Prediction of Zamorano cheese quality by near-infrared spectroscopy assessing false non-compliance and false compliance at minimum permitted limits stated by designation of origin regulations

TALANTA

卷:99

Article

Oca, M. L.¹  Ortiz, M. C.¹  Sarabia, L. A.²  Gredilla, A. E.³  Delgado, D.³ 

[1] Univ Burgos, Dept Chem, Fac Sci, Burgos 09001, Spain

[2] Univ Burgos, Dept Math & Computat, Fac Sci, Burgos 09001, Spain

[3] Agro Technol Inst Milk Technol Stn, Consejeria Agr & Ganaderia Castilla & Leon, Palencia 34071, Spain

关键词: Zamorano cheese;    Partial Least Squares regression;    Near-infrared spectroscopy;    False non-compliance;    False compliance;    ISO 21543:2006;   

DOI  :  10.1016/j.talanta.2012.06.035

来源: Elsevier

【 摘 要 】

Near-infrared transmittance (NIT) spectroscopy was used to predict the percentage in weight of the fat, dry matter, protein and fat/dry matter contents in Zamorano cheeses, protected with a Designation of Origin by the European Union. A total of 42 cheeses submitted to official control were analysed by reference methods. Samples were scanned (850-1050 nm) and predictive equations were developed using Partial Least Squares regression with a cross-validation step. Eight pretreatments independent from the remaining calibration samples were first considered. The most adequate one was that performing the second derivative (using a Savitzky-Golay method with a nine-point window and a second-order polynomial) followed by the standard normal variate transformation. Percentages of the root mean square error in cross-validation, the coefficient of determination and the mean of the absolute value of relative errors found were, respectively, for fat (0.62; 96.16; 1.05), dry matter (0.76; 96.03; 0.83), protein (0.41; 97.82; 0.81) and the fat/dry matter ratio (0.61; 92.51; 0.66). At a 99% confidence level, the trueness of the NIT + PLS methods for fat, dry matter and protein was verified. The official regulation for Zamorano cheese demands minimum permitted limits on the percentages in weight for protein (25%), dry matter (55%) and the ratio of fat to dry matter (45%). The adaptation of both the decision limit and the detection capability to the case of a minimum permitted limit (CD alpha and CD beta, respectively) when a Partial Least Squares calibration is used has been applied for the first time for a food product protected by a Designation of Origin. The values of CD alpha with a probability of false noncompliance equal to 0.05 and of CD beta when, in addition, the probability of false compliance was equal to or less than 0.05, both provided by the corresponding NIT + PLS-based method, were, respectively, for protein (24.78%; 24.57%), dry matter (54.14%; 53.28%) and the fat/dry matter ratio (44.39%; 43.78%). (C) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

Free