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Abstract: Near Infrared Spectroscopy (NIRS) was used for the determination of volatile compounds in cheeses allowed to ripen for different times using a remote fibre-optic reflectance probe. To do so, cheeses with known and varying percentages of cow's, ewe's, and goat's milk were elaborated and used as reference material. The volatile compounds determined were: acetaldehyde, ethanol, 1-propanol, 2-butanol, 2-pentanol, 3-methyl-1-butanol, 2-butanone, 2-pentanone, 2-heptanone and 2-nonanone. The regression method employed was the modified partial least squares (MPLS). The calibration results using 67–72 samples of cheese had a correlation coefficients (RSQ) between 0.600 for the 3-methyl-1-butanol and 0.903 for the 2-nonanone. The robustness of the method was confirmed by applying it to twenty new samples of different compositions and ripening times which did not belong to the calibration group. Likewise, the correlations between the factors of influence studied and the volatile compounds were carried out. The results of the NIRS method are comparable with those of the purge-and-trap-gas chromatography-mass spectrometry. [Copyright &y& Elsevier]

The aim of this work was to evaluate sensory changes in grape skins during ripening and to obtain a correlation with their phenolic composition. Flavan-3-ols (monomers and dimers), prodelphinidins, hydroxybenzoic acids, hydroxycinnamic acids, anthocyanins and flavonols were determined by HPLC-DAD-MS. In addition, skin dilaceration, tannic intensity, astringency, acidity, aroma intensity (AI) and type of aroma were evaluated. Multivariate analysis showed the evolution of these samples during ripening and the relationship among sensory scores and phenolic composition of grapes skins. Skin dilaceration, type of aroma and to a lesser extent AI tend to increase during ripening. The contents in the phenolic compounds in grape skins present a similar pattern to the aforementioned sensory parameters. Nevertheless, tannic intensity, astringency, dryness and acidity present an opposite pattern which indicates a decrease of these sensory scores during ripening. El objetivo de este trabajo ha sido evaluar los cambios en los parámetros sensoriales del hollejo de uva durante la maduración y obtener una correlación con su composición fenólica. Se han determinado flavan-3-oles (monómeros y dímeros), prodelfinidinas, ácidos hidroxibenzoicos, ácidos hidroxicinámicos, antocianos y flavonoles mediante HPLC-DAD-MS. Además, se han evaluado los siguientes atributos sensoriales del hollejo: facilidad de dilaceración, intensidad tánica, astringencia, acidez, sequedad, intensidad de aroma y tipo de aroma. El análisis multivariante mostró la evolución de los hollejos a lo largo de la maduración y la relación entre las puntuaciones sensoriales y la composición fenólica de los mismos. La facilidad de dilaceración, el tipo de aroma y en menor medida la intensidad del aroma tienden a aumentar con la maduración, pauta similar a la presentada por los compuestos fenólicos estudiados. Sin embargo, la intensidad tánica, la astringencia, la sequedad y la acidez presentan una pauta opuesta, lo que indica una disminución de estos atributos sensoriales durante la maduración. [ABSTRACT FROM AUTHOR]

Abstract: The results of this work show that it is possible to rapidly quantify calcium, phosphorus, magnesium, potassium and sodium in unknown cheeses elaborated with percentages (0–100%) of milk from different species (cow, ewe, goat) by direct application of the fibre-optic probe on the sample without previous destruction or treatment of the sample. Of the total number of samples, 170 were used to develop the calibration models using the Modified Partial Least Squares (MPLS) regression method and 57 samples were used for external validation. The multiple correlation coefficients (RSQ) and prediction corrected standard errors (SEP (C)) obtained for calcium (0.74, 0.64), phosphorus (0.69, 0.29), potassium (0.86, 0.13), and sodium (0.92, 0.71) in g/kg respectively and magnesium (0.72, 30.9) in ppm, indicated that the models developed allow the determination of Ca, P, K, Na and Mg in unknown samples of cheeses of varying compositions up to 6months of ripening. [Copyright &y& Elsevier]

Abstract: The use of near infrared spectroscopy (NIRS) technology employing a remote reflectance fibre-optic probe (with a 5cm×5cm quartz window) for the analysis of the hydrophilic (HI) and hydrophobic (HO) peptides and the ratio HO/HI was assayed. To do so, cheeses with known and varying percentages of cow’s, ewe’s and goat’s milk were elaborated (112 samples). Ripening controls were performed over 6 months, and the chemical data obtained by reversed-phase high performance liquid chromatography used as reference. The regression method employed was modified partial least squares (MPLS). The multiple correlation coefficients (RSQ) and prediction corrected standard errors (SEP (C)) obtained 0.879 and 1.83% for hydrophilic (HI) and 0.879 and 1.83% for hydrophobic (HO) peptides, respectively, and 0.890 and 0.03% for the ratio HO/HI. The method allows immediate control by direct application of the fibre-optic probe to the cheese without prior sample treatment or destruction. [Copyright &y& Elsevier]

