Portable optical instrumentation for the evaluation of the onsite antioxidant scavenging capacity assay

The aim of this study was to develop a portable optical instrument to measure the scavenging capacity of standard antioxidants. The developed instrument performed on-site assays for four antioxidant capacities, namely 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging activity, 2,2′-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) free radical scavenging activity, total phenol content, and total flavonoid content. Because each item required distinct wavelengths and operating procedures for detection, the developed instrument featured automatic, high-speed, and multi-function capabilities. The results revealed that the correlation between the absorbance values determined using the proposed instrument and a commercial spectrophotometer ranged from 0.94 to 0.9997 based on assays of the four antioxidant capacities. Hence, the results of the proposed instrument were strongly correlated with those of the commercial spectrophotometer. This instrument provides a low-cost, portable, and rapid platform for on-site antioxidant scavenging capacity assays.