Sampling Flashcards
Ideal sample
Should be ideal in all of the intrinsic properties with the bulk of the material
Population
Entire lot or production
Sampling
Process of taking samples
Sample increment
Individual portion of material collected by a single operation from parts of a lot
How often you take samples
Samples
Small proportions used for the analysis
Lab samples
Fraction of the sample that is used in the final laboratory analysis
Sampling Steps
Identify the population
Select and obtain gross samples
Reduce the gross samples to a laboratory size sample for analysis
Why sample
100% confidence = 100% of the sample
Nothing left to sell
Expensive, time consuming destructive
Not practical
Random sample
Bulk material divided into a # of segments
Segments selected according to a predetermined pattern
Systematic sample
Collected to test changes in composition with
Time
Temp
Location
Treatment
Representative sample
Only from truly homogenous materials
Composite samples
Obtained from special techniques designed to produce representative samples
Combine samples together to get representative sample
Non probability sampling
Probability of including any specific portion is not equal
Select the sample deliberately
Judgment sampling
At the discretion of the sampler
Gives you the info you need
Convenience sampling
Ease of sampling is the key factor
Restricted sampling
Entire population is not accessible
Take the samples you can access
Quota sampling
Division of a lot of groups representing various categories, samples are taken from each group
Manual sampling
Person taking the sample attempts to take a random sample to avoid human bias
Continuous sampling
Performed mechanical
Less prone to bias
Measure as it comes out of the process
Purpose of sampling
Nutritional labeling
Detect contaminants
Statistical process control
Accept or reject raw materials
Release of lots of finished products
Micro safety
Sampling plan contains
Goals
Factors to be measured
Sampling point
Sampling procedure
Frequency and size
Personnel
Preservation
Unreliable data obtained by
Poor sampling techniques
Sample degradation
Mislabeling of samples
Grinding dry materials
Mortar and pestle
Mills
Mechanical grinding device
Screens control particle size
Grinding moist materials
Grinding might cause moisture loss
Bowl cutters, meat mincers, tissue grinders
Enzymatic treatments
Cellulases
Proteases
Carbohydrases
Disintegrate materials
Chemical treatments
Disintegrate or extract
Urea
Pyridine
Phenol
Acid
Enzymatic inactivation
Heat denaturation
Freezer storage
Change the pH
Salt out
Lipid ox protection
Protect unsaturated lipids
More stable when frozen
Antioxidants
Protect from light
Microbial growth and contamination
Freezing
Drying
Preservatives
Storage time and conditions
Aseptic technique
