RESUMEN
Three different NIR equipment were evaluated based on their ability to predict superficial water activity (a(w)) and moisture content in two types of fermented sausages (with and without moulds on surface), using partial least squares (PLS) regression models. The instruments differed mainly in wavelength range, resolution and measurement configuration. The most accurate equipment was used in a new experiment to achieve robust models in sausages with different salt contents and submitted to different drying conditions. The models developed showed determination coefficients (R(2)(P)) values of 0.990, 0.910 and 0.984, and RMSEP values of 1.560%, 0.220% and 0.007% for moisture, salt and a(w) respectively. It was demonstrated that NIR spectroscopy could be a suitable non-destructive method for on-line monitoring and control of the drying process in fermented sausages.
Asunto(s)
Manipulación de Alimentos , Productos de la Carne/análisis , Espectroscopía Infrarroja Corta/métodos , Agua/análisis , Desecación , FermentaciónRESUMEN
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Asunto(s)
Humanos , Investigación Biomédica/tendencias , Institutos Gubernamentales de Investigación , Investigación sobre Servicios de Salud/tendencias , Acreditación de Instituciones de SaludRESUMEN
This paper describes the ability of near infra-red reflectance (NIR) spectroscopy to predict moisture, water activity (aw) and NaCl content at the surface of dry-cured ham during the process. A Fourier Transform (FT) NIR spectrometer and two probes (on-contact and remote) were tested directly on the surface (gracilis muscle) of 98 hams during the process. The highest precision was achieved when two spectra per sample were used in the predictive model development. The models based on the remote measurement probe yielded acceptable results with determination coefficients (r2) of 0.93, 0.62 and 0.91 and residual predictive deviation (RPD) of 3.74, 1.63 and 3.33 for moisture, aw and NaCl content, respectively. These results show that NIR measurements could be included in the control system of the resting and drying processes to prevent crusting in dry-cured ham.
RESUMEN
The feasibility of near-infrared spectroscopy (NIR) for predicting parameters related to the drying process of fermented sausages (water activity (a(w)), moisture, and NaCl contents) was assessed. A FT-NIR spectrometer and two spectra acquisition setups with contact and remote probes were tested. NIR calibration models were developed using 207 samples scanned between 12,000 and 4000cm(-1) (833-2500nm) in reflectance mode. Partial least squares (PLS) regression was used to process spectra and develop calibrations. Predictive models for moisture, a(w) and NaCl yielded 0.997, 0.988 and 0.974 determination coefficients in prediction (R(p)(2)) respectively with the on-contact probe method, and 0.998, 0.985 and 0.974 respectively with the remote measurement head method. Furthermore 0.675, 0.006 and 0.117 root mean square errors of prediction (RMSEP) were achieved with the contact probe method, and 0.622, 0.007 and 0.116 with the remote measurement head method. The results confirmed that NIR spectroscopy is an useful technique for predicting moisture and NaCl and suggest it could also be useful to predict a(w) on the surface of fermented sausages. Both setups are appropriate for further on-line applications for monitoring drying processes in a non-destructive way with non-significant differences in the predictive accuracy.