Evaluation of chemical parameters in soft mold-ripened cheese during ripening by mid-infrared spectroscopy.
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.
Martín-del-Campo
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Unité Mixte de Recherche Génie et Microbiologie des Procédés Alimentaires, Institut National de la Recherche Agronomique, Agro Paris Tech, F-78850 Thiverval-Grignon, France.
Picque
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Cosío-Ramírez
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R
Corrieu
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G
D000641:Ammonia / Q000032:analysis; D002611:Cheese / Q000032:analysis*; D005285:Fermentation; D005524:Food Technology / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000032:analysis; D007785:Lactose / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D025341:Principal Component Analysis; D013055:Spectrophotometry, Infrared / Q000379:methods / Q000662:veterinary*; D013997:Time Factors
D019344:Lactic Acid; D000641:Ammonia; D007785:Lactose; D009584:Nitrogen