FSTC201 EXAM 2 practice PDF

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EXAM #3 Practice Test: 1. The procedure to heat sealed cans to destroy C. botulinum spores is achieved using the equivalent of 121o C for 7 minutes. This is equivalent to ___ F. (a) 195(d) 300 (b) 350(e) 250 (c) 225 2. Which mechanisms are responsible for heat transfer in foods? (a) irradiation, high pressure, canning (b) conduction, convection, irradiation (c) conching, tempering, pressing (d) grinding, melting, evaporation (e) radiation, conduction, convection 3. Which statement is incorrect? (a) The aglycone of an anthocyanin is called the anthocyanidin. (b) Hydrolysis of a glucoside produces an aglycone, sugar, and water. (c) Aglycone joins to a sugar by a glycosidic bond. (d) Delphinidin is an example of an anthocyanidin. (e) The aglycone of a betanidin is called betanin. 4. Freeze-dried meats have virtually all of their moisture removed (as ice) via sublimation. (a) True (b) False 5. In egg processing, when a fine stream of liquid egg is dried very quickly in midair by heat, this is called plate drying. (a) True (b) False 6. In dairy product processing, a standard method involves HTST processing, which refers to high temperature short time. (a) True (b) False 7. A bacteriostatic agent kills microorganisms, such as foodborne bacteria. (a) True (b) False 8. (a) (b) (c) (d) (e)

Blanching deactivates PPO enzyme. is not the same as pasteurization. is a type of thermal processing. is a processing step often applied to fruits and vegetables. all of these.

9. Which is the food industry unit operation associated with creating extruded cereals? (a) separating (b) evaporation. (c) disintegrating. (d) pumping (e) forming. 10. What is meant by tempering? (a) fats like cocoa butter that exist in more than one crystal form (b) selecting the a (alpha) crystal form of cocoa butter during melting and cooling

(c) selecting the B’ (beta prime) crystal form of cocoa butter during melting and cooling (d) temperature manipulation so that cocoa butter will solidify into the desired, stable (B) crystal form (e) keeping the temperature high enough that all of the crystal forms remain melted 11. In the manufacture of process cheese, what is true? (a) starter cheese is a natural cheese (b) the casein in the starter is not effectively functioning as an emulsifier (c) there is an ion exchange between the emulsifying salt and the Ca in calcium caseinate (d) choices (a) and (c) (e) choices (a), (b), and (c)** 12. Which processing step is regulated as a food additive? (a) canning (d) freezing (b) irradiation (e) pasteurization (c) extruding 13. D values written as D121 indicate (a) the specific temperature (121) required to kill 90% of a population of microorganisms (b) specific time required to kill 90% of a population of microorganisms at 121oC (c) that thermophilic spores are present (d) that mesophilic spores are present (e) none of these 14. The goal of retorting is … (a) to destroy Clostridium botulinum (b) to achieve commercial sterility (c) to destroy all microorganisms (d) both (a) and (b) (e) (a), (b), and (c) 15. _____________ contains numerous ______ crystal forms, which is referred to as _________ . (a) cocoa butter; liquid; crystallization (b) cocoa butter; sugar; crystallization (c) cocoa butter; fat; polymorphism (d) fat; beta; polymorphism (e) lard; ice; freezing 16. The irradiation D value for C. botulinum is 3.5, while for E. coli the D value is 0.2 – what should you conclude? (a) C. botulinum is more heat resistant (b) 3.5 is the specific time required to kill 90% of E. coli at 121oC (c) E. coli is more resistant to irradiation processing (d) 90% of C. botulinum are killed at a dose of 3.5 kGy (e) irradiation is ineffective against these microorganisms 17. A medium dose of irradiation (for food applications) (a) is called radicidation (b) is between 0 and 1.0 kGy (c) is between 1 and 10 kGy

(d) is over 10 kGy (e) is called radapperization 18. In which phase of bacterial growth does the number of new living cells greatly exceed the number of dead and dying cells? (a) lag (b) log (c) lug (d) decline (e) incline 19. Look at “situation 4” (pH 5.5, 14oC, and 5% NaCl), and recall hurdle technology. What is observed?

