## 1 Introduction  
Reactive oxygen species (ROS), which are generated during normal metabolic processes--primarily in the respiratory chain--pose a significant health risk. In mammals, the energy essential for life is produced in the form of adenosine triphosphate (ATP) through the utilization of oxygen (O\({}_{2}\)). This process involves the electron transport chain (ETC), located in the inner mitochondrial membrane, and results in the generation of both ATP and ROS [1]. Moreover, environmental factors, chronic diseases, and dietary habits may contribute to elevated ROS levels in the body [2]. The most common ROS include the superoxide anion (\({}^{\bullet}\)O\({}_{2-}\)), singlet oxygen (\({}^{1}\)O\({}_{2}\)), and hydrogen peroxide (H\({}_{2}\)O\({}_{2}\)) [3, 4, 5, 6]. These species are implicated in the development of various diseases, including cancer [7]. Over the course of evolution, humans have developed both endogenous and exogenous defense mechanisms against ROS. Endogenous defense mechanisms primarily involve enzymes that regulate ROS levels in living organisms, including superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx) [8]. Exogenous antioxidants, such as phenolic compounds (e.g., hydroxybenzoic acid and hydroxycinnamic acid), are obtained through the diet and play a crucial role in counteracting ROS [9; 10; 11]. These compounds are predominantly found in plant-based foods, particularly in fruits, vegetables, and herbs [12; 13; 14; 15]. The activity or functional capacity of food compounds is assessed using various analytical approaches [16]. Numerous methods for analyzing antioxidant potential have been extensively described in the scientific literature. These methods are generally classified into two main categories: chromatographic and spectrophotometric techniques. Commonly used chromatographic methods for evaluating antioxidant activity include high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), liquid chromatography-electron capture dissociation (LC-ECD), and gas chromatography-mass spectrometry (GC-MS) [17; 18; 19; 20; 21; 22]. This article focuses on spectrophotometric methods, discussing their respective advantages and limitations. Given their widespread use and the substantial discrepancies among spectrophotometric assays, a critical evaluation is warranted. Antioxidant assays are generally classified into two fundamental types: single electron transfer (SET)-based assays and hydrogen atom transfer (HAT)-based methods. In SET-based assays, the progression of the electron exchange reaction is governed by the redox potential of the substrates. Consequently, antioxidants react with an oxidizing agent rather than directly with free radicals [23]. This reaction is typically characterized by a color change in the solution, which reflects the concentration of antioxidants. The magnitude of absorbance change at a specific wavelength correlates with the concentration of antioxidants in the sample. Electron transfer-based methods include the ABTS\({}^{+}\) assay, cupric reducing antioxidant power (CUPRAC) assay, ferric reducing antioxidant power (FRAP) assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and the Folin-Ciocalteu (FC) assay [24; 25]. Hydrogen transfer-based assays exploit the antioxidant's ability to donate a hydrogen atom to a free radical, thereby stabilizing it. The activity and capacity of an antioxidant can be assessed using reaction kinetics by measuring changes in the absorbance curve in the presence or absence of a reducing agent. This category includes the oxygen radical absorbance capacity (ORAC) assay [26]. These methods are characterized by substantial variability among individual assays. To date, no standardized spectrophotometric approach exists for assessing antioxidant potential. This article focuses on a specific niche: the assessment of antioxidant potential in plant-derived foods.