin and myosin -branching all throughout the muscle cell for releasing Ca |
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cannot relax a muscle if... |
calcium is in the presence of actin |
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sarcomere |
overlapping arrangement of myosin and actin -can have multiple |
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Two things that impact tenderness |
1. Myofibular Proteins 2. Extracellular matrix proteins |
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myofibular proteins |
-proteins inside the muscle cells -contractive (slide/ contracting), regulatory (regulates contraction) and cytoskeletal (holds them together) -#1 palatability factor of meat -contractions/ sliding causes the muscle to get harder due to overlapping proteins |
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Rigor Mortis |
"Stiffness of Death" -when you die the cells in you body are still alive because all they need is oxygen and energy (glucose/ glycogen) -Ca slowly leaks from the sarcoplasmic reticulum in which it is stored because there is nothing to maintain the concentration gradient (high->low) -enzymes begin to break things down (48 hrs to full break down aka resolution period) |
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Calpaan |
activated cir na increase in Ca concentration -fixes muscle cells by getting rid of the damaged muscle |
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Extracellular Matrix Proteins |
-proteins outside the muscle cell -has a greater impact on tenderness -comparison between different muscles with in the same carcass |
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end meat |
parts of animal involved with locomotion -muscles keep damaging themselves and fixing themselves -More connective tissue layers |
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middle meat |
down the back of the animal -not involved in locomotion -less connective tissue= more tender -collagen docent break down without calpaan |
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animals age affect on tenderness |
the older it gets the more connective tissue which mean less tenderness |
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high dry heat vs low humid heat |
-high dry heat: twist collagen and makes it less tender -low humid heat: melts the collagen and makes it more tender |
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affect of appearance in meat |
-one of the most important quality attributes at the point of purchase -color |
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myoglobin in meat |
considered pigment in meat -protein with in meat that binds and stores oxygen (water soluble) -Purge: juices in the bottom of package meat -in the muscle and binds 1 O2 molecule |
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hemoglobin |
-myoglobin is similar to hemoglobin --found in red blood cells and can bind up to 4 O2 molecules (binding for transport) |
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red meats have more _________/ ____________ ____________ |
myoglobin, aerobic respiration |
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Oxymyoglobin |
oxygen is binded to myoglobin on surface of meat -bright pink -Fe++ (ferrous) with O2 on the binding site |
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Deoxymyoglobin |
h2o is bound to iron instead of oxygen -no oxygen on the interior of the meat so its ok -dark purple -Fe++ (ferrous) with h2o on the binding site |
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metmyoglobin |
iron is oxidized (loss of e-) so that now it cannot bind oxygen -changes the whole myoglobin structure but doesn't change taste -brown/grey on exterior |
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what can we do to prevent the onset of metmyoglobin thus increasing shelf life? |
sodium nitrate |
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different species have different colors of meat because of... |
differing levels of myoglobin -aerobic/ anaerobic -old cow meat= darker in color -based on amount of movement and age |
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meat flavor comes from the |
lean |
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species flavor is from the |
fat -various fatty acid profiles |
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taste |
-sweet -bitter -sour -salty -umami |
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smell |
volatile compounds |
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Fatty Acids |
-different fatty acid profiles lead to flavor differences --dependent on length and saturation of FA -fatty acid profiles impact melting point |
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Wagyu Beef |
-breed of cow that has good marbling/ intramuscular fat --40-50% intramuscular fat -cool/ dark environment with no movement allowed -vitamin A depleted= fat synthesis and leads to bad eye sight -very expensive and calorically dense |
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rendering |
every year the north america rendering industry recycles greater than 45 billion pounds of discarded animal products -a value in excess of 6 billion -about 25% is exported --the raw materials processed by the rendering industry each year would make a truck convoy 4 lanes wide from LA to NY |
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edible by products |
-hearts -liver -beef extract -blood -brains -tripe -pig stomach etc. |
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what is milk? |
a white or yellowish liquid consisting of small fat globules suspended in a water solution, secreted by the mammary glands for the nutrition of the new born -provides nutrition and protection for young -partly defines a mammal -unique nutritionally |
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milk composition correlations |
-increase growth rate with increase % protein -increase % fat with increase in need for adipose tissue growth |
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humans are low in protein because humans sugar content is high because |
we develop and grow more slowly the brain needs it for development |
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Caseins |
-nutritional function for young -principle proteins -form spheres called micelles |
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micelles |
-phospholipids that are excellent emulsifiers (oil and water) -dissolving oil into water = polar heads are on the outside -dissolving water into oil = polar heads are on the inside |
