FDSN524 Midterm 1 Word Scramble
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| Vitamins | Compounds essential for the metabolic process of animals; participate in reactions but not consumed (catalysts) |
| Name the fat soluble vitamins. | A, D, E, K |
| How do human's get get most of their vitamin K? | Intestinal bacteria |
| Vitamin K is required in the body for _________. | blood clotting factors |
| Vitamin A is a crucial component of _________. | vision |
| 11-cis rentinal binds to ______ to form ________, which is important for rod cells and night vision. Light breaks down ______ and sends signal to the optic nerve. | opsin, rhodosin, rhodosin |
| What is carotenemia? | Excess beta-carotene in the blood |
| What does vitamin D deficiency lead to? | Rickets; pliable bones |
| How does the body produce vitamin D? | pre-vitamin D from sun > exposed skin convers to vit D > vit D converted to 25-hydroxyvitamin D in liver > kidneys convert to 1,25-dihydroxyvitamin D (hormone) |
| What does excess vitamin D lead to? | Hypercalcemia, kidney stones, calcification of soft tissues. |
| What is the primary role of vitamin E? | Antioxidant |
| What are free radicals? | Molecules with an unshared electron |
| What can vitamin C deficiency lead to? | Scurvy (bleeding gums, impaired wound healing) |
| What can a thiamine (B6) deficiency lead to? | Beriberi (loss of appetite, cardiovasicular symptoms) |
| What is the role of riboflavin (B2) in the body? | Energy metabolism; component of FAD and FMN cofactors |
| What can a riboflavin (B2) deficiency lead to? | Cheilosis (inflammation/small crack on corners of mouth), dermatitis |
| What can deficiency in niacin (B3) lead to? | Pellagra |
| What is the function of pyridoxine (vitamin B6) in the body? | Coenzyme in aa metabolism; synthesis of heme |
| What is the function of folic acid (B9) in the body? | Involved in nucleic acid synthesis |
| What can a folic acid (B9) deficiency lead to? | Anemia, neural tube defects |
| What is the function of iron in the body? | Part of hemoglobin in blood |
| What is the function of sodium and potassium in the body? | Nervous system function |
| What is the function of magnesium in the body? | Functioning of nerves and muscles |
| What is the function of iodine in the body? | It is required for thyroid hormone. |
| Recommended Dietary Allowances (RDA) | Amounts of essential nutrients considered adequate to meet the nutritional needs of most health people in the US |
| Daily Reference Values (DRV) | A set of dietary references for fat, saturated fat, cholesterol, carbohydrates, protein, fiber, sodium, and potassium |
| Reference Daily Intake (RDI) | A set of dietary references based on the RDA for essential vitamins and minerals and, in selected groups, protein |
| Daily Value (DV) | Appears on food labels; made up of DRVs and RDIs |
| Fortification | Addition of nutrients to render the food a "good" source; may include addition of nutrients not normally found in the food. |
| Enrichment | Addition of nutrients in accordance with a standard identity as defined by the FDA. |
| Bioavailability | The degree to which an ingested nutrient undergoes intestinal absorption and metabolic function in the body |
| What are the functions of fat in the body? | Energy storage, insulation, cell membranes, etc. |
| What are the functions of fat in food? | Texture, emulsions, flying, carrier of flavors/colors |
| What is the most common type of fat in both foods and the body? | Triglycerides |
| Fatty acids | Long chain carboxylic acid; building blocks for triglycerides and phospholipids |
| Glycerides | Fatty acids esterified to glycerol (e. 2 fatty acids + glycerol = diglyceride) |
| Are short-chain fatty acids liquid or solid at room temperature? | liquid |
| Are long-chain fatty acids liquid or solid at room temperature? | solid |
| What is the difference between a monounstaurated fatty acid and a polyunsaturated fatty acid? | Monounsaturated has one double bond, polyunsaturated has two double bonds |
| What is the difference between an omega-3 fatty acid and an omega-6 fatty acid? | The location of the first double bond |