Abstract: The potential of the near infrared spectroscopy (NIRS) technique for the analysis of red paprika for aflatoxin B1, ochratoxin A and total aflatoxins is explored. As a reference, the results from a chromatographic method with fluorescence detection (HPLC-FD) following an immunoaffinity cleanup (IAC) were employed. For the NIRS measurement, a remote reflectance fibre-optic probe was applied directly onto the samples of paprika. There was no need for pre-treatment or manipulation of the sample. The modified partial least squares (MPLS) algorithm was employed as a regression method. The multiple correlation coefficients (RSQ) and the prediction corrected standard errors (SEP(C)) were respectively 0.955 and 0.2μgkg−1, 0.853 and 2.3μgkg−1, 0.938 and 0.3μgkg−1 for aflatoxin B1, ochratoxin A and total aflatoxins, respectively. The capacity for prediction of the developed model measured as ratio performance deviation (RPD) for aflatoxin B1 (5.2), ochratoxin A (2.8) and total aflatoxins (4.4) indicate that NIRS technique using a fibre-optic probe offers an alternative for the determination of these three parameters in paprika, with an advantageously lower cost and higher speed as compared with the chemical method. Content of aflatoxin B1 and total aflatoxins are the parameters currently employed by the food regulations to limit the levels of the four aflatoxins in many foodstuffs. In addition, aflatoxin B1 itself is an excellent indicator for aflatoxins’ contamination since it is always the most abundant and toxic. [Copyright &y& Elsevier]

Abstract: In the present work we studied the use of near infrared spectroscopy (NIRS) technology employing a remote reflectance fibre-optic probe (with a 5cm×5cm quartz window) for the analysis of the percentage of milk (cow''s, ewe''s and goat''s) used in the elaboration of cheeses with different ripening times. To do so, cheeses with known and varying percentages of cow''s, ewe''s and goat''s milk were elaborated (112 samples with milk collected in winter and 112 samples with milk collected in summer) and used as reference material, and ripening controls were performed over 6 months. The method allows immediate control of the cheese without prior sample treatment or destruction by direct application of the fibre-optic probe to the sample. The regression method employed was modified partial least squares (MPLS). Of all the samples (224), 200 formed to so-called calibration set and the other 24 were used for external validation. The calibration results obtained using 200 samples of cheese allowed the percentage of cow''s, ewe''s and goat''s milk to be measured. The multiple correlation coefficients (RSQ) and prediction corrected standard errors (SEP(C)) obtained were respectively, 0.834 and 11.6% for cow''s milk; 0.871 and 9.8% for goat''s milk; 0.880 and 10.6% for ewe''s milk. The ratio performance deviation (RPD) values obtained indicate that the NIRS equations can be applied to unknown samples. [Copyright &y& Elsevier]

Abstract: In the present work, we study the use of near infra-red spectroscopy (NIRS) technology together with a remote reflectance fibre-optic probe for determination of the major components in bee pollen. The method allows immediate control of the bee pollen without prior sample treatment or destruction through direct application of the fibre-optic probe to the sample. The regression method employed was modified partial least squares (MPLS). The calibration results obtained using 45 samples of bee pollen allowed the measurement of protein, moisture, ash, reducing sugars, and pH with multiple correlation coefficients (RSQ) and prediction corrected standard errors (SEPC) of 0.91, 0.56% for protein, of 0.78 and 0.49% for moisture; 0.92 and 0.049% for ash; 0.81 and 1.32g of glucose/100g of bee pollen; 0.84 and 0.15 for pH, respectively. The prediction capacity of the pattern was checked by applying it to samples of unknown pollen in external validation. [Copyright &y& Elsevier]

Abstract: The use of NIRS (near infra-red spectroscopy) technology together with a remote-reflectance fibre-optic probe was studied for the analysis of ewe’s cheese texture. The cheeses were elaborated with milk from three breeds of sheep (Castellana, Churra and Assaf) with different somatic cell counts (SCC) (lower than 500,000 cells mL−1; between 1,000,000 and 1,500,000cells mL−1, and more than 2,500,000cells mL−1) and ripened for 12 months, thus 96 samples were obtained. At each ripening time NIRS spectra were recorded and instrumental texture were determined as Warner–Bratzler shear force using a TX-T2iplus. The regression method employed was modified partial least squares (MPLS). The calibration, with the multiple correlation coefficients (RSQ), 0.961 and standard error of prediction (SEP(C)) of 2.1N, allows determining texture in the range 0.0–49.0N. The ratio performance deviation (RPD) value obtained, 5.4, indicate that the NIRS equation obtained was applicable to unknown samples. [Copyright &y& Elsevier]

Abstract: The objective of this work is to evaluate by near infrared reflectance (NIR) spectroscopy different attributes, visual (presence of holes), taste (salty, buttery flavour), texture (hardness, chewiness, creamy), rancid flavour and other sensations (pungency, retronasal sensation), in cheeses elaborated with milk of variable composition (cow, ewe, goat), collected in winter and summer and subject to ripening times of 4 and 6months, taking as reference data the evaluation of the sensorial properties obtained by a panel of eight trained experts. The sensorial properties are quantified by NIR spectra with a remote reflectance fibre optic probe applying the probe directly to the cheese samples and the calibration equations are developed by using modified partial least-squares (MPLS) regression for 50 samples of cheese. The robustness of the analytic method is confirmed by applying it to 14 samples of unknown cheeses. [Copyright &y& Elsevier]