Evaluation of chemical parameters in soft mold-ripened cheese during ripening by mid-infrared spectroscopy

J Dairy Sci. 2007 Jun;90(6):3018-27. doi: 10.3168/jds.2006-656.

Abstract

The suitability of mid-infrared spectroscopy (MIR) to follow the evolution throughout ripening of specific physicochemical parameters in Camembert-type cheeses was evaluated. The infrared spectra were obtained directly from raw cheese samples deposited on an attenuated total reflectance crystal. Significant correlations were observed between physicochemical data, pH, acid-soluble nitrogen, nonprotein nitrogen, ammonia (NH4+), lactose, and lactic acid. Dry matter showed significant correlation only with lactose and nonprotein nitrogen. Principal components analysis factorial maps of physicochemical data showed a ripening evolution in 2 steps, from d 1 to d 7 and from d 8 to d 27, similar to that observed previously from infrared spectral data. Partial least squares regressions made it possible to obtain good prediction models for dry matter, acid-soluble nitrogen, nonprotein nitrogen, lactose, lactic acid, and NH4+ values from spectral data of raw cheese. The values of 3 statistical parameters (coefficient of determination, root mean square error of cross validation, and ratio prediction deviation) are satisfactory. Less precise models were obtained for pH.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonia / analysis
  • Cheese / analysis*
  • Fermentation
  • Food Technology / methods*
  • Hydrogen-Ion Concentration
  • Lactic Acid / analysis
  • Lactose / analysis
  • Nitrogen / analysis
  • Principal Component Analysis*
  • Spectrophotometry, Infrared / methods
  • Spectrophotometry, Infrared / veterinary*
  • Time Factors

Substances

  • Lactic Acid
  • Ammonia
  • Lactose
  • Nitrogen