| What are the two essential fatty acids? | alpha-linolenic, linolenic |
| Rancidity | Spoiling of fats through oxidation |
| How can rancidity be reduced in foods? | Adding antioxidants, limiting exposure to heat/light/oxygen, hydrogenation |
| What is "C" nomenclature? | [number of C atoms]:[number double bonds] - eg. C18:6 |
| What is "omega" nomenclature? | omega-[position of double bonds from methyl end] - eg. omega-3,6,9 |
| How are trans fats made? | Hydrogenation of vegetable oils. |
| What are the ways of assessing oil properties? | Refractive index, iodine value, melting point, peroxide value, color, polar material, fatty acid composition, trace metals, smoke point, melt point |
| T or F: The higher the melting point, the more stable the molecule. | True |
| T or F: The longer the chain and the fewer the double bonds, the lower the melting point. | False |
| T or F: Corn oil has a higher melting point than lard. | False |
| Plastic range | Temperature range over which a fat exhibits plasticity |
| What different methods are available for altering plastic range? | Interesterification, hydrogenation, mixing different fats, adding emulsifiers |
| Interesterification | Process of heating a fat in the presence of a catalyst to hydrolize the fatty acids and re-esterify them with glycerol |
| Superglycerination | Process of incorporating 3-6% emulsifier into shortening to improve baking qualities |
| What are the advantages of hydrogenation? | Decreases susceptibility to oxidation; raises melting point |
| What are the advantages of interesterification? | Prevents large crystals; fat has wider plastic range |
| Autooxidation of lipids | The oxidative deterioration of unsaturated fatty acids via an autocatalytic free radical chain mechanism |
| How is a lipid radical formed? | Hydrogens are removed from the lipid closest to double bonds |
| Name the initiation mechanisms of autooxidation of lipids? | Photosynthesized oxidation, metal catalysis, thermal oxidation, enzymatic oxidation |
| What is the difference between a primary and a secondary antioxidant? | Primary: free radical acceptors that delay or inhibit the initiation/propogation steps Secondary: Do not convert free radicals to more stable products |
| T or F: The more time a food spends being fried in oil, the decrease in unsaturation. | True |
| What is the general structure of a protein? | NH2-CHR-COOH |
| Which proteins are considered amphiphilic? | glycine, alanine, tryptophan |
| A protein at a low pH will be _______. | protonated |
| A protein at a high pH will be ________. | deprotonated |
| Isoelectric point | pH at which the positive and negative charges on an amino acid are in balance (ie. zero net charge) |
| T or F: Proteins are least soluble at their isoelectric point. | True |
| What are the essential amino acids? | PVT TIM HALL |
| What is the name of the bond which links amino acids together to form proteins? | peptide bond |
| What two atoms participate in a peptide bond? | alpha-carbon on one amino acid and alpha-amino group on the other amino acid |
| T or F: The protein backbone unit consists of repeating N-C-C units. | True |
| Name the non-covalent bonds in proteins. | Van der Waals forces, electrostatic forces, hydrogen bonds |
| Name the covalent bonds in proteins. | disulfide linkages, peptide bonds |
| Primary protein structure | Linear sequence of amino acids linked via peptide bonds |
| Secondary protein structure | Spatial arrangement of amino acid residues at certain segments of the chain; alpha-helix, beta-sheets, random |
| Random coil | A secondary structure with no regular or ordered pattern along the polypeptide chain |
| Tertiary protein structure | Polypeptide folds into a compact 3D form - usually globular or fibrous |
| Name examples of fibrous proteins. | Collagen, actin/myosin |
| Name examples of globular proteins. | Myoglobin, whey proteins, caseins |
| Quaternary protein structure | Protein contains multiple polypeptide chains |
| Disulfide linkage | Covalent linkage between two cysteine residues, forming cystine |
| What are the different functions of proteins in food? | Texture, appearance, flavor, nutrition, toxicity |
