AOCS is the leading provider of methods and recommended practices critical to running a quality lab in the fats, oils and plant-protein industries, and recently approved a new method, Method Ba 12a-2020, for assaying trypsin inhibitor activity in plant-based food materials including soybeans, pulses, beans, cereals and their processed products.
|Crystallographic structure of a Kunitz-type |
trypsin inhibitor from Erythrina caffra seeds.
AOCS has had an official Method for measuring trypsin inhibitor activity since 1975. As part of the ongoing process of method revision, a new Method Ba 12a-2020 has recently been approved by the AOCS Uniform Methods Committee. Keshun Liu, a Research Chemist with United States Department of Agriculture, Agricultural Research Service (USDA-ARS), has led this effort.
“The new method is easier to learn, requires smaller amounts of reagents and gives results with greater precision,” he says.
Method Ba 12a-2020 assesses inhibitor activity from the increase in light absorbance at 410 nm using Nα‐benzoyl‐DL‐arginine‐ρ‐nitroanilide as a synthetic trypsin substrate. It has an expanded scope, addressing the need for analytical methods for non-soy plant proteins. It also provides results using more meaningful units of measurement.
“Using AOCS Ba 12a-2020 analysts can now express results as the amount of trypsin inhibited, instead of using an arbitrary unit,” says Liu. “The new unit is standardized against a reference trypsin with a fixed value of specific enzyme activity. If other methods adapt this new concept of standardization against the same reference trypsin, results will become comparable among reports.”
“The creation and validation of methods that encourage comparison of measurements from different laboratories is central to AOCS’s mission,” says Scott Bloomer, Technical Services Director at AOCS. “The genesis of our society in 1909 was a collaborative effort among cottonseed producers to standardize analytical results.”