Model of monitoring milk quality using NIR spectroscopy

NIR spektar hrane obuhvaća široko skupove koji proizlaze iz preklapanja apsorpcija odgovarajućih overtona i kombinacija vibracijskih vrpci koji uključuju C–H, O–H i N–H kemijske veze. NIR spektroskopija se danas rutinski koristi za analizu sastava sastojaka hrane, procesnih međuprodukata i gotovih proizvoda. U ovom radu je kao uzorak mjerenja poslužilo kravlje mlijeko različitih proizvođača, različite trajnosti (svježe i trajno) i različitog udjela mliječne masti (0,9; 2,8; 3 i 3,2 % mm). Za uzorke je provedena i ocjena senzorskih karakteristika za koje je procijenjeno su vrlo važne potrošaču (okus, miris, boja i kiselost). Cilj ovog rada bio je pokazati potencijalnu primjenjivost NIR spektroskopije kao vrijedne metode u karakterizaciji mlijeka praćenjem promjene kakvoće tijekom vremena (3 dana, T = 22°C). Obzirom na činjenicu kako je mlijeko je emulzija složene kemijske strukture primijenjena je kemometrija za obradu podataka dobivenih uporabom NIR spektroskopije i provedene senzorske ocjene, na temelju čega je modelom prikazana razlika u kakvoći mlijeka tijekom vremena. Utvrđeno je kako NIR spektroskopija zajedno sa kemometrijom predstavlja optimalnu metodu za praćenje kakvoće mlijeka i njegovog kvarenja tijekom vremena.NIR range of food includes a wide set based on molecular overtone and combination vibrations involving C-H O-H and N-H chemical bonds. NIR spectroscopy is used to analyze the composition of food ingredients, process intermediates and finished products. In this paper as a measured sample served cow's milk produced from different manufacturers, with different shelf life (fresh and long) and different content of fat (0.9, 2.8, 3 and 3.2 % milk fat). For each milk sample was carried out and assessment of sensory characteristics that are valued as very important to the consumer, such as taste, odour, colour and acidity. The aim of this study was to demonstrate the potential applicability of NIR spectroscopy as a valuable tool in the characterization of milk by monitoring changes in quality over time (3 days, T = 22 °C). Due to the fact that milk is an emulsion with a complex chemical structure, chemometrics was applied on data obtained using NIR spectroscopy and conducted sensory evaluation what is shown with models presenting differences in the quality of milk over time. It was found that NIR spectroscopy together with chemometrics is the optimum method for monitoring the quality of milk and its decay over time