| Denaturation | Disruption of any of the higher order structures of the protein without disrupting the primary structure |
| What are different causes of denaturation? | heat, acid, salts, mechanical action |
| What are the effects of denaturation? | decreased solubility, loss of function, increased susceptibility to proteases |
| Where does gelatin come from? | Collagen - connective tissue in animals |
| What are the steps of gel formation? | Powder is dispersed in water and heated, gelatin cools and viscosity increases, liquid changes to viscoelastic solid |
| Acid | Any substance that can donate a proton |
| Base | Any substance that can accept a proton |
| What is the equation for the dissociation constant (pKa)? | pKa = -log(Ka) |
| What is the difference between a weak and a strong acid? | Strong acids have a larger extent of dissociation. |
| Total acidity | Both ionized and unionized H+ atoms; aka titratable acidity/normality |
| Active acidity | Ionized H+ atoms; = normality * rel. amount ionized; measured by pH |
| Normality | [molarity][number of ionizable H+ atoms] |
| Molarity | moles/L |
| What is the equation for pH? | pH = -log[H+] |
| What is the Henderson-Hasselbalch equation? | pH = pKa + log[A-]/[HA] |
| Equivalence point | When chemically equivalent quantities of acid and base have been mixed |
| Catalyst | Substance which changes the rate of a chemical reaction without appearing in the end products |
| Coenzyme | A non-protein substance required by some enzymes as a co-factor; can be organic or inorganic |
| Energy of activation | Energy needed for a reaction to proceed |
| What are some roles of carbohydrates in foods? | Source of energy, sweetness, browning reactions |
| What are the two classifications for monosaccharides? | aldoses and ketoses |
| What are the two classifications for polysaccharides? | homo and hetero |
| Aldose | A monosaccharide containing an aldehyde group |
| Ketose | A monosaccharide containing a ketone group |
| What models are using to represent monosaccharides? | Fischer projection, Haworth projection, chair conformation |
| D-configuration | On a monosaccharide the hydroxyl (OH) group is to the right of the last stereocenter on a Fischer projection |
| What is the formula for determining the number of stereoisomers? | 2^n where n is the number of chiral carbons in the molecule |
| Epimers | Molecules which differ in configuration around one specific C-atom |
| Anomeric carbon | The carbon atom apart of the carbonyl group |
| What is the difference between alpha and beta anomers? | The OH group differs in their configuration around the amomeric carbon (alpha = right, down, axial; beta = left, up, equatorial) |
| Hemiacetal | An aldehyde which reacts with an alcohol |
| Hemiketal | A ketone which reacts with an alcohol |
| When the C1 aldehyde and C5 OH of glucose react, what happens? | Cyclicization - forms an intramolecular hemiacetal (pyranose ring) |
| What are the two ways to form fructose? | 6 member pyranose ring: C2 keto group with OH on C6 5 member furanose ring: C2 keto group with OH on C5 |
| What larger molecules can glucose be found in? | Sucrose, lactose, starch, glycogen, and cellulose |
| Which monosaccharide is the sweetest? | Fructose |
| Which monosaccharide is an epimer of glucose? | Galactose |
| How are glycosidic bonds formed? | The hydroxyl group on one monosaccharide reacts with the hydroxl on another |
| What two monosaccharides make up lactose? | glucose and galactose |
| What are some differences between alpha- and beta-lactose? | alpha-lactose is more soluble, beta-lactose is hygroscopic (not suitable for forming tablets -> little commercial use) |
| What is the amorphouse form of lactose? | It is non-crystalline and obtained by spray drying; very hygroscopic |
| Explain lactose intolerance? | Lactase enzymes in the intestine are decreased; undigested lactose gets broken down by intestinal bacteria and causes gas/cramping |
| What two monosaccharides make up sucrose? | glucose and fructose |
| What is invert sugar? | Invert sugar is created by the hydrolysis of sucrose by microorganisms or acid and splitting into glucose and fructose |
