Pocket test for instantaneous quantification of starch adulterant in milk using a counterfeit banknote detection pen

• Published in: Food chemistry Vol. 405; p. 134844
• Main Authors: Andrade, Larissa M., Romanholo, Pedro V.V., Ananias, Ana Carolina A., Venancio, Kamylla P., Silva-Neto, Habdias A., Coltro, Wendell K.T., Sgobbi, Livia F.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 30.03.2023
• Subjects: Colorimetric detection; Food adulteration; Microanalysis; Milk; Paper-based device; Starch; Food adulteration; Paper-based device; Starch; Microanalysis; Milk; Colorimetric detection
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2022.134844

[Display omitted] •A pocket test for instantaneous detection of adulterant starch in milk.•User-friendly and reagent-free paper-based platform for non-skilled users.•A selective colorimetric sensing platform for starch detection in milk. This work presents a paper-based analytical device for instantaneous detection of adulterant starch in commercial milk. A highly efficient strategy was based on the well-established starch/iodine complex formation reaction by using a commercial counterfeit detection pen (CDP). Employing the CDP as a user-friendly and reagent-free approach to modify confined regions of a paper substrate readily promotes the reaction with starch in milk. The resulting color change can be analyzed by a digital scanner or via portable smartphone cameras. The proposed device provided a linear behavior in the concentration range between 0.05 and 1 %, with limits of detection and quantification equal to 0.05 % and 0.17 %, respectively. The sensor shows a very stable readout for many interferents, except for sodium hydroxide at higher concentrations (>1.0 %). Recovery tests performed at different concentration levels yielded values from 96.2 to 116.8 %, demonstrating its potential for quantitative analysis.