Ch 19/20 Study

Front 1

Indicatewhy the FDA has established DALs.

Back 1

- Reflect current max levels for natural or unavoidable defects in food for humans who use that present no health hazard

- Reflects max levels considered unavoidable under good manufacturing practice

- It's virtually impossible to have plant and animal materials free of various forms of contaminants as materials are stored, handled and transported

Front 2

Explainwhy practicing cGMPs has no impact on DALs.

Back 2

Because DALs are established for unavoidable filth that will occur irrespective of what we do, it is inherent property of our harvesting and processing foods

Front 3

List three majorreasons for conducting analysis for extraneous matter in foods.

Back 3

- To ensure protection of consuming public from harmful or filthy food products

- To meet regulatory requirements of the FD&C

- To comply with defect action levels

Front 4

What two resources provide methods forseparating extraneous matter from cereal grains and their products?

Back 4

AOAC

AACC

Front 5

There are several basic principlesinvolved in separating (isolating) extraneous matter from foods. List five of these principles and give anexample of each principle.

Back 5

Density

- Sedimentation method to measure heavy filth in shelled nuts

Affinity for oleophilic solvents

- Cracking flotation method to measure insect infestation of wheat

Particle size

- Sieving method to remove foreign matter in spices and condiments

Diagnostic characteristics for identification of filth

- Characteristics of molds, insect fragments grain

Chemical identification of contaminants

- Animal urine and excrement

Front 6

Briefly describe the major constraint(s)to currently accepted methods for analyses of extraneous matter in foods.

Back 6

- Methods can be quite subjective; requires experienced analyst

- Multiple steps in procedures makes being quantitative difficult

- Fragment counts don't reflect total contaminant biomass present

Front 7

Explain how some of the more recent analytical techniques can assist in identifying sources of extraneous matter in foods

Back 7

-X ray is used to inspect wheat for internal infestation

- Uric acid measures bird or insect contamination

- Microscopy techniques can be used to determine the nature of metals present in foods

Front 8

BODPrinciple -

Back 8

- Measure amount of O2 required by MOs to oxidize biodegradable organic constituents present in water and waste

- Based on direct relationship between concentration of organic matter and amount of O2 used to oxidize the pollutants and inorganic nitrogenous compounds

Front 9

BODProcedure-

Back 9

- Put water sample that has been seeded w/ appropriate MOs in air tight BOD bottle

- Measure initial dissolved oxygen immediately

- Incubate sample at 20 C for 5 days, measure oxygen again

Front 10

BOD what it stands for

Back 10

Biochemical Oxygen Demand

Front 11

CODPrinciple -

Back 11

- Organic compounds are destroyed by refluxing in strong acid solution w/ a known quantity of an oxidized agent

- Excess potassium dicromate that remains after digestion of organic matter is measured

- Amount of organic matter that is chemically oxidizable is directly proportional to amount of potassium dichromate consumed

Front 12

CODProcedure -

Back 12

- Reflux known amount of water or wastewater at high temp for 2 hours, w/ known amounts of potassium dichromate and sulfuric acid

- Titrate excess potassium dichromate w/ standard ferrous ammounium sulfate solution using orthophenanthroline ferrous complex as an indicator

- Caculate COD value w/ equation given

Front 13

COD what it stands for

Back 13

Chemical Oxygen Demand

Front 14

Inwhat case would they be instructed to use mercuric sulfate in the COD assay?

Back 14

Use mercuric sulfate if hig chloride levels in sample

Front 15

BODAdvantages -

Back 15

-Less expensive

-No interference

- Truly measured dissolved oxygen lost

Front 16

BOD Disadvantages -

Back 16

- Slower

- Gives low values if poor seed material

- Lower precision

Front 17

Higher or lower COD: Poor seed material in BOD test

Back 17

COD higher

Front 18

Higher or lower COD: Samplecontains toxic materials

Back 18

COD higher

Front 19

Higher or lower COD: Samplehigh in aromatics and nitrogenous compounds

Back 19

BOD higher

Front 20

Higher or lower COD: Samplehigh in nitrites and ferrous iron

Back 20

COD higher

Front 21

Higher or lower COD: Samplehigh in cellulose and lignin

Back 21

COD higher

Front 22

COD Advantages

Back 22

- Faster

- Better precision

Front 23

COD Disadvantages

Back 23

- More expensive

- Not truly measuring dissolved oxygen

- Interference from some compounds