| What is galactosylsucrose? | Sucrose derivatives comprised of sucrose linked by glycosidic bonds to glycosyl units |
| Reducing sugar | Sugars having free anomeric hydroxyl groups and can participate in chemical reactions |
| Name the reducing sugars. | glucose, fructose, maltose |
| Cyclodextrin | formed by soluble, partially hydrolyzed starch polymers; hydrophobic core and polar exterior |
| Name two purposes of cyclodextrins. | bind flavors, lipids, and color compounds; bind undesirable constituents; to stabilize against chemical oxidation |
| Polyols | not true sugars which lack a carbonyl group; sugar alcohols; can be formed by reducing sugars |
| What are unique properties of polyols? | negative heat of solution - cooling sensation in mouth when consumed; does not undergo browning; lower calorie count/gram; non carcinogenic; slow GI absorption |
| Polysaccharide | Complex carbs made up of several monosaccharides |
| What is starch made up of? | glucose; amylose/amylopectin |
| What is the structural difference between amylose and amylopectin? | Amylose has a linear structure which forms a helix; amylopectin has branches |
| Birefringence | The refraction of polarized light by the intact crystalline regions give a "maltese cross" pattern which disappears upon heating/gelatinization |
| Describe the solubility of starch. | Insoluble in cold water, more soluble in heated water; gelatinization point is where crystallinity is lost |
| Imbiption | When starch granules swell when heated with water. |
| Describe the gelatinization of starch | Imbiption, H-bonds break causing amylose to spill from the starch granule, the granules lose their integrity, when cooled, junction zones form between amylose and amylopectin, water is trapped forming a gel |
| What are factors affecting starch gelatinization? | Temperature, agitation/stirring, addition of acid, addition of other ingredients, enzymes |
| Retrogradation | Occurs when starch chains re-associate into an ordered strcuture > crystalline order |
| T or F: Short-term retrogradation occurs with amylopectin, long-term retrogradtion occurs with amylopectin | True |
| Synersis | As gel dehydrates, junction zones tighten and water is "squeezed" from the gel |
| Name three types of starches. | Cornstarch, tapioca, potato |
| Name the four types of modified starches. | Hydrolysis or acid-converted (low viscosity), cross-linked or cross-bonded (resisitant to shearing + greater heat tolerance), substitution or stabilization (prevents retrogradation + reduces synersis), physically modified (absorb cold water - pudding!) |
| Name the four types of resistant starches. | RS1 RS2 RS3 RS4 |
| What are resistant starches used for in foods? | Increase fiber content |
| Where is glycogen stored in the human body? | Liver and muscles |
| Glycogen is identical in structure to _________ but _______ occurs making it different. | amylopectin, more branching |
| Glycogen can be hydrolyzed to _________. | Glucose |
| What monosaccharide makes up cellulose? | Glucose |
| The structure of cellulose is similar to _______ but _______ changes the 3D shape to be _________. | amylose, glycosidic bonds, straight |
| Why is cellulose considered an insoluble fiber? | Humans lack cellulase to hydrolyze beta 1->4 bond |
| What is carboxymethyl cellulose? | chemically modified cellulose which does not occur naturally in plants; aka cellulose gum (increases water solubility/thickening agent) |
| What are pectic substances? | cell cementing substance; linear polymers of galacturonic acid |
| Name three pectic substances. | Propectin, pectinic acid, pectic acid |
| What are pectins? | high-MW pectinic acids that are dispersible in water; classified as high methoxyl and low methoxyl |
| What is required for pectin jelly? | Pectin, water, sugar, acid |
| What are gums? | polysaccharide substances derived from plants; typically contain galactose |
| Gums are also known as __________. | hydrocolloids |
| What are the functions of gums in foods? | Gelation, viscosity, emulsification/stability, whipping, suspension, freeze thaw protection |