(a) situation 4 shows 3 failed hurdles. (b) the temperature hurdle is a successful hurdle. (c) situation 4 shows 3 combined hurdles. (d) the pH hurdle alone stops the microorganism. (e) 5% NaCl alone stops the microorganism.

20. Look at the plot that shows spore concentrations versus processing parameters, and the points A, B, C, D, and E. Which is false? (a) As spore suspension concentration increases, kill time must increase (A vs. E) (b) A sample containing 104 spores/mL survives the processing time/temp combination represented by point C (c) A sample containing 105 spores/mL survives processing time/temp combinations represented by points A, B, and C (d) Processing at 230oF for 30 min (B) would be effective eliminating spores at levels of 103 or less (e) As spore suspension concentration increases, kill temp must increase (B vs.C)

21. This statement is the correct interpretation of the plot below: The log number of viable cells is reached sooner with the curve on the left (the solid line), and is related to water activity. (a) True (b) False

22. On a bacterial survival plot, when one log cycle moves from 108 organisms to 107, the number 107 means 1,000,000 organisms. (a) True (b) False

23. Which statement is FALSE? (a) Cocoa can be a significant source of antioxidants. (b) ORAC stands for Oxygen Radical Absorbance Content. (c) The ORAC for cocoa is 28,000 ORAC units per 100 grams of unprocessed raw cacao. (c) Research has shown a link between cocoa consumption and improved cardiovascular health. (e) Improved heart health when cocoa is in the diet is believed to be due to cocoa’s antioxidant content, especially the epicatechins. 24. Fatty acids have the general structure CH3(CH2)nCOOH. (a) True (b) False 25. Which statement is FALSE? (a) Fatty acids that contain only single bonds between carbon atoms are unsaturated fatty acids. (b) Saturated means that each carbon pair (C-C), in addition to bonding to each other, is bonded to four hydrogen atoms (two each). (c) Unsaturated fats are triglycerides that contain glycerol and between one and three unsaturated fatty acids. (d) An unsaturated fatty acid contains one or more double bond (C=C) between adjacent carbon atoms.

(e) Each double-bonded carbon pair, in addition to bonding to each other, is bonded to only two hydrogen atoms (one each). 26. In the oxidation of food lipids, oxygen molecules react with the double bonds of unsaturated fatty acids. (a) True (b) False 27. The quantity of hydroperoxide in a fat sample can be measured and is called the peroxide value (PV), which is used as a predictor of the level of oxidation in a fat. (a) True (b) False 28. Lipid oxidation or Iipoxidation consists of a sequence of steps, including initiation, propagation, and termination. (a) True (b) False 29. Look at this molecule and select the best answer: Which choice is TRUE? COOH – (CH2)4 – CH=CH – (CH2) – CH=CH – (CH2) – CH=CH – (CH2) – CH=CH – (CH2) – CH3 (a) This molecule is a saturated fatty acid. (b) This molecule is a C16 fatty acid. (c) This molecule is C18:2. (d) This molecule is a trans fatty acid. (e) This molecule is susceptible to oxidation. 30. ROOH is a ___________________, one of the major initial oxidation products that decompose to form compounds responsible for off-flavors and odor. (a) free radical (b) unsaturated radical (c) hydroperoxide (d) secondary aldehyde (e) secondary alcohol 31. The rate of oxidation of fatty acids increases with the degree of unsaturation. (a) True (b) False 32. What is shown by: R· + O2 --> ROO· (a) UFA free radicals form during INITIATION that react with oxygen to produce a peroxyl free radical. (b) peroxyl free radical reacts with nearby UFA to generate a new UFA free radical. (c) the propagation step in lipid oxidation (d) the termination step in lipid oxidation (e) the effect of an antioxidant in lipid oxidation 33. Which statement is FALSE? (a) triacylglycerols (TGs) are formed from the combining of glycerol plus 3 fatty acids

