Different analytical techniques for assessing soybean meal quality: A review

High concentration of protein with balanced essential amino acid profile, low fibre and better vitamin as well as mineral contents makes soybean meal (SBM) the most suitable protein source for simple stomached animals. Trypsin inhibitor in association with many otheranti nutritional factors (ANFs) limits the use of raw soya bean in poultry. Traditional hot processing of soy bean to extract oil and to produce SBM, are quite effective in deactivation of major ANFs. However, over processing has adverse effect on protein digestibility especially the lysine availability. To have maximum benefit of SBM in biological system for conversion into meat and eggs, its quality must not be compromised at any cost. In order to weigh up SBM quality a number of physical tests and laboratory procedures have been evolved. The most widely accepted and used chemical methods are potassium hodroxide (KOH) solubility test and urease activity test. The established permissible range of these two parmetersis 75–90% and 0.05–0.3, respectively for good quality SBM. Protein dispersibilityindex (PDI) is the third most important assay, which has a permissible range of 40–45% for best quality SBM. As a more sensitive and rapid quality assay AMINORED is acquiring importance in scientific as well as commercial forum. The colour, bulk density and protein contents should also be taken care of.