| What are some of the functions of water in foods? | Ingredient, solvent, gelatinization of starch, plasticizer, microbial spoilage, medium for heat, cleansing agent |
| Sustainibility involved equitable distribution of _______ and ________. | resources, opportunities |
| T or F: Water is the one molecule that does not have a dipole moment. | False |
| T or F: Water can act as both an acid and a base. | True |
| Equilibrium constant of water equation: | Kw = [H3O+][HO-]/[H2O]^2=10^-14 |
| T or F: Water may be adjusted to be alkaline to minimize corrosion of pipes and deposition of carbonates. | True |
| Gibb's free energy equation: | deltaG = H-TdeltaS |
| Specific heat | The amount of energy (heat) per mass unit required to raise the temperature by 1 degree Celcius; Q=mcdeltaT (Q is energy, c is specific heat) |
| Latent heat | The amount of energy (heat) required to bring about a phase change at constant temperature and pressure (L=Q/m) |
| Name the phase transition steps to go from solid to gas. | Heat of fusion, latent heat of fusion, heat of vaporization, latent heat of vaporization, vapor |
| What is the physical state of water in the heat of vaporization stage? | Liquid |
| Exothermic | Product has less energy than the starting material |
| Endothermic | Product has more energy than the starting material |
| T or F: In an endothermic reaction, the starting material loses heat and the surrounding material or environment gains heat. | False |
| Sensible heat | Heat that results in a change in temperature (measured with a thermometer) |
| Wet bulb temperature | Temperature indicated by a moistened thermometer bulb exposed to the air flow; measured the extent of cooling as moisture dried from a surface |
| What are the advantages to wet bulb temperature? | Measures true thermodynamic temp, determined relative humidity, psychrometric charts are available |
| T or F: The wet bulb temperature is always higher than the dry bulb temperature. | False |
| Solvent | Substance that dissolves solutes |
| Solute | Substance dissolved in a solvent |
| Solution | Composition of solute and solvent |
| Colligative properties of solutions | Properties that depend on the number of molecule present (not nature or size) eg. vapor pressure, boiling point, osmotic pressure |
| Unsaturated solution | A liquid that holds less solute than possible |
| Saturated solution | A liquid that holds the amount of solute is can dissolve at a given temperature |
| Supersaturated solution | A liquid that holds more solute than it can theoretically dissolve at a given temperature |
| T or F: For every mole of nonvolatile solute in 1000g of solvent, the boiling point is raised 0.52 degrees and the freezing point is lowered 1.86 degrees | True |
| Molality | moles/kg |
| Molarity | moles/L |
| T or F: Freezing point is not affected by elevation. | True |
| T or F: For every 960 ft above sea level, the boiling point decreases by 1 degree | True |
| Bound water | Cannot be removed by normal drying; no longer a solvent; no appreciable vapor pressure, only freezes at very low temperatures, needs high vacuum to be removed from tissues |
| Water activity | Means of determining microbial stability in food; related to the rate of some chemical reactions in food; aw= sample vapor pressure/water vapor pressure |
| Vapor pressure | Pressure that vaporized molecules product over the surface of a liquid |
| Water isotherm | Relationship between water content and equilibrium humidity displayed as curve |
| Hystersis | The time-bases dependence of a system's output on a present and past inputs |
| What is the aw value for bacteria (permitting growth) | 0.91 |
| T or F: Water activity is one means of determining microbial stability in food. | True |
| Temperature of glass transition (Tg) | The temperature at which a substance changes from a rubbery to a glassy state (eg. hard candy manufacture) |
| Water hardness | mg/L of calcium carbonate |
| Temporary hard water | Contains calcium bicarbonate or magnesium bicarbonate |
| Permanent hard water | Contains calcium sulfate or magnesium sulfate |
| Softened water | Water that has had calcium and magnesium ions removed |
