Exploring smart phone based colorimetric technology for on-site quantitative determination of adulterant...

There is a great concern regarding the safety of milk not only for human health but also for its economic consequences. The portable sensing devices, which can collect and analyze data within food supply chains at critical control points are lacking. Smart phones have now emerged as an integral part of each home, lab, farm and factory. It is having a provision of digital camera and computation; with widespread applicability including food analysis. The use of soda as a milk neutralizer is a usual practice but has a detrimental human health impact. This investigation explored an easy, economic, fast, repeatable, and field applicable Smartphone-based sensing technology, which was standardized and in-house validated for the quantitative determination of neutralizer in milk samples. The method had simple steps of spot-test response and digital image evaluation with the Red Green Blue process. The linearity of the method was shown by analytical curves ranging from 0.125% (1250 ppm) to 1% (10,000 ppm) that were characterized by R² > 0.99. The limit of detection of 0.11% demonstrated the sensitivity of the method which was found better than the existing wet chemical spot test. Comparison with the existing spectroscopic method revealed no statistically significant difference between the observations using paired t-test at a confidence level of 95%.