Evaluation of the total antioxidant capacity of solid matrices without extraction steps is a very interesting
alternative for food researchers and also for food industries. These methodologies have been denominated QUENCHER from
QUick, Easy, New, CHEap, and Reproducible assays. To demonstrate and highlight the validity of QUENCHER (Q) methods,
values of Q-method validation were showed for the first time, and they were tested with products of well-known different
chemical properties. Furthermore, new QUENCHER assays to measure scavenging capacity against superoxide, hydroxyl, and
lipid peroxyl radicals were developed. Calibration models showed good linearity (R2 > 0.995), proportionality and precision (CV
< 6.5%), and acceptable detection limits (<20.4 nmol Trolox equiv). The presence of ethanol in the reaction medium gave
antioxidant capacity values significantly different from those obtained with water. The dilution of samples with powdered
cellulose was discouraged because possible interferences with some of the matrices analyzed may take place.