| Distilled water | Has most impurities removed by boiling and condensing the stream |
| Deionized water | Impurities reduced by ion exchange resins and activate carbon filters |
| Name the steps in softening hard water | 1. Boil 2. Add reactive compounds (forms insoluble caronate salts) 3. Use ion exhange (removes Ca or Mg in exchange for Na or H) |
| T or F: Water hardness is measured by the amount of sodium chloride the water contains. | False |
| What does milk include? | Emulsified fat globules, casein micelles/proteins, lactose and salts |
| Total milk solid | All components of milk except water |
| Milk solids/Nonfat milk solids | All components of milk solids except fat |
| What is the composition of milk? | Fat (3.5-3.7%), protein (3.5%), carbs - lactose (5%), ash (0.7%), water (87%) |
| Milk is a rich source of _________ and contains 95% _______. | Conjugated linolenic acid fat, triglycerides |
| What are the major proteins in milk? | Caseins, whey proteins |
| Casein | Makes up 80% of protein in milk, exists as micelles, collodal dispersion; alpha, beta, kappa, and gamma |
| Whey | Remaining liquid after curds are precipitated during cheese making; contains water, whey proteins (soluble/easily denatured), water soluble vitamins, lactose, minerals |
| Name the milk enzymes. | Alkaline phosphatase (used to check pasteurization), lipases (inacivated by pasteurization), proteases |
| Milk is a good source of _____, ______, and ______. | Phosphorus, magnesium, niacin |
| Milk is an excellent source of _____ and _____. | Calcium, riboflavin |
| What characteristics of the cow affect milk composition? | Genetics/breed, age, season, storage of lactation, feeding, period of time between milking, physiological condition of cow |
| What are the steps in milk production? | 1. Milking; 2. Cooling and storage; 3. Tank transportation to the processing plant; 4. Separation of cream and skim; 5. Recombination to make 1%, 2%, etc; 6. Homogenization; 7. Pasteurization; 8. Packaging; 9. Refrigerated storage/distribution |
| Homogenization | Reduction of milk fat globule size to eliminate creaming; milk forced through small openings under pressure |
| Milk fat globule is the form of _____ fat in milk. | emulsified |
| Pasteurization can be performed at: | Low temp longer time, high temp shorter time, ultra high temp |
| How do we test for proper pasteurization? | Alkaline phosphatase should be inactivated |
| T or F: High fat products yield less reactivated phosphatase. | False |
| Name other routine milk tests: | Added water (check freezing point), antibiotics, bacteria, somatic cell counts |
| What do high counts of somatic cells in milk indicate? | Some type of illness and immune response in cow |
| What effect does heat have on each of the following: pathogenic bacteria, enzymes, proteins, flavor? | Pathogens - destroyed Enzymes - inactivated Proteins - denatured Flavor - loss or cooked flavor induced at >74 degrees |
| When milk is heated, a "skin" forms on the surface. What causes this and how can it be controlled? | Water evaporates from the surface, concentrating protein which entraps fat and calcium. Cover the container or place a foam on the milk surface |
| Explain the effect of the following treatments on milk: freezing, exposure to direct sunlight, lipase activity of bacteria, left at room temp for 12 hours | Freezing - can be done for 3-4 months; casein has limited stability Exposure to direct sunlight - oxidative rancidity Lipase activity of bacteria - hydrolytic rancidity Left at room temp - lactic acid bacteria produce acid > souring |
| How is milk treated for lactose intolerant people? | Treated with enzyme lactase to hydrolyze lactose to glucose and galactose |
| Cream | an oil in water emulsion that separates from whole milk upon standing (~30% fat) |
| What does churning cream do to make butter? | Disrupts fat globule membrane and causes fats to coalesce. Flavor compounds: lactones and butyric acid |
| What microorganisms are used to make yogurt? | S. thermophilus and L. bulgaricus |
| What microorganisms is kefir fermented with? | L. Caucasus, S. kefir, T. kefir - contains 1% alcohol |
