title: Determination of free sulphydryl groups in wheat gluten under the influence of different time and temperature of incubation: method validation.
abstract: The aim of the present study was to determine the characteristics of an analytical method for determination of free sulphydryl (SH) groups of wheat gluten performed with previous gluten incubation for variable times (45, 90 and 135min) at variable temperatures (30 and 37°C), in order to determine its fitness-for-purpose. It was observed that the increase in temperature and gluten incubation time caused the increase in the amount of free SH groups, with more dynamic changes at 37°C. The method characteristics identified as relevant were: linearity, limit of detection, limit of quantification, precision (repeatability and reproducibility) and measurement uncertainty, which were checked within the validation protocol, while the method performance was monitored by X- and R-control charts. Identified method characteristics demonstrated its acceptable fitness-for-purpose, when assay included previous gluten incubation at 30°C. Although the method repeatability at 37°C was acceptable, the corresponding reproducibility did not meet the performance criterion on the basis of HORRAT value (HORRAT<2).
authors.affiliation: Institute of Food Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia. Electronic address: sladjana.rakita@fins.uns.ac.rs.
authors.forename: Slađana
authors.initials: S
authors.lastname: Rakita
authors.affiliation: Institute of Food Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia.
authors.forename: Milica
authors.initials: M
authors.lastname: Pojić
authors.affiliation: Institute of Food Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Tomić
authors.affiliation: Institute of Food Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Torbica
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D005983:Glutens / Q000032:analysis*; D015394:Molecular Structure; D013438:Sulfhydryl Compounds / Q000032:analysis*; D013696:Temperature; D013997:Time Factors; D014908:Triticum / Q000737:chemistry*
chemical_list: D013438:Sulfhydryl Compounds; D005983:Glutens
keywords: Free sulphydryl groups; Incubation temperature; Incubation time; Validation protocol