Detecção de soro de queijo em leite por espectrofotometria no infravermelho

• Autor(a) principal: Carvalho, Bruna Mara Aparecida de
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2917
• topic: Soro de queijo; Espectrofotometria; Detecção de fraude; Cheese whey; Spectrophotometry; Fraud Detection; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS

The detection in real time of whey in milk is a particularly complex problem, because the usual analysis for determination of milk chemical composition cannot be accomplished quickly. In this work, a method for detection of whey added in powder milk was developed through the technique of the mid-infrared spectroscopy (MIR). Initially, spectral data of milk samples added with glycomacropeptide (GMP) in different proportions were appraised by principal component analysis (ACP), with the purpose of selecting the range of wavelength which this composition appears in a spectrum. After the wavelength selection, specters of milk sample added with whey in different proportions were determined. In order to detect this adulteration, multivariate analysis techniques were used, such as principal component analysis (ACP), usually used as method of exploratory analysis; discriminant analysis (AD), which is used for the classification of samples and partial least squares (PLS), the most used in calibration problems. The statistical techniques evaluated in the present work were successfully used in the selection of the wavelength range, which the GMP appears in the spectrum, and for detection of whey in milk samples. In this way, statistical models were calibrated for detection and quantification of whey in unknown samples.