| Filled milk | Milk fat is replaced with fats from other sources other than milk |
| Imitation milk | Both milk fat and milk proteins are replaces with less expensive ingredients |
| Non-fat dry milk | Spray-dried processed skim milk |
| Instant non-fat dry milk | Wetted, agglomerated and re-dried non-fat dry milk (flavor is better) |
| Evaporated milk | Milk heated to remove 60% of water, then homogenized and canned; 8% milk fat, 26% milk solids |
| Sweetened condensed milk | Milk is pasteurized and 50% of water is removed; 44% sucrose added as a preservative; 8.5% milk fat, 28% milk solids |
| Cheese characteristics are affected by: | types of microorganisms, temperature at ripening, humidity, length of ripening |
| Overrun | Increase in volume of ice cream due to air |
| overrun equation | overrun = [volume of ice cream - volume of mix]/volume of mix |
| The Jungle by Upton Sinclair (Chicago) prompted the creation of _______. | The Food Safety and Inspection Service |
| Name the three types of muscle. | Striated (skeletal), smooth (viceral/organs), cardiac (viceral) |
| Myofibril | muscle bundles composed of actin and myosin |
| Stromal | Watery connective tissue proteins in collagen, elastin, and reticulin |
| Sarcoplasmic | Pigments and enzymes |
| Endomysium | Thin connective sheath that covers actin and myosin |
| Give the hierarchy of muscle. | myofibil>fiber>bundle of fibers>muscle |
| The thin filament is _____ and the thick filament is _______. | Actin, myosin |
| The sarcoplasmic reticulum forms ____ on either side of the T-tubules forming a _______. | Terminal cisternae, triad |
| T or F: The sarcoplasmic reticulum stores Ca++ when the muscle is not contracting. | True |
| Name the major steps of muscle contraction (1-5). | 1. Message from nerve 2. Nerve terminal releases acetyl choline 3. Acetyl choline diffuses to muscle cell membrane and binds receptors 4. Receptors cause cell membrane to "leak" - Na out K in 5. Membrane depolarization spreads across T-tubules |
| Name the major steps of muscle contraction (6-9). | 6. T tubules cause Ca release on sarcoplasmic reticulum 7. Troponin changes shape and moves tropomyosin > myosin binds actin 8. Myosin heads move and muscle shortens (release ADP) 9. Ca is pumped back into the sarcoplasmic reticulum and muscle relaxes |
| How does electrical stimulation increase tenderness? | Muscles contract and use up ATP > acceleration of glycolysis; proteolytic enzymes are released |
| What is the pI of meat? | ~5.2 |
| What is used to increase the water holding capacity of meat? | Phosphate (alkaline) > increases negative charges of the protein so that water can bind |
| What happens when post-mortem meat is left to sit for too long? | Rapid pH drop > fibrous and dry meat, protein denaturation |
| PSE | pale, soft, exudative in ~45 minutes |
| DFD | dry, fibrous, dark in 1-2 hours |
| What is the composition of meat? | water, protein, fat, carbs, minerals |
| Stroml proteins | insoluble, holds organs together, contribute to poor meat quality (eg. collagen and elastin) |
| T or F: Connective tissue (collagen, tendons, strap meat) increase the tenderness of the meat product. | False |
| Name the sarcoplasmic proteins | Enzymes, mitochondrial proteins, myoglobin |
| Myoglobin | heme ring with iron as the core - attached to globin protein by histidine |
| What are the differences between hemoglobin and myoglobin? | Hemoglobin carries O2 to blood, myoglobin stores O2 in muscles; myoglobin has higher affinity for oxygen |
| Reduced myoglobin will give ______ meat, oxymyoglobin will give ______ meat, and metmyoglobin will give ____ meat. | purple, bright red, brown |
| T or F: Myofibrillar proteins contain all essential amino acids and have excellent digestibility. | True |
| How can lipid oxidation of meat be prevented? | Freeze meat rapidly after slaughter, bind to phosphates (oxidative catalyts), bind to antioxidants (BHA. BHT, TBHQ, tocopherols) |
| T or F: Quality grades are not given for pork and are voluntary. | True |
| Humane Slaughter Act | Animals must be unconcious before exsanguination; approved stunning methods include captive bolt, electric shock, carbon dioxide, and gunshot |