(b) hydrocarbon chain portions of fatty acids are represented by -CH2(c) the configuration around a C=C double bond can be either cis or trans (d) stearic acid (C18:2) has a lower melting point than linoleic acid (C18:0) (e) SCFA (short chain fatty acids) usually have lower melting points than LCFA 34. Which statement concerning casein molecules at the pI is TRUE? (a) casein molecules become stabilized (b) casein molecules associate with each other (c) the pI for casein is a pH of 7.0, which causes casein denaturation (d) casein molecules are repelled from each other (e) the overall (net) charge on the surface of each casein molecule is positive 35. At the pI of casein: (a) the # of OH- ions > the # H+ ions (d) protein:water associations are favored (b) casein solubility increases (e) the # of H+ ions > the # OH- ions (c) protein:protein associations are favored 36. According to the AH,B theory of sweetness, there is an attraction for the proton (+ charge) of the AH region of the sweet tastant molecule (“glycophore”) and the unbounded electrons (charge) of the B region of the receptor molecule in the tongue. (a) True (b) False 37. What is the arrow directly pointing to?

H C N R H

....

H N C O

O H C R

C

(a) carboxyl group (b) hydrogen bond (c) peptide bond

....

(d) glycosidic bond (e) dipeptide

38. In bacterial (cell) growth, what is the difference between “lag” and “log”? (a) there is no difference (b) “lag” has to do with cell growth, while “log” has to do with cell death (c) in “lag”, the number of dying cells exceeds the number of living cells (d) “lag” represents an earlier stage compared to “log” (e) the population of cells during “lag” > the population of cells during “log”

39. In cocoa bean processing, what does tempering achieve ?

(a) polymorphism (b) esterification of lard (c) destruction of all microorganisms (d) total melting of all polyunsaturates (e) selection of the proper crystal form 40. What is the Hunter L, a, b used for? (a) to measure food texture (b) to measure food color (c) to measure “aftertaste” values of food (d) to measure the brain response to food (e) to measure viscosity values of food 41. What does this show? organic acid + organic alcohol à artificial banana flavor + water (a) hyperventilation (d) perspiration (b) calculation (e) ester formation (c) emulsification

42. What do you know about these three substances: S-S-S, S-O-S, and S-O-P ? (a) they are distress signals used by the US Coast Guard (b) they represent tristearin, stearic-oleic-stearic, and stearic-oleic-palmitic (c) they are three different triglycerides that would have the same MPs (d) they are three glutamine peptides used to provide fast energy (e) they are fatty acids 43. What is an example of how to apply the Hurdle concept or principle? (a) heating meat to an internal temperature of 140o F (b) applying an irradiation dose of 2.5 kGy to ground beef and freezing it (c) lowering the pH of a food product to 2.5 units (d) adding salt at a concentration of 15% (e) heating meat to an internal temperature of 160o F 44. Which is NOT one of the factors known to affect microbial growth in foods? (a) increasing the acidity (b) changing the oxygen content in a food package (c) adding 1% cis-unsaturated fatty acid (d) thermal processing (e) irradiation 45. True or False: In a can heated via conduction, the cold point is lower than the center due to density differences. (a) True (b) False 46. We discussed collagen and gelatin in class; which of the following is unique to GELATIN? (a) contains glycine, proline, and hydroxyproline amino acids

(b) contains tropocollagen (c) contributes significantly to meat toughness (d) is broken down by collagenase enzyme but not other proteases (e) is derived from connective tissue 47. Myglobin- pigment that determines There will probably be some additional questions on the actual exam regarding food color (especially look over myoglobin, chlorophyll, and anthocyanins)

and

*** DON’T FORGET THAT I GAVE A HINT IN CLASS that you ALSO need to do the reading in chapter 8 regarding the specific processing examples (Frankfurters/Cheese/Breakfast Cereal/Canola Oil/Orange Juice/Tofu/Chocolate) – with an eye for two details in particular: 1. What unit operation(s) are important in the processing and manufacture of the item? 1. 2. What if any “kill step” is used in order to address food spoilage by microorganisms, to extend product shelf life? HAPPY STUDYING and GOOD LUCK on FRIDAY!...