Proximate Analyses
These Association of Official Analytical Chemists, International (AOAC), and peer-reviewed Journal of the AOAC, Int., and other Official and research procedures are specifically designed for the analysis of feeds, plant tissue, cereals, raw and processed foods, solutions, media, and waste products where sample amounts are suitable for each test requested.
The etymology of 'proximate' is the Latin word proximatus, meaning 'to come near' or 'close'. Hence, many of the proximate analyses are prefaced by the word 'crude', i.e., crude protein and crude fat, which also indicates that the several of the methods are indirect. An example of this is the measurement of a samples total nitrogen content (i.e., N2) which is then converted to a crude protein value.
A full range of proximate analyses and related fiber and protein procedures are listed below. Please visit the other navigation sites for further carbohydrate, lipid and mineral offerings.
Feeds, Grains and Foods
- Proximate Analyses Package
- Crude Protein (LECO), Crude Fat, Moisture, Ash, and Crude Fiber
- Crude Protein (Kjeldahl), Crude Fat, Moisture, Ash, and Crude Fiber
- Crude Protein or Total Nitrogen
- Combustion Analysis (LECO)
- Kjeldahl
- Ash Determination
- Acid Insoluble Ash
- Crude Fat Soxhlet
- Soxhlet: by Ether Extraction or Hexane
- by Acid Hydrolysis
- Fat by Folch Extraction
- by chloroform:methanol:water
- Fat by Acid Hydrolysis
- Soap, total fat requires acidification prior to fat extraction.
- Other Fats (see Lipids, Fats and Oils)
- Crude Fiber
- Peroxide Value requires fat extraction in addition to method. (see reference section)
- Moisture (vacuum oven, also, freeze-drying is available)
- Starch
- Nitrogen Free Extract *
- Carbohydrates, by difference *
- Gross Calories (protein, fat, carbohydrate), calculation *
*methods require proximate analysis
Crude Fiber and Components
- Crude Fiber (CF)
- Acid Detergent Fiber (ADF)
- Neutral Detergent Fiber (NDF)
- Cellulose (Cel) requires Acid Detergent Fiber (ADF)
- Hemicellulose calculation requires NDF and ADF
- Lignin requires Cellulose and Acid Detergent Fiber (ADF)
- Total Dietary Fiber (TDF) in Foods * >> NDF analyses <<
- Total, Soluble and Insoluble Dietary Fiber in Foods
Protein Analyses - Miscellaneous
- Pepsin Digestibility of Animal Protein
- 0.2% pepsin as per AOAC - includes crude protein determination.
- Protein Dispersibility Index (PDI) requires a proximate crude protein analysis in addition to method.
- Nitrogen Solubility Index (NSI)
- Protein Solubility from Soybean Meal (KOH method) requires a proximate crude protein analysis in addition to method.
- Trypsin Inhibitor Activity - Soybean (TIU/g)
- Urease Activity (soybean meals, flour, millfeeds)