Discriminant analysis of Olomouc curd cheese by Fourier transform near infrared spectroscopy

Abstract

We used the discriminant analysis of curd cheese during storage by Fourier transform near infrared spectroscopy method (FT-NIRs). Olomouc curd cheese samples were stored at 5 and at 20°C during seven weeks. The spectra of samples were measured at the integration sphere in reflectance mode with the use of a compressive cell in the spectral range of 10 000-4000 cm-1 with 100 scans. Ten principal components were used for all the calibration models. Great similarity between the samples stored at 5 and 20°C was found. Twelve samples stored at 20°C for 1 week and 2 samples stored at 20°C for 2 weeks were classified as samples stored at 5°C. Different results were found out by comparing the storage time. 100% variability was described between the spectra scanned in different weeks of storage at 5°C and 99.9% variability was obtained for the samples stored at 20°C. Thus, the discriminant analysis of Olomouc curd cheese by FT-NIRs is a suitable method for the determination of ripening time.

Keywords

• ripening
• mahalanobis distance