Abstract
Vitamin A (VA) deficiency continues to be a major global health issue, despite measures to increase VA intake via consumption of staple foods such as edible oil. Portable quantitative and semiquantitative devices or test kits for internal quality control have the potential to overcome some of the limitations of traditional methods of testing, such as centralized laboratory, expensive equipment, and specially trained staff. This landscape analysis and comprehensive systematic mini-review catalogs and summarizes evidence on the analytical performance of portable quantitative and semiquantitative devices and test kits for the analysis of VA in edible oil. Studies or reports detailing the usability and validation of portable devices and/or test kits, as well as studies comparing device/test kit performance to a reference standard such as high-performance liquid chromatography (HPLC), were included. Identified devices and test kits were compared for performance versus the reference standard, usability, availability, and other characteristics. We identified four portable methods: two devices, the iCheck CHROMA and iCheck Chroma 3 from BioAnalyt; and two test kits, the QuickView from Bagco Enterprises and the Strategic Alliance for the Fortification of Vegetable Oils (SAFO) Test Kit by Badische Anilin and Soda Fabrik (BASF). Included studies reported the following: an internal validation of the portable method, a comparison of the portable method against a reference standard, a comparison of the portable method against another portable method, and several videos and company websites, which detailed device characteristics. iCheck CHROMA and QuickView quantified VA concentrations with high accuracy and precision compared to the reference standard for field-based quantification, were user-friendly, and provided results within 5 min. iCheck Chroma 3 requires more robust validation against a reference standard. We did not find data on internal validation or comparison against a reference standard for the current version of the SAFO test. Compared to QuickView and SAFO, the iCheck devices can transfer results to a hard drive or the Web, have an online order form for purchase, and meet a minimal set of criteria for point-of-need devices. iCheck, QuickView, and SAFO can quantify VA concentrations in the edible oils tested and determine whether a fortified oil meets country standards. Additional research is needed to validate these devices and test kits across additional oil types and document the ability to meet the minimal criteria for point-of-need devices suggested in this mini-review. Validation against a reference standard is required for SAFO. The limited number of portable methods available may be due to market saturation. Future market and use case analyses to inform the market size and utility of the different tests with publicly available data will allow new manufacturers, particularly those in lower-to-middle-income countries, to enter the market.