An iPhone-based digital image colorimeter for detecting tetracycline in milk

PhotoMetrix: An Application for Univariate Calibration and Principal Components Analysis Using Colorimetry on Mobile Devices

“…3 After the image acquisition, several processing techniques can be applied to enhance the visualization of some features of the images; there is an increasing interest in image analysis associated with multivariate analysis tools, such as principal components analysis (PCA), which are appropriate for the interpretation of the multiple types of information contained in an image. 1 In the most recent years, different research groups have used image analysis as an analytical tool in several distinct areas of knowledge: in food science and technology for visual inspection of fruit 4 and for the development of a portable iPhone-DIC system for the quantification of tetracycline residues in milk; 5 in forensic applications, where the Simon presumptive color test is used in combination with a built-in digital camera on a mobile phone to detect methamphetamine; 6 and for the diagnosis of kidney failure through the ascertainment of creatinine in urine samples. 7 These tools were also used in the development of a simple, fast, and safe method to identify adulteration of cow's milk based on the building of color histograms in RGB and/or HSI scales.…”

Inhibition of Mushroom Tyrosinase Activity by Orsellinates

“…The purpose of the present study was to investigate the effect that resorcinol (1), orcinol (2), lecanoric acid (3), orsellinic acid (4), and methyl (5), ethyl (6), n-propyl (7), n-butyl (8), iso-propyl (9), sec-butyl (10), tert-butyl (11), n-pentyl (12), n-hexyl (13), n-octyl (14), and n-cetyl orsellinates (15) exert on tyrosinase activity. The inhibition mechanism involved in n-octyl orsellinate (14) was also investigated.…”

“…7) Tyrosinase inhibitors are often structurally analogous to phenolic substrates, which generally show competitive inhibition. A number of naturally occurring tyrosinase inhibitors have been described, mostly phenols and polyphenols, 8) resorcinol derivatives, [9][10][11] benzoic acid and pyridine derivatives, 12,13) gallate derivatives, 14) and vanillin derivatives. 15) However, only a few compounds are known to serve as effective tyrosinase inhibitors, owing to high toxicity, low activity, or economic factors.…”

Desenvolvimento E Validação De Metodologia Analítica Baseada Em Imagens Digitais De Spot Tests Para Determinação De Etanol Em Cachaça

“…Os métodos analíticos baseados em imagens digitais de spot test têm se tornado alternativas promissoras para a determinação de analitos de interesse alimentício, uma vez que o spot test (testes em escala reduzida, pontuais) envolve procedimentos simples, rápidos, práticos e baseados em baixo consumo de reagentes SANTOS, 2016;MASAWAT;HARFIELD;NAMWONG, 2015;MATIAS;VILA;TUBINO, 2004). Além disso, o desempenho dos dispositivos digitais tem apresentado melhora significativa nos últimos anos, enquanto seus custos têm reduzido (PESSOA et al, 2017).…”