RESUMEN
A rapid method for determining the carbonyl value of frying oils has been developed using Fourier-transform infrared (FTIR) spectroscopy and chemometrics. One hundred and fifty-six frying oils with different carbonyl values were collected from an actual potato frying process. FTIR spectra in the range of 4000-650 cm(-1) were scanned with a FTIR spectroscopy apparatus using the attenuated total reflectance (ATR) method. A good calibration model was obtained using the partial least-squares (PLS) regression method with full cross validation for predicting the carbonyl value of frying oils. For the model, the coefficients of determination (R(2)), standard errors of cross validation (SECV) and standard errors of prediction (SEP) were 0.99, 1.87 µmol g(-1) and 1.93 µmol g(-1), respectively. Moreover, standard deviation ratios of reference data in the validation sample set to the SEP were higher than 3. This study shows that the carbonyl value of frying oils can be successfully determined to a high accuracy using FTIR spectroscopy combined with PLS regression.
Asunto(s)
Culinaria/métodos , Ácidos Grasos Monoinsaturados/química , Ácidos Grasos no Esterificados/análisis , Análisis de los Alimentos/métodos , Calidad de los Alimentos , Calor , Aceites de Plantas/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Calibración , Análisis de los Mínimos Cuadrados , Aceite de Brassica napus , Sensibilidad y Especificidad , Espectroscopía Infrarroja por Transformada de Fourier/instrumentaciónRESUMEN
A 52-year-old woman was referred to our hospital for treatment of urachal cancer. She complained of supurapubic dull pain and gross hematuria. Computed tomography and magnetic resonance imaging showed a non-papillary sessile tumor, which was located on the dome of the bladder and invaded the small intestine. The tumor was diagnosed as Sheldon's stage IIIC urachal cancer. After three courses of neoadjuvant chemotherapy with FOLFOX4 (oxaliplatin, 5-FU and leukovolin), the tumor was reduced from 7 x 6 cm to 5.5 x 5 cm in size. Consequently, the patient underwent an en-bloc resection of the urachal tumor with the dome of the bladder and the parts of the ileum invaded by the tumor. One course of adjuvant chemotherapy (FOLFOX4) was performed. Surgical specimen revealed histologically well differentiated squamous carcinoma and invasion to the propria of the ileum. The surgical margins were negative for the cancer. For 1.5 years after the surgery, no local recurrence or distant metastasis has been observed.