TY - JOUR
T1 - Continuous method to determine the trypsin inhibitor activity in soybean flour
AU - Coscueta, Ezequiel R.
AU - Pintado, Manuela E.
AU - Picó, Guillermo A.
AU - Knobel, Gastón
AU - Boschetti, Carlos E.
AU - Malpiedi, Luciana Pellegrini
AU - Nerli, Bibiana B.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - The determination of trypsin inhibitor (TI) activity is of importance to evaluate the nutritional value of soybean flours. An analytical method, which involves a continuous spectrophotometric rate determination for trypsin activity against the substrate N-benzoyl-DL-arginine p-nitroanilide, is proposed as an alternative to the standard discontinuous assay. Stopping the reaction with acetic acid and a centrifugation/filtration step to decrease turbidity are not required, thus reducing costs and sample preparation time. The TI activity of different flour samples, determined by both assays, demonstrated to be statistically comparable, irrespective of the TI concentration level. The coefficients of variation of the novel method did not exceed 8% at any concentration level. The curves of progress reaction showed a non-linear behavior in samples without TI. A reduction of incubation time from 10 min to 2 min increased the method sensitivity and extended its linear range. A more economical, faster and simpler assay was developed.
AB - The determination of trypsin inhibitor (TI) activity is of importance to evaluate the nutritional value of soybean flours. An analytical method, which involves a continuous spectrophotometric rate determination for trypsin activity against the substrate N-benzoyl-DL-arginine p-nitroanilide, is proposed as an alternative to the standard discontinuous assay. Stopping the reaction with acetic acid and a centrifugation/filtration step to decrease turbidity are not required, thus reducing costs and sample preparation time. The TI activity of different flour samples, determined by both assays, demonstrated to be statistically comparable, irrespective of the TI concentration level. The coefficients of variation of the novel method did not exceed 8% at any concentration level. The curves of progress reaction showed a non-linear behavior in samples without TI. A reduction of incubation time from 10 min to 2 min increased the method sensitivity and extended its linear range. A more economical, faster and simpler assay was developed.
KW - Analytical method
KW - Antinutritional factors
KW - Soybean flour
KW - Trypsin inhibitor activity
UR - http://www.scopus.com/inward/record.url?scp=84978804131&partnerID=8YFLogxK
U2 - 10.1016/j.foodchem.2016.07.056
DO - 10.1016/j.foodchem.2016.07.056
M3 - Article
C2 - 27507460
AN - SCOPUS:84978804131
SN - 0308-8146
VL - 214
SP - 156
EP - 161
JO - Food Chemistry
JF - Food Chemistry
ER -