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casein in.. -milk -yogurt -cheese |
milk: small micelles yogurt: small and clumps of micelles cheese: clumps of casein |
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when casein is clumped large enough it |
comes out as a solution |
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Rennin |
enzyme found in calf stomach naturally because it doesn't digest the casein -just clumps it together -makes the liquid more solid for slower digestion rate |
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acid and bacteria |
involved in denaturing of proteins for cheese |
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cheese formation |
1. liquid 2. Acid addd 3. enzyme added 4. protein denaturation 5. Whey 6. cheese curds |
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when fat is skimmed off of milk what is left |
skim milk and fat |
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Whey Proteins |
-biological function: not nutrition, used for transport, immunity etc. -acid soluble (are not denatured at pH 4.6) |
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lactoglobin in whey proteins |
-protein in cows milk that we do not have -causes allergies: hives, weezing but can be severe (not the same as lactose intolerance) -transport vitamin A (can bind to hydrophobic fat source |
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lactalalbumin in whey proteins |
needed for lactose synthesis |
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lactoferrin in whey proteins |
-binds iron which makes it antimicrobial |
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immunoglobulins |
antibodies (do not denature with acid because then they wouldn't function and that would be bad) |
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other things that are impacted by whey proteins |
-enzymes, hormones and growth factors |
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whey proteins functions |
human nutraceutical benefits -anticancer, opioid effects -decrease in blood pressure and inflammation |
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lactose |
-milk sugar: provides carbohydrate energy (isn't blood glucose) -regulates milk volume (draws water to it) -made in epithelial cells by enzyme and lactalbumin -used (fermented) bacteria for energy --lactic acid by product used for cheese and yogurt |
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lactase |
enzyme that breaks down lactose into galactose and glucose |
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lactose intolerance |
people do not have the enzyme that breaks dow lactose (lactase) -lactose intolerance is actually the norm --originally we were not made to consume milk past birth |
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milk lipids: Triglycerides |
-bacterial enzymes breakdown -release short-chain fatty acids= RANCID ODOR -glyceryl backbone with 3 fatty acid chains -acetic acid: found in the rumen of cow and it breaks down 6 carbon FA into --Acetate (2c), Propionate (3c), Brutyrate (4c) |
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Alveoli |
-the primary mammary structure responsible for producing milk -basic milk production unit --Single=alveolus --1 million/ cubic inch --billions/ udder -separate blood supply to each alveolus -epithelial cells --line the alveolus --fat, lactose, casein, minerals, vitamins etc. --all cells make all milk constituents-not specialized |
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myoepithelial |
contact to force out milk -oxytocin: hormone response for smooth muscle contraction --capillary ducts to milk ducts to gland cistern (gets bigger until it starts to collect a lot) |
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milking a cow |
1. strip the teat and check for plug/ clog )protects cow from bacteria and prevent mastitis) 2. Treat with cleaning solution 3. milk |
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pasteurized and UHT milk |
-skim, 1%, 2% and 3.25% |
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butter |
average composition: -80% milk fat -16% water -1.2% protein |
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milk processing definition |
according to US code of federal regulations -the lacteal secretion, practically free from colostrum, obtained by the complete milking of one or more health cows which contains -= or greater than 8.25% non fat milk solids -and less than 3.25% milk fat |
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milk processing process |
1. receiving and storage 2. centrifuge 3. standardized (adding fat back) 4. flavor treatment 5. homogenization 6. pasteurization 7. packaging and labeling 8. storage and distribution |
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receiving and storage |
-temperature cooled to 45 degrees F or less within 2 hours -bacterial limits: less then 100,000/ml prior commingling and less than 300,000/ml after commingling -no positive drug residue -somatic cell count less than 750,000 ml |
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centrifugal operation |
-spinning to fractionate and remove anything with density that differs from that of milk -removal of solid impuritie --dust, dirt, dead cells etc. |
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Milk Standardization |
composition standards -% milk fat --whole: 3.25%, 2%, 1% skim (0%) -adding fat back to milk -if more fat is left over then i can be used for butter -% nonfat milk solids --protein, carbs, vitamins and minerals |
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normal milk pasteurization temp vs time |
Temperature (F) Time -161 15 sec -191 1 sec |
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Ultra High Temperature (UHT) milk |
Temperature Time -201 .1 sec -202 .05 sec -212 .01 sec |
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how is pasteurization done |
there is a giant tank that filters into a tube and it gets smaller and smaller to increase the surface area: volume ratio which makes it easier to heat quickly -capillary system |
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Homogenization |
-agitating milk to break apart/ cream layer unit the fat molecules are distributed evenly -pressure of 1700-2500 psi -temperature above 100 F - the reduction of fat globules |
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packaging |
-convient -attractive -informative |
