Determination of the lactose content in low-lactose milk using Fourier-transform infrared spectroscopy (FTIR) and convolutional neural network.

Demand for low lactose milk and milk products has been increasing worldwide due to the high number of people with lactose intolerance. These low lactose dairy foods require fast, low-cost and efficient methods for sugar quantification. However, available methods do not meet all these requirements. In this work, we propose the association of FTIR (Fourier Transform Infrared) spectroscopy with artificial intelligence to identify and quantify residual lactose and other sugars in milk. Convolutional neural networks (CNN) were built from the infrared spectra without preprocessing the data using hyperparameter adjustment and saliency map. For the quantitative prediction of the sugars in milk, a regression model was proposed, while for the qualitative assessment, a classification model was used. Raw, pasteurized and ultra-high temperature (UHT) milk was added with lactose, glucose, and galactose in six concentrations (0.1-7.0 mg mL-1) and, in total, 432 samples were submitted to convolutional neural network. Accuracy, precision, sensitivity, specificity, root mean square error, mean square error, mean absolute error, and coefficient of determination (R2) were used as evaluation parameters. The algorithms indicated a predictive capacity (accuracy) above 95% for classification, and R2 of 81%, 86%, and 92% for respectively, lactose, glucose, and galactose quantification. Our results showed that the association of FTIR spectra with artificial intelligence tools, such as CNN, is an efficient, quick, and low-cost methodology for quantifying lactose and other sugars in milk.

Aspectos epidemiológicos da Bordetella pertussis / Epidemiological aspects of Bordetella pertussis

A coqueluche é uma doença infecciosa aguda e transmissível que compromete principalmente o aparelho respiratório (traquéia e brônquios) e se caracteriza por paroxísmos de tosse seca. É modernamente considerada uma síndrome (Síndrome pertussis), podendo ser causada por vários agentes (Bordetella, pertussis, B. parapertussis, B. broncheseptica e adenovírus 1, 2, 3 e 5), entretanto, apenas a B. pertussis está associada com as coqueluches endêmicas e epidêmicas. A B. pertussis é um bacilo gram-negativo, aeróbio, não esporulado, imóvel e pequeno, provido de cápsula e fímbrias, sendo o homem o seu único reservatório natural. A transmissão da doença se dá principalmente pelo contato direto de pessoa doente com pessoa susceptível, através de gotículas de secreção, eliminada por tosse, espirro ou ao falar. O indivíduo torna-se resistente à doença após adquiri-la ou após receber imunização básica com DTP. Daremos ênfase na epidemiologia da doença no Brasil e no mundo.