Development Of Fourier Transform Near Infrared Spectroscopy Methods For The Rapid Quantification Of Starch And Cellulose In Mozzarella And Other Italian-Type Cheeses

Abstract

Flow-aids consisting of starch and cellulose are added to prevent caking and sticking in grated and shredded cheese and are used as carriers for added antimycotics to prevent mold growth. The accurate quantification of these flow-aids involves difficult wet-chemistry methods. When too little antimycotic is added, quality issues can occur. Conversely, when too much flow-aid is added in order to dilute the cheese for economic gain, the reputation of the dairy industry is damaged. As a way to prevent the over or underuse of these ingredients, Fourier Transform Near-Infrared Spectroscopy (NIR) could be useful. The goal of this research was to investigate whether calibrations could be made to quantify starch and cellulose in Asiago, Parmesan, and Romano cheeses, alone and separately. Samples of Asiago, Parmesan, and Romano loafs were shredded, and 0 – 5.66% of a starch/cellulose flow-aid was added. Treatments were ground, weighed, formed into a ball and pressed in the middle of the glass petri dish to create a homogenous scanning surface. Samples were scanned using a BUCHI NIRFlex N-500 FT-NIR spectrometer (BUCHI Labortechnik AG, CH). NIRCal 5.2 Chemometric Software (BUCHI Labortechnik) was used to analyze the spectra after first dividing the spectra of the 2,367 samples into 1,578 calibration and 789 validation samples. The spectra were treated with standard normal variate to minimize variations and optimize the calibration. The calibrations obtained had an r2 greater than 0.94 and worked better when they were specific to one specific cheese (ie. Asiago) instead of one kind of cheese (ie. Hard-grated cheese). Future research will determine if cellulose and starch can be identified and quantified separately in the same sample, and the effect of different starch and cellulose types on quantification.