| T or F: In kosher slaughter, a rabbit cuts the meat after stunning the animal. | False |
| T or F: In Halal slaughter, the meat must not come in contact with pork. | True |
| Why is nitrite added in meat curing/smoking? | To inhibit C. botulinum spores. |
| What are the ingredients used in curing/smoking? | Salt, sugar, nitrite, vitamin C (speeds color change), alkaline phosphates (decreases shrinkage), spices, water |
| What are the factors for color after curing/smoking? | myoglobin content, pH, amount/uniformity of nitrite, microbiological condition, post-processing exposure to light/oxygen |
| What are the ingredients in sausage? | Meat, water, salt (preservation, flavor, solubilize actin/myosin), nitrite ascorbate and erythrobate (convert metmyoglobin and nitrite to myoglobin and NO), sugar, antioxidants (prevent fat oxidation), phosphates, GDL, mold inhibitors, MSG, sodium lactate |
| Meat emulsion | Protein emulsifying agent in which protein unfolds and hydrophobic parts point towards lipid and hydrophilic part towards continuous phase - myosin is best emulsifying protein, collagen is worst |
| What can cause unstable emulsion? | Over chopped meat, heating, too much collagen |
| What pathogens are of concern in meat? | Salmonella, E. coli, C. jejuni, C. botulinuim, S. aureus, etc. |
| Why is the suggested minimum temp of whole muscle cuts lower than ground meat? | Pathogens are on the surface in whole cuts, but mixed in in ground meat. |
| Poultry | Domesticated birds kept for meat or eggs; include chicken, turkey, ducks, quail, etc. |
| Rock Cornish game hen | 5-7 weeks old turkey, up to 2lbs |
| Broiler/Fryer | 9-12 weeks old chicken, 2-2.5 lbs |
| Roaster | 3-5 months old chicken, 3-5 lbs |
| Capon | <8 months old chicken, male, 4-8 lbs |
| Hen | ~12 months old chicken, female, 4-8 lbs |
| Fryer (turkey) | <16 weeks old turkey, 4-8 lbs |
| Young hen/Tom | 5-7 months old turkey, 8-14 lbs |
| Yearling/Tom | <15 months old turkey |
| Mature or old turkey | >15 months old turkey |
| Antemortem inspection | check bird for illness of injury |
| Post mortem inspection | After stunning, bleeding, scalding, plucking, and evisceration |
| What factors are considered when grading poultry? | Condition or wholesomeness (no feces, feathers, bruises, etc.), class (age/sex), quality (# defects, amount of meat, color) |
| What are the Grade A standards for chicken? | Free of deformities, well fleshed, free of feathers/feces, max diameter of cuts/tears = no more than 1.5 inches, no borken or missing joints (except wing tips/tail), little discoloration |
| How many birds (chicken and turkey) can be found in a grow-out house? | Chicken - 25,000/house Turkey - 5,000/house |
| What essential amino acids are poultry fed? | Lysine, methionine |
| Free Range | traditional house with access to outdoors |
| Pastured/pasture raised | Raised outdoors using movable enclosures |
| T or F: No hormones have been approved by the USDA for use in turkeys and chickens | True |
| Evisceration | cutting of the abdominal cavity and removing of the entrails |
| Scalding | dipping the poultry carcass into hot water for the purpose of removing the cuticle (outer layer of skin) |
| When is the tenderness of poultry optimal? | 2-2.5 hours after post-mortem, where there is a pH drop |
| Bologna and wieners | Emulsion of meat and fat which is cooked to form a gelled product |
| Giblets | edible internal parts of the poultry including liver, gizzard, and heart |
| How is oxidative rancidity measured for poultry? | TBA (TBARS), head-space GC - TBA > 1 > rejected |
| PSE | Pale Soft Exudates; protein denaturation due to a combination of high temp and fast pH drop after death; caused by rough handling, excitement, incomplete stun/kill, or genetic reasons |
| What are some poultry quality concerns? | Bone residue, susceptibility to oxidation, chilling method can affect, susceptibility to microbial growth |
| Water can absorb _____ from the air to become acidic. | carbon dioxide |
| Water may be adjusted to become _____ to minimize corrosion of pipes and deposition of carbonates. | alkaline |
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